WO2000067906A9 - Apparatus and method of recirculating electrodeionisation - Google Patents
Apparatus and method of recirculating electrodeionisation Download PDFInfo
- Publication number
- WO2000067906A9 WO2000067906A9 PCT/US2000/011936 US0011936W WO0067906A9 WO 2000067906 A9 WO2000067906 A9 WO 2000067906A9 US 0011936 W US0011936 W US 0011936W WO 0067906 A9 WO0067906 A9 WO 0067906A9
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- water
- flow path
- deionising
- exchange material
- holding tank
- Prior art date
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D61/00—Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor
- B01D61/42—Electrodialysis; Electro-osmosis ; Electro-ultrafiltration; Membrane capacitive deionization
- B01D61/44—Ion-selective electrodialysis
- B01D61/46—Apparatus therefor
- B01D61/48—Apparatus therefor having one or more compartments filled with ion-exchange material, e.g. electrodeionisation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J47/00—Ion-exchange processes in general; Apparatus therefor
- B01J47/02—Column or bed processes
- B01J47/06—Column or bed processes during which the ion-exchange material is subjected to a physical treatment, e.g. heat, electric current, irradiation or vibration
- B01J47/08—Column or bed processes during which the ion-exchange material is subjected to a physical treatment, e.g. heat, electric current, irradiation or vibration subjected to a direct electric current
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/4604—Treatment of water, waste water, or sewage by electrochemical methods for desalination of seawater or brackish water
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/46—Treatment of water, waste water, or sewage by electrochemical methods
- C02F1/469—Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
Definitions
- the present invention relates to an apparatus for a method of recirculating electrodeionisation involving improved purification of purified water.
- Apparatus and methods for electrodialysis to provide purified water are well known, see for example our GB-A-2311999 and US 4687561.
- water to be purified is passed along a deionising path set between or along an anode and a cathode.
- the application of a potential difference between the anode and cathode causes anions and cations in the impure water to migrate towards their respective attracting electrodes through perm- selective membranes.
- a concentrating path is arranged therewith to collect and remove the unwanted anions and cations.
- the purified outflow water from such apparatus is then available for use.
- the general rates of flow of water through such apparatus do not allow a significant volume of purified water to be available for use quickly.
- the alternative is to collect the purified outflow water in a holding tank, from which a larger volume of water could be drawn when desired.
- water held in a tank especially that at high purities such as ⁇ O.l ⁇ S/cm, absorbs impurities from the environment, such as carbon dioxide from the atmosphere thus increasing its conductivity.
- an electrodeionisation apparatus comprising a first deionising flow path for water to be purified through an anion exchange material and/or a cation exchange material, in either order where both materials are used, and an integral second deionising flow path through an anion exchange material and a cation exchange material, in either order, wherein the outflow from the first path is held in a holding tank prior to passage through the second flow path, and the outflow from the second path is available for use.
- part or all of the second path outflow could be returned to the holding tank, e.g. when not required for use.
- Outflow from the second path may be passed around a ringmain with one of more take-off points before any remaining water is returned to the tank.
- purified water held in the holding tank could be separately made available for use.
- the present invention could provide for the provision of purified water from the holding tank directly, and/or of further purified water available directly from the outflow of the second deionising flow path. Water from the outflow of the second deionising flow path will usually be at a higher purity than water in the holding tank.
- the holding tank may, and generally will, however hold a relatively substantially volume of purified water, all of which is immediately available for use, whilst the time for collection of direct further purified water from the outlet of the second deionising flow path is dependent on the flow rate therefrom.
- the anion exchange material is an anion exchange resin
- the cation exchange material is a cation exchange resin
- the exchange materials are held in separated chambers.
- the first deionising flow path involves both an anion exchange material and a cation exchange material in either order.
- the anode and/or cathode could be housed within chambers housing the anion and/or cation exchange materials.
- the anode and/or cathode are housed in chambers separate from the first and second deionising flow paths.
- the anode and/or cathode are not separate from either the first and/or second deionising flow paths.
- the chamber for the anion exchange material of the first deionising flow path is adjacent the chamber for the anion exchange material for the second deionising flow path
- the chamber for the cation exchange material of the first deionising flow path is adjacent the chamber for the cation exchange material for the second deionising flow path.
- the water to be purified or further purified passes through an anion exchange material first, followed by passage through a cation exchange material.
- the apparatus also preferably includes a concentrating chamber into which the anions and cations desired to be removed from the water are concentrated and removed from the electrodeionisation apparatus.
- the apparatus could include a concentrating chamber adjacent each anion and/or cation exchange material chamber.
- the apparatus includes at least a centrally arranged concentrating chamber.
- At least one of the or any anode chambers, cathode chambers, and concentrating chambers has a flushing stream passing therethrough to remove electrode gases and/or the unwanted ions.
- Purified and repurified water from the first and/or second flow paths could be used for the or each flushing stream.
- Such water could be passed successively through two or more of the anode chamber (s), cathode chamber (s) and/or concentrating chambers (s) .
- the flushing stream runs countercurrent to the water flow through the, or at least one of, the adjacent purified water chambers.
- the electrodeionisation apparatus is a stack comprising seven chambers, a first chamber housing an anode, a second chamber containing cation exchange material for the second deionisation flow path, a third chamber housing cation exchange material for the first deionising flow path, a fourth chamber being a central concentrating chamber, a fifth chamber housing anion exchange material for the first deionising flow path, a sixth chamber housing anion exchange material for the second deionising flow path, and a final seventh chamber housing a cathode.
- the chambers housing the anode and/or cathode may contain also one or more conducting materials. These may be cation exchange material in the anode chamber and anion exchange material in the cathode chamber.
- the chambers can be separated by relevant perm- selective membranes as known to those skilled in the art. Any piping required for the deionising flow paths between the various exchange materials and/or chambers is also well known in the art .
- a method of providing purified water wherein water to be purified is passed through a first deionising flow path followed by a passage through a second deionising flow path, wherein the outflow from the first path is held in a holding tank prior to passage through the second flow path, and wherein the outflow from the second path is available for use.
- such outflow is partly or fully returned to the holding tank.
- the method of the present invention could use deionisation apparatus as described above, and preferably includes the water in the holding tank being available for use also.
- apparatus for providing a volume of purified water available immediately for use comprising a first deionising flow path for water to be purified through an anion exchange material and/or a cation exchange material, in either order where both materials are used, and an integral second deionising flow path through an anion exchange material and a cation exchange material, in either order, wherein the outflow from the first path is held in a holding tank adapted to hold the volume of purified water, and wherein water in the holding tank is intermittently or continuously circulated through the second flow path and wholly or partly returned to the holding tank.
- the further purity of the outflow from the second deionising flow path which has higher purity than water in the holding tank, inherently maintains or improves the purity of the water in the holding tank when mixed therewith.
- a method of providing a volume of purified water immediately available for use wherein the water to be purified is passed through a first deionising flow path and held in a holding tank from which it is available for use, and wherein water in the holding tank is intermittently or continuously circulated through the second flow path and returned to the holding tank.
- the volume of the water in the holding tank is preferably substantially more than that directly available from the second path outflow over a reasonably short period of time.
- the apparatus of the present invention may be of any suitable size and dimension. The principles of the present invention apply equally to small or large scale apparatus .
- Figure 1 is a schematic cross-sectional side view of apparatus according to the present invention
- Figure 2 is a schematic side view of the stack in Figure 1
- Figure 3 is a graph showing a pilot unit operation of the apparatus in Figure 1.
- Figure 1 shows an electrodeionisation apparatus having a stack (2) and a holding tank (4) .
- the stack (2) has seven chambers.
- the first chamber (5) houses an anode (6) , and preferably contain cation exchange material (7) .
- the second chamber (8) houses a cation exchange material (9) , and is separated from the first chamber (5) by a cation selective membrane (10) .
- Next to the second chamber (8) lies a third chamber (12) housing cation exchange material (13) also.
- the third chamber (12) is separated from the second chamber (8) by a cation exchange membrane (14) .
- Next to the third chamber (12) is a fourth chamber (16) acting as a concentrating chamber for collection and removal of undesired ions. Between the third and fourth chambers (12,16) lies a cation exchange membrane (18) .
- the fourth concentrating chamber may also contain ion exchange material (20) .
- the fourth concentrating chamber (16) is bound on its other side by anion exchange membrane (21) , next to which is a fifth chamber (22) housing anion exchange material (23) .
- a fifth chamber (22) housing anion exchange material (23) .
- a sixth chamber (24) is a fourth chamber (24) , separated by another anion exchange membrane (26) .
- the sixth chamber (24) also houses an anion exchange material (28) .
- the final seventh chamber (30) houses a cathode (32) , and may also house an anion exchange material (34), between which and the sixth chamber (24) is an anion exchange membrane (36) .
- the third and fifth chambers (12,22) may act to provide the first deionising flow path, whilst the second and sixth chambers (8,24) act to provide the second deionising flow path.
- feed water such as from a Reverse Osmosis unit, is fed into the fifth anion exchange material chamber (22) , and subsequently into the third cation exchange material chamber (12) .
- water in the holding tank (4) is drawn (by a pump not shown) into the second deionising flow path formed by the sixth and second chambers of the stack (24,8) .
- the outflow (44) from the second flow path will be of higher quality than water stored in the holding tank (4), and is immediately available for use through a second tap (46) . Where such second outflow (44) is not immediately required, this outflow (44) can be returned to the holding tank (4) .
- the inflow to the tank (4) of such re-purified water will inherently increase or maintain the purity of the water in the holding tank (4) .
- a fluid, generally water, for the flushing streams through the anode chamber (5), the cathode chamber (30) and the concentrating chamber (16) is drawn from the outflow (44) of the second deionising flow path.
- the flushing stream water passes successively through the anode chamber (5) , the cathode chamber (30) and the concentrating chamber (16) .
- the most purified flushing stream water passes countercurrently to the final part of the second deionising flow path through the cation exchange material chamber (8) .
- the flushing stream through the cathode chamber (30) is also arranged to flow countercurrently to the flow through the first deionising flow path anion exchange material in the sixth chamber (24) .
- the apparatus and method of the present invention may be used m combination with any water purification system and/or other water purification apparatus.
- the recirculation of water from the holding tank through the second deionising flow path may be operated continuously m order to maintain the highest possible purity of water in the holding tank. Alternatively, the recirculation may be operated intermittently, in order to maintain the purity of water m the holding tank above a predetermined threshold.
- the flow of water through the first deionising flow path may also be continuous. Preferably, the flow of water through the first deionisation flow path is controllable by one or more volume or level switches m the tank in order to maintain a desired volume in the holding tank without overflow when water is not being drawn off for use.
- the exchange materials in the first deionising flow path will have greater capacity for removing ions from water to be purified as and when required.
- the separation of the first and second flow paths reduces the back pressure ( ⁇ P)of the stack to both flows. This reduction in ⁇ p on the first flow path increases the feed flow and quality when the stack is fed with RO permeate. The reduction in ⁇ P on the second flow path increases the potential flow that is available as output.
- Reverse Osmosis permeate typically has a conductivity of 20 ⁇ S/cm, and the BSI, ASTM and NCCLS laboratory water grades are usually set at 1 and 0.1 ⁇ S/cm.
- the prior art straight-through units can provide water of high purity, eg. less than 0.1 ⁇ S/cm, which could be provided into a tank.
- absorption of any impurities either from the tank or from the environment will reduce the quality of the water significantly, and the conductivity of such water has often been found to be greater than 1 ⁇ S/cm after even a short period of time.
- the water in the tank can be maintained at or below a conductivity of 1 ⁇ S/cm, whilst the dispensed product water available directly from the second outflow has a conductivity of less than 0.1 ⁇ S/cm.
- Figure 3 shows the values of this pilot operation between 660 and 740 hours of running.
- the present invention provides an integral apparatus and method able to supply purified water at a very low conductivity. Purified water at a still significantly low conductivity, and in greater volume, is also available from the holding tank directly.
- the present apparatus requires the use of only a single pair of electrodes and hence one power supply.
- the ion exchange materials in the first deionising flow path can be regenerated when water is not flowing through them such that they have a greater capacity for deionisation when required. such that they have a greater capacity for deionisation when required.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB0100132A GB2355213B (en) | 1999-05-07 | 2000-05-03 | Apparatus and method of recirculating electrodeionisation |
US09/720,350 US6482304B1 (en) | 1999-05-07 | 2000-05-03 | Apparatus and method of recirculating electrodeionization |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB9910550.4A GB9910550D0 (en) | 1999-05-07 | 1999-05-07 | Apparatus and method of recirulating electrodeionisation |
GB9910550.4 | 1999-05-07 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2000067906A1 WO2000067906A1 (en) | 2000-11-16 |
WO2000067906A9 true WO2000067906A9 (en) | 2001-12-27 |
Family
ID=10852974
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2000/011936 WO2000067906A1 (en) | 1999-05-07 | 2000-05-03 | Apparatus and method of recirculating electrodeionisation |
Country Status (2)
Country | Link |
---|---|
GB (2) | GB9910550D0 (en) |
WO (1) | WO2000067906A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100522323C (en) * | 2000-08-11 | 2009-08-05 | 艾奥尼克斯公司 | Device and method for electrodialysis |
DE60202512T2 (en) * | 2001-10-31 | 2005-12-22 | Kurita Water Industries, Ltd. | Device for electrodeionization |
EP1799872A4 (en) | 2004-09-17 | 2008-12-03 | Gekko Sys Pty Ltd | Separation apparatus |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1983003984A1 (en) * | 1982-05-13 | 1983-11-24 | Gerhard Kunz | Method for the treatment of a liquid phase, particularly method for desalting aqueous solutions, as well as device for its implementation |
DE3568946D1 (en) * | 1984-07-09 | 1989-04-27 | Millipore Corp | Improved electrodeionization apparatus and method |
GB2311999B (en) * | 1996-04-12 | 1999-09-08 | Elga Group Services Ltd | Apparatus and method of electrodiaysis |
WO1998051620A1 (en) * | 1997-05-09 | 1998-11-19 | Usf Filtration And Separations Group Inc. | Purification of a liquid stream |
-
1999
- 1999-05-07 GB GBGB9910550.4A patent/GB9910550D0/en not_active Ceased
-
2000
- 2000-05-03 GB GB0100132A patent/GB2355213B/en not_active Expired - Fee Related
- 2000-05-03 WO PCT/US2000/011936 patent/WO2000067906A1/en active Application Filing
Also Published As
Publication number | Publication date |
---|---|
GB0100132D0 (en) | 2001-02-14 |
WO2000067906A1 (en) | 2000-11-16 |
GB9910550D0 (en) | 1999-07-07 |
GB2355213A (en) | 2001-04-18 |
GB2355213B (en) | 2003-01-15 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6482304B1 (en) | Apparatus and method of recirculating electrodeionization | |
US7279083B2 (en) | Electrodeionisation apparatus | |
CA2470633C (en) | Fractional deionization process | |
JP3416455B2 (en) | Electrodeionization method for purifying liquids | |
US5211823A (en) | Process for purifying resins utilizing bipolar interface | |
US6149788A (en) | Method and apparatus for preventing scaling in electrodeionization units | |
JP3244689B2 (en) | Electrodeionization and UV treatment method for purifying water | |
EP2208523B1 (en) | Electrodeionization device with hydrodynamic flow splitting | |
US20070295604A1 (en) | Electrically-driven separation apparatus | |
JPH05209012A (en) | Purified ion-exchange resin and method of its purification | |
US20100133115A1 (en) | Devices and methods for acid and base generation | |
JP2002527238A5 (en) | ||
JP2004033976A (en) | Deionized water manufacturing method and apparatus therefor | |
JP5145305B2 (en) | Electric deionized water production equipment | |
JP6105005B2 (en) | Electric deionized water production apparatus and deionized water production method | |
JP2012239965A (en) | Electric deionized water producing apparatus | |
TWI701218B (en) | Water treatment device and water treatment method | |
JP6627943B2 (en) | Pure water production method | |
WO2000067906A9 (en) | Apparatus and method of recirculating electrodeionisation | |
JP2009297670A (en) | Electric deionized water making apparatus | |
US11542183B2 (en) | Water production for coffee brewing by electrodeionization | |
CN112657339A (en) | Electrodialysis device, electrodialysis system, and method for purifying glycolic acid raw material | |
JP4915843B2 (en) | Electric softening device, softening device and soft water production method | |
WO2022118577A1 (en) | Electric deionized water production apparatus and method for producing deionized water | |
JP2022089407A (en) | Electric type deionized water manufacturing apparatus and deionized water manufacturing method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): GB JP US |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
ENP | Entry into the national phase in: |
Ref country code: GB Ref document number: 200100132 Kind code of ref document: A Format of ref document f/p: F |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 09720350 Country of ref document: US |
|
AK | Designated states |
Kind code of ref document: C2 Designated state(s): GB JP US |
|
AL | Designated countries for regional patents |
Kind code of ref document: C2 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE |
|
COP | Corrected version of pamphlet |
Free format text: PAGE 14, DESCRIPTION, REPLACED BY CORRECT PAGE 14 |
|
122 | Ep: pct application non-entry in european phase | ||
NENP | Non-entry into the national phase in: |
Ref country code: JP |