Hydrodistillation apparatus, method, and system

Abstract

We provide steam distillation systems. [Solution] The system includes a steam distillation device configured to receive a certain volume of source water from a fluid source and produce a distillate, the device comprising: a first heat exchanger comprising a concentrate flow path having a concentrate output; a distillate flow path having a distillate output; at least one source constant ratio valve; and at least a portion of the distillate flow path; and a second heat exchanger comprising at least a portion of the concentrate flow path, wherein the first and second heat exchangers are in fluid flow communication with a fluid source; and a distillate sensor assembly communicating with the distillate flow path and located downstream of the first heat exchanger, the distillate sensor assembly comprising a distillate sensor assembly configured to generate a distillate temperature measurement; and a controller configured to control the source constant ratio valve.

Description

[Technical Field]

[0001] The present invention relates to water distillation, and more specifically to steam distillation apparatus, methods, and systems. [Background technology]

[0002] (Background information) Reliable sources of purified water are essential for the majority of humanity. For example, Canada's Agency for International Development reports that approximately 1.2 billion people lack access to safe drinking water. Published reports indicate that millions of people, primarily children, die each year due to water-related illnesses. Many water purification techniques are well known, including carbon filters, chlorination, pasteurization, and reverse osmosis. Many of these techniques are significantly affected by variability in water quality and do not address a variety of common contaminants that may be found in water sources in developing countries and elsewhere, such as bacteria, viruses, organic matter, arsenic, lead, mercury, and pesticides. Some of these systems require access to sources of consumables such as filters or chemicals. Furthermore, some of these techniques are only well suited to centralized, large-scale water systems, requiring both significant infrastructure and highly trained operators. The ability to produce reliable purified water on a smaller, decentralized scale, without the need for consumables and constant maintenance, regardless of the water source, is highly desirable, especially in the developing world.

[0003] The use of steam compression distillation for water purification is well-known and can address many of these concerns. However, poor financial resources, limited technological assets, and low population density in much of the developing world, which make it impractical to build centralized, large-scale water systems, also limit the availability of adequate, accessible, and reliable electricity to operate steam compression distillation systems and hinder the ability to properly maintain such systems. In such circumstances, improved vapor compression distillation systems and associated components that increase efficiency and production capacity while reducing the power budget required for system operation and the amount of system maintenance required may offer a solution. [Overview of the project] [Means for solving the problem]

[0004] (summary) According to one embodiment of the present disclosure, a steam distillation system for providing a distillate at a controlled temperature is disclosed. The steam distillation system is a steam distillation device configured to receive a certain volume of source water from a fluid source and produce a distillate, and includes a concentrate flow path having a concentrate output, a distillate flow path having a distillate output, a first heat exchanger comprising at least a portion of the distillate flow path, and a second heat exchanger comprising at least a portion of the concentrate flow path, wherein the first and second heat exchangers are in fluid flow communication with a fluid source, a distillate sensor assembly communicating with the distillate flow path and located downstream of the first heat exchanger, configured to generate a distillate temperature measurement, and a controller configured to control the source ratio, which receives the distillate temperature measurement, determines the difference between a first target temperature and the distillate temperature measurement, and is configured to divert source water from the fluid source between the first and second heat exchangers based on the difference between the first target temperature and the distillate temperature measurement.

[0005] According to one embodiment of the present disclosure, a water purification system for outputting a distillate at a controlled temperature may include a distillation device that selectively fluidizes a fluid source via a set of source constant ratio valves. The distillation device may each have a concentrate output and a distillate output, coupled to a concentrate flow path and a distillate flow path. The system may further include a first heat exchanger including a portion of the distillate flow path and a second heat exchanger including a portion of the concentrate flow path. The flow path from the fluid source may be in a heat exchange relationship with each of the first and second heat exchangers. The system may further include a distillate sensor assembly communicating with a distillate flow path downstream of the portion of the distillate flow path contained within the first heat exchanger. The distillate sensor assembly may be configured to generate a distillate temperature measurement. The system may further include a controller that controls the operation of a source-specific valve and, in a first operating mode, is configured to split the inflow from the fluid source between a first heat exchanger and a second heat exchanger based on a delta between a first target temperature and a measured distillate temperature.

[0006] In some embodiments, the controller may be configured to determine a total source constant valve duty cycle that determines the amount of inflow from the fluid source. In some embodiments, the system may further include a concentrate reservoir and a concentrate level sensor. The controller may be configured to determine a total source constant valve duty cycle based on a concentrate accumulation rate and a target concentrate accumulation rate calculated from the level measurement output of the concentrate level sensor. In some embodiments, the controller may be configured in a second operating mode to control the operation of the source constant valves, allocating the entire total source constant valve duty cycle to the source constant valve controlling the source flow to the second heat exchanger, and opening the source constant valve controlling the source flow to the first heat exchanger for an additional duty cycle below a predefined limit. In some embodiments, the predefined limit may be selected from a list consisting of 5%, 2%, less than 2%, and zero. In some embodiments, the first operating mode may be a low-temperature distillate production state, and the second operating mode may be a high-temperature distillate production state. In some embodiments, the controller may be configured to open a source control valve that controls the source flow to the first heat exchanger based on a second target temperature and the delta between the second target temperature and the current concentrate temperature in a second operating state. In some embodiments, the second target temperature may be at least 65°C higher than the first target temperature. In some embodiments, the second target temperature may be at least 50°C higher than the first target temperature. In some embodiments, the second target temperature may be above 95°C and below 100°C. In some embodiments, the second target temperature may be 96°C. In some embodiments, the second target temperature may be at least twice the first target temperature. In some embodiments, the second target temperature may be at least 2.5 times the first target temperature. In some embodiments, the second target temperature may be at least 3.5 times the first target temperature. In some embodiments, the system may further include an evaporator level sensor located in the evaporator reservoir, which is in fluid communication with the evaporator of the distillation device.In a second mode, the controller may be configured, at least partially, to determine the total source constant ratio valve duty cycle based on an evaporator level data signal indicating the level of the water column in the evaporator reservoir. In some embodiments, the first target temperature is at least 20°C, but may be 25°C or less. In some embodiments, the system may further include a source fluid temperature sensor. The controller may be configured, at least partially, to determine the first target temperature based on a source fluid temperature measurement received from the source fluid temperature sensor. In some embodiments, the system may further include a concentrate sensor assembly communicating with a concentrate flow path downstream of the portion of the concentrate flow path contained within the second heat exchanger. The concentrate sensor assembly may be configured to generate a concentrate temperature measurement. In some embodiments, the controller is configured, at least partially, to open the source constant ratio valve controlling the source flow to the second heat exchanger based on a delta between a third target temperature and a concentrate temperature measurement. In some embodiments, the third target temperature may be the historical average of the concentrate temperature. In some embodiments, the controller may be configured, at least partially, to open the source constant valves that control the source flow to the second heat exchanger based on a minimum limit. In some embodiments, the minimum limit may exceed a predefined duty cycle or a predefined percentage of the combined duty cycle for all of the source constant valves. In some embodiments, the predefined duty cycle may be 5%. In some embodiments, the predefined percentage may be 10%. In some embodiments, the controller may be located in an electronics box that is in a heat transfer relationship with the flow path from the fluid leading to the source second heat exchanger. In some embodiments, the controller may determine an electronics box cooling duty cycle command and, at least partially, be configured to open the source constant valves that control the source flow to the second heat exchanger based on the electronics box cooling duty cycle command. In some embodiments, the electronics box cooling duty cycle may be determined, at least in part, based on a delta between the target electronics box temperature and an electronics box temperature measurement collected from an electronics box temperature sensor configured to measure the temperature of the electronics box and communicate data with a controller. In some embodiments, the distillate sensor assembly may include a redundant temperature sensor. In some embodiments, the distillate sensor assembly may include a redundant temperature sensor and a redundant conductive sensor. In some embodiments, the first and second heat exchangers may be helical and formed by winding the heat exchanger around the outside of the distillation device.

[0007] According to one embodiment of the present disclosure, a fluid distillation apparatus may comprise at least one controller and a source inlet that selectively communicates with a fluid source via at least one valve. The fluid vapor distillation apparatus may further comprise an evaporator that communicates with the source inlet. The fluid vapor distillation apparatus may further comprise a vapor chamber coupled to the evaporator and communicating with a compressor. The fluid vapor distillation apparatus may further include a concentrate reservoir, which is attached to the steam chamber via an inlet path. The concentrate reservoir may be positioned laterally to the steam chamber such that at least a portion of the concentrate reservoir is at the same height as the steam chamber. The fluid vapor distillation apparatus may further include a condenser, which is in fluid communication with the outlet of a compressor via a linear flow path. The linear flow path may include a condenser inlet having a windowed compartment with a plurality of openings. The openings may establish the flow path from the condenser inlet to the condenser. The fluid vapor distillation apparatus may further include a product process flow reservoir, which is coupled to the condenser by a product reservoir inlet. The product process flow reservoir may be positioned laterally to the condenser such that at least a portion of the product process flow reservoir is at the same height as the condenser.

[0008] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a plate. The plate may have a compartment that extends into the concentrate reservoir at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate reservoir and divide the concentrate reservoir into a first part and a second shielding part. In some embodiments, the fluid vapor distillation apparatus may further include a vent path extending from the concentrate reservoir into the steam chamber. In some embodiments, the vent path may extend substantially parallel to the inflow path with respect to gravity and be located above it. In some embodiments, the product reservoir inlet may be adjacent to the product accumulation surface of the condenser. In some embodiments, the compressor may be driven by a motor mounted in a receiving well fitted into the side of the steam chamber. In some embodiments, the compressor may include an impeller that passes through at least a portion of the steam chamber and rotates about an axis that is offset from but parallel to the center of the longitudinal axis of the steam chamber.

[0009] According to another embodiment of the present disclosure, the steam distillation apparatus may comprise a reservoir and an evaporator having a first side in communication with the reservoir. The evaporator may have a second side in fluid communication with a steam chamber. The steam distillation apparatus may further comprise a concentrate reservoir having a first portion and a second portion, which is attached to the steam chamber via an inflow path. The second portion may consist at least partially of an obstruction. The obstruction may extend laterally to the first portion within the concentrate reservoir, and the concentrate reservoir may be divided into an unshielded section and a shielded section. The steam distillation apparatus may further comprise a float assembly located within the shielded section. The float assembly may be displaceable over a displacement range including a point at the same height as all steam chamber liquid levels within an expected range of steam chamber liquid levels. The steam distillation apparatus may further comprise a sensor configured to monitor the position of the float assembly and to output a data signal indicating the liquid level in the steam chamber based on the position of the float assembly. The steam distillation apparatus may further include a compressor having an inlet for establishing fluid communication with a steam chamber and an outlet for establishing fluid communication with a condenser.

[0010] In some embodiments, the sensor may be an encoder. In some embodiments, the float assembly may include at least one magnet. In some embodiments, the sensor may be a Hall effect sensor. In some embodiments, the float assembly may be mounted on a pivot. In some embodiments, the float assembly may be displaceable about the pivot. In some embodiments, the obstruction may extend into the concentrate reservoir at an angle substantially perpendicular to the first portion of the inflow path. In some embodiments, the steam distillation apparatus may further include a vent path extending from the concentrate reservoir into the steam chamber. In some embodiments, the vent path may extend parallel to and above the first portion of the inflow path. In some embodiments, the vent path may have a smaller cross-sectional area than that of the first portion of the inflow path.

[0011] According to another embodiment of the present disclosure, the steam distillation apparatus may include a reservoir having a source fluid input. The steam distillation apparatus may further include an evaporator having a first side that is in fluid communication with the source fluid input via the reservoir, and a second side that is in fluid communication with a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into low-pressure steam and concentrate as the source fluid progresses toward the steam chamber. The steam distillation apparatus may further include a concentrate reservoir mounted to and laterally to the steam chamber. The concentrate reservoir may include a concentrate level sensor configured to monitor the level of concentrate in the steam chamber and generate a data signal indicating the level of concentrate. The steam distillation apparatus may further include a compressor having a low-pressure steam inlet that establishes fluid communication with the steam chamber, and a high-pressure steam outlet that establishes fluid communication with a condenser via a condenser inlet. The steam distillation apparatus may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with multiple external surfaces of the evaporator. The condenser may include a condensing section and a condensate storage or reservoir section. The steam distillation apparatus may further include an auxiliary condensate reservoir in fluid communication with the condensate storage section. The auxiliary condensate reservoir may be mounted on the condenser adjacent to the storage surface of the storage section and may include a condensate level sensor configured to monitor the level of condensate in the storage section and generate a data signal indicating the percentage that the storage section is filled with condensate.

[0012] In some embodiments, the storage portion may have a volume of less than 10 liters. In some embodiments, the multiple external surfaces may be the external surfaces of multiple evaporator tubes contained within the evaporator. In some embodiments, the multiple external surfaces may be the external surfaces of 90 to 100 evaporator tubes contained within the evaporator. In some embodiments, the multiple external surfaces may be the external surfaces of 70 to 80 evaporator tubes contained within the evaporator. In some embodiments, the condensate level sensor may include a float assembly that is pivotally mounted. In some embodiments, the float assembly may be displaceable about the pivot over a displacement range that includes points at the same height as the range of levels defined by the accumulation portion. In some embodiments, the concentrate level sensor may include a float assembly that is located within a shielded section of the concentrate reservoir, separated from the unshielded portion of the concentrate reservoir by a barrier. In some embodiments, the float assembly may be pivotally mounted and displaceable about the pivot over a displacement range that includes points at the same height as all steam chamber concentrate levels within the expected range of steam chamber liquid levels. In some embodiments, the concentrate level sensor may be located within a sleeve that forms a barrier.

[0013] According to another embodiment of the present disclosure, a concentrate level control system for a fluid vapor distillation apparatus may include a source fluid input that selectively fluidizes a source fluid reservoir via at least one input valve. The concentrate level control system may further include an evaporator that fluidizes the source input and fluidizes a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into a steam flow and a concentrate flow as the source fluid progresses toward the steam chamber. The concentrate level control system may further include a concentrate reservoir that is attached to the steam chamber via an inlet path and positioned laterally thereto, and selectively communicates with a concentrate destination via an outlet valve. The concentrate level control system may further include a concentrate level sensor configured to generate a data signal indicating the concentrate level in the steam chamber. The concentrate level control system may further include a controller configured to carefully modify the concentrate level in a predetermined pattern by controlling the operation of at least one inlet valve via a fluid input control loop and by analyzing the data signal. The controller may also be configured to activate the outlet valve to a closed state when the data signal indicating the concentrate level falls below a first threshold, and to activate the outlet valve to an open state when the concentrate level exceeds a second threshold.

[0014] In some embodiments, a predetermined pattern may generate a sawtooth waveform when the concentrate level is plotted over time. In some embodiments, the period of the sawtooth waveform may depend, at least in part, on a fluid input command from a fluid input control loop. In some embodiments, the fluid input command may be determined based on a predefined target concentrate production rate. In some embodiments, the controller may be configured to operate in multiple operating states, and the predefined target concentrate production rate may be state-specific. In some embodiments, the controller may analyze the data signal on a predetermined basis. In some embodiments, the concentrate level may be assigned a predefined expected range, and a first threshold may be less than or equal to 50% of the maximum level of the expected range. In some embodiments, the first threshold may be 40% to 50% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and a second threshold may be greater than or equal to 50% of the maximum level of the expected range. In some embodiments, the second threshold may be 50% to 60% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and the first threshold may be less than or equal to 40% of the maximum level of the expected range. In some embodiments, the first threshold may be 40% to 30% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and the second threshold may be greater than or equal to 45% of the maximum level of the expected range. In some embodiments, the second threshold may be 45% to 55% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and the first and second thresholds may be defined as percentages of the maximum level of the expected range. The second threshold may be 4 to 20 percent above the first threshold. In some embodiments, the concentrate destination is a mixing tank.

[0015] According to another embodiment of the present disclosure, a method for controlling the level of concentrate in a distillation device and matching the fluid flow within the distillation device may include introducing a source fluid into the distillation device through at least one inlet valve. The method may further include evaporating at least a portion of the source fluid as it proceeds toward the steam chamber to generate steam and concentrate. The method may further include collecting the concentrate in a concentrate reservoir, which is attached to and positioned laterally to the steam chamber, via an inlet path. The method may further include providing a data signal indicating the concentrate level in the steam chamber from a concentrate level sensor located in the concentrate reservoir. The method may further include modifying the concentrate level in a predetermined pattern by using a controller to control the operation of at least one inlet valve via a fluid input control loop, analyzing the data signal, and operating the outlet valve of the concentrate reservoir to a closed state when the data signal indicating the concentrate level falls below a first threshold, and to an open state when the concentrate level exceeds a second threshold.

[0016] In some embodiments, modifying the concentrate level may include modifying the concentrate level to generate a sawtooth waveform when the concentrate level is plotted over time. In some embodiments, analyzing the data signal may include analyzing the data signal on a predetermined basis. In some embodiments, the method may further include assigning a predefined expected range to the concentrate level and setting a first threshold so that it is less than or equal to 50% of the maximum level of the expected range. In some embodiments, setting the first threshold may include setting the threshold to 40% to 50% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range to the concentrate level and setting a second threshold so that it is greater than or equal to 50% of the maximum level of the expected range. In some embodiments, setting the second threshold may include setting the second threshold to 50% to 60% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range to the concentrate level and setting a first threshold so that it is less than or equal to 40% of the maximum level of the expected range. In some embodiments, setting the first threshold may include setting the threshold to 40% to 30% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range of concentrate levels and setting a second threshold to be above or equal to 45% of the maximum level of the expected range. In some embodiments, setting the second threshold may include setting the second threshold to 45% to 55% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range of concentrate levels and setting the first and second thresholds as percentages of the maximum level of the expected range, where the second threshold is a 4 to 20 percent point above the first threshold.

[0017] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation device to a desired temperature may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator that fluidizes the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The system may further include a condenser that fluidizes the compressor and is configured to convert the pressurized vapor from the compressor into a condensate. The system may further include a condensate flow path and a concentrated flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir. The heat exchange portion may be downstream of the source fluid input valves. The system may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. A condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The system may further include a controller configured to operate a set of input source valves based on a first control loop that controls the total open time for all input source valves in a set of input source valves, and a second control loop that receives data signals and a requested temperature, divides the total open time for all input source valves, and adjusts the condensate temperature to the requested temperature.

[0018] In some embodiments, the heat exchange portions of the source fluid flow paths in the first and second heat exchangers may be arranged countercurrently to their respective condensate and concentrate flow paths. In some embodiments, the system may further include a destination device that fluidically communicates with the condensate flow path via a point-of-use valve. In some embodiments, the required temperature may be generated by the destination device. In some embodiments, the destination device may be a medical system. In some embodiments, the medical system may be configured to mix at least one dialysate solution. In some embodiments, the destination device may be a dialysis machine. In some embodiments, the destination device may be a hemodialysis machine. In some embodiments, at least one of the first and second control loops may be a PID control loop. In some embodiments, the gain of at least one of the terms in the PID control loop may be zero. In some embodiments, a feedforward term may be combined with the output of the second control loop. In some embodiments, the feedforward term may be based on an estimated division of the total open time. In some embodiments, the system may further include a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level in the distillation device. A first control loop may be configured to receive the target concentrate level and the current concentrate level data signal as inputs to the first control loop. In some embodiments, the controller may further be configured to adjust the heater duty cycle at least in part based on the total open time for all input source valves of a set of input source valves. In some embodiments, the controller may be configured to increase the heater duty cycle when the open time for all input source valves of a set of input source valves is increased.

[0019] According to another embodiment of the present disclosure, a method for controlling the temperature of the product process flow of a distillation device to a required temperature may include controlling the flow of the source fluid input to the distillation device by using a controller to actuate a set of source fluid valves. The method may further include converting at least a portion of the source fluid input into vapor and concentrate in an evaporator. The method may further include condensing the vapor into condensate in a condenser. The method may further include removing at least a portion of the condensate and concentrate from the distillation device through separate condensate and concentrate flow paths. The method may further include exchanging heat between the source fluid flow and the condensate flow path in a first heat exchanger and exchanging heat between the source fluid flow and the concentrate flow path in a second heat exchanger. The method may further include providing a condensate temperature data signal to the controller from a temperature sensor on the condensate flow path located downstream of the first heat exchanger. The method may further include using a controller to determine the total open state time for each set of fluid input valves based on a first control loop, and to divide the total open state time between sets of fluid input valves based on a second control loop that receives a temperature data signal and a required temperature.

[0020] In some embodiments, the method may further include flowing the condensate and concentrate through a condensate and concentrate flow path in the counter-flow direction with respect to the flow of the source fluid. In some embodiments, the method may further include providing the condensate to a destination device by activating a point-of-use valve downstream of a temperature sensor. In some embodiments, the required temperature may be generated by the destination device. In some embodiments, the destination device may be a medical system. In some embodiments, the method may further include mixing dialysate using the condensate. In some embodiments, the destination device may be a dialysis machine. In some embodiments, the destination device may be a hemodialysis machine. In some embodiments, at least one of the first and second control loops may be a PID control loop. In some embodiments, the method may further include setting at least one of the gains of the PID control loop to zero. In some embodiments, the method may further include combining a feedforward term with the output of the second control loop. In some embodiments, the method may further include determining the feedforward term based on an estimated division of the total open state time. In some embodiments, the method further includes inputting the current concentrate level and target concentrate level, provided by a concentrate level sensor, into a first control loop. In some embodiments, the method may further include, at least in part, adjusting the heater duty cycle based on the total open state time for all input source valves of a set of input source valves. In some embodiments, adjusting the heater duty cycle may include increasing the heater duty cycle when the open state time for all input source valves of a set of input source valves is increased.

[0021] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of a product process stream of a distillation device may include a first source fluid input and a second fluid source input that are selectively in fluid communication with a source fluid reservoir via a set of first fluid input valves and a set of second fluid input valves, respectively. The system may further include an evaporator in fluid communication with the first and second source fluid inputs and in fluid communication with a compressor. The evaporator may have a heating element for converting the source fluid from the first and second source fluid inputs into a vapor stream and a concentrated stream as the source fluid progresses towards the compressor. The system may further include a condenser in fluid communication with the compressor. The condenser may be configured to convert the pressurized vapor from the compressor into a condensate. The system may further include a condensate flow path and a concentrated flow path that include individual first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of a source fluid flow path from the source fluid reservoir, and the heat exchange portion may be downstream of the set of source fluid input valves. The system may further include a condensate temperature sensor configured to generate a data signal indicative of the condensate temperature. The condensate temperature sensor may be disposed on the condensate flow path downstream of the first heat exchanger. The system may further be configured to operate a set of first input source valves based on a first control loop that controls the total open state time for all input source valves of the set of first input source valves, and a second control loop that receives the data signal and a required temperature, divides the total open state time among all of the input source valves of the set of first input source valves, and adjusts the condensate temperature to the required temperature. The controller may be configured to monitor at least one process variable and operate a set of second input source valves when one of the at least one process variables is outside a predefined threshold.

[0022] In some embodiments, the first set of fluid input valves may include at least one valve not included in the second set of fluid input valves. In some embodiments, one of the first and second source fluid inputs may be temperature controlled. In some embodiments, the second source fluid input may be temperature controlled. In some embodiments, the second source fluid input may be a high-temperature fluid input. In some embodiments, at least one process variable monitored by the controller may be the heating element duty cycle. In some embodiments, at least one process variable monitored by the controller may be the output of the first control loop. In some embodiments, at least one process variable may be the compressor speed. In some embodiments, the heat exchange portion of the source fluid flow path may be a common flow path for the fluids from the first and second source fluid inputs.

[0023] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation device to a required temperature may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator that selectively fluidizes the source fluid input and fluidizes a compressor via a bypass valve. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrated stream as the source fluid progresses towards the compressor. The system may further include a condenser configured to convert the pressurized vapor from the compressor into condensate and in fluid communication with the compressor. The system may further include a condensate flow path and a concentrated flow path including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, and the heat exchange portion is downstream of the source fluid input valve. The system may further include a condensate temperature sensor configured to generate a data signal indicative of the condensate temperature. The condensate temperature sensor may be disposed on the condensate flow path downstream of the first heat exchanger. The system may further include a first control loop that controls the total open state time for all of the input source valves of a set of input source valves, and a second control loop that receives the data signal and the required temperature, divides the total open state time among all of the input source valves, and adjusts the condensate temperature to the required temperature, and a controller configured to operate the set of input source valves based on the first and second control loops. The bypass valve may be disposed within the source fluid flow path downstream of the heat exchange portion of the source fluid flow path. The bypass valve may have a bypass valve state that directs fluid from the source reservoir to the drain destination. The controller may be configured to operate the bypass valve to the bypass valve state when the controller determines that at least one process variable is outside of a predetermined threshold.

[0024] In some embodiments, at least one process variable may be the relationship between the condensate temperature and the source fluid temperature provided by the source fluid temperature sensor. In some embodiments, at least one process variable may be the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, at least one process variable may be defined at least partially by the condensate temperature and the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, the controller may modify the duty cycle of at least one of the input source valves when the bypass valve is in the bypass valve state. In some embodiments, the controller may increase the duty cycle of at least one of the input source valves when the bypass valve is in the bypass valve state. In some embodiments, the controller may modify the duty cycle of at least one of the input source valves to 90-100% when the bypass valve is in the bypass valve state. In some embodiments, one of the at least one of the input source valves may be a valve that controls the flow of source fluid through the heat exchange portion of the first heat exchanger.

[0025] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation system to a required temperature may include a source fluid input that selectively communicates with a source fluid reservoir via a set of fluid input valves. The system may further include a distillation device configured to generate concentrated and condensed flow. The system may further include a condensate flow path and a concentrate flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, the heat exchange portion being downstream of the source fluid input valve. The system may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. The condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The system may further include a point-of-use device that selectively communicates with the condensate flow path. The point-of-use device may have an outlet flow path for the output fluid generated by the point-of-use device. The output flow path may have a third heat exchanger, which includes a heat exchange portion of a branch in the source fluid flow path. The system may further include a controller configured to actuate a set of input source valves based on a first control loop and a second control loop, and based on at least one process variable, which control the fluid flow of the source fluid through the heat exchange portions of the first and second heat exchangers. The controller may actuate a branch valve to a branch in the source fluid flow path when at least one process variable is outside a predetermined threshold.

[0026] In some embodiments, at least one process variable may be the relationship between the condensate temperature and the source fluid temperature provided by a source fluid temperature sensor. In some embodiments, at least one process variable may be the source fluid temperature sensed by a source fluid temperature sensor. In some embodiments, at least one process variable may be defined at least partially by the condensate temperature and the source fluid temperature sensed by a source fluid temperature sensor. In some embodiments, the point-of-use device may be a medical device. In some embodiments, the point-of-use device is a dialysis machine. In some embodiments, the point-of-use device is a hemodialysis machine or a peritoneal dialysis machine. In some embodiments, the point-of-use device may be a dialysate mixing device. In some embodiments, the branching of the source fluid flow path may be located upstream of the heat exchange portion of the source fluid flow path in the first and second heat exchangers. In some embodiments, the output fluid may be dialysate wastewater.

[0027] According to another embodiment of the present disclosure, a condensate accumulation rate control system for controlling the rate of condensate accumulation in a distillation device may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator that fluidizes the source input and fluidizes a compressor having an impeller operably coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The system may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator. The system may further include a condensate level sensor configured to sense the current level of condensate in the condenser. The system may further include at least one controller configured to control the rotational speed of the impeller by periodically generating impeller motor commands based on the last motor speed command, a motor speed target, and a speed command increment limit. The motor speed target may be calculated by a control loop that receives the current condensate level and a desired condensate level as control loop inputs.

[0028] In some embodiments, the speed command increment limit may be ≤10 rpm / second. In some embodiments, the speed command increment limit may be ≤5 rpm / second. In some embodiments, the controller may be configured to compare an impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and adjust the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold when the impeller motor command is below the minimum command speed threshold, and equal to the maximum command speed threshold when the impeller motor command is above the maximum command speed threshold. In some embodiments, the minimum command speed threshold is 1,500 to 2,500 rpm. In some embodiments, the maximum command speed threshold is calculated each time a motor speed command is generated. In some embodiments, the maximum command speed threshold may be calculated based on at least one motor parameter. In some embodiments, the system may further include a motor temperature sensor configured to output a temperature data signal indicating the temperature of the impeller motor, and a power factor correction current monitoring circuit configured to output a PFC data signal indicating the current power factor correction current, and the maximum command speed threshold is calculated based on the temperature data signal and the PFC data signal. In some embodiments, the maximum command speed is set with a predetermined value as the upper limit. In some embodiments, the predetermined value may be 4,500 to 6,500 rpm. In some embodiments, the predetermined value may be 5,000 rpm. In some embodiments, the predetermined value may be about 2.5 times greater than the minimum command speed threshold.

[0029] According to another embodiment of the present disclosure, a method for controlling the rate of condensate accumulation in a distillation device may include providing a source fluid input to the distillation device. The method may further include evaporating at least a portion of the source fluid input into low-pressure vapor in an evaporator. The method may further include compressing low-pressure steam to high-pressure steam via an impeller. The method may further include condensing the high-pressure steam into condensate in a condenser and transferring heat from the high-pressure steam to an evaporator. The method may further include providing the controller with the level of condensate in the condenser, as sensed by a condensate level sensor. The method may further include using the controller to calculate a motor speed target based on the condensate level and a desired condensate level. The method may further include using the controller to control the rotational speed of the impeller by periodically generating impeller motor commands based on the last motor speed command, motor speed target, and speed command increment limit.

[0030] In some embodiments, the speed command increment limit is ≤10 rpm / sec. In some embodiments, the speed command increment limit is ≤5 rpm / sec. In some embodiments, the method may further include using a controller to compare an impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and adjusting the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold when the impeller motor command is below the minimum command speed threshold, and equal to the maximum command speed threshold when the impeller motor command is above the maximum command speed threshold. In some embodiments, the minimum command speed threshold may be 1,500 to 2,500 rpm. In some embodiments, the minimum command speed threshold may be 2,000 rpm. In some embodiments, the method may further include calculating the maximum command speed threshold each time a motor speed command is generated. In some embodiments, calculating the maximum command speed threshold may include calculating the maximum command speed threshold based on at least one motor parameter. In some embodiments, the method may further include providing the controller with a temperature data signal indicating the motor temperature from a motor temperature sensor and a power factor correction data signal indicating the current power factor correction current from a monitoring circuit. In some embodiments, the method may further include calculating a maximum command speed threshold based on the temperature data signal and the power factor correction data signal. In some embodiments, the method may further include setting a predetermined value as an upper limit for the maximum command speed threshold. In some embodiments, the predetermined value may be 4,500 to 6,500 rpm. In some embodiments, the predetermined value may be 5,000 rpm. In some embodiments, the predetermined value may be 2.5 times greater than or approximately that of the minimum command speed threshold.

[0031] According to one embodiment of the present disclosure, a fluid vapor distillation apparatus having first and second separable sections may include a source inlet that selectively communicates with a fluid source via at least one valve. The apparatus may further include a reservoir downstream of the source inlet. The apparatus may further include an evaporator having a plurality of tubes that communicate with the reservoir. The apparatus may further include a steam chamber coupled to the evaporator and communicating with a compressor. The apparatus may further include a condenser that communicates with the outlet of the compressor. The condenser may surround a plurality of tubes. The apparatus may further include a support plate that is rotatably coupled to a pivot and attached to the first section. The apparatus may further include a housing coupled to the second section via at least one mounting section. The first and second sections may be held together in a first state via one or more fasteners, and may be disconnected from each other in a second state in which the first section is rotatable about a pivot.

[0032] In some embodiments, at least one mounting section may be an isolated mounting section. In some embodiments, the first section may include a reservoir, an evaporator, and a condenser. In some embodiments, the second section may include a steam chamber and a condenser. In some embodiments, the pivot may include a biasing member. In some embodiments, the biasing member may be in a relaxed state when the first and second sections are in a first state, and in a compressed state when the first and second sections are in a second state. In some embodiments, the biasing member may have a relaxed state and an energy storage state. The support plate may have a displacement path between a first position when the biasing member is in a relaxed state and a second position when the biasing member is in an energy storage state. In some embodiments, the displacement path may be a linear displacement path. In some embodiments, the displacement path may be parallel to the axis of the pivot. In some embodiments, the biasing member may be a gas spring.

[0033] According to another embodiment of the present disclosure, the distillation apparatus may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The apparatus may further include an evaporator that fluidizes the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The apparatus may further include a condenser that fluidizes the compressor and is configured to convert the pressurized vapor from the compressor into a condensate. The apparatus may further include a condensate flow path and a concentrated flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir. The heat exchange portion may be downstream of the source fluid input valves. The apparatus may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. The condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The device may further include a controller configured to actuate a set of input source valves based on a first multimodal control loop that generates a certain number of provisional total open state commands for all input source valves in the set of input source valves. The controller may be configured to actuate a set of input source valves based on a slider that generates a single total open state command from a number of provisional commands. The controller may be configured to actuate a set of input source valves based on a second control loop that receives data signals and temperature setpoints, distributes total open state commands among all input source valves, and adjusts the condensate temperature to the temperature setpoint.

[0034] In some embodiments, the heat exchange portions of the source fluid flow paths in the first and second heat exchangers may be arranged countercurrent to their respective condensate and concentrate flow paths. In some embodiments, the controller may be configured to operate in multiple operating states, and the temperature setpoint may be state-dependent. In some embodiments, the device further comprises a destination device that fluidically communicates with the condensate flow path via a point-of-use valve. In some embodiments, the destination device may be a medical system. In some embodiments, the medical system may be configured to mix at least one dialysate solution. In some embodiments, the destination device may be a dialysis machine. In some embodiments, the destination device may be a hemodialysis machine. In some embodiments, at least one of the first multimodal control loop and the second control loop may include a PID control loop. In some embodiments, the gain of at least one of the terms in the PID control loop may be zero. In some embodiments, the number of provisional total open state commands may be regulated by the output of at least one regulator control loop. In some embodiments, the distillation device may further comprise a water reservoir. The water reservoir may be located between the source input and the evaporator. One of at least one of the controller control loops may be configured to produce output based on a target reservoir temperature and the current reservoir temperature measured by a reservoir temperature sensor configured to generate a data signal representing the temperature of the fluid in the reservoir. In some embodiments, one of at least one of the controller control loops may be configured to produce output based on a target vapor temperature and the current vapor temperature measured by a vapor temperature sensor configured to generate a data signal representing the temperature of the vapor flow. In some embodiments, the device may further include a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level in the distillation device. The controller may be configured to determine the current blowdown rate from the concentrate level data signal.The first multimodal control loop may be configured to receive target blowdown rate and current blowdown rate data signals as inputs. In some embodiments, at least one of the provisional total open state commands may be a first production temperature state command, and at least one of the provisional total open state commands may be a second production temperature state command. In some embodiments, the device may further include an evaporator level sensor configured to output an evaporator data signal. The controller may be configured, at least in part, to generate at least one of the provisional total open state commands based on the inputs of the target evaporator sensor level and the evaporator data signal. In some embodiments, the target evaporator sensor level and the evaporator data signal may be input to a differential controller. In some embodiments, the differential controller may be a PID controller having a D-term gain that is at least one order of magnitude higher than the P and I terms.

[0035] According to another embodiment of the present disclosure, the steam distillation apparatus may include a reservoir having a source fluid input. The apparatus may further include an evaporator having a first side that is in fluid communication with the source fluid input via the reservoir, and a second side that is in fluid communication with a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into low-pressure steam and concentrate. A non-uniform liquid level may exist in the evaporator during operation. The apparatus may further include an evaporator reservoir positioned laterally to the evaporator and in fluid communication with it via the reservoir. The evaporator reservoir may include a level sensor configured to monitor the level of the water column in the evaporator reservoir and generate a data signal indicating the level of the water column. The apparatus may further include a compressor having a low-pressure steam inlet that establishes fluid communication with a steam chamber and a high-pressure steam outlet that establishes fluid communication with a condenser via a condenser inlet. The apparatus may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with multiple external surfaces of the evaporator. The condenser may include a condensing section and a condensate accumulation section. The apparatus may further include a processor, which is configured in part to actuate a set of input source valves to the source fluid input based on data signals.

[0036] In some embodiments, the level sensor may include a displaceable member that is displaceable over a displacement range smaller than the height of the evaporator reservoir. In some embodiments, the level sensor may include a displaceable member that is displaceable over a displacement range extending from a first end portion of the evaporator reservoir to at least the midpoint of the evaporator reservoir. The displacement range may be a distance of less than 70% of the height of the evaporator reservoir. In some embodiments, the first end may be the furthest end of the evaporator reservoir from the water reservoir. In some embodiments, the evaporator reservoir may communicate with the steam chamber via a ventilation path extending from the first end portion of the evaporator reservoir. In some embodiments, the ventilation path may extend from the evaporator reservoir to a concentrate reservoir attached to and laterally positioned relative to the steam chamber. In some embodiments, the height of the evaporator reservoir may exceed the height of the evaporator. In some embodiments, the processor may be configured to determine the total open state time for a set of input source valves based in part on the current water column level determined via analysis of the target water column level and data signals. In some embodiments, the processor may be configured to determine the total open state time for a set of input source valves based in part on the output of a PID controller that receives a target water column level and the current water column level as inputs. In some embodiments, the gain for at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain for the D term of the PID controller may be at least one order of magnitude higher than the gains for the P and I terms of the PID controller. In some embodiments, the gain for the D term of the PID controller may be two orders of magnitude higher than the gains for the P and I terms of the PID controller. In some embodiments, the processor may be configured to determine the total open state time based in part on a target blowdown rate and the current blowdown rate, such as indicated by a blowdown level data signal produced by a blowdown level sensor in a blowdown reservoir mounted in the steam chamber.In some embodiments, the processor may be configured to determine a total open state command, in part, based on the output of at least one controller control loop. In some embodiments, one of the at least one controller control loop may be configured to produce an output based on a target reservoir temperature and the current reservoir temperature measured by a reservoir temperature sensor, which is configured to generate a data signal representing the temperature of the fluid in the reservoir. In some embodiments, one of the at least one controller control loop may be configured to produce an output based on a target steam temperature and the current steam temperature measured by a steam temperature sensor, which is configured to generate a data signal representing the temperature of the steam flow. In some embodiments, the controller may be configured to modify a total open state command for a set of input source valves in response to a change in the water column level indicated by a data signal. In some embodiments, the controller may be configured to modify a total open state command for a set of input source valves in proportion to the rate of change in the water column, as indicated by a data signal.

[0037] According to another embodiment of the present disclosure, a method for controlling the flow of a source fluid into a distillation device may include establishing a non-uniform liquid level within the evaporator of the distillation device. The method may further include using a first level sensor to sense the liquid column level in an evaporator reservoir, which is in fluid communication with the evaporator and positioned at the same height as the evaporator. The method may further include using a second level sensor to sense the concentrate level in a concentrate reservoir, which is in fluid communication with the evaporator. The method may further include using a processor to generate source inlet valve open time commands, at least in part, based on the concentrate level and the target concentrate accumulation rate, as well as the delta between the liquid column level and the target liquid column level. The method may further include commanding a number of source inlet valves to open based on the source inlet valve open time commands.

[0038] In some embodiments, sensing the liquid column level may include displacing a displaceable member over a displacement range smaller than the height of the evaporator reservoir. In some embodiments, sensing the liquid column level may include displacing a displaceable member over a displacement range extending from a first end portion of the evaporator reservoir to at least the midpoint of the evaporator reservoir. The displacement range may be a distance of less than 70% of the height of the evaporator reservoir. In some embodiments, the first end may be the furthest end of the evaporator reservoir of the water reservoir of the distillation device. In some embodiments, the method may further include venting from the evaporator reservoir through a vent path into the vapor chamber of the distillation device located above the evaporator. In some embodiments, the vent path may extend from the evaporator reservoir to a concentrate reservoir attached to and laterally positioned to the vapor chamber. In some embodiments, generating a source inlet valve open time command may include inputting a delta to a PID controller. In some embodiments, the gain for at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain for the D term of the PID controller may be at least one order of magnitude higher than the gains for the P and I terms of the PID controller. In some embodiments, the gain for the D term of the PID controller may exceed the gains for the P and I terms of the PID controller by more than two orders of magnitude. In some embodiments, generating a source inlet valve open time command may include determining the current concentrate accumulation rate from the concentrate level and calculating the delta between the target concentrate rate and the current concentrate accumulation rate. In some embodiments, generating a source inlet valve open time command may include generating an output for at least one regulator control loop. In some embodiments, the method may further include sensing the current reservoir temperature using a reservoir temperature sensor, and generating an output for at least one regulator control loop may include producing an output based on the target reservoir temperature and the current reservoir temperature. In some embodiments, the method may further include sensing the temperature of the vapor flow in the distillation device using a vapor temperature sensor. In some embodiments, generating an output for at least one regulator controller may include producing an output based on the target vapor temperature and the current vapor temperature. In some embodiments, the method may further include modifying the source inlet valve open time command in response to a change in the liquid column level. In some embodiments, the method may further include modifying the source inlet valve opening time command in proportion to the rate of change of the liquid column level.

[0039] According to another embodiment of the present disclosure, the fluid vapor distillation apparatus may comprise at least one controller. The apparatus may further comprise a source inlet that selectively communicates with a fluid source via at least one valve. The apparatus may further comprise an evaporator that communicates with the source inlet. The apparatus may further comprise a steam chamber coupled to the evaporator and communicating with a compressor. The external surface of the steam chamber may form part of the inlet flow path to the compressor and part of the outlet flow path to the compressor outlet. The apparatus may further comprise a concentrate reservoir. The concentrate reservoir may be mounted to the steam chamber via an inlet path and positioned laterally to the steam chamber such that at least a portion of the concentrate reservoir is at the same height as the steam chamber. The apparatus may further include a condenser that is in fluid communication with the compressor outlet via a linear flow path. The linear flow path may include a condenser inlet fixed to a sheet, having a first surface defining a portion of the steam chamber and an opposing surface defining a portion of the condenser. The apparatus may further include a product process flow reservoir coupled to the condenser by a product reservoir inlet and positioned laterally to the condenser, such that at least a portion of the product process flow reservoir is at the same height as the condenser.

[0040] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a wall extending into the concentrate reservoir at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate reservoir and divide the concentrate reservoir into a first part and a second shielded part. In some embodiments, the obstruction may include at least one vent port. In some embodiments, the product reservoir inlet may be adjacent to the product accumulation surface of the condenser. In some embodiments, the compressor may be driven by a motor located in a receiving well that is partially fitted into the side of the steam chamber. In some embodiments, the compressor may include an impeller that extends laterally relative to the steam chamber and rotates about an axis parallel to the longitudinal axis of the steam chamber.

[0041] According to another embodiment of the present disclosure, the distillation apparatus may include a source fluid input that selectively communicates with a source via a set of fluid input valves. The apparatus may further include an evaporator that communicates with a compressor having an impeller that is fluidly connected to the source input and operably coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid progresses toward the compressor. The device may further include a condenser that is in heat transfer relationship with multiple external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the multiple external surfaces of the evaporator. The device may further include a concentrate level sensor configured to sense the current level of concentrate in a concentrate reservoir, which has an inflow path and a long axis extending parallel to the evaporator, and is located above the evaporator. The device may further include at least one controller configured to control the rotational speed of the impeller in the low-temperature and high-temperature distillate production states by periodically generating an impeller motor command based on a nominal low-temperature distillate production speed command in the low-temperature distillate production state and a nominal high-temperature distillate production speed command in the high-temperature distillate production state. The nominal low-temperature distillate production speed command may be a motor speed command that is faster than the nominal high-temperature distillate production speed command.

[0042] In some embodiments, adjustments to the impeller motor command may be made based on a data signal from a concentrate level sensor indicating the level of concentrate in the concentrate reservoir. In some embodiments, the adjustment may be limited by an impeller motor command increment limit. In some embodiments, the impeller motor command increment limit may be ≤10 rpm / sec. In some embodiments, the impeller motor command increment limit may be ≤5 rpm / sec. In some embodiments, the impeller motor command may be decremented when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds a first threshold. In some embodiments, the first threshold may be defined as the concentrate level when the concentrate reservoir is at a predefined fill value of 65-80%. In some embodiments, the impeller motor command may be held below a previously commanded impeller motor command value when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds the first threshold. In some embodiments, the first threshold may be defined as the concentrate level when the concentrate reservoir is at a predefined fill value of 65-80%. In some embodiments, the impeller motor command may be incremented when the data signal indicates that the concentrate level in the concentrate reservoir exceeds the second threshold. In some embodiments, the high-temperature distillate production nominal speed command may be a calibration value defined during production. In some embodiments, the high-temperature distillate production nominal speed command may be less than 80% of the low-temperature distillate production nominal speed command and greater than 45% of the low-temperature distillate production nominal speed command. In some embodiments, the low-temperature distillate production nominal speed command may be 4,500 rpm. In some embodiments, the low-temperature distillate production nominal speed command may be 5,000 rpm.

[0043] According to another embodiment of the present disclosure, a method for controlling the compressor of a distillation device may include opening at least one fluid inlet valve to deliver source fluid from a fluid source into the reservoir of the distillation device. The method may further include converting the source fluid into a concentrated flow and a vapor flow in the evaporator. The method may further include using a processor to determine a state-specific compressor speed command. The compressor speed command may be based on a nominal low-temperature distillate production speed command in a low-temperature distillate production state and on a nominal high-temperature distillate production speed command in a high-temperature distillate production state. The nominal low-temperature distillate production speed command may be a motor speed command that is faster than the nominal high-temperature distillate production speed command. The method may further include using a processor to generate a final command speed based on the compressor speed command. The method may further include using a processor to command the rotation of the compressor impeller at the final command speed. The method may further include compressing the vapor flow through the compressor. The method may further include condensing the vapor flow into a condensate as the vapor flow condenses and transferring heat to the evaporator.

[0044] In some embodiments, the method may further include sensing the level of concentrate in a concentrate reservoir that is in fluid communication with the evaporator using a level sensor. In some embodiments, generating the final command speed may include determining an adjustment to the compressor speed command based on the concentrate level. In some embodiments, determining an adjustment may include decrementing the compressor speed command when the concentrate level exceeds a first threshold. In some embodiments, the first threshold may be defined as the concentrate level when the concentrate reservoir is at a predefined fill value of 65-80%. In some embodiments, determining an adjustment may include maintaining the final command speed at or below a previously commanded final command speed when the concentrate level exceeds the first threshold. In some embodiments, determining an adjustment may include decrementing the compressor speed command when the concentrate level exceeds a second threshold. In some embodiments, generating the final command speed may include determining an adjustment to the compressor speed command. In some embodiments, the adjustment may be limited by an increment limit. In some embodiments, the increment limit may be ≤10 rpm / sec. In some embodiments, the increment limit may be ≤5 rpm / second. In some embodiments, the nominal high-temperature distillate production rate command may be a calibration value defined during production. In some embodiments, the nominal high-temperature distillate production rate command may be less than 80% of the nominal low-temperature distillate production rate command and greater than 70% of the nominal low-temperature distillate production rate command. In some embodiments, the nominal low-temperature distillate production rate command may be 4,500 rpm.

[0045] According to another embodiment of the present disclosure, the distillation apparatus may include a reservoir that selectively communicates with a source via a set of fluid input valves. The apparatus may further include in the reservoir at least one heating element and at least one reservoir temperature sensor. The reservoir temperature sensor may be configured to generate a reservoir temperature data signal. The apparatus may further include an evaporator having a first side that communicates with the reservoir and a second side that communicates with a compressor having an impeller operably coupled to an impeller motor. The evaporator may be configured to convert a source fluid from a source fluid input into a vapor flow and concentrate. The apparatus may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with multiple external surfaces of the evaporator. The device may further include a concentrate level sensor configured to sense the current level of concentrate in a concentrate reservoir, which has an inflow path and a long axis extending parallel to the evaporator, and is located above the evaporator. The device may further include a vapor temperature sensor located in the vapor flow path and configured to generate a vapor temperature data signal. The device may further include at least one controller configured to determine a duty cycle command for at least one heating element. The duty cycle command may be at least in part based on a target temperature for the vapor flow, a vapor temperature data signal, a reservoir temperature data signal, and a total source open command for a set of fluid inlet valves.

[0046] In some embodiments, the target temperature of the vapor flow may be 108°C. In some embodiments, the controller may be configured to adjust the duty cycle command to match at least one limit. In some embodiments, the limit may be a maximum power consumption limit. In some embodiments, the controller may be configured to adjust the duty cycle command at least partially based on the compressor's power consumption. In some embodiments, the controller may be configured to determine the compressor's power consumption and calculate the limit for the duty cycle command by subtracting the compressor's power consumption from a predefined power value. In some embodiments, the predefined power value may be defined as the maximum total power for the system. In some embodiments, the duty cycle command may be limited to a pre-determined maximum duty cycle. In some embodiments, the predefined maximum duty cycle may be 90% duty cycle or less. In some embodiments, the target temperature of the vapor flow may be state-specific. In some embodiments, the target temperature in the low-temperature distillate production state may be higher than the target temperature in the high-temperature distillate production state. In some embodiments, the target temperature of the vapor flow in the first state may be 108°C, and the target temperature of the vapor flow in the second state may be 104°C. In some embodiments, the target temperature in the first state may be 4°C higher than the target temperature in the second state. In some embodiments, the target temperature in the first state may be at least 95% of the target temperature in the second state, but less than the target temperature in the second state. In some embodiments, the controller may be configured to determine a feedforward term used to determine the duty cycle command based on a total source open command for a set of fluid input valves and at least one thermodynamic characteristic of the source fluid. In some embodiments, the thermodynamic characteristic may be the specific heat of the source fluid. In some embodiments, the target temperature of the vapor flow may be 111-112°C.

[0047] According to one embodiment of the present disclosure, a method for heating a fluid in a distillation device may include opening at least one fluid input valve to deliver a source fluid from a fluid source into a reservoir of the distillation device. The method may further include sensing the reservoir temperature of the source fluid in the reservoir via a temperature sensor. The method may further include sensing the vapor temperature of a vapor stream generated from the source fluid. The method may further include comparing the vapor temperature with a target vapor temperature using a processor. The method may further include inputting a delta between the vapor temperature and the target vapor temperature to a first controller to generate a first controller output. The method may further include providing input to a second controller, at least partially based on the first controller output and the reservoir temperature, to generate a second controller output. The method may further include modifying the second controller output to a modified second controller output based on the total open state time of at least one fluid input valve. The method may further include commanding a duty cycle for the heating element in the reservoir based on the modified second controller output and at least one limit.

[0048] In some embodiments, the target vapor temperature may be in the range of 108°C to 112°C. In some embodiments, at least one limit may include a maximum power consumption limit. In some embodiments, at least one limit may include a limit based at least partially on the power consumption of a compressor in the distillation device. In some embodiments, the method may further include determining the power consumption of the compressor and calculating the limit of at least one limit by subtracting the compressor's power consumption from a predefined power value. In some embodiments, the predefined power value may be defined as the maximum total power for the system. In some embodiments, at least one limit may include a predefined maximum duty cycle limit. In some embodiments, the predefined maximum duty cycle may be 90% duty cycle or less. In some embodiments, the target vapor temperature of the vapor flow may be state-specific. In some embodiments, the target temperature in the low-temperature distillate production state may be higher than the target temperature in the high-temperature distillate production state. In some embodiments, the target temperature in the first state may be 4°C higher than the target temperature in the second state. In some embodiments, the target temperature in the first state may be at least 95% of the target temperature in the second state, but less than the target temperature in the second state. In some embodiments, the second controller output to the modified second controller output may include determining a feedforward term based on a total source open command of at least one fluid input valve and at least one thermodynamic characteristic of the source fluid. In some embodiments, the thermodynamic characteristic may be the specific heat of the source fluid.

[0049] According to one embodiment of the present disclosure, a water distillation device may include a reservoir that selectively communicates with a fluid source via a set of source constant ratio valves. The device may further include an evaporator that communicates with the reservoir. The device may further include a steam chamber coupled to the evaporator and communicating with a compressor. The device may further include a concentrate reservoir having a concentrate level sensor attached to the steam chamber via an inlet path and configured to generate a concentrate level data signal indicating the fill percentage of the concentrate reservoir. The concentrate reservoir may be coupled to a concentrate flow path. The device may further include a condenser coupled to the outlet of the compressor and communicating with the condensate flow path. The device may further include first and second heat exchangers, including a heat exchange portion of the source fluid flow path from the fluid source. The heat exchange portion of the first heat exchanger may be in a heat exchange relationship with the condensate flow path, and the heat exchange portion of the second heat exchanger may be in a heat exchange relationship with the concentrate flow path. The heat exchange portion of the source fluid flow path may be located downstream of the source constant valve. The device may further include at least one distillate sensor communicating with a condensate flow path located downstream of the first heat exchanger. The device may further include a controller configured, at least in part, to determine the total open state time of the source constant valve based on concentrate data signals and a target concentrate ratio. The controller may be configured to allocate a percentage of the total open state command to each of the source constant valves based on at least one distillate sensor data signal from at least one distillate sensor.

[0050] In some embodiments, the condenser may include a condensing section and a condensate accumulation section. In some embodiments, the condenser may be in fluid communication with a condensate reservoir, including a condensate level sensor configured to monitor the level of condensate in the condensate reservoir and generate a condensate data signal indicating the fill percentage of the condensate storage area. The condensate reservoir may be located between the condenser and the concentrate flow path. In some embodiments, the controller may be configured to maintain the target fill percentage of the condensate storage area based on the output of a PID control loop that uses a target fill percentage and a delta between the target fill percentage and the current fill percentage, as indicated by the condensate data signal, as inputs. In some embodiments, the target fill percentage is at least equivalent to 1 liter and may be less than 2 liters. In some embodiments, the condenser may be in fluid communication with a condensate reservoir, including a condensate level sensor configured to monitor the level of condensate in the condensate reservoir and generate a condensate data signal indicating the fill percentage of the condensate reservoir. The condensate reservoir is located between the condenser and the concentrate flow path. In some embodiments, at least one distillate sensor may include a temperature sensor. In some embodiments, at least one distillate sensor data signal may be a temperature data signal indicating the current condensate temperature after passing through a heat exchanger. In some embodiments, the controller may be configured to distribute a percentage of total open state commands to each of the source constant valves based on a control loop that uses the target condensate temperature and the current condensate temperature as inputs. In some embodiments, the target temperature is at least 35°C but may be 40°C or less. In some embodiments, the target temperature is at least 20°C but may be 30°C or less. In some embodiments, the target temperature is at least 90°C but may be less than 100°C. In some embodiments, the distillation apparatus may further include a fluid source temperature sensor that generates a data signal indicating the temperature of the source fluid, and the target temperature may be determined by the controller in part based on the source temperature data signal. In some embodiments, the target temperature may be limited to a range of 20 to 25°C.

[0051] According to another embodiment of the present disclosure, the distillation system may include a distillation device that selectively fluidizes a fluid source via a set of source constant ratio valves. The distillation device may have a concentrate output coupled to a concentrate flow path, or a condensate output coupled to a condensate flow path. The system may further include first and second heat exchangers, each including a heat exchange portion of a source fluid flow path from a fluid source downstream of the source constant ratio valves. The heat exchange portion of the first heat exchanger may be in a heat exchange relationship with a condensate flow path, and the heat exchange portion of the second heat exchanger may be in a heat exchange relationship with a concentrate flow path. A dedicated source constant ratio valve may be present for each heat exchanger. The system may further include a condensate sensor assembly that communicates with a condensate flow path at a point downstream of the first heat exchanger. The system may further include a controller configured, in a first operating mode, to divert the commanded flow of a source fluid from a fluid source between source constant ratio valves based on a delta between a first target temperature and the current concentrate temperature received by the controller from a condensate sensor assembly. In the second operating mode, the controller may be configured to distribute the entire commanded flow to a source constant valve dedicated to the second heat exchanger, and to open the source constant valve dedicated to the first heat exchanger at a duty cycle which may be below a predefined limit.

[0052] In some embodiments, the predefined limit may be 5%. In some embodiments, the predefined limit may be 2%. In some embodiments, the predefined limit may be 0%. In some embodiments, the condensate sensor assembly may include redundant temperature sensors. In some embodiments, the first and second heat exchangers may be helical and formed by winding the heat exchangers around the outside of the distillation device. In some embodiments, the first operating mode may be a low-temperature distillate production state, and the second operating mode may be a high-temperature distillate production state. In some embodiments, the first target temperature is at least 35°C, but may be 40°C or less. In some embodiments, the first target temperature is at least 20°C, but may be less than 25°C. In some embodiments, the controller may be configured to open a source constant ratio valve dedicated to the first heat exchanger based on the second target temperature and the delta between the second target temperature and the current concentrate temperature in the second operating mode. In some embodiments, the second target temperature may be at least 65°C higher than the first target temperature. In some embodiments, the second target temperature may be at least 50°C higher than the first target temperature. In some embodiments, the second target temperature may be above 95°C and below 100°C. In some embodiments, the second target temperature may be 96°C. In some embodiments, the second target temperature may be at least twice the first target temperature. In some embodiments, the second target temperature may be at least 2.5 times the first target temperature. In some embodiments, the second target temperature may be at least 3.5 times the first target temperature. In some embodiments, the system may further include an evaporator level sensor located in the evaporator reservoir, which is in fluid communication with the evaporator of the distillation device. The controller may be configured, in a second operating state, to determine the total flow command based at least partially on an evaporator level data signal indicating the level of the water column in the evaporator reservoir. In some embodiments, the first target temperature is at least 20°C, but may be 30°C or less. In some embodiments, the first target temperature is 25°C.

[0053] According to another embodiment of the present disclosure, a method for controlling and distributing the flow of a source fluid into a distillation device may include sensing the concentrate level in a concentrate reservoir, which is in fluid communication with the evaporator of the distillation device, using a concentrate level sensor. The method may further include sensing the temperature of the product fluid produced by the distillation device at a point downstream of a product heat exchanger, which is positioned in a heat exchange relationship with the inflow source fluid. The method may further include determining the concentrate accumulation rate based on the concentrate level using a processor. The method may further include calculating a first delta between the concentrate accumulation rate and a first target concentrate accumulation rate and a second delta between the concentrate accumulation rate and a second target concentrate accumulation rate using a processor. The method may further include determining a first and second provisional open state command and a second provisional open state command with respect to first and second source inflow constant ratio valves using a processor. The first provisional open state command may be based on the first delta, and the second provisional open state command may be based on the second delta. The method may further include using a processor to calculate the final open state command from the provisional open state time command. The method may further include using a processor to split the final open state command between a first source inlet constant ratio valve and a second inlet constant ratio valve in the first operating state. The first source inlet constant ratio valve may be connected to a product heat exchanger. The split may be based on the delta between the target production temperature and the temperature of the product fluid. The method may further include using a processor to distribute the entire final open state command to a second source inlet constant ratio valve in the second operating state. The method may further include using a processor to open the first source inlet constant ratio valve in the second operating state via a command from the processor for a duty cycle below a predefined limit.

[0054] In some embodiments, the first target accumulation rate may exceed the second target accumulation rate. In some embodiments, calculating the final open state command may include inputting a first provisional open state command and a second provisional open state command to the slider. In some embodiments, calculating the final open state command may include generating a hybrid command from first and second provisional source open state commands. In some embodiments, calculating the final open state command may include determining a first state fraction and a second state fraction, multiplying the first provisional open state command by the first state fraction, and multiplying the second provisional open state command by the second state fraction. In some embodiments, calculating the final open state command includes adjusting the command mainly from the first provisional open state command to mainly the second provisional open state command during the transition between the first and second operating states. In some embodiments, calculating the final open state command may include adjusting the command entirely from the first provisional open state command to entirely the second provisional open state command during the transition between the first and second operating states. In some embodiments, the second operating state may be a high-temperature distillate production state. In some embodiments, the division may include determining an open state command for a first source inlet constant ratio valve based on the delta between the target product temperature and the product fluid temperature, and determining an open state command for a second source inlet constant ratio valve by subtracting the open state command from the final open state command from the first source inlet constant ratio valve. In some embodiments, the predefined limit may be less than 5%. In some embodiments, the predefined limit may be less than 2%. In some embodiments, the predefined limit may be 0%. In some embodiments, determining the second provisional open state command may further include sensing the level of the liquid column in the evaporator reservoir, which is in fluid communication with the evaporator, using an evaporator level sensor. The second provisional open state command may be based in part on the delta between the liquid column level and the target level of the liquid column. In some embodiments, the second provisional open state command may be based on the rate of change of the delta between the liquid column level and the target level of the liquid column.

[0055] According to one embodiment of the present disclosure, the medical system may comprise at least one concentrate fluid. The system may further comprise a distillation device having an evaporator, a condenser, and a purified product water heat exchanger having a source fluid flow path and a purified product water flow path in a heat exchange relationship with each other. The system may further comprise a medical treatment device, which may comprise a treatment fluid preparation circuit that selectively fluidizes the purified product water flow path via a point-of-use valve. The medical treatment device may comprise a treatment device processor configured to command a mixture of at least one concentrate and purified water and generate a prescribed treatment fluid using the treatment fluid preparation circuit. The system may further comprise a communication link between the treatment device processor of the medical treatment device and the distillation device processor of the distillation device. The medical treatment device processor may be configured to transmit mode commands to the distillation device processor. The system may further comprise a sensor assembly communicating with the purified product water flow path. The system may further comprise a source valve intermediate between the fluid source and the source fluid flow path. The distillation device processor may be configured, at least in part, to actuate the source valve based on mode commands and data from the sensor assembly.

[0056] In some embodiments, the sensor assembly may include at least one temperature sensor and at least one conductive sensor. In some embodiments, the distillation device processor may be configured at least partially to actuate the source valve based on a mode command and temperature data from the sensor assembly. In some embodiments, the distillation device processor may be configured at least partially to actuate the source valve based on a mode command, data from the sensor assembly, and a target setpoint for purified water. In some embodiments, the target setpoint may be a temperature setpoint. In some embodiments, the target setpoint may be determined by the distillation device processor based on a mode command. In some embodiments, the target setpoint may be based on a first mode command, which may be in the range of 20 to 35°, and the target setpoint may be based on a second mode command, which may be above 90°C.

[0057] In some embodiments, the medical treatment device may be a dialysis machine. In some embodiments, the medical treatment device may be a hemodialysis device. In some embodiments, the treatment fluid may be a dialysis fluid. In some embodiments, the condenser may include a condensation section and a product storage section. The product storage section may have a volume of at least 1 liter. In some embodiments, the distillation device processor may further be configured, at least in part, to control the operation of the compressor motor of the distillation device based on a mode command. In some embodiments, the distillation device processor may further be configured, at least in part, to control the operation of the concentrate outlet valve of the distillation device based on a mode command.

[0058] According to one embodiment of the present disclosure, a medical system may include a distillation device having an evaporator, a source input flow path to a source inlet that is in fluid communication with the evaporator, a condenser, and a purified product water output flow path that is in fluid communication with the condenser. The system may further include first and second filters in the source inlet flow path. The system may further include a plurality of pressure sensors, including a first pressure sensor upstream of the first filter and a second pressure sensor downstream of the second filter. The system may further include a medical treatment device, which includes a treatment fluid preparation circuit that selectively communicates with the purified product water output flow path via a point-of-use valve. The system may further include a communication link between a medical treatment device processor and a distillation device processor of the distillation device. The distillation device processor may be configured to perform a first filter replacement check based on data from the plurality of pressure sensors, and the medical device processor may perform a second filter replacement check, and if either the first or second filter replacement check fails, it may be configured to command the distillation device processor via the communication link to enter filter replacement mode.

[0059] In some embodiments, the second filter replacement check may include checking the number of days elapsed since the installation of the first and second filters against a limit. In some embodiments, the medical treatment device may include a graphical user interface. In some embodiments, the second filter replacement check may include checking user input on the graphical user interface against at least one predefined criterion. In some embodiments, the system may further include a sampling port located between the first and second filters, where the predefined criterion may be a water chemical properties test specimen criterion. In some embodiments, the water chemical properties test specimen criterion may be a chlorine treatment level criterion. In some embodiments, the distillation device processor may be configured to command cleaning of the first and second filters prior to at least one of the first or second filter replacement checks. In some embodiments, the distillation device processor may be configured to perform the first filter replacement check based on a filter output pressure data signal from a second pressure sensor. In some embodiments, the distillation device processor may be configured to indicate a failure of the first filter replacement check when the filter output pressure falls below a threshold. In some embodiments, the distillation device processor may be configured to perform a first filter replacement check based on a delta between the pressures upstream of the first and second filters, as indicated by a first pressure sensor, and the pressures downstream of the first and second filters, as indicated by a second pressure sensor. In some embodiments, the distillation device processor may be configured to indicate a failure of the first filter replacement check when the delta is below a threshold.

[0060] According to another embodiment of the present disclosure, the medical system may include a distillation device having a source water input and a fluid output flow path. The system may further include a medical treatment device including a plurality of fluid flow paths, a plurality of valves, at least one fluid pump, and a fluid inlet that selectively communicates with the fluid output flow path via a point-of-use valve. The system may further include a communication link between the medical treatment device and the distillation device. The system may further include a sensor assembly communicating with the fluid output flow path. The system may further include a treatment device processor configured to actuate a plurality of valves and at least one fluid pump to pump high-temperature fluid through a plurality of fluid flow paths. The system may further include a distillation device processor configured to control the operation of a distillation device based on at least one data signal from a sensor assembly and a mode command transmitted from a medical device processor of a medical treatment device via a communication link, and to produce and output high-temperature fluid to a fluid output flow path between a first cycle in which the distillation device processor commands the point-of-use valve to be opened and a second cycle in which the distillation device processor commands the point-of-use valve to be closed and the valve to a flow path communicating with the fluid output flow path to be opened.

[0061] In some embodiments, the source water input may be in fluid communication with a temperature-uncontrolled fluid source. In some embodiments, the medical treatment device may be a dialysis machine. In some embodiments, the medical treatment device may be a hemodialysis machine. In some embodiments, the fluid flow paths may include a first flow path and a second flow path, separated from each other by a semipermeable membrane. In some embodiments, the fluid flow paths may be contained within at least a blood pumping cassette and a dialysate pumping cassette. In some embodiments, the medical treatment device may include a fluid reservoir, and the treatment device processor may be configured to send a signal to the distillation device processor to terminate the first cycle based on the amount of high-temperature fluid contained in the fluid reservoir. In some embodiments, the medical treatment device may include a heater. In some embodiments, at least one data signal may include at least one temperature data signal. In some embodiments, the distillation device may include a compressor, and the distillation device processor may be configured to control the operation of the compressor via a compressor speed command determined partly based on a mode command. In some embodiments, the distillation device processor may be configured to control the operation of the distillation device based on at least one data signal and another mode command transmitted from the therapeutic device processor via a communication link, to produce a medical therapeutic fluid component and output it to a fluid output flow path. In some embodiments, the multiple flow paths may comprise a medical therapeutic fluid mixing circuit, and the therapeutic device processor may be configured to command the operation of at least one pump and multiple valves to mix the medical therapeutic fluid component with at least one concentrate that fluid-communicates with the multiple flow paths according to a predetermined prescription.

[0062] According to another embodiment of the present disclosure, the water distillation apparatus may include a reservoir having a source fluid input. The apparatus may further include an evaporator, which is in fluid communication with the source fluid input via the reservoir. The apparatus may further include a condenser, which includes a condensing section and a condensate storage section. The apparatus may further include an auxiliary condensate reservoir, which is in fluid communication with the condensate storage section and is attached to the condenser adjacent to the storage surface of the storage section. The auxiliary condensate reservoir may be fluidly coupled to a point-of-use device via a condensate flow path. The apparatus may further include a condensate level sensor configured to monitor the level of condensate in the storage section and generate a data signal indicating the filling level of the storage section. The apparatus may further include a controller configured, at least in part, to control the operation of a bypass valve included in the condensate flow path based on the data signal and a target condensate level. The controller may further be configured to command the bypass valve to a closed state based on the derivative of the data signal.

[0063] In some embodiments, the storage section may have a volume of less than 10 liters. In some embodiments, the condensate level sensor may include a float assembly mounted on a pivot. The float assembly may be displaceable about the pivot over a displacement range that includes a point at the same height as the range of filling levels in the storage section. In some embodiments, the condensate level sensor may include a float displaceable along a displacement axis over a displacement range that includes a point at the same height as the range of filling levels in the storage section. In some embodiments, the condensate level sensor may include a float displaceable along a displacement path through a displacement range that includes a point at the same height as the range of filling levels in the storage section. In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of a data signal that exceeds a predefined minimum threshold. In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of a data signal that has a negative value exceeding a predefined magnitude. In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of a data signal that indicates a point-of-use device is consuming condensate from the distillation apparatus. In some embodiments, the device may further include a heat exchanger that includes a portion of the condensate flow path and a portion of the source flow path coupled to a water source and a source fluid input. In some embodiments, the device may further include a sensing assembly that communicates with a condensate flow path downstream of the portion of the condensate flow path contained within the heat exchanger. The sensing assembly may be configured to output a temperature data signal. In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of the temperature data signal. In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of the temperature data signal that exceeds a predefined maximum threshold. In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of the temperature data signal that has a positive value exceeding a predefined magnitude.In some embodiments, the controller may be configured to command a bypass valve to close based on the derivative of a temperature data signal indicating that the point-of-use device is consuming condensate from the distillation apparatus. In some embodiments, the controller may be configured to command a bypass valve to close based on the integral of the derivative of a temperature data signal. In some embodiments, the controller may be configured to command a bypass valve to close based on the integral of the derivative of a temperature data signal that exceeds a predefined maximum threshold. In some embodiments, the controller may be configured to command a bypass valve to close based on the integral of the derivative of a temperature data signal that has a positive value exceeding a predefined magnitude. In some embodiments, the controller may be configured to command a bypass valve to close based on the integral of the derivative of a temperature data signal indicating that a point-of-use device is consuming condensate from a distillation apparatus.

[0064] According to another embodiment of the present disclosure, the water distillation apparatus may include a reservoir having a source fluid input. The apparatus may further include an evaporator, which is in fluid communication with the source fluid input via the reservoir. The apparatus may further include a condenser, which is fluidly coupled to a point-of-use device via a condensate flow path. The apparatus may further include a condensate level sensor configured to generate a data signal indicating the condenser's filling level. The apparatus may further include a heat exchanger, which includes a portion of the condensate flow path and a portion of the source flow path coupled to a water source and a source fluid input. The apparatus may further include a sensing assembly communicating with a condensate flow path downstream of the portion of the condensate flow path contained within the heat exchanger. The sensing assembly may be configured to output a sensor assembly data signal. The apparatus may further include a controller configured, at least in part, to control the operation of a bypass valve contained within the condensate flow path based on a data signal and a target condensate level. The controller may further be configured to command the bypass valve to a closed state based on the derivative of the sensor assembly data signal.

[0065] In some embodiments, the controller may be configured to command a bypass valve to a closed state based on the derivative of the sensor assembly data signal. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on the derivative of the sensor assembly data signal that exceeds a predefined maximum threshold. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on the derivative of the sensor assembly data signal that has a positive value exceeding a predefined magnitude. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on the derivative of the sensor assembly data signal indicating that a point-of-use device is consuming condensate from the distillation apparatus. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on an integral calculated using the sensor assembly data signal. In some embodiments, the integral may be calculated from the derivative of the sensor assembly data signal. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on an integral that exceeds a predefined maximum threshold. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on an integral that has a positive value exceeding a predefined magnitude. In some embodiments, the controller may be configured to command a bypass valve to a closed state based on an integral indicating that a point-of-use device is consuming condensate from the distillation apparatus. In some embodiments, the sensor assembly data signal may be a temperature data signal.

[0066] According to another embodiment of the present disclosure, a water purification system for outputting a process flow at a controlled temperature may include a distillation device that selectively fluidizes a fluid source via a set of source constant ratio valves. The distillation device may each have a concentrate output and a distillate output, coupled to a concentrate flow path and a distillate flow path, respectively. The system may further include a first heat exchanger including a portion of the distillate flow path and a second heat exchanger including a portion of the concentrate flow path. The flow path from the fluid source may be in a heat exchange relationship with each of the first and second heat exchangers. The system may further include a distillate sensor assembly configured to communicate with a distillate flow path downstream of the portion of the distillate flow path contained within the first heat exchanger and to generate a distillate temperature measurement. The system may further include a controller configured to activate a set of input source valves based on a first multimodal control loop that generates a certain number of provisional total open state commands for source valves, a slider that generates a single total open state command from the number of provisional commands, and a second control loop that receives a distillate temperature measurement, a first target temperature, and a second target temperature, thereby distributing a single total open state command among all of the input source valves and adjusting the condensate temperature to a temperature setpoint.

[0067] In some embodiments, the system may further include an electronics box that is in thermal communication with the source fluid flow path. In some embodiments, the second control loop may at least partially distribute total open state commands by generating provisional distribution commands based at least partially on a first target temperature and a second target temperature and inputting the provisional distribution commands to a second slider. In some embodiments, the controller may be configured to operate in multiple operating states, and the temperature setpoint is state-dependent. In some embodiments, the controller may be configured to transition between a first state of multiple operating states and a second state of multiple operating states. In some embodiments, at least one of the first multimodal control loop and the second control loop may include one or more PID control loops. In some embodiments, one or more PID control loops may include a feedforward term that modifies the output of one or more PID loops. In some embodiments, the number of provisional total open state commands may be regulated by the output of at least one regulator control loop. In some embodiments, one of the at least one regulator control loop may be configured at least partially to produce an output based on the concentrate temperature. In some embodiments, the number of at least one of the provisional total open state commands may be adjusted by a feedforward term. In some embodiments, at least one of the provisional total open state commands may be modified, at least in part, based on a pre-allocated source duty cycle command determined based on the concentrate temperature sensed by a concentrate sensor assembly communicating with a portion of the concentrate flow path downstream of the portion of the concentrate flow path contained within the second heat exchanger. In some embodiments, the second control loop may be configured to generate its output, at least in part, based on the target electronic device temperature and the current electronic device temperature measured by an electronic device temperature sensor. In some embodiments, the temperature setpoint may be adjusted by the controller, at least in part, based on a source fluid temperature data signal generated by a source fluid temperature sensor.

[0068] According to another embodiment of the present disclosure, a water purification system for outputting a process flow at a controlled temperature may include a distillation device that selectively fluidizes a fluid source via a set of source constant ratio valves. The distillation device may each have a concentrate output and a distillate output, which are coupled to a concentrate flow path and a distillate flow path. The concentrate output may be located within a concentrate reservoir of the distillation device. The system may further include a first heat exchanger and a second heat exchanger, which include a portion of the distillate flow path, and the flow path from the fluid source is in a heat exchange relationship with the first and second heat exchangers, respectively. The system may further include a distillate sensor assembly configured to communicate with a distillate flow path downstream of the portion of the distillate flow path contained within the first heat exchanger and to generate a distillate temperature measurement. The system may further include a concentrate level sensor located within a concentrate reservoir and configured to output a concentrate data signal. The system may further include a controller configured at least in part to determine the total open state time of the source control valves based on the concentrate data signal, the target concentrate ratio, and the minimum open state time for at least one of the source control valves. The controller may also be configured in part to allocate a percentage of the total open state command to each of the source control valves based on the distillate temperature measurement and the minimum open state time.

[0069] In some embodiments, the system may further include at least one source sensor communicating with a source fluid flow path. In some embodiments, the controller may be configured to distribute a percentage of the total open state command to each of the source constant valves, in part, based on the source sensor data signal. In some embodiments, the source sensor data signal may be a temperature data signal indicating the current source fluid temperature. In some embodiments, the controller may be configured to distribute a percentage of the total open state command to each of the source constant valves, based on a control loop that uses a target distillate temperature determined by the controller based on the current source fluid temperature. In some embodiments, the system may further include at least one concentrate temperature sensor communicating with a concentrate fluid flow path. In some embodiments, the controller may be configured to determine the total open state time of the source constant valves, at least in part, based on a concentrate temperature data signal generated by at least one concentrate temperature sensor. In some embodiments, the controller may be configured to distribute a percentage of the total open state command to each of the source constant valves, based on a control loop that uses the target concentrate temperature and the concentrate temperature data signal as inputs. In some embodiments, the controller may allocate a non-zero percentage of the total open state commands to at least one of the set of source-fixed valves. In some embodiments, the controller may be configured to determine the total open state time of the source-fixed valves, at least in part, based on a feedforward term.

[0070] According to another embodiment of the present disclosure, a method for calibrating the operating speed setpoint of an impeller compressor located in a fluid communication path between an evaporator and a condenser of a vapor compression distillation device, wherein the impeller compressor is for compressing a low-pressure flow generated in the evaporator into a high-pressure steam output to the condenser, and may include driving the impeller rotation to a first speed based on a target low-pressure steam temperature and a low-pressure steam temperature measured from a low-pressure steam temperature sensor. The method may further include performing a binary type lookup to determine the operating speed setpoint.

[0071] In some embodiments, performing a binary type lookup may include calculating a velocity command based on the target low-pressure steam temperature and the measured low-pressure steam temperature. In some embodiments, performing a binary type lookup may include calculating a delta between the velocity command and the starting velocity and comparing the delta with a certain range. In some embodiments, performing a binary type lookup may include narrowing the range and resetting the starting speed when the delta is out of range. In some embodiments, performing a binary type lookup may include entering a stabilization state for a certain time period before resetting the starting speed. In some embodiments, performing a binary type lookup may include comparing the measured low-pressure steam temperature with the target low-pressure steam temperature. In some embodiments, performing a binary type lookup may include incrementing a timer when the measured low-pressure steam temperature relative to the target low-pressure steam temperature is within a mutually predefined range. In some embodiments, performing a binary type lookup may include saving the current speed command as an operating speed setpoint when the timer has been incremented to a predetermined value.

[0072] According to one embodiment of the present disclosure, a fluid distillation apparatus may comprise at least one controller and a source inlet that selectively communicates with a fluid source via at least one valve. The fluid vapor distillation apparatus may further comprise an evaporator that communicates with the source inlet. The fluid vapor distillation apparatus may further comprise a vapor chamber coupled to the evaporator and communicating with a compressor. The fluid vapor distillation apparatus may further include a concentrate reservoir, which is attached to the steam chamber via an inlet path. The concentrate reservoir may be positioned laterally to the steam chamber such that at least a portion of the concentrate reservoir is at the same height as the steam chamber. The fluid vapor distillation apparatus may further include a condenser, which is in fluid communication with the outlet of a compressor via a linear flow path. The linear flow path may include a condenser inlet having a windowed compartment with a plurality of openings. The openings may establish the flow path from the condenser inlet to the condenser. The fluid vapor distillation apparatus may further include a product process flow reservoir, which is coupled to the condenser by a product reservoir inlet. The product process flow reservoir may be positioned laterally to the condenser such that at least a portion of the product process flow reservoir is at the same height as the condenser.

[0073] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a plate. The plate may have a compartment that extends into the concentrate reservoir at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate reservoir and divide the concentrate reservoir into a first part and a second shielding part. In some embodiments, the fluid vapor distillation apparatus may further include a vent path extending from the concentrate reservoir into the steam chamber. In some embodiments, the vent path may extend substantially parallel to the inflow path with respect to gravity and be located above it. In some embodiments, the product reservoir inlet may be adjacent to the product accumulation surface of the condenser. In some embodiments, the compressor may be driven by a motor mounted in a receiving well fitted into the side of the steam chamber. In some embodiments, the compressor may include an impeller that passes through at least a portion of the steam chamber and rotates about an axis that is offset from but parallel to the center of the longitudinal axis of the steam chamber.

[0074] According to another embodiment of the present disclosure, the steam distillation apparatus may comprise a reservoir and an evaporator having a first side in communication with the reservoir. The evaporator may have a second side in fluid communication with a steam chamber. The steam distillation apparatus may further comprise a concentrate reservoir having a first portion and a second portion, which is attached to the steam chamber via an inflow path. The second portion may consist at least partially of an obstruction. The obstruction may extend laterally to the first portion within the concentrate reservoir, and the concentrate reservoir may be divided into an unshielded section and a shielded section. The steam distillation apparatus may further comprise a float assembly located within the shielded section. The float assembly may be displaceable over a displacement range including a point at the same height as all steam chamber liquid levels within an expected range of steam chamber liquid levels. The steam distillation apparatus may further comprise a sensor configured to monitor the position of the float assembly and to output a data signal indicating the liquid level in the steam chamber based on the position of the float assembly. The steam distillation apparatus may further include a compressor having an inlet for establishing fluid communication with a steam chamber and an outlet for establishing fluid communication with a condenser.

[0075] In some embodiments, the sensor may be an encoder. In some embodiments, the float assembly may include at least one magnet. In some embodiments, the sensor may be a Hall effect sensor. In some embodiments, the float assembly may be mounted on a pivot. In some embodiments, the float assembly may be displaceable about the pivot. In some embodiments, the obstruction may extend into the concentrate reservoir at an angle substantially perpendicular to the first portion of the inflow path. In some embodiments, the steam distillation apparatus may further include a vent path extending from the concentrate reservoir into the steam chamber. In some embodiments, the vent path may extend parallel to and above the first portion of the inflow path. In some embodiments, the vent path may have a smaller cross-sectional area than that of the first portion of the inflow path.

[0076] According to another embodiment of the present disclosure, the steam distillation apparatus may include a reservoir having a source fluid input. The steam distillation apparatus may further include an evaporator having a first side that is in fluid communication with the source fluid input via the reservoir, and a second side that is in fluid communication with a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into low-pressure steam and concentrate as the source fluid progresses toward the steam chamber. The steam distillation apparatus may further include a concentrate reservoir mounted to and laterally to the steam chamber. The concentrate reservoir may include a concentrate level sensor configured to monitor the level of concentrate in the steam chamber and generate a data signal indicating the level of concentrate. The steam distillation apparatus may further include a compressor having a low-pressure steam inlet that establishes fluid communication with the steam chamber and a high-pressure steam outlet that establishes fluid communication with a condenser via a condenser inlet. The steam distillation apparatus may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with multiple external surfaces of the evaporator. The condenser may include a condensing section and a condensate storage or reservoir section. The steam distillation apparatus may further include an auxiliary condensate reservoir in fluid communication with the condensate storage section. The auxiliary condensate reservoir may be mounted on the condenser adjacent to the storage surface of the storage section and may include a condensate level sensor configured to monitor the level of condensate in the storage section and generate a data signal indicating the percentage that the storage section is filled with condensate.

[0077] In some embodiments, the storage portion may have a volume of less than 10 liters. In some embodiments, the multiple external surfaces may be the external surfaces of multiple evaporator tubes contained within the evaporator. In some embodiments, the multiple external surfaces may be the external surfaces of 90 to 100 evaporator tubes contained within the evaporator. In some embodiments, the multiple external surfaces may be the external surfaces of 70 to 80 evaporator tubes contained within the evaporator. In some embodiments, the condensate level sensor may include a float assembly that is pivotally mounted. In some embodiments, the float assembly may be displaceable about the pivot over a displacement range that includes points at the same height as the range of levels defined by the accumulation portion. In some embodiments, the concentrate level sensor may include a float assembly that is located within a shielded section of the concentrate reservoir, separated from the unshielded portion of the concentrate reservoir by a barrier. In some embodiments, the float assembly may be pivotally mounted and displaceable about the pivot over a displacement range that includes points at the same height as all steam chamber concentrate levels within the expected range of steam chamber liquid levels. In some embodiments, the concentrate level sensor may be located within a sleeve that forms a barrier.

[0078] According to another embodiment of the present disclosure, a concentrate level control system for a fluid vapor distillation apparatus may include a source fluid input that selectively fluidizes a source fluid reservoir via at least one input valve. The concentrate level control system may further include an evaporator that fluidizes the source input and fluidizes a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into a steam flow and a concentrate flow as the source fluid progresses toward the steam chamber. The concentrate level control system may further include a concentrate reservoir that is attached to the steam chamber via an inlet path and positioned laterally thereto, and selectively communicates with a concentrate destination via an outlet valve. The concentrate level control system may further include a concentrate level sensor configured to generate a data signal indicating the concentrate level in the steam chamber. The concentrate level control system may further include a controller configured to carefully modify the concentrate level in a predetermined pattern by controlling the operation of at least one inlet valve via a fluid input control loop and by analyzing the data signal. The controller may also be configured to activate the outlet valve to a closed state when the data signal indicating the concentrate level falls below a first threshold, and to activate the outlet valve to an open state when the concentrate level exceeds a second threshold.

[0079] In some embodiments, a predetermined pattern may generate a sawtooth waveform when the concentrate level is plotted over time. In some embodiments, the period of the sawtooth waveform may depend, at least in part, on a fluid input command from a fluid input control loop. In some embodiments, the fluid input command may be determined based on a pre-determined target concentrate production rate. In some embodiments, the controller may be configured to operate in multiple operating states, and the pre-defined target concentrate production rate may be state-specific. In some embodiments, the controller may analyze the data signal on a pre-defined basis. In some embodiments, the concentrate level may be assigned a pre-defined expected range, and a first threshold may be less than or equal to 50% of the maximum level of the expected range. In some embodiments, the first threshold may be 40% to 50% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a pre-defined expected range, and a second threshold may be greater than or equal to 50% of the maximum level of the expected range. In some embodiments, the second threshold may be 50% to 60% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and the first threshold may be less than or equal to 40% of the maximum level of the expected range. In some embodiments, the first threshold may be 40% to 30% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and the second threshold may be greater than or equal to 45% of the maximum level of the expected range. In some embodiments, the second threshold may be 45% to 55% of the maximum level of the expected range. In some embodiments, the concentrate level may be assigned a predefined expected range, and the first and second thresholds may be defined as percentages of the maximum level of the expected range. The second threshold may be 4 to 20 percent above the first threshold. In some embodiments, the concentrate destination is a mixing tank.

[0080] According to another embodiment of the present disclosure, a method for controlling the level of concentrate in a distillation device and matching the fluid flow within the distillation device may include introducing a source fluid into the distillation device through at least one inlet valve. The method may further include evaporating at least a portion of the source fluid as it proceeds toward the steam chamber to generate steam and concentrate. The method may further include collecting the concentrate in a concentrate reservoir, which is attached to and positioned laterally to the steam chamber, via an inlet path. The method may further include providing a data signal indicating the concentrate level in the steam chamber from a concentrate level sensor located in the concentrate reservoir. The method may further include modifying the concentrate level in a predetermined pattern by using a controller to control the operation of at least one inlet valve via a fluid input control loop, analyzing the data signal, and operating the outlet valve of the concentrate reservoir to a closed state when the data signal indicating the concentrate level falls below a first threshold, and to an open state when the concentrate level exceeds a second threshold.

[0081] In some embodiments, modifying the concentrate level may include modifying the concentrate level to generate a sawtooth waveform when the concentrate level is plotted over time. In some embodiments, analyzing the data signal may include analyzing the data signal on a predetermined basis. In some embodiments, the method may further include assigning a predefined expected range to the concentrate level and setting a first threshold so that it is less than or equal to 50% of the maximum level of the expected range. In some embodiments, setting the first threshold may include setting the threshold to 40% to 50% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range to the concentrate level and setting a second threshold so that it is greater than or equal to 50% of the maximum level of the expected range. In some embodiments, setting the second threshold may include setting the second threshold to 50% to 60% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range to the concentrate level and setting a first threshold so that it is less than or equal to 40% of the maximum level of the expected range. In some embodiments, setting the first threshold may include setting the threshold to 40% to 30% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range of concentrate levels and setting a second threshold to be above or equal to 45% of the maximum level of the expected range. In some embodiments, setting the second threshold may include setting the second threshold to 45% to 55% of the maximum level of the expected range. In some embodiments, the method may further include assigning a predefined expected range of concentrate levels and setting the first and second thresholds as percentages of the maximum level of the expected range, where the second threshold is a 4 to 20 percent point above the first threshold.

[0082] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation device to a desired temperature may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator that fluidizes the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The system may further include a condenser that fluidizes the compressor and is configured to convert the pressurized vapor from the compressor into a condensate. The system may further include a condensate flow path and a concentrated flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir. The heat exchange portion may be downstream of the source fluid input valves. The system may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. A condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The system may further include a controller configured to operate a set of input source valves based on a first control loop that controls the total open time for all input source valves in a set of input source valves, and a second control loop that receives data signals and a requested temperature, divides the total open time for all input source valves, and adjusts the condensate temperature to the requested temperature.

[0083] In some embodiments, the heat exchange portions of the source fluid flow paths in the first and second heat exchangers may be arranged countercurrently to their respective condensate and concentrate flow paths. In some embodiments, the system may further include a destination device that fluidically communicates with the condensate flow path via a point-of-use valve. In some embodiments, the required temperature may be generated by the destination device. In some embodiments, the destination device may be a medical system. In some embodiments, the medical system may be configured to mix at least one dialysate solution. In some embodiments, the destination device may be a dialysis machine. In some embodiments, the destination device may be a hemodialysis machine. In some embodiments, at least one of the first and second control loops may be a PID control loop. In some embodiments, the gain of at least one of the terms in the PID control loop may be zero. In some embodiments, a feedforward term may be combined with the output of the second control loop. In some embodiments, the feedforward term may be based on an estimated division of the total open time. In some embodiments, the system may further include a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level in the distillation device. A first control loop may be configured to receive the target concentrate level and the current concentrate level data signal as inputs to the first control loop. In some embodiments, the controller may further be configured to adjust the heater duty cycle at least in part based on the total open time for all input source valves of a set of input source valves. In some embodiments, the controller may be configured to increase the heater duty cycle when the open time for all input source valves of a set of input source valves is increased.

[0084] According to another embodiment of the present disclosure, a method for controlling the temperature of the product process flow of a distillation device to a required temperature may include controlling the flow of the source fluid input to the distillation device by using a controller to actuate a set of source fluid valves. The method may further include converting at least a portion of the source fluid input into vapor and concentrate in an evaporator. The method may further include condensing the vapor into condensate in a condenser. The method may further include removing at least a portion of the condensate and concentrate from the distillation device through separate condensate and concentrate flow paths. The method may further include exchanging heat between the source fluid flow and the condensate flow path in a first heat exchanger and exchanging heat between the source fluid flow and the concentrate flow path in a second heat exchanger. The method may further include providing a condensate temperature data signal to the controller from a temperature sensor on the condensate flow path located downstream of the first heat exchanger. The method may further include using a controller to determine the total open state time for each set of fluid input valves based on a first control loop, and to divide the total open state time between sets of fluid input valves based on a second control loop that receives a temperature data signal and a required temperature.

[0085] In some embodiments, the method may further include flowing the condensate and concentrate through a condensate and concentrate flow path in the counter-flow direction with respect to the flow of the source fluid. In some embodiments, the method may further include providing the condensate to a destination device by activating a point-of-use valve downstream of a temperature sensor. In some embodiments, the required temperature may be generated by the destination device. In some embodiments, the destination device may be a medical system. In some embodiments, the method may further include mixing dialysate using the condensate. In some embodiments, the destination device may be a dialysis machine. In some embodiments, the destination device may be a hemodialysis machine. In some embodiments, at least one of the first and second control loops may be a PID control loop. In some embodiments, the method may further include setting at least one of the gains of the PID control loop to zero. In some embodiments, the method may further include combining a feedforward term with the output of the second control loop. In some embodiments, the method may further include determining the feedforward term based on an estimated division of the total open state time. In some embodiments, the method further includes inputting the current concentrate level and target concentrate level, provided by a concentrate level sensor, into a first control loop. In some embodiments, the method may further include, at least in part, adjusting the heater duty cycle based on the total open state time for all input source valves of a set of input source valves. In some embodiments, adjusting the heater duty cycle may include increasing the heater duty cycle when the open state time for all input source valves of a set of input source valves is increased.

[0086] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation device to a required temperature may include a first source fluid input and a second fluid source input, each selectively fluid-communicating with a source fluid reservoir via a first set of fluid input valves and a second set of fluid input valves, respectively. The system may further include an evaporator, which is fluid-communicating with the first and second source fluid inputs and with a compressor. The evaporator may have heating elements for converting the source fluid from the first and second source fluid inputs into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The system may further include a condenser, which is fluid-communicating with the compressor. The condenser may be configured to convert pressurized vapor from the compressor into a condensate. The system may further include a condensate flow path and a concentrated flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from a source fluid reservoir, the heat exchange portion being downstream of a set of source fluid input valves. The system may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. The condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The system may further include a controller configured to actuate the first set of input source valves based on a first control loop that controls the total open time for all input source valves of the first set of input source valves, and a second control loop that receives a data signal and a requested temperature, divides the total open time for all input source valves of the first set of input source valves, and adjusts the condensate temperature to the requested temperature. The controller may monitor at least one process variable and be configured to actuate a second set of input source valves when at least one of the process variables is outside a predefined threshold.

[0087] In some embodiments, the first set of fluid input valves may include at least one valve not included in the second set of fluid input valves. In some embodiments, one of the first and second source fluid inputs may be temperature controlled. In some embodiments, the second source fluid input may be temperature controlled. In some embodiments, the second source fluid input may be a high-temperature fluid input. In some embodiments, at least one process variable monitored by the controller may be a heating element duty cycle. In some embodiments, at least one process variable monitored by the controller may be an output of a first control loop. In some embodiments, at least one process variable may be the compressor speed. In some embodiments, the heat exchange portion of the source fluid flow path may be a common flow path for fluids from the first and second source fluid inputs.

[0088] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation device to a required temperature may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator that selectively fluidizes the source fluid input and fluidizes a compressor via a bypass valve. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The system may further include a condenser, which is in fluid communication with the compressor, configured to convert the pressurized vapor from the compressor into condensate. The system may further include a condensate flow path and a concentrated flow path, which include separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, the heat exchange portion being downstream of the source fluid input valve. The system may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. The condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The system may further include a controller configured to actuate the set of input source valves based on a first control loop that controls the total open time for all input source valves in the set of input source valves, and a second control loop that receives data signals and a requested temperature, divides the total open time for all input source valves by this loop, and adjusts the condensate temperature to the requested temperature. Bypass valves may be located in the source fluid flow path upstream of the heat exchange portion of the source fluid flow path. Bypass valves may have a bypass valve state that directs the fluid from the source reservoir to the drain destination. The controller may be configured to actuate the bypass valve state when the controller determines that at least one process variable is outside a predetermined threshold.

[0089] In some embodiments, at least one process variable may be the relationship between the condensate temperature and the source fluid temperature provided by the source fluid temperature sensor. In some embodiments, at least one process variable may be the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, at least one process variable may be defined at least partially by the condensate temperature and the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, the controller may modify the duty cycle of at least one of the input source valves when the bypass valve is in the bypass valve state. In some embodiments, the controller may increase the duty cycle of at least one of the input source valves when the bypass valve is in the bypass valve state. In some embodiments, the controller may modify the duty cycle of at least one of the input source valves to 90-100% when the bypass valve is in the bypass valve state. In some embodiments, one of the at least one of the input source valves may be a valve that controls the flow of source fluid through the heat exchange portion of the first heat exchanger.

[0090] According to another embodiment of the present disclosure, a temperature control system for controlling the temperature of the product process flow of a distillation system to a required temperature may include a source fluid input that selectively communicates with a source fluid reservoir via a set of fluid input valves. The system may further include a distillation device configured to generate concentrated and condensed flow. The system may further include a condensate flow path and a concentrate flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, the heat exchange portion being downstream of the source fluid input valve. The system may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. The condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The system may further include a point-of-use device that selectively communicates with the condensate flow path. The point-of-use device may have an outlet flow path for the output fluid generated by the point-of-use device. The output flow path may have a third heat exchanger, which includes a heat exchange portion of a branch in the source fluid flow path. The system may further include a controller configured to actuate a set of input source valves based on a first control loop and a second control loop, and based on at least one process variable, which control the fluid flow of the source fluid through the heat exchange portions of the first and second heat exchangers. The controller may actuate a branch valve to a branch in the source fluid flow path when at least one process variable is outside a predetermined threshold.

[0091] In some embodiments, at least one process variable may be the relationship between the condensate temperature and the source fluid temperature provided by a source fluid temperature sensor. In some embodiments, at least one process variable may be the source fluid temperature sensed by a source fluid temperature sensor. In some embodiments, at least one process variable may be defined at least partially by the condensate temperature and the source fluid temperature sensed by a source fluid temperature sensor. In some embodiments, the point-of-use device may be a medical device. In some embodiments, the point-of-use device is a dialysis machine. In some embodiments, the point-of-use device is a hemodialysis machine or a peritoneal dialysis machine. In some embodiments, the point-of-use device may be a dialysate mixing device. In some embodiments, the branching of the source fluid flow path may be located upstream of the heat exchange portion of the source fluid flow path in the first and second heat exchangers. In some embodiments, the output fluid may be dialysate wastewater.

[0092] According to another embodiment of the present disclosure, a condensate accumulation rate control system for controlling the rate of condensate accumulation in a distillation device may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator that fluidizes the source input and fluidizes a compressor having an impeller operably coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The system may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator. The system may further include a condensate level sensor configured to sense the current level of condensate in the condenser. The system may further include at least one controller configured to control the rotational speed of the impeller by periodically generating impeller motor commands based on the last motor speed command, a motor speed target, and a speed command increment limit. The motor speed target may be calculated by a control loop that receives the current condensate level and a desired condensate level as control loop inputs.

[0093] In some embodiments, the speed command increment limit may be ≤10 rpm / second. In some embodiments, the speed command increment limit may be ≤5 rpm / second. In some embodiments, the controller may be configured to compare an impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and adjust the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold when the impeller motor command is below the minimum command speed threshold, and equal to the maximum command speed threshold when the impeller motor command is above the maximum command speed threshold. In some embodiments, the minimum command speed threshold is 1,500 to 2,500 rpm. In some embodiments, the maximum command speed threshold is calculated each time a motor speed command is generated. In some embodiments, the maximum command speed threshold may be calculated based on at least one motor parameter. In some embodiments, the system may further include a motor temperature sensor configured to output a temperature data signal indicating the temperature of the impeller motor, and a power factor correction current monitoring circuit configured to output a PFC data signal indicating the current power factor correction current, and the maximum command speed threshold is calculated based on the temperature data signal and the PFC data signal. In some embodiments, the maximum command speed is set with a predetermined value as the upper limit. In some embodiments, the predetermined value may be 4,500 to 6,500 rpm. In some embodiments, the predetermined value may be 5,000 rpm. In some embodiments, the predetermined value may be about 2.5 times greater than the minimum command speed threshold.

[0094] According to another embodiment of the present disclosure, a method for controlling the rate of condensate accumulation in a distillation device may include providing a source fluid input to the distillation device. The method may further include evaporating at least a portion of the source fluid input into low-pressure vapor in an evaporator. The method may further include compressing low-pressure steam to high-pressure steam via an impeller. The method may further include condensing the high-pressure steam into condensate in a condenser and transferring heat from the high-pressure steam to an evaporator. The method may further include providing the controller with the level of condensate in the condenser, as sensed by a condensate level sensor. The method may further include using the controller to calculate a motor speed target based on the condensate level and a desired condensate level. The method may further include using the controller to control the rotational speed of the impeller by periodically generating impeller motor commands based on the last motor speed command, motor speed target, and speed command increment limit.

[0095] In some embodiments, the speed command increment limit is ≤10 rpm / sec. In some embodiments, the speed command increment limit is ≤5 rpm / sec. In some embodiments, the method may further include using a controller to compare an impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and adjusting the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold when the impeller motor command is below the minimum command speed threshold, and equal to the maximum command speed threshold when the impeller motor command is above the maximum command speed threshold. In some embodiments, the minimum command speed threshold may be 1,500 to 2,500 rpm. In some embodiments, the minimum command speed threshold may be 2,000 rpm. In some embodiments, the method may further include calculating the maximum command speed threshold each time a motor speed command is generated. In some embodiments, calculating the maximum command speed threshold may include calculating the maximum command speed threshold based on at least one motor parameter. In some embodiments, the method may further include providing the controller with a temperature data signal indicating the motor temperature from a motor temperature sensor and a power factor correction data signal indicating the current power factor correction current from a monitoring circuit. In some embodiments, the method may further include calculating a maximum command speed threshold based on the temperature data signal and the power factor correction data signal. In some embodiments, the method may further include setting a predetermined value as an upper limit for the maximum command speed threshold. In some embodiments, the predetermined value may be 4,500 to 6,500 rpm. In some embodiments, the predetermined value may be 5,000 rpm. In some embodiments, the predetermined value may be 2.5 times greater than or approximately that of the minimum command speed threshold.

[0096] According to one embodiment of the present disclosure, a fluid vapor distillation apparatus having first and second separable sections may include a source inlet that selectively communicates with a fluid source via at least one valve. The apparatus may further include a reservoir downstream of the source inlet. The apparatus may further include an evaporator having a plurality of tubes that communicate with the reservoir. The apparatus may further include a steam chamber coupled to the evaporator and communicating with a compressor. The apparatus may further include a condenser that communicates with the outlet of the compressor. The condenser may surround a plurality of tubes. The apparatus may further include a support plate that is rotatably coupled to a pivot and attached to the first section. The apparatus may further include a housing coupled to the second section via at least one mounting section. The first and second sections may be held together in a first state via one or more fasteners, and may be disconnected from each other in a second state in which the first section is rotatable about a pivot.

[0097] In some embodiments, at least one mounting section may be an isolated mounting section. In some embodiments, the first section may include a reservoir, an evaporator, and a condenser. In some embodiments, the second section may include a steam chamber and a condenser. In some embodiments, the pivot may include a biasing member. In some embodiments, the biasing member may be in a relaxed state when the first and second sections are in a first state, and in a compressed state when the first and second sections are in a second state. In some embodiments, the biasing member may have a relaxed state and an energy storage state. The support plate may have a displacement path between a first position when the biasing member is in a relaxed state and a second position when the biasing member is in an energy storage state. In some embodiments, the displacement path may be a linear displacement path. In some embodiments, the displacement path may be parallel to the axis of the pivot. In some embodiments, the biasing member may be a gas spring.

[0098] According to another embodiment of the present disclosure, the distillation apparatus may include a source fluid input that selectively fluidizes a source fluid reservoir via a set of fluid input valves. The apparatus may further include an evaporator that fluidizes the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. The apparatus may further include a condenser that fluidizes the compressor and is configured to convert the pressurized vapor from the compressor into a condensate. The apparatus may further include a condensate flow path and a concentrated flow path, each including separate first and second heat exchangers. The first and second heat exchangers may each include a heat exchange portion of the source fluid flow path from the source fluid reservoir. The heat exchange portion may be downstream of the source fluid input valves. The apparatus may further include a condensate temperature sensor configured to generate a data signal indicating the condensate temperature. The condensate temperature sensor may be located on the condensate flow path downstream of the first heat exchanger. The device may further include an output to a destination device. The device may further include a controller configured to actuate a set of input source valves based on a first multimodal control loop that generates a certain number of provisional total open state commands for all input source valves of the set of input source valves. The controller may be configured to actuate a set of input source valves based on a slider that generates a single total open state command from a number of provisional commands. The controller may be configured to actuate a set of input source valves based on a second control loop that receives a data signal and a requested temperature, distributes the total open state command among all input source valves, and adjusts the condensate temperature to a temperature setpoint.

[0099] In some embodiments, the heat exchange portions of the source fluid flow paths in the first and second heat exchangers may be arranged countercurrent to their respective condensate and concentrate flow paths. In some embodiments, the controller may be configured to operate in multiple operating states, and the temperature setpoint may be state-dependent. In some embodiments, the device further comprises a destination device that fluidically communicates with the condensate flow path via a point-of-use valve. In some embodiments, the destination device may be a medical system. In some embodiments, the medical system may be configured to mix at least one dialysate solution. In some embodiments, the destination device may be a dialysis machine. In some embodiments, the destination device may be a hemodialysis machine. In some embodiments, at least one of the first multimodal control loop and the second control loop may include a PID control loop. In some embodiments, the gain of at least one of the terms in the PID control loop may be zero. In some embodiments, the number of provisional total open state commands may be regulated by the output of at least one regulator control loop. In some embodiments, the distillation device may further comprise a water reservoir. The water reservoir may be located between the source input and the evaporator. One of at least one of the controller control loops may be configured to produce output based on a target reservoir temperature and the current reservoir temperature measured by a reservoir temperature sensor configured to generate a data signal representing the temperature of the fluid in the reservoir. In some embodiments, one of at least one of the controller control loops may be configured to produce output based on a target vapor temperature and the current vapor temperature measured by a vapor temperature sensor configured to generate a data signal representing the temperature of the vapor flow. In some embodiments, the device may further include a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level in the distillation device. The controller may be configured to determine the current blowdown rate from the concentrate level data signal.The first multimodal control loop may be configured to receive target blowdown rate and current blowdown rate data signals as inputs. In some embodiments, at least one of the provisional total open state commands may be a first production temperature state command, and at least one of the provisional total open state commands may be a second production temperature state command. In some embodiments, the device may further include an evaporator level sensor configured to output an evaporator data signal. The controller may be configured, at least in part, to generate at least one of the provisional total open state commands based on the inputs of the target evaporator sensor level and the evaporator data signal. In some embodiments, the target evaporator sensor level and the evaporator data signal may be input to a differential controller. In some embodiments, the differential controller may be a PID controller having a D-term gain that is at least one order of magnitude higher than the P and I terms.

[0100] According to another embodiment of the present disclosure, the steam distillation apparatus may include a reservoir having a source fluid input. The apparatus may further include an evaporator having a first side that is in fluid communication with the source fluid input via the reservoir, and a second side that is in fluid communication with a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into low-pressure steam and concentrate as the source fluid progresses toward the steam chamber. A non-uniform liquid level may exist in the evaporator during operation. The apparatus may further include an evaporator reservoir positioned laterally to the evaporator and in fluid communication with it via the reservoir. The evaporator reservoir may include a level sensor configured to monitor the level of the water column in the evaporator reservoir and generate a data signal indicating the level of the water column. The apparatus may further include a compressor having a low-pressure steam inlet that establishes fluid communication with the steam chamber and a high-pressure steam outlet that establishes fluid communication with a condenser via a condenser inlet. The apparatus may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with multiple external surfaces of the evaporator. The condenser may include a condensing section and a condensate accumulation section. The apparatus may further include a processor, which is configured in part to actuate a set of input source valves to the source fluid input based on data signals.

[0101] In some embodiments, the level sensor may include a displaceable member that is displaceable over a displacement range smaller than the height of the evaporator reservoir. In some embodiments, the level sensor may include a displaceable member that is displaceable over a displacement range extending from a first end portion of the evaporator reservoir to at least the midpoint of the evaporator reservoir. The displacement range may be a distance of less than 70% of the height of the evaporator reservoir. In some embodiments, the first end may be the furthest end of the evaporator reservoir from the water reservoir. In some embodiments, the evaporator reservoir may communicate with the steam chamber via a ventilation path extending from the first end portion of the evaporator reservoir. In some embodiments, the ventilation path may extend from the evaporator reservoir to a concentrate reservoir attached to and laterally positioned relative to the steam chamber. In some embodiments, the height of the evaporator reservoir may exceed the height of the evaporator. In some embodiments, the processor may be configured to determine the total open state time for a set of input source valves based in part on the current water column level determined via analysis of the target water column level and data signals. In some embodiments, the processor may be configured to determine the total open state time for a set of input source valves based in part on the output of a PID controller that receives a target water column level and the current water column level as inputs. In some embodiments, the gain for at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain for the D term of the PID controller may be at least one order of magnitude higher than the gains for the P and I terms of the PID controller. In some embodiments, the gain for the D term of the PID controller may be two orders of magnitude higher than the gains for the P and I terms of the PID controller. In some embodiments, the processor may be configured to determine the total open state time based in part on a target blowdown rate and the current blowdown rate, such as indicated by a blowdown level data signal produced by a blowdown level sensor in a blowdown reservoir mounted in the steam chamber.In some embodiments, the processor may be configured to determine a total open state command, in part, based on the output of at least one controller control loop. In some embodiments, one of the at least one controller control loop may be configured to produce an output based on a target reservoir temperature and the current reservoir temperature measured by a reservoir temperature sensor, which is configured to generate a data signal representing the temperature of the fluid in the reservoir. In some embodiments, one of the at least one controller control loop may be configured to produce an output based on a target steam temperature and the current steam temperature measured by a steam temperature sensor, which is configured to generate a data signal representing the temperature of the steam flow. In some embodiments, the controller may be configured to modify a total open state command for a set of input source valves in response to a change in the water column level indicated by a data signal. In some embodiments, the controller may be configured to modify a total open state command for a set of input source valves in proportion to the rate of change in the water column, as indicated by a data signal.

[0102] According to another embodiment of the present disclosure, a method for controlling the flow of a source fluid into a distillation device may include establishing a non-uniform liquid level in the evaporator of the distillation device by boiling the liquid in the distillation device. The method may further include using a first level sensor to sense the liquid column level in an evaporator reservoir, which is in fluid communication with the evaporator and positioned at the same height as the evaporator. The method may further include using a second level sensor to sense the concentrate level in a concentrate reservoir, which is in fluid communication with the evaporator. The method may further include using a processor to generate a source inlet valve open time command, at least in part, based on the concentrate level and the target concentrate accumulation rate, as well as the delta between the liquid column level and the target liquid column level. The method may further include commanding a number of source inlet valves to open based on the source inlet valve open time command.

[0103] In some embodiments, sensing the liquid column level may include displacing a displaceable member over a displacement range smaller than the height of the evaporator reservoir. In some embodiments, sensing the liquid column level may include displacing a displaceable member over a displacement range extending from a first end portion of the evaporator reservoir to at least the midpoint of the evaporator reservoir. The displacement range may be a distance of less than 70% of the height of the evaporator reservoir. In some embodiments, the first end may be the furthest end of the evaporator reservoir of the water reservoir of the distillation device. In some embodiments, the method may further include venting from the evaporator reservoir through a vent path into the vapor chamber of the distillation device located above the evaporator. In some embodiments, the vent path may extend from the evaporator reservoir to a concentrate reservoir attached to and laterally positioned to the vapor chamber. In some embodiments, generating a source inlet valve open time command may include inputting a delta to a PID controller. In some embodiments, the gain for at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain for the D term of the PID controller may be at least one order of magnitude higher than the gains for the P and I terms of the PID controller. In some embodiments, the gain for the D term of the PID controller may exceed the gains for the P and I terms of the PID controller by more than two orders of magnitude. In some embodiments, generating a source inlet valve open time command may include determining the current concentrate accumulation rate from the concentrate level and calculating the delta between the target concentrate rate and the current concentrate accumulation rate. In some embodiments, generating a source inlet valve open time command may include generating an output for at least one regulator control loop. In some embodiments, the method may further include sensing the current reservoir temperature using a reservoir temperature sensor, and generating an output for at least one regulator control loop may include producing an output based on the target reservoir temperature and the current reservoir temperature. In some embodiments, the method may further include sensing the temperature of the vapor flow in the distillation device using a vapor temperature sensor. In some embodiments, generating an output for at least one regulator controller may include producing an output based on the target vapor temperature and the current vapor temperature. In some embodiments, the method may further include modifying the source inlet valve open time command in response to a change in the liquid column level. In some embodiments, the method may further include modifying the source inlet valve opening time command in proportion to the rate of change of the liquid column level.

[0104] According to another embodiment of the present disclosure, the fluid vapor distillation apparatus may comprise at least one controller. The apparatus may further comprise a source inlet that selectively communicates with a fluid source via at least one valve. The apparatus may further comprise an evaporator that communicates with the source inlet. The apparatus may further comprise a steam chamber coupled to the evaporator and communicating with a compressor. The external surface of the steam chamber may form part of the inlet flow path to the compressor and part of the outlet flow path to the compressor outlet. The apparatus may further comprise a concentrate reservoir. The concentrate reservoir may be mounted to the steam chamber via an inlet path and positioned laterally to the steam chamber such that at least a portion of the concentrate reservoir is at the same height as the steam chamber. The apparatus may further include a condenser that is in fluid communication with the compressor outlet via a linear flow path. The linear flow path may include a condenser inlet fixed to a sheet, having a first surface defining a portion of the steam chamber and an opposing surface defining a portion of the condenser. The apparatus may further include a product process flow reservoir coupled to the condenser by a product reservoir inlet and positioned laterally to the condenser, such that at least a portion of the product process flow reservoir is at the same height as the condenser.

[0105] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a wall extending into the concentrate reservoir at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate reservoir and divide the concentrate reservoir into a first part and a second shielded part. In some embodiments, the obstruction may include at least one vent port. In some embodiments, the product reservoir inlet may be adjacent to the product accumulation surface of the condenser. In some embodiments, the compressor may be driven by a motor located in a receiving well that is partially fitted into the side of the steam chamber. In some embodiments, the compressor may include an impeller that extends laterally relative to the steam chamber and rotates about an axis parallel to the longitudinal axis of the steam chamber.

[0106] According to another embodiment of the present disclosure, the distillation apparatus may include a source fluid input that selectively communicates with a source via a set of fluid input valves. The apparatus may further include an evaporator that communicates with a compressor having an impeller that is fluidly connected to the source input and operably coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid progresses toward the compressor. The device may further include a condenser that is in heat transfer relationship with multiple external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the multiple external surfaces of the evaporator. The device may further include a concentrate level sensor configured to sense the current level of concentrate in a concentrate reservoir, which has an inflow path and a long axis extending parallel to the evaporator, and is located above the evaporator. The device may further include at least one controller configured to control the rotational speed of the impeller in the low-temperature and high-temperature distillate production states by periodically generating an impeller motor command based on a nominal low-temperature distillate production speed command in the low-temperature distillate production state and a nominal high-temperature distillate production speed command in the high-temperature distillate production state. The nominal low-temperature distillate production speed command may be a motor speed command that is faster than the nominal high-temperature distillate production speed command.

[0107] In some embodiments, adjustments to the impeller motor command may be made based on a data signal from a concentrate level sensor indicating the level of concentrate in the concentrate reservoir. In some embodiments, the adjustment may be limited by an impeller motor command increment limit. In some embodiments, the impeller motor command increment limit may be ≤10 rpm / sec. In some embodiments, the impeller motor command increment limit may be ≤5 rpm / sec. In some embodiments, the impeller motor command may be decremented when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds a first threshold. In some embodiments, the first threshold may be defined as a concentrate level where the concentrate reservoir is 65-80% full. In some embodiments, the impeller motor command may be held below a previously commanded impeller motor command value when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds the first threshold. In some embodiments, the first threshold may be defined as a concentrate level where the concentrate reservoir is 65-80% full. In some embodiments, the impeller motor command may be incremented when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds a second threshold. In some embodiments, the nominal high-temperature distillate production speed command may be a calibration value defined during production. In some embodiments, the nominal high-temperature distillate production speed command may be less than 80% of the nominal low-temperature distillate production speed command and greater than 70% of the nominal low-temperature distillate production speed command. In some embodiments, the nominal low-temperature distillate production speed command may be 4,500 rpm.

[0108] According to another embodiment of the present disclosure, a method for controlling the compressor of a distillation device may include opening at least one fluid inlet valve to deliver source fluid from a fluid source into the reservoir of the distillation device. The method may further include converting the source fluid into a concentrated flow and a vapor flow in the evaporator. The method may further include using a processor to determine a state-specific compressor speed command. The compressor speed command may be based on a nominal low-temperature distillate production speed command in a low-temperature distillate production state and on a nominal high-temperature distillate production speed command in a high-temperature distillate production state. The nominal low-temperature distillate production speed command may be a motor speed command that is faster than the nominal high-temperature distillate production speed command. The method may further include using a processor to generate a final command speed based on the compressor speed command. The method may further include using a processor to command the rotation of the compressor impeller at the final command speed. The method may further include compressing the vapor flow through the compressor. The method may further include condensing the vapor flow into a condensate as the vapor flow condenses and transferring heat to the evaporator.

[0109] In some embodiments, the method may further include using a level sensor to sense the level of concentrate in a concentrate reservoir that is in fluid communication with the evaporator. In some embodiments, generating the final command speed may include determining an adjustment to the compressor speed command based on the concentrate level. In some embodiments, determining an adjustment may include decrementing the compressor speed command when the concentrate level exceeds a first threshold. In some embodiments, the first threshold may be defined as the concentrate level at which the concentrate reservoir is 65-80% full. In some embodiments, determining an adjustment may include keeping the final command speed at or below a previously commanded final command speed when the concentrate level exceeds the first threshold. In some embodiments, determining an adjustment may include decrementing the compressor speed command when the concentrate level exceeds a second threshold. In some embodiments, generating the final command speed may include determining an adjustment to the compressor speed command. In some embodiments, the adjustment may be limited by an increment limit. In some embodiments, the increment limit may be ≤10 rpm / sec. In some embodiments, the increment limit may be ≤5 rpm / second. In some embodiments, the nominal high-temperature distillate production rate command may be a calibration value defined during production. In some embodiments, the nominal high-temperature distillate production rate command may be less than 80% of the nominal low-temperature distillate production rate command and greater than 70% of the nominal low-temperature distillate production rate command. In some embodiments, the nominal low-temperature distillate production rate command may be 4,500 rpm.

[0110] According to another embodiment of the present disclosure, the distillation apparatus may include a reservoir that selectively communicates with a source via a set of fluid input valves. The apparatus may further include in the reservoir at least one heating element and at least one reservoir temperature sensor. The reservoir temperature sensor may be configured to generate a reservoir temperature data signal. The apparatus may further include an evaporator having a first side that communicates with the reservoir and a second side that communicates with a compressor having an impeller operably coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor flow and concentrate as the source fluid progresses toward the vapor chamber. The apparatus may further include a condenser that is in heat transfer relationship with a plurality of external surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator. The device may further include a concentrate level sensor configured to sense the current level of concentrate in a concentrate reservoir, which has an inflow path and a long axis extending parallel to the evaporator, and is located above the evaporator. The device may further include a steam temperature sensor located in the flow path of the steam flow and configured to generate a steam temperature data signal. The device may further include at least one controller configured to determine a duty cycle command for at least one heating element. The duty cycle command may be at least in part based on a target temperature of the steam flow, a steam temperature data signal, a reservoir temperature data signal, and a total source open command for a set of fluid inlet valves.

[0111] In some embodiments, the target temperature of the vapor flow may be 108°C. In some embodiments, the controller may be configured to adjust the duty cycle command to match at least one limit. In some embodiments, the limit may be a maximum power consumption limit. In some embodiments, the controller may be configured to adjust the duty cycle command at least partially based on the compressor's power consumption. In some embodiments, the controller may be configured to determine the compressor's power consumption and calculate the limit for the duty cycle command by subtracting the compressor's power consumption from a predefined power value. In some embodiments, the predefined power value may be defined as the maximum total power for the system. In some embodiments, the duty cycle command may be limited to a pre-determined maximum duty cycle. In some embodiments, the predefined maximum duty cycle may be 90% duty cycle or less. In some embodiments, the target temperature of the vapor flow may be state-specific. In some embodiments, the target temperature in the low-temperature distillate production state may be higher than the target temperature in the high-temperature distillate production state. In some embodiments, the target temperature of the vapor flow in the first state may be 108°C, and the target temperature of the vapor flow in the second state may be 104°C. In some embodiments, the target temperature in the first state may be 4°C higher than the target temperature in the second state. In some embodiments, the target temperature in the first state may be at least 95% of the target temperature in the second state, but less than the target temperature in the second state. In some embodiments, the controller may be configured to determine a feedforward term used to determine the duty cycle command based on a total source open command for a set of fluid input valves and at least one thermodynamic characteristic of the source fluid. In some embodiments, the thermodynamic characteristic may be the specific heat of the source fluid. In some embodiments, the target temperature of the vapor flow may be 111-112°C.

[0112] According to one embodiment of the present disclosure, a method for heating a fluid in a distillation device may include opening at least one fluid input valve to deliver a source fluid from a fluid source into a reservoir of the distillation device. The method may further include sensing the reservoir temperature of the source fluid in the reservoir via a temperature sensor. The method may further include sensing the vapor temperature of a vapor stream generated from the source fluid. The method may further include comparing the vapor temperature with a target vapor temperature using a processor. The method may further include inputting a delta between the vapor temperature and the target vapor temperature to a first controller to generate a first controller output. The method may further include providing input to a second controller, at least partially based on the first controller output and the reservoir temperature, to generate a second controller output. The method may further include modifying the second controller output to a modified second controller output based on the total open state time of at least one fluid input valve. The method may further include commanding a duty cycle for the heating element in the reservoir based on the modified second controller output and at least one limit.

[0113] In some embodiments, the target vapor temperature may be in the range of 108°C to 112°C. In some embodiments, at least one limit may include a maximum power consumption limit. In some embodiments, at least one limit may include a limit based at least partially on the power consumption of a compressor in the distillation device. In some embodiments, the method may further include determining the power consumption of the compressor and calculating the limit of at least one limit by subtracting the compressor's power consumption from a predefined power value. In some embodiments, the predefined power value may be defined as the maximum total power for the system. In some embodiments, at least one limit may include a predefined maximum duty cycle limit. In some embodiments, the predefined maximum duty cycle may be 90% duty cycle or less. In some embodiments, the target vapor temperature of the vapor flow may be state-specific. In some embodiments, the target temperature in the low-temperature distillate production state may be higher than the target temperature in the high-temperature distillate production state. In some embodiments, the target temperature in the first state may be 4°C higher than the target temperature in the second state. In some embodiments, the target temperature in the first state may be at least 95% of the target temperature in the second state, but less than the target temperature in the second state. In some embodiments, the second controller output to the modified second controller output may include determining a feedforward term based on a total source open command of at least one fluid input valve and at least one thermodynamic characteristic of the source fluid. In some embodiments, the thermodynamic characteristic may be the specific heat of the source fluid.

[0114] According to one embodiment of the present disclosure, a water distillation device may include a reservoir that selectively communicates with a fluid source via a set of source constant ratio valves. The device may further include an evaporator that communicates with the reservoir. The device may further include a steam chamber coupled to the evaporator and communicating with a compressor. The device may further include a concentrate reservoir having a concentrate level sensor attached to the steam chamber via an inlet path and configured to generate a concentrate level data signal indicating the fill percentage of the concentrate reservoir. The concentrate reservoir may be coupled to a concentrate flow path. The device may further include a condenser coupled to the outlet of the compressor and communicating with the condensate flow path. The device may further include first and second heat exchangers, including a heat exchange portion of the source fluid flow path from the fluid source. The heat exchange portion of the first heat exchanger may be in a heat exchange relationship with the condensate flow path, and the heat exchange portion of the second heat exchanger may be in a heat exchange relationship with the concentrate flow path. The heat exchange portion of the source fluid flow path may be located downstream of the source constant valve. The device may further include at least one distillate sensor communicating with a condensate flow path located downstream of the first heat exchanger. The device may further include a controller configured, at least in part, to determine the total open state time of the source constant valve based on concentrate data signals and a target concentrate ratio. The controller may be configured to allocate a percentage of the total open state command to each of the source constant valves based on at least one distillate sensor data signal from at least one distillate sensor.

[0115] In some embodiments, the condenser may include a condensing section and a condensate accumulation section. In some embodiments, the condenser may be in fluid communication with a condensate reservoir, including a condensate level sensor configured to monitor the level of condensate in the condensate reservoir and generate a condensate data signal indicating the fill percentage of the condensate storage area. The condensate reservoir may be located between the condenser and the concentrate flow path. In some embodiments, the controller may be configured to maintain the target fill percentage of the condensate storage area based on the output of a PID control loop that uses a target fill percentage and a delta between the target fill percentage and the current fill percentage, as indicated by the condensate data signal, as inputs. In some embodiments, the target fill percentage is at least equivalent to 1 liter and may be less than 2 liters. In some embodiments, the condenser may be in fluid communication with a condensate reservoir, including a condensate level sensor configured to monitor the level of condensate in the condensate reservoir and generate a condensate data signal indicating the fill percentage of the condensate reservoir. The condensate reservoir is located between the condenser and the concentrate flow path. In some embodiments, at least one distillate sensor may include a temperature sensor. In some embodiments, at least one distillate sensor data signal may be a temperature data signal indicating the current condensate temperature after passing through a heat exchanger. In some embodiments, the controller may be configured to distribute a percentage of the total open state command to each of the source-control valves based on a control loop that uses the target condensate temperature and the current condensate temperature as inputs. In some embodiments, the target temperature is at least 35°C, but may be 40°C or less. In some embodiments, the target temperature is at least 20°C, but may be 30°C or less.

[0116] According to another embodiment of the present disclosure, the distillation system may include a distillation device that selectively fluidizes a fluid source via a set of source constant ratio valves. The distillation device may have a concentrate output coupled to a concentrate flow path, and may have a condensate output coupled to a condensate flow path. The system may further include first and second heat exchangers, including a heat exchange portion of a source fluid flow path from a fluid source downstream of the source constant ratio valves. The heat exchange portion of the first heat exchanger may be in a heat exchange relationship with a condensate flow path, and the heat exchange portion of the second heat exchanger may be in a heat exchange relationship with a concentrate flow path. A dedicated source constant ratio valve may be present for each heat exchanger. The system may further include a condensate sensor assembly that communicates with a condensate flow path at a point downstream of the first heat exchanger. The system may further include a controller configured, in a first operating state, to divert the commanded flow of source fluid from a fluid source between source constant valves based on a first target temperature and a delta between the first target temperature and the current concentrate temperature received by the controller from a condensate sensor assembly. In a second operating mode, the controller may be configured to distribute the entire commanded flow to a source constant valve dedicated to a second heat exchanger and to open the source constant valve dedicated to the first heat exchanger for a duty cycle which may be below a predefined limit.

[0117] In some embodiments, the predefined limit may be 5%. In some embodiments, the predefined limit may be 2%. In some embodiments, the condensate sensor assembly may include redundant temperature sensors. In some embodiments, the first and second heat exchangers may be helical and formed by winding the heat exchangers around the outside of the distillation device. In some embodiments, the first operating state may be a low-temperature distillate production state, and the second operating state may be a high-temperature distillate production state. In some embodiments, the first target temperature is at least 35°C but may be 40°C or less. In some embodiments, the controller may be configured to open a source constant ratio valve dedicated to the first heat exchanger in the second operating state based on the second target temperature and the delta between the second target temperature and the current concentrate temperature. In some embodiments, the second target temperature may be at least 65°C higher than the first target temperature. In some embodiments, the second target temperature may be at least 50°C higher than the first target temperature. In some embodiments, the second target temperature may be above 95°C and below 100°C. In some embodiments, the second target temperature may be 96°C. In some embodiments, the second target temperature may be at least twice the first target temperature. In some embodiments, the second target temperature may be at least 2.5 times the first target temperature. In some embodiments, the second target temperature may be at least 3.5 times the first target temperature. In some embodiments, the system may further include an evaporator level sensor located in the evaporator reservoir, which is in fluid communication with the evaporator of the distillation device. The controller may be configured, at least partially, to determine the total flow command based on an evaporator level data signal indicating the level of the water column in the evaporator reservoir in the second operating state. In some embodiments, the first target temperature is at least 20°C, but may be 30°C or less. In some embodiments, the first target temperature is 25°C.

[0118] According to another embodiment of the present disclosure, a method for controlling and distributing the flow of a source fluid into a distillation device may include sensing the concentrate level in a concentrate reservoir, which is in fluid communication with the evaporator of the distillation device, using a concentrate level sensor. The method may further include sensing the temperature of the product fluid produced by the distillation device at a point downstream of a product heat exchanger, which is positioned in a heat exchange relationship with the inflow source fluid. The method may further include determining the concentrate accumulation rate based on the concentrate level using a processor. The method may further include calculating a first delta between the concentrate accumulation rate and a first target concentrate accumulation rate and a second delta between the concentrate accumulation rate and a second target concentrate accumulation rate using a processor. The method may further include determining a first and second provisional open state command and a second provisional open state command with respect to first and second source inflow constant ratio valves using a processor. The first provisional open state command may be based on the first delta, and the second provisional open state command may be based on the second delta. The method may further include using a processor to calculate the final open state command from the provisional open state time command. The method may further include using a processor to split the final open state command between a first source inlet constant ratio valve and a second inlet constant ratio valve in the first operating state. The first source inlet constant ratio valve may be connected to a product heat exchanger. The split may be based on the delta between the target production temperature and the temperature of the product fluid. The method may further include using a processor to distribute the entire final open state command to a second source inlet constant ratio valve in the second operating state. The method may further include using a processor to open the first source inlet constant ratio valve in the second operating state via a command from the processor for a duty cycle below a predefined limit.

[0119] In some embodiments, the first target accumulation rate may exceed the second target accumulation rate. In some embodiments, calculating the final open state command may include inputting a first provisional open state command and a second provisional open state command to the slider. In some embodiments, calculating the final open state command may include generating a hybrid command from first and second provisional source open state commands. In some embodiments, calculating the final open state command may include determining a first state fraction and a second state fraction, multiplying the first provisional open state command by the first state fraction, and multiplying the second provisional open state command by the second state fraction. In some embodiments, calculating the final open state command includes adjusting the command mainly from the first provisional open state command to mainly the second provisional open state command during the transition between the first and second operating states. In some embodiments, calculating the final open state command may include adjusting the command entirely from the first provisional open state command to entirely the second provisional open state command during the transition between the first and second operating states. In some embodiments, the second operating state may be a high-temperature distillate production state. In some embodiments, the division may include determining an open state command for a first source inlet constant ratio valve based on the delta between the target product temperature and the product fluid temperature, and determining an open state command for a second source inlet constant ratio valve by subtracting the open state command from the first source inlet constant ratio valve from the final open state command. In some embodiments, the predefined limit may be less than 5%. In some embodiments, the predefined limit may be less than 2%. In some embodiments, determining the second provisional open state command may further include sensing the level of the liquid column in the evaporator reservoir, which is in fluid communication with the evaporator, using an evaporator level sensor. The second provisional open state command may be based in part on the delta between the liquid column level and the target level of the liquid column. In some embodiments, the second provisional open state command may be based on the rate of change of the delta between the liquid column level and the target level of the liquid column.

[0120] According to one embodiment of the present disclosure, the medical system may comprise at least one concentrate fluid. The system may further comprise a distillation device having an evaporator, a condenser, and a purified product water heat exchanger having a source fluid flow path and a purified product water flow path in a heat exchange relationship with each other. The system may further comprise a medical treatment device, which may comprise a treatment fluid preparation circuit that selectively fluidizes the purified product water flow path via a point-of-use valve. The medical treatment device may comprise a treatment device processor configured to command a mixture of at least one concentrate and purified water and generate a prescribed treatment fluid using the treatment fluid preparation circuit. The system may further comprise a communication link between the treatment device processor of the medical treatment device and the distillation device processor of the distillation device. The medical treatment device processor may be configured to transmit mode commands to the distillation device processor. The system may further comprise a sensor assembly communicating with the purified product water flow path. The system may further comprise a source valve intermediate between the fluid source and the source fluid flow path. The distillation device processor may be configured, at least in part, to actuate the source valve based on mode commands and data from the sensor assembly.

[0121] In some embodiments, the sensor assembly may include at least one temperature sensor and at least one conductive sensor. In some embodiments, the distillation device processor may be configured at least partially to actuate the source valve based on a mode command and temperature data from the sensor assembly. In some embodiments, the distillation device processor may be configured at least partially to actuate the source valve based on a mode command, data from the sensor assembly, and a target setpoint for purified water. In some embodiments, the target setpoint may be a temperature setpoint. In some embodiments, the target setpoint may be determined by the distillation device processor based on a mode command. In some embodiments, the target setpoint may be based on a first mode command, which may be in the range of 20 to 30°C, and the target setpoint may be based on a second mode command, which may be above 90°C.

[0122] In some embodiments, the medical treatment device may be a dialysis machine. In some embodiments, the medical treatment device may be a hemodialysis device. In some embodiments, the treatment fluid may be a dialysis fluid. In some embodiments, the condenser may include a condensation section and a product storage section. The product storage section may have a volume of at least 1 liter. In some embodiments, the distillation device processor may further be configured, at least in part, to control the operation of the compressor motor of the distillation device based on a mode command. In some embodiments, the distillation device processor may further be configured, at least in part, to control the operation of the concentrate outlet valve of the distillation device based on a mode command.

[0123] According to one embodiment of the present disclosure, a medical system may include a distillation device having an evaporator, a source input flow path to a source inlet that is in fluid communication with the evaporator, a condenser, and a purified product water output flow path that is in fluid communication with the condenser. The system may further include first and second filters in the source inlet flow path. The system may further include a plurality of pressure sensors, including a first pressure sensor upstream of the first filter and a second pressure sensor downstream of the second filter. The system may further include a medical treatment device, which includes a treatment fluid preparation circuit that selectively communicates with the purified product water output flow path via a point-of-use valve. The system may further include a communication link between a medical treatment device processor and a distillation device processor of the distillation device. The distillation device processor may be configured to perform a first filter replacement check based on data from the plurality of pressure sensors, and the medical device processor may perform a second filter replacement check, and if either the first or second filter replacement check fails, it may be configured to command the distillation device processor via the communication link to enter filter replacement mode.

[0124] In some embodiments, the second filter replacement check may include checking the number of days elapsed since the installation of the first and second filters against a limit. In some embodiments, the medical treatment device may include a graphical user interface. In some embodiments, the second filter replacement check may include checking user input on the graphical user interface against at least one predefined criterion. In some embodiments, the system may further include a sampling port located between the first and second filters, where the predefined criterion may be a water chemical properties test specimen criterion. In some embodiments, the water chemical properties test specimen criterion may be a chlorine treatment level criterion. In some embodiments, the distillation device processor may be configured to command cleaning of the first and second filters prior to at least one of the first or second filter replacement checks. In some embodiments, the distillation device processor may be configured to perform the first filter replacement check based on a filter output pressure data signal from a second pressure sensor. In some embodiments, the distillation device processor may be configured to indicate a failure of the first filter replacement check when the filter output pressure falls below a threshold. In some embodiments, the distillation device processor may be configured to perform a first filter replacement check based on a delta between the pressures upstream of the first and second filters, as indicated by a first pressure sensor, and the pressures downstream of the first and second filters, as indicated by a second pressure sensor. In some embodiments, the distillation device processor may be configured to indicate a failure of the first filter replacement check when the delta is below a threshold.

[0125] According to another embodiment of the present disclosure, the medical system may include a distillation device having a source water input and a fluid output flow path. The system may further include a medical treatment device including a plurality of fluid flow paths, a plurality of valves, at least one fluid pump, and a fluid inlet that selectively communicates with the fluid output flow path via a point-of-use valve. The system may further include a communication link between the medical treatment device and the distillation device. The system may further include a sensor assembly communicating with the fluid output flow path. The system may further include a treatment device processor configured to actuate a plurality of valves and at least one fluid pump to pump high-temperature fluid through a plurality of fluid flow paths. The system may further include a distillation device processor configured to control the operation of a distillation device based on at least one data signal from a sensor assembly and a mode command transmitted from a medical device processor of a medical treatment device via a communication link, and to produce and output high-temperature fluid to a fluid output flow path between a first cycle in which the distillation device processor commands the point-of-use valve to be opened and a second cycle in which the distillation device processor commands the point-of-use valve to be closed and the valve to a flow path communicating with the fluid output flow path to be opened.

[0126] In some embodiments, the source water input may be in fluid communication with a temperature-uncontrolled fluid source. In some embodiments, the medical treatment device may be a dialysis machine. In some embodiments, the medical treatment device may be a hemodialysis machine. In some embodiments, the fluid flow paths may include a first flow path and a second flow path, separated from each other by a semipermeable membrane. In some embodiments, the fluid flow paths may be contained within at least a blood pumping cassette and a dialysate pumping cassette. In some embodiments, the medical treatment device may include a fluid reservoir, and the treatment device processor may be configured to send a signal to the distillation device processor to terminate the first cycle based on the amount of high-temperature fluid contained in the fluid reservoir. In some embodiments, the medical treatment device may include a heater. In some embodiments, at least one data signal may include at least one temperature data signal. In some embodiments, the distillation device may include a compressor, and the distillation device processor may be configured to control the operation of the compressor via a compressor speed command determined partly based on a mode command. In some embodiments, the distillation device processor may be configured to control the operation of the distillation device based on at least one data signal and another mode command transmitted from the therapeutic device processor via a communication link, to produce a medical therapeutic fluid component and output it to a fluid output flow path. In some embodiments, the multiple flow paths may comprise a medical therapeutic fluid mixing circuit, and the therapeutic device processor may be configured to command the operation of at least one pump and multiple valves to mix the medical therapeutic fluid component with at least one concentrate that fluid-communicates with the multiple flow paths according to a predetermined prescription.

[0127] Details of one or more embodiments are described in the accompanying drawings and the following description. Other features and advantages will be evident from the description, drawings, and claims. This specification also provides, for example, the following items: (Item 1) A steam distillation system for providing a distillate at a controlled temperature, wherein the steam distillation system is A steam distillation apparatus is provided, configured to receive a certain volume of source water from a fluid source and produce a distillate. The device described above, A concentrate flow path equipped with concentrate output, A distillate flow path equipped with a distillate output, At least one Gensadahiben, A first heat exchanger comprising at least a portion of the aforementioned distillate flow path, A second heat exchanger comprising at least a portion of the aforementioned concentrated fluid flow path, wherein the first heat exchanger and the second heat exchanger are in fluid flow communication with the fluid source, A distillate sensor assembly, which communicates with the distillate flow path and is located downstream of the first heat exchanger, is configured to generate a distillate temperature measurement value. A controller configured to control the aforementioned valve and Equipped with, The aforementioned controller, Receiving the aforementioned distillate temperature measurement, To determine the difference between the first target temperature and the measured distillate temperature, Based on the difference between the first target temperature and the measured distillate temperature, the source water from the fluid source is divided between the first heat exchanger and the second heat exchanger. A steam distillation system configured to perform the following: (Item 2) The controller further, To determine the total source ratio duty cycle, Based on the aforementioned total source constant ratio valve duty cycle, the volume of source water received by the steam distillation device is controlled. The system described in item 1, configured to perform the following actions. (Item 3) The aforementioned system further, Concentrated reservoir, Concentrate level sensor and Equipped with, The system according to item 2, wherein the controller is configured to determine the total source constant ratio valve duty cycle based on the concentrate accumulation rate and target concentrate accumulation rate calculated from the level measurement output of the concentrate level sensor. (Item 4) The system according to item 2, wherein the controller is configured to control the at least one source constant valve in a second operating mode such that it allocates all of the total source constant valve duty cycles that control the flow of source water to the second heat exchanger to the at least one source constant valve, and opens the at least one source constant valve that controls the flow of source water to the first heat exchanger for an additional duty cycle below a predefined limit. (Item 5) The aforementioned predefined limits are selected from a list consisting of 5%, 2%, less than 2%, and zero, as described in item 4 of the system. (Item 6) The system described in item 4, wherein the first operating mode is a low-temperature distillate production state, and the second operating mode is a high-temperature distillate production state. (Item 7) The system according to item 4, wherein the controller is configured to open at least one source control valve that controls the source water to the first heat exchanger based on a second target temperature and the difference between the second target temperature and the concentrate temperature in the second operating state. (Item 8) The system according to item 7, wherein the second target temperature is at least 65°C higher than the first target temperature. (Item 9) The system according to item 7, wherein the second target temperature is at least 50°C higher than the first target temperature. (Item 10) The system described in item 7, wherein the second target temperature is above 95°C and below 100°C. (Item 11) The system described in item 7, wherein the second target temperature is 96°C. (Item 12) The system according to item 7, wherein the second target temperature is at least twice the first target temperature. (Item 13) The system according to item 7, wherein the second target temperature is at least 2.5 times the first target temperature. (Item 14) The system according to item 7, wherein the second target temperature is at least 3.5 times the first target temperature. (Item 15) The steam distillation apparatus further, Evaporator and, The evaporator reservoir is in fluid communication with the evaporator, An evaporator level sensor is disposed within the evaporator reservoir, the evaporator level sensor communicates with the controller, and the evaporator level sensor transmits a data signal to the controller that provides the level of the water column in the evaporator reservoir. Equipped with, The system according to item 1, wherein in the second mode, the controller is configured to determine the total source constant ratio valve duty cycle based at least in part on the evaporator level data signal indicating the level of the water column in the evaporator reservoir. (Item 16) The system according to item 1, wherein the first target temperature is at least 20°C but 25°C or less. (Item 17) The system according to item 1, further comprising a source fluid temperature sensor communicating with the controller, the source fluid temperature sensor providing the controller with data relating to the source fluid temperature measurement, and the controller configured to determine the first target temperature, at least in part, based on the source fluid temperature measurement received from the source fluid temperature sensor. (Item 18) The system according to item 1, further comprising a concentrate sensor assembly configured to communicate with the concentrate flow path downstream of the portion of the concentrate flow path contained within the second heat exchanger and to generate concentrate temperature measurements. (Item 19) The system according to item 18, wherein the controller is configured to open at least one source control valve that controls the source water to the second heat exchanger based at least partially on the difference between a third target temperature and the concentrated temperature measurement. (Item 20) The system according to item 19, wherein the third target temperature is the historical average of the concentrate temperature. (Item 21) The system according to item 1, wherein the controller is configured to open at least one source control valve that controls the source water to the second heat exchanger, at least partially, based on a minimum limit. (Item 22) The system according to item 21, wherein the minimum limit exceeds a predefined duty cycle or a predefined percentage of the combined duty cycle for all of the source-fixed ratio valves. (Item 23) The system described in item 1, wherein the controller is located in an electronics box and is in a heat transfer relationship with the flow path from the source water that leads to the second heat exchange. (Item 24) The system according to item 23, wherein the controller is configured, at least in part, to determine an electronics box cooling duty cycle command based on an electronics box cooling duty cycle command and to open at least one source control valve that controls the source water to the second heat exchanger. (Item 25) The distillate sensor assembly comprises a redundant temperature sensor, as described in item 1. (Item 26) The distillate sensor assembly comprises a redundant temperature sensor and a redundant conductivity sensor, as described in item 1. (Item 27) The system according to item 1, wherein the first and second heat exchangers are helical and are formed by winding the heat exchangers around the outside of the distillation device. (Item 28) A fluid vapor distillation apparatus, At least one controller, A source inlet and a fluid source selectively communicate with each other via at least one valve, An evaporator that is in fluid communication with the aforementioned source inlet, A steam chamber, coupled to the evaporator and in fluid communication with the compressor, A concentrate reservoir, the concentrate reservoir being attached to the steam chamber via an inflow path and positioned laterally to the steam chamber, such that at least a portion of the concentrate reservoir is at the same height as the steam chamber; A condenser that communicates fluid with the outlet of the compressor via a linear flow path, the linear flow path including a condenser inlet having a windowed compartment with a plurality of openings, the openings establishing a flow path from the condenser inlet to the condenser, and At least a portion of the product process flow reservoir is at the same height as the condenser, and the product process flow reservoir is connected to the condenser by the product reservoir inlet and positioned laterally to the condenser. A device equipped with the following features. (Item 29) The aforementioned inflow path includes the apparatus described in item 28, including obstacles. (Item 30) The apparatus according to item 29, comprising a plate having a compartment that extends into the concentrate reservoir at an angle substantially perpendicular to the inflow path. (Item 31) The apparatus according to item 29, wherein the obstruction extends into the concentrate reservoir, dividing the concentrate reservoir into a first portion and a second shielding portion. (Item 31) The apparatus according to item 28, further comprising a ventilation path extending from the concentrate reservoir to the steam chamber, wherein the ventilation path extends substantially parallel to the inflow path with respect to gravity and is located above it. (Item 32) The apparatus described in item 28, wherein the product reservoir inlet is adjacent to the product accumulation surface of the condenser. (Item 33) The compressor is the device according to item 28, which is driven by a motor and is mounted in a receiving well that is fitted into the side of the steam chamber. (Item 34) The apparatus according to item 28, wherein the compressor includes an impeller that passes through at least a portion of the steam chamber and rotates about an axis that is offset from but parallel to the center of the longitudinal axis of the steam chamber. (Item 35) A fluid vapor distillation apparatus having first and second separable sections, A source inlet and a fluid source selectively communicate with each other via at least one valve, The reservoir downstream of the aforementioned source inlet, An evaporator having a plurality of tubes that are in fluid communication with the water reservoir, A steam chamber, coupled to the evaporator and in fluid communication with the compressor, A condenser that is in fluid communication with the outlet of the compressor, and which surrounds the plurality of pipes, A support plate is rotatably coupled to the pivot and attached to the first section, A housing and a second section are coupled via at least one mounting section. Equipped with, A device in which, in a first state, the first section is held together by one or more fasteners and the first section is rotatable about the pivot, and in a second state, the first section is disconnected from each other. (Item 36) The apparatus according to item 35, wherein the at least one mounting section is an isolated mounting section. (Item 37) The apparatus described in item 35, wherein the first section includes the water reservoir, the evaporator, and the condenser. (Item 38) The second section is the apparatus described in item 35, which includes the steam chamber and the condenser. (Item 39) The pivot is the apparatus according to item 35, including a biasing member. (Item 40) The apparatus according to item 39, wherein the biasing member is in a relaxed state when the first and second divisions are in the first state, and in a compressed state when the first and second divisions are in the second state. (Item 41) The apparatus according to item 39, wherein the biasing member has a relaxed state and an energy storage state, and the support plate has a displacement path between a first position when the biasing member is in the relaxed state and a second position when the biasing member is in the energy storage state. (Item 42) The device described in item 41, wherein the displacement path is a linear displacement path. (Item 43) The apparatus according to item 41, wherein the displacement path is parallel to the axis of the pivot. (Item 44) The apparatus according to item 39, wherein the biasing member is a gas spring. (Item 45) A steam distillation apparatus, puddle, An evaporator having a first side in communication with the water reservoir and a second side in fluid communication with the steam chamber, A concentrate reservoir, attached to the steam chamber via an inflow path having a first portion and a second portion, wherein the second portion is at least partially defined by an obstruction, the obstruction extending laterally to the first portion within the concentrate reservoir, and dividing the concentrate reservoir into an unshielded section and a shielded section, A float assembly disposed within the shielding section, wherein the float assembly is displaceable over a displacement range including a point at or above the same height as the expected range of the steam chamber liquid level. A sensor is configured to monitor the position of the float assembly and output a data signal indicating the liquid level in the steam chamber based on the position of the float assembly. A compressor having an inlet that establishes fluid communication with the steam chamber and an outlet that establishes fluid communication with the condenser. A device equipped with the following features. (Item 46) The sensor is an encoder, as described in item 45. (Item 47) The float assembly comprises at least one magnet, as described in item 45. (Item 48) The device described in item 47, wherein the sensor is a Hall effect sensor. (Item 49) The apparatus according to item 45, wherein the obstruction extends into the concentrate reservoir at an angle substantially perpendicular to the first portion of the inflow path. (Item 50) The apparatus according to item 45, further comprising a ventilation path extending from the concentrate reservoir to the steam chamber. (Item 51) The apparatus according to item 50, wherein the ventilation path extends parallel to and above the first portion of the inflow path. (Item 52) The apparatus according to item 50, wherein the ventilation path has a smaller cross-sectional area than that of the first portion of the inflow path. (Item 53) The float assembly is attached to the pivot, as described in item 45. (Item 54) The float assembly is displaceable about a pivot on which it is mounted, as described in item 45. (Item 55) A steam distillation apparatus, A water reservoir having a source fluid input, An evaporator having a first side that is in fluid communication with the source fluid input via the water reservoir and a second side that is in fluid communication with the steam chamber, wherein the evaporator is configured to convert the source fluid from the source fluid input into low-pressure steam and concentrate as the source fluid progresses toward the steam chamber, A concentrate reservoir, attached to and positioned laterally thereto to the steam chamber, includes a concentrate level sensor configured to monitor the level of concentrate within the concentrate reservoir and generate a data signal indicating the level of concentrate; A compressor having a low-pressure steam inlet that establishes fluid communication with the steam chamber and a high-pressure steam outlet that establishes fluid communication with the condenser via a condenser inlet, A condenser having a heat transfer relationship with a plurality of external surfaces of the evaporator, wherein the condenser is configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator, and includes a condensation portion and a condensate accumulation portion. An auxiliary condensate reservoir is attached to the condenser, in fluid communication with the condensate storage portion and adjacent to the storage surface of the storage portion, wherein the auxiliary condensate reservoir includes a condensate level sensor configured to monitor the level of condensate in the storage portion and generate a data signal indicating the percentage at which the storage portion is filled with condensate. A device equipped with the following features. (Item 56) The storage portion having a volume of less than 10 liters is the apparatus described in item 55. (Item 57) The apparatus according to item 55, wherein the plurality of external surfaces are the external surfaces of a plurality of evaporator tubes contained within the evaporator. (Item 58) The apparatus according to item 55, wherein the plurality of external surfaces are the external surfaces of 90 to 100 evaporator tubes contained within the evaporator. (Item 59) The apparatus according to item 55, wherein the plurality of external surfaces are the external surfaces of 70 to 80 evaporator tubes contained within the evaporator. (Item 60) The apparatus according to item 55, wherein the condensate level sensor includes a float assembly mounted on a pivot, the float assembly being displaceable about the pivot over a displacement range including a point at the same height as the range of levels defined by the accumulation portion. (Item 61) The apparatus according to item 55, comprising a float assembly, wherein the concentrate level sensor is located within a shielded section of the concentrate reservoir, separated from the unshielded portion of the concentrate reservoir by a barrier. (Item 62) The apparatus according to item 61, wherein the float assembly is mounted on a pivot and is displaceable about the pivot over a displacement range including a point at the same height as or above the expected range of the steam chamber liquid level. (Item 63) The concentrate level sensor is disposed within a sleeve that forms the barrier, as described in item 61. (Item 64) A concentrate level control system for a fluid vapor distillation apparatus, A source fluid input selectively communicates with a source fluid reservoir via at least one input valve, An evaporator having fluid communication with the source input and fluid communication with the steam chamber, wherein the evaporator is configured to convert the source fluid from the source fluid input into a steam flow and a concentrated flow as the source fluid moves toward the steam chamber, An concentrate reservoir, which is attached to the steam chamber via an inflow path and positioned laterally thereto, and which includes an outlet that selectively communicates with the concentrate destination via an outlet valve, A concentrate level sensor is configured to generate a data signal indicating the concentrate level in the steam chamber, A controller is configured to control the operation of at least one inlet valve via a fluid input control loop, analyze the data signal, and carefully modify the concentrate level in a predefined pattern by operating the outlet valve to a closed state when the data signal indicating the concentrate level falls below a first threshold, and operating the outlet valve to an open state when the concentrate level exceeds a second threshold. A system that includes these features. (Item 65) The aforementioned predefined pattern generates a sawtooth waveform when the concentrate levels are plotted over time, as described in item 64 of the system. (Item 66) The system according to item 65, wherein the period of the sawtooth waveform depends at least in part on the fluid input command from the fluid input control loop. (Item 67) The system described in item 66, wherein the fluid input command is determined based on a predefined target concentrate production rate. (Item 68) The controller is configured to operate in multiple operating states, and the predefined target concentrate production rate is state-specific, as described in item 67. (Item 69) The controller is a system according to item 64, which analyzes the data signal on a predefined basis. (Item 70) The system according to item 64, wherein the concentrate level is assigned a predefined expected range, and the first threshold is less than or equal to 50% of the maximum level of the expected range. (Item 71) The system described in item 70, wherein the first threshold is 40% to 50% of the maximum level of the expected range. (Item 72) The system according to item 64, wherein the concentrate level is assigned a predefined expected range, and the second threshold is greater than or equal to 50% of the maximum level of the expected range. (Item 73) The system described in item 72, wherein the second threshold is 50% to 60% of the maximum level of the expected range. (Item 74) The system according to item 64, wherein the concentrate level is assigned a predefined expected range, and the first threshold is less than or equal to 40% of the maximum level of the expected range. (Item 75) The system described in item 74, wherein the first threshold is 40% to 30% of the maximum level of the expected range. (Item 76) The system according to item 64, wherein the concentrate level is assigned a predefined expected range, and the second threshold is greater than or equal to 45% of the maximum level of the expected range. (Item 77) The system described in item 76, wherein the second threshold is 45% to 55% of the maximum level of the expected range. (Item 78) The system according to item 64, wherein the concentrate level is assigned a predefined expected range, the first and second thresholds are defined as percentages of the maximum level within the expected range, and the second threshold is 4 to 20 percent above the first threshold. (Item 79) The destination of the concentrate is a mixing tank, as described in item 64 of the system. (Item 80) A method for controlling the level of concentrate in a distillation device and matching the fluid flow within the distillation device, The source fluid is introduced into the distillation device through at least one inlet valve, As the source fluid moves toward the steam chamber, at least a portion of the source fluid is evaporated, generating steam and concentrates. The concentrate is collected in a concentrate reservoir, which is attached to the steam chamber and positioned laterally thereto, via the aforementioned inflow path. To provide a data signal indicating the concentrate level in the steam chamber from a concentrate level sensor located in the concentrate reservoir, Using a controller, the operation of at least one inlet valve is controlled via a fluid input control loop, and the data signal is analyzed to modify the concentrate level in a predefined pattern by operating the outlet valve of the concentrate reservoir to a closed state when the data signal indicating the concentrate level falls below a first threshold, and to an open state when the concentrate level exceeds a second threshold. Methods that include... (Item 81) The method according to item 80, wherein modifying the concentrate level involves modifying the concentrate level to generate a sawtooth waveform when the concentrate level is plotted over time. (Item 82) The method according to item 80, wherein analyzing the data signal includes analyzing the data signal on a predefined basis. (Item 83) The method according to item 80, further comprising assigning a predefined expected range to the concentrate level and setting the first threshold to be less than or equal to 50% of the maximum level of the expected range. (Item 84) The method according to item 83, wherein setting the first threshold includes setting the threshold to 40% to 50% of the maximum level of the expected range. (Item 85) The method according to item 80, further comprising assigning a predefined expected range of the concentrate levels and setting a second threshold such that it is greater than or equal to 50% of the maximum level of the expected range. (Item 86) The method according to item 85, wherein setting the second threshold includes setting the second threshold to 50% to 60% of the maximum level of the expected range. (Item 87) The method according to item 80, further comprising assigning a predefined expected range to the concentrate level and setting the first threshold to be less than or equal to 40% of the maximum level of the expected range. (Item 88) The method according to item 87, wherein setting the first threshold includes setting the threshold to 40% to 30% of the maximum level of the expected range. (Item 89) The method according to item 80, further comprising assigning a predefined expected range of the concentrate levels and setting a second threshold such that it is greater than or equal to 45% of the maximum level of the expected range. (Item 90) The method according to item 89, wherein setting the second threshold includes setting the second threshold to 45% to 55% of the maximum level of the expected range. (Item 91) The method according to item 80, further comprising assigning a predefined expected range to the concentrate level and setting the first and second thresholds as percentages of the maximum level in the expected range, wherein the second threshold is a 4 to 20 percent point above the first threshold. (Item 92) A temperature control system for controlling the temperature of the product process flow of a distillation device to a required temperature, A source fluid input selectively communicates with a source fluid reservoir via a set of fluid input valves; an evaporator communicating with the source input and a compressor, wherein the evaporator is configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow; A condenser, which is in fluid communication with the compressor, is configured to convert the pressurized steam from the compressor into condensate. A condensate flow path and a concentrate flow path, each including separate first and second heat exchangers, wherein the first and second heat exchangers each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, and the heat exchange portion is located downstream of the source fluid input valve, and comprises the condensate flow path and the concentrate flow path. A condensate temperature sensor configured to generate a data signal indicating the condensate temperature, wherein the condensate temperature sensor is positioned on the condensate flow path downstream of the first heat exchanger, A controller configured to operate a set of input source valves based on a first control loop that controls the total open state time for all input source valves in a set of input source valves, and a second control loop that receives the data signal and the required temperature, divides the total open state time for all the input source valves, and adjusts the condensate temperature to the required temperature. A system equipped with these features. (Item 93) The system according to item 92, wherein the heat exchange portions of the source fluid flow paths within the first and second heat exchangers are arranged countercurrently with respect to their respective condensate and concentrate flow paths. (Item 94) The system further comprises a destination device that communicates fluidly with the condensate flow path via a point-of-use valve, as described in item 92. (Item 95) The required temperature is generated by the destination device in the system described in item 94. (Item 96) The destination device is a medical system, as described in item 94. (Item 97) The medical system described in item 96 is configured to mix at least one dialysate solution. (Item 98) The destination device is a dialysis machine, as described in item 94. (Item 99) The destination device is a hemodialysis machine, as described in item 94. (Item 100) The system according to item 92, wherein at least one of the first and second control loops is a PID control loop. (Item 101) The system described in item 100, wherein the gain of at least one of the terms of the PID control loop is zero. (Item 102) The system described in item 92, wherein the feedforward term is combined with the output of the second control loop. (Item 103) The feedforward term is based on the estimated division of the total open state time, as described in item 102. (Item 104) The system further comprises a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level in the distillation device, and the first control loop is configured to receive a target concentrate level and the current concentrate level data signal as inputs to the first control loop, as described in item 92. (Item 105) The system according to item 92, wherein the controller is further configured to adjust the heater duty cycle based at least in part on the total open state time for all input source valves of a set of input source valves. (Item 106) The system according to item 105, wherein the controller is configured to increase the heater duty cycle when the open state time for all of the input source valves in the set of input source valves is increased. (Item 107) A method for controlling the temperature of the product process flow of a distillation device to a required temperature, By using a controller to operate a set of fluid input valves, the flow of source fluid input to the distillation device is controlled, In the evaporator, at least a portion of the source fluid input is converted into vapor and concentrate, In a condenser, the vapor is condensed into a condensate, Removing at least a portion of the condensate and concentrate from the distillation device through separate condensate and concentrate flow paths, In the first heat exchanger, heat is exchanged between the flow of the source fluid and the condensate flow path, and in the second heat exchanger, heat is exchanged between the flow of the source fluid and the concentrate flow path. A temperature sensor located downstream of the first heat exchanger on the condensate flow path provides the controller with a condensate temperature data signal. A method comprising: using a controller to determine the total open state time for a set of fluid input valves based on a first control loop; and dividing the total open state time between sets of fluid input valves based on a second control loop that receives the temperature data signal and the required temperature. (Item 108) The method according to item 107, further comprising flowing the condensate and concentrate through the condensate and concentrate flow path in a counter-flow direction with respect to the flow of the source fluid. (Item 109) The method according to item 107, further comprising providing the condensate to a destination device by activating a point-of-use valve downstream of the temperature sensor. (Item 110) The required temperature is generated by the destination device, as described in item 109. (Item 111) The aforementioned destination device is a medical system, as described in item 109. (Item 112) The method according to item 107, further comprising mixing the condensate with the dialysate. (Item 113) The aforementioned destination device is a dialysis machine, as described in item 109. (Item 114) The method according to item 109, wherein the destination device is a hemodialysis machine. (Item 115) The method according to item 107, wherein at least one of the first and second control loops is a PID control loop. (Item 116) The method according to item 115, further comprising setting at least one of the gains of the PID control loop to zero. (Item 117) The method described above further includes combining the feedforward term with the output of the second control loop, as described in item 107. (Item 118) The method according to item 117, further comprising determining the feedforward term based on an estimated division of the total open state time. (Item 119) The method according to item 107, further comprising inputting the current concentrate level and target concentrate level provided by a concentrate level sensor into the first control loop. (Item 120) The method according to item 107, further comprising adjusting the heater duty cycle based at least in part on the total open state time for all input source valves of a set of input source valves. (Item 121) The method according to item 120, wherein adjusting the heater duty cycle includes increasing the heater duty cycle when the open state time for all of the input source valves in the set of input source valves is increased. (Item 122) A temperature control system for controlling the temperature of the product process flow of a distillation device to a required temperature, A first source fluid input and a second fluid source input, respectively, selectively communicate with the first and second source fluid reservoirs via a first fluid input valve set and a second fluid input valve set, An evaporator having fluid communication with the first and second source fluid inputs and with the compressor, wherein the evaporator has heating elements for converting the source fluid from the first and second source fluid inputs into a vapor flow and a concentrated flow as the source fluid moves toward the compressor, A condenser, which is in fluid communication with the compressor, is configured to convert the pressurized steam from the compressor into condensate. A condensate flow path and a concentrate flow path, each including separate first and second heat exchangers, wherein the first and second heat exchangers each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, and the heat exchange portion is located at least downstream of the first set of source fluid input valves, A condensate temperature sensor configured to generate a data signal indicating the condensate temperature, wherein the condensate temperature sensor is positioned on the condensate flow path downstream of the first heat exchanger, A controller configured to operate the first set of input source valves based on: a first control loop that controls the total open state time for all input source valves of the first set of input source valves; and a second control loop that receives the data signal and the required temperature, divides the total open state time for all input source valves of the first set of input source valves, and adjusts the condensate temperature to the required temperature, wherein the controller monitors at least one process variable and is configured to operate the second set of input source valves when one of the at least one process variable is outside a predefined threshold; A system that includes these features. (Item 123) The system according to item 122, wherein the first set of fluid input valves includes at least one valve not included in the second set of fluid input valves. (Item 124) The system described in item 122, wherein one of the first and second source fluid inputs is temperature-controlled. (Item 125) The second source fluid input is temperature-controlled, as described in item 122. (Item 126) The system described in item 125, wherein the second source fluid input is a high-temperature fluid input. (Item 127) The system according to item 122, wherein at least one process variable monitored by the controller is the heating element duty cycle. (Item 128) The system described in item 122, wherein at least one process variable monitored by the controller is the output of the first control loop. (Item 129) The system described in item 122, wherein at least one of the process variables is the compressor speed. (Item 130) The system according to item 122, wherein the heat exchange portion of the source fluid flow path is a common flow path for the fluids from the first and second source fluid inputs. (Item 131) The system according to item 122, wherein the heat exchange portion of the source fluid flow path is a flow path for the fluid from the first source fluid input, which is not shared by the fluid from the second source fluid input. (Item 132) A temperature control system for controlling the temperature of the product process flow of a distillation device to a required temperature, A source fluid input selectively communicates with a source fluid reservoir via a set of fluid input valves, and an evaporator selectively communicates with the source fluid input and communicates with a compressor via a bypass valve, wherein the evaporator is configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. A condenser, which is in fluid communication with the compressor, is configured to convert the pressurized steam from the compressor into condensate. A condensate flow path and a concentrate flow path, each including separate first and second heat exchangers, wherein the first and second heat exchangers each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, and the heat exchange portion is located downstream of the source fluid input valve, and comprises the condensate flow path and the concentrate flow path. A condensate temperature sensor configured to generate a data signal indicating the condensate temperature, wherein the condensate temperature sensor is positioned on the condensate flow path downstream of the first heat exchanger, A controller configured to operate a set of input source valves based on a first control loop that controls the total open state time for all input source valves in a set of input source valves, and a second control loop that receives the data signal and the required temperature, divides the total open state time for all the input source valves, and adjusts the condensate temperature to the required temperature. Equipped with, The bypass valve is located in the source fluid flow path downstream of the heat exchange portion of the source fluid flow path, and the bypass valve has a bypass valve state that directs the fluid from the source reservoir to the drain destination, and the controller is configured to activate the bypass valve state when the controller determines that at least one process variable is outside a predetermined threshold. (Item 133) The system according to item 132, wherein the at least one process variable is the relationship between the condensate temperature and the source fluid temperature provided by the source fluid temperature sensor. (Item 134) The system according to item 132, wherein the at least one process variable is the source fluid temperature, which is sensed by a source fluid temperature sensor. (Item 135) The system according to item 132, wherein the at least one process variable is defined at least in part by the condensate temperature and the source fluid temperature sensed by the source fluid temperature sensor. (Item 136) The system according to item 132, wherein the controller is configured to modify the duty cycle of at least one of the input source valves when the bypass valve is in the bypass valve state. (Item 137) The system according to item 132, wherein the controller is configured to increase the duty cycle of at least one of the input source valves when the bypass valve is in the bypass valve state. (Item 138) The system according to item 132, wherein the controller is configured to modify the duty cycle of at least one of the input source valves to 90-100% when the bypass valve is in the bypass valve state. (Item 139) The system according to any one of items 136-138, wherein at least one of the input source valves is a valve that controls the flow of source fluid through the heat exchange portion of the first heat exchanger. (Item 140) A temperature control system for controlling the temperature of the product process flow of a distillation system to a required temperature, A source fluid input selectively communicates with a source fluid reservoir via a set of fluid input valves, and a distillation device configured to generate concentrated and condensed fluids. A condensate flow path and a concentrate flow path, each including separate first and second heat exchangers, wherein the first and second heat exchangers each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, and the heat exchange portion is located downstream of the source fluid input valve, and comprises the condensate flow path and the concentrate flow path. A condensate temperature sensor configured to generate a data signal indicating the condensate temperature, wherein the condensate temperature sensor is positioned on the condensate flow path downstream of the first heat exchanger, A point-of-use device that selectively communicates with the condensate flow path, the point-of-use device having an outlet channel for an output fluid generated by the point-of-use device, the output channel having a third heat exchanger including a heat exchange portion of the branch of the source fluid flow path, A controller configured to actuate a set of input source valves based on a first control loop and a second control loop that control the flow of source fluid through the heat exchange portions of the first and second heat exchangers, and based on at least one process variable, wherein the controller acts a branch valve to branch the source fluid flow path when the at least one process variable is outside a predetermined threshold, and A system equipped with these features. (Item 141) The system according to item 140, wherein the at least one process variable is the relationship between the condensate temperature and the source fluid temperature provided by the source fluid temperature sensor. (Item 142) The system according to item 140, wherein the at least one process variable is the source fluid temperature, which is sensed by a source fluid temperature sensor. (Item 143) The system according to item 140, wherein the at least one process variable is defined at least in part by the source fluid temperature sensed by the condensate temperature and source fluid temperature sensors. (Item 144) The aforementioned point-of-use device is a medical device, as described in item 140. (Item 145) The aforementioned point-of-use device is a dialysis machine, as described in item 140. (Item 146) The aforementioned point-of-use device is a hemodialysis machine or a peritoneal dialysis machine, as described in item 140. (Item 147) The system according to item 140, wherein the branch of the source fluid flow path is located upstream of the heat exchange portion of the source fluid flow path in the first and second heat exchangers. (Item 148) The output fluid is dialysate wastewater, as described in item 140. (Item 149) A condensate accumulation rate control system for controlling the rate of condensate accumulation in a distillation device, A source fluid input selectively communicates with a source fluid reservoir via a set of fluid input valves; and an evaporator fluid-communicates with a compressor having an impeller fluid-communicating with the source input and operably coupled to an impeller motor, wherein the evaporator is configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor. A condenser having a heat transfer relationship with a plurality of external surfaces of the evaporator, wherein the condenser is configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator. A condensate level sensor is configured to sense the current level of condensate in the condenser, At least one controller configured to control the rotational speed of an impeller by periodically generating an impeller motor command based on the last motor speed command, a motor speed target, and a speed command increment limit, wherein the motor speed target is calculated by a control loop that receives the current condensate level and a desired condensate level as control loop inputs, and A system that includes these features. (Item 150) The speed command increment limit is ≤10 rpm / sec, as described in item 149 for the system. (Item 151) The speed command increment limit is ≤5 rpm / sec, as described in item 149 for the system. (Item 152) The system according to item 149, wherein the controller is configured to compare the impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and adjust the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold when the impeller motor command is below the minimum command speed threshold, and equal to the maximum command speed threshold when the impeller motor command is above the maximum command speed threshold. (Item 153) The minimum command speed threshold is 1,500 to 2,500 rpm, as described in item 152. (Item 154) The minimum command speed threshold is 2,000 rpm, as described in item 152. (Item 155) The maximum command speed threshold is calculated each time the motor speed command is generated, according to the system described in item 152. (Item 156) The maximum command speed threshold is calculated based on at least one motor parameter, as described in item 155. (Item 157) The system further comprises a motor temperature sensor configured to output a temperature data signal indicating the temperature of the impeller motor, and a power factor correction current monitoring circuit configured to output a PFC data signal indicating the current power factor correction current, wherein the maximum command speed threshold is calculated based on the temperature data signal and the PFC data signal, as described in item 155. (Item 158) The maximum command speed is set with a predetermined value as the upper limit, as described in item 155 of the system. (Item 159) The predetermined value is 4,500 to 6,500 rpm, as described in item 158. (Item 160) The predetermined value is 5,000 rpm, as described in item 158. (Item 161) The predetermined value is 2.5 times greater than the minimum command speed threshold, as described in item 158. (Item 162) A method for controlling the rate of condensate accumulation in a distillation apparatus, Providing the source fluid input to the distillation device, In the evaporator, at least a portion of the source fluid input is evaporated into low-pressure steam, Compressing the low-pressure steam into high-pressure steam via an impeller, In the condenser, the high-pressure steam is condensed into a condensate, and heat is transferred from the high-pressure steam to the evaporator. The level of condensate in the condenser, as sensed by the condensate level sensor, is provided to the controller. Using the controller, the motor speed target is calculated based on the condensation level and the desired condensation level. The rotational speed of the impeller is controlled by periodically generating impeller motor commands based on the last motor speed command, motor speed target, and speed command increment limit using a controller. Methods that include... (Item 163) The speed command increment limit is ≤10 rpm / sec, as described in item 162. (Item 164) The speed command increment limit is ≤5 rpm / sec, as described in item 162. (Item 165) The method according to item 162, further comprising using a controller to compare the impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and adjusting the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold when the impeller motor command is below the minimum command speed threshold, and equal to the maximum command speed threshold when the impeller motor command is above the maximum command speed threshold. (Item 166) The method according to item 165, wherein the minimum command speed threshold is 1,500 to 2,500 rpm. (Item 167) The method according to item 165, wherein the minimum command speed threshold is 2,000 rpm. (Item 168) The method according to item 165, further comprising calculating the maximum command speed threshold each time the motor speed command is generated. (Item 169) Calculating the maximum command speed threshold according to item 168 includes calculating the maximum command speed threshold based on at least one motor parameter. (Item 170) The method according to item 168 further includes providing a temperature data signal indicating the temperature of the motor from a motor temperature sensor to the controller and providing a power factor correction data signal indicating the current power factor correction current from a monitoring circuit to the controller. (Item 171) The method according to item 170 further includes calculating the maximum command speed threshold based on the temperature data signal and the power factor correction data signal. (Item 172) The method according to item 168 further includes setting a predetermined value as the upper limit for the maximum command speed threshold. (Item 173) The method according to item 172, wherein the predetermined value is 4,500 to 6,500 rpm. (Item 174) The method according to item 172, wherein the predetermined value is 5,000 rpm. (Item 175) The method according to item 172, wherein the predetermined value is 2.5 times greater than the minimum command speed threshold. (Item 176) A distillation device, A source fluid input selectively fluid-communicates with a source fluid reservoir via a set of fluid input valves; an evaporator fluid-communicates with the source input and with a compressor, wherein the evaporator is configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor; A condenser, which is in fluid communication with the compressor, is configured to convert the pressurized steam from the compressor into condensate. A condensate flow path and a concentrate flow path, each including separate first and second heat exchangers, wherein the first and second heat exchangers each include a heat exchange portion of the source fluid flow path from the source fluid reservoir, and the heat exchange portion is located downstream of the source fluid input valve, and comprises the condensate flow path and the concentrate flow path. A condensate temperature sensor configured to generate a data signal indicating the condensate temperature, wherein the condensate temperature sensor is positioned on the condensate flow path downstream of the first heat exchanger, A controller configured to operate a set of input source valves based on: a first multimodal control loop that generates a certain number of provisional total open state commands for all input source valves of a set of input source valves; a slider that generates a single total open state command from the number of provisional commands; and a second control loop that receives the data signal and temperature setpoint, distributes the total open state command among all the input source valves, and adjusts the condensate temperature to the temperature setpoint. A device equipped with the following features. (Item 177) The device according to item 176, wherein the heat exchange portions of the source fluid flow paths within the first and second heat exchangers are arranged countercurrently with respect to their respective condensate and concentrate flow paths. (Item 178) The controller is configured to operate in multiple operating states, and the temperature setpoint depends on the state, as described in item 176. (Item 179) The device according to item 176, further comprising a destination device that is in fluid communication with the condensate flow path via a point-of-use valve. (Item 180) The destination device is a medical system, as described in item 179. (Item 181) The medical system is configured to mix at least one dialysate solution, as described in item 180. (Item 182) The destination device is a dialysis machine, as described in item 179. (Item 183) The destination device is a hemodialysis machine, as described in item 179. (Item 184) The device according to item 176, wherein at least one of the first multimodal control loop and the second control loop includes a PID control loop. (Item 185) The device described in item 184, wherein the gain of at least one of the terms in the PID control loop is zero. (Item 186) The number of the aforementioned provisional total open state commands is controlled by the output of at least one regulator control loop, as described in item 176. (Item 187) The distillation device further comprises a reservoir between the source input and the evaporator, and one of the at least one regulator control loops is configured to produce an output based on a target reservoir temperature and the current reservoir temperature measured by a reservoir temperature sensor, which is configured to generate a data signal representing the temperature of the fluid in the reservoir, as described in item 186. (Item 188) The device according to item 186, wherein one of the at least one controller control loops is configured to produce an output based on a target steam temperature and the current steam temperature measured by a steam temperature sensor, which is configured to generate a data signal representing the temperature of the steam flow. (Item 189) The device according to item 176, further comprising a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level in the distillation device, the controller configured to determine the current blowdown rate from the concentrate level data signal, and the first multimodal control loop configured to receive the target blowdown rate and the current blowdown rate data signal as inputs. (Item 190) The device further comprises an evaporator level sensor configured to output an evaporator data signal, and the controller is configured at least partially to generate at least one of the provisional total open state commands based on the input of a target evaporator sensor level and the evaporator data signal, as described in item 176. (Item 191) The target evaporator sensor level and the evaporator data signal are input to the differential controller, as described in item 190. (Item 192) The device according to item 191, wherein the differential controller is a PID controller, and the PID controller has a D-term gain that is at least one order of magnitude higher than the P and I terms. (Item 193) The device according to item 176, wherein at least one of the provisional total open state commands is a first production temperature state command, and at least one of the provisional total open state commands is a second production temperature state command. (Item 194) A steam distillation apparatus, A water reservoir having a source fluid input, An evaporator having a first side in fluid communication with the source fluid input via the water reservoir and a second side in fluid communication with a steam chamber, wherein the evaporator is configured to convert the source fluid from the source fluid input into low-pressure steam and concentrate, and a non-uniform liquid level exists within the evaporator during operation, An evaporator reservoir that is disposed laterally with respect to the evaporator and is in fluid communication with it via the water sump, the evaporator reservoir including a level sensor configured to monitor the level of the water column in the evaporator reservoir and generate a data signal indicative of the level of the water column. A compressor having a high-pressure steam outlet that establishes fluid communication with a condenser via a low-pressure steam inlet and a condenser inlet that establish fluid communication with the vapor chamber. A condenser in heat transfer relation with a plurality of external surfaces of the evaporator, the condenser configured to condense a high-pressure steam flow from the compressor by bringing the high-pressure steam flow into contact with the plurality of external surfaces of the evaporator, the condenser including a condensation portion and a condensate accumulation portion. A processor configured to actuate a set of input source valves to the source fluid input, at least in part based on the data signal. An apparatus comprising. (Item 195) The apparatus according to item 194, wherein the level sensor includes a displaceable member that is displaceable over a displacement range that is less than the height of the evaporator reservoir. (Item 196) The apparatus according to item 194, wherein the level sensor includes a displaceable member that is displaceable over a displacement range that extends from a first end portion of the evaporator reservoir to at least a midpoint of the evaporator reservoir, the displacement range being a distance less than 70% of the height of the evaporator reservoir. (Item 197) The apparatus according to item 196, wherein the first end is the end of the evaporator reservoir that is furthest from the water sump. (Item 198) The apparatus according to item 194, wherein the evaporator reservoir communicates with the vapor chamber via a ventilation path that extends from a first end portion of the evaporator reservoir. (Item 199) The apparatus according to item 198, wherein the ventilation path extends from the evaporator reservoir to a condensate reservoir that is attached to and disposed laterally with respect to the vapor chamber. (Item 200) The apparatus according to item 194, wherein the height of the evaporator reservoir exceeds the height of the evaporator. (Item 201) The apparatus according to item 194, wherein the processor is configured in part to determine the total open state time for a set of input source valves based on the target water column level and the current water column level determined through analysis of the data signals. (Item 202) The apparatus according to item 201, wherein the processor is configured to determine the total open state time for a set of input source valves based on the output of a PID controller which receives the target water column level and the current water column level as inputs. (Item 203) The apparatus according to item 202, wherein the gain for at least one of the P, I, and D terms of the PID controller is zero. (Item 204) The apparatus according to item 202, wherein the gain for the D term of the PID controller is at least one order of magnitude greater than the gains for the P and I terms of the PID controller. (Item 205) The apparatus according to item 202, wherein the gain for the D term of the PID controller is more than two orders of magnitude greater than the gains for the P and I terms of the PID controller. (Item 206) The apparatus according to item 201, wherein the processor is configured in part to determine the total open state time based on a target blowdown rate and the current blowdown rate, such as indicated by a blowdown level data signal produced by a blowdown level sensor in a blowdown reservoir attached to the steam chamber. (Item 207) The apparatus according to item 194, wherein the processor is configured in part to determine a total open state command based on the output of at least one regulator control loop. (Item 208) The apparatus according to item 207, wherein one of the at least one controller control loops is configured to produce an output based on a target reservoir temperature and the current reservoir temperature measured by a reservoir temperature sensor, which is configured to generate a data signal representing the temperature of the fluid in the reservoir. (Item 209) The apparatus according to item 207, wherein one of the at least one controller control loops is configured to produce an output based on a target steam temperature and the current steam temperature measured by a steam temperature sensor configured to generate a data signal representing the temperature of the steam flow. (Item 210) The apparatus according to item 194, wherein the controller is configured to modify the total open state command for a set of input source valves in response to a change in the water column level indicated by the data signal. (Item 211) The apparatus according to item 194, wherein the controller is configured to modify the total open state commands for a set of input source valves in proportion to the rate of change of the water column as indicated by the data signal. (Item 212) A method for controlling the flow of a source fluid into a distillation device, To establish a non-uniform liquid level within the evaporator of the distillation device, Using a first level sensor, the liquid column level in the evaporator reservoir, which is in fluid communication with the evaporator and positioned at the same height as the evaporator, is detected. A second level sensor is used to sense the concentrate level in the concentrate reservoir, which is in fluid communication with the evaporator. Using a processor, generate a source inlet valve opening time command, at least partially, based on the concentrate level, the target concentrate accumulation rate, and the delta between the liquid column level and the target liquid column level. To command a certain number of source inlet valves to open based on the source inlet valve opening time command. Methods that include... (Item 213) The method according to item 212, wherein sensing the liquid column level involves displacing a displaceable member over a displacement range less than the height of the evaporator reservoir. (Item 214) The method according to item 212, wherein sensing the liquid column level involves displacing a displaceable member over a displacement range extending from a first end portion of the evaporator reservoir to at least the midpoint of the evaporator reservoir, the displacement range being a distance of less than 70% of the height of the evaporator reservoir. (Item 215) The method according to item 214, wherein the first end is the furthest distal end of the evaporator reservoir of the water reservoir of the distillation device. (Item 216) The method according to item 212, further comprising venting air from the evaporator reservoir through a vent path into the vapor chamber of the distillation device located above the evaporator. (Item 217) The ventilation path extends from the evaporator reservoir to a concentrate reservoir attached to and positioned laterally thereto in the steam chamber, according to the method of item 216. (Item 218) The method according to item 212, wherein generating the source inlet valve open time command includes inputting the delta to the PID controller. (Item 219) The apparatus according to item 218, wherein the gain with respect to at least one of the P, I, and D terms of the PID controller is zero. (Item 220) The apparatus according to item 218, wherein the gain for the D term of the PID controller is at least one order of magnitude greater than the gains for the P and I terms of the PID controller. (Item 221) The apparatus according to item 218, wherein the gain for the D term of the PID controller is more than two orders of magnitude greater than the gains for the P and I terms of the PID controller. (Item 222) The apparatus according to item 212, wherein generating the source inlet valve opening time command includes determining the current concentrate accumulation rate from the concentrate level and calculating the delta between the target concentrate rate and the current concentrate accumulation rate. (Item 223) The apparatus according to item 212, wherein generating the source inlet valve open time command includes generating the output of at least one regulator control loop. (Item 224) The apparatus according to item 223, further comprising sensing the current reservoir temperature using a reservoir temperature sensor, and generating an output of at least one regulator control loop, which includes producing the output based on a target reservoir temperature and the current reservoir temperature. (Item 225) The apparatus according to item 223, further comprising using a vapor temperature sensor to sense the temperature of the vapor flow in the distillation device, and generating an output of at least one regulator controller, which produces the output based on a target vapor temperature and the current vapor temperature. (Item 226) The apparatus according to item 212, further comprising modifying the source inlet valve opening time command in response to a change in the liquid column level. (Item 227) The apparatus according to item 212, further comprising modifying the source inlet valve opening time command in proportion to the rate of change of the liquid column level. (Item 228) A fluid vapor distillation apparatus, At least one controller, A source inlet and a fluid source selectively communicate with each other via at least one valve, An evaporator that is in fluid communication with the aforementioned source inlet, A steam chamber coupled to the evaporator and in fluid communication with the compressor, wherein the outer surface of the steam chamber forms part of the inlet flow path to the compressor and part of the outlet flow path to the compressor outlet, A concentrate reservoir, the concentrate reservoir being attached to the steam chamber via an inflow path and positioned laterally to the steam chamber, such that at least a portion of the concentrate reservoir is at the same height as the steam chamber; A condenser that is in fluid communication with the outlet of the compressor via a linear flow path, the linear flow path having a first surface defining a portion of the steam chamber and an opposing surface defining a portion of the condenser, and the condenser is fixedly mounted to a sheet and includes a condenser inlet. At least a portion of the product process flow reservoir is at the same height as the condenser, and the product process flow reservoir is connected to the condenser by the product reservoir inlet and positioned laterally to the condenser. A device equipped with the following features. (Item 229) The aforementioned inflow path includes obstacles, as described in item 228. (Item 230) The apparatus according to item 229, wherein the obstruction includes a wall that extends into the concentrate reservoir at an angle substantially perpendicular to the inflow path. (Item 231) The apparatus according to item 229, wherein the obstruction extends into the concentrate reservoir, dividing the concentrate reservoir into a first portion and a second shielding portion. (Item 232) The aforementioned obstruction is the apparatus according to item 228, which includes at least one ventilation port. (Item 233) The apparatus described in item 228, wherein the product reservoir inlet is adjacent to the product accumulation surface of the condenser. (Item 234) The apparatus according to item 228, wherein the compressor is driven by a motor and is located in a receiving well that is partially fitted into the side of the steam chamber. (Item 235) The apparatus according to item 228, wherein the compressor includes an impeller that extends laterally with respect to the steam chamber and rotates about an axis parallel to the longitudinal axis of the steam chamber. (Item 236) A distillation device, A set of fluid input valves selectively communicates the source with the source fluid input, An evaporator, which is in fluid communication with a compressor, having an impeller that is in fluid communication with the source input and operably coupled to an impeller motor, wherein the evaporator is configured to convert the source fluid from the source fluid input into a vapor flow and a concentrated flow as the source fluid moves toward the compressor, A condenser having a heat transfer relationship with a plurality of external surfaces of the evaporator, wherein the condenser is configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator. A concentrate level sensor is positioned above the evaporator, has an inflow path, extends parallel to the evaporator, has a long axis, and is configured to sense the current level of concentrate in the concentrate reservoir. At least one controller configured to control the rotational speed of the impeller in the low-temperature distillate production state and the high-temperature distillate production state by periodically generating an impeller motor command based on the nominal low-temperature distillate production speed command in the low-temperature distillate production state and the nominal high-temperature distillate production speed command in the high-temperature distillate production state, wherein the nominal low-temperature distillate production speed command is a motor speed command that is faster than the nominal high-temperature distillate production speed command. A distillation apparatus equipped with the following features. (Item 237) The distillation apparatus according to item 236, wherein adjustment is made to the impeller motor command based on a data signal from the concentrate level sensor indicating the level of concentrate in the concentrate reservoir. (Item 238) The adjustment is limited by the impeller motor command increment limit, as described in item 237 of the distillation apparatus. (Item 239) The impeller motor command increment limit is ≤10 rpm / sec, as described in item 238 for the distillation device. (Item 240) The impeller motor command increment limit is ≤5 rpm / sec, as described in item 238 for the distillation device. (Item 241) The distillation apparatus according to item 237, wherein the impeller motor command is decremented when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds a first threshold. (Item 242) The distillation apparatus according to item 241, wherein the first threshold is defined as the concentrate level when the concentrate reservoir is at a predefined fill value of 65-80%. (Item 243) The distillation apparatus according to item 237, wherein the impeller motor command is held at or below a previously commanded impeller motor command value when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds a first threshold. (Item 244) The distillation apparatus according to item 243, wherein the first threshold is defined as the concentrate level when the concentrate reservoir is at a predefined fill value of 65-80%. (Item 245) The distillation apparatus according to item 237, wherein the impeller motor command is incremented when the data signal indicates that the level of concentrate in the concentrate reservoir exceeds a second threshold. (Item 246) The aforementioned high-temperature distillate production nominal rate command is a calibration value defined during production, as described in item 236 for the distillation device. (Item 247) The distillation apparatus according to item 236, wherein the nominal rate command for high-temperature distillate production is less than 80% of the nominal rate command for low-temperature distillate production. (Item 248) The distillation apparatus described in item 236, wherein the nominal rate command for high-temperature distillate production is greater than 45% of the nominal rate command for low-temperature distillate production. (Item 249) The nominal low-temperature distillate production speed command is 4,500 rpm for the distillation apparatus described in item 236. (Item 250) The nominal speed command for low-temperature distillate production is 5,000 rpm, according to the distillation apparatus described in item 236. (Item 251) A method for controlling the compressor of a distillation device, Opening at least one fluid input valve to deliver source fluid from the fluid source into the water reservoir of the distillation device, In the evaporator, the source fluid is converted into concentrated logistics and vapor flow, The process involves using a processor to determine a state-specific compressor speed command, wherein the compressor speed command is based on the nominal low-temperature distillate production speed command in the low-temperature distillate production state and the nominal high-temperature distillate production speed command in the high-temperature distillate production state, and the nominal low-temperature distillate production speed command is a motor speed command that is faster than the nominal high-temperature distillate production speed command. Using the aforementioned processor, the final command speed is generated based on the compressor speed command. Using the aforementioned processor, the rotation of the compressor impeller is commanded at the final command speed. Compressing the steam flow via the compressor, As the vapor flow condenses, the vapor flow condenses into a condensate, and heat is transferred to the evaporator. Methods that include... (Item 252) The method according to item 251, further comprising using a level sensor to sense the level of concentrate in a concentrate reservoir that is in fluid communication with the evaporator. (Item 253) The method according to item 252, wherein generating the final command speed includes determining an adjustment to the compressor speed command based on the level of the concentrate. (Item 254) The method according to item 253, wherein determining the adjustment includes decrementing the compressor speed command when the concentrate level exceeds a first threshold. (Item 255) The method according to item 254, wherein the first threshold is defined as the concentrate level when the concentrate reservoir is at a predefined fill value of 65-80%. (Item 256) The method according to item 253, wherein determining the adjustment includes keeping the final command rate at or below a previously commanded final command rate when the concentrate level exceeds a first threshold. (Item 257) The method according to item 253, wherein determining the adjustment includes decrementing the compressor speed command when the concentrate level exceeds a second threshold. (Item 258) The method according to item 251, wherein generating the final command speed includes determining an adjustment to the compressor speed command. (Item 259) The adjustment is limited by an increment limit, as described in item 258. (Item 260) The method described in item 258, wherein the increment limit is ≤10 rpm / sec. (Item 261) The increment limit is ≤5 rpm / sec, as described in item 258. (Item 262) The nominal rate command for high-temperature distillate production is a calibration value defined during production, as described in item 251. (Item 263) The method according to item 251, wherein the nominal rate command for high-temperature distillate production is less than 80% of the nominal rate command for low-temperature distillate production. (Item 264) The method described in item 251, wherein the nominal rate command for high-temperature distillate production is greater than 45% of the nominal rate command for low-temperature distillate production. (Item 265) The nominal speed command for the aforementioned low-temperature distillate production is 4,500 rpm, as described in item 251. (Item 266) The nominal speed command for the aforementioned low-temperature distillate production is 5,000 rpm, as described in item 251. (Item 267) A distillation device, A water reservoir and a source are selectively connected via a set of fluid input valves. The water reservoir comprises at least one heating element and at least one water reservoir temperature sensor, wherein the water reservoir temperature sensor is configured to generate a water reservoir temperature data signal. An evaporator having a first side in fluid communication with the water reservoir and a second side in fluid communication with a compressor having an impeller operably coupled to an impeller motor, wherein the evaporator is configured to convert a source fluid from the source fluid input into a vapor flow and a concentrate, A condenser having a heat transfer relationship with a plurality of external surfaces of the evaporator, wherein the condenser is configured to condense the high-pressure vapor flow from the compressor by bringing the high-pressure vapor flow into contact with the plurality of external surfaces of the evaporator. A concentrate level sensor is positioned above the evaporator, has an inflow path, extends parallel to the evaporator, has a long axis, and is configured to sense the current level of concentrate in the concentrate reservoir. A steam temperature sensor is placed within the flow path of the steam flow and configured to generate a steam temperature data signal. At least one controller configured to determine a duty cycle command relating to at least one heating element, wherein the duty cycle command is at least partially based on a total source open command relating to the target temperature of the steam flow, the steam temperature data signal, the reservoir temperature data signal, and a set of fluid input valves. A distillation apparatus equipped with the following features. (Item 268) The distillation apparatus according to item 267, wherein the target temperature of the vapor stream is 108°C. (Item 269) The distillation apparatus according to item 267, wherein the controller is configured to adjust the duty cycle command to match at least one limit. (Item 270) The aforementioned limit is the maximum power consumption limit, as described in item 269 for the distillation device. (Item 271...

Claims

1. A steam distillation system for providing a distillate at a controlled temperature, wherein the steam distillation system is A steam distillation apparatus is provided, which is configured to receive source water from a fluid source and produce a distillate. The device described above, A compressor that receives source steam and produces compressed steam, wherein the compressor is supported on a bearing that is lubricated using the condensed compressed steam, A purifier, wherein the purifier is An evaporator that receives source water, the evaporator converts the source water into source water vapor and concentrate, A steam chamber fluidly connected to the evaporator and the compressor, A condenser fluidly connected to the compressor, wherein the condenser converts compressed vapor into a distillate, and A purifier equipped with, A concentrate reservoir and a concentrate level sensor, A source fluid path extending from the fluid source and branching to at least a first branching source path and a second branching source path, A concentrate flow path, which is fluidly connected to the steam chamber and has concentrate output, A distillate flow path, which is fluidly connected to the condenser and has a distillate output, A first heat exchanger comprising at least one source constant ratio valve on one of the first and second branching source paths, and at least a portion of the distillate flow path, A second heat exchanger comprising at least a portion of the concentrate flow path and a portion of the second branching source path, A distillate sensor assembly communicating with the distillate flow path and located downstream of the first heat exchanger, wherein the distillate sensor assembly is configured to generate a distillate temperature measurement value, A control system for controlling the steam distillation system, wherein the control system is A concentrate controller programmed to control the concentrate valve, A source flow controller programmed to control the source flow valve, A concentrate level sensor that communicates with the concentrate controller and the source flow controller. Equipped with, The concentrate level sensor transmits a signal related to the concentrate level, indicating the concentrate level, to the concentrate controller and the source flow controller. The source fluid controller is programmed to activate the source fluid valve based at least on the concentrate level sensor signal, The concentrate controller is programmed to activate the concentrate valve based at least on the concentrate level sensor signal, The concentrate level is maintained using the concentrate level sensor signal as input to the control system, A controller configured to control the at least one source-fixed valve and Equipped with, The aforementioned controller, Based on the concentrate accumulation rate and target concentrate accumulation rate calculated from the level measurement output of the concentrate level sensor, the total source constant ratio valve duty cycle is determined. Based on the aforementioned total source constant ratio valve duty cycle, the volume of source water received by the steam distillation device is controlled, Receiving the aforementioned distillate temperature measurement, To determine the difference between the first target temperature and the measured distillate temperature, In the first operating mode, the at least one source constant ratio valve is used to separate the source water from the fluid source between the first heat exchanger and the second heat exchanger based on the difference between the first target temperature and the measured distillate temperature. A system configured to perform the following actions.

2. The steam distillation apparatus is The evaporator reservoir is in fluid communication with the evaporator, An evaporator level sensor is placed inside the evaporator reservoir. Furthermore, The evaporator level sensor communicates with the controller and transmits a data signal to the controller that provides the level of the water column in the evaporator reservoir. The system according to claim 1, wherein in a second mode, the controller is configured to determine the total source constant ratio valve duty cycle based at least in part on the evaporator level data signal indicating the level of the water column in the evaporator reservoir.

3. The system according to claim 1, wherein the first target temperature is at least 20°C but 25°C or less.

4. The system according to claim 1, further comprising a source fluid temperature sensor that communicates with the controller, the source fluid temperature sensor providing the controller with data relating to the source fluid temperature measurement, and the controller being configured to determine the first target temperature, at least in part, based on the source fluid temperature measurement received from the source fluid temperature sensor.

5. The system according to claim 1, further comprising a concentrate sensor assembly configured to communicate with the concentrate flow path downstream of a portion of the concentrate flow path contained in the second heat exchanger and to generate concentrate temperature measurements.

6. The system according to claim 5, wherein the controller is configured, at least in part, to open at least one source control valve that controls the source water to the second heat exchanger based on the difference between a third target temperature and the concentrated temperature measurement.

7. The system according to claim 6, wherein the third target temperature is the historical average of the concentrate temperature.

8. The system according to claim 1, wherein the controller is configured to open at least one source control valve that controls the source water to the second heat exchanger, at least partially based on a minimum limit.

9. The system according to claim 8, wherein the minimum limit is the larger of a predefined percentage of the combined duty cycles for all of the source-fixed ratio valves or a predefined duty cycle.

10. The system according to claim 1, wherein the controller is located in an electronic equipment box and is in a heat transfer relationship with the flow path from the source water that leads to the second heat exchange.

11. The system according to claim 10, wherein the controller is configured to determine an electronic equipment box cooling duty cycle command and to open at least one source control valve that controls the source water to the second heat exchanger, at least partially based on the electronic equipment box cooling duty cycle command.

12. The system according to claim 1, wherein the distillate sensor assembly comprises a redundant temperature sensor.

13. The system according to claim 1, wherein the distillate sensor assembly comprises a redundant temperature sensor and a redundant conductivity sensor.

14. The system according to claim 1, wherein the first and second heat exchangers are helical and are formed by winding the heat exchangers around the outside of the distillation device.

15. A steam distillation system for providing a distillate at a controlled temperature, wherein the steam distillation system is A steam distillation apparatus is provided, which is configured to receive source water from a fluid source and produce a distillate. The device described above, A compressor that receives source steam and produces compressed steam, wherein the compressor is supported on a bearing that is lubricated using the condensed compressed steam, A purifier, wherein the purifier is An evaporator that receives source water, the evaporator converts the source water into source water vapor and concentrate, A steam chamber fluidly connected to the evaporator and the compressor, A condenser fluidly connected to the compressor, wherein the condenser converts compressed vapor into a distillate, and A purifier equipped with, A concentrate reservoir and a concentrate level sensor, A source fluid path extending from the fluid source and branching to at least a first branching source path and a second branching source path, A concentrate flow path, which is fluidly connected to the steam chamber and has concentrate output, A distillate flow path, which is fluidly connected to the condenser and has a distillate output, A first heat exchanger comprising at least one source constant ratio valve on one of the first and second branching source paths, and at least a portion of the distillate flow path, A second heat exchanger comprising at least a portion of the concentrate flow path and a portion of the second branching source path, A distillate sensor assembly communicating with the distillate flow path and located downstream of the first heat exchanger, wherein the distillate sensor assembly is configured to generate a distillate temperature measurement value, A control system for controlling the steam distillation system, wherein the control system is A concentrate controller programmed to control the concentrate valve, A source flow controller programmed to control the source flow valve, A concentrate level sensor that communicates with the concentrate controller and the source flow controller. Equipped with, The concentrate level sensor transmits a signal related to the concentrate level, indicating the concentrate level, to the concentrate controller and the source flow controller. The source fluid controller is programmed to activate the source fluid valve based at least on the concentrate level sensor signal, The concentrate controller is programmed to activate the concentrate valve based at least on the concentrate level sensor signal, The concentrate level is maintained using the concentrate level sensor signal as input to the control system, A controller configured to control the at least one source-fixed valve and Equipped with, The aforementioned controller, Based on the concentrate accumulation rate and target concentrate accumulation rate calculated from the level measurement output of the concentrate level sensor, the total source constant ratio valve duty cycle is determined. Based on the aforementioned total source constant ratio valve duty cycle, the volume of source water received by the steam distillation device is controlled, Receiving the aforementioned distillate temperature measurement, To determine the difference between the first target temperature and the measured distillate temperature, In the first operating mode, the source water is separated from the fluid between the first heat exchanger and the second heat exchanger based on the difference between the first target temperature and the measured distillate temperature, using the at least one source ratio valve. In the second operating mode, by controlling the at least one source control valve, the entire total source control valve duty cycle is allocated to the at least one source control valve that controls the flow of source water to the second heat exchanger, and the at least one source control valve that controls the flow of source water to the first heat exchanger is released for an additional duty cycle below a predetermined limit. A system configured to perform the following actions.

16. The system according to claim 15, wherein the predefined limit is selected from a list consisting of 5%, 2%, less than 2%, and zero.

17. The system according to claim 15, wherein the first operating mode is a low-temperature distillate production state, and the second operating mode is a high-temperature distillate production state.

18. The system according to claim 15, wherein the controller is configured to open at least one source control valve that controls the source water to the first heat exchanger based on a second target temperature and the difference between the second target temperature and the concentrate temperature in the second operating state.

19. The system according to claim 18, wherein the second target temperature is at least 65°C higher than the first target temperature.

20. The system according to claim 18, wherein the second target temperature is at least 50°C higher than the first target temperature.

21. The system according to claim 18, wherein the second target temperature is greater than 95°C and less than 100°C.

22. The system according to claim 18, wherein the second target temperature is 96°C.

23. A method for a steam distillation system that provides a distillate at a controlled temperature, the method comprising a steam distillation device configured to receive a certain volume of source water from a fluid source and produce a distillate, the device being A compressor that receives source steam and produces compressed steam, wherein the compressor is supported on a bearing that is lubricated using the condensed compressed steam, A purifier, wherein the purifier is An evaporator that receives source water, the evaporator converts the source water into source water vapor and concentrate, A steam chamber fluidly connected to the evaporator and the compressor, A condenser fluidly connected to the compressor, wherein the condenser converts compressed vapor into a distillate, and A purifier equipped with, A concentrate reservoir and a concentrate level sensor, A source fluid path extending from the fluid source and branching into a first branching source path and a second branching source path, A concentrate flow path, which is fluidly connected to the steam chamber and has concentrate output, A distillate flow path, which is fluidly connected to the condenser and has a distillate output, The first source determinant valve is one level above the first and second branching source paths, A first heat exchanger comprising at least a portion of the distillate flow path and a portion of the first branching source path, A second heat exchanger comprising at least a portion of the concentrate flow path and a portion of the second branching source path, A distillate sensor assembly, which is in communication with the distillate flow path and located downstream of the first heat exchanger, is configured to generate a distillate temperature measurement value. A control system for controlling the steam distillation system, wherein the control system is A concentrate controller programmed to control the concentrate valve, A source flow controller programmed to control the source flow valve, A concentrate level sensor that communicates with the concentrate controller and the source flow controller. Equipped with, The concentrate level sensor transmits a signal related to the concentrate level, indicating the concentrate level, to the concentrate controller and the source flow controller. The source fluid controller is programmed to activate the source fluid valve based at least on the concentrate level sensor signal, The concentrate controller is programmed to activate the concentrate valve based at least on the concentrate level sensor signal, The concentrate level is maintained using the concentrate level sensor signal as input to the control system. To be equipped with, Based on the concentrate accumulation rate and target concentrate accumulation rate calculated from the level measurement output of the concentrate level sensor, the total source constant ratio valve duty cycle is determined. Based on the aforementioned total source constant ratio valve duty cycle, the volume of source water received by the steam distillation device is controlled, Receiving the aforementioned distillate temperature measurement, To determine the difference between the first target temperature and the measured distillate temperature, In the first operating mode, the first source constant ratio valve is used to separate the source water from the fluid source between the first heat exchanger and the second heat exchanger based on the difference between the first target temperature and the measured distillate temperature. Methods that include...

24. A method for a steam distillation system that provides a distillate at a controlled temperature, the method comprising a steam distillation device configured to receive a certain volume of source water from a fluid source and produce a distillate, the device being A compressor that receives source steam and produces compressed steam, wherein the compressor is supported on a bearing that is lubricated using the condensed compressed steam, A purifier, wherein the purifier is An evaporator that receives source water, the evaporator converts the source water into source water vapor and concentrate, A steam chamber fluidly connected to the evaporator and the compressor, A condenser fluidly connected to the compressor, wherein the condenser converts compressed vapor into a distillate, and A purifier equipped with, A concentrate reservoir and a concentrate level sensor, A source fluid path extending from the fluid source and branching into a first branching source path and a second branching source path, A concentrate flow path, which is fluidly connected to the steam chamber and has concentrate output, A distillate flow path, which is fluidly connected to the condenser and has a distillate output, The first source determinant valve is one level above the first and second branching source paths, A first heat exchanger comprising at least a portion of the distillate flow path and a portion of the first branching source path, A second heat exchanger comprising at least a portion of the concentrate flow path and a portion of the second branching source path, A distillate sensor assembly, which is in communication with the distillate flow path and located downstream of the first heat exchanger, is configured to generate a distillate temperature measurement value. A control system for controlling the steam distillation system and maintaining the concentrate level, wherein the control system is A concentrate controller programmed to control the concentrate valve, A source flow controller programmed to control source flow valves and A control system equipped with To be equipped with, Transmitting signals related to the concentrate controller and source flow controller that indicate the concentrate level, Activating the source fluid valve based on the concentrate level sensor signal at least; Activating the concentrate valve based on the concentrate level sensor signal at least; Determining the total source constant ratio valve duty cycle based on the concentrate accumulation rate and target concentrate accumulation rate calculated from the level measurement output of the concentrate level sensor; Based on the aforementioned total source constant ratio valve duty cycle, the volume of source water received by the steam distillation device is controlled, Receiving the aforementioned distillate temperature measurement, To determine the difference between the first target temperature and the measured distillate temperature, In the first operating mode, the first source constant ratio valve is used to separate the source water from the fluid source between the first heat exchanger and the second heat exchanger based on the difference between the first target temperature and the measured distillate temperature, A method comprising controlling the first and second source control valves in a second operating mode to allocate the entire total source control valve duty cycle to the second source control valve which controls the flow of source water to the second heat exchanger, and releasing the first source control valve which controls the flow of source water to the first heat exchanger for an additional duty cycle below a predetermined limit.

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