APPARATUS AND METHOD FOR CONTROLLING INJECTION OF CARBONATE IN WATER TREATMENT INSTALLATION

摘要

PROBLEM TO BE SOLVED: To control the injection of carbonate in a water treatment installation with high accuracy at a low running cost. SOLUTION: A pH meter 5 for measuring the pH of water to be treated in a reaction tank l and a sodium carbonate injection pump 7 for injecting sodium carbonate in the reaction tank 1 from a sodium carbonate storage tank 8 are arranged to the reaction tank 1. The measured value of the pH meter 5 is inputted to an injection control device 6 to be converted to an electric signal which is, in turn, outputted to the sodium carbonate injection pump 7 to control the injection amount of sodium carbonate. The optimum value of the pH in the reaction tank 1 is preset to the injection amount control device 6 and the sodium carbonate injection pump 7 is controlled so that the pH in the reaction tank 1 approaches the optimum value.