| 摘要 |
PURPOSE:To vary the quantity of fluid injected by a quantitative pump per unit flow rate of a main fluid without changing the flow rate characteristics of the quantitative pump, by setting variably the control signal of said pump which is extracted from a flow rate detection output shaft of a rotary flow rate meter. CONSTITUTION:A rotary flow rate meter 12 is connected to a part of a water supply system 10, and a switch mechanism 14 unified to the meter 12 forms an electric control system of a quantitative pump 12. The detection signal obtained from the mechanism 14 is sent to a controller 18, and the controller 18 transmits the prescribed driving signal to a control part 20 of the pump 16 in response to the detection signal of the mechanism 14. In such a way, the pump 16 which is driven under control by the mechanism 14 sucks a chemical liquid through a sucking pipe 26 led out of a prescribed chemical liquid storage tank 24 and supplies the chemical liquid of a fixed quantity to the water service system 10 via an ejection pipe 28. |
