PURPOSE: To sterilize water containing ammoniacal nitrogen to be recirculated and reused without generating a chlorine smell, an irritant smell, the damage of the hair of a water user and the pain of an eye and a throat while preventing the generation of scale and improving the handling properties of a sterilizing agent.
CONSTITUTION: A saline solution is electrolized in a diaphragm free electrolytic cell 15 to form sodium hypochlorite 40 which is, in turn, injected in circulating pool water 21 by a pump 31 and piping 30. The concn. of free residual chlorine in the pool water 21 is measured by a sensor 34 and the injection of sodium hypochlorite due to the pump 31 is controlled so that the measured concn. is received in a predetermined range.
NAKAMURA SHIGEOKI
MATSUMOTO AKIHIKO
