Data and illustrations are presented from a field study in which test coupons of six commercial aluminum compositions were immersed in circulating waters in operating cooling towers in New York, Philadelphia and Washington where corrosion has been a troublesome operating problem. Serious pitting of the aluminum occurred with untreated and improperly treated circulating waters. With correct and controlled water treatment, no appreciable corrosion of the aluminum took place.
On the basis of this study and observations of aluminum cooling towers in service, recommendations are offered for the design and operation of cooling towers made of aluminum. These include selection of the construction materials with a view toward corrosion resistance as well as physical properties, design to avoid corrosion promoting conditions, painting for protection of particularly sensitive portions of the equipment, good housekeeping and the continuous application of adequate corrosion inhibiting chemicals to the circulating water.
