| 摘要 |
PURPOSE:To improve the corrosion resistance by coating the inner surface with a surface treatment agent comprising paint to form an organic film added by at least one kind among benzotriazole, tolyltriazole and mercaptobenzothiazole. CONSTITUTION:The heat exchanger having two rows of tubes, each row consisting of 32 tubes of 10mm inner diameter X 300mm long X 1.2mm thick tube made of brass, total of 64 tubes, is degreased and is the entire inner surface is coated as follows. First, acrylmelamine clear paint is added by 5wt% of benzotriazole, and further is thinned by a mixture of methanol, aceton and toluene. Its solid constituent part is adjusted to 10%, and surface treatment agent is added to the tank 10. Such paint is introduced into the heat exchanger (0) for 5min at a rate of 10l/min in the direction of arrow A by a pump 11. Then, the drying air at 150 deg.C is drawn for drying and baking for 20min at a rate of 10l/min in the direction of arrow B by a drying air supplying device 13 to coat the inner surface of the heat exchanger (0) with the acrylmelamine film having the average thickness of 1mum. |
