In essence, the phenomenon of centrifugal pump air erosion is a kind of void mechanics, which is related to vortex. It refers to the pressure of fluids to its critical pressure (usually saturated steam pressure) during the motion, and vaporization of fluids in the local area occur in local and places to generate tiny empty bubbles. After the development of the air bubble group increased to a certain degree, the impact of external factors (gas dissolving, steam condensation, etc.) disappeared and disappeared. The water hammer effect was caused in a local area, and its stress could reach thousands of atmospheric pressure. Obviously, this role is destructive. From the perspective of macro results, the phenomenon of air erosion causes the surface of the flow tract to be damaged (a continuous high -frequency strike destruction), which causes vibration and noise; The flow channel is obstructed, causing a decline in the performance of the pump.

It can be seen from the above statement that the phenomenon of air erosion is caused by the minimum absolute pressure in the flow field. The absolute pressure is small, and the air erosion is prone to occur. Therefore, controlling minimum absolute pressure can control the empty effect and effectively reduce the occurrence of air erosion.

The pump is a machine that increases energy to the fluid. The fluid flows outward through the impeller, and its pressure is generally increased. Therefore, the minimum pressure appearing in the pump can only be near the import of the impeller. In this way, to ensure that the fluid has sufficient absolute pressure at the import of the impeller, it has become the key to avoiding air erosion in the pump.