CONTROL OF HARD WATER SCALING IN ELECTROCHEMICAL CELLS

• US 20110168567A1
• Filed: 01/07/2011
• Published: 07/14/2011
• Est. Priority Date: 01/11/2010
• Status: Abandoned Application

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Inventors: Johnson, Jenna M., Kilawee, Patrick H., Olson, Erik C., Smith, Kim R.
• Application Number:
  US12/986,312
• Publication Number:
  US 20110168567A1
• Time in Patent Office: Days
• US Class Current: 205/350
• CPC Class Codes: C02F 1/4674 with halogen or compound of halogens, e.g. chlorine, bromine
• CPC Class Codes: C02F 1/76 with halogens or compounds of halogens C02F1/4674 takes precedence
• CPC Class Codes: C02F 2001/46119 Cleaning the electrodes
• CPC Class Codes: C02F 5/10 using organic substances
• CPC Class Codes: C25B 1/26 Chlorine; Compounds thereof by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34

Abstract

A threshold agent composition and methods of using the same to produce hypochlorite and other effluent streams from an electrochemical cell without the detrimental effects of hard water scaling are disclosed. The invention further discloses use of chemistries to prevent hard water scale formation in various electrochemical cells to enhance cell longevity without decreasing chlorine, hypochlorite or other effluent production.

Claims

1. A method for producing hypochlorite and reducing hard water scaling in an electrochemical cell without decreasing hypochlorite production comprising:

(a) obtaining an electrochemical cell configured with at least one anode and cathode to produce a hypochlorite source;

(b) providing a water and a sodium chloride source to said electrochemical cell;

(c) adding a threshold agent to said electrochemical cell in the amount of up to about 10,000 ppm, wherein said threshold agent is a water soluble polycarboxylate capable of preventing hard water scale formation on electrodes and membranes; and

(d) applying an electric current to the electrochemical cell to produce hypochlorite and reduce hard water scaling in said electrochemical cell, wherein said threshold agent does not decrease said hypochlorite production.

2. The method of claim 1 wherein said threshold agent is a water-insoluble resin.

3. The method of claim 1 wherein said polycarboxylate is selected from the group consisting of homopolymers and copolymers of polyacrylates, polyolefinic systems, polymaleic systems, derivatives and salts of the same, and combinations of the same.

4. The method of claim 3 wherein said polycarboxylate is Acumer 1000.

5. The method of claim 1 wherein said threshold agent is added in the amount of up to about 1,000 ppm and has a molecular weight less than 5,000.

6. The method of claim 1 wherein said threshold agent is added in the amount of from about 50 ppm to about 500 ppm and has a molecular weight less than 2000.

7. The method of claim 1 wherein said hypochlorite effectively cleans and/or sanitizes surfaces without depositing streaks or spotting.

8. A method for reducing hard water scaling in a water source and electrochemical cell producing hypochlorite for a water source without decreasing hypochlorite production comprising:

(a) obtaining a hypochlorite source in a pool, spa or other water source treated with an electrochemical cell;

(b) contacting said hypochlorite source with a threshold agent in the amount of up to about 10,000 ppm, wherein said threshold agent is a water soluble polycarboxylate with a molecular weight less than 5,000; and

(c) reducing hard water scale formation on electrodes and membranes of said electrochemical cell without decreasing hypochlorite production of said electrochemical cell.

9. The method of claim 8 wherein said threshold agent does not deactivate the oxidizing effects of said hypochlorite source in said pool, spa or other water source.

10. The method of claim 8 wherein said threshold agent is a polycarboxylate selected from the group consisting of homopolymers of polyacrylates, copolymers of polyacrylates, derivatives and salts of the same, polyolefinic systems, polymaleic systems and combinations of the same.

11. The method of claim 10 wherein said polycarboxylate is Acumer 1000.

12. The method of claim 8 wherein said threshold agent is added in the amount of up to about 1,000 ppm and has a molecular weight less than 2,000.

13. A method for increasing longevity of an electrochemical cell by reducing hard water scaling comprising:

(a) obtaining an electrochemical cell configured with at least one anode and cathode to produce a hypochlorite source, wherein a water and a sodium chloride source are circulated through said electrochemical cell to produce said hypochlorite;

(b) adding a threshold agent to said electrochemical cell in the amount of up to about 10,000 ppm, wherein said threshold agent is a water soluble polycarboxylate with a molecular weight less than 5,000; and

(c) applying an electric current to the electrochemical cell to produce at least one effluent without causing the precipitation of water hardness ions from the water source and forming hard water scaling.

14. The method of claim 13 wherein said threshold agent is added in the amount of from about 50 ppm to about 5,000 ppm.

15. The method of claim 13 wherein said sodium chloride source is brine.

16. The method of claim 13 wherein said polycarboxylate is selected from the group consisting of homopolymers of polyacrylates, copolymers of polyacrylates, derivatives and salts of the same, polyolefinic systems, polymaleic systems and combinations of the same.

17. The method of claim 16 wherein said polycarboxylate is Acumer 1000.

18. The method of claim 13 wherein said threshold agent is added in the amount of up to about 1,000 ppm and has a molecular weight less than 2,000.

19. The method of claim 18 wherein said threshold agent is added in the amount of from about 50 ppm to about 500 ppm.