Abstract:
This paper discusses a case history of corrosion of aluminum fins installed around copper tubes used in industrial air conditioners. The corrosion occurred preferentially in the regions of air circulation causing the powdering of the aluminum fins. The observed corrosion is unusual since, under normal operating conditions, the passivation of both the aluminum fins and of the copper tubes is expected, with negligible corrosion rates of both metals. However, the severe attack of the aluminum fins was observed in a period that varied from 3 to 4 years. The inspected air conditioners were installed in continuous electroplating facilities which use acids, particularly hydrochloric, sulfuric and chromic. Based on the corrosion product and the cooling water analyses, an explanation is presented aiming at clarifying the corrosion mechanisms.
Reference:
PANOSSIAN, Z.; TANAKA, D.K. Corrosão de aletas de refrigeração do aparelho condicionador de ar em atmosferas poluídas. Corrosão e Proteção, v. 2, n. 7 p. 42-45, set./out. 1978.
This paper discusses a case history of corrosion of aluminum fins installed around copper tubes used in industrial air conditioners. The corrosion occurred preferentially in the regions of air circulation causing the powdering of the aluminum fins. The observed corrosion is unusual since, under normal operating conditions, the passivation of both the aluminum fins and of the copper tubes is expected, with negligible corrosion rates of both metals. However, the severe attack of the aluminum fins was observed in a period that varied from 3 to 4 years. The inspected air conditioners were installed in continuous electroplating facilities which use acids, particularly hydrochloric, sulfuric and chromic. Based on the corrosion product and the cooling water analyses, an explanation is presented aiming at clarifying the corrosion mechanisms.
Reference:
PANOSSIAN, Z.; TANAKA, D.K. Corrosão de aletas de refrigeração do aparelho condicionador de ar em atmosferas poluídas. Corrosão e Proteção, v. 2, n. 7 p. 42-45, set./out. 1978.
