| 摘要 |
PURPOSE:To produce the titled heat-transfer pipe having a rugged metallic plated layer on the inner wall surface by introducing a plating soln. added with an oxyethylene surfactant and low-concn. chloride ions into the heat- transfer pipe along with bubbles and carrying out plating. CONSTITUTION:A heat-transfer pipe 10 firmly attached with a radiating fin 3 is held above a plating bath 7. A plating soln. 9 is circulated through the inside of the heat-transfer pipe 10 by a connecting pipe 11 and a circulating pump 12, the plating soln. 9 is simultaneously dripped into the plating bath 7 and generated bubbles are sent into the heat-transfer pipe 10. About 0.6mol/l CuSO4 and about 0.5mol/l H2SO4 are incorporated into the plating soln. 9 and about 0.33X10<-3>mol/l HCl and about 19mg/l polyoxyethylene oleyl ether are further added to the soln. Under such conditions, the heat-transfer pipe 10 and a counter electrode 14 having a spacer 16 are connected to a DC electric power source 13 through a connecting terminal 15 and an electric current is passed. Consequently, a rugged copper-plated layer having excellent hardness and adhesion is formed on the inner wall surface of the heat-transfer pipe 10 and the heat-transfer area is increased. |
