HK1188202A - Electrical purification apparatus - Google Patents

Description

Electric purification equipment

Cross Reference to Related Applications

The present application claims priority from U.S. provisional patent application serial No. 61/413021 entitled "CROSS-FLOW ELECTROCHEMICAL stability DEVICE AND METHODS OF manual actuation thermal method" filed on 12.2010 and U.S. provisional patent application serial No. 61/510157 entitled "module CROSS-FLOW ELECTROCHEMICAL DEVICES AND METHODS OF manual actuation thermal method" filed on 21.7.2011 in 35 u.s.c. $ 119(e), the entire disclosure OF each OF which is hereby incorporated herein by reference in its entirety for all purposes.

Technical Field

The present disclosure relates to systems and methods of water treatment, and methods of making systems or devices for treating water. More particularly, the present disclosure relates to systems and methods of water treatment using electrically powered purification devices and methods of manufacturing electrically powered purification devices for treating water.

Disclosure of Invention

One or more aspects of the present disclosure relate to a method of making a first cell stack for an electrical purification apparatus. Methods may include securing a first anion exchange membrane to a first cation exchange membrane at a first portion of a perimeter of the first anion exchange membrane and the first cation exchange membrane to form a first compartment having a first fluid flow path. The method may further include securing a second anion exchange membrane to the first cation exchange membrane at a second portion of the perimeter of the first cation exchange membrane and a first portion of the perimeter of the second anion exchange membrane to form a second compartment having a second fluid flow path that is different in direction from the first fluid flow path. Each of the first and second compartments may be constructed and arranged to provide fluid contact greater than 85% of the surface area of each of the first cation exchange membrane, the first anion exchange membrane, and the second cation exchange membrane.

Other aspects of the invention relate to methods of making a cell stack for use in an electrical purification apparatus. Methods may include forming a first compartment by securing a first cation exchange membrane to a first anion exchange membrane at a first portion of a perimeter of the first cation exchange membrane and the first anion exchange membrane to provide a first spacer assembly having a first spacer disposed between the first cation exchange membrane and the first anion exchange membrane. The method may further comprise forming a second compartment by securing a second anion exchange membrane to a second cation exchange membrane at a first portion of a perimeter of the second cation exchange membrane and the second anion exchange membrane to provide a second spacer assembly having a second spacer interposed between the second anion exchange membrane and the second cation exchange membrane. The method may further include forming a third compartment by securing the first spacer assembly to the second spacer assembly at a second portion of the perimeter of the first cation exchange membrane and at a portion of the perimeter of the second anion exchange membrane to provide a stack assembly having a spacer disposed between the first spacer assembly and the second spacer assembly. Each of the first and second compartments may be constructed and arranged to provide a fluid flow direction in a different direction than a fluid flow direction in the third compartment.

Still further aspects of the present disclosure may provide an electrical purification apparatus including a cell stack. The cell stack can include a first compartment including a first cation exchange membrane and a first anion exchange membrane. The first compartment may be constructed and arranged to provide direct fluid flow in a first direction between the first cation exchange membrane and the first anion exchange membrane. The cell stack may further include a second compartment including the first anion exchange membrane and the second cation exchange membrane to provide direct fluid flow in a second direction between the first anion exchange membrane and the second cation exchange membrane. Each of the first and second compartments is constructed and arranged to provide fluid contact greater than 85% of the surface area of the first cation exchange membrane, the first anion exchange membrane, and the second cation exchange membrane.

Other aspects of the invention relate to a cell stack for an electrical purification apparatus. The cell stack may comprise a plurality of alternating ion depleting and ion concentrating compartments. Each ion depleting compartment may have an inlet and an outlet providing a flow of diluting fluid in a first direction. Each ion concentrating compartment may have an inlet and an outlet providing a flow of concentrated fluid in a second direction different from the first direction. The cell stack may further include a blocking spacer disposed within the cell stack. The blocking spacer may be constructed and arranged to change a direction of at least one of a diluting fluid flow and a concentrating fluid flow through the cell stack.

Other aspects of the invention relate to electrically powered decontamination apparatus. The electro-kinetic purification device includes a cell stack that includes a plurality of alternating ion diluting compartments and ion concentrating compartments. Each ion diluting compartment may be constructed and arranged to provide fluid flow in a first direction. Each ion concentrating compartment may be constructed and arranged to provide fluid flow in a second direction different from the first direction. The electrokinetic purification device can include a first electrode adjacent to the anion exchange membrane at a first end of the cell stack. The electrokinetic purification device may further include a second electrode adjacent the cathode exchange membrane at the second end of the cell stack. The blocking spacer may be disposed within the cell stack and constructed and arranged to redirect at least one of a dilute fluid flow and a concentrated fluid flow through the electrical purification apparatus and prevent a direct current path between the first electrode and the second electrode.

In still other aspects of the present disclosure, methods of providing a source of potable water are provided. The method may include providing an electrically powered decontamination apparatus including a cell stack. The cell stack may comprise alternating ion diluting compartments and ion concentrating compartments. Each ion diluting compartment may be constructed and arranged to provide fluid flow in a first direction. Each ion concentrating compartment may be constructed and arranged to provide fluid flow in a second direction different from the first direction. Each of the ion concentrating compartments and the ion diluting compartments may be constructed and arranged to provide fluid contact of greater than 85% of the surface area of each of the alternating ion diluting compartments and ion depleting compartments. The method may further comprise fluidly connecting a seawater feed stream comprising about 35000 ppm total dissolved solids to an inlet of the electrically powered purification apparatus. The method may further comprise fluidly connecting an outlet of the electrically powered purification apparatus to a point of use.

Drawings

The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures is represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing.

In the drawings:

fig. 1 is a schematic illustration of a portion of an electrically powered decontamination apparatus in accordance with one or more embodiments of the present disclosure;

FIG. 2 is a schematic illustration of a portion of an electrically powered decontamination apparatus in accordance with one or more embodiments of the present disclosure;

FIG. 3 is a schematic illustration of a portion of an electrically powered decontamination apparatus in accordance with one or more embodiments of the present disclosure;

FIG. 4 is a schematic illustration of a portion of an electrically powered decontamination apparatus in accordance with one or more embodiments of the present disclosure;

figure 5 is a schematic illustration of a side view of a portion of an electrodeionization device comprising a stack of membrane cells disposed in a housing, according to one or more embodiments of the disclosure;

figure 6 is a schematic illustration of a side view of a portion of an electrodeionization device comprising a stack of membrane cells disposed in a housing, according to one or more embodiments of the disclosure;

figure 7 is a schematic illustration of a side view of a portion of an electrodeionization device comprising a stack of membrane cells disposed in a housing, according to one or more embodiments of the disclosure;

fig. 8 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 9 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 10 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 11 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 12 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 13 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 14 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 15 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 16 is a schematic illustration of a method of securing a stack of membrane cells in a housing according to one or more embodiments of the present disclosure;

fig. 17 is a schematic illustration of a multi-pass electrical purification apparatus according to one or more embodiments of the present disclosure;

fig. 18 is a schematic illustration of a blocking spacer according to one or more embodiments of the present disclosure;

FIG. 19 is a schematic illustration of a spacer assembly and a blocking spacer disposed therebetween according to one or more embodiments of the present disclosure;

fig. 20 is a schematic illustration of a portion of an electrical purification apparatus including a cell stack disposed within a housing, according to one or more embodiments of the present disclosure;

fig. 21 is a schematic illustration of a blocking spacer according to one or more embodiments of the present disclosure;

fig. 22 is a schematic illustration of a portion of an electrical purification apparatus of a cell stack disposed within a housing according to one or more embodiments of the present disclosure;

23A and 23B are schematic illustrations of a portion of an electrical purification apparatus including a cell stack disposed within a housing, according to one or more embodiments of the present disclosure;

fig. 24A and 24B are schematic illustrations of a portion of an electrical purification apparatus including a first modular unit, a second modular unit, and a blocking spacer disposed therebetween, in accordance with one or more embodiments of the present disclosure;

fig. 25 is a schematic illustration of a blocking spacer according to one or more embodiments of the present disclosure;

FIG. 26 is a schematic illustration of a spacer assembly according to one or more embodiments of the present disclosure;

fig. 27 is a schematic illustration of a cell stack according to one or more embodiments of the present disclosure;

fig. 28 is a schematic illustration of a cell stack according to one or more embodiments of the present disclosure;

fig. 29 is a schematic illustration of a cell stack according to one or more embodiments of the present disclosure;

fig. 30 is a schematic illustration of a spacer according to one or more embodiments of the present disclosure;

fig. 31 is a schematic illustration of a sectioned and exploded view of a cell stack of spacers and membranes according to one or more embodiments of the present disclosure;

figure 32 is a schematic illustration of a cross-sectional view and an enlarged view of a partially assembled cell stack according to one or more embodiments of the present disclosure;

fig. 33 is a schematic illustration of a portion of an assembled stack according to one or more embodiments of the present disclosure;

fig. 34 is a schematic illustration of an overmolded spacer according to one or more embodiments of the present disclosure;

fig. 35 is a schematic illustration of a cross-sectional view of a cell stack according to one or more embodiments of the present disclosure;

fig. 36 is a schematic illustration of a cross-sectional view of a cell stack according to one or more embodiments of the present disclosure;

fig. 37 is a schematic illustration of a top view of a spacer according to one or more embodiments of the present disclosure;

fig. 38A and 38B are schematic illustrations of details of a spacer according to one or more embodiments of the present disclosure. FIG. 38B is a cross-section of FIG. 38A taken along line B-B.

Fig. 39 is a schematic illustration of a stack of spacers and membranes according to one or more embodiments of the present disclosure;

fig. 40 is a schematic illustration of a stack of spacers and membranes according to one or more embodiments of the present disclosure;

fig. 41 is a schematic illustration of a stack of spacers and membranes according to one or more embodiments of the present disclosure;

fig. 42 is a schematic illustration of a stack of spacers and membranes according to one or more embodiments of the present disclosure;

fig. 43 is a schematic illustration of a stack of spacers and membranes according to one or more embodiments of the present disclosure; and

fig. 44 is a schematic illustration of a stack of spacers and membranes according to one or more embodiments of the present disclosure.

At least some of the figures may depict the membrane, the spacer, the cell stack, and the housing in a particular configuration and geometry. However, the present disclosure is not limited to these specific configurations and geometries. For example, the housing may have any suitable geometry such that one or more membrane cell stacks or modular units may be secured therein. For example, the housing may be cylindrical, polygonal, square, or rectangular. With respect to membrane cell stacks and modular units, any suitable geometry may be acceptable so long as the cell stack or modular unit can be secured to the housing. For example, the membrane or spacer may be rectangular in shape. In some embodiments, no housing may be required. The geometry of the membranes and spacers may have any suitable geometry that allows the membranes and spacers to be secured within the cell stack. In some embodiments, a particular number of corners or vertices on the cell stack may be desirable. For example, three or more corners or vertices may be required to secure the cell stack to the housing. In certain embodiments, the geometry of any of the housing, the cell stack, the membrane, and the spacer may be selected to accommodate operating parameters of the electrical purification apparatus. For example, the spacer may be asymmetric to accommodate flow rate differences between the dilute and concentrate flows.

Detailed Description

Devices for purifying fluids using electric fields are commonly used to treat water and other liquids containing dissolved daughter species. Two devices that treat water in this manner are electrodeionization devices and electrodialysis devices.

Electrodeionization (EDI) is a process that uses an electroactive media and an electrical potential to affect ion transport to remove or at least reduce one or more ionized or ionizable species from water. Electroactive media are commonly used to alternately collect and discharge ionic and/or ionizable species, and in some cases facilitate ion transport by ionic or electron substitution mechanisms, which may be continuous. EDI devices can include electrochemically active media having a permanent or temporary charge, and can operate in batch, intermittent, continuous, and/or even reversed polarity modes. The EDI device may be operable to facilitate one or more electrochemical reactions specifically designed to achieve or enhance performance. Furthermore, such electrochemical devices may comprise electroactive membranes, such as semipermeable or permselective ion exchange membranes or bipolar membranes. Continuous Electrodeionization (CEDI) devices are EDI devices known to those skilled in the art that operate in a manner that enables continuous water purification while continuously replenishing ion exchange material. CEDI technology can include processes such as continuous deionization, packed cell electrodialysis, or electrodialysis (electrodialysis). Under controlled voltage and salinity conditions, in CEDI systems, water molecules can be split to produce hydrogen or hydronium ions or species and hydroxyl or hydroxyl ions or species, which can regenerate the ion exchange media in the device and thus facilitate the release of trapped species therefrom. In this way, the water stream to be treated can be continuously purified without the need for chemical replenishment of the ion exchange resin.

Electrodialysis (ED) devices operate on a similar principle to CEDI, except that ED devices generally do not contain an electroactive medium between membranes. Due to the lack of electroactive media, the operation of ED can be hindered by low salinity feed water due to increased electrical resistance. Also, because the operation of ED on high salinity water supplies can result in increased current consumption, ED equipment has been most effectively used so far for medium salinity water sources. In ED-based systems, the cracking of water is inefficient due to the absence of electroactive media and operation in this manner is generally avoided.

In CEDI and ED devices, a plurality of adjacent cells or compartments are typically separated by a selectively permeable membrane that allows passage of positively or negatively charged species (but typically not both). The dilution or depletion compartments are usually provided at intervals with concentrating or pooling compartments in such devices. As the water flows through the depleting compartments, ionic and other charged species are typically pulled into the concentrating compartments under the influence of an electric field (e.g., a DC field). Positively charged species are drawn toward the cathode at one end of the stack, typically at a plurality of depleting and concentrating compartments, and negatively charged species are similarly drawn toward the anode of such devices, typically at the opposite end of the cell stack of compartments. The electrodes are typically housed within electrolyte compartments, which are typically partially isolated from fluid communication with the depleting and/or concentrating compartments. Once within the concentrating compartment, the charged species are typically captured by a barrier of a selectively permeable membrane that at least partially defines the concentrating compartment. For example, anions are generally prevented from further migration out of the concentrating compartment towards the cathode by a cation selective membrane. Once captured within the concentration compartment, the captured charged species can be removed into the concentration stream.

In CEDI and ED devices, a DC electric field is typically applied to the cell by a voltage and current source applied to electrodes (anode or positive, and cathode or negative). The voltage and current sources (collectively referred to as "power sources") can themselves be powered by various means such as an AC power source or a power source derived from, for example, solar, wind or wave energy. An electrochemical half-cell reaction occurs at the electrode/liquid interface, which initiates and/or facilitates the transfer of ions across the membrane and compartment. The specific electrochemical reactions occurring at the electrodes/interfaces can be controlled to some extent by the salt concentration within the dedicated compartment housing the electrode assembly. For example, a feed to a high sodium chloride anolyte compartment will tend to produce chlorine and hydrogen ions, while such a feed to a catholyte compartment will tend to produce hydrogen and hydroxide ions. In general, the hydrogen ions produced at the anode compartment will be associated with free anions, such as chloride ions, thereby maintaining electrical neutrality and producing a hydrochloric acid solution, and similarly the hydroxide ions produced at the cathode compartment will be associated with free cations, such as sodium, thereby maintaining electrical neutrality and producing a sodium hydroxide solution. The reaction products of the electrode compartment, such as the generated chlorine and sodium hydroxide, can be used in the process for disinfection purposes, membrane cleaning and decontamination purposes, and for pH adjustment purposes, as desired.

Plate-frame and spiral wound designs have been used in a variety of electrochemical deionization devices including, but not limited to, Electrodialysis (ED) and Electrodeionization (EDI) devices. Commercially available ED devices are typically of a plate-frame design, while EDI devices can be used for both plate and frame and spiral configurations.

The present invention relates to devices that can electrically purify fluids that may be contained within a housing, and methods of making and using the same. The liquid or other fluid to be purified enters the purification apparatus or device and is treated under the influence of an electric field to produce an ion depleted liquid. Nuclides from the incoming liquid are collected to produce an ion-concentrated liquid. Various techniques may be used to assemble the components of an electrokinetic purification apparatus, which may also be referred to as an electrochemical separation system or electrochemical separation device, in order to achieve optimal operation of the apparatus.

In some embodiments of the present disclosure, methods are provided for affixing or bonding ion exchange membranes and optionally spacers in order to manufacture membrane cell stacks for electrokinetic purification devices. The method may be provided to immobilize a plurality of anion exchange membranes and cation exchange membranes used in an electrokinetic purification apparatus such as a cross-flow Electrodialysis (ED) device.

In certain embodiments of the present disclosure, a method of preparing a first cell stack for an electrical purification apparatus is provided. The method may include affixing the first ion exchange membrane to the second ion exchange membrane. A spacer may be disposed between the first ion exchange membrane and the second ion exchange membrane to form a spacer assembly. When used in an electrical purification apparatus, such a spacer assembly defines a first compartment that can allow fluid flow. A plurality of ion exchange membranes may be secured to one another so as to provide a series of compartments. In certain embodiments, multiple spacer assemblies may be constructed and the spacer assemblies may be secured to one another. Spacers may be placed between each spacer assembly. In this way, a series of compartments for an electrically powered purification apparatus are configured to allow fluid flow in one or more directions within each compartment.

A partition, which may be positioned within the compartment, may provide structure to and define the compartment, and may help direct fluid flow through the compartment in certain examples. The spacer may be made of a polymeric material or other material that achieves the desired structure and fluid flow within the compartment. In certain embodiments, the spacer may be constructed and arranged to redirect or redistribute fluid flow within the compartment. In some examples the spacer may comprise a mesh or screen material to provide structure and allow the desired fluid flow through the compartment.

According to one or more embodiments, the efficiency of an electrochemical separation system may be improved. Current loss is one possible source of inefficiency. In some embodiments, such as those involving cross-current designs, the possibility of current leakage may be addressed. Current efficiency may be defined as the percentage of current that is effective to move ions from a dilute stream into a concentrated stream. Various sources of current inefficiency may exist in electrochemical separation systems or electrical purification devices. One potential source of inefficiency may involve current bypassing cell pairs (pairs of adjacent concentrating and diluting compartments) by flowing through diluting and concentrating inlet and outlet manifolds. The open inlet and outlet manifolds may be in direct fluid communication with the flow compartments and may reduce the pressure drop within each flow path. Part of the current from one electrode to the other can bypass the stack of cell pairs by flowing through the open area. Such bypass currents reduce current efficiency and increase energy consumption. Another source of potential inefficiency may involve ions entering the dilute stream from the concentrate stream due to imperfect permselectivity of the ion exchange membrane. In some embodiments, techniques related to sealing and potting of membranes and screens within devices may help reduce current leakage.

In one or more embodiments, a bypass path through the stack may be manipulated to facilitate current flow along a direct path through the cell stack in order to improve current efficiency. In some embodiments, the electrochemical separation device or the electrical purification apparatus may be constructed and arranged such that the one or more bypass paths are more tortuous than the direct path through the cell stack. In at least certain embodiments, the electrochemical separation device or the electrically powered purification apparatus may be constructed and arranged such that the one or more bypass paths exhibit a higher electrical resistance than the direct path through the cell stack. In some embodiments involving modular systems, each modular unit may be configured to facilitate current efficiency. The modular units may be constructed and arranged to provide a current bypass path that will contribute to current efficiency. In non-limiting embodiments, the modular unit may include a manifold system and/or a flow distribution system configured to facilitate current efficiency. In at least some embodiments, a frame surrounding a cell stack in an electrochemical separation unit can be constructed and arranged to provide a predetermined current bypass path. In some embodiments, facilitating a multi-pass flow configuration in an electrochemical separation device can help reduce current leakage. In at least some non-limiting embodiments, barrier films or spacers may be inserted between the modular units to direct the dilute and/or concentrate streams into a multi-pass flow configuration to improve current efficiency. In some embodiments, a current efficiency of at least about 60% may be achieved. In other embodiments, a current efficiency of at least about 70% may be achieved. In still other embodiments, a current efficiency of at least about 80% may be achieved. In at least some embodiments, a current efficiency of at least about 85% can be achieved.

The spacer may be constructed and arranged to redirect at least one of fluid flow and current flow in order to improve current efficiency. The spacer may also be constructed and arranged to create multiple fluid flow stages in the electrical purification apparatus. The spacer may include a solid portion to redirect fluid flow in a particular direction. The solid portion may also redirect current flow in a particular direction and prevent a direct path between the anode and cathode within the electrical purification apparatus. A spacer including a solid portion may be referred to as a blocking spacer. The blocking spacer may be disposed within the cell stack or may be disposed between the first cell stack or the first modular unit and the second cell stack or the second modular unit.

A plurality of ion exchange membranes, which in some embodiments are fixed to each other, may alternate between cation exchange membranes and anion exchange membranes so as to provide a series of ion diluting compartments and ion concentrating compartments.

The geometry of the membrane may be any suitable geometry such that the membrane may be secured within the cell stack. In some embodiments, it may be desirable to have a certain number of corners or vertices on the cell stack in order to properly secure the cell stack within the housing. In certain embodiments, a particular membrane may have a different geometric configuration than other membranes within the cell stack. The geometry of the membrane may be selected to facilitate at least one of: securing the membranes to each other, securing the spacers within the cell stack, securing the membranes within the modular units, securing the membranes within the support structure, securing a set of membranes, such as the cell stack, to the housing, and securing the modular units into the housing.

The membrane, spacer and spacer assembly may be secured at a portion of a perimeter or edge of the membrane, spacer or spacer assembly. A portion of the perimeter may be a continuous or discontinuous length of film, spacer, or spacer assembly. The portion of the perimeter selected to secure the membrane, spacer or spacer assembly may provide a boundary or demarcation to direct fluid flow in a predetermined direction.

In certain embodiments, a method of making a battery stack may include securing a first anion exchange membrane to a first cation exchange membrane at a first portion of a perimeter of the first anion exchange membrane and the first cation exchange membrane to form a first compartment having a first fluid flow path. The method may further include securing a second anion exchange membrane to the first cation exchange membrane at a second portion of the perimeter of the first cation exchange membrane and a first portion of the perimeter of the second anion exchange membrane to form a second compartment having a second fluid flow path that is different in direction from the first fluid flow path.

The first fluid flow path and the second fluid flow path may be selected and provided by means of the portions of the periphery of the ion exchange membrane that are fixed to each other. Using the first fluid flow path as the direction extending along the 0 ° axis, the second fluid flow path may extend in any angular direction greater than zero degrees and less than 360 °. In certain embodiments of the present disclosure, the second fluid flow path may extend at a 90 ° angle or perpendicularly with respect to the first fluid flow path. In other embodiments, the second fluid flow path may extend at a 180 ° angle relative to the first fluid flow path. In another embodiment, the first fluid flow path may extend in the 0 ° direction. The second fluid flow path may extend at 60 ° and the third fluid flow path may extend at 120 °. The fourth fluid flow path may extend at 0 °.

If additional ion exchange membranes are secured to the cell stack to provide additional compartments, the fluid flow paths within these additional compartments may be the same or different from the first and second fluid flow paths. In certain embodiments, the fluid flow path within each compartment alternates between a first fluid flow path and a second fluid flow path. For example, the first fluid flow path within the first compartment may extend in the 0 ° direction. The second fluid flow path in the second compartment may extend in the 90 ° direction and the third fluid flow path in the third compartment may extend in the 0 ° direction. In certain examples, a first fluid flow path extending in a first direction and a second fluid flow path extending in a second direction may be referred to as cross-flow electrical purification.

In other embodiments, the fluid flow path within each compartment alternates sequentially between the first fluid flow path, the second fluid flow path, and the third fluid flow path. For example, the first fluid flow path within the first compartment may extend in the 0 ° direction. The second fluid flow path in the second compartment may extend at 30 ° and the third fluid flow path in the third compartment may extend at 90 °. The fourth fluid flow path within the fourth compartment may extend at 0 °. In another embodiment, the first fluid flow path within the first compartment may extend in the 0 ° direction. The second fluid flow path in the second compartment may extend at 60 ° and the third fluid flow path in the third compartment may extend at 120 °. The fourth fluid flow path within the fourth compartment may extend at 0 °.

In certain embodiments of the present disclosure, the flow within the compartment may be regulated, redistributed or redirected to provide greater contact of the fluid with the membrane surface within the compartment. The compartment may be constructed and arranged to redistribute fluid flow within the compartment. The compartment may have an obstruction, bump, ridge, flange, or baffle that may provide a structure that redistributes the flow through the compartment, as will be discussed further below. In certain embodiments, the obstructions, bumps, ridges, flanges, or baffles may be referred to as flow redistributors.

Each compartment in a cell stack for an electrical purification apparatus may be constructed and arranged to provide a predetermined percentage of surface area or membrane utilization for fluid contact. It has been found that greater membrane utilization provides greater efficiency in the operation of an electrokinetic purification apparatus. Advantages of achieving greater membrane utilization may include lower energy consumption, smaller equipment footprint, fewer passes through the equipment, and higher quality product water. In certain embodiments, a membrane utilization greater than 65% can be achieved. In other embodiments, a membrane utilization greater than 75% may be achieved. In certain other embodiments, the membrane utilization that can be achieved can be greater than 85%. The membrane utilization rate may depend at least in part on the method used to secure each membrane to each other and the design of the spacer. In order to obtain a predetermined membrane utilization, appropriate fastening techniques and components may be selected in order to achieve a reliable and safe seal that allows for optimal operation of the electrical purification apparatus without encountering leakage problems within the apparatus, while maintaining a large surface area of the membrane that may be used in the process.

The seal may be achieved by any suitable means to ensure a fit between the membranes to provide the desired fluid flow path through the compartment defined by the membranes. For example, sealing may be accomplished by adhesives, thermal bonding, such as by laser or ultrasonic welding, or by mating or interlocking (e.g., using male and female features on adjacent films and/or spacers). In certain examples, to construct a membrane cell stack, a plurality of spacer assemblies are constructed and bonded or secured together by an adhesive applied at a portion of the periphery of the spacer assemblies. A spacer is disposed between each of the spacer assemblies secured together. In certain examples, the spacer assemblies may be secured to each other at a portion of the perimeter of each spacer assembly so as to provide a plurality of compartments having at least two fluid flow paths. For example, the spacer assembly may be secured to each other so as to provide a first compartment having a fluid flow path in a first direction and a second compartment having a fluid flow path in a second direction. Instead of an adhesive, thermal bonding or mechanical interlocking features may be used to provide the compartments.

In some embodiments of the present disclosure, a method for making a cell stack for an electrical purification apparatus includes forming a compartment. A first spacer assembly having a first spacer disposed between ion exchange membranes may be provided by securing the ion exchange membranes to one another to form a first compartment. For example, a first cation exchange membrane may be secured to a first anion exchange membrane at a first portion of the perimeter of the first cation exchange membrane and the first anion exchange membrane to provide a first spacer assembly having a first spacer disposed between the first cation exchange membrane and the first anion exchange membrane.

A second compartment may be formed by securing ion exchange membranes to one another to provide a second spacer assembly having a second spacer disposed between the ion exchange membranes. For example, a second anion exchange membrane may be secured to a second cation exchange membrane at a first portion of the perimeter of the second cation exchange membrane and the first anion exchange membrane to provide a second spacer assembly having a second spacer disposed between the second anion exchange membrane and the second cation exchange membrane.

A third compartment may be formed between the first compartment and the second compartment by securing the first spacer assembly to the second spacer assembly and placing a spacer therebetween. For example, a first spacer assembly may be secured to a second spacer assembly at a second portion of the perimeter of a first cation exchange membrane and at a portion of the perimeter of a second anion exchange membrane to provide a stack assembly having a spacer interposed between the first spacer assembly and the second spacer assembly.

Each of the first and second compartments may be constructed and arranged to provide a fluid flow direction that is different from the fluid flow direction in the third compartment. For example, the fluid flow within the third compartment may extend in the 0 ° direction. The fluid flow within the first compartment may extend at 30 °, and the fluid flow within the second compartment may extend at the same angle (30 °) as the first compartment or at another angle (e.g. 120 °). In another example, the fluid flow path within the first compartment may extend in the 0 ° direction. The fluid flow path within the third compartment may extend at 60 ° and the fluid flow path within the second compartment may extend at 120 °. The fluid flow path within the fourth compartment may extend at 0 °.

The method may further include securing the assembled cell stack within a housing.

In accordance with one or more embodiments, the electrochemical separation system or the electrokinetic purification apparatus can be modular. Each modular unit may generally serve as a sub-block of the overall electrochemical separation system. The modular unit may include any desired number of battery pairs. In some embodiments, the number of battery pairs per modular unit may depend on the total number of battery pairs and passageways in the separation device. It may also depend on the number of cell pairs that can be thermally bonded and potted within the frame with an acceptable failure rate when tested for cross-leakage or other performance criteria. This number can be based on statistical analysis of the manufacturing process and can increase as process control improves. In some non-limiting embodiments, the modular unit may include about 50 battery pairs. The modular units may be individually assembled and quality control tested, for example, for leaks, separation performance, and pressure drop, before being incorporated into a larger system. In some embodiments, the cell stacks may be mounted within the frame as modular units that can be independently tested. A plurality of modular units can then be assembled together to provide a desired total number of battery pairs in an electrochemical separation device. In some embodiments, the method of assembling may generally include placing a first modular unit on a second modular unit, placing a third modular unit on the first and second modular units, and repeatedly obtaining a desired number of the plurality of modular units. In some embodiments, the assembly or individual modular units may be inserted into a pressure vessel for operation. A multi-pass flow configuration may be achieved with barrier films and/or spacers placed between or within modular units. The modular approach may improve manufacturability in terms of time and cost savings. Modularity may also facilitate system maintenance by allowing individual modular units to be diagnosed, isolated, removed, and replaced. Each modular unit may include a manifold and a flow distribution system to facilitate the electrochemical separation process. The individual modular units may be in fluid communication with each other, as well as with a central manifold and other systems associated with the overall electrochemical separation process.

The cell stack may be secured within a frame or support structure that includes an inlet manifold and an outlet manifold to provide a modular unit. This modular unit may then be secured within the housing. The modular unit may further comprise a bracket assembly or corner support securing the modular unit to the enclosure. The second modular unit may be secured within the housing. One or more additional modular units may also be secured within the housing. In certain embodiments of the present disclosure, a blocking spacer may be positioned between the first modular unit and the second modular unit.

A flow redistributor may be present within one or more compartments of the cell stack. In assembling the cell stack, the first portion of the perimeter of the ion exchange membrane within the cell stack may be constructed and arranged to interlock with the first portion of the perimeter of an adjacent ion exchange membrane. In certain examples, a first portion of a perimeter of a first spacer within a cell stack can be constructed and arranged to interlock with a first portion of a perimeter of an adjacent spacer.

In some embodiments of the present disclosure, an electrically powered decontamination apparatus is provided that includes a cell stack. The electrically powered purification apparatus may include a first compartment including ion exchange membranes and may be constructed and arranged to provide direct fluid flow in a first direction between the ion exchange membranes. The electrically powered purification apparatus may also include a second compartment comprising an ion exchange membrane and may be constructed and arranged to provide direct fluid flow in a second direction. Each of the first and second compartments may be constructed and arranged to provide a predetermined percentage of surface area or membrane utilization for fluid contact. In certain embodiments, a membrane utilization greater than 65% can be achieved. In other embodiments, a membrane utilization greater than 75% may be achieved. In certain other embodiments, the membrane utilization that can be achieved can be greater than 85%. The membrane utilization rate may depend at least in part on the method used to secure each membrane to each other and the design of the spacer. In order to obtain a predetermined membrane utilization, appropriate fastening techniques and components may be selected in order to achieve a reliable and safe seal that allows for optimal operation of the electrical purification apparatus without encountering leakage problems within the apparatus, while maintaining a large surface area of the membrane that may be used in the process.

For example, an electrical purification apparatus may be provided that includes a battery stack. The electrokinetic purification apparatus may include a first compartment comprising a first cation exchange membrane and a first anion exchange membrane constructed and arranged to provide direct fluid flow in a first direction between the first cation exchange membrane and the first anion exchange membrane. The apparatus may further comprise a second compartment comprising the first anion exchange membrane and the second cation exchange membrane to provide direct fluid flow in a second direction between the first anion exchange membrane and the second cation exchange membrane. Each of the first and second compartments may be constructed and arranged to provide a predetermined membrane utilization, for example, fluid contact of greater than 85% of the surface area of the first cation exchange membrane, the first anion exchange membrane, and the second cation exchange membrane. At least one of the first compartment and the second compartment may include a spacer, which may be a blocking spacer.

Direct fluid flow in the first and second directions may be selected and provided by the configuration and arrangement of the compartments. Using the first fluid flow direction as the direction extending along the 0 ° axis, the second fluid flow direction may extend at any angle greater than zero degrees and less than 360 °. In certain embodiments of the present disclosure, the second fluid flow direction may be at a 90 ° angle or perpendicular relative to the first fluid flow direction. In other embodiments, the second fluid flow direction may be at an angle of 80 ° relative to the first fluid flow direction. If additional ion exchange membranes are secured to the cell stack to provide additional compartments, the direction of fluid flow within these additional compartments may be the same or different than the first and second fluid flow directions. In certain embodiments, the direction of fluid flow within each compartment alternates between a first fluid flow direction and a second fluid flow direction. For example, the first fluid flow direction may extend in the 0 ° direction. The second fluid flow direction may extend at an angle of 90 ° and the third fluid flow direction within the third compartment may extend in a direction of 0 °.

The electrical purification apparatus including the cell stack may further include a housing enclosing the cell stack, and at least a portion of a perimeter of the cell stack is secured to the housing. A frame may be disposed between the housing and the cell stack to provide a first modular unit within the housing. A flow redistributor may be present within one or more compartments of the cell stack. At least one compartment may be constructed and arranged to provide flow reversal within the compartment.

In some embodiments of the present disclosure, a battery cell stack for an electrical purification apparatus is provided. The cell stack may provide a plurality of alternating ion depleting and ion concentrating compartments. Each ion depleting compartment may have an inlet and an outlet providing a flow of diluting fluid in a first direction. Each ion concentrating compartment may have an inlet and an outlet providing a concentrated fluid flow in a second direction different from the first direction. The spacer may be placed in the cell stack. The partition may provide structure to and define the compartment, and may help direct fluid flow through the compartment in certain examples. The spacer may be a blocking spacer that may be constructed and arranged to redirect at least one of fluid flow and electrical current through the cell stack. As discussed, the blocking spacer may reduce or prevent current inefficiencies in the electrical purification apparatus.

In some embodiments of the present disclosure, an electrically powered decontamination apparatus is provided. The apparatus may comprise a cell stack comprising alternating ion diluting compartments and ion concentrating compartments. Each ion diluting compartment may be constructed and arranged to provide fluid flow in a first direction. Each ion concentrating compartment may be constructed and arranged to provide fluid flow in a second direction different from the first direction. The electrically powered purification apparatus may further include a first electrode adjacent the first ion exchange membrane at a first end of the cell stack and a second electrode adjacent the second ion exchange membrane at a second end of the cell stack. Each of the first ion exchange membrane and the second ion exchange membrane may be an anion exchange membrane or a cation exchange membrane. For example, the first ion exchange membrane may be an anion exchange membrane and the second ion exchange membrane may be a cation exchange membrane. The apparatus may further include a blocking spacer disposed within the cell stack and constructed and arranged to redirect at least one of a dilute fluid flow and a concentrated fluid flow through the electrical purification apparatus and prevent a direct current path between the first electrode and the second electrode. As discussed above, the blocking spacer may be constructed and arranged to reduce current inefficiencies in the electrical purification apparatus.

The cell stack of the electrical purification apparatus may be enclosed within a housing and at least a portion of a perimeter of the cell stack is secured to the housing. A frame may be disposed between the housing and the cell stack to provide a first modular unit within the housing. The second modular unit may also be secured within the housing. A blocking spacer may also be placed between the first modular unit and the second modular unit. A flow redistributor may be present within one or more compartments of the cell stack. At least one compartment may be constructed and arranged to provide flow reversal within the compartment. A bracket assembly may be disposed between the frame and the enclosure to provide support to the modular unit and to secure the modular unit within the enclosure.

In certain embodiments of the present disclosure, a portion of the perimeter of the ion exchange membranes or spacers in the cell stack may be treated or coated with a material so as to provide an enhanced securing bond with a securing material (e.g., a binder) and components of the cell stack. The sealing strips may be provided on the spacer, the membrane, or both so as to provide a continuous surface on which an adhesive may be applied to join ion exchange membranes such as anion and cation exchange membranes. The sealing strip may also provide support for the perimeter of the membrane. The seal may prevent or mitigate wetting or wicking of the adhesive, thereby allowing less adhesive to be used to secure the spacer and membrane together. The weatherstrip may also help to produce greater film utilization based on less adhesive used. In some examples, the sealing strip may be applied to the spacer by injection molding, compression molding, coating, or the like.

FIG. 1 shows a spacer assembly 10 including a cation exchange membrane 100, a spacer 104, and an anion exchange membrane 102. Spacers 104, which may be screen spacers, may allow for the application of adhesive 106. The film may be sealed along the two opposing edges by an adhesive or by a thermal bonding technique such as laser, vibration or ultrasonic welding. A variety of adhesives can be used for the side seams of the film, including epoxies and urethanes with aliphatic, cycloaliphatic, and aromatic amine curing agents, as will be described in more detail below. When adhesive is being applied to the adhesive lines of the film battery, it may be beneficial if the adhesive mainly remains on the predetermined adhesive lines. If the tack is too low, the adhesive may detach or drip from the glue line. If the adhesive is too viscous, spreading the adhesive becomes difficult.

If the spacer is a screen, it may be encapsulated in an adhesive that also bonds the two adjacent films.

FIG. 2 shows a spacer assembly 20 comprising a cation exchange membrane 200, a spacer 204, and an anion exchange membrane 202. The spacer 204 separates the cation exchange membrane 200 and the anion exchange membrane 202 and may define flow compartments and enhance mixing and mass transfer of the liquid stream as it flows from the inlet side 208 to the outlet side 210.

Fig. 3 shows first spacer assembly 30 and second spacer assembly 32 separated by spacer 304. The two components are bonded together by adhesive 306 applied along two parallel edges perpendicular to the edges that have been sealed within the components. The spacer 304, which is sandwiched between the two components, defines a flow channel for the second flow, which is perpendicular in direction to the flow through the two components, as indicated by the arrows.

The final membrane cell stack when compressed is shown in figure 4. As shown, the first spacer assembly 40 and the second spacer assembly 42 are secured to one another with the spacer 404 disposed therebetween. The flow path through each spacer assembly 40 and 42 may travel in a first direction, while the flow path through the compartment defined between the two spacer assemblies may travel in a second direction, as indicated by the arrows in FIG. 4.

The fluid flow in the first direction may be a dilute flow and the fluid flow in the second direction may be a concentrate flow. In certain embodiments, fluid flow in a first direction may be converted to a concentrated flow and fluid flow in a second direction may be converted to a dilute flow using polarity inversion (where the applied electric field is reversed thereby reversing the flow function).

A plurality of spacer assemblies separated by spacers may be secured together to form a cell-to-cell stack or a membrane cell stack.

The electrically powered purification apparatus of the present disclosure may further include a housing enclosing the cell stack. At least a portion of the perimeter of the cell stack may be secured to the housing. A frame or support structure may be positioned between the housing and the cell stack to provide additional support to the cell stack. The frame may also include inlet and outlet manifolds that allow liquid to flow into and out of the cell stack. The frame and the cell stack together may provide an electrically powered purification apparatus modular unit. The electrical purification apparatus may further comprise a second modular unit secured within the housing. A spacer, such as a blocking spacer, may be placed between the first modular unit and the second modular unit. The first electrode may be disposed at an end of the first modular unit opposite an end in communication with the second modular unit. The second electrode may be disposed at an end of the second modular unit opposite the end in communication with the first modular unit.

A bracket assembly may be disposed between the frame and the housing of the first modular unit, the second modular unit, or both. The bracket assembly may provide support for the modular unit and provide secure attachment to the enclosure.

In one embodiment of the present disclosure, an electrokinetic purification apparatus may be assembled by positioning a membrane cell stack within a housing or container. An end plate may be provided at each end of the cell stack. An adhesive may be applied to seal at least a portion of the perimeter of the cell stack to the inner wall of the housing.

Fig. 5 shows one embodiment of a cell stack 516 enclosed by a housing 518. The end plate 512 is drawn together with tie bars 514. The tie rod 514 is isolated from fluid flow by a non-metallic sleeve. If the end plates 512 are metallic, a non-metallic end block 520 may be inserted between the cell stack 516 and the end plates 512 at each end. End block 520 supports the electrodes and isolates the liquid flow from the end plates. The tie rod sleeve ends are sealed to the end block 520 by O-rings. Alternatively, the end plate 520 may be non-metallic and thus a separate end block may not be necessary. As shown in fig. 5, end plate 520 may be attached by means of bolts or threaded rods 522 and nuts 524. As shown in fig. 6, end plate 620 may be attached by means of a flange 649. As shown in FIG. 7, the end plates 720 may be attached by means of clips 728, e.g., Victaulic type clips.

In some embodiments of the present disclosure, the tie bar may be located outside the housing. In some other embodiments of the present disclosure, the end plates may be secured within the housing by segmented or snap rings inserted into grooves at the ends of the housing. The end plate may also be bonded to the housing by an adhesive.

The metal end plate may be manufactured by, for example, machining or casting. The non-metallic end block or end plate can be manufactured by machining a plastic block or by injection molding, for example.

Once the stack is placed within the housing and the end block/end plate is secured to the housing, an adhesive may be applied to seal the stack to the housing and isolate the inlet and outlet manifolds for the two streams from each other. The housing is first oriented so that the longitudinal axis is horizontal.

As discussed in further detail below, the adhesive properties used to secure the membrane stacks within the housing may be different than the adhesive properties used to secure the membranes to each other to form the cell stacks. In order to secure the stack of membranes within the housing, the adhesive tack must be low. Acceptable tack can be obtained by adding a reactive diluent to the mixed binder. The primary function of the diluent is to reduce its viscosity to make it easier to complex, or to improve application characteristics. Lower viscosity is also important in achieving a suitable adhesive because it allows more penetration into the porous matrix and allows wetting of the non-porous surface. The diluent may be diglycidyl ether, glycidyl phenyl glycidyl ether, or the like.

The membrane cell flow compartment may be about 0.33 mm to 0.46 mm thick, and in certain examples, the can may be void-free. The can elastomer (adhesive) used to secure the cell stack to the housing should be more rigid than the side seams used to secure the membranes to each other; this may be because the can must have sufficient mechanical strength to withstand the weight of the membrane stack. In certain embodiments, it may be desirable for the canister not to deform under the feed flow pressure.

The housing is first oriented so that the longitudinal axis is horizontal. Figure 8 illustrates one method of applying the adhesive 806 to secure the cell stack 816 within the housing 818. Housing 818 may be rotated so that the perimeter of cell stack 816 (corner 830 in this embodiment) is at the bottom. Low tack adhesive 806 is injected into the housing 818 and allowed to lay down on the bottom. The injection ports may be positioned to conform to the perimeter of the cell stack 816, which can be incorporated into the housing 818 to facilitate injection of the adhesive 806 into the housing 818 to seal the corners 830 of the cell stack 816 to the housing 818. After the adhesive 806 has set, the skin 818 may be rotated 90 until the next corner is at the bottom. The adhesive process is repeated until all desired perimeters of the cell stack 816 have been sealed or secured. Surface preparation for improving the seal of the housing to the stack periphery may include techniques to break the surface and increase the surface area in order to enhance the adhesive bond. For example, surface preparation may include chemical, mechanical, electrical, or thermal surface preparation, and combinations thereof. This may include, for example, chemical etching or mechanical roughening.

The housing may be manufactured, for example, by extrusion, to provide a geometry that facilitates securing the cell stack to the housing. For example, one or more grooves may be created within the housing so that the adhesive may be contained within a defined area to receive the perimeter of the cell stack. As shown in fig. 9, the housing 918 is provided with a scalloped recess 932 to provide an accumulator for placement of the adhesive 906.

In another embodiment of the present disclosure, a method of applying adhesive is provided that includes slowly rotating a housing in one direction while spraying a controlled amount of adhesive into the housing. The adhesive flows continuously towards the lowest point and forms a continuous thin layer which can condense to form a sealing ring around the inner wall of the housing. The thickness of the ring can be increased by further adding an adhesive.

In another embodiment of the present disclosure, a method of applying adhesive is provided that includes rapidly rotating a housing in one direction while spraying a controlled amount of adhesive into the housing at one or more points. The adhesive may be pressed against the inner wall of the housing by means of centrifugal force and may form a sealing ring when it sets.

An embodiment of the present disclosure is shown in fig. 10, which provides a method that includes rotating housing 1018 in one direction while spraying a controlled amount of adhesive 1006 to the housing.

In another embodiment of the present disclosure, the electrical purification apparatus may be assembled by sealing a portion of the perimeter of the cell stack with an adhesive by means of a mold. The cell stack may be inserted into the housing and then compressed with end plates at each end of the cell stack. An adhesive may then be applied to seal the periphery of the cell stack to the inner wall of the housing.

As shown in fig. 11, the perimeter of the cell stack (in this example, corner 1130 of cell stack 1116) can be inserted into a mold 1134. The low tack adhesive 1106 may be poured into the mold 1134 and allowed to set. The stack is then rotated to seal the remainder of the perimeter as shown in fig. 12, where an adhesive 1206 is shown at each corner 1230 of cell stack 1216. In some examples, the mold is made of a material to which the binder cannot adhere.

As shown in fig. 13, the cell stack 1316, all four corners of which are sealed, is inserted into the housing 1318 with a gap 1338 between the adhesive 1306 and the inner wall 1336 of the housing 1318. Additional adhesive is used to fill gap 1338 to seal cell stack 1316 to housing 1318 and prevent cross-leakage between flow manifolds.

In another embodiment shown in fig. 14, a membrane cell stack 1416 with a bracket assembly or corner support 1440 (which may be manufactured, for example, by extrusion or injection molding) may be used as a mold to encapsulate and seal the corners of the cell stack 1416. Corner supports 1440 (and 1540) then serve as anchors to attach the stack to housing 1542, as shown in fig. 15. Methods that may be used to secure the corner supports to the housing include plastic joining techniques such as ultrasonic welding. The casing 1542 (and 1642) is then inserted into the housing 1618 as shown in fig. 16, thus eliminating the need to pot the stack assembly directly to an external housing. Bracket assemblies or corner supports may also be used to secure the modular units to the enclosure.

In certain embodiments of the present disclosure, an electrically powered purification apparatus is provided that reduces or prevents inefficiencies due to greater electrical power consumption. The electrically powered purification apparatus of the present disclosure may provide a multi-pass flow configuration to reduce or prevent current inefficiencies. The multi-pass flow configuration may reduce current bypass or current leakage through the flow manifold by eliminating or reducing a direct current path between the anode and cathode of the electrical purification apparatus. As shown in fig. 17, an electrically powered purification apparatus 50 is provided that includes a cathode 1744 and an anode 1746. A plurality of alternating anion exchange membranes 1748 and cation exchange membranes 1750 are positioned between the cathode 1744 and the anode 1746 to provide a series of alternating ion diluting compartments 1752 and ion concentrating compartments 1754. Blocking spacers 1756 may be placed within one or more of the ion diluting compartment 1752 and the ion concentrating compartment 1754 in order to redirect fluid flow and current flow through the electrical purification apparatus 50, as shown by the arrows in fig. 17.

Fig. 18 shows an example of a spacer that can be used as a blocking spacer within an electrical purification apparatus. The spacer may include a screen portion 1858, a solid portion 1860, and a seal 1862. The sealing strip 1862 may be adhesively bonded to the adjacent film as shown in fig. 19. The sealing strip may improve the seal between the membrane and the spacer by providing a flat surface for bonding. In some examples, the spacer may be manufactured by injection molding, machining, hot pressing, or rapid prototyping.

The molding spacer may have a sufficient thickness so that the screen portion may be molded. The thickness may be greater than the thickness of the screen spacer. Thus, the inter-membrane distance of the blocking compartment may be larger than the distance in the adjacent compartment, resulting in a higher electrical resistance, which may be acceptable because the number of blocking spacers is limited.

The edge of the spacer at the solid portion is fixed and sealed to the inner wall of the housing. The solid portion 1860 of the spacer may be sufficiently rigid to withstand a pressure differential on both sides. Structural features such as ribs may be added to the solid portion to increase the stiffness of the material.

As shown in fig. 19, a first spacer assembly 1964 and a second spacer assembly 1966 may be provided. The blocking spacer 1956 is positioned between the first spacer assembly 1964 and the second spacer assembly 1966.

Fig. 20 shows an embodiment of an electrically powered purification apparatus of the present disclosure comprising three cross-flow electrodialysis devices. The cell stack 2016 is secured within a housing 2018. The barrier spacer 2056 is positioned within the cell stack 2016 to redirect the flow of fluid and current within the electrodialysis device, as shown by the arrows in fig. 20.

In another embodiment, a part of the periphery of the cell stack and the periphery of the blocking spacer are fixed to the inner side surface of the case by means of an adhesive.

As shown in fig. 21, the blocking spacer 2156 has a rounded edge 2168 that forms a recess for the adhesive 2106 when the spacer 2156 is inserted into the housing. The device can then be assembled as shown in fig. 22 by inserting multiple cell pairs 2216 and blocking spacers 2256 or multiple spacers into the housing 2218 and then compressing this assembly using end plates and/or end blocks at both ends. Adhesive 2206 can be applied sequentially to a portion of the periphery of the stack by potting.

Housing 2318 is then oriented so that the axis is vertical as shown in fig. 23A, and rim 2368 is ready to receive adhesive. As shown in fig. 23B, adhesive 2306 is applied to the groove formed by the rim 2368 on the blocking spacer 2356 to seal the spacer to the housing 2318. The adhesive can be injected, for example, through a small tube or conduit inserted through the end plate and/or end block.

In certain embodiments, additional components such as gaskets or O-rings may be used and positioned around the blocking spacer to help contain the liquid adhesive used to secure the spacer to the housing. In such embodiments, the adhesive may be the primary seal once it has cured. In another embodiment, an additional component such as a gasket or O-ring is designed to be the only seal between the blocking spacer and the housing, and adhesive 2206 located at only a portion of the perimeter of the cell stack may be used (see fig. 22). This may simplify the modular unit assembly by reducing or eliminating the need to seal the edge of the blocking spacer to the housing using an adhesive material.

In another embodiment, a cell-to-cell stack with dilution and concentration compartments in a single-pass flow configuration is first sealed in sections of a cylindrical housing to form a modular unit. The cells may then be joined together with the blocking spacers in between to form a multi-lane configuration. An advantage of this approach is that the stack can be sealed to the housing section using an adhesive at only a portion of the perimeter (e.g., the corners). The blocking spacer does not have to be sealed to the inner wall of the housing; but rather they are positioned between the modular units and sealed between the ends.

Fig. 24A, for example, shows first modular unit 2470 and second modular unit 2472 having flanges 2474 at the ends and having blocking spacer 2456 disposed therebetween. In fig. 24B, first modular unit 2470 and second modular unit 2472 are secured to one another. Flanges 2474 of first modular unit 2470 and second modular unit 2472 can be secured together. In some examples, flanges 2474 of first modular unit 2470 and second modular unit 2472 can be bolted together.

FIG. 25 shows another embodiment of a blocking spacer having a shield portion 2558, a solid portion 2560 and a bead 2562. The blocking spacer may be molded with a circular frame 2576, which may be sealed between the flanges with an adhesive or gasket. Alternatively, the frame may be molded from a thermoplastic material such that an adhesive or gasket is not necessary. Other methods for fabricating the barrier spacer will be apparent to those skilled in the art.

Alternatively, clamps, tie rods, or other securing techniques can be used to connect the modular units together. The design of the blocking spacer can be modified accordingly to accommodate the selected fixation technique.

In some embodiments of the present disclosure, methods for making a battery stack are provided. The first spacer assembly may be prepared by securing the first ion exchange membrane to the second ion exchange membrane at a first portion of the perimeter. At the second portions of the first and second ion exchange membranes, the perimeter may be folded to provide end folds. The spacer may be provided between the first ion exchange membrane and the second ion exchange membrane. The second spacer assembly may be similarly prepared. The end folds of the first spacer assembly may be aligned with the end folds of the second spacer assembly such that the end folds of the second ion exchange membrane are secured to the end folds of the ion exchange membrane of the second spacer assembly. Thereafter, the end folds may collapse and the spacer may be placed between the spacer assemblies. As the spacer assemblies are compressed, the compartments are created to provide fluid flow between the spacer assemblies in a different direction than fluid flow within each of the first and second spacer assemblies.

As shown in fig. 26, a first spacer assembly may be prepared by fixing a first anion exchange membrane 2602 to the first cation exchange membrane 2600 at a first portion of the periphery. In this example, the first portion of the perimeter is secured by thermal bonding 2678. At the second portions of the first anion exchange membrane and the first cation exchange membrane, the perimeter may be folded to provide end folds 2680. A spacer 2604 may be provided between the first anion exchange membrane 2602 and the first cation exchange membrane 2600.

The second spacer assembly may be similarly prepared. As shown in fig. 27, the end folds 2780 of the first spacer assembly may be aligned with and overlap the end folds 2784 of the second spacer assembly such that the end folds of the first cation exchange membrane are secured to the end folds of the anion exchange membrane of the second spacer assembly. The folded-over overlap of the end portions may be secured by thermal bonding, adhesives, or mechanical techniques. The end folds can then be collapsed, as shown in fig. 28, and spacers 2804 can be placed between the spacer assemblies. As the spacer assemblies are compressed, compartments are created to provide fluid flow streams 2986 between the spacer assemblies in a different direction than the fluid flow streams 2988 within each of the first and second spacer assemblies, as shown by the arrows in fig. 29.

By using thermal bonding techniques to prepare the spacer assembly and the final cell stack, the provided process may allow for convenient assembly and may result in an electrically powered purification device with a faster overall assembly time. The narrow heat seal provides a larger flow channel, which can result in higher membrane utilization, which can increase the efficiency of the overall electrokinetic purification apparatus. In some embodiments, with thermal bonding, additional reinforcing strips of polymeric material, such as polypropylene or polyethylene, may be used to reinforce the thermal bonding areas and provide a more secure seal. By thermally bonding the membranes prior to collapsing and compressing the membranes, ease of assembly may also be facilitated since there may be more room for appropriate bonding devices and means to assist in the bonding process. Thermal bonding techniques may also prevent leakage in the membrane stack. This process may also reduce the compressive force to the membrane spacers in order to maintain cell stack integrity, resulting in a smaller pressure drop through the modular unit.

In some embodiments, a binder may be used to secure the ion exchange membranes and spacers within the cell stack. The adhesives that may be useful in preparing the cell stack may have particular features or characteristics that allow for proper sealing of the components within the cell stack and securing the cell stack within the housing of the electrical purification apparatus. These properties may include the tack, gel time, cure temperature, and elastic properties of the adhesive. By varying the properties of the adhesive, it has been found that the bond strength between the membrane stack and the housing can be enhanced and leaks within the electrical purification apparatus can be reduced or eliminated.

In some cases, epoxy or epoxy-based materials or polyurethane-based materials may be used. This may be due to their thermal, mechanical and chemical properties that allow them to provide proper sealing of the membranes to each other and of the cell stack to the housing.

The epoxy resin or epoxy-based material may comprise a resin and a curing agent. In order to provide a proper seal with the membrane or with the housing, the resin may need to be crosslinked. Such crosslinking may be achieved by chemically reacting the resin with a suitable curing agent. The curing agent may be selected from the group consisting of aliphatic amines, amido-amines, alicyclic amines, and aromatic amines. The curing agent may provide specific characteristics to the adhesive including, but not limited to, tack, open time, cure time, permeability, wetting ability, mechanical strength, and chemical resistance after curing.

Polyurethanes or polyurethane-based materials can be produced by the polyaddition reaction of the isocyanines with polyols (polyols) in the presence of a catalyst. The reaction can provide a polymer comprising urethane-bonded-RNHCOOR'.

When an adhesive is required to properly secure the films to each other, in some embodiments it may be desirable for the adhesive to remain to some extent on the predetermined glue line or bead. If, for example, the viscosity of the adhesive is too low, the adhesive may detach or drip from the glue line or the sealing strip. If the adhesive is too tacky, spreading of the adhesive may become too difficult.

In certain embodiments, it may be desirable to use an adhesive with a similar thermal expansion as the films to secure the films to each other. This may prevent or reduce cracking or wrinkling at the film-adhesive interface. The concentration of the amine-based curing agent may be varied in order to determine a suitable binder for use in electrical purification apparatus applications. For example, aliphatic amines have a straight carbon backbone, which can provide a high degree of flexibility for thermal expansion. The use of this type of curing agent may allow the side seam to expand with the film. Cycloaliphatic amines and aromatic amine curatives have aromatic rings in their backbone, which can provide rigid elastomeric properties.

In certain embodiments of the present disclosure, the adhesive that may be used to secure the films to each other may have a viscosity in the range of from about 1000 to about 45000 cps at ambient temperature. This may provide a gel time in the range of from about 15 minutes to about 30 minutes. The binder may have a shore D hardness ranging from about 30 to about 70 at ambient temperature.

The adhesive may be applied by any suitable means and may be applied by an automated or manual process. The adhesive produced seam may have a thickness in the range of about 0.25 inches to about 1.5 inches, and a tack thickness in the range of about 20 mils to about 50 mils. The adhesive may be cured by using ultraviolet light, ambient temperature, accelerated temperature, or the like.

The adhesive that may be used to secure the membrane cell stack to the housing may have a low tack, which may be achieved by adding additional diluent to the mixed adhesive. By adding a diluent, a less viscous binder can be obtained and the binder can allow easier application of the binder. Lower viscosity may also provide more penetration into the porous matrix and better wetting on non-porous surfaces. In certain examples, the diluent may be selected from the group consisting of diglycidyl ethers, glycidyl phenyl glycidyl ethers, and combinations thereof.

The adhesive used to secure the cell stack to the housing may be more rigid than the adhesive used to secure the membranes to each other. The adhesive used to secure the cell stack to the housing may be formulated to have sufficient mechanical strength to withstand the weight of the membrane cell stack and not deform under the flow pressure.

In certain embodiments of the present disclosure, the adhesive used to secure the cell stack to the housing may have a viscosity in a range from about 300 cps to 2000 cps at ambient temperature. The gel time of the adhesive may range from about 30 minutes to about 60 minutes. The binder may have a shore D hardness in the range of about 45 to 80 at ambient temperature.

The housing in which the membrane cell stack is placed and secured to provide the electrochemical purification apparatus may be made of any suitable material to allow and retain fluid and current flow within the apparatus. For example, the housing or casing may be constructed of polysulfone, polyvinyl chloride, polycarbonate, or epoxy impregnated fiberglass. The material for the outer shell may be made by an extrusion process, injection molding, or other process that generally provides a dense structure with a generally smooth interior. To enhance the adhesive bond between the housing and the membrane cell stack, which may fail due to continuous fluid flow forces, a portion of the interior surface of the housing that secures the membrane cell stack may be treated or modified. Surface preparation to improve the sealing of the housing to the stack periphery may include techniques to break the surface and increase the surface area to enhance the adhesive bond. For example, surface preparation may include chemical, mechanical, electrical, or thermal surface preparation, and combinations thereof. This may include, for example, chemical etching or mechanical roughening.

In certain embodiments, adhesive injection ports within the housing are used to assist in delivering adhesive to desired areas within the housing in order to secure the membrane cell stack to the housing. One or more adhesive injection ports may be used to introduce adhesive to the housing. More than one adhesive port may be utilized at each fixation point within the housing. In certain embodiments, three adhesive injection ports may be provided in a particular arrangement to distribute adhesive to a fixed point in an appropriate manner. The adhesive injection ports may be placed in a straight line or may be spread out into a particular design or pattern to achieve the desired adhesive delivery. In examples where a low tack adhesive is used, it may penetrate into the channels of the membrane cell stack in order to enhance the bond between the membrane cell stack and the housing. By injecting the adhesive in this manner, the amount of adhesive being used and the exotherm generated by the adhesive can be monitored.

In certain embodiments of the present disclosure, the membranes may be secured to each other and to spacers within the membrane cell stack by mechanical sealing techniques. The sealing may be achieved by the formation of ridges or grooves on at least one of the membrane and the spacer used in the electrical purification apparatus. The ridges or grooves on the first membrane or spacer may mate with the ridges or grooves on the second membrane or spacer. The ridges or grooves on the first membrane or spacer may interlock with the ridges or grooves on the second membrane or spacer. For example, the ridges or grooves on the first membrane or spacer may be male ridges or fittings that mate with the ridges or grooves on the second membrane or spacer, which may be female ridges or fittings. An ion exchange membrane, such as a cation exchange membrane or an anion exchange membrane, may be positioned and secured between the first spacer and the second spacer. In certain embodiments, once a series of spacers and ion exchange membranes have been assembled to form a plurality of concentrate and dilute flow compartments, the compartments may be filled with resin, for example in the form of a resin syrup or resin suspension.

Fig. 30 shows an example of an injection molded diluent spacer 3004 having a groove 3090 for mating with a seal on both faces of spacer 3004. One end of each flow compartment 3092 can be closed to only an opening 3094, which holds the ion exchange resin droplets, but can allow fluid flow. The other end 3096 of spacer 3004 may be open for resin filling. A slot 3098 may be present at the end to accommodate the resin retention plate. The concentrating spacer may be constructed in the same manner. In certain examples, the concentrating spacer may be thinner than the diluting spacer because, in certain embodiments, the concentrating flow may be less than the flow through the diluting compartment.

Fig. 31 shows a cross-sectional view of a cell stack constructed by the spacer 3104 and the cation exchange membrane 3100 and the anion exchange membrane 3102 before assembly. The female feature 3101 on the first spacer 3104a can be mated to the male feature 3103 on the second spacer 3104 b. The male feature 3103 on the second spacer 3104b may also mate with the female feature 3101 on the third spacer 3104 c.

To enhance the transfer of ions through the resin droplets and the membrane, it may be desirable to have the resin droplets closely packed. This may be a dilution compartment which is particularly advantageous in ultrapure water applications. It has been found that there are many ways to increase the packing density. For example, the resin may be soaked in a concentrated salt solution, such as sodium chloride, and then slurried into the compartment. During operation of the electrical purification apparatus, as the dilution stream is deionized, the resin within the dilution compartment may swell. The resin may also be soaked in a concentrated salt solution, such as sodium chloride, and then dried. The resin may then be suspended in an air stream and then blown into the compartment. During operation, the resin in both the diluting compartment and the concentrating compartment may swell when exposed to fluid, and the resin in the diluting compartment will further swell when the diluting stream is deionized. In another example, the concentration compartment may be filled before the dilution compartment. The membrane will be allowed to bulge into the dilution compartment and the dilution compartment may then be filled. Expansion of the resin in the dilution compartment during operation may be constrained by the resin being packed into the concentration compartment, thereby increasing the packing density.

Fig. 32 shows a cross-sectional view of a portion of an assembled stack of spacers 3204, including 3204a, 3204b, and 3204c, and membranes, and a detail view of the mechanical seal interlock. As shown in the detail view, once the stack with the desired number of cell pairs is assembled, the compartment 3292 can be filled with resin. Resin slurry in the fluid is pumped into the compartment. The resin may be held within the opening 3294 at the bottom of the compartment while the resin carrier fluid flows through. When the compartments are filled, the slotted plate is slid into place to hold the resin within the compartments. The stack may then be rotated 90 ° and the diluting compartments may be filled with resin in a similar manner.

Fig. 33 shows a portion of a membrane cell stack 3305 with a resin holding plate 3307 in place. Membrane cell stack 3305 may be secured within the housing at specific points along the perimeter of cell stack 3305. For example, the cell stack can be secured at one or more corners 3330 of cell stack 3305.

In another embodiment, an over-molded thermoplastic rubber (TPR) seal may be used to seal the membrane to the spacer. After the stack of spacers and membranes is assembled and compressed, the concentrate and dilute flow compartments are filled with resin. Figure 34 shows a dilute spacer 3404 with a rim 3407 and an overmolded seal 3409. The over-molded seals may be present on both sides of the spacer. The concentrating spacer may be similarly constructed. In certain examples, the concentrated spacer may be configured to be thinner than the dilute spacer, but may not include an over-molded seal.

Fig. 35 is a cross-sectional view through a portion of a stack of spacers and membranes, including a concentration spacer 3511 and a dilution spacer 3513. Openings 3594 retain resin within compartment 3592, and openings or slots 3598 at opposite ends of compartment 3592 allow resin to fill. In this particular embodiment, a circular rim 3507 is shown, although other rim shapes can be used, such as rectangular, square, or polygonal, so long as the final cell stack can be reasonably secured to the housing. In some embodiments, the edge 3507 can eliminate the need for a housing. The radial over-molded seals 3509 can separate dilute and concentrate inlet/outlet manifolds and thus eliminate the need for corner fixings or potting. The stack may be compressed to seal the membrane and spacers together prior to adding resin to the stack. This may be achieved, for example, by temporary tie bars or clamps.

FIG. 36 is a cross-sectional view showing the resin retention plate 3607 in place after the resin fills the dilution compartment 3615.

In certain embodiments, the seal achieved by the over-molded seal and the mating of the male and female features may be used together to provide a fixed stack of membrane cells. The membrane may be sealed to the spacer using male and female features, and simultaneously radial over-molding the seal and the seal in the rim may seal the dilute spacer to the concentrated spacer. In such embodiments, it may not be necessary to use a housing or corner seals to seal the cell stack to the housing.

In some embodiments, injection molded spacer 3704 is provided to include screen region 3725, as shown in fig. 37. This figure shows the fluid flow direction 3727. The openings are provided in two opposing edges 3729 and 3731. The wire may be retracted to form the opening prior to removing the part from the mold.

Fig. 38A and 38B show details of the opening in the edge 3829 (e.g., at 3833) as discussed with reference to fig. 37. Fig. 38A and 38B also show a male feature 3803 that can interlock with the female feature 3801.

Dashed parting lines are shown in fig. 38B. The spacer may be molded with a set of strands above the parting line 3835 and a set of strands below the parting line 3835 of the mold. The strands of the screen spacer as shown in fig. 38B have a semi-circular cross-section and the two sets of strands are oriented perpendicular to each other. The cross-sectional shape, orientation, and number of occurrences of the strands may be varied to promote fluid mixing and/or reduce pressure drop. Ribs or baffles may be molded into the spacer to form flow channels and improve flow distribution.

In certain embodiments, male and female features are molded on the top and bottom, respectively, of the edge containing the inlet and outlet openings 3833.

The choice of material for the spacer may depend on its ability to be molded with thin walls and small dimensions, such as on the order of about 0.060 inches (1.5 mm) or less. The material may also have the ability to be molded with small holes, preferably on the order of about 0.030 inches (0.75 mm) or less. The material may be suitably elastic to allow proper interlocking of the male and female features and may be chemically compatible with the fluid to be purified.

Fig. 39 shows a portion of a stack of spacers and membranes. As shown, the male feature 3903 interlocks with the female feature 3901. Similarly, in fig. 40, the male feature 4003 interlocks with the female feature 4001. The cation exchange membrane 4000 and the anion exchange membrane 4002 are fixed between the spacers. The spacer 4037 for the first flow seals the edge of the membrane leading to the second flow, while the spacer 4039 for the second flow seals the edge of the membrane leading to the first flow.

In certain embodiments of the present disclosure, the flow within the compartment may be regulated, redistributed or redirected to provide greater contact of the fluid with the membrane surface within the compartment. The compartment may be constructed and arranged to redistribute fluid flow within the compartment. The compartment may have an obstruction, protrusion, ridge, flange or baffle that may provide a structure to redistribute flow through the compartment. The obstacles, protrusions, bumps, flanges or baffles may be formed as part of the ion exchange membrane, spacers, or may be additional separate structures provided within the compartment. The barrier, protrusion, bump, flange or baffle may be formed by providing an extension from the adhesive securing the ion exchange membranes to each other. The spacers may be impregnated with a thermoplastic rubber to form protrusions that may be bonded to adjacent membranes using an adhesive. The thermoplastic rubber may be applied to the spacer using a process such as hot pressing or rotary screen printing. The compartment may or may not contain an ion exchange resin.

As shown in fig. 41, first ion exchange membrane 4151 and second ion exchange membrane 4153 are shown having first spacer 4155 and second spacer 4157 positioned adjacent thereto. The first flow 4159 is shown as flowing in parallel with the flow of the second flow 4161 because the second spacer 4157 has baffles that redistribute the flow from the inlet 4163 of the spacer 4157 around the first baffle 4165 and around the second baffle 4167 and through the outlet 4169.

As shown in fig. 42, first ion exchange membrane 4251 and second ion exchange membrane 4253 are shown having first spacer 4255 and second spacer 4257 positioned adjacent thereto. The first flow 4259 is shown to flow perpendicular to the flow of the second flow 4261 because the second spacer 4257 has baffles that redistribute the flow from the inlet 4263 of the spacer 4257, around the first baffle 4265, around the second baffle 4267, and through the outlet 4269.

Fig. 43 and 44 show additional embodiments with compartments for two flows formed by injection molded spacers. In FIG. 43, the flow path for the second flow 4361 may be co-current or counter-current to the first flow 4359. In fig. 44, the flow path for the second stream 4461 may be perpendicular to the first stream 4459. Selected solid portions of the spacer may be bonded to adjacent membranes using an adhesive. Alternatively, the membrane may be thermally bonded to the spacer, for example by ultrasonic, vibration or laser welding. As shown in these figures, the dashed arrows indicate the flow of the second stream in the inlet and outlet manifolds. These manifolds are not the inlet and outlet of the accompanying flow compartment for the second stream. Thus, it is expected that leakage current along the manifold between the anode and cathode will be reduced.

In some embodiments of the present disclosure, a method of providing a source of potable water is provided. In certain embodiments, methods are provided to facilitate the production of potable water from seawater. The method may include providing an electrically powered decontamination apparatus including a cell stack. The method may further comprise fluidly connecting the seawater feed stream to an inlet of an electrically powered purification apparatus. The method may further comprise fluidly connecting an outlet of the electrically powered purification apparatus to a point of use. The seawater or river water may have a concentration of total dissolved solids in the range of about 10000 to about 45000 ppm. In certain examples, the seawater or river water may have a concentration of total dissolved solids of about 35000 ppm.

In such an embodiment, the cell stack may comprise alternating ion diluting compartments and ion concentrating compartments. Each ion diluting compartment may be constructed and arranged to provide fluid flow in a first direction. Each ion concentrating compartment may be constructed and arranged to provide fluid flow in a second direction different from the first direction, as described above. Further, each of the ion concentrating and ion diluting compartments may be constructed and arranged to provide a predetermined percentage of surface area or membrane utilization for fluid contact with each of the alternating ion diluting and ion depleting compartments. As noted above, it has been found that greater membrane utilization provides greater efficiency in the operation of an electrokinetic purification apparatus. In certain embodiments, a membrane utilization greater than 65% can be achieved. In other embodiments, a membrane utilization greater than 75% may be achieved. In certain other embodiments, the membrane utilization that can be achieved can be greater than 85%.

At least one of the ion diluting compartment and the ion concentrating compartment may comprise a spacer. The spacer may be a blocking spacer. This may allow the seawater feed to pass through multiple stages or lanes of the electrically powered purification apparatus to provide a source of potable water.

The first fluid flow direction and the second fluid flow direction may be selected and provided by means of the construction and arrangement of the compartments. Using the first fluid flow direction as the direction extending along the 0 ° axis, the second fluid flow direction may extend in a direction at any angle greater than zero degrees and less than 360 °. In certain embodiments of the present disclosure, the second fluid flow path may extend at a 90 ° angle or perpendicularly with respect to the first fluid flow path. In other embodiments, the second fluid flow path may extend at a 180 ° angle relative to the first fluid flow path.

The method may further comprise redistributing the fluid within at least one of the alternating ion diluting compartments and ion concentrating compartments. One or more compartments may be constructed and arranged to redistribute or redirect fluid flow. This may be achieved by using a specific spacer or membrane defining a compartment which may provide a configuration for redistributing the flow of fluid, as described above.

The electrical purification apparatus may further include a housing enclosing the cell stack. At least a portion of the perimeter of the cell stack may be secured to the housing. The electrically powered purification apparatus may further include a frame or support structure disposed between the housing and the cell stack. The frame may be adjacent to or connected to the cell stack to provide a modular unit. The electrically powered decontamination apparatus may further comprise a second modular unit that may be secured within the housing. The second modular unit may be secured within the housing such that the ion exchange membrane of the first modular unit is adjacent to the ion exchange membrane of the second modular unit.

The method of providing a source of potable water may include redirecting at least one of an electrical current and a fluid flow between the first modular unit and the second modular unit. This may be achieved, for example, by providing a blocking spacer between the first modular unit and the second modular unit.

A bracket assembly may be disposed between the frame and the enclosure to secure the modular unit to the enclosure.

Other types of feed water including different total dissolved solids concentrations may be treated or processed using the apparatus and methods of the present disclosure. For example, brackish water having a total dissolved solids amount in the range of about 1000 ppm to about 10000 ppm can be treated to produce potable water. Brines having total dissolved solids in the range of about 50000 ppm to about 150000 ppm can be treated to produce drinking water. In some embodiments, brines having total dissolved solids in the range of about 50000 ppm to about 150000 ppm may be treated to generate water having lower total dissolved solids for disposal, e.g., discharge to a body of water such as the ocean.

Although exemplary embodiments of the present disclosure have been disclosed, many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the disclosure and its equivalents, as set forth in the following claims.

Those skilled in the art will readily appreciate that the various parameters and configurations described herein are intended to be exemplary and that the actual parameters and configurations will depend upon the particular application for which the disclosed electrical purification apparatus and method are directed. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments described herein. For example, those skilled in the art will recognize that devices and components thereof according to the present disclosure may further comprise a system network or be a component of a water purification or treatment system. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the disclosed electrical purification apparatus and method may be practiced otherwise than as specifically described herein. The present apparatus and methods relate to each individual feature or method described herein. In addition, any combination of two or more such features, devices, or methods, provided such features, devices, or methods are not mutually inconsistent, is included within the scope of the present disclosure.

For example, the housing may have any suitable geometry such that one or more membrane cell stacks or modular units may be secured therein. For example, the housing may be cylindrical, polygonal, square, or rectangular. With respect to thin cell stacks and modular units, any suitable geometry is acceptable as long as the cell stack or modular unit can be secured to the housing. For example, the membrane or spacer may be rectangular in shape. In some embodiments, no housing may be required. The geometry of the membrane and the spacer may be any suitable geometry such that the membrane and the spacer may be secured within the cell stack. In some embodiments, a specific number of corners or vertices on the cell stack may be desired. For example, three or more corners or vertices may be required for securing the cell stack to the housing. In certain embodiments, the geometry of any of the housing, the cell stack, the membrane, and the spacer may be selected to accommodate operating parameters of the electrical purification apparatus. For example, the spacer may be asymmetric to accommodate flow rate differences between the dilute and concentrate flows.

In addition, it will be appreciated that various alterations, modifications, and improvements will readily occur to those skilled in the art. Such alterations, modifications, and improvements are intended to be part of this disclosure, and are intended to be within the spirit and scope of the disclosure. For example, an existing facility may be retrofitted to utilize or include any one or more aspects of the present disclosure. Thus, in some cases, the devices and methods may include connecting or configuring existing facilities to include electrically powered decontamination devices. Accordingly, the foregoing description and drawings are by way of example only. Furthermore, the depictions in the figures do not limit the present disclosure to the specifically illustrated illustrations.

As used herein, the term "plurality" refers to two or more items or components. The terms "comprising," including, "" carrying, "" having, "" containing, "and" involving, "whether in the specification or the claims, are open-ended terms, i.e., meaning" including, but not limited to. Thus, use of such terms is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. With respect to the claims, the transitional word "consisting of … …" and "consisting essentially of … …" is a closed or semi-closed transitional word, respectively. Use of ordinal terms such as "first," "second," "third," etc., in the claims to define claim elements does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the order) to distinguish the claim elements.

Claims (11)

1. An electrical purification apparatus comprising a cell stack, comprising:

a first compartment comprising a first cation exchange membrane and a first anion exchange membrane, the first compartment constructed and arranged to provide direct fluid flow in a first direction between the first cation exchange membrane and the first anion exchange membrane;

a second compartment comprising a first anion exchange membrane and a second cation exchange membrane to provide direct fluid flow in a second direction between the first anion exchange membrane and the second cation exchange membrane, each of the first compartment and the second compartment being constructed and arranged to provide fluid contact greater than 85% of the surface area of the first cation exchange membrane, the first anion exchange membrane, and the second cation exchange membrane.

2. The electrical purification apparatus of claim 1, further comprising a housing enclosing the cell stack, at least a portion of a perimeter of the cell stack being secured to the housing.

3. The electrical purification apparatus of claim 2, further comprising a frame positioned between the housing and the cell stack to provide a first modular unit.

4. The electrical purification apparatus of claim 3, further comprising a second modular unit secured within the housing.

5. The electrical purification apparatus of claim 4, further comprising a blocking spacer positioned between the first modular unit and the second modular unit.

6. The electrical purification apparatus of claim 3, further comprising a bracket assembly positioned between the frame and the housing.

7. The electrical purification apparatus of claim 1, wherein the first direction is perpendicular to the second direction.

8. The electrical purification apparatus of claim 1, further comprising a flow redistributor within at least one of the first dilution compartment and the second dilution compartment.

9. The electrical purification apparatus of claim 1, wherein at least one of the first and second compartments is constructed and arranged to provide flow reversal within the compartment.

10. The electrical purification apparatus of claim 1, wherein at least one of the first compartment and the second compartment comprises a spacer.

11. The electrical purification apparatus of claim 10, wherein the spacer is a blocking spacer.