METHOD FOR OPERATING A WATER SOFTENING ION EXCHANGER SYSTEM WITH REGENERATIVE UNIT BY MEASURING IN SITU THE WATER HARDNESS BY MEANS OF AN ION-SELECTIVE SENSORY MECHANISM AND ARRANGEMENT FOR CARRYING OUT SUCH A METHOD

摘要

The invention relates to a method for operating a water softening-ion exchanger system with regenerative unit by measuring in situ the water hardness by means of an ion-selective sensory mechanism. According to the inventive method, a partial current of the process water which current has a minimized leak rate is branched off. Said branched-off partial current is guided to a sensory mechanism via a controlled valve unit. The control variables for the partial current are determined on the basis of a process signal which in turn is determined by a control unit for the ion exchanger. Said control variables are correlated with the valve units in such a manner that the partial current is adjusted simultaneously with the process water current. The ion-selective sensory mechanism continuously monitors the concentration ratios in the partial current. When defined threshold values are approached or exceeded, the regenerative process of the ion exchanger is initiated. Outside the tapping hours of process water the partial current is interrupted and the sensory mechanism is provided with a calibrating liquid by the valve unit for calibration and control.