Control of the Suction Recirculation Flow to Reduce the Cavitation in Centrifugal Impellers

The present study investigates the results of a research regarding the control of the suction recirculation flow, in the aim to reduce the cavitation in centrifugal pumps. The analyse starts from the cavitation coefficient, its connection with the centrifugal pump inlet cavitation reserve, NPSH, correlated with the operating parameters and the impeller geometry. The study shown that the impeller geometry and angle β1 influence the cavitation coefficient and net positive suction head of the pump. The recirculation flow rate in suction was established and was found that for Q <; 0.56 QBEP the cavitation become strong. NPSH (Q) curves with and without recirculation were plotted, their intersection is at NPSH = 2.45 m.