Passivation of hollow copper strands in a stator water cooling system

Abstract

A system for passivating a plurality of hollow copper strands in a stator water cooling system including; a first storage tank containing a cleaning solution, a second storage tank containing rinsing water; a third storage tank containing a passivation solution; a plurality of conduits connecting the first, second, and third storage tanks in a closed loop with the plurality of hollow copper strands; and an alkaline pump for pumping the cleaning solution, the rinsing water, and the passivation solution through the closed loop.

What is claimed is: 
     
         1 . A system for passivating a plurality of hollow copper strands in a stator water cooling system, the system comprising:
 a first storage tank containing a cleaning solution;   a second storage tank containing rinsing water;   a third storage tank containing a passivation solution;   a plurality of conduits connecting the first, second, and third storage tanks in a closed loop with the plurality of hollow copper strands; and   an alkaline pump for pumping the cleaning solution, the rinsing water, and the passivation solution through the closed loop.   
     
     
         2 . The system of  claim 1 , further comprising:
 a flow control device for controlling the flow of the cleaning solution, the rinsing water, and the passivation solution through the closed loop; and   a temperature control device for controlling the temperature of the cleaning solution, the rinsing water, and the passivation solution.   
     
     
         3 . The system of  claim 1 , wherein the passivation solution includes one of sodium chlorite solution, sodium hydroxide solution, trisodium phosphate solution, and deionized water. 
     
     
         4 . The system of  claim 1 , wherein the plurality of conduits include polytetrafluoroethylene (PTFE). 
     
     
         5 . The system of  claim 1 , wherein the cleaning solution includes a detergent and water, wherein the ratio of the detergent to the water is about 1 part to about 3 parts. 
     
     
         6 . The system of  claim 1 , further comprising:
 a hot air fan for blowing hot air through the plurality of hollow copper strands.   
     
     
         7 . The system of  claim 1 , further comprising:
 a drainage tank for receiving a discharge from the plurality of hollow copper strands.   
     
     
         8 . A method for passivating at least one hollow copper strand, comprising:
 cleaning an inner surface of the at least one hollow copper strand with a cleaning solution;   rinsing, after the cleaning, the inner surface with a rinsing water; and   passivating, after the rinsing, the inner surface with a passivation solution.   
     
     
         9 . The method of  claim 8 , wherein the cleaning solution includes a detergent and water. 
     
     
         10 . The method of  claim 9 , wherein the ratio of the detergent to the water is about 1 part to about 3 parts. 
     
     
         11 . The method of  claim 8 , wherein the cleaning solution is at a temperature of about 50° C. 
     
     
         12 . The method of  claim 8 , wherein the rinsing water has a temperature of about 50°-70° C. and the rinsing occurs for about 3 minutes. 
     
     
         13 . The method of  claim 8 , wherein the passivation solution includes one of sodium chlorite solution, sodium hydroxide solution, trisodium phosphate solution, and deionized water. 
     
     
         14 . The method of  claim 13 , wherein a temperature of the passivation solution during the passivating is in a range of about 50° C. to about 70° C. 
     
     
         15 . The method of  claim 13 , wherein the passivating is for a period of time of about 2 to about 30 minutes. 
     
     
         16 . The method of  claim 8 , wherein the passivating includes flowing the passivation solution at a flow rate of about 1 cubic foot/second. 
     
     
         17 . A system for passivating at least one hollow copper strand, the system comprising:
 a first storage tank containing a cleaning solution;   a second storage tank containing rinsing water;   a third storage tank containing a passivation solution;   a plurality of conduits connecting the first, second, and third storage tanks in a closed loop with the at least one hollow copper strand; and   an alkaline pump for pumping the cleaning solution, the rinsing water, and the passivation solution through the closed loop.   
     
     
         18 . The system of  claim 17 , further comprising:
 a flow control device for controlling the flow of the cleaning solution, the rinsing water, and the passivation solution through the closed loop; and   a temperature control device for controlling the temperature of the cleaning solution, the rinsing water, and the passivation solution.   
     
     
         19 . The system of  claim 17 , wherein the passivation solution includes one of sodium chlorite solution, sodium hydroxide solution, trisodium phosphate solution, and deionized water. 
     
     
         20 . The system of  claim 17 , wherein the cleaning solution includes a detergent and water, wherein the ratio of the detergent to the water is about 1 part to about 3 parts.