Patent ID: 6152689
Filing Date: 2000-11-28
Classification: F04D,F05B

Abstract:
A self-priming centrifugal pump comprising:a main pump unit for pumping a liquid;an auxiliary pump unit for centrifugal gas-liquid separation; andan exhaust vacuum device;wherein a region in the vicinity of a central part of an impeller included in the main pump unit is connected via a passage having a small passage area as compared with a discharge ability of the auxiliary pump unit to a suction opening of the auxiliary pump unit, a delivery opening of the auxiliary pump unit is connected via a return passage to the suction opening of the main pump unit, a region in the vicinity of a central part of an impeller included in the auxiliary pump unit is connected via an exhaust passage to the vacuum device, and said exhaust passage includes in series therein a slow-acting valve which opens with a delay after connection of a prime mover for driving the self-priming centrifugal pump to a power source, and a quick-acting valve which closes immediately after disconnection of the prime mover from the power source.