METHOD FOR PLATING INNER WALL OF HEAT EXCHANGER TUBE

摘要

PURPOSE:To easily and efficiently form an uneven metallic layer by plating on the surface of the inner wall of a heat exchanger tube by changing the voltage of a DC power source to the positive side. CONSTITUTION:A heat exchanger tube 10 and heat radiating fins 3 are temporarily fixed at prescribed positions and the tube 10 is expanded to press-bond the tube 10 and the fine 3 together. The tube 10 is then combined with a connecting pipe 11 and a circulating pump 12, and a plating soln. 9 in a plating tank 7 is circulated through the inside of the tube 10. The plating soln. 9 is a copper sulfate soln. contg. an oxyethylene surfactant and low concn. chloride ions as additives. Positive charge is applied to a counter electrode 14 as the anode from a DC power source 13 and negative charge to one connection terminal 15 as the cathode. Thus, as uneven metallic layer is formed by plating on the surface of the inner wall of the heat exchanger tube 10.