PURPOSE: To prevent entire stop of water in service water facilities even when the tank is poorly fed with water by such a construction that the speed of water delivery pump is selected from three types of control methods in accordance with the water level of the tank.
CONSTITUTION: There are three signals emitted; a water level signal from a level signal transmitter 4, a pressure signal from a pressure transmitter 5, and an operative command signal to take in the flow signal from flow rate transmitter 6 and operate the water delivery pump 3 in accordance with the water level. A control selector block 9 selects the block of control methods in accordance with the water level. An end pressure constant control block 10 controls the water delivery pump 3 so that the discharge pressure at the place of use will become a certain preset end pressure. A stepped end pressure constant control block 11 controls the target discharge pressure so that it drops in accordance with the lowering of water level. A water level constant block 12 controls makes such a control that the water level of the tank 1 will not become lower than the level specified previously.
| JPH09256983 | PREVIOUS STANDBY OPERATION PUMP |
| JP2011157894 | METHOD AND DEVICE FOR PREDICTING CAVITATION EROSION QUANTITY |
HOUSHIYOU TADAYUKI
FUJI KUNIHIKO
