叶轮切割技术在磁力离心泵中的应用

Application of Impeller Cutting Technology to Magnetic Centrifugal Pump

离心泵使用过程中,由于泵选型不当或工艺发生改变,导致泵的扬程偏大,扬程富余太多,泵出口阀门开度非常小,节流损失大,排量受到限制,造成工况不稳,调节困难。为使泵满足现场工艺要求,可采用切割叶轮的方法进行调整。离心泵采用切割叶轮的方法,可以改变泵的性能参数,解决泵的匹配性。通过分析低比转数离心泵叶轮切割指数,采用切割指数与比转数曲线拟合的方法计算叶轮切割参数,结果与实际吻合较好。适当减小叶轮外径,在转速不变的条件下降低泵的流量、扬程和功率,提高泵的比转数,改变泵的性能参数,有效避免了磁力离心泵轴承和磁钢的损坏,确保安全运行。

Improper centrifugal pump type or variable processes will possibly result in its high lift.If pump has too high lift and too small outlet valve opening,throttling loss will be large and output volume will be limited,which will result in unsteady working conditions and difficult adjustment.In order to make centrifugal pump meet field process requirements,impeller cutting technology may be used to adjust its performance parameters and improve its adaptability.Analyzed are impeller cutting indexes of centrifugal pump with low specific speed,calculated are its impeller cutting parameters by using the method of cutting indexes fitted with specific speed curves and calculation results are basically consistent with actual situation.Proper decrease of impeller outer diameter,reduction of pump flow,lift and power with invariable rotate speed,increase of specific speed and improvement of performance parameters can effectively avoid damage on bearings and steel magnet in magnetic centrifugal pump and assure its safe operation.