EP0170895B1
Expired / Lapsed
EP
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Improved electrodeionization apparatus and method
Assignee: EMD Millipore Corp
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Filing: 1985-07-05
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Granted: 1989-03-22
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Expires: 2005-07-05
Abstract
No abstract record available.
Inventors
- 👤 Anthony J. Giuffrida
- 👤 Anil D. Jha
- 👤 Gary C. Ganzi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:29
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/46; C02F1/469; C02F1/4693; C02F1/4695; B; B01; B01D; B01D61/00; B01D61/42; B01D61/44; B01D61/46; B01D61/48; B01J; B01J47/00; B01J47/02; B01J47/06; B01J47/08; C02F1/42; C02F1/4604; C02F2201/00; C02F2201/46; C02F2201/461; C02F2201/46105; C02F2201/46115; C02F2201/4612; C02F2201/46125; C02F2201/4613; C02F2209/00; C02F2209/05
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
267 words
An electrodeionization apparatus adapted to remove ions from a liquid which comprises: a cathode compartment at a first end of said apparatus, an anode compartment at an end of said apparatus opposite said first end, a plurality of alternating ion depletion compartments and ion concentration compartments positioned between said cathode compartment and said anode compartment, each of said concentration compartments being free of ion exchange solid composition, means for passing a first liquid to be purified through said ion depletion compartments, means for passing a second liquid for accepting ions from said first liquid, through said concentration compartments, means for applying an electrical voltage between an anode in said anode compartment and a cathode in said cathode compartment and means for recovering purified liquid from said depletion compartment, characterized in that each of said ion depletion compartments comprises a spacer having a hollow central portion divided by a plurality of ribs extending along the length of each of said ion depletion compartment to define a plurality of subcompartments, each of said subcompartments containing an ion exchange solid composition, which is retained in the subcompartments by bonding an ion permeable membrane and a cation permeable membrane to the spacer and to each of said ribs, along the length of said ribs, on opposite surfaces with respect to the spacer, each of said subcompartments having a width defined by the distance between said ribs of between 0.762 and 10.16 cm and a thickness between 0.127 and 0.635 cm, wherein the thickness of said subcompartments is defined by the distance between the anion permeable membrane and the cation permeable membrane.
Claim 2
Dependent Claim
267 words
An electrodeionization apparatus adapted to remove ions from a liquid which comprises: a cathode compartment at a first end of said apparatus, an anode compartment at an end of said apparatus opposite said first end, a plurality of alternating ion depletion compartments and ion concentration compartments positioned between said cathode compartment and said anode compartment, each of said concentration compartments being free of ion exchange solid composition, means for passing a first liquid to be purified through said ion depletion compartments, means for passing a second liquid for accepting ions from said first liquid, through said concentration compartments, means for applying an electrical voltage between an anode in said anode compartment and a cathode in said cathode compartment and means for recovering purified liquid from said depletion compartment, characterized in that each of said ion depletion compartments comprises a spacer having a hollow central portion divided by a plurality of ribs extending along the length of each of said ion depletion compartment to define a plurality of subcompartments, each of said subcompartments containing an ion exchange solid composition, which is retained in the subcompartments by bonding an ion permeable membrane and a cation permeable membrane to the spacer and to each of said ribs, along the length of said ribs, on opposite surfaces with respect to the spacer, each of said subcompartments having a width defined by the distance between said ribs of between 0.762 and 10.16 cm and a thickness between 0.127 and 0.635 cm, wherein the thickness of said subcompartments is defined by the distance between the anion permeable membrane and the cation permeable membrane.
Claim 3
Dependent Claim
17 words
The apparatus of claim 1 wherein the width of said subcompartment is between 1.27 and 3.81 cm.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1 wherein the thickness of said subcompartment is between 0.152 and 0.317 cm.
Claim 5
Independent Claim
26 words
The apparatus of any one of claims 1, 2 or 3 which includes means in said concentration compartments for effecting turbulent flow of said second liquid.
Claim 6
Independent Claim
55 words
The apparatus of any one of claims 1, 2 or 3 wherein the ion exchange composition comprises a mixture of anion exchange resin beads and cation exchange resin beads and wherein the volume ratio of anion exchange resin beads to cation exchange resin beads in said ion depletion compartments is between about 2.0 and 0.5.
Claim 7
Dependent Claim
99 words
The apparatus according to claims 1 to 5 comprising a plurality of stages, each built up of the compartments and means defined by claim 1, the plurality of alternating ion depletion compartments and ion concentration compartments defining a first stage, the means for recovering purified liquid from ion depletion compartments being located in a final downstream stage, the apparatus additionally comprising: means for transferring purified liquid from the depletion compartments of the first stage to a next downstream stage and means for transferring said second liquid from the concentration compartments of the first stage to an adjacent downstream stage.
Claim 8
Dependent Claim
63 words
A process for removing ions from a liquid by means of the apparatus of claims 1 to 5, characterized by passing the first liquid to be purified through the depletion compartments, passing the second liquid adapted to accept ions through said concentration compartments, passing an electrolyte through each of said anode and cathode compartments and recovering purified liquid from said ion depletion compartments.
Claim 9
Dependent Claim
36 words
The process of claim 7 wherein the apparatus is according to claim 5 and the volume ratio of anion exchange resin beads to cation exchange resin beads is controlled to be between about 1.75 and 1.25.
Claim 10
Dependent Claim
40 words
The process of any of claims 7 or 8 wherein the voltage between a cell pair defined by an anion permeable membrane, a depletion cell, a cation permeable membrane and a concentration cell is between about 0.5 and 2 volts.
Claim 11
Dependent Claim
29 words
The process of any of claims 7 or 8 wherein the flow velocity of liquid through said ion depletion compartments is between about 25,40cc/min/ cm width and 762cc/min/cm width.
Claim 12
Dependent Claim
70 words
The process of claims 7 to 10 wherein a first liquid to be purified is sequentially passed through the depletion compartments in each stage of the apparatus of claim 6, characterized by passing a second liquid adapted to accept ions through the concentration compartments in each stage, passing an electrolyte through each of said anode and cathode compartments in each stage and recovering purified liquid from the ion depletion compartments.
Claim 13
Dependent Claim
30 words
The process of any one of claims 7, 8 or 11 wherein the first liquid is treated in a preliminary step to remove ions and organics from said first liquid.
Claim 14
Dependent Claim
44 words
The process of any of claims 7, 8 or 11 wherein the first liquid is treated in a preliminary step with an ion exchange resin to remove ions from said first liquid and with a scavenger resin to remove foulants from said first liquid.
Claim 15
Dependent Claim
52 words
The process of any one of claims 7, 8 or 11 wherein the electrodeionization apparatus is backwashed periodically by introducing cleansing liquid into the apparatus of claim 1 into a normally used liquid outlet of each depletion compartment and removing said cleansing liquid from a normally used inlet of each depletion compartment.
Claim 16
Dependent Claim
47 words
The process of any one of claims 7, 8 or 11 wherein the liquid to be purified is an aqueous liquid and the voltage in the electrodeionization apparatus is controlled to polarize water in the depletion compartments thereby to effect hydrogen ion transfer into the concentration compartments.
References Cited (Backward Citations)
No citation records indexed.
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