18-28: Novel Galvanized Cooling Tower Corrosion Inhibitor

Galvanized coatings for cooling tower systems have been used since the 1950s.  The galvanizing process binds a layer of zinc to steel and serves as a sacrificial anode to prevent corrosion of the underlying steel structure.  However, galvanized cooling towers that have not been properly treated at start-up may experience rapid formation of a soft, white, fluffy, non-protective zinc-corrosion product known as “white rust”.  Consequently, the corrosion of the underlying steel can become concentrated under the white rust bumps, quickly develop into pitting corrosion and if left unchecked, leads to leaks in the system.  This study presents a novel passivation procedure and new chemistry for galvanized systems.  The procedure is free of white rust and calcium phosphate scale formation.