Patent ID: 7008529

Claim:
A water treating device comprising: a water container for containing water to be treated; an electrolyzing chamber for sterilizing the to-be-treated water by way of electrochemical decomposition by energization of an electrode set consisting of at least two electrode plates; a water treatment line through which the to-be-treated water is introduced into the electrolyzing chamber from the water container and fed back into the water container after the sterilization of the water in the electrolyzing chamber; a residual chlorine sensor for measuring a residual chlorine concentration of the to-be-treated water before the water is introduced into the electrolyzing chamber; and control means for controlling an amount of the to-be-treated water to be subjected to the electrochemical decomposition in the electrolyzing chamber on the basis of the residual chlorine concentration measured by the residual chlorine sensor to keep a residual chlorine concentration of the water to be fed back into the water container within a predetermined range; wherein a bypass line is provided which is branched from the water treatment line at a position upstream of the electrolyzing chamber for sampling the to-be-treated water, introducing the sampled to-be-treated water into the residual chlorine sensor for the measurement of the residual chlorine concentration of the sampled to-be-treated water, and discharging the sampled to-be-treated water into the electrolyzing chamber after the measurement.