ABSTRACT
This chapter discusses the root causes of impeller induced cavitation surging are identified and a strategy which will secure acceptable pump operation. Cavitation surging in a centrifugal pump is a thermodynamic process with boundaries controlled by hydrodynamic flow patterns. Cavities grow only where low-pressure regions exist in which the pressure is below vapour pressure. The onset and intensity of cavitation surging is primarily determined by the shape of the impeller blades at inlet. The extent to which cavities travel away from the impeller is determined by inlet pipe geometry. Impeller design induced cavitation surging arises from the propensity of centrifugal pump impellers to generate a backflow. The pressure fluctuations in the inlet and outlet pipe and the simultaneously observed plant vibrations indicate that the pump is experiencing the effects of large changes in momentum. The force produced can challenge the integrity of axial thrust bearings.
