How To Improve The Anti Cavitation Performance Of Centrifugal Pumps?

Dec 07, 2024

What is' cavitation '? When there is air inside the centrifugal pump casing, a smaller centrifugal force is generated due to the much lower density of air compared to liquid. Therefore, the pressure difference between the liquid level above the storage tank and the pump suction port is not sufficient to press the liquid in the storage tank into the pump, that is, the centrifugal pump has no self-priming ability, which makes the centrifugal pump unable to transport liquid. This phenomenon is called "cavitation phenomenon". So how to improve the anti cavitation performance of centrifugal pumps? What are the tricks?

(1) Improve the structural design of the suction port of the centrifugal pump to the vicinity of the impeller. Increase the overcurrent area; Increase the curvature radius of the inlet section of the impeller cover plate to reduce the rapid acceleration and pressure drop of the liquid flow; Appropriately reducing the thickness of the blade inlet and rounding it to a streamline shape can also reduce the acceleration and pressure drop around the blade head; Improve the surface smoothness of the impeller and blade inlet to reduce resistance loss; Extend the blade inlet edge towards the impeller inlet to allow the liquid flow to receive work in advance and increase pressure.

(2) By using a front induction wheel, the liquid flow can perform work in advance in the front induction wheel to increase the liquid flow pressure.

(3) By using a double suction impeller, the liquid flow enters the impeller from both sides simultaneously, doubling the inlet cross-section and reducing the inlet flow velocity.

(4) The design condition adopts a slightly larger positive angle of attack to increase the blade inlet angle, reduce the bending at the blade inlet, reduce blade blockage, and increase the inlet area; Improve working conditions under high flow conditions to reduce flow losses. But the positive angle of attack should not be too large, otherwise it will affect efficiency.

(5) Use materials that are resistant to cavitation. Practice has shown that the higher the strength, hardness, and toughness of a material, the better its chemical stability, and the stronger its resistance to cavitation.