Biofouling And Corrosion Research For Marine Heat Exchangers

Experimental research on biofouling and corrosion of heat-exchange materials in warm and cold seawater was carried out between 1977 and 1987 for the US Department of Energy's Ocean Thermal Energy Conversion (OTEC) program. Major findings include the following: (1) there is negligible biofouling from deep (600 m) seawater; (2) biofouling from warm surface seawater can be controlled by intermittent chlorination at environmentally acceptable levels; (3) the uniform rate of corrosion for aluminum is acceptable in both warm and cold seawater with no pitting observed in warm seawater; (4) some aluminum alloys show good resistance to pitting in cold seawater; and (5) the use of claddings and other protective measures does not now appear to be cost effective. From these and other experiments, we conclude that marine heat exchangers need not be designed for cleaning by mechanical methods, and that aluminum-based materials can be considered for marine applications. 3 refs., 8 figs.