Patent DE-102010061179-A1 (DE)
Title: Arrangement useful for producing drinking water of selected hardness, comprises ion exchanger, inlet for connecting to drinking water supply, outlet for providing the drinking water of selected hardness, and mixing valve
Inventor: HECKING WILLI
IPC: C02F1/42
Filed: 2010-12-13
Abstract: Arrangement (10) for producing drinking water of selected hardness, comprises: (i) an ion exchanger; (ii) an inlet (14) for connecting to a drinking water supply and an outlet (16) for providing the drinking water of selected hardness; (iii) a mixing valve (24) connected to an ion exchanger outlet for mixing a drinking water treated in the ion exchanger with untreated drinking water from the drinking water supply; and (iv) a setting means (54) for setting a mixing ratio of treated and untreated drinking water for achieving the required hardness; (v) a cavity; and (vi) a piston. Arrangement (10) for producing drinking water of selected hardness, comprises: (i) an ion exchanger; (ii) an inlet (14) for connecting to a drinking water supply and an outlet (16) for providing the drinking water of selected hardness; (iii) a mixing valve (24) connected to an ion exchanger outlet for mixing the drinking water treated in the ion exchanger with untreated drinking water from a drinking water supply; and (iv) a setting means (54) for setting a mixing ratio of treated and untreated drinking water for achieving the required hardness; (v) a cavity, which is formed by the mixing valve and is connection with the ion exchanger inlet, the ion exchanger outlet, the inlet and the outlet; and (vi) a piston with openings arranged between a maintenance position and an end position movable in the cavity. The openings are arranged so that a direct connection from the inlet is present in the maintenance position through the piston to the outlet and the piston closes the ion exchanger inlet and a connection from the inlet to the ion exchanger inlet and a connection from the ion exchanger outlet to the outlet are present in the end position. An intermediate position between the maintenance position and the end position are adjustable, in which both the connection from the inlet to the outlet, a connection from the inlet to the ion exchanger inlet and from the ion exchanger inlet to the outlet are present, and the mixing ratio is adjustable over the flow cross-sections of the connection. An independent claim is also included for producing drinking water of selected hardness by the ion exchanger and the mixing valve for mixing the drinking water treated in the ion exchanger with untreated drinking water from the drinking water supply, comprising (a) determining the water hardness of the untreated drinking water by titration or other method of high accuracy, (b) determining the conductivity of the untreated drinking water with a conductivity sensor, (c) passing the entire drinking water flow through the ion exchanger and determining the conductivity of the treated drinking water with the conductivity sensor, (d) generating a calibration curve from the so determined measurements for the water hardness and the conductivity under the assumption that the water hardness of the treated drinking water is less than 1 German hardness degree, preferably 0, and (e) adjusting mixing ratio required for selected hardness with the mixing valve by controlling conductivity set-point at the outlet of the mixing valve corresponding to the selected hardness.