When there is air in the sewage flow centrifugal trash pump casing, the density of the air is much lower than that of the liquid, which produces a smaller centrifugal force. Therefore, the pressure difference between the liquid level of the storage tank and the suction port of the pump is not enough to press the liquid in the storage tank into the pump, that is, the centrifugal pump has no self-priming ability, so that the centrifugal pump cannot deliver the liquid. This phenomenon is called "cavitation phenomenon". ". So how to improve the anti-cavitation performance of sewage flow centrifugal trash pump? What are the tricks?
How to improve the anti-cavitation performance of the sewage flow centrifugal trash pump:
(1) Improve the structural design from the suction port of the centrifugal pump to the vicinity of the impeller. Increase the flow area; increase the radius of curvature of the inlet section of the impeller cover, reduce the rapid acceleration and depressurization of the liquid flow; appropriately reduce the thickness of the blade inlet, and round the blade inlet to make it close to streamline. Reduce the acceleration and depressurization of the head of the flow around the blade; improve the surface finish of the impeller and the blade inlet to reduce the resistance loss; extend the blade inlet to the impeller inlet to make the liquid flow receive work in advance and increase the pressure.
(2) Adopt the front inducer to make the liquid flow work in advance in the front inducer to increase the pressure of the liquid flow.
(3) Double-suction impeller is used to allow liquid flow to enter the impeller at the same time from both sides of the impeller, the inlet section will be doubled, and the inlet flow rate can be reduced by one time.
(4) The design working condition adopts a slightly larger positive angle of attack to increase the blade inlet angle, reduce the bending at the blade inlet, reduce the blade blockage, and increase the inlet area; improve the working conditions under large flow to reduce Flow loss. But the positive angle of attack should not be too large, otherwise the efficiency will be affected.
(5) Use anti-cavitation materials. Practice has shown that the higher the strength, hardness and toughness of the material, the better the chemical stability and the stronger the anti-cavitation performance.