| 摘要 |
PROBLEM TO BE SOLVED: To provide a water quality control method of circulating cooling water by which a phosphoric acid component in recycled water can be utilized for corrosion prevention of water system members and scale deposition in the water system can be also suppressed.SOLUTION: In a water quality control method of circulating cooling water that uses phosphoric acid-containing recycled water at least as a part of makeup water, concentration is controlled so that phosphoric acid concentration in the cooling water may be 20 to 25 mg PO/L, 10 to 20 mg/L of a scale prevention polymer is added and pH of the cooling water is controlled between 7.0 and 7.5, calcium hardness in the cooling water is made to be 1,500 mg CaCO/L or less, Clconcentration is made to be 2,500 mg/L or less and SOconcentration is made to be 2,500 mg/L or less. |
