Causes of cavitation in residue pump

The pressure of the residue pump fluid decreases from the inlet of the pump to the inlet of the impeller, and the liquid pressure near the vane is the lowest. The partial pressure of the residual oil pump in operation partially causes the absolute pressure of the pumped liquid to drop to the gasification pressure at the current temperature. The liquid vaporizes at this point, and there may also be gas in the liquid overflowing from the solution. Many bubbles are formed. These bubbles flow forward with the liquid. When the pressure is higher in the leaf, the pressure of the liquid outside the bubble is higher than the pressure inside the bubble. The vaporization pressure of the gas will be reduced sharply and the bubbles will collapse to form cavities. At the same time as the bubbles shrink and break, they will have a large impact pressure, which can reach several hundred atmospheres, form a water hammer, and continuously strike the metal surface. Shock and fatigue peel off. The occurrence of this phenomenon causes the corrosion of the flow-through components, and the above-mentioned process of generating bubbles and bubbles that drastically reduce and even destroy the ruptured flow-through components is the cause of cavitation during the operation of the residue pump.

The pump over-flow part of the residue pump operated under cavitation for a long time will be corroded and destroyed. This is due to the strong impact on the metal surface when the bubbles condense and the metal surface appears pitted. In severe cases, the metal grains are loosened and peeled off. Even in the form of perforations, cavitation is accompanied by the destruction of mechanical forces, as well as a variety of complex forces such as electrolytic chemical corrosion. Practice has shown that radical cavitation must prevent air bubbles in the flow path of the pump during operation.