In open type wraparound cooling water system in the corrosion suppression mannered

摘要

PROBLEM TO BE SOLVED: To provide an excellent method for suppressing the metal corrosion without incorporating environmental contaminants such as heavy metals and phosphorus and without producing scale in an open type circulating water cooling system where the concentration degree of a cooling tower is increased, and the concentration of silica is high.;SOLUTION: The metal corrosion in an open type circulating cooling water system is suppressed by adding a water soluble maleic acid polymer whose extinction coefficient at 190 nm is 0.09 to 0.2 mg^-1dm³cm^-1 and/or a water soluble salt thereof to circulating water controlled so that the concentration of silica reaches 70 to 300 (mg/L), and the corrected Ryznar index including a correction term of silica concentration shown by the formula: RI'=RI-0.004×[SiO₂] (mg/L)(wherein, RI is the Ryznar index at 40°C, and [SiO₂] (mg/L) is the silica concentration in the circulated water) falls in a range of 3.0 to 6.0 by increasing the concentration degree of a cooling tower.;COPYRIGHT: (C)2004,JPO