OPERATING METHOD OF VERTICAL SHAFT PUMP DRIVEN BY ENGINE

摘要

PURPOSE:To eliminate bad influence upon an engine by discharging the air in a vertical shaft pump while in no-load running or stopping, raising the water level in the vertical shaft pump up to the level where the pump can raise water by itself, letting it perform no-discharge operation applying actual loads on it, and then stopping the engine. CONSTITUTION:The following no-discharge operation is performed by a vertical shaft pump after continuous air-flow operation, that is, no-load operation in the state of water level A where the suction port of a suction cylinder 2 stays underwater. That is, first of all, a delivery valve 6 is completely closed, and a suction valve 10 and discharge valve 11 are also fully opened to operate the vacuum pump 9 installed between the valves 10 and 11. In addition, the air between the water face of a water level A and the delivery valve 6 is discharged out of the vertical shaft pump through a discharge pipe 8 to raise the water level. As a result, when the water level B reaches the specified level 1a of a pump casing 1, water is made to enter the discharge pipe 8, and a flow sensor 12 detects. In the next step, the vacuum pump 9 is made to stop, and then an engine is made to stop after no-discharge operation with the pump loaded.