The Study of Using the Inducer to Improve the Cavitation Performance of a Centrifugal Pump

Abstract To improve the cavitation performance of a single-stage, single-suction centrifugal pump, this study compared the effects of an equal-pitch inducer and a variable-pitch inducer. Experimental results revealed that the NPSH 3 of the pump without an inducer is 4.6m for operation at Q=80m 3 /h, while with an equal-pitch inducer and a variable-pitch inducer are respectively 2.6m and 2.2m. Both two inducers significantly increase the shut-off heads, while the BEP shift towards smaller flow rates, with the maximum efficiency value reduced by about 3%. The CFD simulation analysis show that when the inlet total pressure is greater than 4m, the equal-pitch inducer has better anti-cavitation performance, while the variable-pitch angle inducer has a better inhibitory effect on cavitation development which the inlet total pressure is less than 4m. To further enhance the pump’s cavitation performance, filing blade inlet suction side of the variable-pitchinducer is necessary to reduce the NPSH 3 from 2.2m to 1.7m, resulting in a 22% improvement in cavitation performance.