Steam distillation device, method and system

Abstract

To provide a steam distillation system for producing clean water by purifying water.SOLUTION: A fluid steam distillation system is provided, the system comprises: a control system for controlling the fluid steam distillation device, the control system comprising, a release valve, a raw material flow controller for controlling a raw material flow rate valve, and a discharge level sensor connected to the release controller and the raw material flow rate controller. The discharge level sensor transmits a signal related to a discharge level to the discharge controller and the raw material flow rate controller which indicates the discharge level, the raw material flow rate controller drives the raw material flow rate valve on the basis of at least the discharge level sensor signal. The discharge controller drives the discharge valve on the basis of at least the discharge level sensor signal, and the discharge level and the raw material flow rate level are held by using the discharge level sensor signal as input.SELECTED DRAWING: Figure 75

Description

[Technical Field]

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

[0002] Reliable sources of clean water are difficult to obtain for the majority of humanity. For example, the Canadian International Development Agency reports that approximately 1.2 billion people lack access to safe drinking water. The report attributes millions of deaths each year, most of them children, to water-related diseases. Many water purification technologies are known, including carbon filters, chlorination, pasteurization, and reverse osmosis. Many of these technologies are significantly affected by variations in water quality and do not address the wide variety of common contaminants, such as bacteria, viruses, organic matter, arsenic, lead, mercury, and pesticides, that may be found in water supplies in the developing world. Some of these systems require the use of consumables, such as filters or chemicals. Furthermore, some of these technologies are only suitable for centralized, large-scale water systems, requiring both significant infrastructure and highly trained operators. The ability to produce reliable clean water, regardless of source, on a smaller, decentralized scale, without the need for consumables and constant maintenance, is highly desirable, especially in the developing world. Summary of the Invention [Problem to be solved by the invention]

[0003] The use of vapor compression distillation to purify water is well known and may address many of these concerns. However, scarce financial resources, limited technological assets, and low population densities that make it unfeasible to build centralized, large-scale water systems in much of the developing world also limit the availability of sufficient affordable and reliable electricity to operate vapor compression distillation systems and hinder the ability to properly maintain such systems. In such situations, improved vapor compression distillation systems and related components can provide a solution, increasing efficiency and production capacity while reducing the power costs required to operate the system and the amount of system maintenance required. [Means for solving the problem]

[0004] In accordance with one aspect of the present invention, a fluid vapor distillation system is disclosed, the system including a control system for controlling a fluid vapor distillation apparatus, the system including a discharge controller controlling a discharge valve, a feed flow controller controlling a feed flow valve, and a discharge level sensor connected to the discharge controller and the feed flow controller, the discharge level sensor sending signals related to the discharge level to the discharge controller and the feed flow controller indicating the discharge level, the feed flow controller driving the feed flow valve based on at least the discharge level sensor signal, the discharge controller driving the discharge valve based on at least the discharge level sensor signal, and the discharge level and the feed flow level being maintained using the discharge level sensor signal as an input.

[0005] In some embodiments of this aspect of the invention, the control system includes at least one controller and includes one or more of an idle state in which the at least one controller is not operating, an injection state in which a feed valve is opened and feed fluid enters the sump of the fluid vapor distillation apparatus, a heating state in which a heater in the sump is at full power until the fluid in the sump reaches a predetermined temperature, a heat exchanger full state in which the feed valve is opened to a predetermined duty cycle, a start pump state in which a bearing feed pump is driven at a predetermined speed and a discharge motor is started, and a run state in which the fluid vapor distillation apparatus produces product water. The system also includes a feed fluid inlet, an evaporator-condenser device having a substantially cylindrical housing, and a plurality of tubes within the housing. The feed fluid inlet is fluidly connected to the evaporator-condenser, which converts the feed fluid into vapor and the compressed vapor into a product fluid. A heat exchanger is fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger including an outer tube and at least one inner tube. A regenerative blower is fluidly connected to the evaporator-condenser, which compresses the vapor, which flows to the evaporator-condenser, where the compressed vapor is converted into a product fluid. The heat exchanger is disposed around the evaporator-condenser housing. The outer tube included in the heat exchanger is a feed fluid flow path, and the at least one inner tube is a product fluid flow path. The heat exchanger further includes at least three inner tubes, which are twisted together to form a substantially helical shape. The heat exchanger includes two ends, each with a connector attached thereto, the connectors forming a joint with the evaporator-condenser. The evaporator-condenser tubes further include packing inside the tubes. The packing is rods. The evaporator-condenser further includes a vapor chamber fluidly connected to the plurality of tubes. The regenerative blower further includes an impeller assembly driven by a magnetic drive coupling. The control system includes at least two processors: a motor control engine processor and an ARM® processor. The fluid vapor distillation apparatus further includes a conductivity meter and a conductivity cell for measuring the conductivity of the product fluid.

[0006] In another aspect of the present invention, a fluid vapor distillation apparatus is disclosed, the apparatus including a feed fluid inlet, an evaporator-condenser apparatus having a substantially cylindrical housing, and a plurality of tubes in the housing, the feed fluid inlet fluidly connected to the evaporator-condenser, the evaporator-condenser converting the feed fluid to vapor and converting the compressed vapor to a product fluid, a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger including an outer tube and at least one inner tube, a regenerative blower fluidly connected to the evaporator-condenser, the regenerative blower compressing the vapor, the compressed vapor flowing to the evaporator-condenser, and the compressed vapor being converted to a product fluid, and a control system for controlling the fluid vapor distillation apparatus. a discharge controller controlling the discharge valve, a feedstock flow controller controlling the feedstock flow valve, and a discharge level sensor in communication with the discharge controller and the feedstock flow controller, wherein the discharge level sensor sends a signal to the discharge controller and the feedstock flow controller indicating the discharge level, the feedstock flow controller driving the feedstock flow valve based on at least the signal of the discharge level sensor, and the discharge controller driving the discharge valve based on at least the signal of the discharge level sensor, whereby the discharge level and the feedstock flow level are maintained using the signal of the discharge level sensor as an input.

[0007] Some embodiments of this aspect of the invention include at least one controller, an idle state in which the at least one controller is not operating, an injection state in which a feed valve is opened and feed fluid enters a sump of the fluid vapor distillation apparatus, a heating state in which a heater in the sump is at maximum output until the fluid in the sump reaches a predetermined temperature, a heat exchanger peak state in which the feed valve is opened and set to a predetermined duty cycle, a start pump state in which a bearing feed pump is driven at a predetermined speed and a discharge motor is activated, and an operating state in which the fluid vapor distillation apparatus produces product water. The heat exchanger is disposed around the evaporator-condenser housing. The heat exchanger includes an outer tube for the feed fluid flow path and at least one inner tube for the product fluid flow path. The heat exchanger further includes at least three inner tubes, which are twisted together to form a substantially helical shape. The heat exchanger includes two ends, each with a connector attached thereto, which forms a joint with the evaporator-condenser. The evaporator-condenser tubes further include packing inside the tubes, which is rod packing. The evaporator-condenser further includes a vapor chamber fluidly connected to the plurality of tubes. The regenerative blower further includes an impeller assembly driven by a magnetic drive linkage. The control system includes at least two processors: a motor control engine processor and an ARM® processor. The fluid vapor distillation apparatus further includes a conductivity meter and a conductivity cell for measuring the conductivity of the product fluid.

[0008] In accordance with one aspect of the present invention, a fluid vapor distillation apparatus is disclosed, the apparatus including a feed fluid inlet, an evaporator-condenser apparatus having a substantially cylindrical housing, and a plurality of tubes within the housing, the feed fluid inlet fluidly connected to the evaporator-condenser, the evaporator-condenser converting the feed fluid into vapor and converting the compressed vapor into a product fluid, a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger including an outer tube and at least one inner tube, a regenerative blower fluidly connected to the evaporator-condenser, the regenerative blower compressing the vapor, the compressed vapor flowing to the evaporator-condenser, the compressed vapor being converted into a product fluid, and the apparatus also including a control system for controlling the fluid vapor distillation apparatus.

[0009] Some embodiments of this aspect of the invention include one or more of the following: The control system includes a discharge controller controlling a discharge valve, a feed flow controller controlling a feed valve, and a discharge level sensor in communication with the discharge controller and the feed flow controller, wherein the discharge level sensor sends a signal related to the discharge level to the discharge controller and the feed flow controller indicating the discharge level, the feed flow controller drives the feed valve based on at least the signal from the discharge level sensor, and the discharge controller drives the discharge valve based on at least the signal from the discharge level sensor, thereby maintaining the discharge level and the feed flow level using the signal from the discharge level sensor as an input. The control system includes at least one controller, and includes an idle state in which the at least one controller is not operating, an injection state in which the feed valve is opened and the feed fluid enters the sump of the fluid vapor distillation apparatus, a heating state in which the sump heater is at maximum output until the fluid in the sump reaches a predetermined temperature, a heat exchanger peak state in which the feed valve is opened and a predetermined duty cycle is set, a start pump state in which the bearing feed pump is driven at a predetermined speed and the discharge motor is started, and an operating state in which the fluid vapor distillation apparatus produces product water. The heat exchanger is disposed around the evaporator / condenser housing. The heat exchanger includes an outer tube serving as a feed fluid flow path and at least one inner tube serving as a product fluid flow path. The heat exchanger further includes at least three inner tubes. The at least three inner tubes are twisted together to form a substantially helical shape. The heat exchanger further includes two ends, each end having a connector attached thereto, the connector forming a joint with the evaporator-condenser. The evaporator-condenser tubes further include packing inside the tubes. The packing is rods. The evaporator-condenser further includes a vapor chamber fluidly connected to the plurality of tubes. The regenerative blower further includes an impeller assembly driven by a magnetic drive coupling. The control system includes at least two processors, namely, a motor control engine processor and an ARM® processor. The fluid vapor distillation apparatus further includes a conductivity meter and a conductivity cell for measuring the conductivity of the product fluid.

[0010] In accordance with one aspect of the present invention, a steam distillation system is disclosed, the system including a steam distillation apparatus including a feed fluid inlet, an evaporator-condenser apparatus including a substantially cylindrical housing, and a plurality of tubes in the housing, the feed fluid inlet fluidly connected to the evaporator-condenser, which converts the feed fluid into vapor and the compressed vapor into a product fluid, the system further including a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger including an outer tube and at least one inner tube, and the system including a regenerative blower fluidly connected to the evaporator-condenser, which compresses the vapor, the compressed vapor flows to the evaporator-condenser, and the compressed vapor is converted into the product fluid, the system also including a control system for controlling the steam distillation apparatus, and a Stirling engine electrically connected to the steam distillation apparatus, the Stirling engine at least partially powering the steam distillation apparatus.

[0011] Some embodiments of this aspect of the invention include one or more of the following: the control system includes a discharge controller controlling the discharge valve, a feed flow controller controlling the feed flow valve, and a discharge level sensor in communication with the discharge controller and the feed flow controller, the discharge level sensor sending a signal related to the discharge level to the discharge controller and the feed flow controller indicating the discharge level, the feed flow controller driving the feed flow valve based on at least the signal from the discharge level sensor, and the discharge controller driving the discharge valve based on at least the signal from the discharge level sensor, whereby the discharge level and the feed flow level are maintained using the signal from the discharge level sensor as an input. The system for controlling the apparatus further includes at least one controller, and the system includes an idle state in which the at least one controller is not operating, an inlet state in which the feed valve is opened and feed fluid enters a sump of the fluid steam distillation apparatus, a heating state in which a heater in the sump is at maximum output until the fluid in the sump reaches a predetermined temperature, a heat exchanger peak state in which the feed valve is opened and a predetermined duty cycle is set, a start pump state in which a bearing feed pump is driven at a predetermined speed and a discharge motor is started, and an operating state in which the fluid steam distillation apparatus produces product water. a Stirling engine comprising at least one rocking drive mechanism including a rocking beam having a rocker pivot, at least one cylinder, and at least one piston, wherein a piston is housed in each cylinder and the piston is capable of reciprocating substantially linearly within each cylinder; the Stirling engine further comprises at least one linkage assembly having a proximal end and a distal end, wherein the proximal end is connected to the piston and the distal end is connected to the rocking beam by an end pivot, and linear motion of the piston is converted into rotational motion of the rocking beam; the Stirling engine further comprises a crankcase housing the rocking beam and a first part of the linkage assembly, and a crankshaft connected to the rocking beam by a connecting rod, and wherein rotational motion of the rocking beam is transmitted to the crankshaft; and the Stirling engine further comprises a working space housing the at least one cylinder, the at least one piston, and a second part of the linkage assembly, and a seal for sealing the working space from the crankcase.

[0012] Some embodiments of this implementation of the system include one or more of the following: the seal is a rolling diaphragm, the linkage assembly further includes a piston rod and a link rod, the piston rod and the link rod being connected together by a coupling means, or the system further includes a lubricating fluid pump within the crankcase.

[0013] Various embodiments of the system include one or more of the following: a heat exchanger disposed around the evaporator-condenser housing; an outer tube of the heat exchanger providing a feed fluid flow path and at least one inner tube providing a product fluid flow path; or the heat exchanger further comprising at least three inner tubes.

[0014] In accordance with one aspect of the present invention, a steam distillation apparatus is disclosed, the apparatus including a discharge controller controlling a discharge valve, a feed flow controller controlling a feed flow valve, and a discharge level sensor in communication with the discharge controller and the feed flow controller, the discharge level sensor sending a signal related to the discharge level to the discharge controller and the feed flow controller indicative of the discharge level, the feed flow controller driving the feed flow valve based on at least the discharge level sensor signal, and the discharge controller driving the discharge valve based on at least the discharge level sensor signal, whereby the discharge level and the feed flow level are maintained using the discharge level sensor signal as an input.

[0015] Some embodiments of this aspect of the invention include one or more of the following: the apparatus further includes at least one controller, and the apparatus includes an idle state in which the at least one controller is not operating, an inject state in which a feed valve is opened and feed fluid enters the sump of the fluid vapor distillation apparatus, a heat state in which a heater in the sump is at full power until the fluid in the sump reaches a predetermined temperature, a heat exchanger prime state in which the feed valve is opened to a predetermined duty cycle, a start pump state in which a bearing feed pump is driven at a predetermined speed and a discharge motor is started, and a run state in which the fluid vapor distillation apparatus produces product water. The apparatus includes a feed fluid inlet, an evaporator-condenser apparatus including a substantially cylindrical housing, and a plurality of tubes in the housing, the feed fluid inlet fluidly connected to the evaporator-condenser, which converts the feed fluid into vapor and the compressed vapor into a product fluid, the apparatus further includes a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger including an outer tube and at least one inner tube, and the apparatus includes a regenerative blower fluidly connected to the evaporator-condenser, the regenerative blower compressing the vapor, the compressed vapor flowing to the evaporative condenser, and the compressed vapor being converted into a product fluid. The heat exchanger is disposed around the evaporator-condenser housing. The heat exchanger includes an outer tube that is a feed fluid flow path and at least one inner tube that is a product fluid flow path. The heat exchanger further includes at least three inner tubes, which are twisted together to form a substantially helical shape. Where the heat exchanger includes two ends, each end having a connector attached thereto, the connector forming a joint with the evaporator-condenser; Where the evaporator-condenser tubes further include packing inside the tubes; Where the packing is rods; Where the evaporator-condenser further includes a steam chamber fluidly connected to the plurality of tubes; Where the regenerative blower further includes an impeller assembly driven by a magnetic drive coupling; Where the control system includes at least two processors, namely, a motor control engine processor and an ARM® processor; Where the fluid steam distillation apparatus further includes a conductivity meter and a conductivity cell for measuring the conductivity of the product fluid.

[0016] In accordance with one aspect of the present invention, a water vapor distillation apparatus is disclosed, comprising a control system for controlling the water vapor distillation apparatus, the control system including at least one controller, an idle state in which the at least one controller is not operating, an inject state in which a feed valve is opened and feed fluid enters a sump of the water vapor distillation apparatus, a heat state in which a heater in the sump is at full power until the fluid in the sump reaches a predetermined temperature, a heat exchanger prime state in which the feed valve is opened and a predetermined duty cycle is reached, a start pump state in which a bearing feed pump is driven at a predetermined speed and a discharge motor is started, and an operating state in which the water vapor distillation apparatus produces product water.

[0017] Some embodiments of this aspect of the invention include one or more of the following: the control system further includes a discharge controller controlling the discharge valve, a feed flow controller controlling the feed flow valve, and a discharge level sensor in communication with the discharge controller and the feed flow controller, wherein the discharge level sensor sends a signal to the discharge controller and the feed flow controller indicating the discharge level related to the discharge level, the feed flow controller actuating the feed flow valve based on at least the signal of the discharge level sensor, and the discharge controller actuating the discharge valve based on at least the signal of the discharge level sensor, whereby the discharge level and the feed flow level are maintained using the signal of the discharge level sensor as an input. An apparatus includes a feed fluid inlet, an evaporator-condenser apparatus including a substantially cylindrical housing, and a plurality of tubes in the housing, the feed fluid inlet being fluidly connected to the evaporator-condenser, which converts the feed fluid into vapor and the compressed vapor into a product fluid, the apparatus further including a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger including an outer tube and at least one inner tube, and the apparatus includes a regenerative blower fluidly connected to the evaporator-condenser, the regenerative blower compressing the vapor, the compressed vapor flowing to the evaporative condenser, and the compressed vapor being converted into a product fluid. The heat exchanger is disposed around the evaporator-condenser housing. The heat exchanger includes an outer tube that is a feed fluid flow path and at least one inner tube that is a product fluid flow path. The heat exchanger further includes at least three inner tubes, which are twisted together to form a substantially helical shape. Where the heat exchanger further includes two ends, each end having a connector attached thereto, the connectors forming a joint with the evaporator-condenser. Where the evaporator-condenser tubes further include a packing inside the tubes. Where the packing is rods. Where the evaporator-condenser further includes a steam chamber fluidly connected to the plurality of tubes. Where the regenerative blower further includes an impeller assembly driven by a magnetic drive coupling. Where the control system includes at least two processors: a motor control engine processor and an ARM(R) processor.When the fluid vapor distillation apparatus further includes a conductivity meter and a conductivity cell for measuring the conductivity of the product fluid.

[0018] According to one aspect of the present invention, a fluid vapor distillation apparatus is disclosed. The apparatus includes a feed fluid inlet and an evaporator-condenser apparatus. The evaporator-condenser apparatus includes a substantially cylindrical housing and a plurality of tubes within the housing. The feed fluid inlet is fluidly connected to the evaporator-condenser, which converts the feed fluid into vapor and the compressed vapor into a product fluid. The fluid vapor distillation apparatus also includes a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet. The heat exchanger includes an outer tube and at least one inner tube. The fluid vapor distillation apparatus also includes a regenerative blower fluidly connected to the evaporator-condenser. The regenerative blower compresses the vapor, and the compressed vapor flows to the evaporative condenser, where the compressed vapor is converted into a product fluid. The fluid vapor distillation apparatus also includes a control system.

[0019] Some embodiments of this aspect of the invention include one or more of: where the heat exchanger is disposed around the evaporator-condenser housing; where the heat exchanger further includes a heat exchanger, wherein the outer tube is a fluid flow path and at least one inner tube is a product fluid flow path; where the heat exchanger further includes at least three inner tubes; where the at least three inner tubes are wound to form a substantially helical shape; where the heat exchanger further includes two ends with connectors attached at each end, the connectors forming connections to the evaporator-condenser; where the evaporator-condenser tubes further include packing inside the tubes, wherein the packing is rods; where the evaporator-condenser further includes a vapor chamber fluidly connected to the plurality of tubes; and where the regenerative blower further includes an impeller assembly driven by a magnetic drive linkage.

[0020] According to another aspect of the present invention, a water vapor distillation system is disclosed. The water vapor distillation system includes a feed fluid input and an evaporator-condenser apparatus. The evaporator-condenser apparatus includes a substantially cylindrical housing and a plurality of tubes within the housing. The feed fluid input is fluidly connected to the evaporator-condenser, which converts the feed fluid into vapor and converts the compressed vapor into a product fluid. The water vapor distillation system also includes a heat exchanger fluidly connected to the feed fluid input and the product fluid output. The heat exchanger includes an outer tube and at least one inner tube. The water vapor distillation system also includes a regenerative blower fluidly connected to the evaporator-condenser. The regenerative blower compresses the vapor, and the compressed vapor flows to the evaporator-condenser, where the compressed vapor is converted into a product fluid.

[0021] The steam distillation system also includes a Stirling engine electrically connected to the steam distillation apparatus, the Stirling engine at least partially powering the steam distillation apparatus.

[0022] Some embodiments of this aspect of the invention include a Stirling engine including at least one rocking drive mechanism, the rocking drive mechanism including a rocking beam having a rocker pivot, at least one cylinder, and at least one piston. A piston is housed within each cylinder. The piston is capable of substantially linear reciprocating motion within each cylinder. The drive mechanism also includes at least one linkage assembly having a proximal end and a distal end. The proximal end is connected to the piston, and the distal end is connected to the rocking beam by an end pivot. Linear motion of the piston is converted into rotational motion of the rocking beam. Also included is a crankcase that houses the rocking beam and houses a first portion of the linkage assembly. Also included is a crankshaft connected to the rocking beam by a connecting rod. Rotational motion of the rocking beam is transmitted to the crankshaft. The machine also includes a working space that houses at least one cylinder, at least one piston, and a second portion of the linkage assembly. A seal is included to seal the working space from the crankcase.

[0023] Additionally, some embodiments of this aspect of the invention include any one or more of: where the seal is a rolling diaphragm; where the linkage assembly further includes a piston rod and a link rod; where the piston rod and link rod are connected together by a linkage; where the heat exchanger is disposed around the evaporator-condenser housing; where the heat exchanger further includes a heat exchanger where the outer tube is the fluid flow path and at least one inner tube is the product fluid flow path; where the heat exchanger further includes at least three inner tubes; where the evaporator-condenser further includes a steam chest fluidly connected to the plurality of tubes; and where the regenerative blower further includes an impeller assembly driven by a magnetic drive linkage.

[0024] These aspects of the present invention are not intended to be exhaustive, and other features, aspects, and advantages of the present invention will become readily apparent to those skilled in the art when read in conjunction with the appended claims and accompanying drawings. [Brief explanation of the drawings]

[0025] These and other features and advantages of the present invention will be better understood from a reading of the following detailed description in conjunction with the drawings. [Figure 1] FIG. 1 is an isometric view of a steam distillation apparatus. [Figure 1A] FIG. 1A is an exploded view of an exemplary embodiment of the present disclosure. [Figure 1B] FIG. 1B is a cross-sectional view of an exemplary embodiment. [Figure 1C] FIG. 1C is a cross-sectional view of an exemplary embodiment. [Figure 1D] FIG. 1D is an assembled view of an exemplary embodiment. [Figure 1E] FIG. 1E is a detailed view of an exemplary embodiment of a frame. [Figure 1F] FIG. 1F is an assembly view of an alternative embodiment. [Figure 1G] FIG. 1G is an assembly view of an alternative embodiment. [Figure 1H] FIG. 1H is an assembly view of an alternative embodiment. [Figure 2] FIG. 2 is an assembled view of an exemplary embodiment of a tube-in-tube heat exchanger assembly. [Figure 2A] FIG. 2A is an exploded view of one embodiment of a tube-in-tube heat exchanger. [Figure 2B] FIG. 2B is a rear isometric view of an exemplary embodiment of a tube-in-tube heat exchanger. [Figure 2C] FIG. 2C is a front isometric view of an exemplary embodiment of a tube-in-tube heat exchanger. [Figure 2D] FIG. 2D is a cross-sectional view of one embodiment of a tube-in-tube heat exchanger. [Figure 2E] FIG. 2E is an exploded view of an alternative embodiment of a tube-in-tube heat exchanger. [Figure 2F] FIG. 2F is a cutaway view of an embodiment of a tube-in-tube heat exchanger illustrating the helical arrangement of the inner tubes. [Figure 2G] FIG. 2G is an exploded view of an alternative embodiment of a tube-in-tube heat exchanger. [Figure 2H] FIG. 2H is an isometric view of an exemplary embodiment of a tube-in-tube heat exchanger. [Figure 2I] FIG. 2I is an isometric view of an exemplary embodiment of a tube-in-tube heat exchanger. [Figure 2J] FIG. 2J is an exploded view of an alternative embodiment of a tube-in-tube heat exchanger configuration. [Figure 2K] FIG. 2K is an assembly drawing of an alternative embodiment of a tube-in-tube heat exchanger configuration. [Figure 2L] FIG. 2L is an assembly drawing of an alternative embodiment of a tube-in-tube heat exchanger configuration. [Figure 2M] FIG. 2M is a detailed view of an alternative embodiment of a tube-in-tube heat exchanger configuration. [Figure 2N] FIG. 2N is a detailed view of an alternative embodiment of a tube-in-tube heat exchanger configuration. [Figure 2O]FIG. 2O is a schematic diagram of an alternative embodiment of a tube-in-tube heat exchanger configuration. [Figure 2P] FIG. 2P is an assembly view of an alternative embodiment of the heat exchanger. [Figure 2Q] FIG. 2Q is an exploded view of an alternative embodiment of a heat exchanger. [Figure 2R] FIG. 2R is a cross-sectional view of an alternative embodiment of a heat exchanger. [Figure 3] FIG. 3 is an exploded view of a connector for a fitting assembly for a tube-in-tube heat exchanger. [Figure 3A] FIG. 3A is a cross-sectional view of a fitting assembly for a tube-in-tube heat exchanger. [Figure 3B] FIG. 3B is a cross-sectional view of a fitting assembly for a tube-in-tube heat exchanger. [Figure 3C] FIG. 3C is an isometric view of an exemplary embodiment of the first connector. [Figure 3D] FIG. 3D is a cross-sectional view of an exemplary embodiment of the first connector. [Figure 3E] FIG. 3E is a cross-sectional view of an exemplary embodiment of the first connector. [Figure 3F] FIG. 3F is a cross-sectional view of an exemplary embodiment of the first connector. [Figure 3G] FIG. 3G is an isometric view of an exemplary embodiment of the second connector. [Figure 3H] FIG. 3H is a cross-sectional view of a fitting assembly for a tube-in-tube heat exchanger. [Figure 3I] FIG. 3I is a cross-sectional view of an exemplary embodiment of the second connector. [Figure 3J] FIG. 3J is a cross-sectional view of an exemplary embodiment of the second connector. [Figure 4] FIG. 4 is an isometric view of an exemplary embodiment of an evaporator / condenser assembly. [Figure 4A] FIG. 4A is a cross-sectional view of an exemplary embodiment of an evaporator / condenser assembly. [Figure 4B] FIG. 4B is an isometric cross-sectional view of an exemplary embodiment of an evaporator / condenser. [Figure 4C] FIG. 4C is an isometric view of an alternative embodiment of the evaporator / condenser assembly. [Figure 5] FIG. 5 is an assembly view of an exemplary embodiment of a basin. [Figure 5A] FIG. 5A is an exploded view of an exemplary embodiment of a basin. [Figure 6] FIG. 6 is an isometric detail view of a flange for a sump assembly. [Figure 7] FIG. 7 is an exploded view of an exemplary embodiment of an evaporator / condenser. [Figure 7A] FIG. 7A is a top view of an exemplary embodiment of an evaporator / condenser assembly. [Figure 7B] FIG. 7B shows the percentage of distillate output of the evaporator as a function of pressure for several liquid boiling modes. [Figure 8] FIG. 8 is an isometric view of an exemplary embodiment of a tube for an evaporator / condenser. [Figure 9] FIG. 9 is an exploded view of the tube and rod configuration for the evaporator / condenser. [Figure 9A] FIG. 9A is an isometric view of an exemplary embodiment of an evaporator / condenser rod. [Figure 10] FIG. 10 is an isometric view of an exemplary embodiment of a sump tube plate. [Figure 10A] FIG. 10A is an isometric view of an exemplary embodiment of an upper tube sheet. [Figure 11] FIG. 11 is a detailed view of the top cap for the evaporator / condenser. [Figure 12] FIG. 12 is an isometric view of an exemplary embodiment of a steam chest. [Figure 12A] FIG. 12A is an isometric view of an exemplary embodiment of a steam chest. [Figure 12B] FIG. 12B is a cross-sectional view of an exemplary embodiment of a steam chest. [Figure 12C] FIG. 12C is an exploded view of an exemplary embodiment of a steam chest. [Figure 12D] FIG. 12D is an isometric view of an alternative embodiment. [Figure 12E]FIG. 12E is a cross-sectional view of an exemplary embodiment of a steam chest. [Figure 12F] FIG. 12F is a cross-sectional view of an exemplary embodiment of a steam chest. [Figure 13] FIG. 13 is an assembly drawing of an alternative embodiment of the evaporator / condenser. [Figure 13A] FIG. 13A is a cross-sectional view of an alternative embodiment of an evaporator / condenser. [Figure 13B] FIG. 13B is an assembly drawing of an alternative embodiment of the evaporator / condenser illustrating the arrangement of the tubes. [Figure 13C] FIG. 13C is a cross-sectional view of an alternative embodiment of an evaporator / condenser illustrating the arrangement of the tubes. [Figure 13D] FIG. 13D is an isometric view of an alternative embodiment of an evaporator / condenser without a sump. [Figure 13E] FIG. 13E is an exploded view of an alternative embodiment of the evaporator / condenser. [Figure 14] FIG. 14 is an isometric view of the mist eliminator assembly. [Figure 14A] FIG. 14A is an isometric view of the outside of the cap for the mist eliminator. [Figure 14B] FIG. 14B is an isometric view of the inside of the cap for the mist eliminator. [Figure 14C] FIG. 14C is a cross-sectional view of the mist eliminator assembly. [Figure 14D] FIG. 14D is a cross-sectional view of the mist eliminator assembly. [Figure 15] FIG. 15 is an assembly view of an exemplary embodiment of a regenerative blower. [Figure 15A] FIG. 15A is a bottom view of an exemplary embodiment of a regenerative blower assembly. [Figure 15B] FIG. 15B is a top view of an exemplary embodiment of a regenerative blower assembly. [Figure 15C] FIG. 15C is an exploded view of an exemplary embodiment of a regenerative blower. [Figure 15D] FIG. 15D is a detailed view of the exterior of the top of the housing for the exemplary embodiment of the regenerative blower. [Figure 15E]FIG. 15E is a detailed view of the interior surface of the top of the housing for the exemplary embodiment of the regenerative blower. [Figure 15F] FIG. 15F is a detailed view of the interior surface of the lower portion of the housing for the exemplary embodiment of the regenerative blower. [Figure 15G] FIG. 15G is a detailed view of the exterior of the lower portion of the housing for the exemplary embodiment of the regenerative blower. [Figure 15H] FIG. 15H is a cross-sectional view of an exemplary embodiment of a regenerative blower. [Figure 15I] FIG. 15I is a cross-sectional view of an exemplary embodiment of a regenerative blower. [Figure 15J] FIG. 15J is a cross-sectional view of an exemplary embodiment of a regenerative blower. [Figure 15K] FIG. 15K is a schematic diagram of an exemplary embodiment of a regenerative blower assembly. [Figure 15L] FIG. 15L is a cross-sectional view of an exemplary embodiment of a regenerative blower. [Figure 16] FIG. 16 is a detailed view of the impeller assembly of an exemplary embodiment of a regenerative blower. [Figure 16A] FIG. 16A is a cross-sectional view of the impeller assembly. [Figure 17] FIG. 17 is an assembly drawing of an alternative embodiment of a regenerative blower. [Figure 17A] FIG. 17A is an assembly drawing of an alternative embodiment of a regenerative blower. [Figure 17B] FIG. 17B is a cross-sectional view of an alternative embodiment of a regenerative blower assembly. [Figure 17C] FIG. 17C is a cross-sectional view of an alternative embodiment of a regenerative blower assembly. [Figure 17D] FIG. 17D is a cross-sectional view of an alternative embodiment of a regenerative blower assembly. [Figure 17E] FIG. 17E is an exploded view of an alternative embodiment of a regenerative blower. [Figure 17F] FIG. 17F is an assembly drawing of the impeller housing. [Figure 17G] FIG. 17G is an exploded view of the impeller housing. [Figure 17H]FIG. 17H is a cross-sectional view of an alternative embodiment of an impeller housing assembly. [Figure 17I] FIG. 17I is a cross-sectional view of an alternative embodiment of an impeller housing assembly. [Figure 17J] FIG. 17J is a bottom view of the lower portion of the impeller housing. [Figure 17K] FIG. 17K is a detailed view of the interior surface of the lower portion of the impeller housing. [Figure 17L] FIG. 17L is a top view of the upper portion of the impeller housing assembly. [Figure 17M] FIG. 17M is a top view of the upper portion of the housing for the impeller assembly without the cover installed. [Figure 17N] FIG. 17N is a detailed view of the interior of the top of the housing for the impeller assembly. [Figure 18] FIG. 18 is a detailed view of the impeller assembly for an alternative embodiment of the regenerative blower. [Figure 18A] FIG. 18A is a cross-sectional view of the impeller assembly. [Figure 19] FIG. 19 is an assembly drawing of the level sensor assembly. [Figure 19A] FIG. 19A is an exploded view of an exemplary embodiment of a level sensor assembly. [Figure 19B] FIG. 19B is a cross-sectional view of the settling tank within the level sensor housing. [Figure 19C] FIG. 19C is a cross-sectional view of the release sensor and product level sensor reservoir within the level sensor housing. [Figure 19D] FIG. 19D is an assembly view of an alternative embodiment of the level sensor assembly. [Figure 19E] FIG. 19E is an exploded view of an alternative embodiment of the level sensor assembly. [Figure 19F] FIG. 19F is a cross-sectional view of an alternative embodiment of a level sensor assembly. [Figure 19G] FIG. 19G is a schematic diagram of the operation of the level sensor assembly. [Figure 19H] FIG. 19H is an alternative embodiment of the level sensor assembly. [Figure 20] FIG. 20 is an isometric view of the level sensor assembly. [Figure 20A] FIG. 20A is a cross-sectional view of the level sensor assembly. [Figure 21] FIG. 21 is a front isometric view of the bearing feed pump. [Figure 21A] FIG. 21A is an isometric view of the rear side of the bearing feed pump. [Figure 22] FIG. 22 is a schematic diagram of the source water flow path for an exemplary embodiment of a water vapor distillation apparatus. [Figure 22A] FIG. 22A is a schematic diagram of source water entering a heat exchanger. [Figure 22B] FIG. 22B is a schematic diagram of source water passing through a heat exchanger. [Figure 22C] FIG. 22C is a schematic diagram of the source water exiting the heat exchanger. [Figure 22D] FIG. 22D is a schematic diagram of source water passing through a regenerative blower. [Figure 22E] FIG. 22E is a schematic diagram of source water exiting and entering the regenerative blower. [Figure 23] FIG. 23 is a schematic diagram of the blowdown water flow path for an exemplary embodiment of a water vapor distillation apparatus. [Figure 23A] FIG. 23A is a schematic diagram of blow-off water exiting the evaporator / condenser assembly and entering the level sensor housing. [Figure 23B] FIG. 23B is a schematic diagram of blowdown water filling the settling tank within the level sensor housing. [Figure 23C] FIG. 23C is a schematic diagram of blow-off water filling the blow-off level sensor reservoir within the level sensor housing. [Figure 23D] FIG. 23D is a schematic diagram of blowdown water exiting the level sensor housing and entering the strainer. [Figure 23E] FIG. 23E is a schematic diagram of blowdown water exiting the strainer and entering the heat exchanger. [Figure 23F] FIG. 23F is a schematic diagram of blowdown water passing through a heat exchanger. [Figure 23G]FIG. 23G is a schematic diagram of blowdown water exiting the heat exchanger. [Figure 24] FIG. 24 is a schematic diagram of the product water flow path for an exemplary embodiment of a water vapor distillation apparatus. [Figure 24A] FIG. 24A is a schematic diagram of product water exiting the evaporator / condenser assembly and entering the level sensor housing. [Figure 24B] FIG. 24B is a schematic diagram of product water entering the product level sensor reservoir within the level sensor housing. [Figure 24C] FIG. 24C is a schematic diagram of the product water exiting the product level sensor reservoir and entering the heat exchanger. [Figure 24D] FIG. 24D is a schematic diagram of product water passing through a heat exchanger. [Figure 24E] FIG. 24E is a schematic diagram of the product water exiting the heat exchanger. [Figure 24F] FIG. 24F is a schematic diagram of product water entering the bearing feedwater reservoir within the level sensor housing. [Figure 24G] FIG. 24G is a schematic diagram of the product water exiting the level sensor housing and entering the bearing feed pump. [Figure 24H] FIG. 24H is a schematic diagram of the product water exiting the bearing feed pump and entering the regenerative blower. [Figure 24I] FIG. 24I is a schematic diagram of the product water exiting the regenerative blower and entering the level sensor housing. [Figure 25] FIG. 25 is a schematic diagram of an air passage for an exemplary embodiment of a water vapor distillation apparatus. [Figure 25A] FIG. 25A is a schematic diagram of the vent path that allows air to exit the emission sensor reservoir and enter the evaporative condenser. [Figure 25B] FIG. 25B is a schematic diagram of the vent path that allows air to exit the product sensor reservoir and enter the evaporative condenser. [Figure 25C] FIG. 25C is a schematic diagram of the vent path that allows air to exit the evaporator / condenser assembly. [Figure 26]FIG. 26 is a schematic diagram of low pressure steam entering the tubes of the evaporator / condenser assembly from the sump. [Figure 26A] FIG. 26A is a schematic diagram of low pressure steam passing through the tubes of an evaporator / condenser assembly. [Figure 26B] FIG. 26B is a schematic diagram of wet low pressure steam exiting the tubes of the evaporator / condenser assembly and entering the steam chest. [Figure 26C] FIG. 26C is a schematic diagram of wet low-pressure steam flowing through the vapor chest of the evaporator / condenser assembly. [Figure 26D] FIG. 26D is a schematic diagram of the production of blowdown water as low pressure steam passing through the steam chest. [Figure 26E] FIG. 26E is a schematic diagram of dry low pressure steam exiting the steam chest and entering the regenerative blower. [Figure 26F] FIG. 26F is a schematic diagram of dry low-pressure steam passing through a regenerative blower. [Figure 26G] FIG. 26G is a schematic diagram of high pressure steam exiting the regenerative blower. [Figure 26H] FIG. 26H is a schematic diagram of high pressure steam entering a steam pipe. [Figure 26I] FIG. 26I is a schematic diagram of high pressure steam exiting the steam line and entering the evaporator / condenser chamber. [Figure 26J] FIG. 26J is a schematic diagram of the generation of product water from high pressure steam condensing in an evaporator / condenser chamber. [Figure 27] FIG. 27 is a graph illustrating the relationship between the differential pressure across the regenerative blower and the amount of energy required to produce one liter of product. [Figure 28] FIG. 28 is a graph illustrating the relationship between product production rate and the number of heat transfer tubes in the evaporator / condenser assembly. [Figure 29] FIG. 29 is a graph illustrating the product water production rate of an evaporator / condenser assembly as a function of the amount of heat transfer surface area associated with the evaporator / condenser chamber. [Figure 30]FIG. 30 is a graph illustrating the heat transfer surface efficiency for varying amounts of heat transfer tubes in an evaporator / condenser assembly as it relates to changes in pressure across the regenerative blower. [Figure 31] FIG. 31 is a graph illustrating the amount of energy consumed by the evaporator / condenser assembly at different pressure differentials across production rates and regenerative blowers. [Figure 32] FIG. 32 is a cross-sectional top view of a rotor and stator according to a particular embodiment, showing the support structure for the input, the blades and chambers between the blades, and the rotating drive shaft. [Figure 32A] FIG. 32A is a side top view of the rotor and stator corresponding to the embodiment shown in FIG. 32, showing the support structures for the input and output, the blades, the eccentric arrangement within the housing unit, and the drive shaft. [Figure 32B] FIG. 32B is a top view of the rotor and stator corresponding to the embodiment shown in FIGS. 32 and 32A, showing the support structures for the input and output, the blades, the eccentric arrangement within the housing unit, and the drive shaft. [Figure 32C] FIG. 32C is a cross-sectional view of the rotor and stator corresponding to the embodiment shown in FIGS. 32, 32A, and 32B, showing the blades, drive shaft, and bearings. [Figure 32D] FIG. 32D is a cross-sectional view of a liquid ring pump according to one embodiment showing a capacitance sensor. [Figure 32E] FIG. 32E is a cross-sectional view of a liquid ring pump according to one embodiment showing the eccentric rotor, rotor blades, drive shaft with bearings, rotating housing unit for the liquid ring pump, stationary housing, and the cyclone effect from the steam and the resulting exclusion of mist and water droplets. [Figure 32F] FIG. 32F is a schematic diagram of an alternative embodiment of a liquid ring pump. [Figure 32G] FIG. 32G is a top view of an alternative embodiment of a rotor showing multiple vanes and chambers between the vanes, as well as the intake and exit holes for each individual chamber. [Figure 32H]FIG. 32H is further detail of the liquid ring pump showing the stationary intake port and rotating drive shaft, rotor, and housing unit. [Figure 32I] FIG. 32I is a diagram of a seal that may be present between the stationary and rotor portions of a liquid ring pump, separating the intake from the outlet. [Figure 33] FIG. 33 is a side view of a backpressure regulator according to one embodiment. [Figure 33A] FIG. 33A is a diagonal view of the backpressure regulator shown. [Figure 33B] FIG. 33B is a side view of an alternative embodiment of a backpressure regulator having vertically oriented ports. [Figure 33C] FIG. 33C is a diagonal view of the backpressure regulator shown. [Figure 33D] FIG. 33D is an enlarged view of portion C of FIG. 33D depicting the port cutouts of the backpressure regulator. [Figure 33E] FIG. 33E is a close-up view of section C of FIG. 33D, depicting the ports of the backpressure regulator. [Figure 33F] FIG. 33F is a cutaway side view of one embodiment of a backpressure regulator. [Figure 33G] FIG. 33G is an enlarged view of portion E of FIG. 33F depicting the small opening of the backpressure regulator port. [Figure 34] FIG. 34 is a schematic diagram of a backpressure regulator implemented within the device. [Figure 35] FIG. 35 is a schematic diagram of an alternative embodiment of a water vapor distillation apparatus. [Figure 35A] FIG. 35A is a detailed schematic diagram of an alternative embodiment of the level sensor housing depicting external connection valves between the source and discharge fluid lines. [Figure 36] FIG. 36 is a view of the pump side of the fluid distribution manifold. [Figure 36A] FIG. 36A is a view of the second face of the pump side of the fluid distribution manifold. [Figure 36B] FIG. 36B is a side view of the evaporator / condenser side of the fluid distribution manifold. [Figure 36C]FIG. 36C is a view of the second face of the evaporator / condenser side of the fluid distribution manifold. [Figure 37] FIG. 37 is a top view of a coupler of an alternative embodiment of a fitting assembly. [Figure 37A] 37A is a side view of an alternative embodiment of the fitting assembly of FIG. 37. FIG. [Figure 38] FIG. 38 is a cross-sectional view of an alternative embodiment of an evaporator / condenser having separate heating layers and ribs. [Figure 38A] FIG. 38A is a cross-sectional detail of an alternative embodiment of an evaporator / condenser showing how the ribs effectively separate the vapor / evaporation from the liquid / condensate layer. [Figure 39] FIG. 39 is a schematic diagram of an alternative embodiment of a heat exchanger. [Figure 39A] FIG. 39A is a schematic diagram of an alternative embodiment of a heat exchanger. [Figure 40] FIG. 40 is a schematic overview of an alternative embodiment of a water vapor distillation apparatus that includes system pressure measurement using a cold air sensor. [Figure 41] FIG. 41 shows a diagram of a flip filter with the intake and discharge streams flowing through the filter units, each of which rotates about a pivot joint about a central axis. [Figure 41A] FIG. 41A shows a flip filter housing. [Figure 41B] FIG. 41B is a detailed diagram of the flip filter of FIG. [Figure 41C] FIG. 41C is an alternative embodiment of a composite flip filter. [Figure 41D] FIG. 41D is a schematic diagram of an alternative embodiment of a flip filter. [Figure 41E] FIG. 41E is a schematic diagram of the flow path of one embodiment of a flip filter. [Figure 41F] FIG. 41F is a schematic diagram illustrating a manual switch for varying the water flow through the individual units of the flip filter of FIG. 41E. [Figure 42] FIG. 42 is a depiction of a surveillance system for a distributed public facility. [Figure 43] Figure 43 is a depiction of a distribution system for a public facility. [Figure 44] FIG. 44 is a conceptual flow diagram of a possible embodiment of a system incorporating an alternative embodiment of a water vapor distillation apparatus. [Figure 44A] FIG. 44A is a schematic block diagram of a power supply for use with the system shown in FIG. [Figure 45A] FIG. 45A illustrates the principle of operation of a Stirling cycle machine. [Figure 45B] FIG. 45B illustrates the principle of operation of a Stirling cycle machine. [Figure 45C] FIG. 45C illustrates the principle of operation of a Stirling cycle machine. [Figure 45D] FIG. 45D illustrates the principle of operation of a Stirling cycle machine. [Figure 45E] FIG. 45E illustrates the principle of operation of a Stirling cycle machine. [Figure 46] FIG. 46 shows a diagram of a rocking beam drive, according to one embodiment. [Figure 47] FIG. 47 shows a diagram of a rocking beam drive, according to one embodiment. [Figure 48] FIG. 48 shows a diagram of an engine, according to one embodiment. [Figure 49A] FIG. 49A depicts various views of a rocking beam drive, according to one embodiment. [Figure 49B] FIG. 49B depicts various views of a rocking beam drive, according to one embodiment. [Figure 49C] FIG. 49C depicts various views of a rocking beam drive, according to one embodiment. [Figure 49D] FIG. 49D depicts various views of a rocking beam drive, according to one embodiment. [Figure 50] FIG. 50 shows a bearing style rod connector, according to one embodiment. [Figure 51A] FIG. 51A shows a bend, according to one embodiment. [Figure 51B]FIG. 51B shows a bend, according to one embodiment. [Figure 52] FIG. 52 shows a four-cylinder dual rocking beam drive arrangement, according to one embodiment. [Figure 53] FIG. 53 shows a cross section of a crankshaft according to one embodiment. [Figure 54A] FIG. 54A shows a diagram of an engine, according to one embodiment. [Figure 54B] FIG. 54B shows a crankshaft connection according to one embodiment. [Figure 54C] FIG. 54C shows a diagram of a sleeve rotor, according to one embodiment. [Figure 54D] FIG. 54D shows a view of a crankshaft, according to one embodiment. [Figure 54E] FIG. 54E is a cross section of a sleeve rotor and splined shaft according to one embodiment. [Figure 54F] FIG. 54F is a cross section of a crankshaft and splined shaft according to one embodiment. [Figure 54G] FIG. 54G shows various views of a sleeve rotor, crankshaft, and splined shaft according to one embodiment. [Figure 55] FIG. 55 illustrates the operation of a piston in an engine, according to one embodiment. [Figure 56A] FIG. 56A shows an unpackaged schematic view of the workspace and cylinder, according to one embodiment. [Figure 56B] FIG. 56B shows a schematic diagram of the cylinder, heater head, and regenerator according to one embodiment. [Figure 56C] FIG. 56C shows a view of a cylinder head, according to one embodiment. [Figure 57A] FIG. 57A shows a view of a rolling diaphragm with supporting top and bottom seal pistons, according to one embodiment. [Figure 57B] FIG. 57B is an exploded view of a rocking beam drive engine, according to one embodiment. [Figure 57C]FIG. 57C shows a diagram of the cylinder, heater head, regenerator, and rolling diaphragm according to one embodiment. [Figure 57D] FIG. 57D shows various views of a rolling diaphragm in operation, according to one embodiment. [Figure 57E] FIG. 57E shows various views of a rolling diaphragm in operation, according to one embodiment. [Figure 57F] FIG. 57F shows an unpackaged schematic view of the workspace and cylinder, according to one embodiment. [Figure 57G] FIG. 57G shows a diagram of an external combustion engine, according to one embodiment. [Figure 58A] FIG. 58A shows diagrams of various embodiments of rolling diaphragms. [Figure 58B] FIG. 58B shows diagrams of various embodiments of rolling diaphragms. [Figure 58C] FIG. 58C shows diagrams of various embodiments of rolling diaphragms. [Figure 58D] FIG. 58D shows diagrams of various embodiments of rolling diaphragms. [Figure 58E] FIG. 58E shows diagrams of various embodiments of rolling diaphragms. [Figure 59A] FIG. 59A shows a diagram of a metal bellows and associated piston rod and piston, according to one embodiment. [Figure 59B] FIG. 59B shows a diagram of a metal bellows diaphragm, according to one embodiment. [Figure 59C] FIG. 59C shows a diagram of a metal bellows diaphragm, according to one embodiment. [Figure 59D] FIG. 59D shows a diagram of a metal bellows diaphragm, according to one embodiment. [Figure 59E] FIG. 59E shows a diagram of a metal bellows, according to various embodiments. [Figure 59F] FIG. 59F shows a diagram of a metal bellows, according to various embodiments. [Figure 59G] FIG. 59G shows a diagram of a metal bellows, according to various embodiments. [Figure 59H] FIG. 59H shows a schematic of a rolling diaphragm identifying the various load regions. [Figure 59I] FIG. 59I shows a schematic diagram of a rolling diaphragm identifying the convolution regions. [Figure 60] FIG. 60 shows a diagram of a piston and piston seal, according to one embodiment. [Figure 61] FIG. 61 shows a diagram of a piston rod and piston rod seal, according to one embodiment. [Figure 62A] FIG. 62A shows a diagram of a piston seal backing ring, according to one embodiment. [Figure 62B] FIG. 62B shows a pressure diagram for the backing ring, according to one embodiment. [Figure 62C] FIG. 62C shows a piston seal, according to one embodiment. [Figure 62D] FIG. 662D shows a piston seal, according to one embodiment. [Figure 62E] FIG. 62E shows a piston rod seal, according to one embodiment. [Figure 62F] FIG. 62F shows a piston rod seal, according to one embodiment. [Figure 63A] FIG. 63A shows a diagram of a piston seal backing ring, according to one embodiment. [Figure 63B] FIG. 63B shows a pressure diagram for a piston seal backing ring, according to one embodiment. [Figure 64A] FIG. 64A shows a diagram of a piston rod seal backing ring, according to one embodiment. [Figure 64B] FIG. 64B shows a pressure diagram for a piston rod seal backing ring, according to one embodiment. [Figure 65] FIG. 65 shows a view of a piston guide ring, according to one embodiment. [Figure 66] FIG. 66 shows an unpackaged schematic view of the workspace and cylinder, according to one embodiment. [Figure 67A] FIG. 67A shows a diagram of an engine, according to one embodiment. [Figure 67B] FIG. 67B shows a diagram of an engine, according to one embodiment. [Figure 68] FIG. 68 shows a diagram of a crankshaft, according to one embodiment. [Figure 69A] FIG. 69A shows various configurations of pump drives, according to various embodiments. [Figure 69B] FIG. 69B shows various configurations of pump drives, according to various embodiments. [Figure 69C] FIG. 69C shows various configurations of pump drives, according to various embodiments. [Figure 70A] FIG. 70A shows various views of an oil pump, according to one embodiment. [Figure 70B] FIG. 70B shows a diagram of an engine, according to one embodiment. [Figure 70C] FIG. 70C shows another view of the engine depicted in FIG. 70B. [Figure 71A] FIG. 71A shows a diagram of an engine, according to one embodiment. [Figure 71B] FIG. 71B shows a diagram of an engine, according to one embodiment. [Figure 71C] FIG. 71C shows a diagram of a coupling joint, according to one embodiment. [Figure 71D] FIG. 71D shows a diagram of the crankshaft and splined shaft of the engine, according to one embodiment. [Figure 72A] FIG. 72A shows an illustration of a generator connected to one embodiment of the device. [Figure 72B] FIG. 72B shows a schematic diagram of an auxiliary power unit for providing power and heat to the water vapor distillation apparatus. [Figure 72C] FIG. 72C shows a schematic diagram of the system, according to one embodiment. [Figure 73] FIG. 73 is a schematic diagram of the flow path according to one embodiment of a water vapor distillation apparatus. [Figure 74] FIG. 74 is an isometric view of an embodiment of a tube-in-tube heat exchanger with an embodiment of a connector attached. [Figure 74A]FIG. 74A is an isometric view of one embodiment of the connector shown in FIG. [Figure 74B] 74B is a cross-sectional view of one embodiment of the connector shown in FIG. [Figure 74C] 74C is an end view of one embodiment of the connector shown in FIG. [Figure 75] FIG. 75 is a flow diagram of the water operating states. [Figure 76] FIG. 76 is a schematic diagram of a communication system with at least one water vapor distillation device, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] Definitions. As used in this description and the appended claims, the following terms shall have the meanings indicated, unless the context requires otherwise.

[0027] The term "fluid" is used herein to include any type of fluid, including water. Thus, although exemplary embodiments and various other embodiments are described herein with respect to water, the scope of the devices, systems, and methods includes any type of fluid. The term "liquid" may also be used herein to refer to exemplary embodiments in which the fluid is a liquid.

[0028] The term "evaporator-condenser" is used herein to refer to a device that is a combined evaporator and condenser. Thus, a structure is referred to as an evaporator-condenser when the structure itself performs both functions. Evaporator-condenser structures are referred to herein as evaporators / condensers, evaporator-condensers, or evaporators and condensers. Furthermore, in some cases, when either the evaporator or the condenser are individually referenced, the term is understood to refer to the evaporator-condenser structure without limitation.

[0029] The term "dirty water" is used herein to refer to any water for which it is desirable to make it more clean before consumption.

[0030] "Cleaner water" is used herein to refer to water that is cleaner as product water than as source water.

[0031] The term "source water" refers to any water that enters the device.

[0032] The term "product water" refers to the cleaner water that exits the device.

[0033] As used herein and in any accompanying claims, the term "purifying" refers to reducing the concentration of one or more contaminants or otherwise modifying the concentration of one or more contaminants.

[0034] As used herein, the term "specified level" refers to some desired level of concentration as established by a user for a particular application. One example of a specified level may be limiting contaminant levels in a fluid to carry out an industrial or commercial process. One example is eliminating contaminant levels in a solvent or reactant to an acceptable level to enable an industrially significant benefit in a chemical reaction (e.g., polymerization). Another example of a specified level may be a certain contaminant level in a fluid as defined by a government or intergovernmental agency for safety or health reasons. Examples may include the concentration of one or more contaminants in water used for drinking or for specific health or medical purposes, concentration levels defined by organizations such as the World Health Organization or the U.S. Environmental Protection Agency.

[0035] As used herein, the term "system" may refer to any combination of elements, including, but not limited to, a steam distillation apparatus (which may also be referred to as a water system or a steam distillation system), and a steam distillation apparatus with a power source, such as a Stirling engine.

[0036] Disclosed herein is an apparatus for distilling dirty water, known as source water, into cleaner water, known as product water. The apparatus purifies the source water by evaporating the water and separating particulates from the water. As used herein and in any accompanying claims, the term "purifying" refers to substantially reducing the concentration of one or more contaminants to below a specified level or substantially altering the concentration of one or more contaminants to within a specified range.

[0037] The source water may first pass through a counterflow tube-in-tube heat exchanger to increase the temperature of the water. Increasing the temperature of the source water reduces the amount of thermal energy required to evaporate the water in the evaporator / condenser. The source water may also receive thermal energy from other fluid streams present in the heat exchanger. Typically, these other streams have a higher temperature than the source water, causing thermal energy to flow from the higher temperature streams to the lower temperature source water.

[0038] The heated source water is received by the evaporator section of the evaporator / condenser assembly. This assembly evaporates the source water to separate contaminants from the water. Thermal energy may be supplied using a heating element and high-pressure steam. Typically, a heating element is used during initial startup; therefore, under normal operating conditions, thermal energy is provided by high-pressure steam. The source water fills the inner tubes of the evaporator section of the evaporator / condenser. As the high-pressure steam condenses on the outer surfaces of these tubes, thermal energy is transferred to the source water. This thermal energy evaporates some of the source water into low-pressure steam. After the source water is converted to low-pressure steam, the steam may exit the tube outlet and pass through a separator. The separator removes any remaining water droplets in the steam, ensuring that the low-pressure steam is dry before entering the compressor.

[0039] Upon exiting the evaporator of the evaporator / condenser, the low-pressure vapor enters the compressor. The compressor creates high-pressure vapor by compressing the low-pressure vapor. As the vapor is compressed, its temperature increases. Once at the elevated temperature and pressure, the vapor exits the compressor.

[0040] High-pressure steam enters the condenser area of ​​the evaporator / condenser. As the steam fills the interior cavity, it condenses on the tubes contained within the cavity. The high-pressure steam transfers heat energy to the source water within the tubes. This heat transfer causes the steam to condense on the exterior surfaces of the tubes, creating product water. The product water collects at the base of the condenser area of ​​the evaporator / condenser. The product water exits the evaporator area of ​​the evaporator / condenser and enters the level sensor housing.

[0041] The level sensor housing contains level sensors for determining the amount of product water and blowdown water in the system. These sensors allow an operator to adjust the amount of product water being produced or the amount of incoming source water depending on the water level in the system.

[0042] A water vapor distillation apparatus as described herein with respect to various embodiments may also be used in conjunction with a Stirling engine to form a water vapor distillation system. The power required by the water vapor distillation apparatus may be provided by a Stirling engine electrically connected to the water vapor distillation apparatus.

[0043] Referring to Figure 1, one embodiment of a water vapor distillation apparatus 100 is shown. For purposes of this description, the embodiment shown in Figure 1 will be referred to as the exemplary embodiment. Other embodiments are contemplated, some of which are discussed herein. The apparatus 100 may include a heat exchanger 102, an evaporator / condenser assembly 104, a regenerative blower 106, a level sensor assembly 108, a bearing feedwater pump 110, and a frame 112. See also Figures 1A-E for additional views and cross sections of the water vapor distillation apparatus 100.

[0044] Referring to Figures 1F-H, these figures illustrate alternative embodiments of a water vapor distillation apparatus 100. Figure 1F shows an apparatus 120 having an alternative configuration of an evaporator / condenser assembly 122. Similarly, Figure 1G discloses an apparatus having another configuration of an evaporator / condenser assembly 132. Similarly, Figure 1H illustrates another embodiment of the apparatus that does not include the level sensor assembly 108 and bearing feedwater pump 110 from Figures 1-1E. (heat exchanger) 2-2A, in an exemplary embodiment of a water vapor distillation apparatus, the heat exchanger may be a counter-flow tube-in-tube heat exchanger assembly 200. In this embodiment, heat exchanger assembly 200 may include an outer tube 202, a plurality of inner tubes 204, and a pair of connectors 206, as illustrated in FIG. 2A. An alternative embodiment of heat exchanger assembly 200 may not include connectors 206.

[0045] 2-2A, the heat exchanger assembly 200 may contain several independent fluid paths. In the exemplary embodiment, an outer tube 202 contains source water and four inner tubes 204. Three of these inner tubes 204 may contain product water generated by the device. The fourth inner tube may contain blowdown water.

[0046] 2-2A, the heat exchanger assembly 200 increases the temperature of the incoming source water and decreases the temperature of the outgoing product water. When the source water contacts the outer surface of the inner tube 204, thermal energy is transferred through the wall of the inner tube 204 from the higher temperature outgoing water to the lower temperature source water. Increasing the temperature of the source water improves the efficiency of the steam distillation apparatus 100 because source water with a higher temperature requires less energy to evaporate the water. Reducing the temperature of the product water also conditions the water for use by consumers.

[0047] 2-2A , in the exemplary embodiment, the heat exchanger 200 is a tube-in-tube heat exchanger having an outer tube 202 that has several functions. First, the outer tube 202 protects and contains the inner tube 204. The outer tube 202 protects the inner tube 204 from corrosion by acting as a barrier between the inner tube 204 and the surrounding environment. In addition, the outer tube 202 also improves the efficiency of the heat exchanger 200 by preventing the exchange of thermal energy with the surrounding environment. The outer tube 202 insulates the inner tube 204, reducing heat transfer to and from the surrounding environment. Similarly, the outer tube 202 may resist heat transfer from the inner tube 204, concentrating heat transfer to the source water and improving the efficiency of the heat exchanger 200.

[0048] Referring again to FIG. 2-2A , the outer tube 202 may be made of any material, although a low thermal conductivity is desirable. Low thermal conductivity is important because the outer tube 202 insulates the inner tube 204 from the surrounding environment. A low thermal conductivity of the outer tube improves the efficiency of the heat exchanger because the thermally conductive material reduces heat energy loss or gain to the surrounding environment. In addition, a low thermal conductivity material reduces the amount of heat energy that may be transferred from the inner tube 204 to the outer tube 202. This resistance to heat transfer allows more heat energy to be transferred to the source water rather than leaking out of the device through the outer tube 202. Thus, an outer tube 202 made of a material with low thermal conductivity allows more heat energy to be transferred to the source water rather than being lost or gained to the surrounding environment.

[0049] Still referring to FIGS. 2-2A , in an exemplary embodiment, the outer tube 202 is made of transparent silicone. In addition to having low thermal conductivity, silicone materials are also corrosion-resistant, which is an important property for preventing corrosion of the heat exchanger 200. The source water in the outer tube 202 may contain chemicals and / or other highly reactive materials. These materials may degrade outer tubing 202 made of other materials and reduce the useful life of the heat exchanger 200. In alternative embodiments, the outer tube 202 may be made of other materials, such as plastic or rubber, that are resistant to high temperatures. Also, in one embodiment, the outer tube 202 is made of convoluted tubing to improve mixing, which increases heat transfer efficiency.

[0050] 2B-C, another desirable characteristic is for the outer tubing 202 to be sufficiently resilient to support the placement of the heat exchanger 200 within the water vapor distillation apparatus 100. In some applications, space for the distillation apparatus may be limited by other environmental or situational constraints. For example, in the exemplary embodiment, the heat exchanger 200 encases the evaporator / condenser. In other embodiments, the heat exchanger may also be incorporated into the insulating cover of the water vapor distillation apparatus to minimize heat lost or gained from the environment. In an exemplary embodiment, the heat exchanger 200 may be configured in a coil as shown in Figures 2B-C. To achieve this configuration, the inner tube 204 is slid into the outer tube 202 and then wound around a mandrel. The resilient outer tube 202 aids in locating the end of the heat exchanger 200 at a specific location within the apparatus. Thus, having the resilient outer tube 202 may facilitate installation of the heat exchanger 200 within the water vapor distillation apparatus 100.

[0051] 2B-C , the elasticity of the material of the outer tubing 202 can also be affected by its wall thickness. Tubing with a thicker wall thickness is less flexible. However, a thicker wall thickness may improve the thermal properties of the tubing because thicker walls have better heat transfer resistance. In addition, the wall thickness of the tubing must be sufficient to withstand the internal pressure generated by the source water within the tubing. However, tubing with an increased wall thickness has reduced elasticity and increases the size of the heat exchanger assembly. Thicker-walled tubing requires a larger bend radius, which affects the installation of the heat exchanger 200. Conversely, tubing with too thin a wall thickness tends to kink during installation. This deformation of the tubing can restrict the flow of source water through the outer tubing 202 and reduce the efficiency of the heat exchanger 200.

[0052] The diameter of the outer tube 202 may be any diameter capable of containing multiple inner tubes 204. However, the larger the diameter, the less flexible the tubing. Reduced flexibility may adversely affect installation of the heat exchanger within the water vapor distillation apparatus 100. In the exemplary embodiment, the diameter of the outer tube 202 is 1 inch. This diameter allows the tube-in-tube heat exchanger 200 to be wrapped around the evaporator / condenser 104 upon final installation and contain four inner tubes 204 for transporting product water and blowdown water. In alternative embodiments, the heat exchanger may have as few as two inner tubes 204. Similarly, in other embodiments, the heat exchanger may have five or more inner tubes 204.

[0053] 2A and 2D, the inner pipes 204 may provide separate flow paths for source water, product water, and blowdown water. In the exemplary embodiment, these pipes contain product water and blowdown water. However, in other embodiments, the inner pipes may contain additional fluid flows. The inner pipes 204 separate the clean, safe product water from the contaminated, unhealthy source water and blowdown water. In the exemplary embodiment, there are three inner pipes 204 for product water and one inner pipe 204 for blowdown. The source water travels within the outer pipe 202 of the heat exchanger 200. In various other embodiments, the number of inner pipes may vary, i.e., a greater or lesser number of inner pipes may be included.

[0054] 2A and 2D , the inner tube 204 conducts thermal energy through the tube wall. Thermal energy flows through the tube wall from the hotter product and blowdown water within the inner tube 204 to the colder source water. Therefore, the inner tube 204 is preferably made of a material with high thermal conductivity and, in addition, is preferably made of a corrosion-resistant material. In the exemplary embodiment, the inner tube 204 is made of copper. The inner tube 204 may also be made of other materials, such as brass or titanium, depending on the preference for these other materials, which have high thermal conductivity and corrosion-resistant properties. For applications where the source and blowdown waters, such as seawater, are highly concentrated, the inner tube 204 may be made of, but is not limited to, copper-nickel, titanium, or a thermally conductive plastic.

[0055] In addition to the tubing material, the diameter and thickness of the tubing may also affect the rate of thermal energy transfer. Increasing the tubing wall thickness also increases resistance to heat transfer, so inner tubing 204 with a larger wall thickness may have less thermal efficiency. In the exemplary embodiment, the inner tube 204 has an outer diameter of 0.25 inches. While thinner wall thicknesses increase the rate of heat transfer, the wall thickness must be sufficient to be molded or formed without deformation. Thinner-walled tubing is more likely to kink, pinch, or collapse during forming. Additionally, the wall thickness of the inner tube 204 must be sufficient to withstand the internal pressure created by water passing through the tube.

[0056] 2A and 2D , additional methods for improving the heat transfer rate of the inner tube 204 may include a non-uniform inner tube diameter and extended surfaces on the inner tube to enhance heat transfer (fins, pins, ribs, etc.). In addition, the outer tube 202 may have a textured inner surface to create turbulence in the flow of source water and enhance heat transfer. The textured surface creates turbulence within the tube 202, increasing thermal conductivity. The turbulence increases the amount of water in contact with the outer surface of the inner tube 204, where heat transfer occurs. In contrast, without the textured surface, the water may flow in a more laminar manner. This laminar flow allows only a limited amount of water to contact the outer surface of the inner tube 204. The remaining water not in contact with the inner tube 204 does not receive much thermal energy because convective heat transfer between the water near the inner tube and the remaining water is not as efficient as heat transfer near the outer surface of the inner tube 204. Some examples of textured surfaces may include, but are not limited to, dimples, fins, ridges, or grooves. In another embodiment, they may be scaled to fit the outer tube to increase shell-side flow velocity and therefore enhance heat transfer.

[0057] Referring now to FIG. 2E, typically, the inner tubes 204 are arranged parallel to one another. However, in some embodiments, the inner tubes 204 are braided or wound together to form a spiral or substantially helical shape, as illustrated in FIGS. 2F-G. The spiral shape increases the amount of surface area for heat transfer because the length of the inner tubes 204 is longer than that of parallel-arranged inner tubes 204. The increased surface area provides additional area for heat transfer, thus increasing the efficiency of the heat exchanger 200. Additionally, the helical shape may induce turbulence in the source water within the outer tubing 202, improving heat transfer efficiency as discussed above. In the exemplary embodiment, the heat exchanger 200 has four inner tubes 204 arranged in a helical shape, as illustrated in FIGS. 2H-I.

[0058] The overall length of the tube-in-tube heat exchanger 200 is determined by the desired efficiency of the device. A heat exchanger 200 with a longer length results in better efficiency. In an exemplary embodiment, the heat exchanger 200 is approximately 50 feet long. This results in an efficiency of approximately 90%. Alternatively, a length of 25 feet results in an efficiency of approximately 84%.

[0059] 2, 2J, and 2K, the heat exchanger assembly 200 may also include connectors 206 at either end of the heat exchanger 200. In the exemplary embodiment, the heat exchanger 200 has two connectors located at either end of the assembly. These connectors 206 along the outer tube 202 define an internal cavity for containing source water. In addition, connectors attach to the ends of the inner tube 204 and provide separate fluid paths for product water and blowdown water to enter and / or exit the heat exchanger 200. The connectors 206 allow the heat exchanger assembly to be mechanically connected to an evaporator / condenser and other equipment components. In some embodiments, an extension 207 may be included in the heat exchanger 200 to provide an additional port for removing or supplying water to the heat exchanger 200.

[0060] 2L-O, these figures illustrate an alternative embodiment of a heat exchanger 200 having three inner tubes 204 passing through a connector 208. The connector 208 is sealed and attached to the inner tubes 204 and outer tube 202 at either end of the heat exchanger 200 to contain the source water inside the outer tube 202. An O-ring may be placed within the connector 208 to seal the interface between the connector 208 and the inner tube 204. This type of seal may allow the inner tube 204 to move freely and independently of the connector 208. Additionally, the inner tube 204 may be arranged in a helical configuration as shown in FIG. 2N. Referring to FIGS. 74-74C, another embodiment of a connector 7400 is shown, which may be used in any of the embodiments described herein.

[0061] 2P-R, these figures illustrate an alternative embodiment of heat exchanger 210. In this embodiment, the heat exchanger 210 is a flat-plate heat exchanger having a metal plate 212 and a plastic plate 214. The metal plate 212 may be made of any metallic material, such as stainless steel. Other embodiments may include, but are not limited to, plates made of titanium or a metal alloy. The plastic plate 214 is made of any type of plastic capable of functioning. In one embodiment, the flat-plate heat exchanger 210 is made of alternating metal and plastic plates. In other embodiments, the metal plate 212 may be followed by two or more plastic plates 214, as illustrated in FIG. 2R. The flat-plate heat exchanger 210 may begin and / or end with a plate 216 made of the same or a different material than the previous plate. In alternative embodiments, the plate 216 may be made of a metal or plastic material. The metal plate 212 is made of two metal plates stacked on top of each other, as shown in FIG. 2R, to form channels for fluid flow.

[0062] Referring now to FIG. 3, an exemplary embodiment of the counterflow tube-in-tube heat exchanger 200 may include a fitting assembly 300. The fitting assembly supports installation of the heat exchanger 200 within the water vapor distillation apparatus 100. Additionally, the fitting assembly 300 allows the heat exchanger 200 to be easily separated from the apparatus for maintenance. The assembly may consist of a first connector 302 (also identified as connector 206 in FIG. 2) and a second connector 310, shown in FIG. 3. See also FIGS. 3A-B for a cross-sectional view of the fitting assembly 300.

[0063] Still referring to FIG. 3 , in the exemplary embodiment, fitting assembly 300 is fabricated from brass. Other materials, including but not limited to, stainless steel, plastic, copper, copper-nickel, or titanium, may be used to fabricate fitting assembly 300. For installation purposes, it is preferable to have the fitting assembly fabricated from a similar material to the tubing that will be attached to the assembly. This allows the assembly to be installed into the steam distillation apparatus using soldering or welding techniques. Fitting assembly 300 is preferably fabricated from a material that is corrosion-resistant and heat-resistant (250°F). Additionally, the material preferably allows for a fluid-tight connection when the assembly is installed. For applications where the source and discharge waters are highly concentrated, such as seawater, fitting assembly 300 may be fabricated from, but is not limited to, copper-nickel or titanium.

[0064] Referring again to FIG. 3 , the first connector 302 includes a first end 304 and a second end 306. The first end 304 attaches to the heat exchanger 200 as shown in FIGS. 2-2A . The connector may be attached to the heat exchanger 200 by fastening the outer tube 202 to the exterior surface of the first end 304 of the connector 302 using a hose clamp. The inner tube 204 of the heat exchanger 200 may also be connected to the connector 302 at the first end 304. These tubes are soldered to the heat exchanger side of the connector 302. Other attachment methods may include, but are not limited to, welding, press fit, mechanical fastening, or insert molding. See also FIGS. 3A-3B for a cross-sectional view of the fitting assembly 300.

[0065] Referring now to FIG. 3C, in this embodiment, the first end 304 of the connector 302 may have five ports. Three ports may be fluidly connected to each other, as shown in FIGS. 3D-E. This configuration may combine multiple product water streams into one flow. Multiple product water streams increase the amount of heat transfer from the product water to the source water, as there is more product water in the heat exchanger to provide thermal energy to the source water. The remaining ports are separate and provide fluid paths for the blowdown water and source water illustrated in FIGS. 3E-F. Alternative embodiments may not have ports that are fluidly connected to each other.

[0066] 3C, connector 302 has a second end 306 for mating with second connector 310. This second end 306 may have three ports and provide paths for product water, source water, and blowdown water. The product flow path may include an extension 308. The extension 308 aids in assembling connectors 302 and 310 together because it allows for an O-ring groove in the body of second connector 310 rather than on the mating surface 310. Having an O-ring groove in the body of second connector 310 allows the flow paths through the connector assembly to be positioned near each other without having overlapping sealing areas.

[0067] Referring now to Figures 3G-H, the second connector 310 includes a first end 312 and a second end 314. The first end 312 mates with the first connector 302 as shown in Figure 3. This end may also include an extension 316 as shown in Figure 3G. The extension 316 allows the O-ring groove to be located within the body of the first connector 302 rather than within the surface of the end 306 of the first connector 302. Additionally, the connector may have a leak path 318 on the first end 312. This path is located around the product water port to prevent source water or blowdown water from entering the product stream. Blowdown water and source water may contain contaminants that affect the quality and safety of the product water. The leak path allows blowdown water and source water to exit the fitting rather than entering the product stream through the drain 320 shown in Figures 3G-I. In addition to the drain 320, the exemplary embodiment may include three independent fluid paths within the connector 310, illustrated in Figures 3I-J.

[0068] The first connector 302 may be assembled to the second connector 310 using a Marmon clamp to enable the device to be used. This type of clamp provides uniform clamping force and ease of disconnection / reassembly of the connection. Other methods of assembling the connectors together include, but are not limited to, using C-clamps or fasteners (i.e., bolts and nuts). Additionally, the circumference of the connectors 302 and 310 may be tapered, as shown in Figures 3E-F and 3I-J, to accept a clamp during installation of the fitting assembly 300. In other embodiments, the fitting assembly 300 may be permanently joined by welding or soldering the connectors together. (Evaporator / Condenser) 4-4B, an exemplary embodiment of an evaporator-condenser (also referred to herein as "evaporator / condenser") assembly 400 may consist of an evaporator / condenser chamber 402 having a top and a bottom. The chamber 402 may include a shell 410, an upper tube plate 414, and a lower tube plate 412. Attached to the lower tube plate 412 is a basin assembly 404 for holding incoming source water. Similarly, attached to the upper tube plate 414 is an upper flange 406. This flange connects a steam chamber 408 to the evaporator / condenser chamber 402. Within the evaporator / condenser chamber 402 are a plurality of rods 416, each surrounded by a tube 418, as illustrated in FIGS. 4A and 4B. The tubes 418 are in fluid communication with the basin 404 and the upper flange 406. See also FIG. 4C, which illustrates an alternative embodiment of an evaporator / condenser assembly 420.

[0069] Referring now to FIG. 5, basin assembly 500 (also identified as 404 in FIG. 4) may include an upper housing 502, a lower housing 504, a drain fitting 506, a drain 508, and a heating element 510. See also FIG. 5A for an exploded view of basin assembly 500 and FIG. 6 for a detailed view of upper housing 502. Basin assembly 500 contains and heats source water as well as collects particulates carried by the source water. As the source water changes state from a fluid to a vapor, particulates are left behind and collected in basin assembly 500.

[0070] 5-5A, the basin assembly 500 may be made from materials that are corrosion-resistant and high-temperature resistant. Because the basin is exposed to high temperatures, moisture, and corrosive source water, corrosion-resistant materials are preferred. In an exemplary embodiment, the basin is made from stainless steel. In alternative embodiments, the basin may be made from RADEL® or other high-temperature plastic, along with alternative configurations for mounting the heating element 510. For applications where the source water may be highly concentrated, such as seawater, the basin assembly 500 may be made from, but is not limited to, titanium, copper-nickel, naval brass, or high-temperature plastic.

[0071] 5-5A, the source water may be heated using a heating element 510 in the water reservoir assembly 500. The heating element 510 raises the temperature of the source water during initial start-up of the water vapor distillation apparatus 100. This element provides additional heat energy to change the source water from a fluid to a vapor. In an exemplary embodiment, the heating element 510 may be a 120 volt / 1200 watt resistor-type electric heater.

[0072] 5-5A, the basin assembly 500 may include a bottom housing 504 with an angled underside to aid in the collection of particulates. The bottom housing 504 may have any angle sufficient to collect particulates in one area of ​​the housing. In an exemplary embodiment, the bottom housing 504 has an angled underside at 17 degrees. In other embodiments, the bottom housing 504 may have a flat bottom.

[0073] Still referring to FIGS. 5-5A , the exemplary embodiment may include a drain assembly consisting of a drain fitting 506 and a drain 508. The drain assembly provides access to the inside of the evaporator / condenser to remove particulate buildup without the need to disassemble the device. The drain assembly may be located near the bottom of the basin to reduce debris (particle buildup) on the evaporator / condenser's inner tubes. Debris is prevented by allowing for periodic removal of debris within the basin assembly 500. Fewer particles within the basin assembly 500 reduce the likelihood of particles flowing into the evaporator / condenser tubes. In the exemplary embodiment, the drain assembly is positioned to receive particulates from the angled underside of the bottom housing 504. The drain assembly may be attached to the bottom housing 504 and may be made of any corrosion- and heat-resistant material. In the exemplary embodiment, the drain fitting 506 is a flanged sanitary fitting fabricated from stainless steel. 73, a fluid path for the sump drain 7302 is shown. In some embodiments, the fluid path for the sump drain 7302 can be used to facilitate cleaning or flushing of the device 100. In some embodiments, the fluid path for the sump drain 7302 can be sealed from the ambient environment by, for example, a valve, but the seal is not limited to a valve. In some embodiments, the valve need not be a manual valve, but can be, for example, a differential valve controlled by a control system, and in some embodiments, cleaning and flushing can be at least partially automated.

[0074] 5-5A , the drain fitting 506 may have a drain pipe 508 attached. The drain pipe 508 provides a fluid path for particulates to travel from the drain fitting 506 and out of the evaporator / condenser assembly 400. The drain pipe 508 may be made of any material of preference, provided that the material is corrosion-resistant and heat-resistant and capable of being attached to the drain fitting 506. In the exemplary embodiment, the drain pipe 508 is made of stainless steel. The diameter of the drain pipe 508 is preferably sufficient to allow for the removal of particulates from the sump assembly 500. A larger diameter pipe is desirable because it is less likely that the drain pipe 508 will become clogged with particles while draining the sump assembly 500.

[0075] 7, an exemplary embodiment of an evaporator / condenser chamber 700 (also identified as 402 in FIG. 4) may include a shell 702 (also identified as 410 in FIGS. 4A-B), a lower flange 704 (also identified as 502 in FIG. 5 and 600 in FIG. 6), a lower tube plate 706 (also identified as 412 in FIGS. 4A-B), a plurality of tie rods 708, a plurality of tubes 710 (also identified as 418 in FIGS. 4A-B), an upper flange 712 (also identified as 406 in FIG. 4), and an upper tube plate 714 (also identified as 414 in FIGS. 4A-B). See also FIG. 7A for an assembly view of the evaporator / condenser chamber 700.

[0076] Still referring to FIG. 7 , the shell 702 defines an interior cavity through which thermal energy is transferred from the high-pressure steam to the source water. This heat transfer assists in the phase change of the source water from a fluid to steam. In addition, the heat transfer also causes the incoming steam to condense into product water. The shell 702 may be fabricated from any material having sufficient corrosion resistance and strength characteristics. In the exemplary embodiment, the shell 702 is fabricated from fiberglass. The shell preferably has an inner diameter sufficient to contain the desired number of tubes 710. Within the interior cavity of the shell are a plurality of tubes 710 having a surface area for transferring thermal energy from the high-pressure steam entering the chamber to the source water within the tubes 710.

[0077] 7, evaporator / condenser chamber 700 defines an interior cavity for condensation of high-pressure steam. Within this cavity are multiple tubes 710 that transfer thermal energy from the high-pressure steam to source water within the tubes as the steam condenses on the exterior surfaces of the tubes. As described in U.S. Patent Application Publication No. 2005 / 0183832 A1, entitled "Method and Apparatus for Phase Change Enhancement," published August 25, 2005, the contents of which are incorporated herein by reference, heat transfer through the tube walls causes the source water to undergo a phase change via a process called thin-film evaporation.

[0078] 7, within the evaporator / condenser tube 710, a Taylor bubble may be developed having an outer surface comprising a thin film in contact with the inner surface of the tube 710. As the Taylor bubble rises within the tube, it heats up, causing the fluid in the thin film to transform into a vapor within the bubble.

[0079] Referring now to FIG. 7B, evaporators typically operate in one of two modes: pool boiling mode or thin film mode. In thin film boiling, a thin film of fluid is generated on the inner wall of the tube, promoting heat transfer from the tube wall to the free surface of the fluid. The efficiency of the phase change is typically increased in thin film mode compared to pool boiling mode. FIG. 7B shows the difference in distillate production flow rate as a function of condenser pressure for pool boiling and thin film boiling under similar conditions for a typical evaporator. The bottom curve 70 corresponds to pool boiling, while the middle curve 75 corresponds to thin film boiling. As can be seen from these two curves, thin film boiling mode provides significantly higher efficiency than pool boiling mode. However, thin film boiling is more difficult to maintain than pool boiling. Thin film evaporation is typically achieved using equipment containing very small openings. This equipment can easily clog, especially if the feed fluid contains contaminants. Additionally, in thin film mode, the water level is typically maintained marginally above the top of the tubes in vertical tube evaporators. For this reason, the device may also be sensitive to movement and positioning of the device.

[0080] Referring again to FIG. 7 , in the exemplary embodiment, the tube 710 may have an outer diameter of 0.75 inches and be made of copper. In alternative embodiments, the tube 710 may be made of other materials, including, but not limited to, nickel-copper or other composite materials. In various other embodiments, the diameter of the tube may be different, i.e., smaller or larger. For possible applications where the source water may be seawater, the tube 710 may be made of a copper-nickel or titanium material. These materials have high corrosion resistance so as to maintain the heat transfer properties of the tube when exposed to highly concentrated source water, such as salt water. The diameter of the tube 710 may also vary depending on many variables. The diameter of the tube 710 may be limited by the inner diameter of the shell 702 and the desired amount of heat transfer efficiency. Another constraint may be usability. Smaller diameters are difficult to remove flakes from because the reduced diameter limits access to the inner surface of the tube wall. The length of tube 710 may be determined by the length of the interior cavity defined by the thickness of shell 702 and tube sheets 706 and 714. In an exemplary embodiment, tube 710 may extend beyond the edge of the tube sheets and into bottom flange 704 and top flange 712.

[0081] 8, in an exemplary embodiment, tube 800 (also identified as 710 in FIGS. 7A-B) has beads 802 near each end. The beads 802 prevent tube 800 from sliding through openings in lower tube plate 706 and upper tube plate 714.

[0082] Referring now to FIG. 9 , improved efficiency of phase change operation may be achieved by providing packing within the evaporator / condenser tubes 904. The introduction of such packing may allow the evaporator to exhibit some of the properties of the thin film mode due to interactions between the fluid, the packing, and the tubes 904. The packing may be any shaped material such that the material preferentially fills the volume of the tubes 904 near the longitudinal axis of the tubes versus the volume near the interior walls of the tubes. Such packing material serves to concentrate vapor near the walls of the tubes for efficient heat exchange. For example, in an exemplary embodiment, the packing may comprise rods 902. Each rod 902 may be any cross-sectional shape, including cylindrical or rectangular. The cross-sectional area of ​​each packing rod 902 may be any area that fits within the cross section of the tube. The cross-sectional area of ​​each rod 902 may vary along the length of the rod. A given rod 902 may extend the length of a given evaporator tube 904 or any portion thereof. The rod material is preferably hydrophobic and capable of repeated thermal cycling. In an exemplary embodiment, the rod 902 is made of glass-filled RYTON® or glass-filled polypropylene.

[0083] Still referring to FIG. 9 , each rod 902 may be positioned anywhere within the tube 904, including preferentially in the upper portion of the tube. In one specific embodiment, each rod is approximately half the length of the associated tube and is positioned approximately in the upper half of the tube. The top curve 80 in FIG. 7B shows the increase in boiling efficiency of thin film boiling for a typical evaporator in which the evaporator tubes contain packing material in the upper half of the tube. With such packing, the phase change efficiency is also advantageously sensitive to changes in the fluid level above the tube, the orientation of the tube relative to vertical, the supply pressure to the tube, and other operating parameters of the evaporator. In the exemplary embodiment, the rods 902 have approximately the same length as the tubes 904.

[0084] 9A , in an exemplary embodiment, the rod 902 may have multiple members 906 extending outward from the center of the rod 902 and along the longitudinal axis of the rod 902. These members 906 maintain the rod 902 in the center of the pipe 904 to create the most efficient flow path for the source water. Any number of members may be used, but preferably there are a sufficient number to maintain the rod 902 in the center of the pipe 904. In an alternative embodiment, the rod 902 may not have members 906. In an alternative embodiment, the rod 902 may be held in place within the pipe 904 by wrapping the rod 902 within a wire or cross-borehole within the rod 902 to assist in the installation of a pin that positions the rod 902 within the pipe 904.

[0085] Referring again to FIG. 7 , tube 710 (also identified as 800 in FIG. 8 and 904 in FIG. 9 ) is held in place by a pair of tube sheets 706 and 714. These sheets are secured to each end of shell 702 using tie rods 708. Tube sheets 706 and 714 have a number of openings that provide a path for source water to enter and exit tube 710. When tube 710 is installed in chamber 700, the openings in tube sheets 706 and 714 receive the ends of tube 710. Lower tube sheet 706 (also identified as 1002 in FIG. 10 ) is attached to the bottom of shell 702. See FIG. 10 for a detailed view of the lower tube sheet. Upper tube sheet 714 (also identified as 1004 in FIG. 10A ) is attached to the top of shell 702. See FIG. 10A for a detailed view of the upper tube sheet. Both tube sheets have similar dimensions, except that the upper tube sheet 714 has an additional opening located in the center of the sheet that provides an opening for high pressure steam to enter the evaporator / condenser chamber 700.

[0086] 7, in an exemplary embodiment, the upper tube sheet 714 and the lower tube sheet 706 may be fabricated from RADEL®, a material that has low creep, hydrolytic stability, thermal stability, and low thermal conductivity. Additionally, tube sheets fabricated from RADEL® may be formed by machining or injection molding. In alternative embodiments, the tube sheets may be fabricated from other materials, including, but not limited to, G10.

[0087] Still referring to FIG. 7 , the size of the openings in the tubesheets 706 and 714 for receiving the tubes 710 is determined by the outer diameter of the tubes 710. These openings must be large enough to accommodate the ends of the tubes 710 and contain a seal. Typically, an O-ring groove is provided in the tubesheets to receive an O-ring. This O-ring provides a watertight seal between the inner tubes 710 and the tubesheets 706 and 714. This type of seal also simplifies construction, facilitates the use of dissimilar materials in the evaporator / condenser, and allows the tubes 710 to move during repeated thermal cycles. This seal prevents product water from entering the sump 500 of FIG. 5 or source water from entering the chamber 700. In alternative embodiments, tubes 710 may be installed within openings in tubesheets 706 and 714 by using methods including, but not limited to, soldering, welding, press-fitting, adhesive (i.e., silicone, RTV, epoxy, etc.), brazing, or swaging, depending on the tubesheet material.

[0088] 10 , in an exemplary embodiment, O-ring grooves are located in tube sheets 1002 and 1004 at various depths. The different depths of the O-ring grooves allow tubes 710 to be positioned closer together because O-ring grooves from adjacent tubes do not overlap one another. Overlapping O-ring grooves do not provide a sufficient seal, and therefore each O-ring groove must be independent of other O-ring grooves in the tube sheet. As a result of varying the location of the O-ring grooves at different depths in the tube sheet, adjacent O-ring grooves do not overlap one another, allowing the tubes to be positioned closer together. Thus, having tubes 710 positioned closer to one another allows more tubes to be positioned in the evaporator / condenser chamber 700.

[0089] Referring again to FIG. 7 , tube sheets 706 and 714 are also secured to bottom flange 704 and top flange 712 using connecting rod 708. Bottom flange 704 (also identified as 502 in FIG. 5 and 600 in FIG. 6 ) connects sump 500 in FIG. 5 to evaporator / condenser chamber 700 in FIG. 7 . Additionally, bottom flange 704 provides a fluid connection for the feedstock in the sump to the inlets of tubes 710 located on lower tube sheet 706. Bottom flange 704 may be of any height, with preference provided that the height is sufficient to allow for even distribution of source water entering tubes 710. Typically, a flange having a height of 1 to 2 inches provides even distribution of source water into tubes 710. In alternative embodiments, the height of the flange may be greater to increase the sump's ability to collect particles.

[0090] Still referring to Figure 7, upper flange 712 (also identified as 1100 in Figure 11) provides a fluid connection between the outlet of tube 710 and steam chest 408 in Figure 4. In addition, upper flange 712 collects source water removed from the low-pressure steam as the steam passes through steam chest 408. This water is then transported out of the device through discharge port 1102 located in the side of upper flange 1100 in Figure 11.

[0091] 7, the bottom flange 704 and the top flange 712 may be made of any material having sufficient structural strength and corrosion and heat resistance. In one embodiment, the flanges may be made of RADEL®. In an exemplary embodiment, the flanges may be made of nickel-plated aluminum. In other embodiments, the bottom flange may be made of materials including, but not limited to, stainless steel, titanium, and copper-nickel.

[0092] Referring to FIGS. 7-7A, a plurality of openings are located near the outer edges of the bottom flange 704 and the top flange 712 to receive tie rods 708. These rods are arranged longitudinally on a bolt circle concentric with the shell 702 and along the periphery of the shell 702. The length of the tie rods 708 is determined by the length of the shell 702 and the thicknesses of the bottom tube plate 706, bottom flange 704, top flange 712, and top tube plate 714. The tie rods 708 may have threaded ends for receiving threaded fasteners on each end of the rod to secure the evaporator / condenser components together. Additionally, the tie rods 708 may be made of any material that is strong enough for the purpose, such as stainless steel. The tie rods 708 may also be made of other materials, including, but not limited to, bronze, titanium, fiberglass composite, and carbon steel. In an exemplary embodiment, the connecting rod 708 may have flats machined near each end to provide a flat surface for receiving a device that holds the rod in place during installation.

[0093] 12-12C, a steam chamber 1200 (also identified as 408 in FIG. 4) may be connected to the upper flange 1100 (also identified as 712 in FIG. 7). In an exemplary embodiment, the steam chamber 1200 may include a base 1202, a steam separator assembly 1204, a cap 1206, and a steam pipe 1208. The base 1202 defines an interior cavity for receiving low-pressure steam generated within the tube 710 of the evaporator region of the evaporator / condenser chamber 700. The base 1202 may have any height to allow sufficient space to allow water droplets contained within the steam to separate. The height of the steam chamber allows water droplets carried by the steam and forced out of the outlet of the tube 710 by the rapid release of steam bubbles to slow down and retreat toward the upper flange 712 (also identified as 1100 in FIG. 11).

[0094] Still referring to FIGS. 12-12C , within base 1202 may be steam separator assembly 1204. This assembly consists of a basket and a screen (not shown in FIGS. 12-12C ). The basket contains a quantity of wire mesh. In the exemplary embodiment, steam separator assembly 1204 removes water droplets from incoming low-pressure steam by manipulating the steam through layers of wire mesh. As the steam passes through the screen, water droplets begin to collect on the surface of the screen. These water droplets may contain contaminants or particulates. As the water droplets increase in size, the water falls to the bottom of the basket. Multiple openings may be located at the bottom of the basket to allow water to collect within top flange 712. Additionally, these openings provide a fluid path for low-pressure steam to enter steam separator assembly 1204. Additionally, the wire mesh provides a barrier from splashing out water located within the evaporator / condenser top flange 712.

[0095] Still referring to FIGS. 12-12C , in an alternative embodiment, the steam separator assembly 1204 may contain a series of plates for collecting water droplets from low-pressure steam as the steam passes through or around each plate. The plates manipulate the steam, causing the water droplets to collect on the plates. The water is collected on the assembly because the plates are positioned to create sharp bends in the steam's flow path. These bends reduce the steam's velocity and change its direction. Momentum allows the water droplets to continue along their initial trajectory. The water droplets may then impact the walls or plates of the assembly where they collect. When enough water droplets collect on the walls or plates of the assembly, the water droplets may fall toward the top flange 406 of the evaporator / condenser.

[0096] 12-12C, the base 1202 may also have an observation window 1210. This window allows people operating the device to visually observe the interior of the steam chest to determine if the device is functioning properly. In other embodiments, the steam chest 1200 may not include an observation window 1210. This alternative embodiment is illustrated in FIG. 12D. In still other embodiments, the size and shape of the window may vary. In some embodiments, the steam chest may include multiple windows.

[0097] In an exemplary embodiment, the steam separator assembly may be fabricated from stainless steel. However, other materials may be used depending on the preference for corrosion resistance and high temperature resistance of the material. Other types of materials may include, but are not limited to, RADEL®, titanium, copper-nickel, plated aluminum, fiber composites, and high temperature plastics.

[0098] 12-12C , attached to the base 1202 is a cap 1206. The cap and base define an internal cavity for separating water from low-pressure steam. Additionally, the cap 1206 may have two ports, an outlet port 1211 and an inlet port 1212, shown in FIGS. 12B, 12E, and 12F. The outlet port provides a fluid path for dry, low-pressure steam to exit the steam chest 1200. In the exemplary embodiment, the outlet port 1211 is located near the top surface of the cap 1206 to promote drier steam by positioning the port away from the outlet of the evaporator / condenser tube 710. However, in alternative embodiments, the outlet port 1211 may have a different location within the cap 1206. Similarly, the inlet port 1212 provides a fluid path for high-pressure steam to enter the high-pressure steam tube 1208 within the steam chest 1200. In the exemplary embodiment, the inlet port 1212 is located near the top surface of the cap 1206. In alternative embodiments, the inlet port 1212 may have a different location within the cap 1206. In the exemplary embodiment, the cap 1206 is fabricated from plated aluminum. Other types of materials may include, but are not limited to, stainless steel, plastic, titanium, and copper-nickel. The size of these ports may affect the pressure drop across the compressor.

[0099] 12-12C , a steam pipe 1208 is connected to an inlet port 1212 in the steam chest 1200. This pipe provides a fluid path for high-pressure steam to pass through the steam chest and enter the condenser of the evaporator / condenser chamber. The inner diameter of the steam pipe 1208 may be any size so long as the pipe does not adversely affect the flow of high-pressure steam from the regenerative blower to the evaporator / condenser chamber. In an exemplary embodiment, the steam pipe 1208 may be made of stainless steel. Other materials may be used to manufacture the steam pipe 1208, but these materials must have sufficient corrosion and high-temperature resistance. Such materials may include, but are not limited to, plated aluminum, plastic, titanium, and copper-nickel. For applications where the source water may be highly concentrated, such as seawater, the steam chest 1200 may be made of, but is not limited to, titanium, nickel, bronze, nickel-copper, and copper-nickel.

[0100] 13-13C, an alternative embodiment of an evaporator / condenser assembly 1300 is shown. In this embodiment, the evaporator / condenser assembly 1300 includes a water sump 1302, an evaporator / condenser chamber 1304, a mist eliminator assembly 1306, a plurality of connecting rods 1308, a bottom flange 1310, and a top flange 1312. For a detailed view of the evaporator / condenser assembly without the water sump 1302, see FIG. 13D.

[0101] 13E, the evaporator / condenser chamber includes a shell 1314, a plurality of tubes 1316, a bottom flange 1310, and a top flange 1312. The evaporator / condenser chamber 1304 defines an interior cavity for condensation of high-pressure steam. The tubes 1316 transfer thermal energy from the high-pressure steam to the source water within the tubes as the steam condenses on the outer surface of the tubes 1316. In this embodiment, the tubes 1316 have an outer diameter of 0.75 inches and may be made of copper. In alternative embodiments, the tubes 1316 may be made of other materials, including, but not limited to, nickel copper or other composite materials. The diameter of the tubes 1316 may also vary depending on many variables. See the previous discussion in exemplary embodiments regarding tube diameters. The length of the tube 1316 may be determined by the length of the cavity defined by the shell 1314 and the thickness of the bottom flange 1310 and top flange 1312 .

[0102] 13E , the tubes 1316 are supported within an interior cavity defined by the shell 1314 by a lower flange 1310 and an upper flange 1312, as shown in FIGS. 13B, 13C, and 13E. Each flange has a plurality of openings axially located around the center of the flange. These openings may contain the ends of the tubes 1316. In addition, the lower flange 1310 and the upper flange 1312 also secure the shell 1314 in place and provide a path to the water reservoir 1302 and the mist eliminator assembly 1306. As the source water fills the water reservoir 1302, some water begins to fill the tubes 1316 located within the interior cavity of the shell 1314. As thermal energy is transferred to the source water in the tubes 1316, the water begins to evaporate. The source water vapor travels through the tubes 1316 and into the mist eliminator assembly 1306. Steam enters the mist eliminator through openings located in the top flange 1312 .

[0103] 13E , the shell 1314 is secured to the bottom flange 1310 and the top flange 1312 using a number of tie rods 1308. These tie rods are disposed axially outward around the circumference of the shell 1314. In addition, the tie rods 1308 also secure the mist eliminator 1306 to the top flange 1312 and the sump 1302 to the bottom flange 1310. The length of the tie rods is determined by the length of the shell 1314 and the thicknesses of the bottom flange 1310, the top flange 1312, the sump 1302, and the mist eliminator 1306. The tie rods 1308 may have threaded ends for attaching threaded fasteners on each end of the rod to secure the evaporator / condenser components together. Additionally, the tie rods 1308 may be fabricated from any material of sufficient strength, such as stainless steel. The connecting rod 1308 may be made from other materials including, but not limited to, bronze, titanium, fiberglass composite, and carbon steel.

[0104] 13E, in an exemplary embodiment, the shell 1314 is fabricated from fiberglass. Other materials may be used, with preference given that the material is corrosion resistant, has low thermal conductivity, and sufficient structural strength to withstand the internal pressures developed during operation of the evaporator / condenser assembly 1300. See the discussion of the exemplary embodiment regarding the size of the shell's inner diameter.

[0105] Referring again to FIG. 13E , the sump 1302 is connected to the bottom flange 1310 and is in fluid communication with the tubes 1316 of the evaporator / condenser assembly chamber 1304. The sump 1302 collects incoming source water from the heat exchanger. The source water enters the sump 1302 through an inlet port located in the sidewall of the sump. In other embodiments, the inlet port may be located in a different location (i.e., at the bottom). In this embodiment, the sump 1302 is made of a composite material, such as G10 plastic. In other embodiments, the sump 1302 may be manufactured from any other material that has sufficient corrosion resistance and high temperature resistance. Other materials include, but are not limited to, aluminum, RADEL®, and stainless steel. The sump 1302 may also include a heating element to provide thermal energy to the source water. This thermal energy helps the source water change from a fluid to a steam.

[0106] 14-14C, attached to the upper flange 1312 is a mist eliminator assembly 1400 (also identified as 1306 in FIG. 13). This assembly may consist of a cap 1402, a steam pipe 1404, and a mist eliminator 1406, as illustrated in FIG. 14. The cap 1402 contains low-pressure steam generated from the evaporator of the evaporator / condenser. The cap 1402 may have three ports 1408, 1410, and 1412, as shown in FIGS. 14A-C. See the discussion of the steam chest in the exemplary embodiment regarding the volume height for removing water droplets. Additionally, the cap 1402 defines a cavity that contains the mist eliminator 1406, as shown in FIGS. 14, 14C, and 14D.

[0107] Referring again to FIGS. 14-14C , a first port 1408 may be centrally located on the top surface of the cap 1402 for receiving a first end of a steam pipe 1404. This port allows high-pressure steam generated by the compressor to re-enter the evaporator / condenser through the first end of the steam pipe 1404. The steam pipe 1404 provides a fluid path for high-pressure steam to pass through the mist eliminator assembly 1400 and enter the evaporator / condenser without mixing with the low-pressure steam entering the mist eliminator assembly 1400. In this embodiment, the steam pipe 1404 is fabricated from stainless steel. In other embodiments, the steam pipe may be fabricated from materials including, but not limited to, plated aluminum, RADEL®, copper-nickel, and titanium. The length of the steam pipe 1404 should be sufficient to connect with the compressor and pass through the entire mist eliminator assembly 1400. The second end of the steam pipe is received within a centrally located port in the top flange 1312. The inner diameter of the steam pipe 1404 may affect the pressure drop across the compressor. Another effect on the system is that the steam pipe 1404 reduces the effective volume in the mist eliminator to remove water droplets from the low pressure steam.

[0108] Still referring to FIGS. 14-14C , the steam pipe 1404 may also have multiple external grooves for receiving mist eliminators 1406. The mist eliminators 1406 are annular plates with openings that allow low-pressure steam to pass through the plates. In one embodiment, multiple mist eliminators are installed within the grooves of the steam pipe 1404. The plates are oriented so that the openings are 180° from the previous plate. Additionally, the plate closest to the outlet port 1410 is oriented so that the opening is 180° from the port. In an alternative embodiment, the plates may include grooves on their upper surfaces to collect water droplets. These grooves may be tapered to allow collected water to flow away from the plate and fall toward the base of the mist eliminator assembly 1400. The mist eliminators 1406 may be secured to the steam pipe 1404 using a pair of snap rings and wave washers.

[0109] 14-14C, a second port 1410 may also be located on the top surface of the cap 1402 to allow dry low-pressure steam to exit the mist eliminator assembly 1400. See the previous discussion for example embodiments regarding the size and location of the exit port.

[0110] 14-14C, a third port 1412 may be located in the sidewall of the cap 1402. This port allows water removed from the low-pressure steam to exit the apparatus. The port is preferably located at a height that allows the blowdown water to exit the mist eliminator assembly 1400 without excessive buildup of blowdown water within the assembly. Additionally, the height of the port is preferably not too low, but rather sufficient to maintain a level of blowdown water covering the outlet of the tube. In an exemplary embodiment, a tube may be connected to the port 1412, and the blowdown water may pass through the level sensor housing 108 and the heat exchanger 102 before exiting the apparatus 100.

[0111] 14-14C, the mist eliminator assembly 1400 may be fabricated from any material having sufficient corrosion resistance and high temperature resistance. In this embodiment, the mist eliminator assembly is fabricated from stainless steel. The assembly may also be fabricated from other materials, including, but not limited to, RADEL®, stainless steel, titanium, and copper-nickel. (Compressor) The water vapor distillation apparatus 100 may include a compressor 106. In the exemplary embodiment, the compressor is a regenerative blower. While other types of compressors may be implemented, for purposes of this application, a regenerative blower is shown and described with respect to the exemplary embodiment. The purpose of the regenerative blower is to compress low-pressure steam exiting the evaporator section of the evaporator / condenser to produce high-pressure steam. Increasing the steam pressure increases the steam's temperature. This temperature increase is desirable because as the high-pressure steam condenses on the tubes in the condenser section of the evaporator / condenser, heat energy is transferred to the incoming source water. This heat transfer is important because the heat energy transferred from the high-pressure steam supplies the low-pressure steam to the regenerative blower.

[0112] The pressure change between low-pressure steam and high-pressure steam is determined by the desired output of product water. Product water output is related to the flow rate of high-pressure steam. If the steam flow rate of high-pressure steam from the compressor to the condenser section of the evaporator / condenser is greater than the condenser's capacity to accept the steam, the steam may be superheated. Conversely, if the evaporator side of the evaporator / condenser produces more steam than the compressor can compress, the condenser side of the evaporator / condenser may not operate at full capacity due to the limited flow rate of high-pressure steam from the compressor.

[0113] Referring now to Figures 15-15G, an exemplary embodiment may include a regenerative blower assembly 1500 for compressing low-pressure vapor from the evaporator section of an evaporator / condenser. The regenerative blower assembly 1500 includes an upper housing 1502 and a lower housing 1504 that define an interior cavity, as illustrated in Figure 15C. For detailed views of the upper housing 1502 and the lower housing 1504, see Figures 15D-G. An impeller assembly 1506 is located within the interior cavity defined by the upper housing 1502 and the lower housing 1504. The housing may be manufactured from various plastics, including RYTON®, ULTEM®, or polysulfone. Alternatively, the housing may be manufactured from materials including, but not limited to, titanium, copper-nickel, and aluminum-nickel-bronze. In the exemplary embodiment, the upper housing 1502 and the lower housing 1504 are manufactured from aluminum. In alternative embodiments, other materials may be used, with the preference that the material be high temperature and corrosion resistant, not absorb water, and have sufficient structural strength. The housing is preferably sized sufficiently to accommodate the impeller assembly and associated internal passages. Additionally, the housing preferably provides sufficient clearance between the stationary housing and the rotating impeller to avoid sliding contact and prevent leakage from occurring between the two stages of the blower. In addition to the clearance, the upper housing 1502 and the lower housing 1504 may be mirror images of each other.

[0114] 15D-F, the upper and lower housings 1502, 1504 may have an inlet port 1510 and an outlet port 1512. Low-pressure steam from the evaporator / condenser enters the blower assembly 1500 through the inlet port 1510. In the exemplary embodiment, the inlet port is shaped to create a spiral flow around the annular flow channel of the upper and lower housings 1502, 1504. After compressing the low-pressure steam, the high-pressure steam exits through the outlet port 1512. A clearance is reduced between the inlet port 1510 and the outlet port 1512 of the upper and lower housings 1502, 1504 to prevent mixing of the high-pressure steam exiting the blower assembly and the low-pressure steam entering the assembly. The exemplary embodiment may include a stripper plate 1516. In this plate, open flow channels provided in the upper and lower housings 1502, 1504 allow only high pressure steam present in the impeller blades to pass through the area near the inlet port 1510, referred to as the inlet region.

[0115] 15D-F, carryover of high-pressure steam into the inlet region through the stripper plate 1516 may irreversibly mix with the incoming low-pressure steam entering the blower assembly 1500 from the inlet port 1510. The mixing of the steam may cause an increase in the temperature of the incoming low-pressure steam. The carryover of high-pressure steam may also block the inflow of low-pressure steam due to the expansion of the high-pressure steam in the inlet region. Pressure-reducing conduits 1514 in the upper and lower housings 1502, 1504 may extract compressed steam trapped in the impeller blades and release the steam into the inlet region to block the incoming low-pressure steam.

[0116] 15D-F, the distance between the inlet port 1510 and the outlet port 1512 is controlled by the size of the stripper plate 1516. In an exemplary embodiment, the stripper plate area is optimized to reduce the amount of high pressure steam carryover into the inlet region and maximize the working flow channels within the upper and lower housings 1502, 1504.

[0117] 15H-K, in an exemplary embodiment, the shaft 1514 is supported by a pressurized water-fed bearing 1516 that is pressed into the impeller assembly 1506 and supported by the shaft 1514. In this embodiment, the bearing may be made of graphite. In alternative embodiments, the bearing may be made of materials including, but not limited to, Teflon composites and bronze alloys.

[0118] 15H-K, while water may enter the compression chamber of the blower assembly 1500, the water supplied to the pressurized water supply bearing 1516 is preferably clean water. If water enters the compression chamber, it will likely mix with pure steam. Contaminated water mixing with pure steam results in contaminated high-pressure steam. In an exemplary embodiment, product water is supplied to the bearing.

[0119] Hydrodynamic lubrication is desired for the high-speed blower bearing 1516 of the exemplary embodiment. In hydrodynamic operation, the rotating bearing rides on a film of lubricant and does not contact the stationary shaft. This mode of lubrication provides the lowest coefficient of friction, and because there is no physical contact of the components, wear is essentially nonexistent.

[0120] Operation in other lubrication conditions, such as mixed film lubrication and boundary lubrication, results in higher power losses and higher wear rates than hydrodynamic operation. In exemplary embodiments, the blower may operate with hydrodynamic lubrication, film lubrication, or a combination of both. The running clearance between the rotating bearing and the stationary shaft, the rotational speed of the bearing, and the lubrication fluid pressure and flow may affect the bearing lubrication mode.

[0121] 15H-K, in hydrodynamic bearings, the limiting load rate may be affected by heat dissipation capabilities. Compared to unlubricated (or boundary lubricated) bearings, hydrodynamic bearings have additional mechanisms for dissipating heat. The most effective heat dissipation method for hydrodynamic bearings is to allow the lubricating fluid to carry away thermal energy. In an exemplary embodiment, bearing supply water removes thermal energy from the bearing 1516. In this embodiment, the volume of water flowing through the bearing is preferably sufficient to maintain the bearing temperature within operational limits. Additionally, diametric clearances may be varied to control the flow rate of the bearing supply water, but these clearances are preferably not so large as to create hydrodynamic pressure losses.

[0122] 15H-K, the amount of bearing feed water supplied to bearings 1516 is preferably sufficient to maintain hydrodynamic lubrication. Excessive bearing feed water can have adverse effects on blower assembly 1500. For example, excess water can quench the high-pressure steam, unnecessarily reducing the thermal efficiency of the device. Another adverse effect of excess bearing feed water is that it can be expelled outward from the impeller assembly, causing power loss due to shearing of the water as it is forced between the housing wall and passing impeller blades.

[0123] Referring to FIG. 15L, in the exemplary embodiment, a bearing feed water return 1526 is provided in the blower to prevent excess bearing feed water from entering the impeller buckets.

[0124] 15H-K, in an exemplary embodiment, the bearing feed water pump maintains a pressure of 2-5 psi for the input to the pressurized water supply bearing 1516. The flow rate of the bearing feed water may be maintained by having a constant bearing feed water pressure. In an exemplary embodiment, the bearing feed water pressure may be controlled to ensure a constant flow rate of the bearing feed water to the bearing 1516.

[0125] 15H-K, in an exemplary embodiment, the impeller assembly may be driven by a motor using a magnetic drive linkage rather than a mechanical seal. The lack of a mechanical seal eliminates the friction losses associated with moving parts that contact each other. In this embodiment, the magnetic drive linkage may include an inner rotor magnet 1518, a containment shell 1520, an outer magnet 1522, and a drive motor 1508.

[0126] 15H-K, the inner magnet rotor 1518 may be embedded within a cup. In an exemplary embodiment, the magnets are axially disposed. In other embodiments, the axial direction may be radially disposed. The cup may be made of a plastic or metal material. In some embodiments, the cup material may be, but is not limited to, RYTON®, ULTEM®, or polysulfone. Similarly, the magnets may be made of materials including, but not limited to, ferrite, aluminum-nickel-cobalt, samarium-cobalt, and neodymium-iron-boron. In an exemplary embodiment, the cup is attached to the impeller assembly 1500. In an exemplary embodiment, the cup is press-fit onto the shaft 1514. Other methods of attaching the cup may include, but are not limited to, splines and set screws.

[0127] 15H-K, a magnetic coupling shell 1520 is positioned between the inner rotor magnet 1518 and the outer rotor magnet 1522. The magnetic coupling shell 1520 is a pressure vessel or containment shell for the blower assembly 1500. This shell seals the vapor being compressed within the blower assembly 1500 and prevents the vapor from leaking into the surrounding environment.

[0128] 15H-K, because the shell 1520 is located between the inner rotor magnet 1518 and the outer rotor magnet 1522, eddy current losses may occur. If the shell 1520 were conductive, the rotating magnetic field could cause current to flow through the shell, resulting in power losses. Conversely, to reduce the amount of eddy current losses, a shell 1520 fabricated from a highly electrically resistive material is preferred. In an exemplary embodiment, titanium may be used to fabricate the magnetic coupling shell 1520. This material offers a combination of high electrical resistance and corrosion resistance. Corrosion resistance is preferred due to the potential for contact between the bearing feedwater and the shell 1520. In other embodiments, the shell 1520 may be fabricated from a plastic material with higher electrical resistance and corrosion resistance. In these alternative embodiments, the shell 1520 may be fabricated from materials including, but not limited to, RYTON®, ULTEM®, polysulfone, and PEEK.

[0129] 15H-K, the outer rotor magnet 1522 may be connected to a drive motor 1508. This motor rotates the outer rotor magnet 1522, which in turn rotates the inner rotor magnet, allowing the impeller assembly 1506 to compress low-pressure steam within the cavity defined by the upper and lower housings 1502, 1504. In an exemplary embodiment, the drive motor may be an electric motor. In an alternative embodiment, the drive may be, but is not limited to, an internal combustion or Stirling engine.

[0130] 15H-K, the blower assembly 1500 may be configured as a two-stage blower or a two-stage blower. In two-stage operation, incoming low-pressure steam from the evaporator side of the evaporator / condenser is simultaneously fed to both inlet ports of the blower's two separate stages. The first stage may be at the bottom between the lower housing 1504 and the impeller assembly 1506, and the second stage may be at the top between the upper housing 1502 and the impeller assembly 1506. As the impeller assembly 1506 rotates, incoming low-pressure steam from the inlet ports 1510 of both stages is simultaneously compressed, and high-pressure steam exits through the outlet ports 1512 of the upper housing 1502 and the outlet ports 1512 of the lower housing 1504.

[0131] 15H-K, in contrast, a two-stage blower has two distinct compression cycles. During the first compression cycle, low-pressure steam from the evaporator of the evaporator / condenser is supplied to the inlet 1514 of the lower housing. Compressed steam from the first stage exits through the outlet port 1516 of the lower housing and is supplied to the inlet port 1510 of the upper housing 1502. This steam, compressed in the first stage, is compressed again during the second stage. After the second compression cycle, the steam can exit the blower assembly 1500 at an increased pressure through the outlet port 1512 of the upper housing 1502.

[0132] For a given blower design, both two single-stage blowers and two-stage blower configurations have unique pressure-flow curves. These curves show that two single-stage blowers generate a higher steam flow rate compared to a two-stage blower, which generates a higher pressure differential. Based on the system operating differential pressure, the blower flow rate and efficiency depend on the blower's flow characteristics. Depending on the differential pressure across the blower assembly 1500, one configuration may be preferable over another. In the exemplary embodiment, the blower assembly 1500 has a two single-stage blower configuration.

[0133] 16-16A, within the interior cavity defined by the upper and lower housings 1502 and 1504 is an impeller assembly 1600 (also identified as 1506 in FIG. 15). The impeller assembly 1600 includes a plurality of impeller blades on each side of the impeller 1602 and a spindle 1604. In an exemplary embodiment, the impeller 1602 may be manufactured from Radel®, and the impeller spindle 1604 may be manufactured from aluminum. In alternative embodiments, these components may be manufactured from materials including, but not limited to, titanium, PPS, and ULTEM®. Other materials may be used to manufacture these components, with the preference being that these materials are resistant to high temperatures and do not absorb water. Additionally, the impeller spindle 1604 may have passages for returning bearing feed water to the sump. These passages prevent the bearing feed water from entering the impeller buckets.

[0134] Still referring to Figures 16-16A, the blades are designed on each side of the periphery of the impeller 1602 to create a series of spiral flows as the impeller rotates. This flow causes steam to repeatedly pass through the blades for additional energy as it flows through the open annular channel. The number of blades and bucket volume may be designed to optimize the desired flow rate and pressure differential. The number of blades and bucket volume are inversely proportional to each other, so increasing the number of blades creates a higher pressure differential but a lower flow rate. The labyrinth grooves on the periphery of the impeller 1602 prevent steam leakage across stages of the blower assembly 1500, thereby increasing blower efficiency.

[0135] 15H-K, the shaft 1514 is attached to and stationary within the upper and lower housings 1502, 1504. In an exemplary embodiment, the shaft 1514 may be made of titanium. In other embodiments, the shaft 1514 may be made of materials including, but not limited to, aluminum oxide, silicon oxide, or titanium, as well as stainless steel with coatings for increased wear and corrosion resistance. Additionally, the shaft 1514 may have passages that carry bearing supply water to the shaft 1516.

[0136] 15H-K, the two-stage blower configuration of the blower assembly 1500 may generate a downward axial thrust force. This force is generated because the second stage at the top of the impeller assembly 1506 is at a higher pressure compared to the first stage at the bottom of the impeller assembly 1506. In an alternative embodiment, this thrust force may be balanced by an equal and opposite magnetic force generated by offsetting the inner rotor magnet 1518 and the outer rotor magnet 1522. This configuration prevents excessive wear on the thrust surface of the lower pressurized water supply bearing 1516.

[0137] 17-17E, an alternative regenerative blower embodiment 1700 is shown. This embodiment may include an impeller housing assembly 1702, a mounting plate 1704, and a mounting flange 1706. See Figures 17B-D for a cross-sectional view of the regenerative blower assembly 1700. See also Figure 17E for an exploded view of the regenerative blower assembly 1700.

[0138] 17-17E, a mounting plate 1704 connects a mounting flange 1706 to the impeller housing assembly 1702. The mounting plate also provides ports that provide fluid passage into the lower housing 1708 of the impeller housing assembly 1702, as shown in FIG. 17E. In addition, the mounting plate provides a passage for bearing feed water to exit the blower assembly 1700.

[0139] 17F-I, impeller housing assembly 1702 may include a lower housing 1708, an impeller assembly 1710, and an upper housing 1712. Also see Figures 17H-I for cross-sectional views of impeller housing assembly 1702.

[0140] 17F-I, the lower housing 1708 and the upper housing 1712 define an internal cavity that contains the impeller assembly 1710. This cavity provides a volume for the impeller to compress incoming low-pressure steam. The steam may enter the impeller housing assembly through inlet ports located in the lower housing 1708 and the upper housing 1712. After the low-pressure steam is compressed by the impeller assembly 1710, the high-pressure steam may exit through outlet ports located in the lower housing 1708 and the upper housing 1712. See FIGS. 17J-K for a detailed view of the lower housing 1708. Additionally, the lower housing 1708 and the upper housing 1712 may be fabricated from, but are not limited to, aluminum, titanium, PPS, and ULTEM®.

[0141] 17F-I, the upper housing 1712 may include an access cover 1714 attached to the top surface of the housing. See FIG. 17L for a top view of the upper housing 1712 with the access cover 1714 installed. This cover allows access to ports located within the upper housing cover. See FIG. 17M, which provides a top view of the upper housing 1712 without the access cover 1714 installed. This view illustrates the inlet and outlet ports located within the upper housing 1712.

[0142] 17N, the lower housing 1708 and the upper housing 1712 may include, on the interior surface of the housing, a vacuum conduit 1716 and a strip plate 1718. These features perform similar functions as those described in the exemplary embodiment of the blower assembly 1500.

[0143] 18-18A, the interior cavity defined by the lower housing 1708 and the upper housing 1712 contains an impeller assembly 1800 (also identified as 1710 in FIG. 17). This assembly may include a spindle 1802 and an impeller 1804 having blades, as shown in FIGS. 18-18A. As low-pressure steam enters the interior cavity of the impeller housing 1702, the impeller assembly 1800 compresses the steam as the assembly is rotated.

[0144] 18-18A, a drive motor provides rotational energy to rotate the impeller 1804 and blades. Bearings 1716 may be located between the inner surface of the spindle and the shaft. These bearings support the shaft and allow the impeller 1804 to rotate freely. The bearings 1716 may be located near the end of the spindle 1802.

[0145] In an alternative embodiment of the apparatus, the low pressure vapor may be compressed using a liquid ring pump such as described in U.S. Patent Application Publication No. 2005 / 0016828A1, entitled "Pressurized Vapor Cycle Liquid Distillation," published January 27, 2005, the contents of which are incorporated herein by reference. (Level Sensor Assembly) 19, the exemplary embodiment of the water vapor distillation apparatus 100 may also include a level sensor assembly 1900 (also identified as 108 in FIG. 1), which measures the amount of product water and / or blowdown water produced by the apparatus 100.

[0146] 19-19A, an exemplary embodiment of a level sensor assembly 1900 may include a settling tank 1902 and a level sensor housing 1904. The settling tank 1902 collects particulates carried in the discharge water before the water enters the discharge level sensor tank 1912. The tank removes particulates from the discharge water by reducing the water's velocity as it flows through the tank. The settling tank 1902 defines an interior volume. The volume may be divided approximately in half by the use of a fin 1905 extending from the sidewall opposite the drain port 1908 in close proximity to the drain port 1908. This fin 1905 may extend from the bottom to the top of the volume. The discharge enters through the inlet port 1906 and must flow around the fin 1905 before the water may enter through the level sensing port 1910. As the discharge enters the body of the vessel, the velocity decreases due to the increased area. Any particles during release may settle out of suspension due to velocity reduction. The settling tank 1902 may be made of any material that is corrosion and heat resistant. In the exemplary embodiment, the housing is made of RADEL®. In alternative embodiments, the settling tank 1902 may be made of other materials, including, but not limited to, titanium, copper nickel, and stainless steel.

[0147] 19-19A , the settling tank 1902 may have three ports: an inlet 1906, a drain 1908, and a level sensor port 1910. The inlet port 1906 may be located in the top surface of the settling tank 1902, adjacent to the separation fins 1905 and opposite the drain port 1908, as shown in FIGS. 19A-B. This port allows blowdown water to enter the tank. The drain port 1908 may be located in the bottom of the settling tank 1902, as shown in FIGS. 19A-B. The drain port 1908 provides access to a reservoir to facilitate removal of particulates from the tank. In an exemplary embodiment, the bottom of the tank may be sloped toward the drain, as shown in FIG. 19B. The level sensor port 1910 may be located in the top surface of the tank, adjacent to the separation fins 1905 but opposite the inlet port 1906, as shown in FIG. 19A. This port provides a fluid path to the blowdown level sensor reservoir 1912. A fourth port is not shown in Figure 19A. This port allows blowdown water to exit the level sensor assembly 1900 and enter the heat exchanger. This port is located inside one of the side walls of the top half of the settling tank 1902 and away from the inlet port 1906.

[0148] 19-19A, in an exemplary embodiment, a strainer may be installed in the flow path of the blowdown water after it exits the blowdown level sensor reservoir 1912 and the settling tank 1902. The strainer may collect large particulates while allowing the blowdown water to flow to other system components. The strainer may be made of a corrosion-resistant material. In an exemplary embodiment, the strainer is fabricated from stainless steel. Additionally, the filter element may be removable to aid in cleaning the element. The strainer removes particulates from the blowdown water and limits the amount of particulates that enter the heat exchanger. Excessive particulates in the blowdown water can clog the inner tubes of the heat exchanger with scale and deposits, reducing the efficiency of the heat exchanger. Additionally, particulates can create blockages that impede the flow of blowdown water through the heat exchanger.

[0149] 19-19A , the settling tank 1902 is fluidly connected to a level sensor housing 1904. This housing may have three internal reservoirs, including, but not limited to, a discharge level sensor reservoir 1912, a product level sensor reservoir 1914, and a bearing feed water reservoir 1916. The discharge level sensor reservoir 1912 is separate from the other reservoirs to prevent contaminants from mixing with the discharge water. The level sensor housing 1904 may be manufactured from any material that is corrosion-resistant and heat-resistant. In the exemplary embodiment, the housing is manufactured from RADEL®. In other embodiments, the housing may be manufactured from other materials, including, but not limited to, titanium, copper-nickel, and stainless steel. In other embodiments, the ball float may have a 45-degree range of motion, and the housing may be shaped differently depending on the preference for a constant change in fluid level volume during this movement.

[0150] Still referring to FIGS. 19-19A , within the level sensor housing 1904 is a discharge level sensor reservoir 1912. This reservoir is fluidly connected to the settling tank 1902 via a measurement port 1910 located in the top surface of the tank 1902. The reservoir provides a location where the rate of blowdown water produced by the device may be measured using a level sensor 1918. As blowdown water fills the settling tank, some of the water flows through the measurement port 1910 and into the discharge level sensor reservoir 1912. Additionally, a vent port 1923 may be located within the top of the reservoir. This port allows air to escape from the reservoir, allowing the blowdown water to fill the cavity. The reservoir volume must be sufficient to maintain the water level. An enclosure with too small a volume may fill and drain quickly, adversely affecting the function of the level sensor. In contrast, a reservoir with a large volume may have a slower level sensor response time due to small fluid level height changes for a given increase or decrease in volume. A larger volume may also mitigate water level fluctuations generated by operation of the device. Referring now to FIG. 73 , a discharge drain 7300 fluid path may be included in and fluidly connected to the level sensor assembly. In some embodiments, the discharge drain 7300 fluid path may be used to facilitate cleaning or flushing of the device 100. In some embodiments, the discharge drain 7300 fluid path may be sealed from the ambient environment by, for example, a manual ball valve, although sealing is not limited to manual ball valves. In some embodiments, the valve may not be a manual valve, but may be, for example, a differential valve controlled by a control system, and in some embodiments, cleaning and flushing may be at least partially automated.

[0151] 19-19A, a product level sensor reservoir 1914 may be located next to the discharge level sensor reservoir 1912. The product level reservoir 1914 has an inlet port 1920 and an outlet port 1922. Product water enters the reservoir through the inlet port 1920 and exits the reservoir through the outlet port 1922. The outlet port 1922 may be located below the low end measurement point of the level sensor to improve water outflow from the reservoir. Similarly, the inlet port 1920 may be located below the low end measurement point of the level sensor to minimize disruption caused by inflowing water. In an exemplary embodiment, the inlet port 1920 and the outlet port 1922 may be located on the side of the level sensor housing 1904, as shown in FIG. 19A. This reservoir provides space for measuring the rate of product being produced by the device. Additionally, a vent port 1923 may be located within the top of the reservoir. This port allows air to escape from the reservoir allowing product water to fill the cavity.

[0152] 19-19A, the product level sensor reservoir 1914 is fluidly connected to the bearing feedwater reservoir 1916. An external port 1924 provides a fluid path for product water to flow between the product level sensor reservoir 1914 and the bearing feedwater reservoir 1916, shown in FIG. 19C. Product water enters the bearing feedwater reservoir 1916 through the external port 1924. Additionally, the bearing feedwater reservoir 1916 has a supply port 1926 and a return port 1928, shown in FIG. 19C. The supply port 1926 provides a fluid path for lubricating the bearings in the regenerative blower assembly. Similarly, the return port 1928 provides a fluid path for product water to return from lubricating the bearings of the regenerative blower assembly. The supply and return ports may be located on the side of the level sensor housing 1904, as shown in FIG. 19C.

[0153] Still referring to FIGS. 19-19A , an optical level sensor may be installed to monitor the amount of product water in the bearing feedwater reservoir 1916. In an exemplary embodiment, the optical level sensor may be located approximately two-thirds of the way up in the bearing feedwater reservoir 1916. The sensor senses the presence of water in the reservoir, indicating there is enough water to lubricate the bearings. The sensor may also be installed by threading the sensor into the level sensor housing 1904. The sensor may include an O-ring to provide a watertight seal. In other embodiments, the sensor may be, but is not limited to, a conductivity sensor, a float switch, a capacitance sensor, or an ultrasonic sensor.

[0154] 19D-F, an alternative level sensor housing 1930 having two reservoirs is shown. Within the level sensor housing 1930 is a discharge level sensor reservoir 1932. This reservoir is similar to and serves the same function as the previously described discharge reservoir 1912 within the level sensor housing 1904. In contrast, here the product level sensor reservoir 1934 contains product water to supply the bearings of the regenerative blower. The bearing supply water reservoir 1916 of the level sensor housing 1904 is eliminated from this configuration. Instead, product water is drawn from the product level sensor reservoir to supply water for the regenerative blower.

[0155] 19D-19F, the product level sensor reservoir 1934 may have an inlet port 1935, an outlet port 1936, a return port 1938, and a supply port 1940. The inlet port 1935 allows product water to enter the reservoir. Similarly, the outlet port 1936 provides a fluid path for the product water to exit the housing. Additionally, the supply port 1940 allows the product water to exit the reservoir to lubricate the bearings of the regenerative blower. After passing through the bearings of the regenerative blower, the product water may re-enter the product level sensor housing through the return port 1938. While these ports may be located anywhere within the housing, locating the supply port 1940 and the return port 1938 near the bottom of the housing may limit adverse effects on the function of the level sensor.

[0156] 19G-H, a sensor 1942 may be positioned outside the level sensor housing 1904 to receive input from the level sensor assembly 1918. Upon receiving input from the level sensor assembly 1918, the sensor 1942 signals that the water level in the tank is within a particular range or at a particular level. In an exemplary embodiment, the sensor may be a continuous analog sensor. This type of sensor provides continuous feedback on the position of the level sensor assembly 1918. As a magnet within the level sensor changes position, a voltage change occurs that is measured and used to determine the location of the sensor. Other embodiments may include, but are not limited to, a Hall sensor or a reed switch. FIG. 19H illustrates one possible alternative embodiment of a level sensor assembly including a set of floating magnets 1944 and a position magnet 1946. The position magnet 1946 is attached to the side of the level sensor housing 1904.

[0157] 20-20A, within the discharge level sensor reservoir 1912 and the product level sensor reservoir 1914 are level sensors 2000 (also identified as 1918 in FIGS. 19A and 19E). These sensors may include a base 2002, an arm 2004, and a floating ball 2006.

[0158] 20-20A , an exemplary embodiment of level sensor 2000 may include a base 2002 that supports an arm 2004 and a floating ball 2006. The assembly also includes two magnets (not shown). The base is connected to the arm and floating ball assembly, and the assembly pivots on a small diameter shaft (not shown). In addition, base 2002 carries two magnets. These magnets are located 180 degrees from each other, on the surface of base 2002, and parallel to the pivot. Additionally, these magnets may be positioned coaxially with the pivot point within base 2002. In an exemplary embodiment, the magnets may be cylindrical magnets with an axial magnetization direction.

[0159] Still referring to FIGS. 20-20A , the level sensor 2000 measures the rotation of the arm and ball assembly relative to the pivot. In the exemplary embodiment, the maximum displacement angle is 45 degrees. In this embodiment, the level sensor is positioned to prevent the floating ball 2006 from being positioned directly below the pivot. In other embodiments, the maximum displacement angle may be as great as 80 degrees. The sensor may monitor the magnet through the wall of the housing. This configuration allows the sensor to be protected from corrosive water spills and to seal the level sensor housing. The base may be fabricated from any material that is corrosion-resistant, heat-resistant, and non-magnetic. In the exemplary embodiment, the base 2002 is fabricated from G10 plastic. In alternative embodiments, the base 2002 may be fabricated from other materials, including, but not limited to, RADEL®, titanium, copper-nickel, and fiberglass laminates.

[0160] 20-20A , attached to base 2002 is arm 2004. Arm 2004 connects base 2002 with floating ball 2006. In the exemplary embodiment, arm 2004 is made of G10 plastic material. Other materials may be used to manufacture arm 2004, depending on the preference for the material to have sufficient high temperature resistance. Other materials may include, but are not limited to, stainless steel, plastic, RADEL®, titanium, and copper-nickel. The length of the arm is determined by the size of the level sensor reservoir. Additionally, the exemplary embodiment has multiple openings located along and perpendicular to the longitudinal axis of the arm. These openings reduce the weight of the arm and allow it to be more sensitive to level changes.

[0161] Still referring to FIGS. 20-20A , a float ball 2006 is attached to the other end of the arm 2004. The float ball 2006 provides a surface area for contact with the water flow. The force applied to the float ball 2006 by the water causes the level sensor assembly 2000 to pivot about a small diameter axis. This change in the position of the arm indicates the amount of water in the device. The float ball may be made of any material that is corrosion-resistant and heat-resistant. Additionally, the material preferably has a low water absorption rate. In the exemplary embodiment, the float ball is made of hollow stainless steel. For applications where the source water is highly concentrated, such as seawater, the float ball 2006 may be made of any highly corrosion-resistant material, including, but not limited to, plastic, titanium, and copper-nickel. Furthermore, the float ball 2006 is preferably appropriately sized to be placed within the level sensor housing 1904 so that it can move freely. Additionally, the size of the float ball 2006 is determined by the size of the level sensor reservoir.

[0162] Referring now to FIGS. 21-21A, a bearing feedwater pump 2100 (also identified as 110 in FIGS. 1-1A) may be connected to the supply port 1926 of the bearing feedwater reservoir 1916. The pump 2100 allows product water to flow from the bearing feedwater reservoir 1916 to the regenerative blower. In an exemplary embodiment, the flow rate is 60 ml / min, and the pressure ranges from 2 psi to 2.5 psi. Any type of pump may be used, provided that the pump can provide sufficient volume to maintain proper lubrication flow to the bearings in the regenerative blower. Additionally, the pump 2100 is preferably heat-resistant to withstand the high temperatures of the surrounding environment and the hot product water passing through the pump. In an exemplary embodiment, the bearing feedwater pump 110 is a GOTEC linear positive displacement pump, model number ETX-50-VIC. In alternative embodiments, other pump types, such as centrifugal pumps, may be used, provided that the pump is capable of operating at high temperatures. (Control equipment) The device may also include a manifold with multiple control valves for different water flow paths. Typically, the manifold will include a control valve in the inlet piping for the source water to control the amount of water entering the device. Because excessive pressure can cause the control valve to fail to open or fail to close once opened, a regulator may be included in the inlet piping to regulate the pressure of the source water.

[0163] Similarly, the manifold may also include a control valve in the outlet piping that carries the blowdown water out of the device, which allows the operator to control the amount of blowdown water exiting the device.

[0164] The control manifold may also include a control valve in the product water outlet piping. This valve allows the operator to control the amount of product water exiting the device. In an exemplary embodiment, there is one control valve for each section of outlet piping. Similarly, the device includes a vent valve to release gaseous compounds from the evaporator / condenser. The vent valve maintains the device's operating conditions by venting a small amount of steam. Releasing the steam prevents the device from overheating. Likewise, releasing the vapors also prevents the buildup of compounds in the condenser space that may interfere with the functioning of the device.

[0165] Typically, the control valves may be of the same type. In an exemplary embodiment, the control device is a solenoid valve series 4BKR, model number 9-4BKR-55723-1-002, manufactured by Spartan Scientific, Boardman, Ohio 44513. In an alternative embodiment, the control device may be, but is not limited to, a proportional valve. The control valve is electronically operated using a 0-5 volt electrical input.

[0166] The device may also include a backpressure regulator, such as that described in U.S. Patent Application Publication No. 2005 / 0194048A1, entitled "Backpressure Regulator," published September 8, 2005, the contents of which are incorporated herein by reference.

[0167] The water vapor distillation apparatus may include a voltage regulator. Typically, the apparatus may receive single-phase power provided from a conventional wall outlet. However, in other countries, the voltage may differ. To accommodate this voltage difference, a voltage regulator may be included in the apparatus to ensure that the correct type of voltage is supplied to the electrical components of the apparatus.

[0168] Additionally, a battery may be included in the system to provide electrical energy to the device. If electrical energy is supplied from a battery, the device preferably includes an electrical inverter to change the incoming electricity from direct current to alternating current. In other embodiments, the device may receive electrical energy from Stirling and internal combustion engines. These embodiments may also require an electrical inverter. In other embodiments, the device may include a boost loop to increase the amount of voltage supplied to the device to power the electrical components. (How to distill water) Also disclosed herein is a method of steam distillation that includes filtering source water, heating the source water using a heat exchanger, converting the source water to low-pressure steam, removing water from the feed steam to produce dry low-pressure steam, compressing the dry low-pressure steam to high-pressure steam, and condensing the high-pressure steam into product water.

[0169] Referring now to Figures 22-22A, source water is contaminated water that is converted to steam and later condenses into clean, purified water, called product water. Figure 22 illustrates the fluid path of the source water within the previously disclosed apparatus. The source water enters the apparatus through an inlet pipe connected to a heat exchanger, as shown in Figure 22A. Typically, a pump may be installed to cause the source water to flow through the inlet pipe and into the heat exchanger. There may be a strainer 2202 installed within the inlet pipe between where the feedstock enters the pipe and the connection with the heat exchanger (see Figure 22A). In other embodiments, a regulator 2204 may be placed within the inlet pipe to regulate the flow of source water into the apparatus. Similarly, in one embodiment, a valve 2206 may be placed within the inlet pipe to isolate the apparatus from the water source.

[0170] Still referring to FIGS. 22-22A , during operation, source water passes through strainer 2202 to remove large particulates. These large particulates may adversely affect the operation of the device by clogging the inlet and discharge valves or the inner tubes of the heat exchanger. Particulates may also accumulate on the evaporator / condenser tubes, reducing the efficiency of the device. In the exemplary embodiment, strainer 2202 is located before the control valve. In other embodiments, the strainer may be located before the inlet pump (not shown). In the exemplary embodiment, strainer 2202 has a 50μ user cleaner unit. In alternative embodiments, the device may not include strainer 2202. After the source water passes through strainer 2202, the water enters heat exchanger 2208.

[0171] Referring now to FIG. 22B , upon entering the heat exchanger 2208, the source water may fill the outer tubes of the heat exchanger 2208. In an exemplary embodiment, the heat exchanger is a counterflow tube-in-tube heat exchanger. The source water enters the heat exchanger at approximately ambient temperature. Conversely, the product and blowdown waters enter the heat exchanger having temperatures higher than ambient. The source water enters the heat exchanger at one end, and the product and blowdown waters enter the heat exchanger at the opposite end. As the source water flows through the heat exchanger, the high thermal energy of the product and blowdown waters is transferred outward from the inner tubes of the heat exchanger to the source water. This increase in the temperature of the source water allows the water to more efficiently turn into steam in the evaporator / condenser.

[0172] Referring now to FIGS. 22C-D, once the source water passes through the counterflow tube-in-tube heat exchanger, the water exits the heat exchanger and enters the regenerative blower motor cooling loop. During operation, the regenerative blower motor 2210 generates thermal energy. This thermal energy must be removed from the blower motor 2210 for the blower to operate properly. As the source water passes through the blower motor cooling loop, the thermal energy generated by the blower motor is transferred to the source water. The heat transfer increases the temperature of the source water, allowing the blower motor to maintain a lower operating temperature. A higher source water temperature increases the efficiency of the device because less energy is required to cause the source water to change phase to steam. The source water exits the regenerative blower motor cooling loop and enters the evaporator / condenser through a sump 2212, shown in FIG. 22E.

[0173] Referring now to Figures 23-23A, the device also contains a high concentration of source water, referred to as blowdown water. This water removes particulates from the device to prevent scaling on the evaporator / condenser tubes. This fluid may contain non-volatile contaminants that were present in the source water. These contaminants may include, but are not limited to, scale from pollutants, heavy metals, or organic compounds. Specifically, these contaminants may include, but are not limited to, calcium carbonate and magnesium carbonate. Additionally, the blowdown water transfers thermal energy to the source water as it passes through the heat exchanger. Figure 23 illustrates the blowdown water fluid path within the previously disclosed device. The blowdown water is collected in the steam chamber 2302, as shown in Figure 23A. As low-pressure steam passes through the steam chamber 2302, water droplets separate from the steam. These water droplets accumulate at the bottom of the steam chamber 2302 and add to the existing blowdown water. As the blowdown water level increases, water exits the steam chamber 2302 through a port. It is through this port that blowdown water exits the steam chamber 2302 and enters the level sensor housing 2304 shown in Figure 23A.

[0174] 23B-C, blowdown water enters the level sensor housing 2304 and fills the settling tank 2306. As the blowdown water passes through the settling tank 2306, particulates in the water settle to the bottom of the tank, thus separating the water from the particulates. Separating the particulates from the water prevents the particulates from entering the heat exchanger. The heat exchanger may be adversely affected by the presence of particulates in the water. Particulates may collect on the inner tubes of the heat exchanger, causing the heat exchanger to be less efficient. Particulates may reduce the blowdown flow through the inner tubes, reducing the amount of heat energy that can be transferred to the source water. In some cases, a group of particulates may create a blockage in the inner tube, obstructing the flow of blowdown water through the heat exchanger. As the blowdown water fills the settling tank 2306, the water may also fill the blowdown level sensor reservoir 2308, shown in FIG. 23C.

[0175] Referring now to Figures 23D-G, as the blowdown water exits the level sensor housing 2304, it may pass through a strainer 2310 before entering the heat exchanger 2312 shown in Figure 23E. The strainer 2310 removes any particulates remaining in the blowdown water after flowing through the settling tank 2306 of the level sensor housing 2304. Removing particulates from the blowdown water reduces particulate buildup in the heat exchangers and valves in the system. The blowdown water enters the heat exchanger 2312 and fills one of the inner tubes, as shown in Figure 23E. The water fills the heat exchanger 2312, as illustrated in Figure 23F. As the blowdown water passes through the heat exchanger, thermal energy is transferred from the higher temperature blowdown water to the lower temperature source water through the tubes containing the blowdown water. The blowdown water exits the heat exchanger, as illustrated in Figure 23G. After exiting the heat exchanger, the discharge fluid passes through a mixing can 2314 to prevent vapors being discharged from the device from potentially harming individuals or nearby objects. Vapors may be periodically vented from the condenser space to maintain device energy balance. Similarly, gaseous vapors (e.g., volatile organic compounds, air) must be purged from the condenser space to maintain proper operation of the device. Both vapors and gaseous vapors are discharged into the mixing can 2314 with low-temperature discharge water. Condensing the vapors by mixing them into the discharge water allows them to be safely discharged. In other embodiments, there may be valves located in the tubing connecting the heat exchanger 2312 and the mixing can 2314 to isolate the mixing can from the device or to adjust the flow rate of the discharge water exiting the device.

[0176] Referring now to Figures 24-24A, product water is formed when high-pressure steam condenses when it contacts the outer surfaces of the tubes in the evaporator / condenser. Figure 24 illustrates the fluid path of product water within the previously disclosed apparatus. Product water is generated in the evaporator / condenser 2402, as shown in Figure 24A. As high-pressure steam condenses against the outer surfaces of the evaporator / condenser tubes, it forms water droplets. These water droplets accumulate at the bottom of the evaporator / condenser 2402, creating product water. As the product water level increases, water exits the evaporator / condenser 2402 through a port and enters the level sensor housing 2404, shown in Figure 24A.

[0177] 24B-24E, product water may enter the level sensor housing 2404 through a port connected to the product level sensor reservoir 2406 shown in FIG. 24B. This reservoir collects the incoming product water and measures the amount of water produced by the apparatus. The water exits the product level sensor reservoir 2406 and enters the heat exchanger 2408 shown in FIG. 24C. While passing through the heat exchanger 2408, the hot product water transfers thermal energy to the cold source water through the inner tube of the heat exchanger 2408. FIG. 24D illustrates the product water passing through the heat exchanger 2408. After passing through the heat exchanger 2408, the product water exits the apparatus as shown in FIG. 24E. In an exemplary embodiment, the apparatus may include a product diversion valve 2410 and a product valve 2412. The product valve 2412 allows an operator to regulate the flow of product water exiting the apparatus. Typically, once the reservoir is 50 percent full, the product valve 2412 is cycled so that the amount of water entering the reservoir equals the amount leaving the reservoir. During initial start-up of the system, for the first few minutes of production, the product water being produced is rejected as waste by opening the product diversion valve 2410. Once the product is determined to be of sufficient quality, the product diversion valve 2410 closes and the product valve 2412 begins operation.

[0178] 24F-24H, as product water fills the product level sensor reservoir 2406, the water may also enter the bearing supply water reservoir 2410. The bearing supply water reservoir 2410 collects incoming product water for lubricating the bearings in the regenerative blower 2412. The product water may exit the bearing supply water tank 2410 and enter the pump 2414, as shown in FIG. 24G. The pump 2414 moves the product water to the regenerative blower. After exiting the pump 2414, the product water enters the regenerative blower 2412, as shown in FIG. 24H.

[0179] 24H-24I, as it enters the blower 2412, the product water provides lubrication between the bearings and the blower shaft. After exiting the regenerative blower 2412, the product water may re-enter the level sensor housing 2404 through the bearing feed water reservoir 2410 (see FIG. 24I).

[0180] Referring now to FIGS. 25-25C, ventilation paths may be provided to aid in the flow of water throughout the apparatus. These paths aid in the flow of water through the apparatus by removing air or steam from the apparatus. The ventilation paths are shown in FIG. 25. FIG. 25A illustrates the ventilation path from the discharge level sensor reservoir 2502 to the steam chamber 2504 of the evaporator / condenser 2508. This path allows air within the reservoir to exit, allowing more discharge water to enter the reservoir. Similarly, FIG. 25B illustrates the ventilation path from the product level sensor reservoir 2506 to the evaporator / condenser 2508. This path allows air within the reservoir to exit, allowing product water to enter the reservoir. Finally, FIG. 25C illustrates the ventilation path from the condenser area of ​​the evaporator / condenser 2508, allowing air within the apparatus to exit the apparatus through the mixing can 1510 and into the ambient air. Additionally, the vent helps maintain the equilibrium of the device by venting small amounts of vapor from the device.

[0181] Referring now to FIG. 26, during operation, source water enters the sump 2602 of the evaporator / condenser 2608 in the manner described in FIGS. 22-22E. When the source water initially enters the sump 2602, additional thermal energy may be transferred to the water using a heating element. Typically, the heating element may be used during initial startup of the water vapor distillation apparatus. Otherwise, the heater is typically not used. As the amount of source water in the sump increases, water flows out of the sump and into the evaporator / condenser tubes 2604 through ports on the inside of a plate 2606, illustrated in FIG. 26, positioned between the sump 2602 and the evaporator / condenser 2608. During initial startup of the apparatus, the evaporator portion of the evaporator / condenser 2608 is filled with source water until a sufficient amount of water is present in the discharge level sensor reservoir. After initial startup, the tubes 2604 remain full of source water.

[0182] Referring now to Figures 26A-26E, once inside the tubes 2604, the source water is heated by conduction of thermal energy through the tube walls from the high-pressure steam present outside the tubes 2604. Figure 26A illustrates wet low-pressure steam flowing through the tubes 2604 of the evaporator / condenser 2608. The wet low-pressure steam travels through the tubes 2604 of the evaporator / condenser 2608 and enters the steam chest 2610, illustrated in Figure 26B. As the steam flows through the interior of the steam chest 2610, water droplets within the steam separate from the steam. These water droplets collect at the base of the steam chest 2610 and are added to the blowdown water already present at the base (see Figures 26C-D). The blowdown water exits the device in the manner described in Figures 23-23G. Dry low-pressure steam exits the steam chest 2610 and enters the regenerative blower 2612, as illustrated in Figures 26E-F.

[0183] 26F-H, once in the regenerative blower 2612, the dry, low-pressure steam is compressed to produce dry, high-pressure steam. After the dry steam is compressed, the high-pressure steam exits the regenerative blower 2612 and enters the steam pipe 2614 of the steam chest 2610. See Figures 26G-H, which illustrate the steam exiting the blower 2612 and entering the steam pipe 2614 of the steam chest 2610.

[0184] Referring now to FIGS. 26H-J, a steam pipe 2614 is fluidly connected to the interior cavity of the evaporator / condenser 2608. The steam pipe 2614 provides an independent path for steam to enter the condenser side of the evaporator / condenser 2608 from the blower 2612. The high-pressure steam is separated to maintain the steam pressure and ensure that the steam is free of contaminants. The dry high-pressure steam exits the steam pipe 2614 of the steam chest 2610 and enters the interior cavity of the evaporator / condenser 2608. See FIG. 261, which shows the interior cavity of the evaporator / condenser 2608 containing the high-pressure steam. As the high-pressure steam contacts the outer surfaces of the tubes 2604 of the evaporator / condenser 2608, the steam transfers thermal energy to the tubes 2604. This energy is conducted through the tube walls to the source water located within the tubes 2604. As energy is transferred from the steam to the tube walls, the steam condenses from the vapor to a fluid. This fluid is known as product water. As water droplets form on the outside of the tube walls, they flow down to the base of the evaporator / condenser 2608. See FIG. 26J, which shows the formation of product water within the interior cavity of the evaporator / condenser 2608. When the amount of product water in the cavity is sufficient, the product water may flow out of the evaporator / condenser, as illustrated in FIGS. 24-24I.

[0185] Referring now to FIG. 27, there are several factors that can affect the performance of the described apparatus. One of these factors is the pressure differential across the regenerative blower. FIG. 27 is a graph illustrating the relationship between the amount of energy required to produce one liter of product and the change in pressure across the regenerative blower. Ideally, one would like to operate the blower to produce the maximum amount of product water using the minimum amount of electricity. From this graph, it can be seen that operating the blower at a pressure differential between 1.5 psi and 2 psi produces one liter of product water using the minimum amount of energy. Operating the blower at pressures above or below this range increases the amount of energy required to produce one liter of water.

[0186] Referring now to FIG. 28, another factor that may affect the performance of the device is the number of heat transfer tubes installed within the internal cavity of the evaporator / condenser assembly. FIG. 28 illustrates the relationship between the number of heat transfer tubes and the product water production flow rate for a given change in pressure across the regenerative blower. From this graph, it can be seen that having a greater number of heat transfer tubes increases product water production. In this graph, the configuration that produces the greatest amount of product water per hour is the assembly with 85 tubes. The configuration that produces the least amount of water is the assembly with only 43 tubes for pressures below 2 psi.

[0187] Referring now to Figure 29, this figure illustrates the amount of product water produced by different heat transfer tube configurations. In this graph, the configuration with 102 heat transfer tubes produced the highest amount of product water. In contrast, the configuration with the shorter tube length and only 48 tubes produced the least amount of product water.

[0188] Referring now to Figure 30, despite having fewer tubes than the other configurations, the 48 heat transfer tube configuration produces more water per surface area. Figure 30 illustrates the relationship between the amount of product produced and the amount of heat transfer surface area. The graph shows that the 48 heat transfer tube configuration with a 15-inch tube length is the most efficient design. The least efficient configuration is the 102 heat transfer tube design. Therefore, although having a large number of tubes in the evaporator / condenser may produce more water, a design with a fewer number of tubes may provide the most efficient use of resources.

[0189] Referring now to Figure 31, this graph shows the difference in performance between two 48 heat transfer tube designs. In this graph, the difference between the designs is the tube length. At various pressure changes across the regenerative blower, this graph contrasts the amount of energy used and water production flow rate for the two configurations. The configuration with 20 inch long tubes produces slightly more product while consuming slightly less energy at a uniform pressure differential across the regenerative blower. (Control method) The pressure differential across the compressor directly determines the amount of product water the unit can produce. The pressure differential across the compressor can be adjusted to ensure a specific amount of product water output from the unit. Increasing the compressor speed typically results in an increase in the pressure differential across both the evaporator / condenser. Increasing the pressure differential increases the rate at which source water is evaporated into clean product water.

[0190] One of the limiting factors in controlling the steam distillation apparatus 100 is the amount of blowdown water required to operate the machine. Without sufficient blowdown water, particulates that are separated from the source water remain in the apparatus. This buildup of particulates adversely affects the operation and efficiency of the apparatus.

[0191] To ensure that particulates are removed from the device, there must be a sufficient amount of blowdown water to carry the particulates out of the device. To determine how much blowdown water is needed to operate the device in a particular environment, the amount of water entering the device (source water) must be known. If the source water has a high concentration of particulates, more blowdown water is needed to absorb and remove the particulates from the device. Conversely, if the source water has a low concentration of particulates, less blowdown water is needed.

[0192] A number of different control methods may be implemented to control and monitor the amount of product and blowdown water produced by the apparatus. These methods may include, but are not limited to, measuring the product and blowdown water levels in reservoirs located within the apparatus, measuring the flow rates of the product and blowdown water produced by the apparatus, measuring the amount of influent source water, and measuring the output amount of product water.

[0193] The level sensor assembly of the exemplary embodiment may measure both the water level and the water flow rate. The water level may be measured by the movement of the level sensor assembly. As the water fills the reservoir, the water causes a change in the position of the level sensor assembly.

[0194] By knowing the change in position of the level sensor assembly, the area of ​​the reservoir, and the time associated with the change in water level, the water flow rate may be determined. Using a float sensor to determine flow is advantageous because there is no pressure drop due to the use of a float sensor. The flow rate may indicate the performance of the equipment and whether that performance is consistent with normal operation of the equipment. This information allows the operator to determine whether the equipment is functioning properly. For example, if the operator determines that the flow rate is below normal operating conditions, the operator may check the strainer in the inlet piping for impurities or the evaporator / condenser tubes for scale. Similarly, the operator may use the flow rate to make adjustments to the equipment. These adjustments may include changing the amount of blowdown and product water produced. While the flow rate may indicate equipment performance, this measurement is not necessary.

[0195] The quality of either the influent source water or the effluent product water may be used to control the operation of the steam distillation apparatus. The control method determines the operation of the machine based on the water quality. In one embodiment, the conductivity of the product water is monitored. If the conductivity exceeds a specified limit, a sensor sends a signal to shut down the apparatus. In some embodiments, the sensor may be, but is not limited to, a conductivity sensor. Alternative embodiments may include monitoring the conductivity of the blowdown water. If the conductivity of the blowdown water exceeds a specified limit, the sensor sends a signal to increase the amount of source water entering the apparatus. The increase in source water reduces the conductivity of the blowdown water. In another embodiment, the conductivity of the source water may be monitored. If the conductivity exceeds a specified limit, the sensor sends a signal to adjust the flow rate of the source water. Higher source water conductivity may result in higher flow rates of the source water and blowdown water.

[0196] In an alternative embodiment, the device may include a control scheme in which the device has a steady mode. During this mode, the device reduces the amount of power consumed. In other embodiments, during this mode, the heating element may continue to maintain a particular temperature or temperature range of the source water in the sump. Maintaining the temperature of the source water in the sump reduces the amount of time it takes for the machine to begin producing more product water. Additionally, during this mode, the regenerative blower is not functioning and the inlet and outlet valves are closed.

[0197] Examples of tests that may be performed on source water samples to analyze the quality of the source water include, but are not limited to, bacterial tests, mineral tests, and chemical tests. Bacterial tests indicate the amount of bacteria that may be present in the sample. The most common type of bacterial test is total coliform.

[0198] Mineral test results may indicate the amount of mineral impurities in the water. Large amounts of minerals and other impurities may pose health hazards and affect the appearance and usability of the water.

[0199] Another type of water testing that may be performed is chemical testing. Many man-made chemicals contaminate water supplies and can pose health hazards to water consumers. Unless a specific chemical or type of substance is suspected to be in the water, this type of testing may not be performed routinely because it is expensive for unspecific chemical contaminants. However, if a specific chemical is suspected to be present in the source water, testing may be performed. Some specific water quality testing examples are described below.

[0200] pH - Measures the relative acidity of water. A pH level of 7.0 is considered neutral. Pure water has a pH of 7.0. Water with a pH level below 7.0 is considered acidic. The lower the pH, the more acidic the water. Water with a pH greater than 7.0 is considered basic or alkaline. The higher the pH, the greater its alkalinity. In the United States, the pH of natural water is typically between 6.5 and 8.5. Freshwater sources with a pH below 5 or above 9.5 may not be able to provide nutrients to plant or animal species. pH may be determined using any method known in the art for testing.

[0201] The pH is preferably measured immediately at the source water testing station, as changes in temperature affect pH values. Preferably, the water sample is taken below the surface, away from the "bank" if using a lake, stream, river, puddle, etc.

[0202] Nitrate - Nitrogen is an element required by all living plants and animals to build proteins. In aquatic ecosystems, nitrogen exists in many forms. It may combine with oxygen to form a compound called nitrate. Nitrates can come from fertilizers, sewage, and industrial waste. They can cause eutrophication of lakes and ponds. Eutrophication occurs when nutrients (such as nitrates and phosphates) are added to a body of water. These nutrients usually come from agricultural fields, sewage, detergents, animal waste, and runoff from leaking septic systems. The presence of nitrate may be determined using any known method in the art for testing.

[0203] Turbidity - Turbidity refers to how clear or murky the water is. Clear water has low turbidity levels, while cloudy or muddy water has high turbidity levels. High levels of turbidity can be caused by suspended particles such as soil, sediment, sewage, and plankton. Soil can enter the water through erosion or runoff from nearby land. Sediment can be stirred up by excessive activity in the water, for example, by fish or humans. Sewage is the result of waste runoff, and high levels of plankton can be due to excess nutrients in the water.

[0204] When water has high turbidity, there are many suspended particles in it. These soil particles block sunlight and prevent aquatic plants from obtaining the sunlight they need for photosynthesis. Plants produce less oxygen, thereby reducing DO levels. Plants die more easily and are decomposed by bacteria in the water, which further reduces DO levels. Turbidity can be determined using any known method in the art for testing.

[0205] The presence of coliform bacteria in a water supply is a sign that the water supply may be contaminated with sewage or other septic waste. Coliform bacteria are usually found in large numbers on the surface film of the water or in bottom sediments.

[0206] Fecal coliform bacteria, found in the lower intestine of humans or other warm-blooded animals, is a type of coliform bacteria. The presence of fecal coliform bacteria in a water supply is a clear sign that sewage has contaminated the water. Testing may be done specifically for fecal coliform bacteria or for total coliform bacteria, including all E. coli strains, and may indicate fecal contamination. The presence of E. coli may be determined using any method known in the art for testing.

[0207] During operation, the water machine may perform conductivity tests on source water and / or product water to determine the quality of the water entering and exiting the system. This test may be accomplished using conductivity sensors installed in the inlet and outlet piping of the system. Water with a high conductivity indicates that the water has a greater amount of impurities. Conversely, water with a lower amount of conductivity indicates that the water has a lower level of impurities. This type of test is comprehensive and provides only a general indication of the purity / quality of the water being analyzed.

[0208] Other types of tests may be performed to analyze specific levels of water impurities / characteristics, including, but not limited to, pH, hardness, chloride, color, turbidity, sulfate, nitrite, nitrate, and E. coli. Typically, to analyze water entering or exiting the machine, the operator may first obtain a water sample. After obtaining the desired sample, the water may be tested using a water testing kit available from Hach Company (Loveland, Colorado 80539-0389). Other methods of testing water purity may include sending the water to a laboratory for analysis. (a system for distilling water) Disclosed herein is where the previously disclosed apparatus for distilling water may be implemented in a distribution system, as described in U.S. Patent Application Publication No. 2007 / 0112530A1, entitled "Systems and Methods for Distributed Utilities," published May 17, 2007, the contents of which are incorporated herein by reference. Additionally, a monitoring / communication system may also be included within the distribution system, as described in U.S. Patent Application Publication No. 2007 / 0112530A1, entitled "Systems and Methods for Distributed Utilities," published May 17, 2007, the contents of which are incorporated herein by reference. Alternative Embodiments Although exemplary embodiments of a distiller / steam distillation apparatus have been described, alternative embodiments of the distiller are contemplated, including alternative embodiments of specific elements of the distiller (i.e., heat exchangers, evaporators / condensers, compressors, etc.). Thus, in some alternative embodiments, one or more of the elements are replaced with elements of alternative embodiments described herein. In some embodiments, the entire distiller is replaced with an alternative embodiment; for example, a system as described in one embodiment utilizes an exemplary embodiment as a distiller, while in other embodiments, the system utilizes an alternative embodiment.

[0209] Referring to Figures 32-32C, an alternative embodiment of a water vapor distillation apparatus having a liquid ring pump 3200 is disclosed. The ring pump may include a fully rotating housing, which provides the greatest reduction in friction losses while still maintaining the simplicity and cost-effectiveness of the design shown in Figures 32 through 32C. As shown in Figure 32, a stator 3202 is stationary relative to a rotor 3204 and includes an inlet 3206 and an outlet 3208. Vapor is drawn in at pressure P1 and enters a rotor chamber 3210. The rotor 3204 is offset from a central axis Z, on which the rotating housing and the center of the liquid ring pump reside. As the rotor 3204 orbits around a central axis 3212 with a rotor bearing 3214, the effective volume of the chamber 3210 decreases. This causes the vapor to be compressed to pressure P2 as it is conveyed along a rotational path into the outlet 3208 and sent to the evaporator / condenser 104 of Figure 1. Preferably, a rotating housing (not shown) rotates with the liquid ring in the liquid ring pump to reduce energy losses due to friction.

[0210] Referring to Figures 32A-B, the stator 3202 has support structures 3216 in the input and output regions. Below the support structure 3216 in the top view of the stator 3202 shown in Figures 32A-B, the individual blades 3218 of the rotor 3204 can be seen, as well as the concentric arrangement of the rotor 3204 around the central axis. This particular embodiment of a liquid ring pump is axially fed and axially discharged and may have a vertical, horizontal, or other orientation during operation. Figure 32C shows yet another view of this embodiment.

[0211] The liquid ring pump 3200 is generally designed to operate within a very narrow range of input and output pressures, such that the device operates in the range of 5 to 15 psig. Device pressure may be regulated using a check valve that releases vapor from chamber 3210 in FIGS. 32-32C. Improved device performance is preferably achieved by positioning the exhaust port outlet 3208 at a specific angle of rotation about the rotor axis, the specific angle corresponding to the pressure increase desired for the distillation operation. One embodiment of a specific port opening angle for regulating device pressure is shown in FIG. 32A. The outlet 3208 is positioned at approximately 90 degrees of rotation around the rotor access, allowing vapor from chamber 3210 to vent. Positioning the outlet 3208 at a high angle of rotation about the stator axis increases device pressure and reduces pump throughput, while positioning the outlet 3208 at a lower angle about the stator axis results in lower device pressure and increased pump throughput. Selecting the location of outlet 3208 to optimize system pressure may result in improved pump efficiency. Additionally, locating outlet 3208 to maintain system pressure may minimize system complexity by eliminating a check valve at the exhaust port to chamber 3210, thereby providing a simpler, more cost-effective compressor.

[0212] Referring now to FIG. 32D, during operation, it may be desirable to measure the depth of the liquid ring in the compressor to optimize performance. In the embodiment disclosed herein, the liquid ring pump housing 3232 rotates with the liquid ring in the pump, and the temperature of the fluid is typically about 110° C. Methods for measuring the depth of the ring include any one of the conventional methods, such as using ultrasonic, radar, float, fluid conductivity, and optical sensors. Due to the complexity of the rotating housing, the use of a capacitive sensor is the preferred embodiment for this measurement; as the depth of the fluid in the capacitor changes, so does the capacitance of the capacitor.

[0213] 32D , a disc-shaped capacitor sensor plate 3234 is attached to the bottom of the rotating housing 3232, equidistant from the bottom surface 3232A of the rotating housing 3232 and the bottom surface 3204A of the rotor 3204. A capacitor is thus defined by the housing 3232, the rotor 3204, and the capacitor sensor 3234. Leads 3240 connect the capacitor from the capacitor sensor 3234 through passages 3236A in the rotating housing shaft 3236 to a secondary 3242 (not shown), preferably of ferrite core, of a transformer. In one embodiment, the secondary 3242 rotates at the same speed as the capacitor plate and is in inductive communication with the primary of the ferrite core transformer. The primary winding 3238 is stationary, and signals traveling to and from the level-measuring capacitor are transmitted through the transformer, thus allowing depth information to be transmitted from a rotating position to a stationary position. The capacitance is measured by determining the LC resonance of a capacitor (C) with the inductance (L) of the transformer secondary. In an exemplary embodiment, an LC oscillator circuit is constructed and the oscillation frequency is used as a measure of the capacitance.

[0214] Referring to FIG. 32E, this figure illustrates an alternative design of a pump 3200 to prevent contaminating fluid droplets from being entrained and carried along with the steam to the evaporator / condenser 104 of FIG. 1. In such an embodiment, the liquid ring pump 3200 is within the headspace of the evaporator / condenser 104, and spray is eliminated as the rotating housing 3232 rotates; the rotation creates a cyclone effect, and centrifugal force throws the spray and droplets, forcing them to collide with the still housing and fall into the water in the sump. There may also be fins 3244 extending from the outside of the rotating housing 3232 to enhance circulation and rotation of the steam in the annular space between the rotating housing 3232 and the stationary housing 3228. A flow outlet 3242 is provided in the flow passage to the evaporator / condenser 104.

[0215] 32F-G, an alternative embodiment of a liquid ring pump 3200 may include a ring pump 3252 with an outer rotating housing 3254 surrounding a single two-channel stator / body 3256 and rotor 3258, where the sealing surface between the rotating housing 3254 and the stationary stator / body 3256 is a cylinder. The two-channel stator / body 3256 remains stationary with respect to the chamber 3260 of the pump 3252, as well as the rotor 3258 and rotating housing 3254, and includes an inlet 3262 and an outlet 3264. Steam is drawn in at P1 and passes through the inlet 3266. As the rotor rotates around the stationary stator 3256, when the inlet 3266 aligns with the inlet hole 3268 in the rotor 3258, steam passes through the inlet hole 3268 into the rotor chamber 3270. The rotor 3258 is offset from the central axis Z so that as the rotor 3258 spins, the effective volume of the rotor chamber 3270 decreases. Thus, steam is compressed to pressure P2 as it is conveyed along a rotational path to the outlet hole 3272 of the rotor 3258. As the rotor 3258 spins, the outlet hole 2 aligns with the outlet 3274 of the stationary outlet 3264, and steam at pressure P2 passes through the outlet 3274 into the outlet 3264 where it is sent to the evaporator / condenser. In such an embodiment, the rotating housing 3254 rotates with the water 3276 present in the chamber 3260, thereby reducing frictional energy losses due to windage. There may also be small holes 3278 present in the housing 3254 to allow water 3276 to exit and / or enter the chamber 3260, thereby controlling the fluid level in the pump. Additionally, rotor 3258 has a plurality of vanes 3280 that are readily visible when rotor 3258 is viewed from above, as in Figure 32G. The individual rotor chambers 3270, as well as the individual intake holes 3268 and exit holes 3272 for each rotor chamber 3270, are also readily apparent from this view.

[0216] 32H, in an alternative embodiment of a liquid ring pump, the interface between the rotating housing 3254 and the stator 3256 is conical rather than cylindrical. In this embodiment, the rotor drive shaft 3282 has an end 3286 disposed on a bearing 3284 that allows the rotating rotor housing 3254 to rotate with the rotor 3258. The inlets 3262 and outlets 3264, along with the corresponding inlets 3266 and outlets 3274, remain stationary relative to the rotor 3258 and rotor housing 3254.

[0217] 32F, H, and I, other further embodiments may include a conical or axial seal 3282 present between the stationary portions 3264 and 3262 and the rotor 3258. In the conical embodiment, seen most clearly in FIG. 32I, the seal 3282 thereby separates the intake 3266 from the outlet 3274 of the rotor 3258 to prevent leakage. In contrast to the axially fed and axially discharged liquid ring pump embodiment discussed with respect to FIGS. 32-32C (see above), the liquid ring pump shown in FIGS. 32E-I and 32F is axially fed and radially discharged.

[0218] In an alternative embodiment, the steam distillation apparatus may include a backpressure regulator. The backpressure regulator may assist in maintaining safe and optimal operation of a process conducted under pressure. During operation, the steam distillation apparatus may include a backpressure regulator to purify brackish or seawater into potable water; excessive system pressure generated from volatile components during startup or from a compressor operating off-spec may be dangerous to operators if such pressure is not safely relieved. Similarly, volatile components present in the feed stream during startup may present contaminants that interfere with proper operation of the apparatus. The backpressure regulator may act to relieve excess pressure and return the operating apparatus to the desired operating pressure.

[0219] The aforementioned steam distillation apparatus embodiments generally operate above atmospheric pressure, typically about 10 psig. Such apparatus advantageously provide higher vapor density at higher pressures, thereby allowing more vapor to be pumped through the volumetric pump than at lower pressures. The resulting higher throughput provides improved overall system efficiency. Furthermore, higher throughput and higher system pressure reduce the power required for the compressor and eliminate the need for two additional pumps: one to pump the concentrated product and one to pump the bleed stream. Overall construction is simplified because many geometries tolerate internal pressure better than external pressure. Importantly, operating at superatmospheric pressure reduces the impact of minor leaks on overall efficiency and performance. Noncondensable gases, such as air, inhibit the condensation process and expand below atmospheric pressure, where minor leaks act as air intakes, something that does not occur in systems operating at superatmospheric pressure.

[0220] 33 and 33A, which show diagrams of a backpressure regulator that may be incorporated into the water vapor distillation apparatus 100 when operating the apparatus above atmospheric pressure. The backpressure regulator 3300 has a vessel 3302 containing an opening 3304. One side of the opening is connected to a pressurized conduit of the apparatus (e.g., the outlet of a compressor in a vapor compression distillation apparatus), which may be exposed to constantly fluctuating high pressures. The other side of the opening terminates in a port 3306. The port 3306 is covered by a spherical movable stop 3308. The stop 3308 is held by a retainer 3312 to an arm 3310 at a fixed distance from a pivot pin 3314. The arm 3310 is hinged via the pivot pin 3314 to a point in fixed relationship to the opening port 3306. The arm 3310 includes a counter mass 3316 suspended from the arm that is movable along an axis 3318 so that the distance between the counter mass 3316 and the pivot pin 3314 may be varied. In the embodiment shown in Figure 33, the axial direction of the opening 3304 is perpendicular to the direction 3320 of the gravity vector. The backpressure regulator may also include a housing that prevents foreign objects from entering the regulator and disrupting the function of the internal components.

[0221] 33 and 33A , in operation, when the pressure in the pressurized conduit is below a given set point, the arm 3310 maintains a horizontal position relative to the direction of gravity 3320. This arm position, in this embodiment, is known as the closed position and corresponds to a stop 3308 covering the port 3306. When the pressure in the conduit exceeds the set point, a force acts on the stop 3308, resulting in a torque acting about the pivot pin 3314. The torque acts to rotate the arm 3310 about the pivot pin 3314 in a counterclockwise direction, moving the arm away from its closed position and exposing the port 3306, allowing fluid to escape through the opening 3304. When the pressure in the conduit is below the set point, the force of the gas is no longer sufficient to keep the arm 3310 away from its closed position, and thus the arm 3310 returns to the closed position, with the stop 3308 covering the port 3306.

[0222] Referring again to FIGS. 33 and 33A , the arm 3310 acts as a lever in generating an adjustable moment, multiplying the force applied to the port 3306 through the stop 3308 by the countermass 3316. This force multiplication reduces the weight required to close the opening 3304, as opposed to designs in which only the stop 3308 acts perpendicularly on the top of the opening 3304, as in a pressure cooker. Thus, large port sizes may be covered by a relatively lightweight, large stop to promote rapid venting from the pressurized conduit, and the countermass acts to adjust the desired set point, so less design effort may be expended in selecting a particular port size and stop properties. The addition of a shaft 3318 for adjusting the position of the countermass 3316 allows for variation of the multiplier ratio in this embodiment. As the countermass 3316 is moved closer to the pivot pin 3314, the multiplier ratio is reduced, producing a lower closing force. If the counter mass 3316 is moved further from the pivot pin 3314, the multiplier ratio is increased, thus increasing the closing force. Thus, the position of the counter mass 3316 effectively acts to adjust the set point of the backpressure regulator.

[0223] Adjusting the backpressure regulator set point may be useful when the backpressure regulator is utilized at higher altitudes. When atmospheric pressure is lower, the system operating pressure is correspondingly lower. As a result, the temperature of the distillation system is reduced, which may adversely affect system performance. Similarly, such adjustment allows for identification of the backpressure regulator set point desired by the end user. The use of a countermass to apply a closing force may also reduce the cost of the backpressure regulator and reduce component fatigue. In certain embodiments, the adjustable countermass is designed to allow a range of set points, with a minimum set point substantially below 10 psig and a maximum set point substantially above 17 psig. Thus, various embodiments allow for precise system pressure adjustment, unlike devices that simply act as safety relief valves.

[0224] 33B-C, these figures illustrate an alternative embodiment of a backpressure regulator 3300 having an opening 3326 configured such that the port 3328 is oriented perpendicular to the direction of gravity 3320. Thus, other embodiments may accommodate any opening orientation while maintaining the use of an adjustable countermass.

[0225] The backpressure regulator may be configured to allow a small leak rate below the set point to purge the buildup of volatile gases, which acts to insulate the heat exchange and suppress boil-over in the system. However, the regulator is designed to allow pressure to gradually build up in the pressurized conduit despite this small leak. In one embodiment, release of volatile components from the pressurized conduit below the backpressure regulator set point may also be achieved through a specially designed leak vent while the backpressure regulator arm is in the closed position. The leak vent is configured to allow a certain leak rate from a port or opening while the pressure in the conduit is below the set point. Such a leak vent may be designed by various means known to those skilled in the art. Non-limiting examples include specific positioning of the stop and port to allow a small opening while the arm is in the closed position, designing the port so that a small opening that cannot be covered by the stop is always exposed, specifying a particular rigid and inelastic seal configuration between the stop and port when the arm is in the closed position, and configuring the opening to the port to have a small opening that allows fluid to leak out.

[0226] Referring now to Figures 33D-G, these figures illustrate an alternative embodiment of a backpressure regulator 3300 that allows leakage of volatiles below the set point. In one alternative embodiment, the port 3332 has a notch 3334 as shown in Figure 33D, with an enlarged view of area C of Figure 33D being shown in Figure 33E. Thus, when the stop is in contact with the port 3332, the arm of the backpressure regulator is in a closed position and a leak vent is present at the location of the notch 3334, allowing fluid to leak out. In another alternative embodiment of the backpressure regulator 3300, the opening 3336 has a small opening 3338 as shown in Figure 33F, with an enlarged view of area E of Figure 33F being shown in Figure 33G. The opening 3338 is configured such that when the stop covers the port 3336, a leak vent is created, as fluid may leak through the opening 3338.

[0227] Various features of the backpressure regulator may be altered or modified. For example, stops used with the back pressure regulator may have any shape, size, or mass consistent with the desired operating conditions; such stops need not be spherical as shown in some embodiments discussed herein. Similarly, stops of different weights but similar sizes may be utilized with retainers to modify the regulator's set point. Similarly, countermasses of different sizes, shapes, and masses may be utilized with various embodiments, depending on the preference of the shaft and arm configuration (compare 3316 in FIGS. 33 and 33A with 3330 in FIGS. 33B and 33C). Such countermasses may be attached and oriented relative to the arm by any of a variety of techniques apparent to those skilled in the art. The pivot pin placement need not be as shown in FIGS. 33-33C, but may be located wherever advantageous to provide the mechanical advantage needed to achieve a particular pressure set point.

[0228] 33, other embodiments of the backpressure regulator 3300 may optionally utilize the drain feature previously described. Also, embodiments of the backpressure regulator 3300 may not utilize a countermass force adjustment feature, relying on the particular nature of the stop to provide the set point for the backpressure regulator.

[0229] Other embodiments of the water vapor distillation apparatus may not utilize a vessel but rely on an opening that is inherently part of the system. In such cases, the backpressure regulator arm may be attached directly to a portion of the system such that the arm, stop, and countermass are properly oriented for regulator operation.

[0230] Referring now to FIG. 34 , the vessel 3302 includes a drain 3322. Because the backpressure regulator 3300 may operate within a bounded region 3402 of a larger system 3400, the drain 3322 serves as a pathway to discharge fluid purged from the pressurized conduit 3404 through the opening 3304 into the bounded region 3402. The drain 3322 may connect the bounded region 3402 to another region of the larger system or to the external environment 3406. Additionally, accumulation of gas in the bounded region 3402 may result in condensation of such gas. Gas purged through the opening 3304 may also be mixed with droplets of fluid that may accumulate in the bounded region 3402. Thus, the drain 3322 may also be utilized to clear away any buildup of condensate that accumulates in the bounded region 3402. The condensate may also be discharged from the bounded region using a separate opening 3408.

[0231] 35, in an alternative embodiment, the device may maintain a constant discharge water flow to prevent scale and other buildup in the device, as follows: The water level 3502 in the head chamber 3504 is regulated through a feedback control loop using level sensor L1, valve V1, and feed pump 3506 to maintain the proper water flow through the discharge stream 3508. A three-way feed pump fill valve 3510 is set to pump water into a sump 3512, which raises the water level 3502 in the head chamber 3504. As the fluid level 3502 in the head chamber 3504 rises, the fluid overflows a dam-like barrier 3514 into a discharge control chamber 3516 containing a discharge level sensor L1. If necessary, the discharge valve V1 is controlled to allow water flow from the discharge control chamber 3516 through the heat exchanger 3518 to extract heat, cool the discharge flow 3508, and exit through the volatile mixer 3520 and out the valve V1, allowing cooling of the hot gas and steam 3522 from the evaporator section 3524, then completing the discharge flow to waste 3526.

[0232] 35, the system may also maintain the proper product flow as follows: Product level 3528 increases in condenser chamber 3530 and enters product control chamber 3532, which houses product level sensor L2. Using a feedback control loop with level sensor L2 and valve V2, product flow 3534 is controlled to flow from product control chamber 3532 through heat exchanger 3518, extracting heat and cooling product flow 3534, and then exiting through valve V2 to complete the product flow as product water outlet 3536.

[0233] The system may be configured to maintain the proper liquid ring pump 3538 water level, preferably by using a fluid recovery system to replenish fluid losses. There are several ways in which fluid from the ring pump may be depleted during system operation, including leakage into the lower reservoir 3540, expulsion through the exhaust port 3542, and evaporation. Leakage and rejection losses can be highly dependent on operating parameters such as the rotational speed and throughput of the liquid ring pump 3538. These leakage and rejection losses can require complete replacement of the fluid in the pump several times each hour. Evaporation losses are typically small.

[0234] Referring to FIG. 35 , the fluid level in the ring pump 3538 may be maintained by adding additional source water or product water, or preferably, for improved system efficiency, by recirculating liquid water lost from the liquid ring pump. In one embodiment, the fluid level in the ring pump 3538 is maintained primarily by recirculating fluid accumulated in the lower reservoir 3540. Fluid may accumulate in the lower reservoir 3540 due to leakage from the liquid ring pump 3538 and due to fluid being discharged into the exhaust 3542, captured in the mist eliminator 3544, and pumped into the lower reservoir 3540. Alternatively, fluid discharged into the exhaust 3542 and captured in the mist eliminator 3544 may be returned via the liquid ring pump exhaust port. The fluid accumulated in the lower reservoir may be recirculated by one of several pumping mechanisms. One exemplary method is to use a siphon pump.

[0235] 35, a minimum depth of water is preferably maintained in the lower reservoir for the siphon pump to function properly. In one embodiment, a liquid ring pump control chamber 3546 housing a liquid ring pump level sensor L3 may be used to control the liquid ring pump level and, in turn, the water level in the lower reservoir 3540. The liquid ring pump control chamber 3546 is fluidly connected to the liquid ring pump 3538 and the lower reservoir 3540. The liquid ring pump 3538 is connected to a three-way feed fill valve 3510, which is set to open when the liquid ring pump 3538 needs more water, and is also connected to a liquid ring pump drain valve V3, which opens when water is needed to drain from the liquid ring pump 3538 into the discharge stream 3508.

[0236] 35, if recirculated water from the lower reservoir 3540 is not primarily used to maintain the fluid level in the liquid ring pump 3538, either cold source water or product water may be used. If source water is used, the introduction of cold water (which may be approximately 85°C cooler than the system temperature) to the liquid ring pump 3538 reduces system efficiency, or alternatively, the use of a preheater for such cold source water increases the energy balance of the system. Alternatively, the use of product water does not adversely affect system temperature, but may reduce production levels and therefore lead to system inefficiencies. At start-up, the initial fluid level of the liquid ring pump is preferably supplied from source water.

[0237] Referring now to FIG. 35A , in one embodiment, start-up time may be reduced by using an external connection valve 3550 between the feed 3548 and discharge 3508 fluid lines located adjacent to the cold-side heat exchanger 3518. To determine the fluid level in the evaporator head 3504 during initial fill, the connection valve 3550 is opened, the discharge valve BV is closed, and fluid is pumped into the system through the feed line 3548. Connecting the discharge 3508 and feed 3548 lines results in equal fluid height in the discharge level sensor housing 3516 and the evaporator head 3504, thereby enabling determination of the fluid level in the evaporator head 3504 and allowing the evaporator to be filled to the minimum required level at start-up. Using the required minimum level reduces preheat time and prevents flooding from the evaporator head 3504 through the liquid ring pump 3538 to the condenser 3552 when the liquid ring pump 3538 starts up, as shown in FIG.

[0238] Still referring to FIG. 35A , the concentration of solids in the effluent stream 3508 may be monitored and controlled to prevent materials from precipitating out of solution and thus clogging the system. Also, during startup, a circulation pump 3554 may circulate water through the heat exchanger 3518 to preheat it to the proper temperature for normal operation. A conductivity sensor (not shown) may be used to determine total dissolved solids (TDS) by measuring the electrical conductivity of the fluid. In certain embodiments, the sensor is an inductive sensor, so that no conductive materials are in contact with the fluid flow. For example, during the distillation of seawater, if the TDS content in the effluent stream 3508 rises above a predetermined level, the feed rate of the fluid source is increased. Because distilled water production changes only slightly as a function of fluid feed rate, increasing the feed rate of the fluid source increases the rate of the effluent stream 3508, and the increased effluent flow rate results in a reduced concentration of TDS, thereby maintaining the overall health and productivity of the system.

[0239] Alternative embodiments also include fluid control systems that use a level sensor and a variable flow valve in a feedback configuration. Optimal operation of a still requires that the total fluid inflow closely matches the total fluid outflow. Maintaining the fluid level in the still at a nearly constant level accomplishes this requirement. In certain embodiments, the sensor is a capacitive level sensor, a particularly robust sensor for measuring fluid levels. Capacitive level sensors have no moving parts, are insensitive to fouling, and are simple and inexpensive to manufacture. The opening of the variable flow valve is controlled by the fluid level measured by the capacitive level sensor, thereby regulating the fluid level at the level sensor location. A rising fluid level causes the valve to open further, increasing outflow from the sensor volume. Conversely, a falling fluid level causes the valve to close further, decreasing outflow from the sensor volume.

[0240] The flow rate from the input pump through the variable flow control valve may be determined using in-situ calibration techniques. A level sensor and associated level sensor volume may be used to determine the fill or empty rate of the sensor volume. By appropriately configuring the control valves, the flow rate calibration of each valve, and also the flow rate calibration of the feed pump, may be determined.

[0241] In one embodiment, a valve block (not shown) may be utilized to consolidate all of the control valves of the system into a single component that may be integrated with the fluid flow manifold. A control system may also be incorporated, including sensors for total dissolved solids and discharge flow, as well as float valves or other devices for controlling the height / level of the fluid in the head.

[0242] 35, in addition there is a steam flow line 3554 from the head 3504 to the compressor 3538, a steam outlet 3542 for diverting steam to the evaporator / condenser, a hot product line 3534 from the evaporator / condenser through exchanger 3518 which also allows for collection of hot purified condensed product 3528, and a line (not shown) to divert the hot product to the compressor 3538 to allow constant water level regulation. There may also be a drain line (not shown) for when the system is shut down.

[0243] Referring now to Figures 36-36C, alternative embodiments may also include a fluid distribution manifold 3600. Figure 36 shows one side of the pump side of one particular embodiment of a fluid distribution manifold 3600. An input in the form of a raw feed flows through port 3602, and a blowdown stream (output) flows through port 3604. An additional output in the form of a product stream flows through port 3606, while port / chamber 3608 provides a vent for the volatiles (output), and port 3610 provides a drain (output) for the liquid ring pump. Figure 36A shows the other side of the pump side of the same particular embodiment of a fluid distribution manifold 3600. The port / chamber 3608 for the volatiles output is clearly visible, as is the drain 3610 for the liquid ring pump. In this view of this particular embodiment, the condenser vapor mist eliminator chamber 3612 can be seen, as can the mist collector and drain area 3614.

[0244] Referring specifically to Figure 36B, this figure illustrates a side view of the evaporator / condenser side of the same particular embodiment of fluid distribution manifold 3600. Raw feedstock supply port 3602, as well as discharge and product passage ports 3604 and 3606, are readily visible in this view. Additionally, evaporator vapor passage port 3616 and condenser vapor passage port 3618 are visible.

[0245] Referring specifically to Figure 36B, this figure illustrates the other side of the evaporator / condenser side of the same particular embodiment of the fluid distribution manifold 3600. Again, the discharge through port 3604 can be seen, as can the liquid ring pump drain port 3606, the second condenser vapor mist eliminator 3612, the evaporator vapor mist eliminator 3620, and the mist collector and drain area 3614. Also visible in this view is the sump level control chamber, along with the product level control chamber 3622 and the liquid ring pump supply 3624.

[0246] 36-36C, the fluid distribution manifold 3600 can eliminate most of the piping in a fluid purification system and advantageously incorporates various functionalities, including flow regulation, mist removal, and pressure regulation, into one unit, thereby simplifying manufacturing and reducing overall components. The core plate and manifold may be made of, for example, plastic, metal, or ceramic plate, or any other non-corrosive material capable of withstanding high temperatures and pressures. Methods of manufacturing the core plate and manifold include brazing and overmolding.

[0247] Referring now to Figures 37-37A, these figures illustrate a fitting assembly that allows fluid contact throughout the system in certain embodiments. For example, there may be floating fluid between the heat exchanger 3518 (shown in Figure 35) and the intake / exhaust ports 3220 and 3208 (shown in Figure 32). Figure 37A illustrates a connector 3702 that may be welded to a heat exchanger port (not shown), connecting to a fluid interface 3704 that, in turn, communicates with a fluid distribution manifold. Figure 37A shows a cross-sectional view across line AA (see Figure 37). The connector 3702 has the ability to float to compensate for shifts in alignment that may be caused by temperature or manufacturing variations. Sealing is accomplished by an O-ring 3706. As can be seen from the view shown in FIG. 37, when the O-ring seal 3706 is rotated 90 degrees about its central axis along line AA, the connector 3702 and fluid interface 3704 lock together to form a fluid interface connection.

[0248] 38-38A, which illustrate another embodiment of an evaporator / condenser 3800. As seen in FIG. 38, the evaporator / condenser 3800 is a flat evaporator / condenser containing multiple parallel core layers 3802 and 3804, typically made of a copper-nickel alloy or other thermally conductive material, with ribbed portions 3806 creating channels 3810 and 3812 for directing vapor and condensed fluid flow. The vapor inlet 3814 and product outlet 3816 manifolds (as well as contamination inlet and volatiles outlet manifolds, not shown) may connect to a liquid ring pump / compressor via a fluid interface. Bolts 3818 secure the core evaporator / condenser 3800 to brackets on the outer housing of the liquid ring pump / compressor. In operation, every alternating horizontal (as shown in Figures 38 and 38A) row 3802 and 3804 contains an evaporator channel 3810 and a condenser channel 3812, such that the two functions never overlap on any given layer. Figure 38A, a detail of Figure 38, more clearly shows how the combined evaporator / condenser manifold operates. As shown, columns 3802 do not interact with columns 3804 and are closed off from each other, thereby separating the functions of evaporation and condensation in the horizontal core layer.

[0249] Referring now to Figure 39, this figure illustrates an alternative embodiment of a heat exchanger for use in a water vapor distillation apparatus, which makes full use of available system resources and heat sources. In one particular embodiment, heat from at least one of multiple sources passes through a multi-line heat exchanger 3902, such as that shown in Figure 39, and a series of two-channel heat exchangers, such as 3904, 3906, 3908, and 3910, are plumbed to create a multi-line effect. Note that in the particular multi-line heat exchanger embodiment shown in Figure 39, a cold intake stream 3912 passes through all heat exchanger units 3904, 3906, 3908, and 3910, one heat source, e.g., hot product 3914, flows through heat exchanger units 3904 and 3908, and another heat source, e.g., hot discharge stream 3916, flows through heat exchanger units 3906 and 3910. Thus, multiple heat sources may be used to exchange with the cold intake stream 3912.

[0250] 39A, which illustrates an alternative embodiment of a heat exchanger. In this embodiment, the heat exchanger may be a single multi-channel heat exchanger 3918. In this particular embodiment, a heat source, such as, for example, a cold intake 3912 and a hot output 3914, and a hot output stream 3916, flow simultaneously but in opposite directions through the exchanger 3918, thereby allowing heat exchange from both heat sources 3914 and 3916 with the cold intake 3912 within the single heat exchanger 3912.

[0251] Referring now to FIG. 40, an alternative embodiment may include measuring evaporator and condenser pressures to assess overall system performance and / or provide data to a control system. To avoid the use of expensive sensors required to withstand the high temperatures of the evaporator / condenser 4002, pressure sensors PE and Pc are installed in the fluid lines between the cold side of the heat exchanger 4004 and the corresponding control valves VE and VC. To avoid measuring a pressure lower than the actual system pressure, which occurs when fluid flows against a pressure sensor located in this position, the control valves are momentarily closed to stop the flow. During "no flow" periods, pressure remains constant from the control valves back to the evaporator or condenser, allowing for accurate measurement of system pressure. These short "no flow" periods have no adverse effect on the still's performance.

[0252] 41-41B, which illustrates another embodiment of the present disclosure including a filtration mechanism within the intake to increase the purity of the final product fluid. A multi-unit flip filter 4100 having a pivot joint 4102 joining at least two filter units 4104 and 4106 is disposed within a filter housing 4108, which directs fluid through filter units 4104 and 4106 and facilitates rotation of filter units 4104 and 4106 about central pivot joint 4102. As shown, an outlet flow 4109 passes through flip filter unit 4104, while an intake fluid flow 4110 simultaneously flows from the intake and through flip filter unit 4106 in the course of purification. After a certain interval, a flip filter switch (not shown) rotates flip filter 4100 at flip filter pivot joint 4102 about a central axis indicated by a dotted line so that filter unit 4106, which is fouled with contaminants filtered from the contaminated intake fluid, is backwashed by discharge stream 4109 and filter unit 4104 becomes the filter unit filtering intake fluid stream 4110. In such an embodiment, O-ring gaskets 4112 and 4114 may be utilized as seals between filter units 4104 and 4106 and the fluid flow paths of discharge stream 4109 and intake fluid stream 4110, respectively.

[0253] 41C-D, multi-unit flip filter may be multi-section annular filter 4112. Multi-unit flip filter 4112, having pivot point 4114 around which multiple flip filter units such as 4116 and 4118 pivot, may also be disposed within filter housing 4120, which directs fluid flow through the individual filter units 4116 and 4118 and facilitates rotation of filter 4112 about pivot point 4114. As shown, outlet flow 4109 passes through one flip filter unit 4116, while intake fluid flow 4110 simultaneously flows from the intake and through flip filter unit 4118 during purification. 41 , a flip filter switch (not shown) rotates flip filter 4112 about a central axis indicated by a dotted line at flip filter pivot point 4114 so that filter unit 4118, which is fouled with contaminants filtered from the contaminated intake fluid, is backwashed by discharge stream 4109 and filter unit 4116 becomes the filter unit filtering intake fluid stream 4110. A series of seals, indicated by 4122 and 4124, are utilized between the individual filter units 4116 and 4118 to separate discharge stream 4109 flowing through one filter section from intake fluid stream 4110 flowing through another filter section.

[0254] 41E-41F, other embodiments may include a manual valve 4122 to alter the water flow direction. Such a valve, for example, allows for the use of the discharge stream 4109 to sequentially clean one unit of each flip filter, effectively switching which unit is being filtered and which unit is being backwashed in one operation, thereby backwashing filter unit 4104 or 4106 without having to actually replace the filter 4100 itself. In one particular embodiment, when valve 4122 is in position A, filter unit 4104 is filtering the intake fluid 4110, and filter unit 4106 is backwashed with the discharge stream 4109. Switching valve 4100 to position B causes filter unit 4104 to be backwashed with the discharge stream 4108, and filter unit 4106 to filter the input fluid 4110. (Stirling cycle engine) The various embodiments of the water vapor distillation apparatus described above may, in some embodiments, be powered by a Stirling cycle machine (which may also be referred to as a Stirling engine). In an exemplary embodiment, the Stirling cycle machine is a Stirling engine as described in pending U.S. patent application Ser. No. 12 / 105,854, filed Apr. 18, 2008, having attorney docket number 170, which is incorporated herein by reference in its entirety. However, in other embodiments, the Stirling cycle machine may be any of the Stirling cycle machines described in U.S. Patent Nos. 6,381,958, 6,247,310, 6,536,207, 6,705,081, 7,111,460, and 6,694,731, all of which are incorporated herein by reference in their entirety.

[0255] Stirling cycle machines, including engines and refrigerators, have a long technological tradition, as described in detail in Walker, Stirling Engines, Oxford University Press (1980), which is incorporated herein by reference. The underlying principle of a Stirling cycle engine is the mechanical realization of the Stirling thermodynamic cycle: isochoric heating of a gas in a cylinder, isothermal expansion of the gas (during which it is acted upon by a driving piston), isochoric cooling, and isothermal compression. Additional background regarding aspects of Stirling cycle machines and improvements thereto is discussed in Hargreaves, The Phillips Stirling Engine (Elsevier, Amsterdam, 1991), which is incorporated herein by reference.

[0256] The principles of operation of a Stirling cycle machine are readily explained with reference to FIGS. 45A-45E, in which like numerals are used to identify like or similar parts. Many mechanical layouts of Stirling cycle machines are known in the art, and a particular Stirling cycle machine, generally designated by the numeral 5110, is shown for illustrative purposes only. In FIGS. 45A through 45D, a piston 5112 and a displacer 5114 move in a stepped reciprocating motion within a cylinder 5116, which may be a single cylinder in some embodiments of a Stirling cycle machine, but may be more than a single cylinder in other embodiments. The working fluid contained within the cylinder 5116 is constrained from leaking around the piston 5112 and the displacer 5114 by a seal. The working fluid is chosen for its thermodynamic properties, as discussed in the following description, and is typically helium at a pressure of several atmospheres, although any gas, including any inert gas, may be used, including, but not limited to, hydrogen, argon, neon, nitrogen, air, and any mixture thereof. The position of the displacer 5114 controls whether the working fluid is in contact with a hot interface 5118 or a cold interface 5120, which correspond to the interfaces where heat is supplied to and extracted from the working fluid, respectively. Heat supply and extraction are discussed in more detail below. The volume of working fluid that is controlled by the position of the piston 5112 is called the compression space 5122.

[0257] During the first phase of the Stirling cycle, whose starting state is shown in FIG. 45A, the piston 5112 compresses the fluid in the compression space 5122. Compression occurs at a substantially constant temperature because heat is extracted from the fluid to the surrounding environment. The state of the Stirling cycle machine 5110 after compression is shown in FIG. 45B. During the second phase of the cycle, the displacer 5114 moves toward the cold interface 5120, displacing the working fluid from the region of the cold interface 5120 to the region of the hot interface 5118. This stage may be referred to as the transfer phase. At the end of the transfer phase, the working fluid is heated at constant volume, resulting in a higher pressure. The increased pressure is symbolically represented in FIG. 45C by the reading of the pressure gauge 5124.

[0258] During the third phase (expansion stroke) of the Stirling cycle machine, the volume of the compression space 5122 increases as heat is received from outside the Stirling cycle machine 5110, thereby converting the heat into work. In practice, heat is provided to the fluid using a heater head (not shown), which will be discussed in more detail below. At the end of the expansion phase, the compression space 5122 is filled with cold fluid, as shown in FIG. 45D. During the fourth phase of the Stirling cycle machine 5110, fluid is transferred from the region of the hot interface 5118 to the region of the cold interface 5120 by the movement of the displacer 5114 in the opposite direction. At the end of this second transfer phase, the fluid fills the compression space 5122 and the cold interface 5120, as shown in FIG. 45A, and is ready for a repeat of the compression phase. The Stirling cycle is illustrated in a pressure-volume (PV) diagram, as shown in FIG. 45E.

[0259] Additionally, upon passing from the region of the hot interface 5118 to the region of the cold interface 5120, in some embodiments the fluid may pass through a regenerator (shown as 5408 in FIG. 48). The regenerator is a matrix-like material with a large surface area to volume ratio that absorbs heat from the fluid as it enters from the region of the hot interface 5118 and heats the fluid as it passes from the region of the cold interface 5120.

[0260] Stirling cycle machines have generally not been used in practical applications due to several challenges to their development, including practical considerations such as efficiency and lifespan. Thus, there is a need for more Stirling cycle machines with minimal side loads on the pistons, increased efficiency, and lifespan. (Rocking beam drive) 46-48, an embodiment of a Stirling cycle machine is shown in cross section according to one embodiment. The engine embodiment is generally designated by the numeral 5300. While the Stirling cycle machine will generally be described with reference to the Stirling engine 5300 embodiment shown in FIGS. 46-48, it should be understood that many types of machines and engines, including but not limited to refrigerators and compressors, may similarly benefit from the various embodiments and improvements described herein, including but not limited to external combustion engines and internal combustion engines.

[0261] FIG. 46 shows a cross section of an embodiment of a rocking beam drive mechanism 5200 (the term "rocking beam drive" is used interchangeably with "rocking beam drive") for an engine, such as a Stirling engine, having linearly reciprocating pistons 5202 and 5204 housed within cylinders 5206 and 5208, respectively. The cylinders contain linear bearings 5220. Rocking beam drive 5200 converts the linear motion of pistons 5202 and 5204 into rotational motion of a crankshaft 5214. Rocking beam drive 5200 has a rocking beam 5216, a rocker pivot 5218, a first linkage assembly 5210, and a second linkage assembly 5212. Pistons 5202 and 5204 are coupled to rocking beam drive 5200 via first linkage assembly 5210 and second linkage assembly 5212, respectively. The rocking beam drive is connected to the crankshaft 5214 via a connecting rod 5222 .

[0262] In some embodiments, the rocking beam and a first portion of the linkage assembly may be located within the crankcase, while the cylinder, piston, and a second portion of the linkage assembly are located within the workspace.

[0263] In the crankcase 5400 of FIG. 48 , most of the rocking beam drive 5200 is located below the cylinder housing 5402. The crankcase 5400 provides a space that allows movement of the rocking beam drive 5200, which includes the crankshaft 5214, rocking beam 5216, linear bearing 5220, connecting rod 5222, and linkage assemblies 5210 and 5212. The crankcase 5400 intersects the cylinders 5206 and 5208 perpendicular to the plane of the axes of the pistons 5202 and 5204. The pistons 5202 and 5204 reciprocate within their respective cylinders 5206 and 5208, as also shown in FIG. 46 . The cylinders 5206 and 5208 extend above the crankshaft housing 5400. The crankshaft 5214 is mounted within the crankcase 5400 below the cylinders 5206 and 5208.

[0264] 46 shows one embodiment of a rocking beam drive 5200. Linkage assemblies 5210 and 5212 extend from pistons 5202 and 5204, respectively, and connect pistons 5202 and 5204 to a rocking beam 5216. Linkage assembly 5212 for piston 5204, in some embodiments, may include a piston rod 5224 and a link rod 5226. Linkage assembly 5210 for piston 5202, in some embodiments, may include a piston rod 5228 and a link rod 5230. Piston 5204 moves vertically within a cylinder 5208 and is connected to an end pivot 5232 of rocking beam 5216 by linkage assembly 5212. Cylinder 5208 provides guidance for longitudinal movement of piston 5204. The piston rod 5224 of the linkage assembly 5212, which is attached to the lower portion of the piston 5204, is driven longitudinally by its link rod 5226 in a substantially straight, reciprocating path along the axis of the cylinder 5208. The distal end of the piston rod 5224 and the proximal end of the link rod 5226, in some embodiments, are co-hinged via a linkage 5234. The linkage 5234 may be any linkage known in the art, including, but not limited to, a flexible joint, a roller bearing element, a hinge, a journal bearing joint (shown as 5600 in FIG. 50), and a flexure (shown as 5700 in FIGS. 51A and 51B). The distal end of the link rod 5226 may be connected to one end pivot 5232 of the rocking beam 5216, which is positioned vertically and upright below the proximal end of the link rod 5226. The stationary linear bearing 5220 may be disposed along the linkage assembly 5212 to further ensure substantially straight longitudinal movement of the piston rod 5224, and thus, the piston 5204. In an exemplary embodiment, the link rod 5226 does not pass through the linear bearing 5220. This, among other things, ensures that the piston rod 5224 retains substantially straight longitudinal movement.

[0265] In an exemplary embodiment, the link rods may be made of aluminum, and the piston rods and connecting rods are made of D2 tool steel. Alternatively, the link rods, piston rods, connecting rods, and rocking beam may be made of 4340 steel. Other materials may be used for the rocking beam drive components, including, but not limited to, titanium, aluminum, steel, or cast iron. In some embodiments, the fatigue strength of the materials used is equal to or exceeds the actual loads experienced by the components during operation.

[0266] 46-48 , the piston 5202 moves vertically within a cylinder 5206 and is connected to an end pivot 5236 of a rocking beam 5216 by a linkage assembly 5210. The cylinder 5206 serves, among other things, to provide guidance for the longitudinal movement of the piston 5202. A piston rod 5228 of the linkage assembly 5210 is attached to a lower portion of the piston 5202 and is driven axially by its link rod 5230 in a substantially straight, reciprocating path along the axis of the cylinder 5206. The distal end of the piston rod 5228 and the proximal end of the link rod 5230 are, in some embodiments, co-hinged via a linkage 5238. The linkage 5238, in various embodiments, may include, but is not limited to, a flexure (shown as 5700 in FIGS. 51A and 51B ), a roller bearing element, a hinge, a journal bearing joint (shown as 5600 in FIG. 50 ), or any other such linkage known in the art. The distal end of link rod 5230 may, in some embodiments, be coupled to one end pivot 5236 of rocking beam 5216, which is disposed vertically and upright below the proximal end of link rod 5230. A stationary linear bearing 5220 may be disposed along linkage assembly 5210 to further ensure substantially straight longitudinal movement of piston rod 5228, and thus piston 5202. In an exemplary embodiment, link rod 5230 does not pass through linear bearing 5220, so as to ensure that piston rod 5228 retains substantially straight longitudinal movement.

[0267] Linkage assemblies 5210 and 5212 transform the alternating longitudinal motion of respective pistons 5202 and 5204 into oscillatory motion of rocking beam 5216. The delivered oscillatory motion is transformed into rotational motion of crankshaft 5214 by connecting rod 5222, one end of which is rotatably coupled to connecting pivot 5240 located on rocking beam 5216 between end pivot 5232 and rocker pivot 5218, and the other end of which is rotatably coupled to crank pin 5246. Rocker pivot 5218 is located substantially midway between end pivots 5232 and 5236 and oscillatorily supports rocking beam 5216 as a fulcrum, thus may induce the respective piston rods 5224 and 5228 to undergo sufficient linear motion. In the exemplary embodiment, the crankshaft 5214 is located above the rocking beam 5216, however, in other embodiments, the crankshaft 5214 may be located below the rocking beam 5216 (as shown in FIGS. 49B and 49D), or in some embodiments, the crankshaft 5214 is located to the side of the rocking beam 5216 so as to still have a parallel axis to the rocking beam 5216.

[0268] 46-48, the rocking beam oscillates about rocker pivot 5218, causing end pivots 5232 and 5236 to follow an arcuate path. Because the distal ends of link rods 5226 and 5230 are connected to rocking beam 5216 at pivots 5232 and 5236, the distal ends of link rods 5226 and 5230 also follow this arcuate path, resulting in angular deviations 5242 and 5244 from the longitudinal axes of motion of respective pistons 5202 and 5204. Couplings 5234 and 5238 are configured such that any angular deviations 5242 and 5244 experienced by piston rods 5224 and 5228 from link rods 5226 and 5230 are minimized. Essentially, angular deviations 5244 and 5242 are absorbed by linkage means 5234 and 5238 such that piston rods 5224 and 5228 maintain substantially straight longitudinal motion, reducing side loads on pistons 5204 and 5202. A stationary linear bearing 5220 may also be positioned inside cylinder 5208 or 5206 or along linkage assembly 5212 or 5210 to further absorb any angular deviations 5244 or 5242 and thus keep piston push rod 5224 or 5228 and piston 5204 or 5202 in linear motion along the longitudinal axis of piston 5204 or 5202.

[0269] Therefore, considering the reciprocating motion of pistons 5202 and 5204, it is necessary to keep the motion of pistons 5202 and 5204 as close to a straight line as possible, because deviations 5242 and 5244 from the longitudinal axis of the reciprocating motion of pistons 5202 and 5204 cause noise, reduced efficiency, increased friction against the cylinder walls, increased side loads, and reduced component durability. Thus, the alignment of cylinders 5206 and 5208 and the arrangement of crankshaft 5214, piston rods 5224 and 5228, link rods 5226 and 5230, and connecting rod 5222, among other things, can affect the efficiency and / or volume of the device. As mentioned above, with the objective of increasing the straightness of piston motion, the pistons (shown as 5202 and 5204 in FIGS. 46-48 ) are preferably located as close as possible to the sides of their respective cylinders 5206 and 5208.

[0270] In another embodiment for reducing the angular deviation of the link rods, the link rods 5226 and 5230 reciprocate substantially linearly along the longitudinal axis of the respective pistons 5204 and 5202 to reduce the angular deviation and, therefore, reduce the side load imparted to each piston 5204 and 5202. The angular deviation defines the deviation of the link rods 5226 or 5230 from the longitudinal axis of the pistons 5204 or 5202. Numerals 5244 and 5242 refer to the angular deviation of the link rods 5226 and 5230 as shown in FIG. 46 . Thus, the position of the link assembly 5212 affects the angular displacement of the link rod 5226 based on the length of the distance between the end pivot 5232 and the rocker pivot 5218 of the rocking beam 5216. Thus, the position of the link assembly may be such that the angular deviation of the link rod 5226 is reduced. For link rod 5230, the length of link assembly 5210 may also be determined and positioned to reduce angular deviation of link rod 5230 based on the length of the distance between end pivot 5236 and rocker pivot 5218 of rocking beam 5216. Thus, the lengths of link rods 5226 and 5230, the lengths of link assemblies 5212 and 5210, and the length of rocking beam 5216 are important parameters that significantly influence and / or determine the angular deviation of link rods 5226 and 5230 as shown in FIG.

[0271] The exemplary embodiment has a straight rocking beam 5216 with end points 5232 and 5236, a rocker pivot 5218, and a connecting pivot 5240 along the same axis. However, in other embodiments, the rocking beam 5216 may be curved such that the pistons may be disposed at an angle relative to one another, as shown in Figures 49C and 49D.

[0272] 46-48 and 51A-51B, in some embodiments of the linkage assembly, the linkage assemblies 5212 and 5210 may include flexible link rods that are axially stiff but flexible within the rocking beam 5216 plane of motion between the link rods 5226 and 5230 and the pistons 5204 and 5202, respectively. In this embodiment, at least a portion of the link rods 5226 and 5230, a flexure (shown as 5700 in FIGS. 51A and 51B), is elastic. The flexure 5700 serves as a coupling means between the piston rod and the link rod. The flexure 5700 may more effectively absorb crank-induced side loads on the pistons, thus allowing the respective pistons to maintain linear axial motion within their cylinders. The flexure 5700 allows for small rotation within the rocking beam 5216 plane between the link rods 5226 and 5230 and the pistons 5204 or 5202, respectively. Although shown as flat in this embodiment, which increases the resilience of link rods 5226 and 5230, bends 5700 are not flat in some embodiments. Bends 5700 may also be constructed near the lower portion of the piston or near the distal ends of link rods 5226 and 5230. Bends 5700 may be made of #D2 tool steel, high strength 58-62RC, in one embodiment. In some embodiments, there may be two or more bends (not shown) on link rods 5226 or 5230 to increase the resilience of the link rods.

[0273] In alternative embodiments, the axes of the pistons in each cylinder housing may extend in different directions, as shown in Figures 49C and 49D. In an exemplary embodiment, the axes of the pistons in each cylinder housing are substantially parallel, and preferably substantially perpendicular, as shown in Figures 46-48 and Figures 55A and 55B. Figures 49A-49D include various embodiments of rocking beam drive mechanisms, including like numbers, as shown and described with respect to Figures 2-4. It will be understood by those skilled in the art that varying the relative position of the connecting pivot 5240 along the rocking beam 5216 will vary the stroke of the pistons.

[0274] Thus, varying the relative position of connecting pivot 5240 in rocking beam 5216, as well as the parameters of piston rods 5224 and 5228, link rods 5230 and 5226, length of rocking beam 5216, and length of rocker pivot 5218, varies the angular deviation of link rods 5226 and 5230, the phase of pistons 5204 and 5202, and the size of device 5300 in various ways. Thus, in various embodiments, a wide range of piston phase angles and variable engine sizes may be selected based on modifying one or more of these parameters. In practice, link rods 5224 and 5228 in the exemplary embodiment have a substantial lateral movement within −0.5 to +0.5 degrees from the longitudinal axis of pistons 5204 and 5202. In various other embodiments, depending on the length of the link rods, the angle may vary between approximately 0 and 0.75 degrees. However, in other embodiments, the angle may be even higher, including between approximately 0 and 20 degrees. However, as the link rod length increases, the crankcase / overall engine height increases, as does the weight of the engine.

[0275] One feature of the exemplary embodiment is that each piston has a link rod that extends substantially to an associated piston rod to form a linkage assembly. In one embodiment, the linkage assembly 5212 for the piston 5204 includes a piston rod 5224, a link rod 5226, and a linkage 5234, as shown in FIG. 46 . More specifically, one proximal end of the piston rod 5224 is attached to a lower portion of the piston 5204, and a distal end of the piston rod 5224 is connected to a proximal end of the link rod 5226 by a linkage 5234. The distal end of the link rod 5226 extends perpendicularly to an end pivot 5232 of the rocking beam 5216. As noted above, the linkage 5234 may be, but is not limited to, a joint, hinge, link, or flexure, or other means known in the art. In this embodiment, the ratio of piston rod 5224 to link rod 5226 may determine the angular deviation of link rod 5226 as described above.

[0276] In one embodiment of the machine, an engine, such as a Stirling engine, employs two or more rocking beam drives on a crankshaft. Referring now to FIG. 52 , an uncoated “four-cylinder” rocking beam drive mechanism 5800 is shown. In this embodiment, the rocking beam drive mechanism has four pistons 5802, 5804, 5806, and 5808 coupled to two rocking beam drives 5810 and 5812. In the exemplary embodiment, rocking beam drive mechanism 5800 is used in a Stirling engine with at least four pistons 5802, 5804, 5806, and 5808 arranged in a quadrilateral arrangement coupled to a pair of rocking beam drives 5810 and 5812, with each rocking beam drive connected to a crankshaft 5814. However, in other embodiments, the Stirling cycle engine includes between one and four pistons, and in still other embodiments, the Stirling cycle engine includes five or more pistons. In some embodiments, rocking beam drives 5810 and 5812 are substantially similar to the rocking beam drives described above with respect to Figures 46-48 (shown as 5210 and 5212 in Figures 46-48). In this embodiment, the piston is shown outside the cylinder, but in reality the piston would be inside the cylinder.

[0277] 52 , in some embodiments, the rocking beam drive mechanism 5800 has a single crankshaft 5814 having a pair of longitudinally spaced, radially opposed crankpins 5816 and 5818 adapted to be journaled within a housing, and a pair of rocking beam drives 5810 and 5812. Each rocking beam 5820 and 5822 is pivotally connected to a rocker pivot 5824 and 5826, respectively, and to the crankpins 5816 and 5818, respectively. In the exemplary embodiment, the rocking beams 5820 and 5822 are coupled to the rocking beam shaft 5828.

[0278] In some embodiments, a motor / generator may be connected in operative relationship to the crankshaft. The motor may be located between the rocking beam drives in one embodiment. In another embodiment, the motor may be located externally. The term "motor / generator" is used to mean either a motor or a generator.

[0279] Figure 53 shows one embodiment of a crankshaft 5814. Disposed on the crankshaft is a motor / generator 5900, such as a permanent magnet ("PM") generator. The motor / generator 5900 may be located between or within the rocking beam drives (not shown, shown in Figure 53 as 5810 and 5812), or may be located outside or external to the rocking beam drives 5810 and 5812 at the end of the crankshaft 5814, as shown by the numeral 51000 in Figure 54A.

[0280] When the motor / generator 5900 is placed between the rocking beam drives (not shown, shown in FIG. 52 as 5810 and 5812), the length of the motor / generator 5900 is limited to the distance between the rocking beam drives. The square of the diameter of the motor / generator 5900 is limited by the distance between the crankshaft 5814 and the rocking beam axis 5828. Because the capacity of a motor / generator 5900 is proportional to the square of its diameter and its length, these dimensional limitations result in a limited-capacity "pancake" motor / generator 5900 having a relatively short length and a relatively large square of the diameter. While the use of a "pancake" motor / generator 5900 may reduce the overall size of the engine, the dimensional limitations imposed by the internal configuration result in a motor / generator with a limited capacity.

[0281] Locating the motor / generator 5900 between the rocking beam drives exposes the motor / generator 5900 to heat generated by the mechanical friction of the rocking beam drives. The onboard location of the motor / generator 5900 makes it more difficult to cool the motor / generator 5900, thereby increasing the effect of heat produced by the motor / generator 5900 as well as heat absorbed by the motor / generator 5900 from the rocking beam drives. This can lead to overheating and ultimately failure of the motor / generator 5900.

[0282] Referring to both Figures 52 and 53, the internal arrangement of motor / generator 5900 may also lead to a non-equilateral configuration of pistons 5802, 5804, 5806, and 5808 as pistons 5802, 5804, 5806, and 5808 are coupled to rocking beam drives 5810 and 5812, respectively, and an increase in the distance also results in an increase in the distance between pistons 5802 and 5804 and pistons 5806 and 5808. Non-equisceles piston placement can lead to inefficient thermodynamic operation of the combustor and heater head, which in turn can lead to reduced overall engine efficiency. Additionally, non-equisceles piston placement can lead to larger heater head and combustion chamber dimensions.

[0283] An exemplary embodiment of a motor / generator arrangement is shown in FIG. 54A. As shown in FIG. 54A, the motor / generator 51000 is located externally from the rocking beam drives 51010 and 51012 (shown as 5810 and 5812 in FIG. 52) and at the end of the crankshaft 51006. The external location allows the motor / generator 51000 to have a larger length and squared diameter than the "pancake" motor / generator (shown as 5900 in FIG. 53) described above. As previously mentioned, the capacity of the motor / generator 51000 is proportional to the squared length and diameter, and because the external motor / generator 51000 may have a larger length and squared diameter, the configuration of the external motor / generator 51000 shown in FIG. 54A may allow the use of a higher capacity motor / generator in conjunction with an engine.

[0284] By locating the motor / generator 51000 external to the drive sections 51010 and 51012, as shown in the embodiment of Figure 54A, the motor / generator 51000 is not exposed to heat generated by mechanical friction between the drive sections 51010 and 51012. The external location of the motor / generator 51000 also facilitates further cooling of the motor / generator, thereby allowing for more mechanical engine cycles for a given amount of time, which in turn allows for higher overall engine performance.

[0285] Also, because the motor / generator 51000 is located outboard and not between the drives 51010 and 51012, the rocking beam drives 51010 and 51012 may be located closer together, thereby allowing the pistons coupled to the drives 51010 and 51012 to be arranged in an equilateral arrangement. In some embodiments, depending on the type of combustor used, particularly in single-combustor embodiments, an equilateral arrangement of the pistons allows for greater efficiency in the thermodynamic operation of the combustor and heater head, which in turn allows for higher overall engine performance. An equilateral arrangement of the pistons also advantageously allows for smaller heater head and combustion chamber sizes.

[0286] Referring again to FIGS. 52 and 53 , crankshaft 5814 may have concentric ends 5902 and 5904, which in one embodiment are crank journals and may be bearings in various other embodiments, but are not limited to such. Each concentric end 5902, 5904 has a crank pin 5816, 5818, respectively, which may be offset from the central axis of the crankshaft. At least one counterweight 5906 may be located at either end of crankshaft 5814 (shown as 5806 in FIG. 54A ) to counterbalance any instability that crankshaft 581 may experience. This crankshaft configuration, combined with the rocking beam drive described above, allows the pistons (shown as 5802, 5804, 5806, and 5808 in FIG. 52 ) to engage with one rotation of crankshaft 5814. This feature is described further below. In other embodiments, a flywheel (not shown) may be disposed on the crankshaft 5814 (shown as 51006 in FIG. 54A) to reduce fluctuations in angular velocity for a more constant speed.

[0287] 52 and 53, in some embodiments, a cooler (not shown) may also be disposed along the crankshaft 5814 (shown as 51006 in FIG. 54A) and the rocking beam drives 5810 and 5812 (shown as 51010 and 51012 in FIG. 54A) to cool the crankshaft 5814 and the rocking beam drives 5810 and 5812. In some embodiments, the cooler may be used to cool the working gas in the cryo-chamber of the cylinder and may also be configured to cool the rocking beam drives. Various embodiments of the cooler are discussed in detail below.

[0288] 54A-54G show several embodiments of the various components of the machine. As shown in this embodiment, the crankshaft 51006 is coupled to the motor / generator 51000 via a motor / generator linkage assembly. Because the motor / generator 51000 is attached to the crankcase 51008, pressurization of the crankcase with input fluid may result in deformation of the crankcase, which may in turn lead to misalignment between the motor / generator 51000 and the crankshaft 51006, causing the crankshaft 51006 to deflect. Because the rocking beam drives 51010 and 51012 are coupled to the crankshaft 51006, deflection of the crankshaft 51006 may lead to failure of the rocking beam drives 51010 and 51012. Therefore, in one embodiment of the machine, a motor / generator linkage assembly is used to couple the motor / generator 51000 to the crankshaft 51006. The motor / generator linkage assembly accommodates differences in alignment between the motor / generator 51000 and the crankshaft 51006 that may contribute to failure of the rocking beam drives 51010 and 51012 during operation.

[0289] Still referring to Figures 54A-54G, in one embodiment, the motor / generator coupling assembly is a splined assembly including a splined shaft 51004, a sleeve rotor 51002 of the motor / generator 51000, and a crankshaft 51006. The splined shaft 51004 couples one end of the crankshaft 51006 to the sleeve rotor 51002. The sleeve rotor 51002 is attached to the motor / generator 51000 by mechanical means such as a press fit, welding, threaded engagement, or the like. In one embodiment, the splined shaft 51004 includes multiple splines on both ends of the shaft. In other embodiments, the splined shaft 51004 includes an intermediate unsplined portion 51014 having a diameter smaller than the outer or inner diameters of the splined portions 51016 and 51018. In yet other embodiments, one end portion of the splined shaft 51016 has splines that extend a greater distance along the shaft than a second end portion 51018 that also includes splines thereon.

[0290] In some embodiments, the sleeve rotor 51002 includes an opening 51020 extending along a longitudinal axis of the sleeve rotor 51002. The opening 51020 is capable of receiving the splined shaft 51004. In some embodiments, the opening 51020 includes a plurality of internal splines 51022 that are capable of engaging splines on one end of the splined shaft 51004. An outer diameter 51028 of the internal splines 51022 may be larger than an outer diameter 51030 of the splines on the splined shaft 51004 such that there is a loose fit between the internal splines 51022 and the splines on the splined shaft 51004 (as shown in FIG. 54E ). The loose fit between the internal splines 51022 and the splines on the splined shaft 51004 helps maintain the splined engagement between the splined shaft 51004 and the rotor sleeve 51002 during deflection of the splined shaft 51004, which may be caused by crankcase pressurization. In other embodiments, a longer splined portion 51016 of the splined shaft 51004 may engage the internal splines 51022 of the rotor 51002.

[0291] 54A-54G, in some embodiments, the crankshaft 51006 has an opening 51024 on an end thereof capable of receiving one end of the splined shaft 51004. The opening 51024 preferably includes a plurality of internal splines 51026 that engage with splines on the splined shaft 51004. The outer diameter 51032 of the internal splines 51026 may be larger than the outer diameter 51034 of the splines on the splined shaft 51004 so that there is a loose fit between the internal splines 51026 and the splines on the splined shaft 51004 (as shown in FIG. 54F). As previously mentioned, the loose fit between the internal splines 51026 and the splines on the splined shaft 51004 contributes to maintaining splined engagement between the splined shaft 51004 and the crankshaft 51006 during deflection of the splined shaft 51004, which may be caused by crankcase pressurization. The loose fit between the internal splines 51026 and 51022 on the crankshaft 51006 and sleeve rotor 51002 and the splines on the splined shaft 51004 may contribute to maintaining deflection of the splined shaft 51004. This may allow for misalignment between the crankshaft 51006 and the sleeve rotor 51002. In some embodiments, the shorter splined portion 51018 of the splined shaft 51004 may engage the opening 51024 in the crankshaft 51006, thus preventing these potential misalignments.

[0292] In some embodiments, the opening 51020 of the sleeve rotor 51002 includes a plurality of internal splines that extend the length of the opening 51020. This arrangement helps ensure that the splined shaft 51004 is properly inserted into the opening 51020 during assembly. This helps maintain proper alignment between the splines on the splined shaft 51004 and the internal splines on the sleeve rotor 51002.

[0293] Referring now to FIG. 48, one embodiment of an engine is shown. Here, pistons 5202 and 5204 of engine 5300 operate between hot and cold chambers 5404 and 5406 of cylinders 5206 and 5208, respectively. Between the two chambers may be a regenerator 5408. The regenerator 5408 may have a variable density and / or a variable area, and in some embodiments, is made of wire. The variable density and area of ​​the regenerator may be adjusted so that the working gas has a substantially uniform flow throughout the regenerator 5408. Various embodiments of the regenerator 5408 are discussed in detail below and in U.S. Patent No. 6,591,609, issued July 17, 2003 to Kamen et al., and U.S. Patent No. 6,862,883, issued March 8, 2005 to Kamen et al., which are incorporated herein by reference in their entireties. As the working gas passes through the hot chamber 5404, the heater head 5410 may heat the gas, causing it to expand and push the pistons 5202 and 5204 towards the cold chamber 5406 where it compresses. As the gas compresses in the cold chamber 5406, the pistons 5202 and 5204 may be pulled back into the hot chamber to undergo the Stirling cycle again. The heater head 5410 may be a pin head, a fin head, a folded fin head, a heater tube as shown in FIG. 48, or any other known heater head embodiment, including but not limited to those described below. Various embodiments of the heater head 5410 are discussed in detail below and in U.S. Pat. No. 6,381,958 issued May 7, 2002 to Kamen et al., U.S. Pat. No. 6,543,215 issued April 8, 2003 to Langenfeld et al., U.S. Pat. No. 6,966,182 issued November 22, 2005 to Kamen et al., and U.S. Pat. No. 7,308,787 issued December 18, 2007 to LaRocque et al., which are incorporated herein by reference in their entireties.

[0294] In some embodiments, a cooler 5412 may be positioned alongside cylinders 5206 and 5208 to further cool the gas passing through cryochamber 5406. Various embodiments of cooler 5412 are discussed in detail in subsequent sections and in U.S. Patent No. 7,325,399, issued February 5, 2008 to Strimling et al., which is incorporated herein by reference in its entirety.

[0295] In some embodiments, at least one piston seal 5414 may be disposed on pistons 5202 and 5204 to seal hot section 5404 from cold section 5406. Additionally, at least one piston guide ring 5416 may be disposed on pistons 5202 and 5204 to help guide the movement of the pistons within their respective cylinders. Various embodiments of piston seals 5414 and guide rings 5416 are described in detail below and in U.S. patent application Ser. No. 10 / 175,502, filed July 19, 2002, issued February 6, 2003 (now abandoned), which is incorporated herein by reference in its entirety.

[0296] In some embodiments, at least one piston rod seal 5418 may be positioned against the piston rods 5224 and 5228 to prevent working gas from leaking into the crankcase 5400, or alternatively, into the airlock space 5420. The piston rod seal 5418 may be an elastomeric seal or a spring-loaded seal. Various embodiments of the piston rod seal 5418 are discussed in detail below.

[0297] In some embodiments, the airlock space may be eliminated, for example, in rolling diaphragm and / or bellows embodiments described in more detail below. In such cases, piston rod seals 5224 and 5228 seal the working space from the crankcase.

[0298] In some embodiments, at least one rolling diaphragm / bellows 5422 may be located along the piston rods 5224 and 5228 to prevent airlock gas from leaking into the crankcase 5400. Various embodiments of the rolling diaphragm 5422 are discussed in detail below.

[0299] While FIG. 48 shows a cross section of engine 5300 showing only two pistons and one rocking beam drive, it should be understood that the principles of operation described herein may also apply to a four-cylinder dual rocking beam drive engine, such as generally indicated by the numeral 5800 in FIG. 58. (piston movement) 52 and 55, there is shown the movement of pistons 5802, 5804, 5806, and 5808 during one revolution of crankshaft 5814. Through a quarter revolution of crankshaft 5814, piston 5802 is at the top of the cylinder, otherwise known as top dead center, piston 5806 is at its upward mid-stroke, piston 5804 is at the bottom of the cylinder, otherwise known as bottom dead center, and piston 5808 is at its downward mid-stroke. Through a half revolution of crankshaft 5814, piston 5802 is at its downward mid-stroke, piston 5806 is at its top dead center, piston 5804 is at its upward mid-stroke, and piston 5808 is at its bottom dead center. Through three-quarters of a revolution of crankshaft 5814, piston 5802 is at bottom dead center, piston 5806 is at its downward mid-stroke, piston 5804 is at its top dead center, and piston 5808 is at its upward mid-stroke. Finally, through a full revolution of crankshaft 5814, piston 5802 is at its upward stroke, piston 5806 is at bottom dead center, piston 5804 is at its downward mid-stroke, and piston 5808 is at top dead center. During each quarter revolution, there is a 90-degree phase difference between pistons 5802 and 5806, a 180-degree phase difference between pistons 5802 and 5804, and a 270-degree phase difference between pistons 5802 and 5808. FIG. 56A illustrates the relationship of the pistons to be approximately 90 degrees out of phase with the leading and trailing pistons. Additionally, FIG. 55 shows the mechanical means of transmission of an exemplary embodiment. Thus, a full rotation of crankshaft 5814 transfers action from piston 5802 to piston 5806 to piston 5804 to piston 5808 such that all pistons exert action by moving from the top to the bottom of their respective cylinders.

[0300] Referring now to FIG. 55 in conjunction with FIGS. 56A-56C, a 90-degree phase difference between pistons in an exemplary embodiment is illustrated. Referring now to FIG. 56A, while the cylinders are shown in linear paths, this is for illustrative purposes only. In an exemplary embodiment of a four-cylinder Stirling cycle machine, the flow path of the working gas contained within the cylinder working spaces follows a figure-eight pattern. Thus, the working spaces of cylinders 51200, 51202, 51204, and 51206 are connected in a figure-eight pattern, for example, from cylinder 51200 to cylinder 51202 to cylinder 51204 to cylinder 51208, such that the fluid flow pattern follows a figure-eight. Still referring to FIG. 56A, an uncoated view of cylinders 51200, 51202, 51204, and 51206 is shown taken along line BB (shown in FIG. 56C). A 90-degree phase difference between the pistons as described above allows the working gas in the warm section 51212 of cylinder 51204 to be delivered to the cold section 51222 of cylinder 51206. When pistons 5802 and 5808 are 90 degrees out of phase, the working gas in the warm section 51214 of cylinder 51206 is delivered to the cold section 51216 of cylinder 51200. When pistons 5802 and 5806 are also 90 degrees out of phase, the working gas in the warm section 51208 of cylinder 51200 is delivered to the cold section 51218 of cylinder 51202. When pistons 5804 and 5806 are also 90 degrees out of phase, the working gas in the warm section 51210 of cylinder 51202 is delivered to the cold section 51220 of cylinder 51204. Once the working gas in the warm section of the first cylinder enters the cold section of the second cylinder, the working gas begins to compress, and then the piston in the second cylinder on its downward stroke pushes the compressed working gas back through the regenerator 51224 and heater head 51226 (shown in FIG. 56B) and back into the warm section of the first cylinder. Once inside the warm section of the first cylinder, the gas expands, driving the piston in that cylinder and thus driving the working gas in the cold section of the first cylinder, through the previous regenerator and heater head, and into the cylinder.This cyclical movement characteristic of the working gas between cylinders 51200, 51202, 51204, and 51206 is possible because pistons 5802, 5804, 5806, and 5808 are connected to a common crankshaft 5814 (shown in FIG. 55) via drives 5810 and 5812 in such a way that the circular movement of each piston is approximately 90 degrees prior to the movement of the previous piston, as shown in FIG. 56A. (Rolling diaphragms, metal bellows, airlocks, and pressure regulators) In some embodiments of Stirling cycle machines, a lubricating fluid is used, and seals are used to prevent the lubricating fluid from leaking out of the crankcase.

[0301] Referring now to FIGS. 57A-59, some embodiments of a Stirling cycle machine include a fluid-lubricated rocking beam drive that utilizes a rolling diaphragm 51300 positioned along the piston rod 51302 to prevent lubrication fluid from leaking from the crankcase (not shown, but components housed in the crankcase are represented as 51304) and ingress areas of the engine that may be damaged by the lubrication fluid. Containing the lubrication fluid is beneficial because if the lubrication fluid enters the working space (not shown, but components housed in the working space are represented as 51306), it could contaminate the working fluid, contact the regenerator 51308, and clog the regenerator 51308. The rolling diaphragm 51300 may be made of an elastomeric material, such as rubber or rubber reinforced with a woven or nonwoven fabric to provide rigidity. The rolling diaphragm 51300 may alternatively be made of other materials, such as fluorosilicone or nitrile, with a woven or nonwoven fabric. The rolling diaphragm 51300 may also be made of carbon nanotubes or shredded fabric, such as a nonwoven fabric with polyester or KEVLAR® fibers dispersed in an elastomer. In some embodiments, the rolling diaphragm 51300 is supported by a top sealing piston 51328 and a bottom sealing piston 51310. In other embodiments, the rolling diaphragm 51300 as shown in FIG. 57A is supported via notches in the top sealing piston 51328.

[0302] In some embodiments, a pressure differential is placed across the rolling diaphragm 51300 so that the pressure above the seal 51300 is different from the pressure in the crankcase 51304. This pressure differential causes the seal 51300 to expand, allowing the seal 51300 to act as a dynamic seal, as the pressure differential ensures that the rolling diaphragm maintains its shape throughout operation. Figures 57A and 57C-57H illustrate how the pressure differential affects the rolling diaphragm. As it moves with the piston rod 51302, the pressure differential causes the rolling diaphragm 51300 to conform to the shape of the bottom sealing piston 51310, preventing separation of the seal 51300 from the surface of the piston 51310 during operation. Such separation could cause the seal to fail. The pressure differential causes the rolling diaphragm 51300 to maintain constant contact with the bottom sealing piston 51310 as it moves with the piston rod 51302. This occurs because one side of the seal 51300 always has pressure exerted on it, thereby expanding the seal 51300 to conform to the surface of the bottom sealing piston 51310. In some embodiments, the top sealing piston 51328 "rolls over" the corner of the rolling diaphragm 51300 that is in contact with the bottom sealing piston 51310 to further maintain the seal 51300 in contact with the bottom sealing piston 51310. In an exemplary embodiment, the pressure differential is in the range of 10-15 PSI. There is preferably a smaller pressure in the crankcase 51304 than the pressure differential so that the rolling diaphragm 51300 may expand into the crankcase 51304. However, in other embodiments, the pressure differential may have a larger or smaller range of values.

[0303] The pressure differential may be created by a variety of methods, including, but not limited to, the use of a pressurized lubrication system, a pneumatic pump, a sensor, an electric pump, by vibrating a rocking beam to create a pressure rise in the crankcase 51304, by creating static electricity on the rolling diaphragm 51300, or other similar methods. In some embodiments, the pressure differential is created by pressurizing the crankcase 51304 to a pressure that is below the average pressure in the working space 51306. In some embodiments, the crankcase 51304 is pressurized to a pressure in the range of 10-15 PSI below the average pressure in the working space 51306, although in various other embodiments the pressure differential may be less or greater. Further details regarding rolling diaphragms are included below.

[0304] However, referring now to Figures 57C, 57G, and 57H, another embodiment of a Stirling machine is shown in which an airlock space 51312 is located between the work space 51306 and the crankcase 51304. The airlock space 51312 maintains a constant volume and pressure necessary to create the pressure differential required for the rolling diaphragm 51300 to function as described above. In one embodiment, the airlock 51312 is completely sealed from the work space 51306, so that the pressure in the airlock 51312 is equal to the average pressure in the work space 51306. Thus, in some embodiments, the lack of an effective seal between the work space and the crankcase contributes to the need for an airlock space. Therefore, the airlock space may be eliminated in some embodiments with a more efficient and effective seal.

[0305] During operation, the average pressure in the workspace 51306 may fluctuate, causing the average pressure in the airlock 51312 to fluctuate as well. One reason the pressure may fluctuate is that during operation the workspace may become hotter, which in turn may increase the pressure in the workspace and consequently in the airlock, since the airlock and workspace are in fluid communication. In such cases, the pressure differential between the airlock 51312 and the crankcase 51304 will also fluctuate, thereby causing unnecessary stress in the rolling diaphragm 51300, which may lead to seal failure. Therefore, in some embodiments of the machine, the average pressure in the airlock 51312 is adjusted to maintain a constant desired pressure differential between the airlock 51312 and the crankcase 51304, ensuring that the rolling diaphragm 51300 remains inflated and maintains its shape. In some embodiments, a pressure transducer is used to monitor and manage the pressure differential between the airlock and the crankcase and adjust the pressure accordingly to maintain a constant pressure differential between the airlock and the crankcase. Various embodiments of pressure regulators that may be used are described in further detail below and in U.S. Patent No. 7,310,945, issued December 25, 2007 to Gurski et al., which is incorporated herein by reference in its entirety.

[0306] A constant pressure differential between the airlock 51312 and the crankcase 51304 may be achieved by adding or removing working fluid from the airlock 51312 via a pump or a discharge valve. Alternatively, a constant pressure differential between the airlock 51312 and the crankcase 51304 may be achieved by adding or removing working fluid from the crankcase 51304 via a pump or a discharge valve. The pump and discharge valve may be controlled by a pressure regulator. Working fluid may be added to the airlock 51312 (or crankcase 51304) or transferred from the crankcase 51304 from a separate source, such as a working fluid container. Since the working fluid could cause engine failure if transmitted from the crankcase 51304 to the airlock 51312, it may be desirable to filter the working fluid before it passes into the airlock 51312 to prevent lubricant from passing from the crankcase 51304 into the airlock 51312 and ultimately into the working space 51306.

[0307] In some embodiments of the machine, the crankcase 51304 may be filled with a fluid having different thermal properties than the working fluid. For example, if the working gas is helium or hydrogen, the crankcase may be filled with argon. The crankcase is therefore pressurized; in some embodiments, helium is used, although in other embodiments, any inert gas as described herein may be used. Thus, the crankcase is a wet, pressurized crankcase in the exemplary embodiment. In other embodiments, where no lubricating fluid is used, the crankcase is not wet.

[0308] In exemplary embodiments, the rolling diaphragms 51300 do not allow gases or liquids to pass through them, which allows the working space 51306 to remain dry and the crankcase 51304 to remain wet with lubricating fluid. Allowing a wet-sump crankcase 51304 increases engine efficiency and lifespan due to less friction in the rocking beam drive 51316. In some embodiments, the use of roller or ball bearings in the drive 51316 may also be eliminated with the use of lubricating fluid and the rolling diaphragm 51300. This may further reduce engine noise and increase engine lifespan and efficiency.

[0309] 58A-58E show cross sections of various embodiments of rolling diaphragms (shown as 51400, 51410, 51412, 51422, and 51424) configured to be mounted between top and bottom sealing pistons (shown as 51328 and 51310 in FIGS. 57A and 57H) and between top and bottom mounting surfaces (shown as 51320 and 51318 in FIG. 57A). In some embodiments, the top mounting surface may be a surface of an airlock or workspace, and the bottom mounting surface may be a surface of a crankcase.

[0310] Figure 58A shows one embodiment of a rolling diaphragm 51400, where the rolling diaphragm 51400 includes a flat inner end 51402 that may be positioned between the top and bottom sealing pistons to form a seal between them. The rolling diaphragm 51400 also includes a flat outer end 51404 that may be positioned between the top and bottom mounting surfaces to form a seal between them. Figure 58B shows another embodiment of a rolling diaphragm, where the rolling diaphragm 51410 may include multiple bends 51408 leading to the flat inner end 51406 to provide additional support and sealing contact between the top and bottom sealing pistons. FIG. 58C shows another embodiment of a rolling diaphragm, where a rolling diaphragm 51412 includes multiple bends 51416 leading to a flat outer edge 51414 to provide additional support and sealing contact between the top and bottom mounting surfaces.

[0311] FIG. 58D shows another embodiment of a rolling diaphragm, where the rolling diaphragm 51422 includes a bead along its inner end 51420 to provide an "O-ring" type seal between the top and bottom sealing pistons, and a bead along its outer end 51418 to provide an "O-ring" type seal between the bottom and top mounting surfaces. 58E shows another embodiment of a rolling diaphragm in which the rolling diaphragm 51424 includes multiple bends 51428 that connect to a beaded inner end 51426 to provide additional support and sealing contact between the top and bottom sealing pistons. The rolling diaphragm 51424 may also include multiple bends 51430 that connect to a beaded outer end 51432 to provide additional support and sealing contact between the top and bottom sealing pistons.

[0312] 58A to 58E show various embodiments of rolling diaphragms, it being understood that the rolling diaphragms may be held in place by any other mechanical means known in the art.

[0313] Referring now to FIG. 59A, a cross section shows one embodiment of a rolling diaphragm embodiment. A metal bellows 51500 is positioned along the piston rod 51502 to seal the crankcase (shown as 51304 in FIG. 57G) from the workspace or airlock (shown as 51306 and 51312 in FIG. 57G). The metal bellows 51500 may be attached to the top sealing piston 51504 and a stationary mounting surface 51506. Alternatively, the metal bellows 51500 may be attached to a bottom sealing piston (not shown) and a top stationary mounting surface. In one embodiment, the bottom stationary mounting surface may be a crankcase surface or an inner airlock or workspace surface, and the top stationary mounting surface may be an inner crankcase surface or an outer airlock or workspace surface. The metal bellows 51500 may be attached by welding, brazing, or any mechanical means known in the art.

[0314] 59B-59G show perspective cross-sectional views of various embodiments of a metal bellows, where the metal bellows is a welded metal bellows 51508. In some embodiments of the metal bellows, the metal bellows is preferably a finely welded metal bellows. In some embodiments, the welded metal bellows 51508 includes multiple diaphragms 51510 welded to each other at either the inner end 51512 or the outer end 51514, as shown in FIGS. 59C and 59D. In some embodiments, the diaphragms 51510 may be crescent-shaped 51516, flat 51518, corrugated 51520, or any other shape known in the art.

[0315] Additionally, the metal bellows may alternatively be mechanically formed by means such as die forming, hydroforming, explosive hydroforming, or any other means known in the art.

[0316] Metal bellows may be made of any type of metal, including but not limited to steel, stainless steel, stainless steel 374, AM-350 stainless steel, Inconel, Hastelloy, Haynes, titanium, or high strength corrosion resistant materials.

[0317] In one embodiment, the metal bellows used are available from Senior Aerospace Metal Bellows Division (Sharon, MA) or American BOA, Inc. (Cumming, GA). (Rolling Diaphragm and / or Bellows Embodiments) Various embodiments of rolling diaphragms and / or bellows that function to seal are described above. Further embodiments will be apparent to those skilled in the art based on the above description and the additional description below of the parameters of the rolling diaphragms and / or bellows.

[0318] In some embodiments, the pressure above the rolling diaphragm or bellows in the airlock space or airlock area (both terms are used interchangeably) is the average working gas pressure for the machine, which in some embodiments is an engine, while the pressure below the rolling diaphragm and / or bellows in the crankcase area is ambient / atmospheric pressure. In these embodiments, the rolling diaphragm and / or bellows need to operate across as much as 3000 psi (in some embodiments, up to 1500 psi or more). In this case, the rolling diaphragm and / or bellows seal forms a working gas (helium, hydrogen, or other) containment barrier for the machine (in exemplary embodiments, the engine). Also, in these embodiments, the need for a heavy, pressure-rated structural vessel to contain the bottom end of the engine is eliminated, since it is simply required to contain the lubricating fluid (in exemplary embodiments, oil used as the lubricating fluid) and air at ambient pressure, as in conventional internal combustion (“IC”) engines.

[0319] The ability to use a rolling diaphragm and / or bellows seal with extreme high pressures across it depends on the interplay of several parameters. Referring now to Figure 59H, an illustration of the actual load on the rolling diaphragm or bellows material is shown. As shown, the load is a function of the pressure differential and the annular clearance area for the installed rolling diaphragm or bellows seal.

[0320] Region 1 represents the portion of the rolling diaphragm and / or bellows that is in contact with the wall formed by the piston and cylinder. Due to the pressure difference across the rolling diaphragm and / or bellows, the load is essentially a longitudinal tensile load. This tensile load due to pressure across the rolling diaphragm and / or bellows can be expressed as:

[0321] L t =P d *A a During the ceremony, L t = tensile load P d = pressure difference A a = Annular region and A a =p / 4*(D 2 -d 2 ) During the ceremony, D = cylinder inner diameter d = piston diameter and the tensile component of stress in the bellows material can be approximated as: S t =L t / (π*(D+d)*t b ) This boils down to the following:

[0322] S t =P d / 4*(Dd) / t b Hereafter, we show the relationship between the convolution radius Rc and the cylinder bore diameter (D) and piston diameter (d), which is defined as follows:

[0323] R c =(Dd) / 4 Therefore, the following equation for St reduces to its final form:

[0324] S t =P d *R c / t b During the ceremony, t b = Bellows material thickness is.

[0325] Referring again to Figure 59H, Region 2 represents a convolution. As the rolling diaphragm and / or bellows material turns a corner in a convolution, the hoop stress imposed on the rolling diaphragm and / or bellows material may be calculated. For the portion of the bellows that forms a convolution, the hoop component of stress can be closely approximated as follows:

[0326] S h =P d *R c / t b The annular region within which the rolling diaphragm and / or bellows rolls is generally referred to as the convolution region. The fatigue life of a rolling diaphragm and / or bellows is generally limited by the combined stresses from both the tensile (and hoop) loads due to the pressure differential and the fatigue due to flexing as the fabric rolls through the convolution. The radius that the fabric assumes during this "rolling" is defined herein as the convolution radius, Rc.

[0327] R c =(Dd) / 4 The bending stress Sb in a rolling diaphragm and / or bellows material as it rolls through a convolution radius Rc is a function of that radius as well as the thickness of the material being bent. For fiber-reinforced materials, as the fiber diameter decreases, stress in the fiber itself is relieved (during a given deflection in an exemplary embodiment). The resulting lower stress for the same level of bending allows for an increased fatigue life limit. As the fiber diameter is further reduced, flexibility is achieved to reduce the convolution radius Rc while keeping the bending stress in the fiber below its endurance limit. At the same time, as Rc decreases, the tensile load on the fabric is reduced because there is less unsupported area in the annulus between the piston and cylinder. A smaller fiber diameter results in a smaller minimum Rc and a smaller annulus area, resulting in a higher allowable pressure differential.

[0328] For a bend of said radius, the bending moment is approximated by:

[0329] M=E*I / R During the ceremony, M = bending moment E = Elastic modulus I = moment of inertia R = bending radius is.

[0330] The classical bending stress Sb is calculated as follows:

[0331] S b =M*Y / I During the ceremony, Y = distance above the neutral axis of bending and by substituting, S b =(E*I / R)*Y / I S b =E*Y / R occurs.

[0332] Assuming bending is about a central neutral axis, Y max =t b / 2 S b=E*t b / (2*R) is.

[0333] In some embodiments, rolling diaphragm and / or bellows designs for high cycle life are based on geometries that keep the imposed bending stresses approximately at a magnitude less than the pressure-based loads (hoop and axial stresses). b =E*t b Based on / (2*R), R c In direct proportion to t b It is clear that minimizing Rc should not increase bending stresses. The minimum thickness for exemplary embodiments of rolling diaphragm and / or bellows materials or membranes is directly related to the minimum fiber diameter used in the elastomeric reinforcement. The finer the fibers used, the smaller the resulting Rc for a given stress level.

[0334] Another limiting component of the load on a rolling diaphragm and / or bellows is the hoop stress in the convolution (theoretically, it is the same magnitude as the longitudinal load while supported by the piston or cylinder). The governing equation for that load is:

[0335] S h =P d *R c / t b Therefore, R c t b If R is decreased in direct proportion to c A b If this ratio is reduced in a manner that reduces it to a ratio greater than R, then the parameters must be balanced. c For t bReducing the flexural load (V) requires the rolling diaphragm and / or bellows to support a greater stress due to pressure, but produces a reduced stress level due to bending. This can be advantageous because the pressure-based load is essentially constant, and therefore, because the bending load is cyclic, it is the bending load component that ultimately limits fatigue life.

[0336] To reduce bending stress, t b should ideally be at a minimum, and R c Ideally, R should be at its maximum value. E should also be at its minimum value. To reduce hoop stress, R c is ideally small, and t b is ideally large.

[0337] Therefore, the important parameters of the rolling diaphragm and / or bellows membrane material are:

[0338] E: Elastic modulus of the membrane material, t b : membrane thickness (and / or fiber diameter), S ut : Ultimate ten...

Claims

1. 1. A water vapor distillation apparatus comprising: A feed fluid inlet; 1. An evaporator-condenser apparatus comprising: a substantially cylindrical housing; a plurality of tubes in the housing, the feed fluid inlet fluidly connected to the evaporator-condenser via the plurality of tubes, the evaporator-condenser converting the feed fluid into vapor and converting the compressed vapor into a product fluid; An evaporator / condenser device comprising: a heat exchanger fluidly connected to the feed fluid inlet and the product fluid outlet, the heat exchanger comprising: An outer tube, At least one inner tube; A heat exchanger comprising: a regenerative blower fluidly connected to the evaporator-condenser, the regenerative blower compressing vapor and the compressed vapor flowing to the evaporative condenser, where the compressed vapor is converted into a product fluid; A steam distillation apparatus comprising: a control system for controlling the water vapor distillation apparatus; a Stirling engine electrically connected to the water vapor distillation apparatus, the Stirling engine at least partially powering the water vapor distillation apparatus; A steam distillation system comprising:

2. A control system for controlling the water vapor distillation apparatus is provided. a discharge controller for controlling the discharge valve; A raw material flow rate controller that controls the raw material flow rate valve; an emission level sensor connected to the emission controller and to the feed flow controller, the emission level sensor sending a signal related to the emission level to the emission controller and to the feed flow controller indicative of the emission level; Further comprising: The raw material flow controller drives the raw material flow valve based on at least a signal from the discharge level sensor; The discharge controller drives the discharge valve based on at least a signal from the discharge level sensor; The emission level and the feed flow level are maintained by using the emission level sensor signal as an input.

2. The water vapor distillation system according to claim 1 .

3. A control system for controlling the water vapor distillation apparatus includes: At least one controller; an idle state in which the at least one controller is not operating; an injection state in which the raw material valve is opened and the raw material fluid enters the water reservoir of the water vapor distillation apparatus; a heating state in which a heater in the water reservoir is operated at maximum output until the water in the water reservoir reaches a predetermined temperature; a heat exchanger peak condition in which the feed valve is opened to a predetermined duty cycle; a start pump state which drives the bearing feed pump at a predetermined speed and starts the discharge motor; an operating state in which the water vapor distillation apparatus produces product water; 3. The water vapor distillation system according to claim 1 or 2, further comprising:

4. The Stirling engine is At least one locking drive mechanism, a rocking beam having a rocker pivot; At least one cylinder; at least one piston housed within each cylinder, the piston being capable of substantially linear reciprocating movement within the respective cylinder; at least one linkage assembly having a proximal end and a distal end, the proximal end connected to the piston and the distal end connected to the rocking beam by an end pivot, such that linear motion of the piston is translated into rotational motion of the rocking beam; a locking drive mechanism comprising: a crankcase housing the rocking beam and housing a first portion of the coupling assembly; a crankshaft connected to the rocking beam by a connecting rod, the rotational motion of the rocking beam being transmitted to the crankshaft; a working space housing the at least one cylinder, the at least one piston, and a second portion of the coupling assembly; a seal for sealing the working space from the crankcase; 2. The water vapor distillation system according to claim 1, comprising:

5. 5. The water vapor distillation system of claim 1, wherein the seal is a rolling diaphragm.

6. The connection assembly includes: A piston rod, Link stick and Further comprising:

6. The water vapor distillation system according to claim 1, wherein the piston rod and the link rod are connected by a connecting means.

7. 7. The water vapor distillation system of claim 1, further comprising a lubricating fluid pump within the crankcase.

8. 8. The water vapor distillation system according to claim 1, wherein the heat exchanger is disposed around the housing of the evaporator / condenser.

9. 9. The steam distillation system according to claim 1, wherein the outer tube of the heat exchanger is a raw fluid flow path, and the at least one inner tube is a product fluid flow path.

10. 10. The water vapor distillation system according to claim 1, wherein the heat exchanger further comprises at least three inner tubes.

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