METHOD AND APPARATUS FOR MANAGING WATER TREATMENT CHEMICAL INJECTION OF OPEN CIRCULATING COOLING WATER SYSTEM

PROBLEM TO BE SOLVED: To provide a method and apparatus for managing water treatment chemical injection of an open circulating cooling water system which can inject a water treatment chemical by a simple method so as to maintain the concentration of the chemical in circulating water at a constant level even in a water system where the water quality of make-up water changes.SOLUTION: In order to prevent corrosion by circulating cooling water and generation of scale, slime and the like, the water treatment chemical is injected to a make-up water passage 6 through a chemical tank 12, a chemical pump 13, and a chemical injection passage 14. The amount of the chemical corresponding to the ratio of the amount of the make-up water to the electric conductivity of the make-up water is added to a predetermined amount of the make-up water so as to keep the electric conductivity of the circulating water at a constant level and maintain the concentration of the chemical in the circulating water at a constant level.