Electrodeionization electrode chamber configuration for enhancing hardness tolerance
AssigneeGeneral Electric Company
InventorJohn H. Barber
Life of this patent
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Abstract
An electrodeionization stack for deionizing a feed solution. The electrodeionization stack includes a recirculating system adapted to flow an acidic anode effluent solution into a cathode compartment. The anode compartment, may have a three-layer ion exchange resin stack, the three-layer ion exchange resin stack being made up of a layer of cation exchange resin, a layer of anion exchange resin, and a mixed bed ion-exchange resin located between the cation and the anion exchange resins. The cathode compartment may have anion exchange resins adjacent the cathode and a mixed bed ion exchange resins.
Claims19
An electrodeionization stack for deionizing a feed solution, the electrodeionization stack comprising:
- a cathode and an anode;
- a first ion exchange membrane;
- a second ion exchange membrane;
- a salt concentrating compartment and a deionizing compartment between the first and second ion exchange membranes;
- an ion exchange resin located in the deionizing compartment;
- a cathode compartment between the first ion exchange membrane and the cathode, the cathode compartment adapted to accept a cathode feed solution and dispense a cathode effluent solution;
- an anode compartment between the second ion exchange membrane and the anode, the anode compartment adapted to accept an anode feed solution and dispense an acidic anode effluent solution;
- a transfer system adapted to flow acidic anode effluent solution into the cathode feed solution;
- the deionizing compartment adapted to accept the feed solution and dispense a deionized effluent on application of an applied electric potential difference.
A method of producing a deionized effluent from a feed solution which comprises anions and cations, the method comprising:
- providing the feed solution to a deionizing compartment of an electrodeionizing stack, the electrodeionizing stack comprising an anode and a cathode;
- providing an anode feed solution to an anode compartment of the electrodeionizing stack;
- providing a cathode feed solution to a cathode compartment of the electrodeionizing stack;
- applying an electric potential difference across the electrodeionizing stack to:
- (i) induce the cations in the feed solution to move through a first ion exchange membrane towards the cathode, and induce the anions in the feed solution to move through a second ion exchange membrane towards the anode, thereby producing the deionized effluent;
- and
- (ii) generate H+ ions in the anode compartment;
- dispensing the deionized effluent from the deionizing compartment;
- dispensing an anode effluent solution from the anode compartment;
- and
- transferring at least a portion of the anode effluent solution into the electrodeionizing stack as the cathode feed solution, or as a mixture with the cathode feed solution.
Dependencies are inferred from the claim text.