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A corrosion-resistant, copper-finned heat exchanger for a water heater is provided. The heat exchanger includes a conduit through which water runs, heat-transfer fins extending from the conduit and an anti-corrosive coating containing electroless nickel. The heat-transfer fins contain copper, and th

A corrosion-resistant, copper-finned heat exchanger for a water heater is provided. The heat exchanger includes a conduit through which water runs, heat-transfer fins extending from the conduit and an anti-corrosive coating containing electroless nickel. The heat-transfer fins contain copper, and the coating is deposited directly onto at least one of the copper heat-transfer fins.

대표청구항 ▼

1. A method of preventing corrosion of a copper heat exchanger for a water heater, the method comprising:immersing a copper heat exchanger into an aqueous-chemical-deposition bath comprising at least one of nickel, cobalt, palladium, platinum and combinations thereof; andelectroless-chemically depos

1. A method of preventing corrosion of a copper heat exchanger for a water heater, the method comprising:immersing a copper heat exchanger into an aqueous-chemical-deposition bath comprising at least one of nickel, cobalt, palladium, platinum and combinations thereof; andelectroless-chemically depositing an electroless coating comprising at least one of nickel, cobalt, palladium, platinum and combinations thereof onto at least a portion of the heat exchanger, whereby the electroless coating substantially prevents corrosion of the heat exchanger when the heat exchanger is used in conjunction with a functioning water heater. 2. The method of claim 1, wherein the electroless coating is about 0.05 mils to about 10 mils in thickness. 3. The method of claim 2, wherein the electro less coating is about 0.1 mils to about 1.5 mils in thickness. 4. The method of claim 3, wherein the electroless coating is about 0.25 to about 1.0 mils in thickness. 5. The method of claim 1, wherein the chemical-deposition bath further comprises phosphorus. 6. The method of claim 5, wherein the electroless coating comprises an electroless nickel-phosphorus network. 7. The method of claim 6, wherein the heat exchanger is a copper-coiled heat exchanger having heat-transfer fins, the heat-transfer fins having the electroless coating applied thereon. 8. The method of claim 7, wherein the electroless nickel-phosphorus network comprises about 0.01 to about 16 percent phosphorus. 9. The method of claim 8, wherein the electroless nickel-phosphorus network comprises about 6 to about 9 percent phosphorus. 10. The method of claim 1, wherein the chemical-deposition bath further comprises sodium hypophosphite, an acid, a boron derivative and water. 11. The method of claim 10, wherein the bath comprises about 20 to about 100 parts of nickel per liter of solution, about 10 to 40 parts of sodium hypophosphite per liter of solution, and about 20 to about 40 parts of acid per liter of solution. 12. The method of claim 11, wherein the bath comprises about 80 to about 90 parts of nickel per liter of solution, about 15 to about 20 parts of sodium hypophosphite per liter of solution and about 25 to about 35 parts of acid per liter of solution. 13. The method of claim 1, whereby no electrical current is used during at least three quarters of the chemical deposition process. 14. The method of claim 1, whereby an electrical current is used initially after the heat exchanger is immersed in the bath, but for no more than thirty seconds. 15. The method of claim 1, whereby the electroless coating can withstand high temperatures associated with products of combustion. 16. The method of claim 1, wherein the electroless coating comprises nickel, boron or phosphorus and at least one other metal selected from the group consisting of cobalt, iron, tungsten and molybdenum. 17. A method of manufacturing a water heater, the method comprising:electroless-chemically depositing an electroless coating onto a portion of a coiled copper heat exchanger, the heat exchanger having a conduit through which water runs and heat-transfer fins extending therefrom; andpositioning the heat exchanger into a housing, the housing having a flue positioned above a combustor therein, wherein the coating substantially inhibits corrosion of the exchanger. 18. The method of claim 17, wherein the coating comprises at least one of nickel, cobalt, palladium, platinum and combinations thereof. 19. The method of claim 18, wherein the coating comprises at least one of nickel and a compound thereof. 20. A method of inhibiting corrosion of a coiled copper heat exchanger for a water heater, the method comprising:immersing at least a portion of the coiled copper heat exchanger into an aqueous-chemical-deposition bath comprising at least one of nickel, cobalt, palladium, platinum and combinations thereof; andelectroless-chemically depositing an electroless coating onto at least a portion of the heat exchanger,wherein no electri cal current is applied during the majority of the electroless-chemical deposition, the coating comprises at least one of nickel, cobalt, palladium, platinum and combinations thereof, and the coating substantially inhibits corrosion of the heat exchanger when the heat exchanger is used in conjunction with a functioning water heater. 21. The method of claim 1, wherein the heat exchanger includes heat-transfer fins having an outer surface, and the coating is deposited on the outer surface of at least one fin. 22. The method of claim 21, wherein a plurality of the fins are crimped, and have the coating thereon. 23. The method of claim 17, wherein the coating is deposited on at least one heat-transfer fin. 24. The method of claim 23, wherein a plurality of the fins are crimped, and have the coating thereon. 25. The method of claim 20, wherein the heat exchanger includes heat-transfer fins having an outer surface, and the coating is deposited on the outer surface of at least one fin. 26. The method of claim 25, wherein a plurality of the fins are crimped, and have the coating thereon. 27. A method of improving the functioning of a heat exchanger for a water heater, the method comprising:crimping a plurality of heat-transfer fins on a copper heat exchanger to form crimped fins for improving heating efficiency of the heat exchanger; andelectroless-chemically depositing an electroless coating onto a plurality of the crimped fins, the coating comprising at least one of nickel, cobalt, palladium, platinum and combinations thereof.