86-18: Advances in Deposit Control For Cooling Water Systems

The deposition of suspended solids in once-through and recirculating cooling water systems can have adverse impact on heat exchangers and condensers in industrial and power generating plants. This paper reviews the chemistry of dispersion and the current methods and products for controlling deposition and presents data confirming the improved performance observed with recently developed polymer chemistry. The relationship of pH, temperature, water quality, and polymer dosage-and their effects on the dispersion of colloidal silt and iron oxide particles-are discussed. The measured zeta potential, (i.e., charge modification behavior) for various dispersants is correlated to performance in light transmittance lab tests. Field case studies are presented discussing the application of newly developed polymers to prevent deposition under actual operating conditions.