Techniques for promoting current efficiency in electrochemical separation systems and methods

• US 9,139,455 B2
• Filed: 11/11/2011
• Issued: 09/22/2015
• Est. Priority Date: 11/12/2010
• Status: Active Grant

• Current Assignee: Evoqua Water Technologies LLC
• Original Assignee: Evoqua Water Technologies LLC
• Inventors: Liang, Li-Shiang, Yeo, Keng Hoo, Salvo, Lawrence J.
• Primary Examiner(s): Phasge, Arun S
• Application Number:
  US13/294,238
• Publication Number:
  US 20120118742A1
• Time in Patent Office: 1,411 Days
• Field of Search: 204/632, 204/630
• US Class Current: 1/1
• CPC Class Codes: B01D 2315/10 Cross-flow filtration
• CPC Class Codes: B01D 61/463 comprising the membrane sequence AC or CA, where C is a cation exchange membrane
• CPC Class Codes: B01D 61/48 having one or more compartments filled with ion-exchange material , e.g. electrodeionisation
• CPC Class Codes: B01D 61/50 Stacks of the plate-and-frame type
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C02F 1/4693 electrodialysis
• CPC Class Codes: C02F 1/4695 electrodeionisation
• CPC Class Codes: C02F 2201/46 Apparatus for electrochemical processes
• CPC Class Codes: C25B 9/00 Cells or assemblies of cells; Constructional parts of cells; Assemblies of constructional parts, e.g. electrode-diaphragm assemblies; Process-related cell features
• CPC Class Codes: C25B 9/19 with diaphragms
• CPC Class Codes: C25B 9/70 Assemblies comprising two or more cells
• CPC Class Codes: H01F 41/02 for manufacturing cores, coils, or magnets H01F41/14 takes precedence; for dynamo-electric machines H02K15/00
• CPC Class Codes: Y02A 20/124 Water desalination
• CPC Class Codes: Y10T 29/49002 Electrical device making
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor

Abstract

An electrochemical separation system may be modular and may include at least a first modular unit and a second modular unit. Each modular unit may include a cell stack and a frame. The frame may include a manifold system. A flow distribution system in the frame may enhance current efficiency. Spacers positioned between modular units may also enhance current efficiency of the system.

Claims

1. An electrochemical separation system, comprising:

a first electrode;

a second electrode;

a first electrochemical separation modular unit including a plurality of alternating depleting compartments and concentrating compartments positioned between the first and second electrodes;

a second electrochemical separation modular unit including a plurality of alternating depleting compartments and concentrating compartments, the second electrochemical separation modular unit arranged in cooperation with the first electrochemical separation modular unit and positioned between the first electrochemical separation modular unit and the second electrode; and

a spacer, disposed between and adjacent the first and second electrochemical separation modular units, configured to reduce current loss within the system,

wherein each of the first and second electrochemical separation modular units includes a cell stack defining the plurality of alternating depleting compartments and concentrating compartments, and a support system configured to maintain vertical alignment of the cell stack, the support system comprising a frame surrounding the cell stack, and

wherein the frame includes a manifold system and a flow distribution system in fluid communication with the manifold system, the flow distribution system comprising at least one bypass path configured to reduce current loss within the system.

2. The system of claim 1, wherein the spacer is configured to promote current flow to the depleting and concentrating compartments within the system.

3. The system of claim 1, wherein the first and second electrochemical separation modular units are arranged in parallel.

4. The system of claim 1, wherein the first and second electrochemical separation modular units are removable.

5. The system of claim 4, wherein the first and second electrochemical separation modular units are mounted in a vessel.

6. The system of claim 5, further comprising a source of water to be treated fluidly connected to an inlet of the vessel.

7. The system of claim 6, wherein the plurality of depleting compartments and concentrating compartments each has an inlet in fluid communication with the inlet of the vessel.

8. The system of claim 1, wherein the flow distribution system comprises an insert, and wherein the frame defines a recess configured to receive the insert.

9. The system of claim 8, wherein the insert defines a lattice structure configured to promote uniform flow distribution to the cell stack.

10. The system of claim 1, wherein the first and second electrochemical separation modular units are configured to provide non-radial flow within the system.

11. The system of claim 1, wherein the first and second electrochemical separation modular units are configured to provide a uniform liquid flow velocity profile within the system.

12. The system of claim 1, wherein the system is constructed and arranged to achieve at least about 85% fluid contact with respect to surface area of ion exchange membranes defining the electrochemical separation modular units.

13. The system of claim 1, wherein at least one of the depleting compartments and concentrating compartments comprises a blocking spacer or a flow redistributor.

14. The system of claim 1, wherein the system is configured such that a direction of flow through the depleting compartments is different than a direction of flow through the concentrating compartments.

15. The system of claim 1, wherein the system is configured such that the direction of flow through the depleting compartment is substantially perpendicular to the direction of flow through the concentrating compartments.

16. An electrochemical separation system, comprising:

a first electrode;

a second electrode;

a first electrochemical separation modular unit including a cell stack defining a plurality of alternating depleting compartments and concentrating compartments positioned between the first and second electrodes, and a frame surrounding the cell stack, the frame having a manifold system and a flow distribution system in fluid communication with the manifold system, the flow distribution system comprising at least one bypass path configured to reduce current loss within the electrochemical separation system;

a second electrochemical separation modular unit including a cell stack defining a plurality of alternating depleting compartments and concentrating compartments, and a frame surrounding the cell stack, the frame having a manifold system and a flow distribution system in fluid communication with the manifold system, the flow distribution system comprising at least one bypass path configured to reduce current loss within the electrochemical separation system, the second electrochemical separation modular unit arranged in cooperation with the first electrochemical separation modular unit and positioned between the first electrochemical separation modular unit and the second electrode; and

a spacer, disposed between and adjacent the first and second electrochemical separation modular units, configured to reduce current loss within the system.

17. The system of claim 16, wherein the system is constructed and arranged to achieve at least about 85% fluid contact with respect to surface area of ion exchange membranes defining the electrochemical separation modular units.

18. The system of claim 16, wherein at least one of the depleting compartments and concentrating compartments comprises a blocking spacer or a flow redistributor.

19. The system of claim 16, wherein the system is configured such that the direction of flow through the depleting compartment is substantially perpendicular to the direction of flow through the concentrating compartments.

20. The system of claim 16, wherein each flow distribution system comprises an insert, and wherein each frame defines a recess configured to receive the insert.