Electrodialysis membrane and gasket stack system

• US 20010037942A1
• Filed: 05/31/2001
• Published: 11/08/2001
• Est. Priority Date: 04/28/2000
• Status: Active Grant

• Current Assignee: EET Corporation
• Original Assignee: EET Corporation
• Inventors: Schmidt, James, Schmidt, Ernst, Schmidt, Erich, Schmidt, Brian M., Williams, Michael E.
• Granted Patent: US 6,537,436 B2
• Time in Patent Office: Days
• US Class Current: 204/634
• CPC Class Codes: B01D 61/44 Ion-selective electrodialysis
• CPC Class Codes: B01D 61/50 Stacks of the plate-and-frame type
• CPC Class Codes: Y02A 20/124 Water desalination

Abstract

An apparatus and system of operation of an electrodialysis membrane and gasket stack for separation of components in liquid mixtures is disclosed. The system of operation for purification and deionizing liquids includes an operation of pretreatment by filtration for removal of inorganic contaminants, includes an operation of adsorption for removing organic contaminants by activated carbon adsorption, and includes an operation of deionizing for removing ions from the effluent liquids. The deionizing operation includes an apparatus having an electrodialysis stack of a plurality of ion exchange membranes and separating gaskets for selectively removing contaminant ions. The electrodialysis stack of ion exchange membranes and separating gaskets provides continuous operations for purifying ethylene glycol and glycol/water mixtures, for continuous desalinating of water, and/or for continuous deionizing of water to generate ultra-pure water or other purified liquid mixtures. The combination of treatment operations and the deionizing operation provides a continuous operating system with minimized down-time and improved efficiencies over prior methods for purification of liquid mixtures.

Claims

1. A membrane cell stack for purification of liquid mixtures having contaminants dispersed therein, and for deionization of liquid mixtures by passage through the membrane cell stack, the liquid mixtures including concentrate liquids and/or dilute liquids, said membrane cell stack comprising:

an electrodialysis cell stack including a plurality of disparate layers being stacked together, said electrodialysis cell stack having a first end and a second end, said plurality of disparate layers being disposed contiguous and having a first outer layer at said first end, and a second outer layer at said second end;

a support frame having a first outer end proximate said first end of said cell stack, and having a second outer end proximate said second end, with said plurality of disparate layers interdisposed therebetween said first outer end and said second outer end;

at least two electrodialysis gaskets including a first electrodialysis gasket being positioned at said first outer end, and a second electrodialysis gasket being positioned at said second outer end;

a cathode electrode plate being positioned proximate and interior of said first electrodialysis gasket being positioned at said first outer end;

at least one anode electrode plate being positioned proximate and interior of said second electrodialysis gasket being positioned at said second outer layer;

at least two membrane gaskets including a first membrane gasket being positioned proximate and interior of said cathode electrode plate, and a second membrane gasket being positioned proximate and interior of said anode electrode plate, said first membrane gasket and said second membrane gasket having a central opening therethrough and having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

said plurality of disparate layers including;

an anion membrane having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

at least one electrodialysis membrane gasket having a central opening therethrough and having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

at least one turbulence promoter layer being sized to fit proximate said opening within said at least one electrodialysis membrane gasket and having a plurality of holes through each opposed end for passage of liquid mixtures therethrough; and

a cation membrane having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

whereby said plurality of disparate layers being repeated in series, the liquid mixtures being passed through said plurality of holes in respective disparate layers of said electrodialysis cell stack; and

connecting means for connection of said plurality of disparate layers within said support frame;

whereby said electrodialysis cell stack including said plurality of disparate layers being repeated as required for purification and deionization of the liquid mixtures being passed therethrough.

2. The membrane cell stack of

claim 1

, wherein said electrodialysis cell stack further comprises a voltage generating means for application of an electrical voltage differential between said cathode electrode plate and said at least one anode electrode plate, said voltage generating means including a voltage generator, said electrodialysis cell stack having a first electrode in contact with said cathode electrode plate, and a second electrode in contact with said at least one anode electrode plate.

3. The membrane cell stack of

claim 1

, wherein said plurality of disparate layers being stacked adjacent and having a plurality of shapes being sized for being positioned within said support frame, said plurality of disparate layers further includes a plurality of turbulence promoter plates and a plurality of electrodialysis membrane gaskets being positioned between said anion membrane and said cation membrane for direction of the waste liquids from the plurality of holes through each opposed end of each disparate layer to the plurality of holes through each adjacent disparate layer for passage of liquid mixtures therethrough said electrodialysis cell stack.

4. The membrane cell stack of

claim 1

, wherein said first electrodialysis gasket and said second electrodialysis gasket being composed of ethylene propylene diene monomer of about 0.031 inch thickness.

5. The membrane cell stack of

claim 1

, wherein said first membrane gasket and said second membrane gasket being composed of ethylene propylene diene monomer of about 0.062 inch thickness.

6. The membrane cell stack of

claim 1

, wherein said at least one turbulence promoter being composed of polypropylene fabric of about 0.030 inch thickness.

7. The membrane cell stack of

claim 1

, wherein said at least one electrodialysis membrane gasket having an opening therethrough being composed of ethylene propylene diene monomer of about 0.031 inch thickness.

8. The membrane cell stack of

claim 1

, wherein said first end of said electrodialysis cell stack comprising a first input valve and a second input valve through said first end for receipt of concentrate liquids in said first input valve, and for receipt of dilute liquids in said second input valve, whereby said concentrate liquids and said dilute liquids being passed though said plurality of disparate layers of said electrodialysis cell stack.

9. The membrane cell stack of

claim 8

, wherein said second end of said electrodialysis cell stack comprising a first output valve and a second output valve through said second end for passage of concentrate liquids out of said second output valve, and for passage of dilute liquids out of said first output valve, whereby said concentrate liquids and said dilute liquids having passed though said plurality of disparate layers of said electrodialysis cell stack.

10. The membrane cell stack of

claim 9

, wherein said support frame having a first outer end and having a second outer end, further comprises:

at least one intake valve in said first outer end;

an electrolyte liquid being input into said at least one intake valve, said electrolyte liquid being in contact across said cathode electrode plate;

said electrolyte liquid being in contact across said anode electrode plate; and

at least one exit valve in said second outer end for removal of said electrolyte liquid from said cell stack;

whereby said electrolyte liquid does not contact said concentrate liquids or said dilute liquids within said cell stack.

11. A membrane cell stack for purification of liquid mixtures having contaminants dispersed therein in concentrate liquids and/or in dilute liquids, and for deionization of liquid mixtures by passage through said membrane cell stack comprising:

an electrodialysis cell stack including a plurality of disparate layers being stacked together, said electrodialysis cell stack having a first end and a second end, said plurality of disparate layers being disposed contiguous and having a first outer layer at said first end, and a second outer layer at said second end;

a support frame having a first outer end proximate said first end of said cell stack, and having a second outer end proximate said second end, with said plurality of disparate layers interdisposed therebetween said first outer end and said second outer end;

at least two electrodialysis gaskets including a first electrodialysis gasket being positioned at said first outer end, and a second electrodialysis gasket being positioned at said second outer end;

a cathode electrode plate being positioned proximate and interior of said first electrodialysis gasket being positioned at said first outer end;

at least one anode electrode plate being positioned proximate and interior of said second electrodialysis gasket being positioned at said second outer layer;

at least two membrane gaskets including a first membrane gasket being positioned proximate and interior of said cathode electrode plate, and a second membrane gasket being positioned proximate and interior of said anode electrode plate, said first membrane gasket and said second membrane gasket having a central opening therethrough and having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

said plurality of disparate layers including;

an anion membrane having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

a first electrodialysis membrane gasket having a central opening therethrough and having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

a first turbulence promoter layer being sized to fit proximate said opening within said first electrodialysis membrane gasket;

a cation membrane having a plurality of holes through each opposed end for passage of liquid mixtures therethrough;

a second electrodialysis membrane gasket having an opening therethrough and having a plurality of holes through each opposed end for passage of liquid mixtures therethrough; and

a second turbulence promoter layer being sized to fit proximate said opening within said second electrodialysis membrane gasket;

whereby said plurality of disparate layers being repeated in series, the liquid mixtures being passed through said electrodialysis cell stack;

connecting means for connection of said plurality of disparate layers within said support frame; and

a voltage being supplied by a voltage supply means, said voltage being applied as a voltage differential between said cathode electrode plate and said anode electrode plate;

whereby said electrodialysis cell stack including said plurality of disparate layers being repeated as required for purification and deionization of the liquid mixtures being passed therethrough.

12. The membrane cell stack of

claim 11

, wherein said electrodialysis cell stack further comprises a first electrode in contact with said cathode electrode plate, and a second electrode in contact with said at least one anode electrode plate for application of said voltage differential between said cathode electrode plate and said at least one anode electrode plate.

13. The membrane cell stack of

claim 12

, wherein said plurality of disparate layers being substantially parallel and being sized and shaped for being positioned within said support frame, said plurality of disparate layers further includes a plurality of turbulence promoter plates being positioned between said anion membrane and proximate said anode electrode plate.

14. The membrane cell stack of

claim 13

, wherein said first electrodialysis gasket and said second electrodialysis gasket being composed of ethylene propylene diene monomer of about 0.031 inch thickness.

15. The membrane cell stack of

claim 14

, wherein said first membrane gasket and said second membrane gasket being composed of ethylene propylene diene monomer of about 0.062 inch thickness.

16. The membrane cell stack of

claim 15

, wherein said turbulence promoter being composed of polypropylene fabric of about 0.030 inch thickness.

17. The membrane cell stack of

claim 16

, wherein said first electrodialysis membrane gasket and second electrodialysis membrane gasket being composed of ethylene propylene diene monomer of about 0.031 inch thickness.

18. A system for electrodialysis treatment of liquid mixtures including concentrate liquids and/or dilute liquids comprising the operations of:

providing a pretreating operation for filtration of inorganic contaminants and organic contaminants, said pretreatment operation generating a filtrate effluent;

providing an adsorbing operation for adsorbing organic contaminants from said filtrate effluent utilizing activated carbon adsorption, said adsorbing operation generating a liquid fraction; and

providing a deionizing operation for continuous purifying of said liquid fraction from said adsorbing operation, including utilizing an electrodialysis stack having a plurality of membranes and separating gaskets, said deionizing operation selectively removing contaminant ions from said liquid fraction;

whereby said deionizing operation providing said electrodialysis stack having a plurality of ion exchange membranes providing continuous purifying of said liquid fractions of ethylene glycol and glycol/water mixtures, and providing continuous purifying of water, and/or continuous purifying ethylene glycol and/or glycol and water mixtures.

19. The system for electrodialysis treatment of

claim 18

, wherein said deionization operation comprises:

providing an electrodialysis cell stack including a plurality of disparate layers being stacked together, said electrodialysis cell stack having a first end and a second end, said plurality of disparate layers being disposed contiguous and having a first outer layer at said first end, and a second outer layer at said second end;

supporting said electrodialysis cell stack within a support frame having a first outer end proximate said first end of said cell stack, and having a second outer end proximate said second end, with said plurality of disparate layers interdisposed therebetween said first outer end and said second outer end;

providing at least two electrodialysis gaskets including a first electrodialysis gasket being positioned at said first outer end, and a second electrodialysis gasket being positioned at said second outer end;

positioning a cathode electrode plate proximate and interior of said first electrodialysis gasket being positioned at said first outer end;

positioning an anode electrode plate proximate and interior of said second electrodialysis gasket being positioned at said second outer layer;

providing at least two membrane gaskets including a first membrane gasket being positioned proximate and interior of said cathode electrode plate, and a second membrane gasket being positioned proximate and interior of said anode electrode plate, said first membrane gasket and said second membrane gasket having an opening therethrough;

positioning said plurality of disparate layers in series including;

an anion membrane;

at least one electrodialysis membrane gasket having an opening therethrough;

at least one turbulence promoter layer being sized to fit proximate said opening within said at least one electrodialysis membrane gasket; and

a cation membrane;

whereby said positioning said plurality of disparate layers being repeated in series;

passing the liquid mixtures through said electrodialysis cell stack; and

supplying a voltage differential between said cathode electrode plate and said anode electrode plate;

whereby said deionizing operation purifies and deionizes the liquid mixtures being passed therethrough.