Tomographic investigations on the effects of gas entrainment on centrifugal pumps

High-resolution gamma-ray computed tomography (HireCT) was applied to clarify the two phase flow distribution inside the impeller wheel of a running pump. Thus, the accumulated gas holdup inside the impeller of an industrial centrifugal pump was investigated and analysed, depending on the suction side gas volume fraction and type of two phase flow regime. Using time-averaging rotation-synchronized tomographic imaging technique, effects on the conveying performance of the centrifugal pump could be clarified. The obtained results contributes to a better understanding of the flow behavior and its effects inside the impeller of a centrifugal pump, which is running under two phase flow conditions due to gas entrainment. Moreover, the results can help to develop improved pump designs to avoid loss of conveying performance due to gas entrainment.