Diagnosis of impeller faults in a centrifugal pump based on spectrum analysis of vibration signals

Centrifugal pumps are widely used in many critical applications. To ensure the safety and high performance of pump operations vibration techniques are generally used for condition monitoring. However it has noticed that less research has paid to developing monitoring approaches to the faults on impellers which is core part and subject to constant erosions. This paper focus on the studies of vibration responses to the incipient van tip faults on impellers and developing corresponding features to detect and diagnose this faults. It has found that the spectral components from flow turbulence are predominant in the high frequency range above 1 kHz, which are shown less changes due to defects on the exit tip of impellers. On the other hand the discrete components caused by the interaction of flow, impeller and casing show more definitive changes due to the defects. In particular the amplitudes at vane passing frequency and the higher order harmonics at shaft frequency can be effective features for the detection and diagnosis of the fault severity.