DETECTION OF EXCHANGE PERIOD FOR WATER-SOFTENING MATERIAL IN HARD WATER SOFTENER

摘要

PURPOSE:To properly detect the exchange period of ion-exchange resin, by applying high-frequency voltage to water, to be softened, at the upperstream point of an ion-exchange filter and at its downstream point apart in a fixed distance from the upperstream point through two different kinds of electrodes located inside a vessel. CONSTITUTION:When crude water is fed through an inflow pipe 3 and a net- shaped filter 13 into the filter vessel 2 of a hard water softener 1, the crude water is fed from the net-shaped filter 13 through a drain pipe 4 to a faucet or the like under the condition that the crude water is softened by ion-exchange resin 12 in the filter vessel 2. Under this water-flowing condition, the water flowing through the filter vessel 2 and the resin are handled as electrolytes, and the change of electric resistance generated by the conversion of the resin from a type-Na into a type-Ca is utilized as the difference of electric resistance to be generated between two couples of electrodes comprising reference electrodes 7 and indicating electrodes 8 in the resin-water system. The resistance difference is inputted into a detector 11 through an electric wire 10 connected to each of the electrodes 7, 8.