Corrosion in a Water Cooling System

Flow measurements showed flow rates lower than expected and backwashing was observed. The backwash contained brownish siliceous matter and other solid impurities. All three heat exchangers had silt and dirt deposits and partially plugged tubes. The tube ends were corroded and thinned down. Perforation of the tubes originated from inside (cooling water side). Pitting shows it to be underdeposit corrosion. 

A commercial cooling water program during start-up and stabilization of the cooling tower after major repairs is likely to avoid the adverse results. The water quality should be maintained. 

Sampathkumar and A.N. Screeram - International Congress, Gloccorr 2002, National Corrosion Council of India. 

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All three types may be present in heat exchangers. Any object such as loose scale or other deposits resting on a metal surface can give rise to a concentration cell and hence to crevice corrosion, which is reported to be the most potentially damaging type of corrosion in a water cooling system. Corrosion products can nucleate crystallization from supersaturated solutions or subcooled melts, anchor... 

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