| 摘要 |
PROBLEM TO BE SOLVED: To form a reliable corrosion proof means easily and efficiently by coating the surface of a metal pipe exposed into the atmosphere or touching moisture or corrosive gas and passing a refrigerant of lower temperature on the inside than on the outside with a corrosion proof paint containing a metal salt powder. SOLUTION: A fin tube type heat exchanger has a copper pipe 22 for refrigerant piping passing a refrigerant of lower temperature than the outer air temperature and a large number of aluminum fin plates 21,... are provided on the outer circumference of the copper pipe 22. In order to prevent outer air from touching the aluminum fin 21 and the copper pipe 22 for refrigerant piping to form dews causing corrosion, a corrosion proof film 23 is formed on the surface of the copper pipe 22 by applying a corrosion proof paint uniformly on the entire outer surface of the copper pipe. The corrosion proof paint contains powder material of a metal or a metal salt having a lower polarization potential than the copper pipe material, and a water soluble paint mixed with zinc phosphate is employed, for example. |
