Water distillation apparatus, method and system

Abstract

Water distillation apparatuses, methods, and systems are disclosed. A distillation device includes a source fluid input, an evaporator, a condenser, a concentrate level sensor configured to sense a current concentrate level in a concentrate reservoir having an inflow path disposed above the evaporator and having a long axis extending alongside the evaporator, and at least one controller configured to govern a rotational speed of the impeller in a low temperature distillate production state and in a high temperature distillate production state by periodically generating an impeller motor command based on a low temperature distillate production rated speed command in the low temperature distillate production state and a high temperature distillate production rated speed command in the high temperature distillate production state, the low temperature distillate production rated speed command being a faster motor speed command than the high temperature distillate production rated speed command.

Description

[0001] Divisional application

[0002] This application is a divisional application of Chinese patent application filed on March 9, 2019, with application number 201980076323.X and entitled "Water Distillation Apparatus, Method and System". Technical Field

[0003] This invention relates to water distillation, and more particularly, to steam distillation apparatus, methods, and systems. Background Technology

[0004] Vast areas of humanity lack access to reliable clean water. For example, the Canadian International Development Agency reports that approximately 1.2 billion people lack access to safe drinking water. Published reports attribute millions of deaths annually, most of them children, to water-related illnesses. Many water purification technologies are well-known, including carbon filters, chlorination, pasteurization, and reverse osmosis. Many of these technologies are highly susceptible to variations in water quality and cannot address a wide range of common contaminants that may be found in water supplies in developing countries and elsewhere, such as bacteria, viruses, organic matter, arsenic, lead, mercury, and pesticides. Some of these systems require access to a supply of consumables, such as filters or chemicals. Furthermore, some of these technologies are only well-suited for centralized, large-scale water supply systems that require extensive infrastructure and trained operators. Particularly in developing countries, there is a strong desire to produce reliable clean water on a smaller, decentralized scale, regardless of water source availability and without the need for consumables and frequent maintenance.

[0005] Using steam compression distillation to purify water is well-known and can solve many of these problems. However, limited financial resources, scarce technological assets, and low population density make it impossible to establish centralized, large-scale water supply systems in many developing countries. This also limits the availability of sufficient, affordable, and reliable electricity to operate steam compression distillation systems and hinders the ability to properly maintain such systems. In this context, an improved steam compression distillation system and related components that can increase efficiency and productivity while reducing the electricity budget required for system operation and the amount of system maintenance needed can provide a solution. Summary of the Invention

[0006] According to embodiments of this disclosure, a steam distillation system for providing a distillate at a controlled temperature is disclosed. The steam distillation system includes a steam distillation apparatus configured to receive a volume of source water from a fluid source and produce a distillate. The apparatus includes: a concentrate stream path including a concentrate output; and a distillate stream path including a distillate output; at least one source proportioning valve; a first heat exchanger including at least a portion of the distillate stream path; and a second heat exchanger including at least a portion of the concentrate stream path, wherein the first and second heat exchangers are fluidly connected to the fluid source. The system includes: a distillate sensor assembly connected to the distillate stream and located downstream of the first heat exchanger, the distillate sensor assembly being configured to generate a distillate temperature measurement; and a controller configured to control a source proportional valve, the controller being configured to: receive the distillate temperature measurement; determine the difference between the first target temperature and the distillate temperature measurement; and split source water from a fluid source between the first heat exchanger and the second heat exchanger based on the difference between the first target temperature and the distillate temperature measurement.

[0007] According to embodiments of this disclosure, a water purification system for outputting distillate at a controlled temperature may include a distillation apparatus selectively fluidly connected to a fluid source via a set of source proportioning valves. The distillation apparatus may have a concentrate output and a distillate output, respectively coupled to a concentrate stream path and a distillate stream path. The system may further include: a first heat exchanger including a portion of the distillate stream path; and a second heat exchanger including a portion of the concentrate stream path. A flow path from the fluid source may be in heat exchange relationship with each of the first and second heat exchangers. The system may further include a distillate sensor assembly in communication with a portion of the distillate stream path downstream of the portion of the distillate stream path included in the first heat exchanger. The distillate sensor assembly may be configured to generate a distillate temperature measurement. The system may further include a controller configured to control the operation of a source proportional valve in a first operating mode to divert the incoming flow from the fluid source between a first heat exchanger and a second heat exchanger based on the difference between a first target temperature and a distillate temperature measurement.

[0008] In some embodiments, the controller may be configured to determine the total source proportional valve duty cycle, which indicates the amount of incoming flow from a fluid source. In some embodiments, the system may further include a concentrate storage section and a concentrate level sensor. The controller may be configured to determine the total source proportional valve duty cycle based on a concentrate accumulation rate calculated from a level measurement output from the concentrate level sensor and a target concentrate accumulation rate. In some embodiments, the controller may be configured to control the operation of the source proportional valve in a second operating mode to allocate the entire total source proportional valve duty cycle to the source proportional valve that selects the source flow to a second heat exchanger, and to open the source proportional valve that selects the source flow to a first heat exchanger with an increased duty cycle not exceeding a predetermined limit. In some embodiments, the predetermined limit may be selected from a list including 5%, 2%, less than 2%, and zero. In some embodiments, the first operating mode may be a low-temperature distillate production state, while the second operating mode may be a high-temperature distillate production state. In some embodiments, the controller may be configured to open the source proportional valve that selects the source flow to the first heat exchanger based on a second target temperature and the difference between the second target temperature and the current concentrate temperature in the 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 greater than 95°C and less than 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 disposed in an evaporator storage section and in fluid communication with the evaporator of the distillation apparatus. The controller may be configured in a second mode to determine the total source proportional valve duty cycle based at least in part on an evaporator level data signal indicating the water level in the water column of the evaporator storage section. In some embodiments, the first target temperature may be at least 20°C but not greater than 25°C. In some embodiments, the system may further include a source fluid temperature sensor. The controller may be configured to determine the first target temperature based at least in part 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 in communication with a downstream concentrate stream path of a portion of a concentrate stream path included in the second heat exchanger. The concentrate sensor assembly may be configured to generate a concentrate temperature measurement. In some embodiments, the controller is configured to open a source proportional valve that selects the source stream to the second heat exchanger based at least in part on the difference between a third target temperature and the concentrate temperature measurement.In some embodiments, the third target temperature may be a historical average of the concentrate temperature. In some embodiments, the controller may be configured to open the source proportioning valve that gates the source flow to the second heat exchanger based at least in part on a minimum limit. In some embodiments, the minimum limit may be the greater of a predetermined duty cycle of all source proportioning valves or a predetermined percentage of a combined duty cycle. In some embodiments, the predetermined duty cycle may be 5%. In some embodiments, the predetermined duty cycle may be 10%. In some embodiments, the controller may be located in an electronic component box that is thermally connected to the flow path from the fluid source to the second heat exchanger. In some embodiments, the controller may be configured to determine an electronic component box cooling duty cycle command and open the source proportioning valve that gates the source flow to the second heat exchanger based at least in part on the electronic component box cooling duty cycle command. In some embodiments, the electronic component box cooling duty cycle may be determined based at least in part on the difference between a target electronic component box temperature and an electronic component box temperature measurement collected from an electronic component box temperature sensor configured to measure the temperature of the electronic component box and communicate data with the controller. In some embodiments, the distillate sensor assembly may include redundant temperature sensors. In some embodiments, the distillate sensor assembly may include redundant temperature sensors and redundant conductivity sensors. In some embodiments, the first and second heat exchangers may be helical and may be formed by winding the heat exchangers around the exterior of the distillation apparatus.

[0009] According to embodiments of this disclosure, a fluid distillation apparatus may include at least one controller and a source inlet selectively fluidly connected to a fluid source via at least one valve. The fluid vapor distillation apparatus may further include an evaporator fluidly connected to the source inlet. The fluid vapor distillation apparatus may further include a steam chest connected to the evaporator and fluidly connected to a compressor. The fluid vapor distillation apparatus may further include a concentrate storage section attached to the steam chest via an inflow path. The concentrate storage section may be arranged laterally to the steam chest such that at least a portion of the concentrate storage section is at the same height as the steam chest. The fluid vapor distillation apparatus may further include a condenser fluidly connected to the compressor outlet via a straight flow path. The straight flow path may include a condenser inlet having a fenestration section with multiple fenestrations. The fenestrations can establish a flow path from the condenser inlet to the condenser. The fluid vapor distillation apparatus may further include a product process flow storage section connected to the condenser via a product storage section inlet. The product process flow storage section can be arranged laterally relative to the condenser, such that at least a portion of the product process flow storage section is at the same height as the condenser.

[0010] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a plate. The plate may have a section extending into the concentrate storage section at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate storage section and divide the concentrate storage section into a first section and a second shielding section. In some embodiments, the fluid vapor distillation apparatus may further include an exhaust path extending from the concentrate storage section to the vapor chamber. In some embodiments, the exhaust path may be substantially parallel to the inflow path and extend above the inflow path relative to gravity. In some embodiments, the product storage section 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 recessed into the side of the vapor chamber. In some embodiments, the compressor may include an impeller that rotates about an axis that passes through at least a portion of the vapor chamber and is off-center but parallel to the longitudinal axis of the vapor chamber.

[0011] According to another embodiment of this disclosure, a steam distillation apparatus may include a storage tank and an evaporator, a first side of which is in communication with the storage tank. A second side of the evaporator may be in fluid communication with a steam chamber. The steam distillation apparatus may further include a concentrate storage section attached to the steam chamber via an inflow path having a first portion and a second portion. The second portion may be at least partially obstructed. The obstruction may extend into the concentrate storage section in a direction transverse to the first portion and may divide the concentrate storage section into an unobstructed section and an obstructed section. The steam distillation apparatus may further include a float assembly disposed in the obstructed section. The float assembly may be displaced within a displacement range including points of equal height, provided that all steam chamber liquid levels are within a desired steam chamber liquid level range. The steam distillation apparatus may further include a sensor 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. The steam distillation apparatus may further include a compressor having an inlet and an outlet, wherein the inlet is in fluid communication with the steam chamber and the outlet is in fluid communication with a condenser.

[0012] 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 attached to a pivot. In some embodiments, the float assembly may be displaced about a pivot. In some embodiments, the obstruction may extend into the concentrate storage section at an angle substantially perpendicular to a first portion of the inflow path. In some embodiments, the steam distillation apparatus may further include an exhaust path extending from the concentrate storage section to the steam chamber. In some embodiments, the exhaust path may extend parallel to and above the first portion of the inflow path. In some embodiments, the cross-sectional area of ​​the exhaust path may be smaller than the cross-sectional area of ​​the first portion of the inflow path.

[0013] According to another embodiment of this disclosure, a steam distillation apparatus may include a storage tank having a source fluid input. The steam distillation apparatus may further include an evaporator, a first side of which is in fluid communication with the source fluid input via the storage tank, and a second side of which 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 a concentrate as the source fluid travels toward the steam chamber. The steam distillation apparatus may further include a concentrate storage section attached and disposed laterally to the steam chamber. The concentrate storage section may include a concentrate level sensor configured to monitor the level of the concentrate in the steam chamber and generate a data signal indicating the level of the concentrate. The steam distillation apparatus may further include a compressor having: a low-pressure steam inlet in fluid communication with the steam chamber; and a high-pressure steam outlet in 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 outer surfaces of the evaporator. A condenser can be configured to condense a high-pressure vapor stream from a compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of an evaporator. The condenser may include a condensation section and a condensate accumulation or storage section. The steam distillation apparatus may further include an auxiliary condensate storage section in fluid communication with the condensate accumulation section. The auxiliary condensate storage section may be attached to the condenser adjacent to the accumulation surface of the accumulation section. The auxiliary condensate storage section may include a condensate level sensor configured to monitor the condensate level in the accumulation section and generate a data signal indicating the percentage of condensate filling the accumulation section.

[0014] In some embodiments, the accumulation section may have a volume of less than ten liters. In some embodiments, the plurality of outer surfaces may be the outer surfaces of a plurality of evaporator tubes included in an evaporator. In some embodiments, the plurality of outer surfaces may be the outer surfaces of between 90 and 100 evaporator tubes included in an evaporator. In some embodiments, the plurality of outer surfaces may be the outer surfaces of between 70 and 80 evaporator tubes included in an evaporator. In some embodiments, the condensate level sensor may include a float assembly attached to a pivot. In some embodiments, the float assembly may be displaceable about the pivot within a displacement range including a point at the same height as the level range defined by the accumulation section. In some embodiments, the concentrate level sensor may include a float assembly disposed in a shielded section of the concentrate storage section, the shielded section being separated from the unshielded portion of the concentrate storage section by a barrier. In some embodiments, the float assembly may be attached to a pivot, and, provided that all the concentrate levels in the vapor chambers are within the expected range of the vapor chamber level, the float assembly may be displaceable about the pivot within a displacement range including a point at the same height. In some embodiments, the concentrate level sensor may be disposed within a sleeve forming a barrier.

[0015] According to another embodiment of this disclosure, a concentrate level control system for a fluid vapor distillation apparatus may include a source fluid input selectively fluidly communicated with a source fluid storage unit via at least one input valve. The concentrate level control system may further include an evaporator fluidly communicated with both the source input and a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the steam chamber. The concentrate level control system may further include a concentrate storage unit laterally attached to and disposed within the steam chamber via an inflow path, and including an outlet selectively communicated 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 level of concentrate in the steam chamber. The concentrate level control system may also include a controller configured to intentionally change the concentrate level in a predetermined pattern by controlling actuation of at least one inlet valve via a fluid input control loop and analyzing the data signal. The controller can be further configured such that when a data signal indicates that the concentrate level is below a first threshold, the controller actuates the outlet valve to a closed state, and when the concentrate level is above a second threshold, the controller actuates the outlet valve to an open state.

[0016] In some embodiments, a predetermined pattern can generate a sawtooth waveform when the concentrate level is plotted over time. In some embodiments, the period of the sawtooth waveform can be at least partially dependent on a fluid input command from a fluid input control loop. In some embodiments, the fluid input command can be determined based on a predetermined target concentrate production rate. In some embodiments, the controller can be configured to operate in multiple operating states, and the predetermined target concentrate production rate can be state-specific. In some embodiments, the controller can analyze data signals on a predetermined basis. In some embodiments, a predetermined expected range can be assigned to the concentrate level, and a first threshold can be less than or equal to 50% of the maximum level of the expected range. In some embodiments, the first threshold can be between 40% and 50% of the maximum level of the expected range. In some embodiments, a predetermined expected range can be assigned to the concentrate level, and a second threshold can be greater than or equal to 50% of the maximum level of the expected range. In some embodiments, the second threshold can be between 50% and 60% of the maximum level of the expected range. In some embodiments, a predetermined expected range can be assigned to the concentrate level, and a first threshold can be less than or equal to 40% of the maximum level of the expected range. In some embodiments, the first threshold can be between 40% and 30% of the maximum level of the expected range. In some embodiments, a predetermined expected range may be assigned to the concentrate level, and a second threshold may be greater than or equal to 45% of the maximum level within the expected range. In some embodiments, the second threshold may be between 45% and 55% of the maximum level within the expected range. In some embodiments, a predetermined expected range may be assigned to the concentrate level, and the first and second thresholds may be defined as percentages of the maximum level within the expected range. The second threshold may be 4 to 20 percentage points larger than the first threshold. In some embodiments, the concentrate is destined for a mixing tank.

[0017] According to another embodiment of this disclosure, a method for controlling the level of concentrate in a distillation apparatus and verifying fluid flow within the distillation apparatus may include: inputting source fluid into the distillation apparatus through at least one inlet valve. The method may further include: evaporating at least a portion of the source fluid to generate steam and concentrate as it travels toward a steam chamber. The method may further include: collecting the concentrate in a concentrate storage section, wherein the concentrate storage section is attached and disposed transversely to the steam chamber via an inflow path. The method may further include: providing a data signal indicating the level of concentrate in the steam chamber from a concentrate level sensor disposed in the concentrate storage section. The method may further include: using a controller to change the concentrate level in a predetermined pattern by controlling the actuation of at least one inlet valve and analyzing the data signal via a fluid input control loop, and actuating the outlet valve of the concentrate storage section to a closed state when the data signal indicates that the concentrate level is below a first threshold, and actuating the outlet valve of the concentrate storage section to an open state when the concentrate level is above a second threshold.

[0018] In some embodiments, changing the concentrate level may include: changing the concentrate level to produce a sawtooth waveform when plotting the concentrate level 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 predetermined expected range to the concentrate level and setting a first threshold to be 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 between 40% and 50% of the maximum level of the expected range. In some embodiments, the method may further include: assigning a predetermined expected range to the concentrate level and setting a second threshold to be greater than or equal to 50% of the maximum level of the expected range. In some embodiments, setting the second threshold includes setting the second threshold between 50% and 60% of the maximum level of the expected range. In some embodiments, the method may further include: assigning a predetermined expected range to the concentrate level and setting a first threshold to be 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 between 40% and 30% of the maximum level of the expected range. In some embodiments, the method may further include: assigning a predetermined expected range to the concentrate level and setting a second threshold to be greater than or equal to 45% of the maximum level of the expected range. In some embodiments, setting the second threshold includes setting the second threshold between 45% and 55% of the maximum material level within a desired range. In some embodiments, the method may further include: allocating a predetermined desired range of concentrated material levels, and setting the first threshold and the second threshold as percentages of the maximum material level within the desired range, wherein the second threshold is 4 to 20 percentage points larger than the first threshold.

[0019] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation apparatus to a desired temperature may include a source fluid input selectively fluidly communicated with a source fluid storage unit via a set of fluid input valves. The system may further include an evaporator fluidly communicated with both the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The system may further include a condenser fluidly communicated with the compressor and configured to convert pressurized vapor from the compressor into condensate. The system may further include a condensate stream path and a concentrate stream path, each including a corresponding first heat exchanger and a second heat exchanger. The first and second heat exchangers may each include a heat exchange section from the source fluid stream path of the source fluid storage unit. The heat exchange section may be 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 in the condensate stream path downstream of the first heat exchanger. The system may further include a controller configured to actuate an input source valve group based on a first control loop and a second control loop, and to allocate a total open state time among all input source valves to regulate the condensate temperature to a desired temperature, wherein the first control loop controls the total open state time of all input source valves in the input source valve group, and the second control loop receives a data signal and the desired temperature.

[0020] In some embodiments, the heat exchange sections of the source fluid flow paths within the first and second heat exchangers may be configured to flow countercurrently to their respective condensate and concentrate flow paths. In some embodiments, the system may further include a destination device that is in fluid communication with the condensate flow path via a point-of-use valve. In some embodiments, the requested 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 PID control loops 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 allocated based on an estimated total on-state 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 within the distillation apparatus. The first control loop may be configured to receive a target concentrate level and a current concentrate level data signal as inputs to the first control loop. In some embodiments, the controller may be further configured to adjust the heater duty cycle based at least in part on the total open time of all input source valves in the input source valve group. In some embodiments, the controller may be configured to increase the heater duty cycle as the open time of all input source valves in the input source valve group increases.

[0021] According to another embodiment of this disclosure, a method for controlling the temperature of a product process flow in a distillation apparatus to a requested temperature may include: controlling the flow rate of a source fluid input to the distillation apparatus by actuating a set of source fluid valves using a controller. 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 apparatus through corresponding condensate and concentrate streams. The method may further include: exchanging heat between the source fluid flow and the condensate stream in a first heat exchanger, and exchanging heat between the source fluid flow and the concentrate stream in a second heat exchanger. The method may further include: providing a condensate temperature data signal to the controller from a temperature sensor located downstream of the first heat exchanger in the condensate stream. The method may further include: determining the total open state time of fluid input valve groups among fluid input valve groups based on a first control loop; and allocating the total open state time among fluid input valve groups based on a second control loop, wherein the second control loop receives the temperature data signal and the requested temperature.

[0022] In some embodiments, the method may further include: flowing condensate and concentrate in a direction countercurrent to the flow of the source fluid through a condensate path and a concentrate path. In some embodiments, the method may further include: supplying condensate to a destination device via an actuated point-of-use valve downstream of a temperature sensor. In some embodiments, the requested 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: using the condensate to mix dialysate. 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 a first control loop and a second control loop 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 a second control loop. In some embodiments, the method may further include: determining the feedforward term based on an estimated allocation of the total open state time. In some embodiments, the method may further include: inputting the current concentrate level and the target concentrate level provided by a concentrate level sensor to the first control loop. In some embodiments, the method may further include: adjusting the heater duty cycle based at least in part on the total open state time of all input source valves in the input source valve group. In some embodiments, adjusting the heater duty cycle may include increasing the heater duty cycle when the open state time of all input source valves in the input source valve group is increased.

[0023] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation apparatus to a desired temperature may include a first source fluid input and a second fluid source input, the first and second source fluid inputs being selectively fluidly communicated with a source fluid storage unit via a first set of fluid input valves and a second set of fluid input valves, respectively. The system may further include an evaporator fluidly communicated with the first and second source fluid inputs and with a compressor. The evaporator may have a heating element to convert the source fluid from the first and second source fluid inputs into a vapor stream and a condensate stream as the source fluid travels toward the compressor. The system may further include a condenser fluidly communicated with the compressor. The condenser may be configured to convert pressurized vapor from the compressor into condensate. The system may further include a condensate stream path and a condensate stream path, the condensate stream path and the condensate stream path including respective first and second heat exchangers. The first and second heat exchangers may each include a heat exchange section of the source fluid stream path from the source fluid storage unit downstream of the source fluid input valve assembly. 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 in the condensate flow path downstream of the first heat exchanger. The system may also include a controller configured to actuate a first set of input source valves based on a first control loop and a second control loop, and to allocate a total open time among all input source valves in the first set of input source valves to regulate the condensate temperature to a desired temperature, wherein the first control loop controls the total open time of all input source valves in the first set of input source valves, and the second control loop receives the data signal and the desired temperature. The controller may be configured to monitor at least one process variable and actuate a second set of input source valves when one of the at least one process variable is outside a predetermined threshold.

[0024] 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 source fluid input and the second source fluid input 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 hot fluid input. In some embodiments, at least one process variable monitored by the controller may be the heating element duty cycle. In some embodiments, the at least one process variable monitored by the controller may be the output of a first control loop. In some embodiments, the at least one process variable may be the compressor speed. In some embodiments, the heat exchange section of the source fluid flow path may be a common flow path for fluids from the first source fluid input and the second source fluid input.

[0025] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation apparatus to a desired temperature may include a source fluid input selectively fluidly communicated with a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator selectively fluidly communicated with the source fluid input via a bypass valve and fluidly communicated with a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The system may further include a condenser fluidly communicated with the compressor and configured to convert pressurized vapor from the compressor into condensate. The system may further include a condensate stream path and a concentrate stream path, each including a corresponding first heat exchanger and a second heat exchanger. The first and second heat exchangers may each include a heat exchange section of the source fluid stream path from the source fluid reservoir 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 in the condensate stream path downstream of the first heat exchanger. The system may further include a controller configured to actuate the input source valve group based on a first control loop and a second control loop, and to allocate a total open state time among all input source valves to regulate the condensate temperature to a desired temperature. The first control loop controls the total open state time of all input source valves in the input source valve group, and the second control loop receives a data signal and the desired temperature. A bypass valve may be located in the source fluid flow path downstream of the heat exchange section of the source fluid flow path. The bypass valve may have a diversion valve state that directs fluid from the source storage section to the discharge destination. The controller may be configured to actuate the bypass valve to the diversion valve state when it determines that 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, the at least one process variable may be the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, the at least one process variable may be defined at least in part by the condensate temperature and the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, when the bypass valve is in a diverter state, the controller may change the duty cycle of at least one of the input source valves. In some embodiments, when the bypass valve is in a diverter state, the controller may increase the duty cycle of at least one of the input source valves. In some embodiments, when the bypass valve is in a diverter state, the controller may change the duty cycle of at least one input source valve to 90% to 100%. In some embodiments, one of the at least one input source valve may be a valve that controls the flow rate of the source fluid through the heat exchange section of a first heat exchanger.

[0027] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation system to a desired temperature may include a source fluid input selectively fluidly communicated with a source fluid storage unit via a set of fluid input valves. The system may further include a distillation apparatus configured to generate a concentrated stream and a condensate stream. The system may further include a condensate stream path and a concentrated stream path, each including a corresponding first heat exchanger and a second heat exchanger. The first and second heat exchangers may each include a heat exchange section from the source fluid flow path of the source fluid storage unit, 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 stream path downstream of the first heat exchanger. The system may further include a point-of-use device selectively communicated with the condensate stream path. The point-of-use device may have an outlet fluid path for discharging the fluid generated by the point-of-use device. The outlet fluid path may have a third heat exchanger including a heat exchange section of a branch of the source fluid flow path. The system may further include a controller configured to actuate an input source valve assembly based on a first control loop and a second control loop and based on at least one process variable, wherein the first control loop and the second control loop control the flow of source fluid through the heat exchange sections of the first and second heat exchangers. When the at least one process variable is outside a predetermined threshold, the controller may actuate a branch valve to a branch of the source fluid flow path.

[0028] 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, the at least one process variable may be the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, the at least one process variable may be defined at least in part by the condensate temperature and the source fluid temperature sensed by the 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, a branch of the source fluid flow path may be located upstream of the heat exchange section of the source fluid flow path in the first heat exchanger and the second heat exchanger. In some embodiments, the output fluid may be dialysate effluent.

[0029] According to another embodiment of this disclosure, a condensate accumulation rate control system for controlling the condensate accumulation rate within a distillation apparatus may include a source fluid input selectively fluidly communicated with a source fluid storage section via a set of fluid input valves. The system may further include an evaporator fluidly communicated with the source input and with a compressor having an impeller operatively coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a condensate stream as the source fluid travels toward the compressor. The system may further include a condenser in heat transfer relationship with a plurality of outer surfaces of the evaporator. The condenser may be configured to condense a high-pressure vapor stream from the compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The system may further include a condensate level sensor configured to sense the current condensate level in the condenser. The system may further include at least one controller configured to control the impeller rotational speed by periodically generating impeller motor commands based on a last motor speed command, a motor speed target, and speed command increment limits. The target motor speed can be calculated using a control loop that receives the current condensate level and the desired condensate level as inputs.

[0030] In some embodiments, the speed command increment limit may be ≤10 rpm / sec (revolutions per minute per second). In some embodiments, the speed command increment limit may be ≤5 rpm / sec. In some embodiments, the controller may be configured to compare the impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and when the impeller motor command is less than the minimum command speed threshold, the controller adjusts the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold, and when the impeller motor command is greater than the maximum command speed threshold, the controller adjusts the impeller motor command to a modified impeller motor command equal to the maximum command speed threshold. In some embodiments, the minimum command speed threshold is between 1500 rpm and 2500 rpm. In some embodiments, the maximum command speed threshold is calculated whenever 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, wherein 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 may be limited to a predetermined value. In some embodiments, the predetermined value may be between 4500 rpm and 6500 rpm. In some embodiments, the predetermined value may be 5000 rpm. In some embodiments, the predetermined value may be approximately 2.5 times larger than the minimum command speed threshold.

[0031] According to another embodiment of this disclosure, a method for controlling the condensate accumulation rate within a distillation apparatus may include providing a source fluid input to the distillation apparatus. The method may further include: evaporating at least a portion of the source fluid input to low-pressure steam in an evaporator. The method may further include: compressing the low-pressure steam into 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 the evaporator. The method may further include providing a condensate level within the condenser, sensed by a condensate level sensor, to a controller. 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 impeller rotational speed by periodically generating impeller motor commands based on a last motor speed command, the motor speed target, and speed command increment limits.

[0032] 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 when the impeller motor command is less than the minimum command speed threshold, adjusting the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold, and when the impeller motor command is greater than the maximum command speed threshold, adjusting the impeller motor command to a modified impeller motor command equal to the maximum command speed threshold. In some embodiments, the minimum command speed threshold may be between 1500 rpm and 2500 rpm. In some embodiments, the minimum command speed threshold may be 2000 rpm. In some embodiments, the method may further include: calculating a maximum command speed threshold whenever 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 a temperature data signal indicating the motor temperature to the controller from a motor temperature sensor, and providing a power factor correction data signal indicating the current power factor correction current to the controller from a monitoring circuit. In some embodiments, the method may further include: calculating a maximum command speed threshold based on temperature data signals and power factor correction data signals. In some embodiments, the method may further include: setting an upper limit of the maximum command speed threshold to a predetermined value. In some embodiments, the predetermined value may be between 4500 rpm and 6500 rpm. In some embodiments, the predetermined value may be 5000 rpm. In some embodiments, the predetermined value may be a minimum command speed threshold or may be approximately 2.5 times larger than the minimum command speed threshold.

[0033] According to embodiments of this disclosure, a fluid vapor distillation apparatus having a first separable section and a second separable section may include a source inlet selectively fluidly connected to 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 in fluid communication with the reservoir. The apparatus may further include a steam chamber coupled to the evaporator and in fluid communication with a compressor. The apparatus may further include a condenser in fluid communication with the compressor outlet. The condenser may surround the plurality of tubes. The apparatus may further include a support plate 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 member. In a first state, the first and second sections may be held together by one or more fasteners, while in a second state, the first and second sections are separated from each other, in which the first section is rotatable about a pivot.

[0034] In some embodiments, the at least one mounting member may be an isolation mounting member. In some embodiments, the first section may include a storage tank, 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 the relaxed state and a second position when the biasing member is in the 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.

[0035] According to another embodiment of this disclosure, the distillation apparatus may include a source fluid input selectively fluidly communicated with a source fluid storage unit via a set of fluid input valves. The apparatus may further include an evaporator fluidly communicated with both the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a condensate stream as the source fluid travels toward the compressor. The apparatus may further include a condenser fluidly communicated with the compressor and configured to convert pressurized vapor from the compressor into condensate. The apparatus may further include a condensate stream path and a condensate stream path, each including a corresponding first and second heat exchanger. The first and second heat exchangers may each include a heat exchange section from the source fluid stream path of the source fluid storage unit. The heat exchange section 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 in the condensate stream path downstream of the first heat exchanger. The device may further include a controller configured to actuate the input source valve group based on a first multi-mode control loop, wherein the first multi-mode control loop generates multiple temporary overall open state commands for all input source valves in the input source valve group. The controller may be configured to actuate the input source valve group based on a slider, wherein the slider generates a single overall open state command from multiple temporary commands. The controller may be configured to actuate the input source valve group based on a second control loop, which receives a data signal and a temperature setpoint, and distributes the overall open state command among all input source valves to regulate the condensate temperature to the temperature setpoint.

[0036] In some embodiments, the heat exchange sections of the source fluid flow paths within the first and second heat exchangers may be configured to flow counter-currently 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 depend on the state. In some embodiments, the apparatus further includes a destination device that is in fluid communication 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 multi-mode control loop and the second control loop may include a PID control loop. In some embodiments, the gain of at least one of the PID control loops may be zero. In some embodiments, the number of temporary total open state commands may be adjusted by the output of at least one regulator control loop. In some embodiments, the distillation apparatus may further include a reservoir. The reservoir may be located between the source input and the evaporator. One of the at least one regulator control loops may be configured to generate an output based on a target reservoir temperature and a current reservoir temperature measured by a reservoir temperature sensor, wherein the reservoir temperature sensor 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 regulator control loop may be configured to generate an output based on a target steam temperature and a current steam temperature measured by a steam temperature sensor, wherein the steam temperature sensor is configured to generate a data signal representing the temperature of the steam flow. In some embodiments, the apparatus may further include a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level within the distillation unit. The controller may be configured to determine the current blowdown rate from the concentrate level data signal. A first multi-mode control loop may be configured to receive the target blowdown rate and the current blowdown rate data signals as inputs. In some embodiments, at least one of the temporary total open state commands may be a first production temperature state command, and at least one of the temporary total open state commands may be a second production temperature state command. In some embodiments, the apparatus may further include an evaporator level sensor configured to output an evaporator data signal. The controller may be configured to generate at least one of the temporary total open state commands based at least in part on the input 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 derivative controller. In some embodiments, the derivative controller may be a PID controller in which the gain of the D term is at least an order of magnitude greater than that of the P and I terms.

[0037] According to another embodiment of this disclosure, a steam distillation apparatus may include a storage tank having a source fluid input. The apparatus may further include an evaporator, a first side of which is in fluid communication with the source fluid input via the storage tank, and a second side of which 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 a concentrate. During operation, the liquid level in the evaporator may be uneven. The apparatus may further include an evaporator storage section disposed transversely to the evaporator and in fluid communication with the evaporator via the storage tank. The evaporator storage section may include a level sensor configured to monitor the water level in the water column of the evaporator storage section and generate a data signal indicating the water level. The apparatus may further include a compressor having a low-pressure steam inlet and a high-pressure steam outlet, wherein the low-pressure steam inlet is in fluid communication with the steam chamber, and the high-pressure steam outlet is in fluid communication with the condenser via a condenser inlet. The apparatus may further include a condenser that is in heat transfer relationship with a plurality of outer surfaces of the evaporator. The condenser can be configured to condense a high-pressure vapor stream from a compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The condenser may include a condensation section and a condensate accumulation section. The device may further include a processor configured to actuate a set of input source valves to the source fluid input, partially based on data signals.

[0038] In some embodiments, the level sensor may include a movable member capable of displacement within a displacement range less than the height of the evaporator storage section. In some embodiments, the level sensor may include a movable member capable of displacement within a displacement range extending from a first end of the evaporator storage section to at least the midpoint of the evaporator storage section. The displacement range may be a distance less than 70% of the height of the evaporator storage section. In some embodiments, the first end may be the end of the evaporator storage section furthest from the storage tank. In some embodiments, the evaporator storage section may communicate with the steam chamber via an exhaust path extending from the first end of the evaporator storage section. In some embodiments, the exhaust path may extend from the evaporator storage section to a concentrate storage section, which is attached and disposed laterally to the steam chamber. In some embodiments, the height of the evaporator storage section may be greater than the height of the evaporator. In some embodiments, the processor may be configured to determine the total open state time of the input source valve group in part based on a target water column level determined via analysis of data signals and the current water column level. In some embodiments, the processor may be configured to determine the total open state time of the input source valve group in part based on the output of a PID controller, wherein the PID controller receives the target water column level and the current water column level as inputs. In some embodiments, the gain of at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain of the D term of the PID controller may be at least an order of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, the gain of the D term of the PID controller may be two orders of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, the processor may be configured to determine the total open state time in part based on a target discharge rate and a current discharge rate, indicated by a discharge level data signal generated by a discharge level sensor attached to the discharge storage section of the steam chamber. In some embodiments, the processor may be configured to determine the total open state command in part based on the output of at least one regulator control loop. In some embodiments, one of the at least one regulator control loop may be configured to generate an output based on a target tank temperature and a current tank temperature measured by a tank temperature sensor configured to generate a data signal representing the temperature of the fluid in the tank. In some embodiments, one of the at least one regulator control loop may be configured to generate an output based on a target steam temperature and a current steam temperature measured by a steam temperature sensor configured to generate a data signal representing the steam flow temperature. In some embodiments, the controller may be configured to change the overall open state command of the input source valve group in response to a change in the water column level indicated by the data signal. In some embodiments, the controller may be configured to change the overall open state command of the input source valve group proportionally to the rate of change of the water column indicated by the data signal.

[0039] According to another embodiment of this disclosure, a method for controlling the flow rate of a source fluid into a distillation apparatus may include establishing a non-uniform liquid level in the evaporator of the distillation apparatus. The method may further include: sensing the liquid column level in an evaporator storage section using a first level sensor, wherein the evaporator storage section is in fluid communication with the evaporator and is positioned at the same height as the evaporator. The method may further include: sensing the level of concentrated material in a concentrate storage section in fluid communication with the evaporator using a second level sensor. The method may further include: generating a source inlet valve opening time command using a processor, based at least in part on the concentrated material level, a target concentrate accumulation rate, and the difference between the liquid column level and the target liquid column level. The method may further include: commanding multiple source inlet valves to open based on the source inlet valve opening time command.

[0040] In some embodiments, sensing the liquid column level may include displacing a movable member within a displacement range less than the height of the evaporator reservoir. In some embodiments, sensing the liquid column level may include displacing the movable member within a displacement range extending from a first end of the evaporator reservoir to at least the midpoint of the evaporator reservoir. The displacement range may be a distance less than 70% of the height of the evaporator reservoir. In some embodiments, the first end may be the end of the evaporator reservoir furthest from the distillation apparatus. In some embodiments, the method may further include venting the evaporator reservoir to a vapor chamber of the distillation apparatus disposed above the evaporator via a venting path. In some embodiments, the venting path may extend from the evaporator reservoir to a concentrate reservoir, which is attached and disposed laterally to the vapor chamber. In some embodiments, generating a source inlet valve opening time command may include inputting a difference to a PID controller. In some embodiments, the gain of at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain of the D term of the PID controller may be at least an order of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, the gain of the D term of the PID controller may be two orders of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, generating a source inlet valve opening time command may include determining the current concentrate accumulation rate based on the concentrate level and calculating the difference between the target concentrate rate and the current concentrate accumulation rate. In some embodiments, generating a source inlet valve opening time command may include generating the output of at least one regulator control loop. In some embodiments, the method may further include: sensing the current tank temperature using a tank temperature sensor, and generating the output of at least one regulator control loop includes generating the output based on the target tank temperature and the current tank temperature. In some embodiments, the method may further include: sensing the temperature of the vapor flow in the distillation apparatus using a vapor temperature sensor. In some embodiments, generating the output of at least one regulator controller may include generating the output based on the target vapor temperature and the current vapor temperature. In some embodiments, the method may further include: changing the source inlet valve opening time command in response to a change in the liquid column level. In some embodiments, the method may further include: changing the source inlet valve opening time command proportionally to the rate of change of the liquid column level.

[0041] According to another embodiment of this disclosure, a fluid vapor distillation apparatus may include at least one controller. The apparatus may further include a source inlet selectively fluidly connected to a fluid source via at least one valve. The apparatus may further include an evaporator fluidly connected to the source inlet. The apparatus may further include a steam chamber coupled to the evaporator and fluidly connected to a compressor. The outer surface of the steam chamber may form part of an inlet flow path to the compressor and part of an outlet flow path to the compressor outlet. The apparatus may further include a concentrate storage section. The concentrate storage section may be attached to the steam chamber via an inflow path and disposed transversely to the steam chamber, such that at least a portion of the concentrate storage section is at the same height as the steam chamber. The apparatus may further include a condenser fluidly connected to the compressor outlet via a straight flow path. The straight flow path may include a condenser inlet fixedly attached to a sheet having a first side defining a portion of the steam chamber and an opposite side defining a portion of the condenser. The device may further include a product process flow storage section connected to the condenser via a product storage section inlet and disposed transversely to the condenser, such that at least a portion of the product process flow storage section is at the same height as the condenser.

[0042] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a wall extending into the concentrate storage section at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate storage section and divide the concentrate storage section into a first section and a second shielding section. In some embodiments, the obstruction may include at least one vent. In some embodiments, the product storage section inlet may be adjacent to the product accumulation surface of the condenser. In some embodiments, the compressor may be driven by a motor partially disposed within a receiving well recessed into the side of the steam chamber. In some embodiments, the compressor may include an impeller that rotates about an axis extending laterally relative to the steam chamber and parallel to the longitudinal axis of the steam chamber.

[0043] According to another embodiment of this disclosure, the distillation apparatus may include a source fluid input selectively fluidly communicated with a source via a set of fluid inlet valves. The apparatus may further include an evaporator fluidly communicated with the source input and with a compressor having an impeller operatively coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The apparatus may further include a condenser in heat transfer relationship with a plurality of outer surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor stream from the compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The apparatus may further include a concentrate level sensor configured to sense the current concentrate level in a concentrate storage section having an inflow path disposed above the evaporator and having a long axis extending side-by-side along the evaporator. The device may further include at least one controller configured to periodically generate impeller motor commands based on a rated speed command for low-temperature distillate production in a low-temperature distillate production state and a rated speed command for high-temperature distillate production in a high-temperature distillate production state, thereby controlling the impeller speed in both the low-temperature and high-temperature distillate production states. The rated speed command for low-temperature distillate production may be a motor speed command that is faster than the rated speed command for high-temperature distillate production.

[0044] In some embodiments, the impeller motor command can be adjusted based on a data signal from a concentrate level sensor, wherein the data signal indicates the level of concentrate in the concentrate storage compartment. In some embodiments, the adjustment can be limited by an impeller motor command increment limit. In some embodiments, the impeller motor command increment limit can be ≤10 rpm / sec. In some embodiments, the impeller motor command increment limit can be ≤5 rpm / sec. In some embodiments, when the data signal indicates that the level of concentrate in the concentrate storage compartment is greater than a first threshold, the impeller motor command can be decreased. In some embodiments, the first threshold can be defined as a concentrate level at which the concentrate storage compartment is at a predetermined fill value of 65% to 80% of its full value. In some embodiments, when the data signal indicates that the level of concentrate in the concentrate storage compartment is greater than the first threshold, the impeller motor command can be maintained at a value no greater than the previous command. In some embodiments, the first threshold can be defined as a concentrate level at which the concentrate storage compartment is at a predetermined fill value of 65% to 80% of its full value. In some embodiments, when the data signal indicates that the level of concentrate in the concentrate storage compartment is greater than a second threshold, the impeller motor command can be increased. In some embodiments, the rated high-temperature distillate production rate command may be a calibrated value defined during manufacturing. In some embodiments, the rated high-temperature distillate production rate command may be less than 80% and greater than 45% of the rated low-temperature distillate production rate command. In some embodiments, the rated low-temperature distillate production rate command may be 4500 rpm. In some embodiments, the rated low-temperature distillate production rate command may be 5000 rpm.

[0045] According to another embodiment of this disclosure, a method for controlling a compressor in a distillation apparatus may include: opening at least one fluid inlet valve to deliver a source fluid from a fluid source to a storage tank in the distillation apparatus. The method may further include: converting the source fluid into a concentrated stream and a vapor stream in an 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 rated speed command for low-temperature distillate production in a low-temperature distillate production state, and may be based on a rated speed command for high-temperature distillate production in a high-temperature distillate production state. The rated speed command for low-temperature distillate production may be a motor speed command that is faster than the rated speed command for high-temperature distillate production. 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 compressor impeller to rotate at the final command speed. The method may further include: compressing the vapor stream via the compressor. The method may further include: condensing the vapor stream into condensate, and transferring heat to the evaporator as the vapor stream condenses.

[0046] In some embodiments, the method may further include: sensing the level of concentrated material in a concentrate storage compartment fluidly in 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 concentrated material level. In some embodiments, determining the adjustment may include reducing the compressor speed command when the concentrated material level is greater than a first threshold. In some embodiments, the first threshold may be defined as a concentrated material level at which the concentrate storage compartment is at a predetermined fill value of 65% to 80% of its full value. In some embodiments, determining the adjustment may include: maintaining the final command speed at a final command speed no greater than a previous command speed when the concentrated material level is greater than the first threshold. In some embodiments, determining the adjustment may include: reducing the compressor speed command when the concentrated material level is greater than 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 incremental limit. In some embodiments, the incremental limit may be ≤10 rpm / sec. In some embodiments, the incremental limit may be ≤5 rpm / sec. In some embodiments, the high-temperature distillate production rated speed command may be a calibration value defined during manufacturing. In some embodiments, the rated production rate command for high-temperature distillate can be less than 80% and greater than 70% of the rated production rate command for low-temperature distillate. In some embodiments, the rated production rate command for low-temperature distillate can be 4500 rpm.

[0047] According to another embodiment of this disclosure, the distillation apparatus may include a reservoir selectively fluidly connected to a source via a set of fluid inlet valves. The apparatus may further include at least one heating element and at least one reservoir temperature sensor within the reservoir. 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 fluidly connected to the reservoir and a second side fluidly connected to a compressor, wherein the compressor has an impeller operatively coupled to an impeller motor. The evaporator may be configured to convert source fluid from a source fluid inlet into a vapor stream and a concentrate. The apparatus may further include a condenser in thermal transfer relationship with a plurality of outer surfaces of the evaporator. The condenser may be configured to condense a high-pressure vapor stream from the compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The apparatus may further include a concentrate level sensor configured to sense the current concentrate level in a concentrate storage section, wherein the concentrate storage section has an inflow path disposed above the evaporator and has a long axis extending side-by-side along the evaporator. The device may further include a steam temperature sensor disposed 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 based at least in part on the target temperature of the steam flow, the steam temperature data signal, the tank temperature data signal, and a total source opening command for the fluid input valve assembly.

[0048] In some embodiments, the target temperature of the steam stream may be 108°C. In some embodiments, the controller may be configured to adjust the duty cycle command to meet 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 based at least in part on the power consumption of the compressor. In some embodiments, the controller may be configured to calculate the limit of the duty cycle command by determining the power consumption of the compressor and subtracting the power consumption of the compressor from a predetermined power value. In some embodiments, the predetermined power value may be defined as the maximum total power of the system. In some embodiments, the duty cycle command may be limited to a predetermined maximum duty cycle. In some embodiments, the predetermined maximum duty cycle may be no greater than 90% of the duty cycle. In some embodiments, the target temperature of the steam stream may be state-specific. In some embodiments, the target temperature in a low-temperature distillate production state may be greater than the target temperature in a high-temperature distillate production state. In some embodiments, the target temperature of the steam stream in a first state may be 108°C, and the target temperature of the steam stream in a 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 for determining the duty cycle command based on the total source open command of the fluid input valve assembly and at least one thermodynamic property of the source fluid. In some embodiments, the thermodynamic property may be the specific heat of the source fluid. In some embodiments, the target temperature of the vapor flow may be 111°C to 112°C.

[0049] According to embodiments of this disclosure, a method for heating a fluid in a distillation apparatus may include opening at least one fluid inlet valve to deliver source fluid from a fluid source to a reservoir in the distillation apparatus. 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 steam temperature of a vapor stream generated from the source fluid. The method may further include: comparing the steam temperature with a target steam temperature using a processor. The method may further include: inputting the difference between the steam temperature and the target steam temperature to a first controller and generating a first controller output. The method may further include: providing input to a second controller based at least in part on the first controller output and the reservoir temperature, and generating a second controller output. The method may further include: changing the second controller output to a modified second controller output based on the total open state time of the at least one fluid inlet valve. The method may further include: commanding the duty cycle of a heating element in the reservoir based on the modified second controller output and at least one limit.

[0050] In some embodiments, the target steam 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, the at least one limit may include a limit based at least in part on the power consumption of the compressor in the distillation apparatus. In some embodiments, the method may further include calculating one of the at least one limits by determining the power consumption of the compressor and subtracting the power consumption of the compressor from a predetermined power value. In some embodiments, the predetermined power value may be defined as the maximum total power of the system. In some embodiments, the at least one limit may include a predetermined maximum duty cycle limit. In some embodiments, the predetermined maximum duty cycle may be no greater than a 90% duty cycle. In some embodiments, the target steam temperature of the steam stream may be state-specific. In some embodiments, the target temperature in a low-temperature distillate production state may be greater than the target temperature in a high-temperature distillate production state. In some embodiments, the target temperature in a first state may be 4°C higher than the target temperature in a 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 the total source opening command of the at least one fluid input valve and at least one thermodynamic property of the source fluid. In some embodiments, the thermodynamic property may be the specific heat of the source fluid.

[0051] According to embodiments of this disclosure, a water distillation apparatus may include a storage tank selectively fluidly connected to a fluid source via a set of source proportioning valves. The apparatus may further include an evaporator fluidly connected to the storage tank. The apparatus may further include a steam chamber coupled to the evaporator and fluidly connected to a compressor. The apparatus may further include a concentrate storage section attached to the steam chamber via an inflow path and having a concentrate level sensor configured to generate a concentrate level data signal indicating the fill percentage of the concentrate storage section. The concentrate storage section may be coupled to a concentrate flow path. The apparatus may further include a condenser coupled to the compressor outlet and fluidly connected to a condensate flow path. The apparatus may further include a first heat exchanger and a second heat exchanger, each including a heat exchange section of a source fluid flow path from the fluid source. The heat exchange section of the first heat exchanger may exchange heat with the condensate flow path, while the heat exchange section of the second heat exchanger may exchange heat with the concentrate flow path. The heat exchange section of the source fluid flow path may be downstream of the source proportioning valves. The device may further include at least one distillate sensor in communication with the condensate flow path at a point downstream of the first heat exchanger. The device may further include a controller configured to determine the total open state time of the source proportional valves based at least in part on a concentrate data signal and a target concentrate rate. The controller may be configured to assign a percentage of the total open state command to each source proportional valve based on at least one distillate sensor data signal from at least one distillate sensor.

[0052] In some embodiments, the condenser may include a condenser section and a condensate accumulation section. In some embodiments, the condenser may be in fluid communication with a condensate storage section including a condensate level sensor configured to monitor the level of condensate in the condensate storage section and generate a condensate data signal indicating the fill percentage of the condensate accumulation section. The condensate storage section may be located between the condenser and the concentrate stream. In some embodiments, a controller may be configured to maintain a target fill percentage of the condensate accumulation section based on the output of a PID control loop that uses the target fill percentage and the difference between the target fill percentage and the current fill percentage as indicated by the condensate data signal as input. In some embodiments, the target fill percentage may be equal to at least one liter and less than two liters. In some embodiments, the condenser may be in fluid communication with a condensate storage section including a condensate level sensor configured to monitor the level of condensate in the condensate storage section and generate a condensate data signal indicating the fill percentage of the condensate storage section. The condensate storage section is located between the condenser and the concentrate stream. In some embodiments, at least one distillate sensor may include a temperature sensor. In some embodiments, the 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 assign a percentage of the total open state command to each source proportional valve based on a control loop, wherein the control loop uses a target condensate temperature and the current condensate temperature as inputs. In some embodiments, the target temperature may be at least 35°C but not more than 40°C. In some embodiments, the target temperature may be at least 20°C but not more than 30°C. In some embodiments, the target temperature may be at least 90°C but 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 the range of 20°C to 25°C.

[0053] According to another embodiment of this disclosure, the distillation system may include a distillation apparatus selectively fluidly connected to a fluid source via a set of source proportioning valves. The distillation apparatus may have a concentrate output coupled to a concentrate path and a condensate output coupled to a condensate path. The system may further include a first heat exchanger and a second heat exchanger, each including a heat exchange portion of a source fluid path from a fluid source downstream of the source proportioning valves. The heat exchange portion of the first heat exchanger may be in heat exchange relationship with the condensate path, while the heat exchange portion of the second heat exchanger may be in heat exchange relationship with the concentrate path. Each heat exchanger may have a dedicated source proportioning valve. The system may further include a condensate sensor assembly in communication with the condensate path at a point downstream of the first heat exchanger. The system may further include a controller configured to, in a first operating mode, distribute a command flow of source fluid from the fluid source between the source proportioning valves based on the difference between a first target temperature and a current concentrate temperature received by the controller from the condensate sensor assembly. In the second mode, the controller can be configured to distribute all command flows to the source proportional valve dedicated to the second heat exchanger and open the source proportional valve dedicated to the first heat exchanger with a duty cycle that may not exceed a predetermined limit.

[0054] In some embodiments, the predetermined limit may be 5%. In some embodiments, the predetermined limit may be 2%. In some embodiments, the predetermined limit may be 0%. In some embodiments, the condensate sensor assembly may include redundant temperature sensors. In some embodiments, the first heat exchanger and the second heat exchanger may be helical and formed by winding the heat exchangers around the exterior of the distillation apparatus. 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 may be at least 35°C but not greater than 40°C. In some embodiments, the first target temperature may be at least 20°C but less than 25°C. In some embodiments, the controller may be configured to open a source proportional valve dedicated to the first heat exchanger based on a second target temperature and the difference 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 greater than 95°C and less than 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 disposed in the evaporator storage section and in fluid communication with the evaporator of the distillation apparatus. The controller may be configured to determine the total flow command in a second operating state based at least in part on evaporator level data signals indicating the water level in the water column of the evaporator storage section. In some embodiments, the first target temperature may be at least 20°C but not greater than 30°C. In some embodiments, the first target temperature is 25°C.

[0055] According to another embodiment of this disclosure, a method for controlling and distributing the flow of source fluid into a distillation apparatus may include: sensing the level of concentrated material in a concentrated material storage section fluidly connected to the evaporator of the distillation apparatus using a concentrated material level sensor. The method may further include: sensing the temperature of the product fluid produced by the distillation apparatus at a point downstream of a product heat exchanger, wherein the product heat exchanger allows the product fluid to exchange heat with the incoming source fluid. The method may further include: determining a concentrated material accumulation rate based on the concentrated material level using a processor. The method may further include: calculating a first difference between the concentrated material accumulation rate and a first target concentrated material accumulation rate, and a second difference between the concentrated material accumulation rate and a second target concentrated material accumulation rate using a processor. The method may further include: determining a first temporary open state command and a second temporary open state command for a first source inflow proportional valve and a second source inflow proportional valve using a processor. The first temporary open state command may be based on the first difference, and the second temporary open state command may be based on the second difference. The method may further include: calculating a final open state command using a processor based on a temporary open state time command. The method may further include: when the processor is in a first operating state, assigning a final open state command between a first source inflow proportional valve and a second inflow proportional valve. The first source inflow proportional valve may lead to a product heat exchanger. This assignment may be based on the difference between the target product temperature and the temperature of the product fluid. The method may further include: when the processor is in a second operating state, assigning the entire final open state command to the second source inflow proportional valve. The method may further include: when the processor is in the second operating state, opening the first source inflow proportional valve via a command from the processor at a duty cycle not exceeding a predetermined limit.

[0056] In some embodiments, the first target accumulation rate may be greater than the second target accumulation rate. In some embodiments, calculating the final open state command may include inputting a first temporary open state command and a second temporary open state command into the slider. In some embodiments, calculating the final open state command may include generating a mixing command based on the first temporary source open state command and the second temporary source open state command. In some embodiments, calculating the final open state command may include determining a first state fraction and a second state fraction, and multiplying the first temporary open state command by the first state fraction, while multiplying the second temporary open state command by the second state fraction. In some embodiments, calculating the final open state command includes adjusting the command from primarily a first temporary open state command to primarily a second temporary open state command during the transition between the first operating state and the second operating state. In some embodiments, calculating the final open state command may include adjusting the command from a purely first temporary open state command to a purely second temporary open state command during the transition between the first operating state and the second operating state. In some embodiments, the second operating state may be a hot distillate production state. In some embodiments, the allocation may include determining the open state command of the first source inflow proportional valve based on the difference between the target product temperature and the temperature of the product fluid, and determining the open state command of the second source inflow proportional valve by subtracting the open state command of the first source inflow proportional valve from the final open state command. In some embodiments, the predetermined limit may be a limit of less than 5%. In some embodiments, the predetermined limit may be a limit of less than 2%. In some embodiments, the predetermined limit may be 0%. In some embodiments, determining the second temporary open state command may further include: sensing the liquid level of the liquid column in the evaporator storage section, which is in fluid communication with the evaporator, using an evaporator level sensor. The second temporary open state command may be based in part on the difference between the liquid level of the liquid column and a target liquid level of the liquid column. In some embodiments, the second temporary open state command may be based on the rate of change of the difference between the liquid level of the liquid column and the target liquid level of the liquid column.

[0057] According to embodiments of this disclosure, a medical system may include at least one concentrated fluid. The system may further include a distillation apparatus 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 that are in heat exchange relationship with each other. The system may further include a medical device that may include a therapeutic fluid preparation circuit selectively fluidly connected to the purified product water flow path via a point valve. The medical device may include a therapeutic device processor configured to command the at least one concentrated fluid and purified water to mix to generate a prescribed therapeutic fluid through the therapeutic fluid preparation circuit. The system may further include a communication link between the therapeutic device processor of the medical device and the distillation device processor of the distillation apparatus. The medical device processor may be configured to transmit mode commands to the distillation device processor. The system may further include a sensor assembly in communication with the purified product water flow path. The system may further include a source valve between the fluid source and the source fluid flow path. The distillation device processor may be configured to actuate the source valve at least in part based on mode commands and data from the sensor assembly.

[0058] In some embodiments, the sensor assembly may include at least one temperature sensor and at least one conductivity sensor. In some embodiments, the distillation apparatus processor may be configured to actuate the source valve based at least in part on a mode command and temperature data from the sensor assembly. In some embodiments, the distillation apparatus processor may be configured to actuate the source valve based at least in part on a mode command, data from the sensor assembly, and a target setpoint for the 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 apparatus processor based on a mode command. In some embodiments, the target setpoint may be based on a first mode command in the mode commands, which may be in the range of 20° to 35°, and the target setpoint may be based on a second mode command in the mode commands, which may be greater than 90°C.

[0059] In some embodiments, the medical device may be a dialysis machine. In some embodiments, the medical device may be a hemodialysis device. In some embodiments, the therapeutic 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 one liter. In some embodiments, the distillation unit processor may be further configured to control the operation of the compressor motor of the distillation unit at least in part based on mode commands. In some embodiments, the distillation unit processor may be further configured to control the operation of the concentrate outlet valve of the distillation unit at least in part based on mode commands.

[0060] According to embodiments of this disclosure, a medical system may include a distillation apparatus having: an evaporator; a source inlet flow path leading to a source input in fluid communication with the evaporator; a condenser; and a purified product water output flow path in fluid communication with the condenser. The system may further include a first filter and a second filter 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 device including a therapeutic fluid preparation circuit selectively in fluid communication with the purified product water output flow path via a point valve. The system may further include a communication link between a therapeutic device processor of the medical device and a distillation device processor of the distillation apparatus. 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 therapeutic device processor may be configured to perform a second filter replacement check, and, if either the first or second filter replacement check fails, command the distillation device processor to enter a filter replacement mode via the communication link.

[0061] In some embodiments, a second filter replacement check may include a control limit check of the number of days elapsed since the installation of the first and second filters. In some embodiments, the medical device may include a graphical user interface. In some embodiments, a second filter replacement check may include a check of user input on the graphical user interface against at least one predetermined standard. In some embodiments, the system may further include a sampling port disposed between the first and second filters, and the predetermined standard may be a water chemistry test strip standard. In some embodiments, the water chemistry test strip standard may be a chlorination level standard. In some embodiments, a distillation device processor may be configured to command a flushing of the first and second filters prior to at least one of a first filter replacement check or a second filter replacement check. In some embodiments, a distillation device processor may be configured to perform a first filter replacement check based on filter output pressure data signals from a second pressure sensor. In some embodiments, a distillation device processor may be configured to indicate a failure of the first filter replacement check when the filter output pressure is below a threshold. In some embodiments, a distillation device processor may be configured to perform a first filter replacement check based on the difference between the pressure upstream of the first and second filters as indicated by the first pressure sensor and the pressure downstream of the first and second filters as indicated by the second pressure sensor. In some embodiments, a distillation device processor may be configured to indicate a failure of the first filter replacement check when the difference is less than a threshold.

[0062] According to another embodiment of this disclosure, a medical system may include a distillation apparatus having a source water input and a fluid output flow path. The system may further include a medical device comprising a plurality of fluid flow paths, a plurality of valves, at least one fluid pump, and a fluid inlet selectively fluidly connected to the fluid output flow path via a point valve. The system may further include a communication link between the medical device and the distillation apparatus. The system may further include a sensor assembly in communication with the fluid output flow path. The system may further include a treatment device processor configured to actuate the plurality of valves and the at least one fluid pump to pump a high-temperature fluid through the plurality of fluid flow paths. The system may further include a distillation apparatus processor configured to control the operation of the distillation apparatus based on at least one data signal from the sensor assembly and mode commands sent from the treatment device processor of the medical device via the communication link, to generate a high-temperature fluid during a first time period and output the high-temperature fluid to the fluid output flow path, wherein during the first time period the distillation apparatus processor commands the point valve to open, and during the second time period the distillation apparatus processor commands the point valve to close and commands the valve leading to the flow path fluidly connected to the fluid output flow path to open.

[0063] In some embodiments, the source water input may be in fluid communication with a non-temperature-controlled fluid source. In some embodiments, the medical device may be a dialysis machine. In some embodiments, the medical device may be a hemodialysis machine. In some embodiments, the plurality of 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 plurality of fluid flow paths may be included at least in a blood pump cartridge and a dialysate pump cartridge. In some embodiments, the medical device may include a fluid storage unit, and the treatment device processor may be configured to send a signal to the distillation device processor to end a first time period based on the amount of high-temperature fluid contained in the fluid storage unit. In some embodiments, the medical 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 in part 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 the at least one data signal and another mode command sent from the treatment device processor via a communication link to generate a medical fluid component and output the generated medical fluid component to a fluid output flow path. In some embodiments, the plurality of flow paths may include a medical fluid mixing loop, and the treatment device processor may be configured to command the operation of the at least one pump and the plurality of valves to mix a medical fluid component with at least one concentrate in fluid communication with the plurality of flow paths according to a predetermined prescription.

[0064] According to another embodiment of this disclosure, a water distillation apparatus may include a storage tank having a source fluid input. The apparatus may further include an evaporator in fluid communication with the source fluid input via the storage tank. The apparatus may further include a condenser including a condensation section and a condensate accumulation section. The apparatus may further include an auxiliary condensate storage section in fluid communication with the condensate accumulation section and attached to the condenser adjacent to the accumulation surface of the accumulation section. The auxiliary condensate storage section may be fluidly connected to a point-of-use device via a condensate flow path. The apparatus may further include a condensate level sensor configured to monitor the condensate level in the accumulation section and generate a data signal indicating the condensate level in the accumulation section. The apparatus may further include a controller configured to control the operation of a diverter valve included in the condensate flow path based at least in part on the data signal and a target condensate level. The controller may further be configured to command the diverter valve to a closed state based on the derivative of the data signal.

[0065] In some embodiments, the accumulator may have a volume of less than ten liters. In some embodiments, the condensate level sensor may include a float assembly attached to a pivot. The float assembly is capable of displacement about the pivot within a displacement range that includes a point at the same height as the fill level in the accumulator. In some embodiments, the condensate level sensor may include a float capable of displacement along a displacement axis within a displacement range that includes a point at the same height as the fill level in the accumulator. In some embodiments, the condensate level sensor may include a float capable of traversing a displacement path through a displacement range that includes a point at the same height as the fill level in the accumulator. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the derivative of the data signal exceeding a predetermined minimum threshold. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the derivative of the data signal having a negative value greater than a predetermined size. In some embodiments, the controller may be configured to command a diverter valve to a closed state based on a derivative of a data signal, wherein the derivative of the data signal indicates that the point of use is consuming condensate from the distillation apparatus. In some embodiments, the apparatus may further include a heat exchanger comprising a portion of a condensate flow path and a portion of a source flow path coupled to a water source, and a source fluid input. In some embodiments, the apparatus may further include a sensing component in communication with a condensate flow path downstream of a portion of the condensate flow path included in the heat exchanger. The sensing component may be configured to output a temperature data signal. In some embodiments, the controller may be configured to command a diverter valve to a closed state based on a derivative of the temperature data signal. In some embodiments, the controller may be configured to command a diverter valve to a closed state based on a derivative of the temperature data signal exceeding a predetermined maximum threshold. In some embodiments, the controller may be configured to command a diverter valve to a closed state based on a derivative of the temperature data signal having a positive value greater than a predetermined magnitude. In some embodiments, the controller may be configured to command a diverter valve to a closed state based on a derivative of the temperature data signal, wherein the derivative of the temperature data signal indicates that the point of use is consuming condensate from the distillation apparatus. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the integral of the derivative of the temperature data signal. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the integral of the derivative of the temperature data signal exceeding a predetermined maximum threshold. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the integral of the derivative of the temperature data signal having a positive value greater than a predetermined magnitude.In some embodiments, the controller may be configured to command the diverter valve to a closed state based on the integral of the derivative of a temperature data signal, wherein the derivative of the temperature data signal indicates that the point of use is consuming condensate from the distillation unit.

[0066] According to another embodiment of this disclosure, a water distillation apparatus may include a storage tank having a source fluid input. The apparatus may further include an evaporator in fluid communication with the source fluid input via the storage tank. The apparatus may further include a condenser fluidly connected 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 level of the condenser. The apparatus may further include a heat exchanger including a portion of a condensate flow path and a portion of a source flow path connected to a water source, as well as the source fluid input. The apparatus may further include a sensing component in communication with a condensate flow path downstream of a portion of the condensate flow path included in the heat exchanger. The sensing component may be configured to output a sensor component data signal. The apparatus may further include a controller configured to control the operation of a diverter valve included in the condensate flow path based at least in part on the data signal and a target condensate level. The controller may further be configured to command the diverter valve to a closed state based on the derivative of the sensor component data signal.

[0067] In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the derivative of the sensor component data signal. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the derivative of the sensor component data signal exceeding a predetermined maximum threshold. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the derivative of the sensor component data signal having a positive value greater than a predetermined size. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the derivative of the sensor component data signal, wherein the derivative of the sensor component data signal indicates that the point of use is consuming condensate from the distillation equipment. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on an integral calculated using the sensor component data signal. In some embodiments, the integral may be calculated based on the derivative of the sensor component data signal. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the integral exceeding a predetermined maximum threshold. In some embodiments, the controller may be configured to command the shunt valve to a closed state based on the integral having a positive value greater than a predetermined size. In some embodiments, the controller may be configured to command the diverter valve to a closed state based on an integral indicating that the point of use is consuming condensate from the distillation unit. In some embodiments, the sensor component data signal may be a temperature data signal.

[0068] According to another embodiment of this disclosure, a water purification system for outputting a process flow at a controlled temperature may include a distillation apparatus selectively fluidly connected to a fluid source via a set of source proportioning valves. The distillation apparatus may have a concentrate output and a distillate output, respectively coupled to a concentrate stream path and a distillate stream path. The system may further include: a first heat exchanger including a portion of the distillate stream path; and a second heat exchanger including a portion of the concentrate stream path. A flow path from the fluid source may be in heat exchange relationship with each of the first and second heat exchangers. The system may further include a distillate sensor assembly connected to a portion of the distillate stream path downstream of the first heat exchanger, and the distillate sensor assembly is configured to generate a distillate temperature measurement. The system may further include: a controller configured to actuate an input source valve assembly based on a first multi-mode control loop, the first multi-mode control loop generating multiple temporary total open state commands for the source proportional valves; a slider that generates a single total open state command based on the number of temporary commands; and a second control loop that receives distillate temperature measurements, a first target temperature, and a second target temperature, and distributes the single total open state command among all input source valves to adjust the condensate temperature to a temperature setpoint.

[0069] In some embodiments, the system may further include an electronic component box in thermal communication with the source fluid flow path. In some embodiments, the second control loop may allocate a total open state command at least in part by generating a temporary allocation command based at least in part on a first target temperature and a second target temperature and inputting the temporary allocation command into a second slider. In some embodiments, the controller may be configured to operate in multiple operating states, and the temperature setpoint depends on the state. In some embodiments, the controller may be configured to switch between a first state and a second state in the multiple operating states. In some embodiments, at least one of the first multi-mode control loop and the second control loop may include one or more PID control loops. In some embodiments, the one or more PID control loops may include a feedforward term that modifies the output of the one or more PID loops. In some embodiments, the number of temporary total open state commands may be adjusted 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 to generate an output based at least in part on the concentrate temperature. In some embodiments, at least one of the multiple temporary total open state commands may be adjusted by a feedforward term. In some embodiments, at least one of the temporary total on state commands may be changed based on a pre-allocated source duty cycle command, wherein the pre-allocated source duty cycle command is determined at least in part based on a concentrate temperature sensed by a concentrate sensor assembly, wherein the concentrate sensor assembly is in communication with a portion downstream of a concentrate flow path included in the second heat exchanger. In some embodiments, the second control loop may be configured to generate its output in part based on a target electronic component temperature and a current electronic component temperature measured by an electronic component 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.

[0070] According to another embodiment of this disclosure, a water purification system for outputting a process flow at a controlled temperature may include a distillation apparatus selectively fluidly connected to a fluid source via a set of source proportioning valves. The distillation apparatus may have a concentrate output and a distillate output, respectively connected to a concentrate stream path and a distillate stream path. The concentrate output may be located in a concentrate storage section of the distillation apparatus. The system may further include: a first heat exchanger including a portion of the distillate stream path; and a second heat exchanger including a portion of the concentrate stream path; and a flow path from the fluid source that exchanges heat with each of the first and second heat exchangers. The system may further include a distillate sensor assembly connected to a portion of the distillate stream path downstream of the first heat exchanger, and configured to generate a distillate temperature measurement. The system may further include a concentrate level sensor located within the concentrate storage section and configured to output a concentrate data signal. The system may further include a controller configured to determine the total open time of the source proportioning valves based at least in part on a concentrate data signal, a target concentrate rate, and a minimum open time of at least one source proportioning valve. The controller may be configured to allocate a percentage of the total open command to each source proportioning valve based in part on a distillate temperature measurement and the minimum open time.

[0071] In some embodiments, the system may further include at least one source sensor in communication with the source fluid flow path. In some embodiments, the controller may be configured to allocate a percentage of the total open state command to each source proportional valve based in part on source sensor data signals. In some embodiments, the source sensor data signals may be temperature data signals indicating the current source fluid temperature. In some embodiments, the controller may be configured to allocate a percentage of the total open state command to each source proportional valve based on a control loop, wherein the control loop 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 in communication with the concentrate flow path. In some embodiments, the controller may be configured to determine the total open state time of the source proportional valve based at least in part on a concentrate temperature data signal generated by the at least one concentrate temperature sensor. In some embodiments, the controller may be configured to allocate a percentage of the total open state command to each source proportional valve based on a control loop, wherein the control loop 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 command to at least one of the source proportional valve groups. In some embodiments, the controller may be configured to determine the total open state time of the source proportional valve based at least in part on a feedforward term.

[0072] According to another embodiment of this disclosure, a method for calibrating the operating speed setpoint of an impeller compressor disposed in a flow communication path between an evaporator and a condenser in a vapor compression distillation apparatus, the impeller compressor being used to compress low-pressure vapor generated in the evaporator into high-pressure vapor for output to the condenser, the method may include driving impeller rotation to a first speed based on a target low-pressure vapor temperature and a low-pressure vapor temperature measured from a low-pressure vapor temperature sensor. The method may further include performing a binary type search to determine the operating speed setpoint.

[0073] In some embodiments, performing a binary type search may include calculating a speed command based on a target low-pressure steam temperature and a measured low-pressure steam temperature. In some embodiments, performing a binary type search may include calculating the difference between the speed command and the start-up speed and comparing that difference to a range. In some embodiments, performing a binary type search may include narrowing the range and resetting the start-up speed when the difference exceeds the range. In some embodiments, performing a binary type search may include entering a steady state for a period of time before resetting the start-up speed. In some embodiments, performing a binary type search may include comparing the measured low-pressure steam temperature with a target low-pressure steam temperature. In some embodiments, performing a binary type search may include incrementing a timer when the measured low-pressure steam temperature and the target low-pressure steam temperature are within a predetermined range. In some embodiments, performing a binary type search may include saving the current speed command as the operating speed setpoint when the timer has incremented to a predetermined value.

[0074] According to embodiments of this disclosure, a fluid distillation apparatus may include at least one controller and a source inlet selectively fluidly connected to a fluid source via at least one valve. The fluid vapor distillation apparatus may further include an evaporator fluidly connected to the source inlet. The fluid vapor distillation apparatus may further include a vapor chamber coupled to the evaporator and fluidly connected to a compressor. The fluid vapor distillation apparatus may further include a concentrate storage section attached to the vapor chamber via an inflow path. The concentrate storage section may be arranged laterally to the vapor chamber such that at least a portion of the concentrate storage section is at the same height as the vapor chamber. The fluid vapor distillation apparatus may further include a condenser fluidly connected to the compressor outlet via a straight flow path. The straight flow path may include a condenser inlet having an opening section with a plurality of windows. The windows may establish a flow path from the condenser inlet to the condenser. The fluid vapor distillation apparatus may further include a product process flow storage section coupled to the condenser via a product storage section inlet. The product process flow storage section can be arranged laterally relative to the condenser, such that at least a portion of the product process flow storage section is at the same height as the condenser.

[0075] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a plate. The plate may have a section extending into the concentrate storage section at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate storage section and divide the concentrate storage section into a first section and a second shielding section. In some embodiments, the fluid vapor distillation apparatus may further include an exhaust path extending from the concentrate storage section to the vapor chamber. In some embodiments, the exhaust path may be substantially parallel to the inflow path and extend above the inflow path relative to gravity. In some embodiments, the product storage section 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 recessed into the side of the vapor chamber. In some embodiments, the compressor may include an impeller that rotates about an axis that passes through at least a portion of the vapor chamber and is off-center but parallel to the longitudinal axis of the vapor chamber.

[0076] According to another embodiment of this disclosure, a steam distillation apparatus may include a storage tank and an evaporator, a first side of which is in communication with the storage tank. A second side of the evaporator may be in fluid communication with a steam chamber. The steam distillation apparatus may further include a concentrate storage section attached to the steam chamber via an inflow path having a first portion and a second portion. The second portion may be at least partially obstructed. The obstruction may extend into the concentrate storage section in a direction transverse to the first portion and may divide the concentrate storage section into an unobstructed section and an obstructed section. The steam distillation apparatus may further include a float assembly disposed in the obstructed section. The float assembly may be displaced within a displacement range including points of equal height, provided that all steam chamber liquid levels are within a desired steam chamber liquid level range. The steam distillation apparatus may further include a sensor 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. The steam distillation apparatus may further include a compressor having an inlet and an outlet, wherein the inlet is in fluid communication with the steam chamber and the outlet is in fluid communication with a condenser.

[0077] 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 attached to a pivot. In some embodiments, the float assembly may be displaced about a pivot. In some embodiments, the obstruction may extend into the concentrate storage section at an angle substantially perpendicular to a first portion of the inflow path. In some embodiments, the steam distillation apparatus may further include an exhaust path extending from the concentrate storage section to the steam chamber. In some embodiments, the exhaust path may extend parallel to and above the first portion of the inflow path. In some embodiments, the cross-sectional area of ​​the exhaust path may be smaller than the cross-sectional area of ​​the first portion of the inflow path.

[0078] According to another embodiment of this disclosure, a steam distillation apparatus may include a storage tank having a source fluid input. The steam distillation apparatus may further include an evaporator, a first side of which is in fluid communication with the source fluid input via the storage tank, and a second side of which 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 a concentrate as the source fluid travels toward the steam chamber. The steam distillation apparatus may further include a concentrate storage section attached and disposed laterally to the steam chamber. The concentrate storage section may include a concentrate level sensor configured to monitor the level of the concentrate in the steam chamber and generate a data signal indicating the level of the concentrate. The steam distillation apparatus may further include a compressor having: a low-pressure steam inlet in fluid communication with the steam chamber; and a high-pressure steam outlet in 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 outer surfaces of the evaporator. A condenser can be configured to condense a high-pressure vapor stream from a compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of an evaporator. The condenser may include a condensation section and a condensate accumulation or storage section. The steam distillation apparatus may further include an auxiliary condensate storage section in fluid communication with the condensate accumulation section. The auxiliary condensate storage section may be attached to the condenser adjacent to the accumulation surface of the accumulation section. The auxiliary condensate storage section may include a condensate level sensor configured to monitor the condensate level in the accumulation section and generate a data signal indicating the percentage of condensate filling the accumulation section.

[0079] In some embodiments, the accumulation section may have a volume of less than ten liters. In some embodiments, the plurality of outer surfaces may be the outer surfaces of a plurality of evaporator tubes included in an evaporator. In some embodiments, the plurality of outer surfaces may be the outer surfaces of between 90 and 100 evaporator tubes included in an evaporator. In some embodiments, the plurality of outer surfaces may be the outer surfaces of between 70 and 80 evaporator tubes included in an evaporator. In some embodiments, the condensate level sensor may include a float assembly attached to a pivot. In some embodiments, the float assembly may be displaceable about the pivot within a displacement range including a point at the same height as the level range defined by the accumulation section. In some embodiments, the concentrate level sensor may include a float assembly disposed in a shielded section of the concentrate storage section, the shielded section being separated from the unshielded portion of the concentrate storage section by a barrier. In some embodiments, the float assembly may be attached to a pivot, and, provided that all concentrate levels in the vapor chambers are within the expected range of vapor chamber levels, the float assembly may be displaceable about the pivot within a displacement range including a point at the same height. In some embodiments, the concentrate level sensor may be disposed within a sleeve forming a barrier.

[0080] According to another embodiment of this disclosure, a concentrate level control system for a fluid vapor distillation apparatus may include a source fluid input selectively fluidly communicated with a source fluid storage unit via at least one input valve. The concentrate level control system may further include an evaporator fluidly communicated with both the source input and a steam chamber. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the steam chamber. The concentrate level control system may further include a concentrate storage unit laterally attached to and disposed within the steam chamber via an inflow path, and including an outlet selectively communicated 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 level of concentrate in the steam chamber. The concentrate level control system may also include a controller configured to intentionally change the concentrate level in a predetermined pattern by controlling actuation of at least one inlet valve via a fluid input control loop and analyzing the data signal. The controller can be further configured such that when a data signal indicates that the concentrate level is below a first threshold, the controller actuates the outlet valve to a closed state, and when the concentrate level is above a second threshold, the controller actuates the outlet valve to an open state.

[0081] In some embodiments, a predetermined pattern can generate a sawtooth waveform when the concentrate level is plotted over time. In some embodiments, the period of the sawtooth waveform can be at least partially dependent on a fluid input command from a fluid input control loop. In some embodiments, the fluid input command can be determined based on a predetermined target concentrate production rate. In some embodiments, the controller can be configured to operate in multiple operating states, and the predetermined target concentrate production rate can be state-specific. In some embodiments, the controller can analyze data signals on a predetermined basis. In some embodiments, a predetermined expected range can be assigned to the concentrate level, and a first threshold can be less than or equal to 50% of the maximum level of the expected range. In some embodiments, the first threshold can be between 40% and 50% of the maximum level of the expected range. In some embodiments, a predetermined expected range can be assigned to the concentrate level, and a second threshold can be greater than or equal to 50% of the maximum level of the expected range. In some embodiments, the second threshold can be between 50% and 60% of the maximum level of the expected range. In some embodiments, a predetermined expected range can be assigned to the concentrate level, and a first threshold can be less than or equal to 40% of the maximum level of the expected range. In some embodiments, the first threshold can be between 40% and 30% of the maximum level of the expected range. In some embodiments, a predetermined expected range may be assigned to the concentrate level, and a second threshold may be greater than or equal to 45% of the maximum level within the expected range. In some embodiments, the second threshold may be between 45% and 55% of the maximum level within the expected range. In some embodiments, a predetermined expected range may be assigned to the concentrate level, and the first and second thresholds may be defined as percentages of the maximum level within the expected range. The second threshold may be 4 to 20 percentage points larger than the first threshold. In some embodiments, the concentrate is destined for a mixing tank.

[0082] According to another embodiment of this disclosure, a method for controlling the level of concentrate in a distillation apparatus and verifying fluid flow within the distillation apparatus may include: inputting source fluid into the distillation apparatus through at least one inlet valve. The method may further include: evaporating at least a portion of the source fluid to generate steam and concentrate as it travels toward a steam chamber. The method may further include: collecting the concentrate in a concentrate storage section, wherein the concentrate storage section is attached and disposed transversely to the steam chamber via an inflow path. The method may further include: providing a data signal indicating the level of concentrate in the steam chamber from a concentrate level sensor disposed in the concentrate storage section. The method may further include: using a controller to change the concentrate level in a predetermined pattern by controlling the actuation of at least one inlet valve and analyzing the data signal via a fluid input control loop, and actuating the outlet valve of the concentrate storage section to a closed state when the data signal indicates that the concentrate level is below a first threshold, and actuating the outlet valve of the concentrate storage section to an open state when the concentrate level is above a second threshold.

[0083] In some embodiments, changing the concentrate level may include: changing the concentrate level to produce a sawtooth waveform when plotting the concentrate level 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 predetermined expected range to the concentrate level and setting a first threshold to be 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 between 40% and 50% of the maximum level of the expected range. In some embodiments, the method may further include: assigning a predetermined expected range to the concentrate level and setting a second threshold to be greater than or equal to 50% of the maximum level of the expected range. In some embodiments, setting the second threshold includes setting the second threshold between 50% and 60% of the maximum level of the expected range. In some embodiments, the method may further include: assigning a predetermined expected range to the concentrate level and setting a first threshold to be 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 between 40% and 30% of the maximum level of the expected range. In some embodiments, the method may further include: assigning a predetermined expected range to the concentrate level and setting a second threshold to be greater than or equal to 45% of the maximum level of the expected range. In some embodiments, setting the second threshold includes setting the second threshold between 45% and 55% of the maximum material level within a desired range. In some embodiments, the method may further include: allocating a predetermined desired range of concentrated material levels, and setting the first threshold and the second threshold as percentages of the maximum material level within the desired range, wherein the second threshold is 4 to 20 percentage points larger than the first threshold.

[0084] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation apparatus to a desired temperature may include a source fluid input selectively fluidly communicated with a source fluid storage unit via a set of fluid input valves. The system may further include an evaporator fluidly communicated with both the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The system may further include a condenser fluidly communicated with the compressor and configured to convert pressurized vapor from the compressor into condensate. The system may further include a condensate stream path and a concentrate stream path, each including a corresponding first heat exchanger and a second heat exchanger. The first and second heat exchangers may each include a heat exchange section from the source fluid stream path of the source fluid storage unit. The heat exchange section may be 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 in the condensate stream path downstream of the first heat exchanger. The system may further include a controller configured to actuate an input source valve group based on a first control loop and a second control loop, and to allocate a total open state time among all input source valves to regulate the condensate temperature to a desired temperature, wherein the first control loop controls the total open state time of all input source valves in the input source valve group, and the second control loop receives a data signal and the desired temperature.

[0085] In some embodiments, the heat exchange sections of the source fluid flow paths within the first and second heat exchangers may be configured to flow countercurrently to their respective condensate and concentrate flow paths. In some embodiments, the system may further include a destination device that is in fluid communication with the condensate flow path via a point-of-use valve. In some embodiments, the requested 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 PID control loops 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 allocated based on an estimated total on-state 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 within the distillation apparatus. The first control loop may be configured to receive a target concentrate level and a current concentrate level data signal as inputs to the first control loop. In some embodiments, the controller may be further configured to adjust the heater duty cycle based at least in part on the total open time of all input source valves in the input source valve group. In some embodiments, the controller may be configured to increase the heater duty cycle as the open time of all input source valves in the input source valve group increases.

[0086] According to another embodiment of this disclosure, a method for controlling the temperature of a product process flow in a distillation apparatus to a requested temperature may include: controlling the flow rate of a source fluid input to the distillation apparatus by actuating a set of source fluid valves using a controller. 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 apparatus through corresponding condensate and concentrate streams. The method may further include: exchanging heat between the source fluid flow and the condensate stream in a first heat exchanger, and exchanging heat between the source fluid flow and the concentrate stream in a second heat exchanger. The method may further include: providing a condensate temperature data signal to the controller from a temperature sensor located downstream of the first heat exchanger in the condensate stream. The method may further include: determining the total open state time of fluid input valve groups among fluid input valve groups based on a first control loop; and allocating the total open state time among fluid input valve groups based on a second control loop, wherein the second control loop receives the temperature data signal and the requested temperature.

[0087] In some embodiments, the method may further include: flowing condensate and concentrate in a direction countercurrent to the flow of the source fluid through a condensate path and a concentrate path. In some embodiments, the method may further include: supplying condensate to a destination device via an actuated point-of-use valve downstream of a temperature sensor. In some embodiments, the requested 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: using the condensate to mix dialysate. 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 a first control loop and a second control loop 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 a second control loop. In some embodiments, the method may further include: determining the feedforward term based on an estimated allocation of the total open state time. In some embodiments, the method may further include: inputting the current concentrate level and the target concentrate level provided by a concentrate level sensor to the first control loop. In some embodiments, the method may further include: adjusting the heater duty cycle based at least in part on the total open state time of all input source valves in the input source valve group. In some embodiments, adjusting the heater duty cycle may include increasing the heater duty cycle when the open state time of all input source valves in the input source valve group is increased.

[0088] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation apparatus to a desired temperature may include a first source fluid input and a second fluid source input, the first and second source fluid inputs being selectively fluidly communicated with a source fluid storage unit via a first set of fluid input valves and a second set of fluid input valves, respectively. The system may further include an evaporator fluidly communicated with the first and second source fluid inputs and with a compressor. The evaporator may have a heating element to convert the source fluid from the first and second source fluid inputs into a vapor stream and a condensate stream as the source fluid travels toward the compressor. The system may further include a condenser fluidly communicated with the compressor. The condenser may be configured to convert pressurized vapor from the compressor into condensate. The system may further include a condensate stream path and a condensate stream path, the condensate stream path and the condensate stream path including respective first and second heat exchangers. The first and second heat exchangers may each include a heat exchange section of the source fluid stream path from the source fluid storage unit downstream of the source fluid input valve assembly. 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 in the condensate flow path downstream of the first heat exchanger. The system may also include a controller configured to actuate a first set of input source valves based on a first control loop and a second control loop, and to allocate a total open time among all input source valves in the first set of input source valves to regulate the condensate temperature to a desired temperature, wherein the first control loop controls the total open time of all input source valves in the first set of input source valves, and the second control loop receives the data signal and the desired temperature. The controller may be configured to monitor at least one process variable and actuate a second set of input source valves when one of the at least one process variable is outside a predetermined threshold.

[0089] 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 source fluid input and the second source fluid input 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 hot fluid input. In some embodiments, at least one process variable monitored by the controller may be the heating element duty cycle. In some embodiments, the at least one process variable monitored by the controller may be the output of a first control loop. In some embodiments, the at least one process variable may be the compressor speed. In some embodiments, the heat exchange section of the source fluid flow path may be a common flow path for fluids from the first source fluid input and the second source fluid input.

[0090] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation apparatus to a desired temperature may include a source fluid input selectively fluidly communicated with a source fluid reservoir via a set of fluid input valves. The system may further include an evaporator selectively fluidly communicated with the source fluid input via a bypass valve and fluidly communicated with a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The system may further include a condenser fluidly communicated with the compressor and configured to convert pressurized vapor from the compressor into condensate. The system may further include a condensate stream path and a concentrate stream path, each including a corresponding first heat exchanger and a second heat exchanger. The first and second heat exchangers may each include a heat exchange section of the source fluid stream path from the source fluid reservoir 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 in the condensate stream path downstream of the first heat exchanger. The system may further include a controller configured to actuate the input source valve group based on a first control loop and a second control loop, and to allocate a total open state time among all input source valves to regulate the condensate temperature to a desired temperature. The first control loop controls the total open state time of all input source valves in the input source valve group, and the second control loop receives a data signal and the desired temperature. A bypass valve may be located in the source fluid flow path upstream of the heat exchange section of the source fluid flow path. The bypass valve may have a diversion valve state that directs fluid from the source storage section to the discharge destination. The controller may be configured to actuate the bypass valve to the diversion valve state when it determines that 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, the at least one process variable may be the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, the at least one process variable may be defined at least in part by the condensate temperature and the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, when the bypass valve is in a diverter state, the controller may change the duty cycle of at least one of the input source valves. In some embodiments, when the bypass valve is in a diverter state, the controller may increase the duty cycle of at least one of the input source valves. In some embodiments, when the bypass valve is in a diverter state, the controller may change the duty cycle of at least one input source valve to 90% to 100%. In some embodiments, one of the at least one input source valve may be a valve that controls the flow rate of the source fluid through the heat exchange section of a first heat exchanger.

[0092] According to another embodiment of this disclosure, a temperature control system for controlling the temperature of the product process stream of a distillation system to a desired temperature may include a source fluid input selectively fluidly communicated with a source fluid storage unit via a set of fluid input valves. The system may further include a distillation apparatus configured to generate a concentrated stream and a condensate stream. The system may further include a condensate stream path and a concentrated stream path, each including a corresponding first heat exchanger and a second heat exchanger. The first and second heat exchangers may each include a heat exchange section from the source fluid flow path of the source fluid storage unit, 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 stream path downstream of the first heat exchanger. The system may further include a point-of-use device selectively communicated with the condensate stream path. The point-of-use device may have an outlet fluid path for discharging the fluid generated by the point-of-use device. The outlet fluid path may have a third heat exchanger including a heat exchange section of a branch of the source fluid flow path. The system may further include a controller configured to actuate an input source valve assembly based on a first control loop and a second control loop and based on at least one process variable, wherein the first control loop and the second control loop control the flow of source fluid through the heat exchange sections of the first and second heat exchangers. When the at least one process variable is outside a predetermined threshold, the controller may actuate a branch valve to a branch of the source fluid flow path.

[0093] 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, the at least one process variable may be the source fluid temperature sensed by the source fluid temperature sensor. In some embodiments, the at least one process variable may be defined at least in part by the condensate temperature and the source fluid temperature sensed by the 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, a branch of the source fluid flow path may be located upstream of the heat exchange section of the source fluid flow path in the first heat exchanger and the second heat exchanger. In some embodiments, the output fluid may be dialysate effluent.

[0094] According to another embodiment of this disclosure, a condensate accumulation rate control system for controlling the condensate accumulation rate within a distillation apparatus may include a source fluid input selectively fluidly communicated with a source fluid storage section via a set of fluid input valves. The system may further include an evaporator fluidly communicated with the source input and with a compressor having an impeller operatively coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a condensate stream as the source fluid travels toward the compressor. The system may further include a condenser in heat transfer relationship with a plurality of outer surfaces of the evaporator. The condenser may be configured to condense a high-pressure vapor stream from the compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The system may further include a condensate level sensor configured to sense the current condensate level in the condenser. The system may further include at least one controller configured to control the impeller rotational speed by periodically generating impeller motor commands based on a last motor speed command, a motor speed target, and speed command increment limits. The target motor speed can be calculated using a control loop that receives the current condensate level and the desired condensate level as inputs.

[0095] In some embodiments, the speed command increment limit may be ≤10 rpm / sec (revolutions per minute per second). In some embodiments, the speed command increment limit may be ≤5 rpm / sec. In some embodiments, the controller may be configured to compare the impeller motor command with a minimum command speed threshold and a maximum command speed threshold, and when the impeller motor command is less than the minimum command speed threshold, the controller adjusts the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold, and when the impeller motor command is greater than the maximum command speed threshold, the controller adjusts the impeller motor command to a modified impeller motor command equal to the maximum command speed threshold. In some embodiments, the minimum command speed threshold is between 1500 rpm and 2500 rpm. In some embodiments, the maximum command speed threshold is calculated whenever 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, wherein 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 may be limited to a predetermined value. In some embodiments, the predetermined value may be between 4500 rpm and 6500 rpm. In some embodiments, the predetermined value may be 5000 rpm. In some embodiments, the predetermined value may be approximately 2.5 times larger than the minimum command speed threshold.

[0096] According to another embodiment of this disclosure, a method for controlling the condensate accumulation rate within a distillation apparatus may include providing a source fluid input to the distillation apparatus. The method may further include: evaporating at least a portion of the source fluid input to low-pressure steam in an evaporator. The method may further include: compressing the low-pressure steam into 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 the evaporator. The method may further include providing a condensate level within the condenser, sensed by a condensate level sensor, to a controller. 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 impeller rotational speed by periodically generating impeller motor commands based on a last motor speed command, the motor speed target, and speed command increment limits.

[0097] 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 when the impeller motor command is less than the minimum command speed threshold, adjusting the impeller motor command to a modified impeller motor command equal to the minimum command speed threshold, and when the impeller motor command is greater than the maximum command speed threshold, adjusting the impeller motor command to a modified impeller motor command equal to the maximum command speed threshold. In some embodiments, the minimum command speed threshold may be between 1500 rpm and 2500 rpm. In some embodiments, the minimum command speed threshold may be 2000 rpm. In some embodiments, the method may further include: calculating a maximum command speed threshold whenever 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 a temperature data signal indicating the motor temperature to the controller from a motor temperature sensor, and providing a power factor correction data signal indicating the current power factor correction current to the controller from a monitoring circuit. In some embodiments, the method may further include: calculating a maximum command speed threshold based on temperature data signals and power factor correction data signals. In some embodiments, the method may further include: setting an upper limit of the maximum command speed threshold to a predetermined value. In some embodiments, the predetermined value may be between 4500 rpm and 6500 rpm. In some embodiments, the predetermined value may be 5000 rpm. In some embodiments, the predetermined value may be a minimum command speed threshold or may be approximately 2.5 times larger than the minimum command speed threshold.

[0098] According to embodiments of this disclosure, a fluid vapor distillation apparatus having a first separable section and a second separable section may include a source inlet selectively fluidly connected to 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 in fluid communication with the reservoir. The apparatus may further include a steam chamber coupled to the evaporator and in fluid communication with a compressor. The apparatus may further include a condenser in fluid communication with the compressor outlet. The condenser may surround the plurality of tubes. The apparatus may further include a support plate 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 member. In a first state, the first and second sections may be held together by one or more fasteners, while in a second state, the first and second sections are separated from each other, in which the first section is rotatable about a pivot.

[0099] In some embodiments, the at least one mounting member may be an isolation mounting member. In some embodiments, the first section may include a storage tank, 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 the relaxed state and a second position when the biasing member is in the 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.

[0100] According to another embodiment of this disclosure, the distillation apparatus may include a source fluid input selectively fluidly communicated with a source fluid storage unit via a set of fluid input valves. The apparatus may further include an evaporator fluidly communicated with both the source input and a compressor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The apparatus may further include a condenser fluidly communicated with the compressor and configured to convert pressurized vapor from the compressor into condensate. The apparatus may further include a condensate stream path and a concentrate stream path, each including a corresponding first and second heat exchanger. The first and second heat exchangers may each include a heat exchange section from the source fluid stream path of the source fluid storage unit. The heat exchange section may be downstream of the source fluid input valve. 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 in the condensate stream path downstream of the first heat exchanger. The apparatus may further include an output leading to a destination device. The device may further include a controller configured to actuate the input source valve group based on a first multi-mode control loop, wherein the first multi-mode control loop generates multiple temporary overall open state commands for all input source valves in the input source valve group. The controller may be configured to actuate the input source valve group based on a slider, wherein the slider generates a single overall open state command from multiple temporary commands. The controller may be configured to actuate the input source valve group based on a second control loop, which receives a data signal and a requested temperature, and distributes the overall open state command among all input source valves to regulate the condensate temperature to a temperature setpoint.

[0101] In some embodiments, the heat exchange sections of the source fluid flow paths within the first and second heat exchangers may be configured to flow counter-currently 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 depend on the state. In some embodiments, the apparatus further includes a destination device that is in fluid communication 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 multi-mode control loop and the second control loop may include a PID control loop. In some embodiments, the gain of at least one of the PID control loops may be zero. In some embodiments, the number of temporary total open state commands may be adjusted by the output of at least one regulator control loop. In some embodiments, the distillation apparatus may further include a reservoir. The reservoir may be located between the source input and the evaporator. One of the at least one regulator control loops may be configured to generate an output based on a target reservoir temperature and a current reservoir temperature measured by a reservoir temperature sensor, wherein the reservoir temperature sensor 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 regulator control loop may be configured to generate an output based on a target steam temperature and a current steam temperature measured by a steam temperature sensor, wherein the steam temperature sensor is configured to generate a data signal representing the temperature of the steam flow. In some embodiments, the apparatus may further include a concentrate level sensor configured to output a concentrate level data signal indicating the concentrate level within the distillation unit. The controller may be configured to determine the current blowdown rate from the concentrate level data signal. A first multi-mode control loop may be configured to receive the target blowdown rate and the current blowdown rate data signals as inputs. In some embodiments, at least one of the temporary total open state commands may be a first production temperature state command, and at least one of the temporary total open state commands may be a second production temperature state command. In some embodiments, the apparatus may further include an evaporator level sensor configured to output an evaporator data signal. The controller may be configured to generate at least one of the temporary total open state commands based at least in part on the input 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 derivative controller. In some embodiments, the derivative controller may be a PID controller in which the gain of the D term is at least an order of magnitude greater than that of the P and I terms.

[0102] According to another embodiment of this disclosure, a steam distillation apparatus may include a reservoir with a source fluid input. The apparatus may further include an evaporator, a first side of which is in fluid communication with the source fluid input via the reservoir, and a second side of which 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 travels toward the steam chamber. During operation, the liquid level in the evaporator may be uneven. The apparatus may further include an evaporator storage section disposed transversely to the evaporator and in fluid communication with the evaporator via the reservoir. The evaporator storage section may include a level sensor configured to monitor the water level in the water column of the evaporator storage section and generate a data signal indicating the water level. The apparatus may further include a compressor having a low-pressure steam inlet and a high-pressure steam outlet, wherein the low-pressure steam inlet is in fluid communication with the steam chamber, and the high-pressure steam outlet is in fluid communication with the condenser via a condenser inlet. The apparatus may further include a condenser that is in heat transfer relationship with a plurality of outer surfaces of the evaporator. The condenser can be configured to condense a high-pressure vapor stream from a compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The condenser may include a condensation section and a condensate accumulation section. The device may further include a processor configured to actuate a set of input source valves to the source fluid input, partially based on data signals.

[0103] In some embodiments, the level sensor may include a movable member capable of displacement within a displacement range less than the height of the evaporator storage section. In some embodiments, the level sensor may include a movable member capable of displacement within a displacement range extending from a first end of the evaporator storage section to at least the midpoint of the evaporator storage section. The displacement range may be a distance less than 70% of the height of the evaporator storage section. In some embodiments, the first end may be the end of the evaporator storage section furthest from the storage tank. In some embodiments, the evaporator storage section may communicate with the steam chamber via an exhaust path extending from the first end of the evaporator storage section. In some embodiments, the exhaust path may extend from the evaporator storage section to a concentrate storage section, which is attached and disposed laterally to the steam chamber. In some embodiments, the height of the evaporator storage section may be greater than the height of the evaporator. In some embodiments, the processor may be configured to determine the total open state time of the input source valve group in part based on a target water column level determined via analysis of data signals and the current water column level. In some embodiments, the processor may be configured to determine the total open state time of the input source valve group in part based on the output of a PID controller, wherein the PID controller receives the target water column level and the current water column level as inputs. In some embodiments, the gain of at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain of the D term of the PID controller may be at least an order of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, the gain of the D term of the PID controller may be two orders of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, the processor may be configured to determine the total open state time in part based on a target discharge rate and a current discharge rate, indicated by a discharge level data signal generated by a discharge level sensor attached to the discharge storage section of the steam chamber. In some embodiments, the processor may be configured to determine the total open state command in part based on the output of at least one regulator control loop. In some embodiments, one of the at least one regulator control loop may be configured to generate an output based on a target tank temperature and a current tank temperature measured by a tank temperature sensor configured to generate a data signal representing the temperature of the fluid in the tank. In some embodiments, one of the at least one regulator control loop may be configured to generate an output based on a target steam temperature and a current steam temperature measured by a steam temperature sensor configured to generate a data signal representing the steam flow temperature. In some embodiments, the controller may be configured to change the overall open state command of the input source valve group in response to a change in the water column level indicated by the data signal. In some embodiments, the controller may be configured to change the overall open state command of the input source valve group proportionally to the rate of change of the water column indicated by the data signal.

[0104] According to another embodiment of this disclosure, a method for controlling the flow rate of a source fluid into a distillation apparatus may include: establishing a non-uniform liquid level in the evaporator of the distillation apparatus by boiling the liquid in the distillation apparatus. The method may further include: sensing the liquid column level in an evaporator storage section using a first level sensor, wherein the evaporator storage section is in fluid communication with the evaporator and is positioned at the same height as the evaporator. The method may further include: sensing the level of concentrated material in a concentrate storage section in fluid communication with the evaporator using a second level sensor. The method may further include: generating a source inlet valve opening time command using a processor, based at least in part on the concentrated material level, a target concentrate accumulation rate, and the difference between the liquid column level and the target liquid column level. The method may further include: commanding multiple source inlet valves to open based on the source inlet valve opening time command.

[0105] In some embodiments, sensing the liquid column level may include displacing a movable member within a displacement range less than the height of the evaporator reservoir. In some embodiments, sensing the liquid column level may include displacing the movable member within a displacement range extending from a first end of the evaporator reservoir to at least the midpoint of the evaporator reservoir. The displacement range may be a distance less than 70% of the height of the evaporator reservoir. In some embodiments, the first end may be the end of the evaporator reservoir furthest from the distillation apparatus. In some embodiments, the method may further include venting the evaporator reservoir to a vapor chamber of the distillation apparatus disposed above the evaporator via a venting path. In some embodiments, the venting path may extend from the evaporator reservoir to a concentrate reservoir, which is attached and disposed laterally to the vapor chamber. In some embodiments, generating a source inlet valve opening time command may include inputting a difference to a PID controller. In some embodiments, the gain of at least one of the P, I, and D terms of the PID controller may be zero. In some embodiments, the gain of the D term of the PID controller may be at least an order of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, the gain of the D term of the PID controller may be two orders of magnitude greater than the gains of the P and I terms of the PID controller. In some embodiments, generating a source inlet valve opening time command may include determining the current concentrate accumulation rate based on the concentrate level and calculating the difference between the target concentrate rate and the current concentrate accumulation rate. In some embodiments, generating a source inlet valve opening time command may include generating the output of at least one regulator control loop. In some embodiments, the method may further include: sensing the current tank temperature using a tank temperature sensor, and generating the output of at least one regulator control loop includes generating the output based on the target tank temperature and the current tank temperature. In some embodiments, the method may further include: sensing the temperature of the vapor flow in the distillation apparatus using a vapor temperature sensor. In some embodiments, generating the output of at least one regulator controller may include generating the output based on the target vapor temperature and the current vapor temperature. In some embodiments, the method may further include: changing the source inlet valve opening time command in response to a change in the liquid column level. In some embodiments, the method may further include: changing the source inlet valve opening time command proportionally to the rate of change of the liquid column level.

[0106] According to another embodiment of this disclosure, a fluid vapor distillation apparatus may include at least one controller. The apparatus may further include a source inlet selectively fluidly connected to a fluid source via at least one valve. The apparatus may further include an evaporator fluidly connected to the source inlet. The apparatus may further include a steam chamber coupled to the evaporator and fluidly connected to a compressor. The outer surface of the steam chamber may form part of an inlet flow path to the compressor and part of an outlet flow path to the compressor outlet. The apparatus may further include a concentrate storage section. The concentrate storage section may be attached to the steam chamber via an inflow path and disposed transversely to the steam chamber, such that at least a portion of the concentrate storage section is at the same height as the steam chamber. The apparatus may further include a condenser fluidly connected to the compressor outlet via a straight flow path. The straight flow path may include a condenser inlet fixedly attached to a sheet having a first side defining a portion of the steam chamber and an opposite side defining a portion of the condenser. The device may further include a product process flow storage section connected to the condenser via a product storage section inlet and disposed transversely to the condenser, such that at least a portion of the product process flow storage section is at the same height as the condenser.

[0107] In some embodiments, the inflow path may include an obstruction. In some embodiments, the obstruction may include a wall extending into the concentrate storage section at an angle substantially perpendicular to the inflow path. In some embodiments, the obstruction may extend into the concentrate storage section and divide the concentrate storage section into a first section and a second shielding section. In some embodiments, the obstruction may include at least one vent. In some embodiments, the product storage section inlet may be adjacent to the product accumulation surface of the condenser. In some embodiments, the compressor may be driven by a motor partially disposed within a receiving well recessed into the side of the steam chamber. In some embodiments, the compressor may include an impeller that rotates about an axis extending laterally relative to the steam chamber and parallel to the longitudinal axis of the steam chamber.

[0108] According to another embodiment of this disclosure, the distillation apparatus may include a source fluid input selectively fluidly communicated with a source via a set of fluid inlet valves. The apparatus may further include an evaporator fluidly communicated with the source input and with a compressor having an impeller operatively coupled to an impeller motor. The evaporator may be configured to convert the source fluid from the source fluid input into a vapor stream and a concentrate stream as the source fluid travels toward the compressor. The apparatus may further include a condenser in heat transfer relationship with a plurality of outer surfaces of the evaporator. The condenser may be configured to condense the high-pressure vapor stream from the compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The apparatus may further include a concentrate level sensor configured to sense the current concentrate level in a concentrate storage section having an inflow path disposed above the evaporator and having a long axis extending side-by-side along the evaporator. The device may further include at least one controller configured to periodically generate impeller motor commands based on a rated speed command for low-temperature distillate production in a low-temperature distillate production state and a rated speed command for high-temperature distillate production in a high-temperature distillate production state, thereby controlling the impeller speed in both the low-temperature and high-temperature distillate production states. The rated speed command for low-temperature distillate production may be a motor speed command that is faster than the rated speed command for high-temperature distillate production.

[0109] In some embodiments, the impeller motor command can be adjusted based on a data signal from a concentrate level sensor, wherein the data signal indicates the level of concentrate in the concentrate storage compartment. In some embodiments, the adjustment can be limited by an impeller motor command increment limit. In some embodiments, the impeller motor command increment limit can be ≤10 rpm / sec. In some embodiments, the impeller motor command increment limit can be ≤5 rpm / sec. In some embodiments, the impeller motor command can be decreased when the data signal indicates that the level of concentrate in the concentrate storage compartment is greater than a first threshold. In some embodiments, the first threshold can be defined as the concentrate level at which the concentrate storage compartment is between 65% and 80% of its full capacity. In some embodiments, when the data signal indicates that the level of concentrate in the concentrate storage compartment is greater than the first threshold, the impeller motor command can be maintained at a value no greater than the previous command. In some embodiments, the first threshold can be defined as the concentrate level at which the concentrate storage compartment is between 65% and 80% of its full capacity. In some embodiments, the impeller motor command can be increased when the data signal indicates that the level of concentrate in the concentrate storage compartment is greater than a second threshold. In some embodiments, the rated production rate command for high-temperature distillate may be a calibrated value defined during manufacturing. In some embodiments, the rated production rate command for high-temperature distillate may be less than 80% and greater than 70% of the rated production rate command for low-temperature distillate. In some embodiments, the rated production rate command for low-temperature distillate may be 4500 rpm.

[0110] According to another embodiment of this disclosure, a method for controlling a compressor in a distillation apparatus may include: opening at least one fluid inlet valve to deliver a source fluid from a fluid source to a storage tank in the distillation apparatus. The method may further include: converting the source fluid into a concentrated stream and a vapor stream in an 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 rated speed command for low-temperature distillate production in a low-temperature distillate production state, and may be based on a rated speed command for high-temperature distillate production in a high-temperature distillate production state. The rated speed command for low-temperature distillate production may be a motor speed command that is faster than the rated speed command for high-temperature distillate production. 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 compressor impeller to rotate at the final command speed. The method may further include: compressing the vapor stream via the compressor. The method may further include: condensing the vapor stream into condensate, and transferring heat to the evaporator as the vapor stream condenses.

[0111] In some embodiments, the method may further include: sensing the level of concentrated material in a concentrate storage compartment fluidly in 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 concentrated material level. In some embodiments, determining the adjustment may include reducing the compressor speed command when the concentrated material level is greater than a first threshold. In some embodiments, the first threshold may be defined as the concentrated material level at which the concentrate storage compartment is between 65% and 80% of its full capacity. In some embodiments, determining the adjustment may include: maintaining the final command speed at a final command speed no greater than a previously commanded final command speed when the concentrated material level is greater than the first threshold. In some embodiments, determining the adjustment may include: reducing the compressor speed command when the concentrated material level is greater than 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 incremental limit. In some embodiments, the incremental limit may be ≤10 rpm / sec. In some embodiments, the incremental limit may be ≤5 rpm / sec. In some embodiments, the high-temperature distillate production rated speed command may be a calibration value defined during manufacturing. In some embodiments, the rated production rate command for high-temperature distillate can be less than 80% and greater than 70% of the rated production rate command for low-temperature distillate. In some embodiments, the rated production rate command for low-temperature distillate can be 4500 rpm.

[0112] According to another embodiment of this disclosure, the distillation apparatus may include a reservoir selectively fluidly connected to a source via a set of fluid inlet valves. The apparatus may further include at least one heating element and at least one reservoir temperature sensor in the reservoir. 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 fluidly connected to the reservoir and a second side fluidly connected to a compressor, wherein the compressor has an impeller operatively coupled to an impeller motor. The evaporator may be configured to convert the source fluid from a source fluid inlet into a vapor stream and concentrate as the source fluid travels toward a vapor chamber. The apparatus may further include a condenser in thermal transfer relationship with a plurality of outer surfaces of the evaporator. The condenser may be configured to condense a high-pressure vapor stream from the compressor by contacting the high-pressure vapor stream with the plurality of outer surfaces of the evaporator. The apparatus may further include a concentrate level sensor configured to sense the current concentrate level in a concentrate storage section, wherein the concentrate storage section has an inflow path disposed above the evaporator and has a long axis extending side-by-side along the evaporator. The device may further include a steam temperature sensor disposed 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 based at least in part on the target temperature of the steam flow, the steam temperature data signal, the tank temperature data signal, and a total source opening command for the fluid input valve assembly.

[0113] In some embodiments, the target temperature of the steam stream may be 108°C. In some embodiments, the controller may be configured to adjust the duty cycle command to meet 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 based at least in part on the power consumption of the compressor. In some embodiments, the controller may be configured to calculate the limit of the duty cycle command by determining the power consumption of the compressor and subtracting the power consumption of the compressor from a predetermined power value. In some embodiments, the predetermined power value may be defined as the maximum total power of the system. In some embodiments, the duty cycle command may be limited to a predetermined maximum duty cycle. In some embodiments, the predetermined maximum duty cycle may be no greater than 90% of the duty cycle. In some embodiments, the target temperature of the steam stream may be state-specific. In some embodiments, the target temperature in a low-temperature distillate production state may be greater than the target temperature in a high-temperature distillate production state. In some embodiments, the target temperature of the steam stream in a first state may be 108°C, and the target temperature of the steam stream in a 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 for determining the duty cycle command based on the total source open command of the fluid input valve assembly and at least one thermodynamic property of the source fluid. In some embodiments, the thermodynamic property may be the specific heat of the source fluid. In some embodiments, the target temperature of the vapor flow may be 111°C to 112°C.

[0114] According to embodiments of this disclosure, a method for heating a fluid in a distillation apparatus may include opening at least one fluid inlet valve to deliver source fluid from a fluid source to a reservoir in the distillation apparatus. 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 steam temperature of a vapor stream generated from the source fluid. The method may further include: comparing the steam temperature with a target steam temperature using a processor. The method may further include: inputting the difference between the steam temperature and the target steam temperature to a first controller and generating a first controller output. The method may further include: providing input to a second controller based at least in part on the first controller output and the reservoir temperature, and generating a second controller output. The method may further include: changing the second controller output to a modified second controller output based on the total open state time of the at least one fluid inlet valve. The method may further include: commanding the duty cycle of a heating element in the reservoir based on the modified second controller output and at least one limit.

[0115] In some embodiments, the target steam 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, the at least one limit may include a limit based at least in part on the power consumption of the compressor in the distillation apparatus. In some embodiments, the method may further include calculating one of the at least one limits by determining the power consumption of the compressor and subtracting the power consumption of the compressor from a predetermined power value. In some embodiments, the predetermined power value may be defined as the maximum total power of the system. In some embodiments, the at least one limit may include a predetermined maximum duty cycle limit. In some embodiments, the predetermined maximum duty cycle may be no greater than a 90% duty cycle. In some embodiments, the target steam temperature of the steam stream may be state-specific. In some embodiments, the target temperature in a low-temperature distillate production state may be greater than the target temperature in a high-temperature distillate production state. In some embodiments, the target temperature in a first state may be 4°C higher than the target temperature in a 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 the total source opening command of the at least one fluid input valve and at least one thermodynamic property of the source fluid. In some embodiments, the thermodynamic property may be the specific heat of the source fluid.

[0116] According to embodiments of this disclosure, a water distillation apparatus may include a storage tank selectively fluidly connected to a fluid source via a set of source proportioning valves. The apparatus may further include an evaporator fluidly connected to the storage tank. The apparatus may further include a steam chamber coupled to the evaporator and fluidly connected to a compressor. The apparatus may further include a concentrate storage section attached to the steam chamber via an inflow path and having a concentrate level sensor configured to generate a concentrate level data signal indicating the fill percentage of the concentrate storage section. The concentrate storage section may be coupled to a concentrate flow path. The apparatus may further include a condenser coupled to the compressor outlet and fluidly connected to a condensate flow path. The apparatus may further include a first heat exchanger and a second heat exchanger, each including a heat exchange section of a source fluid flow path from the fluid source. The heat exchange section of the first heat exchanger may exchange heat with the condensate flow path, while the heat exchange section of the second heat exchanger may exchange heat with the concentrate flow path. The heat exchange section of the source fluid flow path may be downstream of the source proportioning valves. The device may further include at least one distillate sensor in communication with the condensate flow path at a point downstream of the first heat exchanger. The device may further include a controller configured to determine the total open state time of the source proportional valves based at least in part on a concentrate data signal and a target concentrate rate. The controller may be configured to assign a percentage of the total open state command to each source proportional valve based on at least one distillate sensor data signal from at least one distillate sensor.

[0117] In some embodiments, the condenser may include a condenser section and a condensate accumulation section. In some embodiments, the condenser may be in fluid communication with a condensate storage section including a condensate level sensor configured to monitor the level of condensate in the condensate storage section and generate a condensate data signal indicating the fill percentage of the condensate accumulation section. The condensate storage section may be located between the condenser and the concentrate stream. In some embodiments, a controller may be configured to maintain a target fill percentage of the condensate accumulation section based on the output of a PID control loop that uses the target fill percentage and the difference between the target fill percentage and the current fill percentage as indicated by the condensate data signal as input. In some embodiments, the target fill percentage may be equal to at least one liter and less than two liters. In some embodiments, the condenser may be in fluid communication with a condensate storage section including a condensate level sensor configured to monitor the level of condensate in the condensate storage section and generate a condensate data signal indicating the fill percentage of the condensate storage section. The condensate storage section is located between the condenser and the concentrate stream. In some embodiments, at least one distillate sensor may include a temperature sensor. In some embodiments, the at least one distillate sensor data signal may be a temperature data signal indicating the current condensate temperature after passing through the heat exchanger. In some embodiments, the controller may be configured to assign a percentage of the total open state command to each source proportional valve based on a control loop, wherein the control loop uses a target condensate temperature and the current condensate temperature as inputs. In some embodiments, the target temperature may be at least 35°C but not more than 40°C. In some embodiments, the target temperature may be at least 20°C but not more than 30°C.

[0118] According to another embodiment of this disclosure, the distillation system may include a distillation apparatus selectively fluidly connected to a fluid source via a set of source proportioning valves. The distillation apparatus may have a concentrate output coupled to a concentrate path and a condensate output coupled to a condensate path. The system may further include a first heat exchanger and a second heat exchanger, each including a heat exchange portion of a source fluid path from a fluid source downstream of the source proportioning valves. The heat exchange portion of the first heat exchanger may be in heat exchange relationship with the condensate path, while the heat exchange portion of the second heat exchanger may be in heat exchange relationship with the concentrate path. Each heat exchanger may have a dedicated source proportioning valve. The system may further include a condensate sensor assembly in communication with the condensate path at a point downstream of the first heat exchanger. The system may further include a controller configured to, in a first operating state, distribute a command flow of source fluid from the fluid source between the source proportioning valves based on a first target temperature and the difference between the first target temperature and the current concentrate temperature received by the controller from the condensate sensor assembly. In the second mode, the controller can be configured to distribute all command flows to the source proportional valve dedicated to the second heat exchanger and open the source proportional valve dedicated to the first heat exchanger with a duty cycle that may not exceed a predetermined limit.

[0119] In some embodiments, the predetermined limit may be 5%. In some embodiments, the predetermined limit may be 2%. In some embodiments, the condensate sensor assembly may include redundant temperature sensors. In some embodiments, the first heat exchanger and the second heat exchanger may be helical and formed by winding the heat exchangers around the exterior of the distillation apparatus. 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 may be at least 35°C but not greater than 40°C. In some embodiments, the controller may be configured to open a source proportional valve dedicated to the first heat exchanger based on a second target temperature and the difference between the second target temperature and the current concentrate temperature in the 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 greater than 95°C and less than 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 disposed in the evaporator storage section and in fluid communication with the evaporator of the distillation apparatus. The controller may be configured, in a second operating state, to determine a total flow command based at least in part on an evaporator level data signal indicating the water level in the water column of the evaporator storage section. In some embodiments, the first target temperature may be at least 20°C but not greater than 30°C. In some embodiments, the first target temperature is 25°C.

[0120] According to another embodiment of this disclosure, a method for controlling and distributing the flow of source fluid into a distillation apparatus may include: sensing the level of concentrated material in a concentrated material storage section fluidly connected to the evaporator of the distillation apparatus using a concentrated material level sensor. The method may further include: sensing the temperature of the product fluid produced by the distillation apparatus at a point downstream of a product heat exchanger, wherein the product heat exchanger allows the product fluid to exchange heat with the incoming source fluid. The method may further include: determining a concentrated material accumulation rate based on the concentrated material level using a processor. The method may further include: calculating a first difference between the concentrated material accumulation rate and a first target concentrated material accumulation rate, and a second difference between the concentrated material accumulation rate and a second target concentrated material accumulation rate using a processor. The method may further include: determining a first temporary open state command and a second temporary open state command for a first source inflow proportional valve and a second source inflow proportional valve using a processor. The first temporary open state command may be based on the first difference, and the second temporary open state command may be based on the second difference. The method may further include: calculating a final open state command using a processor based on a temporary open state time command. The method may further include: when the processor is in a first operating state, assigning a final open state command between a first source inflow proportional valve and a second inflow proportional valve. The first source inflow proportional valve may lead to a product heat exchanger. This assignment may be based on the difference between the target product temperature and the temperature of the product fluid. The method may further include: when the processor is in a second operating state, assigning the entire final open state command to the second source inflow proportional valve. The method may further include: when the processor is in the second operating state, opening the first source inflow proportional valve via a command from the processor at a duty cycle not exceeding a predetermined limit.

[0121] In some embodiments, the first target accumulation rate may be greater than the second target accumulation rate. In some embodiments, calculating the final open state command may include inputting a first temporary open state command and a second temporary open state command into the slider. In some embodiments, calculating the final open state command may include generating a mixing command based on the first temporary source open state command and the second temporary source open state command. In some embodiments, calculating the final open state command may include determining a first state fraction and a second state fraction, and multiplying the first temporary open state command by the first state fraction, while multiplying the second temporary open state command by the second state fraction. In some embodiments, calculating the final open state command includes adjusting the command from primarily a first temporary open state command to primarily a second temporary open state command during the transition between the first operating state and the second operating state. In some embodiments, calculating the final open state command may include adjusting the command from a purely first temporary open state command to a purely second temporary open state command during the transition between the first operating state and the second operating state. In some embodiments, the second operating state may be a hot distillate production state. In some embodiments, the allocation may include determining the open state command of the first source inflow proportional valve based on the difference between the target product temperature and the temperature of the product fluid, and determining the open state command of the second source inflow proportional valve by subtracting the open state command of the first source inflow proportional valve from the final open state command. In some embodiments, the predetermined limit may be a limit of less than 5%. In some embodiments, the predetermined limit may be a limit of less than 2%. In some embodiments, determining the second temporary open state command may further include: sensing the liquid level of the liquid column in the evaporator storage section, which is in fluid communication with the evaporator, using an evaporator level sensor. The second temporary open state command may be based in part on the difference between the liquid level of the liquid column and a target liquid level of the liquid column. In some embodiments, the second temporary open state command may be based on the rate of change of the difference between the liquid level of the liquid column and the target liquid level of the liquid column.

[0122] According to embodiments of this disclosure, a medical system may include at least one concentrated fluid. The system may further include a distillation apparatus 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 that are in heat exchange relationship with each other. The system may further include a medical device that may include a therapeutic fluid preparation circuit selectively fluidly connected to the purified product water flow path via a point valve. The medical device may include a therapeutic device processor configured to command the at least one concentrated fluid and purified water to mix to generate a prescribed therapeutic fluid through the therapeutic fluid preparation circuit. The system may further include a communication link between the therapeutic device processor of the medical device and the distillation device processor of the distillation apparatus. The medical device processor may be configured to transmit mode commands to the distillation device processor. The system may further include a sensor assembly in communication with the purified product water flow path. The system may further include a source valve between the fluid source and the source fluid flow path. The distillation device processor may be configured to actuate the source valve at least in part based on mode commands and data from the sensor assembly.

[0123] In some embodiments, the sensor assembly may include at least one temperature sensor and at least one conductivity sensor. In some embodiments, the distillation apparatus processor may be configured to actuate the source valve based at least in part on a mode command and temperature data from the sensor assembly. In some embodiments, the distillation apparatus processor may be configured to actuate the source valve based at least in part on a mode command, data from the sensor assembly, and a target setpoint for the 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 apparatus processor based on a mode command. In some embodiments, the target setpoint may be based on a first mode command in the mode commands, which may be in the range of 20° to 30°, and the target setpoint may be based on a second mode command in the mode commands, which may be greater than 90°.

[0124] In some embodiments, the medical device may be a dialysis machine. In some embodiments, the medical device may be a hemodialysis device. In some embodiments, the therapeutic 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 one liter. In some embodiments, the distillation unit processor may be further configured to control the operation of the compressor motor of the distillation unit at least in part based on mode commands. In some embodiments, the distillation unit processor may be further configured to control the operation of the concentrate outlet valve of the distillation unit at least in part based on mode commands.

[0125] According to embodiments of this disclosure, a medical system may include a distillation apparatus having: an evaporator; a source inlet flow path leading to a source input in fluid communication with the evaporator; a condenser; and a purified product water output flow path in fluid communication with the condenser. The system may further include a first filter and a second filter 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 device including a therapeutic fluid preparation circuit selectively in fluid communication with the purified product water output flow path via a point valve. The system may further include a communication link between a therapeutic device processor of the medical device and a distillation device processor of the distillation apparatus. 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 therapeutic device processor may be configured to perform a second filter replacement check, and, if either the first or second filter replacement check fails, command the distillation device processor to enter a filter replacement mode via the communication link.

[0126] In some embodiments, a second filter replacement check may include a control limit check of the number of days elapsed since the installation of the first and second filters. In some embodiments, the medical device may include a graphical user interface. In some embodiments, a second filter replacement check may include a check of user input on the graphical user interface against at least one predetermined standard. In some embodiments, the system may further include a sampling port disposed between the first and second filters, and the predetermined standard may be a water chemistry test strip standard. In some embodiments, the water chemistry test strip standard may be a chlorination level standard. In some embodiments, a distillation device processor may be configured to command a flushing of the first and second filters prior to at least one of a first filter replacement check or a second filter replacement check. In some embodiments, a distillation device processor may be configured to perform a first filter replacement check based on filter output pressure data signals from a second pressure sensor. In some embodiments, a distillation device processor may be configured to indicate a failure of the first filter replacement check when the filter output pressure is below a threshold. In some embodiments, a distillation device processor may be configured to perform a first filter replacement check based on the difference between the pressure upstream of the first and second filters as indicated by the first pressure sensor and the pressure downstream of the first and second filters as indicated by the second pressure sensor. In some embodiments, a distillation device processor may be configured to indicate a failure of the first filter replacement check when the difference is less than a threshold.

[0127] According to another embodiment of this disclosure, a medical system may include a distillation apparatus having a source water input and a fluid output flow path. The system may further include a medical device comprising a plurality of fluid flow paths, a plurality of valves, at least one fluid pump, and a fluid inlet selectively fluidly connected to the fluid output flow path via a point valve. The system may further include a communication link between the medical device and the distillation apparatus. The system may further include a sensor assembly in communication with the fluid output flow path. The system may further include a treatment device processor configured to actuate the plurality of valves and the at least one fluid pump to pump a high-temperature fluid through the plurality of fluid flow paths. The system may further include a distillation apparatus processor configured to control the operation of the distillation apparatus based on at least one data signal from the sensor assembly and mode commands sent from the treatment device processor of the medical device via the communication link, to generate a high-temperature fluid during a first time period and output the high-temperature fluid to the fluid output flow path, wherein during the first time period the distillation apparatus processor commands the point valve to open, and during the second time period the distillation apparatus processor commands the point valve to close and commands the valve leading to the flow path fluidly connected to the fluid output flow path to open.

[0128] In some embodiments, the source water input may be in fluid communication with a non-temperature-controlled fluid source. In some embodiments, the medical device may be a dialysis machine. In some embodiments, the medical device may be a hemodialysis machine. In some embodiments, the plurality of 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 plurality of fluid flow paths may be included at least in a blood pump cartridge and a dialysate pump cartridge. In some embodiments, the medical device may include a fluid storage unit, and the treatment device processor may be configured to send a signal to the distillation device processor to end a first time period based on the amount of high-temperature fluid contained in the fluid storage unit. In some embodiments, the medical 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 in part 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 the at least one data signal and another mode command sent from the treatment device processor via a communication link to generate a medical fluid component and output the generated medical fluid component to a fluid output flow path. In some embodiments, the plurality of flow paths may include a medical fluid mixing loop, and the treatment device processor may be configured to command the operation of the at least one pump and the plurality of valves to mix a medical fluid component with at least one concentrate in fluid communication with the plurality of flow paths according to a predetermined prescription.

[0129] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features and advantages will become apparent from the specification, drawings, and claims. Attached Figure Description

[0130] These and other aspects will become more apparent from the following detailed description of various embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0131] Figure 1 A schematic diagram of an example water purification system is shown;

[0132] Figure 2 Another example schematic diagram of a water purification system is shown;

[0133] Figure 3 Another example schematic diagram of a water purification system is shown;

[0134] Figure 4 Another example schematic diagram of a water purification system is shown;

[0135] Figure 5 It shows Figure 1 An exemplary embodiment of the system shown;

[0136] Figures 6 to 7 A view of a portion of the system is shown, with the hot section housing of the system removed;

[0137] Figure 8 A view of an exemplary heat exchanger is shown;

[0138] Figure 9 It shows Figure 8 A cross-sectional view of a portion of an exemplary heat exchanger 6008;

[0139] Figure 10 A cross-sectional view of an example purifier filled with active fluid is shown;

[0140] Figure 11 An exploded view of a portion of the air purifier is shown;

[0141] Figure 12 A top view of a portion of the purifier is shown, with a section of the concentrate storage compartment cut off;

[0142] Figure 13 A cross-sectional view of an example concentrate storage section is shown;

[0143] Figures 14 to 15 A perspective view showing the internal volume of an example steam chamber is provided.

[0144] Figure 16 Another cross-sectional view of the example concentrate storage section is shown;

[0145] Figure 17 A perspective view of an example purifier and concentrate storage section is shown;

[0146] Figure 18 An exploded view of an example steam chamber and demister is shown;

[0147] Figures 19 to 20 A view of an example flow path cyclone is shown;

[0148] Figure 21 A view of an example drip tray is shown;

[0149] Figure 22 An exploded view of the drip tray and demister is shown;

[0150] Figure 23 An example compressor, derived from an example steam chamber, is shown;

[0151] Figure 24 An exploded view of an example compressor is shown;

[0152] Figure 25 Another exploded view of the example compressor is shown;

[0153] Figure 26 A top view of an example compressor is shown;

[0154] Figure 27 and Figure 28 It shows in Figure 26 A cross-section taken at a specified plane;

[0155] Figure 29 Another top view of the example compressor is shown;

[0156] Figure 30 and Figure 31 It shows in Figure 29 A cross-section taken at a specified plane;

[0157] Figure 32 A view of an example purifier is shown, with the steam chamber, demister, and condenser inlet connector broken down.

[0158] Figure 33 A perspective view of an example condenser inlet, including a window, is shown;

[0159] Figure 34 A cross-sectional view of an example purifier is shown, illustrating the high-pressure steam inside the purifier;

[0160] Figure 35 A perspective view of another example condenser inlet is shown;

[0161] Figure 36A side view of the evaporator and condenser of an example purifier is shown, with a portion of the product storage section cut off;

[0162] Figure 37 A perspective view of an example air purifier is shown, which includes multiple exhaust flow paths;

[0163] Figure 38 A perspective view of an example purifier including multiple product flow paths is shown;

[0164] Figure 39 A side view of an example purifier including multiple product flow paths is shown;

[0165] Figure 40 and Figure 41 An example sensing manifold is shown;

[0166] Figure 42 and Figure 43 A perspective view of an example mixing tank is shown;

[0167] Figure 44 A side view of an example air purifier is shown, in which the pivot of the example support plate of the air purifier is decomposed;

[0168] Figure 45 A side view of an example air purifier is shown, with the fasteners connecting the first and second sections of the air purifier removed.

[0169] Figure 46 A side view of an example air purifier is shown, in which the fasteners connecting the first and second sections of the air purifier are removed, and the first section is moved away from the second section along a displacement path;

[0170] Figure 47 A side view of an example air purifier is shown, in which fasteners connecting the first and second sections of the air purifier are removed, and the first section is moved away from the second section about an arcuate path defined by a pivot.

[0171] Figure 48 It shows something similar to Figure 3 The example system shown is a front perspective view of the example system.

[0172] Figure 49 It shows Figure 48 The example system shown is a rear perspective view;

[0173] Figure 50 A front perspective view of the example system is shown, with a portion of the example system's shell removed;

[0174] Figure 51 A rear perspective view of the example system is shown, with a portion of the example system's shell removed;

[0175] Figure 52 A perspective view of a portion of an example purifier, including multiple source fluid flow paths, is shown.

[0176] Figure 53 A perspective view of a portion of an example purifier, including multiple source fluid flow paths, is shown.

[0177] Figure 54 A side view of an example source inlet manifold is shown;

[0178] Figure 55 A side view of an example product heat exchanger manifold is shown;

[0179] Figure 56 A view of an exemplary heat exchanger is shown;

[0180] Figure 57 It shows Figure 56 A cross-sectional view of a portion of an exemplary heat exchanger 6008;

[0181] Figure 58 A top view of an example air purifier is shown;

[0182] Figure 59 It shows in Figure 58 A cross-sectional view taken at the indicated plane, extending through the product storage section and product level sensor of the purifier;

[0183] Figure 60 An exploded view of an example evaporator and condenser of the air purifier is shown;

[0184] Figure 61 Another exploded view of an example evaporator and condenser of the air purifier is shown;

[0185] Figure 62 It shows Figure 61 A magnified view of the indicated area;

[0186] Figure 63 It shows in Figure 58 A cross-sectional view taken at the indicated plane, extending through the discharge storage section and discharge level sensor of the purifier;

[0187] Figure 64 A view of a portion of an example air purifier is shown, with a section of the steam chamber of the example air purifier cut off;

[0188] Figure 65 It shows Figure 64 A magnified view of the indicated area;

[0189] Figure 66 A cross-sectional view of an example discharge storage unit and discharge level sensor is shown;

[0190] Figure 67 A perspective view of a portion of an example purifier, including multiple discharge paths, is shown.

[0191] Figure 68 An exploded view of an example steam chamber is shown;

[0192] Figure 69 An example steam chamber and compressor are shown, which is disassembled from the steam chamber;

[0193] Figure 70 An example compressor and steam chamber are shown, with the compressor disassembled.

[0194] Figure 71 An exploded view of an example compressor is shown;

[0195] Figure 72 A top view of an example compressor and steam chamber is shown;

[0196] Figure 73 It shows in Figure 72 A cross-sectional view taken at the plane indicated;

[0197] Figure 74 It shows in Figure 72 A cross-sectional view taken at the plane indicated;

[0198] Figure 75 A top view of an example compressor and steam chamber is shown;

[0199] Figure 76 It shows in Figure 75 A cross-sectional view taken at the plane indicated;

[0200] Figure 77 It shows in Figure 75 A cross-sectional view taken at the plane indicated;

[0201] Figure 78 An exploded view of an example evaporator condenser and steam chamber is shown, which is separated from the evaporator condenser.

[0202] Figure 79 A cross-sectional view of an example purifier is shown, extending through the midplane of the product storage section and the product storage level sensor of the example purifier;

[0203] Figure 80 A perspective view of a portion of an example purifier, including multiple exhaust flow paths, is shown.

[0204] Figure 81 An exploded view of an example mixing storage section and a discharge heat exchanger manifold is shown;

[0205] Figure 82A perspective view of a portion of an example purifier, including multiple product flow paths, is shown.

[0206] Figure 83 An exploded view of the example product heat exchanger manifold is shown;

[0207] Figures 84A-84B A flowchart detailing the many state changes that may occur during the operation of the example system is shown;

[0208] Figure 85 A flowchart depicting several example actions that can be used in an integrity test state is shown;

[0209] Figure 86 A flowchart is shown that details several example actions that can be used in the system's filled state;

[0210] Figure 87 A flowchart is shown that details several example actions that can be used during the filling of the purifier;

[0211] Figure 88 A flowchart is shown that details several example actions that can be used under the thermal conditions of the system;

[0212] Figure 89 A flowchart detailing several example actions that can flush the system's filter is shown;

[0213] Figure 90 A flowchart detailing several example actions that can be used to dispense water samples is shown;

[0214] Figure 91 A flowchart detailing several example actions of a system for filter replacement is shown;

[0215] Figure 92 A flowchart is shown that details several example actions that can be used in the production-ready state of the system.

[0216] Figure 93 A flowchart is shown that details several example actions that can be used in the production startup state of the system;

[0217] Figure 94 A flowchart is shown that details several example actions that can be used in the water production state of the system;

[0218] Figure 95 A flowchart is shown that details several example actions that can be used in the hot water production preparation state of the system;

[0219] Figure 96A flowchart is shown that details several example actions that can be used in the hot water production state of the system;

[0220] Figure 97 A flowchart is shown that details several example actions that can be used in the hot water production state of the system when the system is in self-disinfection mode;

[0221] Figure 98 A flowchart detailing several example actions that can be used in the system's standby state is shown;

[0222] Figure 99 A flowchart detailing several example actions that can be used to control the liquid level in a purifier is shown;

[0223] Figure 100 An example product temperature control graph is shown;

[0224] Figure 101A-101B Another example product temperature control graph is shown;

[0225] Figure 101C It shows that for Figure 101B An alternative temperature control chart is shown for a portion of the control chart, in which both product temperature and discharge temperature are controlled;

[0226] Figure 102 A flowchart detailing several example actions that can be used to determine the filling rate of the storage section is shown;

[0227] Figure 103 A flowchart detailing several example actions that can be used to update fill rate decisions using fill rate estimates is shown;

[0228] Figure 104 A flowchart is shown that details several example actions that can be used to adjust the target discharge rate value;

[0229] Figure 105A A flowchart is shown that details several example actions that can be used to adjust the source proportional valve command;

[0230] Figure 105B A flowchart is shown that details several example actions that can be used to adjust the source proportional valve command;

[0231] Figure 106A-106B A flowchart detailing several example actions that can be used to determine source proportional valve commands is shown;

[0232] Figure 107 A flowchart is shown that details many example actions that can be used to divert product water;

[0233] Figure 108 A flowchart is shown that details several example actions that can be used to monitor errors during system operation;

[0234] Figure 109 A flowchart detailing several example actions that can be used to control the liquid level in a purifier is shown;

[0235] Figure 110 A flowchart detailing several example actions that can be used to control the motor of a compressor is shown;

[0236] Figure 111 A flowchart detailing several example actions that can be used to automatically calibrate rated motor speed values ​​is shown;

[0237] Figure 112 A flowchart depicting several example actions that can be used to automatically calibrate motor speed setpoints is shown;

[0238] Figure 113 A flowchart depicting several example actions that can be used to automatically calibrate motor speed setpoints is shown;

[0239] Figure 114 A flowchart 7960 is shown depicting several example actions that can be used to automatically calibrate the motor speed setpoint;

[0240] Figure 115 A flowchart detailing several example actions that can be used to control the liquid level within the purifier is shown;

[0241] Figure 116 A flowchart is shown that details several example actions that can be used to monitor errors during system operation;

[0242] Figure 117 An example heater control diagram is shown;

[0243] Figure 118 A flowchart detailing several example actions that can be used to determine the feedforward commands of a compressor motor controller is shown.

[0244] Figure 119 A flowchart is shown that details several example actions that can be used to monitor errors during system operation;

[0245] Figure 120 A block diagram of a system including a bearing feed flow sensor is shown;

[0246] Figure 121 Flowcharts detailing several example actions that can be used to monitor flow from a bearing feed pump are shown;

[0247] Figure 122A flowchart detailing several example actions that can be used to determine the product storage section outlet valve command is shown;

[0248] Figure 123 The flowcharts show several example actions that can be used to adjust the duty cycle of the product storage section outlet valve based on data from product level sensors and product temperature sensors.

[0249] Figure 124 Flowcharts detailing several example actions that can be used to adjust the duty cycle of the storage section outlet valve based on data from the product level sensor are shown.

[0250] Figure 125 Flowcharts detailing several example actions that can be used to adjust the duty cycle of the product storage section outlet valve based on data from one or more product temperature sensors are shown.

[0251] Figure 126 A flowchart depicting several example actions that can be used to determine the presence of abnormal source water temperatures within a system is shown;

[0252] Figure 127 A flowchart depicting several example actions that can be used to regulate the temperature setpoint of a process flow is shown;

[0253] Figure 128 A flowchart is shown that details several example actions of an electronic component cooling valve that can be used in a control system;

[0254] Figure 129 Flowcharts depicting several example actions of cooling the housing of electronic components that can be used in a control system are shown; and

[0255] Figure 130 A flowchart depicts several example actions that can be performed to control the temperature of the discharge process flow output from the heat exchanger.

[0256] Similar reference symbols in the various figures indicate similar elements. Detailed Implementation

[0257] Figure 1A schematic diagram of an exemplary water purification system 6000 is shown. System 6000 draws water from a source 6002 and purifies it to remove various contaminants, making the water suitable for consumption at the point of use. The point of use in this exemplary diagram is a medical system 6004. In some examples, the purified output of system 6000 may be used as a component of medical fluids used by medical system 6004. However, system 6000 may be used to provide water for drinking purposes or for other devices requiring water to meet specific quality standards. Medical system 6004, which may be used with purification system 6000, may include various dialysis systems. Medical system 6004 may be a system for mixing therapeutic agents such as dialysate. Medical system 6004 may also orchestrate dialysis (peritoneal or hemodialysis) treatment for patients. In a specific example, medical system 6004 may be a peritoneal dialysis fluid mixing system or a hemodialysis system, such as those systems described in the following patents: U.S. Patent Application No. 12 / 072,908, filed February 27, 2008, entitled “Hemodialysis Systems and Methods,” now U.S. Patent No. 8,246,826, published August 21, 2012 (Attorney-in-charge F65); U.S. Patent Application No. 12 / 199,055, filed August 27, 2008, entitled “Enclosure for Portable Hemodialysis System,” now U.S. Patent No. 8,393,690, published March 12, 2013 (Attorney-in-charge G20); and U.S. Non-Provisional Patent Application No. 29, March 2019, entitled “Liquid Pumping Cassettes and Associated Pressure Distribution Manifold and Related Methods (Liquid pumping box and associated pressure distribution manifold and associated methods) (Agent's Reference No. Z35), all of which are incorporated herein by reference in their entirety.

[0258] The various systems, methods, and apparatuses described in the following patents may be used with any one or more embodiments of the water distillation apparatus, methods, and approaches described herein: U.S. Patent Application No. 13 / 952,263, filed July 26, 2013, entitled “Water Vapor Distillation Apparatus, Method and System,” now U.S. Patent No. 9,604,858 (Attorney’s Reference No. K95), published March 28, 2017, the entire contents of which are incorporated herein by reference; and U.S. Patent Application No. 10 / 713,617, filed November 13, 2003, entitled “Pressurized Vapor Cycle Liquid Distillation,” now U.S. Patent No. 7,597,784 (Attorney’s Reference No. D91), published October 6, 2009, the entire contents of which are incorporated herein by reference. Therefore, other embodiments are contemplated, some of which include one or more apparatuses, systems, and methods described in the foregoing references.

[0259] As shown, water can travel from source 6002 to at least one filter 6006. Source 6002 may be a source 6002 that meets the U.S. EPA requirements for drinking water. Source 6002 may, for example, meet the requirements of the National Drinking Water Standard (40 CFR 141), the entire contents of which are incorporated herein by reference. It should be noted that this disclosure is not bound by any definitions provided in Section 141.2 or any other portion thereof contained in the foregoing references. In a particular embodiment, source or source fluid storage unit 6002 may be a residential water supply line that distributes water from a municipal or private water supply. The at least one filter 6006 may be an activated carbon filter. Other types of filters may also be used that remove intended and undesirable components (one or more) from the water of source 6002, such as oxidants, such as chlorine, chloramines, etc. In some embodiments, system 6000 may include two redundant filters 6006. Water can flow from the at least one filter 6006 to one or more heat exchangers 6008A, 6008B.

[0260] In an example embodiment, a first heat exchanger 6008A and a second heat exchanger 6008B are shown. These heat exchangers 6008A and 6008B may be counter-current heat exchangers. The fluid entering each heat exchanger 6008A and 6008B may be in heat exchange relationship with at least one process flow from the water purifier 6010 of system 6000. The at least one process flow in each heat exchanger 6008A and 6008B may be different process flows, but heat exchangers 6008A and 6008B may also carry at least one common process flow to each other. In the case where a single heat exchanger carries multiple flows, the flows may be separated as described with respect to any heat exchanger described herein. In a particular embodiment, one heat exchanger 6008A may carry a purified or product process flow, while the other may carry all other process flows (leakage, entrapment, exhaust gases, volatiles, or other waste process flows) from the water purifier 6010. Such heat exchangers 6008A and 6008B can be called product heat exchangers and discharge heat exchangers, respectively.

[0261] One or more valves may be included to provide control over the proportion of filtered source water flowing to one heat exchanger (6008A, 6008B) and the other heat exchanger (6008A, 6008B). This allows for more or less variation in the temperature of the water flowing from the at least one filter 6006 through each heat exchanger 6008A, 6008B. Similarly, this allows for more or less variation in the temperature of the process flow traveling through heat exchangers 6008A, 6008B. In some embodiments, because the proportion of incoming fluid for each heat exchanger 6008A, 6008B is manipulated, the total mass flow rate or total incoming fluid from the at least one filter 6006 through both heat exchangers 6008A, 6008B can be generally constant, or it can be controlled by other unrelated control algorithms. The total mass flow rate of the fluid from the at least one filter 6006 through the heat exchangers 6008A, 6008B can also fluctuate in series with this proportion.

[0262] The filtered source water can be recombined from heat exchangers 6008A and 6008B and enter purifier 6010 for purification. Purifier 6010 can remove or reduce the concentration of at least one contaminant and possibly multiple contaminants in the source water. Water purifier 6010 can be any steam distillation apparatus described herein, but other distillation apparatuses or water purification apparatuses may also be used. In example system 6000, water purifier 6010 is capable of purifying water to a quality standard sufficient to support the use of purified water in medical system 6004. The water may, for example, conform to quality standards issued by government organizations, standards organizations, non-governmental organizations, or other appropriate organizations. In the case that medical system 6004 is a dialysis system, the standards may be, for example, those in the USP Water for Hemodialysis Monograph, which is incorporated herein by reference in its entirety.

[0263] The water purifier 6010 can generate multiple process flows. These process flows can be fluid flows and may include, but are not limited to, product water flows, discharge water flows, and gaseous exhaust flows. Some of these flows, after being generated in the water purifier 6010, may be contained in process flow storage sections. In the example illustration, a product water storage section 6012 and a discharge water storage section 6014 are included. These storage sections 6012, 6014 may include internal volumes designed to accommodate a certain volume of fluid from their respective process flows. Each storage section 6012, 6014 may also include a level sensor to determine the volume of the corresponding process flow in each storage section.

[0264] The process flow can exit the water purifier 6010 or storage units 6012, 6014 and proceed to the heat exchangers 6008A, 6008B of the system 6000. As these flows pass through the heat exchangers 6008A, 6008B, heat transfer may occur between the process flow and the source water along the route from the at least one filter 6006 to the purifier 6010. Typically, the process flow can transfer heat to the source water, thereby cooling the process flow and raising the temperature of the source water. In the case of a gaseous process flow passing through the heat exchangers 6008A, 6008B, the heat exchange can cause at least a portion of the gaseous process flow to condense.

[0265] As described above, the mass ratio of the source water passing through each heat exchanger can be varied. For example, the mass ratio can be controlled to ensure that the product stream temperature conforms to a predetermined temperature range or threshold. This temperature requirement can be an acceptable operating temperature range or threshold for medical system 6004. Medical system 6004 can accept water at temperatures below a certain threshold and / or within a certain range, and the mass ratio of the source water flow can be controlled to ensure that the product stream conforms to any such standard. In the case of medical system 6004 being a hemodialysis system, the threshold can be near average human body temperature (e.g., 37°C + / - 5°C).

[0266] Additionally, system 6000 may include at least one sensor assembly 6016. This at least one sensor assembly 6016 may monitor one or more characteristics of interest in one or more process flows. Potential characteristics of interest may include, but are not limited to, temperature, concentration of dissolved ions, conductivity, optical properties, turbidity, presence of specific compounds or elements, and any other water quality characteristics described elsewhere herein. In some specific embodiments, sensor assembly 6016 may monitor the mass of water leaving the first heat exchanger 6008A or the product heat exchanger 6008A. Conductivity and temperature may be measured, for example. Data from the at least one sensor assembly 6016 may provide feedback to a controller (e.g., P, PI, PID) that manages the proportion of source water flowing through each heat exchanger 6008A, 6008B. Furthermore, data from the at least one sensor assembly 6016 may inform the operation of a diversion valve, thereby allowing the product water flow to proceed to medical system 6004 or to discharge point 6018 or a waste location. For example, if the conductivity of the product water is greater than a predetermined threshold, a diversion valve can be actuated to divert the product water to the discharge point 6018 until the conductivity drops to an acceptable level.

[0267] Discharge point 6018 can also be used to receive any excess product water generated by water purifier 6010. If medical system 6004 does not require water and product storage unit 6012 is full, product water can be diverted to discharge point 6018. Discharge point 6018 can also receive other process streams from water purifier 6010, such as discharge streams and any other waste streams. Discharge point 6018 can be any suitable destination, such as a municipal discharge point.

[0268] Now for reference Figure 2 It shows the source Figure 1Another representative block diagram of an example system 6000. Example system 6000 includes a source check valve 6030 that allows unidirectional flow from source 6002 to the remainder of system 6000. Additionally, a shut-off valve 6032 is included. This shut-off valve 6032 may be mechanical (e.g., a ball valve) or may be operated by a controller 6034. In the event of a fault condition or other adverse condition, the shut-off valve 6032 may be actuated to prevent source fluid from entering the system. Example system 6000 also includes a pressure sensor 6036 that can communicate data with controller 6034 and sense the pressure of incoming source water.

[0269] The exemplary system 6000 includes a first filter 6006A and a second filter 6006B. In some embodiments, an additional coarse filter (not shown) may be included upstream of the first filter 6006A and the second filter 6006B to prevent the ingress of large deposits. The first filter and the second filter 6006A, 6006B may be activated carbon filters (e.g., 5L to 6L activated carbon filters). These filters 6006A, 6006B can be used as elements for the removal of organic contaminants and / or oxidants, and can remove chemicals such as chlorine, chloramines, etc., from source water.

[0270] In a particular embodiment, the first filter 6006A and the second filter 6006B may be substantially identical redundant filters. Filters 6006A and 6006B may be separated by a fluid flow path including a test or sampling port 6038. The sampling port 6038 may allow a user to periodically (e.g., before each use or according to another predetermined schedule) aspirate fluid filtered through the first filter 6006A for manual testing.

[0271] Sampling port 6038 may include a valve (e.g., a manually operated valve) that, when actuated, allows sample dispensing into a test container or the like. In some embodiments, sampling port 6038 may be accompanied by a button that mechanically opens a water flow path to allow water to proceed for dispensing through sampling port 6038. Controller 6034 may also receive a signal when the button is pressed. In some embodiments, when controller 6034 receives a button press signal, the sampling valve may be actuated by the controller and commanded to open by controller 6034. Sampling port 6038 may be associated with a user interface, such as a graphical user interface, and the button may be a soft button displayed on a touchscreen. In other embodiments, the user interface may be simple and include one or more lights (e.g., LEDs) to convey status information (power, system status, sample ready, fault, etc.).

[0272] Manual testing may depend on the type of chemical substance that may be present in source 6002 and may include free chlorine and / or total chlorine testing. In alternative embodiments, instead of or in addition to test port 6038, an instrument (e.g., a chlorine meter) may be included for sensing the concentration of the expected chemical substance. This instrument may communicate data with controller 6034, which may analyze data generated via the instrument. Test port 6038 and / or the instrument may allow the user to determine when filters 6006A, 6006B need to be replaced. In some embodiments, system 6000 may prevent operation of water purifier 6010 until controller 6034 receives a signal indicating acceptable filtration of water leaving first filter 6006A. Alternatively or additionally, medical system 6004 may refuse water from system 6000 unless it receives a data signal indicating acceptable filtration from first filter 6006A. In the case of manual testing, this signal may be generated via a user interface input to system 6000 or via a user interface input to medical system 6004. The signal may also be generated by a test instrument.

[0273] After passing through the second filter 6006B, the filtered source water can enter the valve manifold 6039. Upon entering the valve manifold 6039, the water pressure can be regulated to a predetermined pressure by the pressure regulator 6040. This predetermined pressure can be between 15 psig and 30 psig (e.g., 20 psig). The water pressure and temperature can be sensed by pressure sensor 6044 and temperature sensor 6042, which communicate data with the controller 6034. The filtered source water can then enter the discharge heat exchanger 6008B and the product water heat exchanger 6008A.

[0274] The flow path to the discharge heat exchanger can extend to the electronic component housing 6046 of system 6000. As water travels to the discharge heat exchanger 6008B, the path of the flow path can establish a heat exchange relationship with the electronic components of the electronic component housing 6046. Therefore, filtered source water can be used to cool the electronic components in the electronic component housing 6046 on its way to the discharge heat exchanger 6008B. Alternatively or additionally, the source water on its way to the product heat exchanger 6008A can be arranged to have a heat exchange relationship with the electronic components of the electronic component housing 6046. As shown, the electronic component housing 6046 can be associated with an electronic component temperature sensor 6048 that provides temperature data to the controller 6034. In some embodiments, multiple temperature sensors 6048 may be present in the electronic component housing 6046 for increased redundancy and / or monitoring of specific components (e.g., power modules).

[0275] Source proportioning control valves 6050A and 6050B can be operated by controller 6034 to control the mass proportion of source water flowing through each of the discharge heat exchanger 6008B and the product heat exchanger 6008A. As mentioned above, the mass proportion can be selected to achieve a desired temperature in one or more of the process streams from water purifier 6010. However, it should be noted that the mass proportion can also be controlled to ensure adequate cooling of the electronic component housing 6046. In some embodiments, at least a predetermined proportion of the incoming source water can be supplied to the discharge heat exchanger 6008B to ensure adequate cooling. Controller 6034 can also change the mass proportion of heat exchangers 6008A and 6008B if temperature data from electronic component temperature sensor 6048 indicates that the temperature of electronic component housing 6046 is above a threshold.

[0276] After passing through the feed heat exchanger 6008B and the product heat exchanger 6008A, the filtered source water flow can be recombined through the source fluid input included in the storage tank 6052 and enter the storage tank 6052 of the water purifier 6052. The storage tank 6052 may include at least one heating element 6054. The at least one heating element 6054 may be a resistance heater. A thermal fuse 6056 may also be included as a fail-safe measure. The at least one heating element 6054 may heat the contents of the storage tank 6052 based on the analysis of data from the storage tank temperature sensor 6058 by the controller 6034. Each heating element 6054 may be associated with a temperature sensor 6059 to provide data on the temperature at the heating element 6054. The at least one heating element 6054 may provide heat energy to the incoming source water to help or cause the source water in the evaporator 6060 of the water purifier 6010 to evaporate. The evaporator 6060 may be formed at least in part by a shell-and-tube type heat exchanger as described elsewhere in the specification. The top of the evaporator 6060 (relative to gravity) may include a steam chamber 6072. As the source fluid travels toward the steam chamber 6072, the evaporator 6060 can convert the source fluid from the source fluid input into low-pressure steam and concentrated stream.

[0277] When the source water boils, steam can rise from the now more concentrated source water and pass through a demister 6062 located in the steam chamber 6072. The demister 6062 can prevent water molecules still in the liquid phase from leaving the evaporator 6060. The demister 6062 can be any exemplary demister described herein. After removing the mist, the water vapor can proceed to the compressor 6064. The compressor 6064 can be any suitable compressor, such as any compressor described herein. The compressor 6064 can compress the water vapor and increase its temperature in the process. The system 6000 may include a pre-compression temperature sensor 6066 and a post-compression temperature sensor 6068. Data from these temperature sensors 6066, 6068 can be provided to a controller 6034, and the controller 6034 can use this data to control the compressor 6064. A compressor temperature sensor 6070 (or a redundant compressor temperature sensor) may be further included to provide temperature data for the controller 6034 in relation to the compressor 6064.

[0278] In some embodiments, controller 6034 may include multiple processors capable of controlling different components of system 6000. In some embodiments, a main control processor and peripheral control processors may be included in controller 6034. The peripheral control processors may control at least one heating element 6054 and compressor 6064, while the main control processor receives sensor data and controls other components of system 6000. Processors may exchange data to facilitate the division of responsibilities. For example, sensor data and / or high-level commands from the main control processor may be provided to the peripheral control processors. The peripheral control processors may provide their command outputs to the main control processor.

[0279] When pure steam is transferred from evaporator 6060 to compressor 6064, impurities in the source water may concentrate to form a discharge process flow. In an example embodiment, the discharge process flow can pass through evaporator 6060 and enter discharge storage unit 6014. Discharge storage unit 6014 may be configured transverse to and in communication with steam chamber 6072. A discharge level sensor 6074 may be included, which may be associated with discharge storage unit 6014 and communicate with controller 6034. Discharge level sensor 6074 can directly measure and generate a data signal indicating the level of concentrate or discharge in steam chamber 6072. Data from discharge level sensor 6074 can be used by controller 6034 to ensure that a sufficient amount of concentrate is maintained in evaporator 6060 and to confirm the presence of the desired discharge flow rate. When it is necessary to discharge excess fluid from the water purifier 6010, the discharge storage section 6014 and the storage tank 6052 can be directly connected to the discharge point 6018 via a fluid conduit.

[0280] A product water process flow can be formed by condensing steam flowing from the high-pressure steam outlet of compressor 6064 to condenser 6076. At least a portion of this steam can condense on a section of evaporator 6060 communicating with condenser 6076. In various embodiments, condenser 6076 can have heat exchange relations with multiple outer surfaces of evaporator 6060. The latent heat of condensation provided by the condensate within condenser 6076 can help evaporate the source water in evaporator 6060.

[0281] As shown, the product storage unit 6012 can be attached to and communicate with the volume of the condenser 6076. The product storage unit 6012 may include a product level sensor 6078 that communicates with the controller 6034. The product level sensor 6012 can be used to determine the volume of usable product water and to confirm that fluid is flowing out of the product storage unit 6012. The product storage unit 6012 can be positioned such that it is at the same height as a portion of the condenser 6076. Therefore, the product level sensor 6078 can measure the water level in the product storage unit 6012 and the water level in the condenser 6076. This allows for the estimation of the total usable volume of product water. The product storage unit 6012 can be configured such that the product level sensor 6078 can measure usable product levels up to 1L to 10L (e.g., 1L, 2L, 5L, or 6L), but any volume range is possible. In this sense, the product storage unit 6012 can serve as an auxiliary product storage unit.

[0282] When the product level sensor 6078 measures the level of condensate within the condenser 6076, the condenser can be divided into two sections. The first section can be a condensation section. The second section can be a condensate accumulation section. The volume of the second section can be equal to the maximum available product level to be measured. When the second section is not full, the unfilled portion of the second section can function similarly to the first section, providing a condensation surface for high-pressure steam to condense on. The product storage section 6012 can be fluidly connected to the condensate accumulation section adjacent to the condensate accumulation surface, where condensate first begins to accumulate (e.g., at the bottom of the condenser 6076). This allows the product level sensor 6078 to begin measuring an accurate amount of available product water immediately after accumulation begins in the process flow.

[0283] The product storage unit 6012 may also be connected to the feed pump 6080. The feed pump 6080 can pump fluid from the product storage unit to the compressor 6064. This fluid can be used as a coolant for the compressor 6064 and as a lubricating fluid for one or more bearings of the compressor 6064. Since the bearing feed may be a source of purified water, a return path may not be included. Instead, the fluid can enter the compressor 6064 after use and return to the condenser 6076 without compromising its purity. The pressure and temperature of the bearing feed fluid can be monitored by a bearing feed pressure sensor 6081 and a bearing feed temperature sensor 6083, which communicate data with the controller 6034, respectively.

[0284] After exiting storage sections 6012 and 6014, the product and discharge process flows can flow to their respective heat exchangers 6008A and 6008B. Regarding the product process flow, after passing through product heat exchanger 6008A, the flow can pass through a plurality of sensors 6082A to 6082D downstream of product heat exchanger 6008A. These sensors 6082A to 6082D can sense various characteristics of interest in the product flow. The characteristics of interest can be any of those mentioned herein; however, in certain embodiments, sensors 6082A to 6082D may include first and second conductivity sensors and first and second temperature sensors. In some embodiments, one or more of sensors 6082A to 6082D may be included together as part of a sensor assembly. Controller 6034 can monitor the data generated by sensors 6082A to 6082D to determine how to route the product flow. If the product water meets the quality requirements of medical system 6004 (e.g., within a predetermined temperature range and below a predetermined conductivity threshold), point valve 6086 can be actuated to allow product flow into medical system 6004. A medical system check valve 6088 may be included to ensure that the flow is unidirectional.

[0285] If the quality of the product stream conflicts with at least one requirement of medical system 6004, controller 6034 may actuate diversion valve 6084. When diversion valve 6084 is actuated, it establishes a flow path to discharge point 6018, where the process flow will be abandoned. A discharge check valve 6090 may be included to ensure that flow from system 6000 to discharge point 6018 is unidirectional.

[0286] The discharge flow can also be directed to the discharge point 6018. However, before reaching the discharge point 6018, the discharge flow can be directed to the mixing storage section 6092 via the check valve 6097. As shown, the discharge storage section outlet valve 6094 can selectively direct the cooled discharge flow to the mixing storage section 6092 from the discharge heat exchanger 6008B. The discharge temperature sensor 6096, which can communicate with the controller 6034, can monitor the temperature of the discharge entering the mixing storage section 6092. The mixing storage section 6092 can also be selectively connected to the condenser 6076 via an exhaust valve 6098 actuated by the controller 6034. The exhaust valve 6098 can be periodically actuated to discharge steam, volatiles, air, or other non-condensable gases from the condenser 6076 to maintain optimal operation of the water purifier 6010. The exhaust line may include a vacuum circuit breaker 6099 to prevent a vacuum from forming within the purifier 6010 when it cools (e.g., after use) and its internal pressure decreases. Within the mixing and storage section 6092, the discharged gas can be combined with a relatively low-temperature discharge process flow to cool and condense the discharged gas. Therefore, hot gas can be safely discharged from the condenser 6076 as needed.

[0287] If needed, the source diversion valve 6100, operated by controller 6034, can be opened to allow source water to enter the mixing storage section 6092 for further cooling. Actuation of the source diversion valve 6100 can be based at least in part on the temperature of the discharge flow, as determined by data provided by the discharge temperature sensor 6096. Additionally or alternatively, actuation of the source diversion valve 6100 can be based at least in part on the discharge volume or duty cycle of the vent valve 6098 and / or the temperature of the electronic component housing 6046. The source diversion valve 6100 can also be actuated to the open state by controller 6034 when there is a sufficient supply of source water to the water purifier 6010. The source diversion valve 6100 can also be used to flush filter elements 6006A, 6006B prior to sampling. If the temperature sensor 6048 indicates that the temperature of the electronic component housing 6046 exceeds a predetermined threshold standard, the source diversion valve 6100 can also allow the rapid flow of source fluid to cool the electronic component housing 6046.

[0288] The components of system 6000, which operate at high temperatures, can be divided into a hot section housing 6102 of system 6000. This section can be insulated, as described elsewhere herein, to improve the efficiency of system 6000. A leak sensor 6104 can be included in the hot section 6102 to monitor the integrity of system 6000 and provide data to controller 6034. The leak sensor 6104 may include a conductivity sensor that monitors the presence of liquid in the hot section 6102. Alternatively, the leak sensor may be an optical sensor that monitors a drip tray or similar storage section.

[0289] Now for reference Figure 3 An exemplary block diagram of system 6000 is depicted. (Compared to...) Figure 2 compared to, Figure 3 System 6000 contains many differences. As shown, Figure 3 System 6000 includes an evaporator reservoir 6015, which is in fluid communication with and located outside the evaporator 6060. The evaporator reservoir 6015 may include an evaporator level sensor 6073 that communicates data with the controller 6034. The evaporator level sensor 6012 can be used to determine the volume of water contained within the evaporator and to confirm fluid inflow into the evaporator 6060. The evaporator reservoir 6015 may be positioned at the same height as a portion of the evaporator 6060. Therefore, the evaporator level sensor 6073 can measure the water level within the evaporator reservoir 6015 and the water level within the evaporator 6060. These values ​​can be used to assist in notifying the filling of the evaporator 6060 during startup or at other times before the water level reaches the discharge reservoir 6012. These values ​​can also be used as input variables for various control loops of the purifier 6010 operating on the controller 6034 during the production of the product stream.

[0290] System 6000 may also include an air filter 6093. The air filter may be a HEPA air filter or an air filter with a pore size of 0.2 micrometers or smaller. The air filter may be connected in series with a check valve 6095 leading to a vacuum circuit breaker 6099 of purifier 6010. During operation of the vacuum circuit breaker 6099, the filter can act as a preventative measure against the entry of debris or microorganisms. System 6000 may also include an overpressure relief valve 6091, which can open to release pressure from purifier 6010 if the pressure in purifier 6010 rises above a predetermined value. Depending on the embodiment, the pressure relief valve 6091 may be purely mechanical or controlled by a controller 6034.

[0291] Figure 3The example system shown also includes a single discharge point 6018. A diversion valve 6084 can select a flow path leading to a mixing tank 6092. When product water needs to be sent to the discharge point 6018 (e.g., when sensing criteria are not met or too much product water has accumulated in the condenser 6076), the diversion valve 6084 can be actuated to open that flow path. In some embodiments, a controller 6034 can control the target product level in the product storage section 6014 or the condenser 6076. The discarded product can then flow through a check valve 6085 to the mixing tank 6092. Once the fluid in the mixing tank 6092 has been combined with all other waste or discarded process streams, it can continue to the discharge point 6018.

[0292] The tubing leading to medical system 6004 can be insulated, as indicated by wide, thick wire. This helps prevent and dissipate heat as fluid travels from sensors 6082A to 6082D to medical system 6004. In some embodiments where water can be supplied to medical system 6004 at high temperatures, insulation prevents the user from contacting the hot tubing. Any suitable insulation can be used.

[0293] Now for reference Figure 4 Another exemplary block diagram of system 6000 is shown. In the example diagram, a third heat exchanger 6008C is shown. This heat exchanger 6008C can be a counter-current heat exchanger similar to other heat exchangers described herein. The exemplary third heat exchanger can exchange heat between the source fluid for the purifier and the heat output stream from medical system 6004. In some embodiments, the heat output stream from medical system 6004 can be a waste stream from medical system 6004. For example, the third heat exchanger 6008C can receive used dialysate or effluent from a hemodialysis or peritoneal dialysis device. Such a third heat exchanger 6008C can help improve efficiency and facilitate temperature control of various process streams of system 6000, where the heat output stream from medical system 6004 is available.

[0294] A third heat exchanger 6008C is positioned between at least one filter 6006 and the first heat exchanger 6008A and the second heat exchanger 6008B. Filtered source fluid exiting the at least one filter may pass through the third heat exchanger 6008C before reaching the first heat exchanger 6008A and the second heat exchanger 6008B. Alternatively, the third heat exchanger 6008C may be positioned between the at least one filter 6006 and only one of the first heat exchanger 6008A and the second heat exchanger 6008B (e.g., product water heat exchanger 6008A). The third heat exchanger 6008C may also be included as an optional fluid path for source fluid flowing through the system 6000. In such embodiments, the system 6000 may include branch fluid paths selected by one or more branch valves. When needed, one or more valves may be actuated to establish a source fluid flow to the third heat exchanger 6008C, or to direct the source fluid flow through separate fluid paths to the first and second heat exchangers. For example, a branch valve can be actuated based on a control loop to establish and interrupt the flow path for the source fluid through the third heat exchanger 6008C. The third heat exchanger 6008C can also be positioned between the product heat exchanger 6008A and the medical system 6004 or sensor assembly 6016 (with or without a branch fluid path with a valve).

[0295] The third heat exchanger 6008C can be arranged to transfer heat from the heat output of the medical system 6004 to the source fluid en route to the purifier 6010. In the example where the purifier 6010 is a distillation apparatus, this can help reduce the additional energy required to induce a phase change in the source fluid. Alternatively, with the third heat exchanger 6008C located between the product heat exchanger 6008A and the sensor assembly 6016, the output of the medical system 6004 can assist in heating or cooling the product process stream based on the temperature difference between the two fluids. In the illustrated example, the heat output of the medical system 6004 is directed to the waste or discharge destination 6018 in the example embodiment. In other embodiments, the third heat exchanger 6008C can also serve as a cooler for the medical system 6004. In some embodiments, the medical system 6004 can recirculate fluid through the third heat exchanger 6008C to exchange heat with the relatively cooler source fluid stream. This may be desirable, for example, if the product process stream supplied to the medical system 6004 is too hot for a particular operation. After the heat transfer in the third heat exchanger 6008C, whether the output from the medical system 6004 is recirculated back to the medical system 6004 or discharged to the discharge destination 6018 can be controlled by one or more valves.

[0296] Still referencing Figure 4A bypass valve 6009 is included on one of the first heat exchanger 6008A and the second heat exchanger 6008B. This bypass valve 6009 can be used to provide additional cooling to the process flow as one or more process flows from the purifier 6010 pass through the heat exchangers 6008A and 6008B. In an example embodiment, the bypass valve 6009 is included at the source water output of the product heat exchanger 6008A. The bypass valve 6009 can allow the source fluid leaving the product heat exchanger 6008A to be directly diverted to the discharge destination 6018, as shown. This bypass valve 6009 can be used when overcooling of the product process flow may be required. The bypass valve 6009 can be actuated to a diversion state, and the duty cycle of at least one of the valves controlling the flow of source water through the first heat exchanger 6008A and the second heat exchanger 6008B can be changed (e.g., increased to 90% to 100%). Therefore, relatively cold source water can be rapidly passed through the product heat exchanger 6008A to quickly extract heat from the product process stream, assisting in reducing the product process stream to the target temperature. If the source fluid volume exceeds the demand from the purifier 6010, this large volume of rapidly flowing source water can be discharged to the discharge destination via the bypass valve 6009. When the controller 6034 (e.g., see...) Figure 2 When at least one process variable is determined to be outside a predetermined threshold, the bypass valve 6009 can be actuated to a diversion state. The at least one process variable may be the relationship between the condensate temperature downstream of the condensate heat exchanger 6008A and the source fluid temperature, or may be partially defined by the condensate temperature downstream of the condensate heat exchanger 6008A and the source fluid temperature.

[0297] On the other hand, if the temperature of the process flow leaving the first or second heat exchanger 6008A, 6008B is too low, the controller 6034 of system 6000 (see, for example) Figure 2 The system can command at least partially draw source fluid from alternative fluid source 6003. Alternative fluid source 6003 can be temperature-controlled and can be a hot water source. The hot water source can be a domestic hot water heater or storage unit, a heating storage unit component of system 6000, or any other suitable hot water source. In the example shown, only the first fluid source and the second, alternative fluid source are shown; however, in other embodiments, more than one alternative fluid source 6003 may be present. The first fluid source may be associated with a first set of fluid inlet valves, and the second fluid source may be associated with a second set of fluid inlet valves, which includes at least one valve not in the first set of inlet valves.

[0298] By at least partially drawing source fluid from alternative fluid source 6003, the temperature drop of the process flow from purifier 6010 can be reduced as it passes through first heat exchanger 6008A and second heat exchanger 6008B. Additionally, fluid can be drawn from alternative fluid source 6003 if a process variable violates a predetermined threshold. For example, if the heating element 6054 duty cycle is exceeded, the source valve commands duty cycle 6432 (see, for example, [link to relevant documentation]). Figures 100 to 101C If the speed of the compressor 6072 exceeds a predetermined threshold, fluid can be drawn from the alternative fluid source 6003. This can help allow the purifier 6010 to purify more fluid in the same amount of time, or can help minimize the demand on various components of the purifier 6010, such as the heating element 6054 or the compressor 6072.

[0299] Now for reference Figure 5 , showed Figure 1 An exemplary embodiment of the system 6000 is shown. For clarity, in Figure 5 Only the fluid line 6126 carrying source water is shown. Source water can enter system 6000 at connector 6120. A manual shut-off valve 6032 may be included to prevent source water from flowing into system 6000. Source water can flow through multiple filters 6006A, 6006B. In the example shown, these filters may be 5L activated carbon filters. A user-operated sample port 6038 is included between filters 6006A, 6006B. In this example, sample port 6038 includes a manually actuated ball valve. Pre- and post-filtration pressure sensors 6036, 6044 may also be included. System 6000 includes a pressure regulator 6040 that controls the source water pressure to a predetermined value (e.g., 20 psig).

[0300] The source water flow can be diverted to facilitate individual distribution of source water to the product and discharge heat exchangers 6008A and 6008B. Along the path to the discharge heat exchanger 6008B, the source water fluid line 6126 can extend to the inlet 6122 of the electronic component heat exchanger. Source water can flow through fluid conduits in the electronic component housing 6046 and exit through the electronic component heat exchanger outlet 6124. Although not shown, the flow conduits in the electronic component housing 6046 can be arranged in a non-linear or tortuous (e.g., zigzag) pattern to help maximize heat transfer. The source water fluid line 6126 extending from the electronic component heat exchanger outlet 6124 provides a fluid path for the source water to the discharge heat exchanger 6008B. If desired, branches can be included in this section of the source water fluid line 6126, allowing the source water flow to be diverted to the mixing storage section 6092. The source water fluid pipeline 6126 can enter the hot section shell 6102 via the product heat exchanger channel 6128 and the discharge heat exchanger channel 6130 in the hot section shell 6102.

[0301] Still referencing Figures 6 to 7 The diagram shows a partial view of system 6000, with the hot section housing 6102 removed. Again, for clarity, only the source water fluid line 6126 is shown, while those lines carrying various process flows are not shown. The source water fluid line 6126 can be connected to the source water inlets 6132A and 6132B of the respective heat exchangers 6008A and 6008B. Source water can flow through heat exchangers 6008A and 6008B to the respective source water outlets 6134A and 6134B. After leaving heat exchangers 6008A and 6008B, the source water flow can be recombined and proceed through source water line 6126 to the storage tank 6052 of water purifier 6010.

[0302] Now also referencing Figure 8 The diagram shows views of exemplary heat exchangers 6008A and 6008B. Heat exchangers 6008A and 6008B can each be arranged as a tubular spiral structure through which source water and various process flows of system 6000 can flow. The spiral structure formed by each heat exchanger 6008A and 6008B can have a substantially constant radius and pitch. Heat exchangers 6008A and 6008B can be arranged concentrically, wherein one of heat exchangers 6008A and 6008B has a smaller radius and is positioned inside the other. Figure 8In the exemplary embodiment shown, the discharge heat exchanger 6008B is positioned inside the product heat exchanger 6008A. The lengths of the fluid paths in the product heat exchanger 6008A and the discharge heat exchanger 6008B can be substantially equal. The pitch of each heat exchanger 6008A, 6008B can be substantially equal. Therefore, the height of the inner or smaller radius heat exchanger 6008B can be greater than the height of the outer heat exchanger 6008A.

[0303] Figure 9 A cross-sectional view of a portion of exemplary heat exchangers 6008A and 6008B is shown. As illustrated, each heat exchanger 6008A and 6008B includes large-diameter source flow conduits 6136A and 6136B forming the outer surface of the heat exchanger 6008A and 6008B. These source flow conduits 6136A and 6136B are shown to have substantially equal diameters; however, in some examples, their diameters may differ, with one being larger than the other.

[0304] Within source flow conduits 6136A and 6136B are conduits carrying process flow from water purifier 6010. Product water heat exchanger 6008A may include at least one product flow conduit 6138 positioned within its source flow conduit 6136A. Each of the at least one product flow conduit 6138 may have equal diameters or may have different diameters. Feed heat exchanger 6008B includes a plurality of internal flow conduits. Figure 9 In a specific example, the discharge heat exchanger includes a discharge flow conduit 6140 and an exhaust flow conduit 6142 within its source flow conduit 6136B. In some embodiments, additional flow conduits may be included. For example, multiple discharge or exhaust conduits 6140, 6142 may be included within the source flow conduit 6136B. In some embodiments, the discharge flow conduit 6140 and exhaust flow conduit 6142 may be positioned side-by-side as shown, or they may be braided or interwoven together. According to this embodiment, the product flow conduit 6138 may similarly be braided or interwoven.

[0305] like Figure 9As best shown, to maximize the compactness of heat exchangers 6008A and 6008B, the pitch of the helical structure of heat exchangers 6008A and 6008B may be relatively shallow. For example, the pitch may be 5%-40% larger than the outer diameter of the source flow conduits 6136A and 6136B. In other embodiments, the pitch may be approximately equal to the outer diameter of the source flow conduits 6136A and 6136B, and each revolution of the helical structure may touch its adjacent revolution. When the source flow conduits 6136A and 6136B are constructed of a thermally conductive material (such as stainless steel or another metal), a pitch larger than the outer diameter of the source flow conduits 6136A and 6136B may be desirable. When the source flow conduits 6136A and 6136B are made of high-temperature silicon or similar materials, the gap between the revolutions may be reduced or omitted. This gap may also be omitted if a material with high thermal conductivity is used.

[0306] Now for reference Figures 10 to 11 This shows another view of the exemplary system 6000. In the source water (in Figure 10 (Displayed as dotted lines) After entering the reservoir 6052, water can begin to fill the plurality of evaporator tubes 6140. The evaporator tubes 6140 extend from the volume of the reservoir 6052 through the condenser 6076 to the volume of the steam chamber 6072. The first tube sheet 6142A and the second tube sheet 6142B may include receiving orifices 6144 for receiving the end of each evaporator tube 6140. The tube sheets 6142A and 6142B can hold the evaporator tubes 6140 within the volume of the condenser 6076 in a generally uniformly spaced manner. The tube sheets 6142A and 6142B may also form seals or include gasket members that form a seal around the end of the evaporator tubes 6140. This seal prevents fluid communication between the evaporator tubes 6140 and the internal volume of the condenser 6076. The condenser 6076 may also include at least one plate 6143 to serve as a baffle for guiding incoming steam to the outer surface of the evaporator tubes 6140. A second tube sheet 6142B may form the bottom wall of the steam chamber 6072. When source water enters the steam chamber 6072, water can accumulate at the bottom of the steam chamber 6072 on top of the second tube sheet 6142B.

[0307] In the example embodiment, fewer than 100 (specifically 96) evaporator tubes 6140 are included. In other embodiments, more or fewer evaporator tubes 6140 may be included. Each evaporator tube 6140 may have substantially the same diameter. The diameter of the evaporator tube 6140 may be between 5% and 10% (e.g., about 6%) of the diameter of the condenser 6072. In some embodiments, the diameters of the evaporator tubes 6140 may not all be equal. At least one or more of the evaporator tubes 6140 may have different diameters.

[0308] In some embodiments, the diameter of the evaporator tubes 6140 may vary depending on their location. For example, the evaporator tubes 6140 in a first section of the evaporator may have a first diameter, while those in a second section may have a second diameter, those in a third section may have a third diameter, and so on. In some embodiments, those evaporator tubes extending through the central region of the condenser 6076 volume may have a first diameter, while those in regions further away from the central region may have a second diameter. Depending on the embodiment, the first diameter may be larger or smaller than the second diameter. In some embodiments, a diameter gradient of the evaporator tubes 6140 may be established based on the evaporator tubes 6140 extending through the central portion of the condenser 6076 volume and those evaporator tubes furthest from the central portion. For example, tubes may include diameters that gradually increase or decrease in size as the distance from the central portion increases.

[0309] The evaporator tube 6140 may occupy between 25% and 50% (e.g., about 37%) of the internal volume of the condenser 6076. The material constituting the evaporator tube 6140 may vary depending on the embodiment; however, a material with high thermal conductivity may be used. The material used may be any material described elsewhere herein.

[0310] In some embodiments, the evaporator tubes 6140 may be made of the same or similar material as that used to construct the tube sheets 6142A, 6142B. Both the evaporator tubes 6140 and the tube sheets 6142A, 6142B may be metallic materials with high thermal conductivity. Stainless steel may be used in some examples. The evaporator tubes 6140 may be welded, brazed, or otherwise joined to the tube sheets 6142A, 6142B. This allows for a reduction in the overall size of the purifier 6010 compared to embodiments in which the tube sheets are constructed of an elastic material such as ethylene propylene diene monomer (EPDM) rubber. At welded, brazed, or similar attachments, the joints between the tube sheets 6142A, 6142B and the individual evaporator tubes 6140 may also form a fluid-impermeable seal. Thus, the tube sheets 6142A, 6142B can be thinned while still maintaining a strong seal between the condenser 6076 volume and the reservoir 6052 / steam chamber 6072.

[0311] Although not shown in this embodiment, the evaporator tube 6140 may include a packing element (e.g., see...). Figure 62 Such as rods that fill a portion of the cross-sectional area of ​​each (or possibly only some) of the evaporator tubes 6140. This can cause a thin layer or film of source fluid to exist between the outside of the packing element and the inner surface of the evaporator tubes 6140 in which the packing element is disposed.

[0312] Now for reference Figures 12 to 16 When heat from heating element 6054 (e.g., see...) Figure 2 When the condensed steam in condenser 6076 evaporates the source water, a discharge process stream or concentrate can be generated. The discharge process stream can fill a portion of the volume of steam chamber 6072. As shown, a discharge or concentrate storage section 6014 can be attached to the side of steam chamber 6072. Obstacle 6146 ( Figure 13 (Best shown in the diagram) A portion of the inflow path 6148 from the steam chamber 6072 to the discharge storage section 6014 may be included therein or defined. For example, the inflow path 6148 may include a first portion 6333 and a second portion 6335. The second portion may be defined at least partially by a barrier 6146. The barrier 6146 may be a weir or similar barrier that shields a portion of the discharge storage section 6014. The barrier 6146 can substantially prevent liquid instability in the shielded portion 6334 caused by splashing and other vigorous liquid movement due to boiling in the steam chamber 6072. A portion of the inflow path 6148 may be disposed within the internal volume of the discharge storage section 6014.

[0313] The obstruction 6146 shown includes a plate integral with the wall of the inflow path 6148 and opposite the inflow port 6336 from the steam chamber 6072. The plate also extends downward at a transverse angle to the first portion 6333 of the inflow path 6148 into the discharge storage section 6012. This section can prevent splashing and other interference from entering the shielded section 6334 from the unshielded section 6337. As shown, an exhaust path 6338 may also be included to allow gas displaced by the incoming discharge or gas generated by evaporation to exit the discharge storage section 6012. The exhaust path 6338 may be substantially parallel to and extend above the first portion 6333 of the inflow path 6148 (relative to gravity). In an example embodiment, the exhaust path 6338 may lead to the steam chamber 6072. The exhaust path 6338 may have a smaller cross-sectional area than the first portion 6333 of the inflow path 6148. The wall of the steam chamber 6072 may include an exhaust port 6152, and the exhaust port 6152 may establish fluid communication between the exhaust path 6338 and the steam chamber 6072. The cross-sectional area of ​​the exhaust port 6152 may be smaller than the cross-sectional area of ​​the exhaust path 6338.

[0314] As mentioned above, the liquid level within the discharge reservoir 6014 can be sensed by the discharge level sensor 6074. Any suitable sensor for measuring the liquid level within the discharge reservoir 6014 can be used; however, a float-type sensor similar to that described elsewhere herein is shown. The discharge level sensor 6074 may include a float assembly comprising a float 6154 attached to an arm 6156. In this example, the float 6154 is shown as a hollow structure attached to the end of the arm 6156. In other embodiments, the float 6154 may be solid and made of a heat- and corrosion-resistant, easily buoyant material. The arm 6156 may be coupled to a pivot 6158. Preferably, the discharge level sensor 6074 may be disposed within a shielding portion 6334.

[0315] As the liquid level changes within the discharge storage section 6014, the position of the float 6154 can rise and fall in the same manner within the float sweep range. When the float 6154 is attached to the arm 6156, the arm 6156 can pivot about the pivot 6158. The discharge level sensor 6074 may include a Hall effect sensor 6160, which is referred to here primarily. Figure 16 The Hall effect sensor 6160 monitors the position of at least one magnet 6155, which shifts with changes in the liquid level. The at least one magnet 6155 may be located, for example, on a float 6154 or an arm 6156. In the example shown, two magnets 6155 may be mounted adjacent to the pivot 6158. The discharge storage section 6014 may be configured to allow the discharge level sensor 6074 to directly measure the liquid level in the steam chamber 6072, at least when the purifier 6010 is in certain states (e.g., startup). The sweep range or displacement range of the float 6154 may be selected such that the float 6154 rises with the liquid level in the steam chamber 6072. Although the described embodiment uses the Hall effect sensor 6160, other types of sensors may be used. For example, some embodiments may include a rotary encoder or potentiometer instead of a Hall effect sensor, or may include a rotary encoder or potentiometer in addition to a Hall effect sensor.

[0316] The sweep range of the float assembly can be selected such that it includes points where the liquid levels in all steam chambers are expected to be at equal height during at least some operating states of the purifier 6010 (e.g., startup). Therefore, the discharge level sensor 6074 can be a direct level sensor that directly measures the level of the concentrate within the steam chamber 6072 to which the discharge storage section 6014 is attached (if it is within the expected range).

[0317] In some embodiments, the liquid level can be sensed less directly when the purifier 6010 generates the purified liquid. For example, the discharge level sensor 6074 may have a sweep range that includes a point above the expected range of the liquid level in the steam chamber 6072. Turbulent boiling action occurring in the steam chamber 6072 may occasionally cause liquid to splash into the discharge level sensor 6074 to fill it. Controller 6034 (see, for example, Figure 2 The accumulation rate of the discharged material can be analyzed to determine whether the liquid level in the steam chamber 6072 is within the expected range. If the rate exceeds the limit, it can be determined whether the liquid level in the steam chamber 6072 needs adjustment or is abnormal.

[0318] Now for reference Figure 17 A perspective view of the purifier 6010 and the discharge storage section 6014 is shown. For clarity, in... Figure 17 Only the discharge flow conduit is shown. As shown, the discharge storage section 6014 can be attached to the discharge flow conduit 6162, which serves as the outlet of the discharge storage section. The outlet can establish a flow path from the discharge storage section 6014 to the discharge heat exchanger 6008B. A discharge storage valve 6356 may also be included (see, for example, see...). Figures 42 to 43 This is to control the purging of the discharge process flow from purifier 6010. The discharge storage valve 6356 can be controlled by controller 6034 (e.g., see...). Figure 2 The system operates to maintain the liquid level in the steam chamber 6072 within a desired range. Data from the discharge level sensor 6074 can be ...

Claims

1. A distillation apparatus, comprising: A source fluid input, wherein the source fluid input is selectively fluidly connected to a source via a fluid input valve assembly; An evaporator is in fluid communication with the source fluid input and with a compressor having an impeller operatively coupled to an impeller motor. The evaporator is configured to convert the source fluid from the source fluid input into a vapor stream and a concentrated stream as the source fluid travels toward the compressor. A condenser that is in heat transfer relationship with a plurality of outer surfaces of the evaporator, the condenser being configured to condense the high-pressure steam flow from the compressor by bringing the high-pressure steam flow into contact with the plurality of outer surfaces of the evaporator; A concentrate level sensor is configured to sense the current concentrate level in a concentrate storage section having an inflow path disposed above the evaporator and having a long axis extending parallel to the evaporator. as well as At least one controller is configured to control the rotational speed of the impeller in both the low-temperature distillate production state and the high-temperature distillate production state by periodically generating impeller motor commands based on a rated low-temperature distillate production speed command in a low-temperature distillate production state and a rated high-temperature distillate production speed command in a high-temperature distillate production state, wherein the rated low-temperature distillate production speed command is a motor speed command that is faster than the rated high-temperature distillate production speed command. Specifically, the impeller motor commands are adjusted based on data signals from the concentrate level sensor indicating the level of concentrate in the concentrate storage section. Wherein, when the data signal indicates that the level of concentrated material in the concentrated material storage section is greater than a first threshold, the impeller motor command decreases, or When the data signal indicates that the level of the concentrated material in the concentrated storage section is greater than a first threshold, the impeller motor command is maintained at a value no greater than the previous impeller motor command value.

2. The distillation apparatus according to claim 1, wherein, The adjustment is limited by the impeller motor command increment limit.

3. The distillation apparatus according to claim 2, wherein, The limit for the impeller motor command increment is ≤10 rpm / sec.

4. The distillation apparatus according to claim 2, wherein, The limit for the impeller motor command increment is ≤5 rpm / sec.

5. The distillation apparatus according to claim 1, wherein, The first threshold is defined as the following concentrate level, at which the concentrate storage section is at a predetermined fill value between 65% and 80% of its full value.

6. The distillation apparatus according to claim 1, wherein, When the data signal indicates that the level of the concentrated material in the concentrated material storage section is greater than the second threshold, the impeller motor command is increased.

7. The distillation apparatus according to claim 1, wherein, The rated speed command for producing high-temperature distillate is a calibration value defined during manufacturing.

8. The distillation apparatus according to claim 1, wherein, The rated production rate for high-temperature distillate is less than 80% of the rated production rate for low-temperature distillate.

9. The distillation apparatus according to claim 1, wherein, The rated production rate for high-temperature distillate is greater than 45% of the rated production rate for low-temperature distillate.

10. The distillation apparatus according to claim 1, wherein, The rated speed for producing the cryogenic distillate is 4500 rpm.

11. The distillation apparatus according to claim 1, wherein, The rated speed for producing the cryogenic distillate is 5000 rpm.

12. A method for controlling a compressor of a distillation apparatus, the method comprising: Open at least one fluid inlet valve to deliver source fluid from the fluid source to the storage tank of the distillation apparatus; The source fluid is converted into a concentrated stream and a vapor stream in the evaporator; The processor determines a state-specific compressor speed command, which is based on a rated speed command for low-temperature distillate production in a low-temperature distillate production state and a rated speed command for high-temperature distillate production in a high-temperature distillate production state, wherein the rated speed command for low-temperature distillate production is a motor speed command that is faster than the rated speed command for high-temperature distillate production. The processor generates the final command speed based on the compressor speed command; The processor commands the compressor impeller to rotate at the final commanded speed; The steam stream is compressed via the compressor; and The steam stream is condensed into condensate, and as the steam stream condenses, heat is transferred to the evaporator. The method further includes using a level sensor to sense the level of concentrated material in a concentrated material storage section that is in fluid communication with the evaporator. The generation of the final command speed includes adjusting the compressor speed command based on the concentrated material level. The adjustment includes: when the concentrated material level is greater than a first threshold, reducing the compressor speed command, or The adjustment includes: when the concentration material level is greater than the first threshold, maintaining the final command speed at a level not greater than the final command speed of the previous command.

13. The method according to claim 12, wherein, The first threshold is defined as the following concentrate level, at which the concentrate storage section is at a predetermined fill value between 65% and 80% of its full value.

14. The method according to claim 12, wherein, The adjustment includes a command to reduce the compressor speed when the concentrated material level is greater than a second threshold.

15. The method according to claim 12, wherein, Generating the final command speed includes determining the adjustment of the compressor speed command.

16. The method according to claim 15, wherein, The adjustment is limited by the incremental limit.

17. The method according to claim 16, wherein, The incremental limit is ≤10 rpm / sec.

18. The method according to claim 16, wherein, The incremental limit is ≤5 rpm / sec.

19. The method according to claim 12, wherein, The rated speed command for producing high-temperature distillate is a calibration value defined during manufacturing.

20. The method according to claim 12, wherein, The rated production rate for high-temperature distillate is less than 80% of the rated production rate for low-temperature distillate.

21. The method according to claim 12, wherein, The rated production rate for high-temperature distillate is greater than 45% of the rated production rate for low-temperature distillate.

22. The method according to claim 12, wherein, The rated speed for producing the cryogenic distillate is 4500 rpm.

23. The method according to claim 12, wherein, The rated speed for producing the cryogenic distillate is 5000 rpm.

Images