Causes of Cavitation in Vacuum Units

Cavitation in vacuum units can seriously shorten equipment life and prevent normal operation. Long-term loaded operation, high cooling water temperature in summer, insufficient cooling water flow or poor heat exchange can make a water ring vacuum pump operate near its limit at high vacuum. Under these conditions, water inside the pump may approach boiling, generating bubbles whose formation and collapse can damage the impeller, disturb dynamic balance, cause strong vibration and damage auxiliary equipment.

To address cavitation, reducing water temperature or lowering the vacuum level by increasing condenser back pressure may not be practical because it affects unit load capacity. A better option is often to install an atmospheric ejector on the water ring vacuum pump unit. This helps maintain condenser vacuum while keeping the internal vacuum at a level that avoids steam corrosion. When cavitation occurs, causes should be identified first and the solution should be matched to the operating condition.