污水处理厂轴流泵电流爬升的原因及解决方法

轴流泵在污水处理厂污泥回流泵房或氧化沟工艺的使用过程中，会出现工作一段时间后电流缓慢爬升的现象，导致设备不能正常使用。轴流泵可以在理想流体即清水中正常使用，但在黏性流体即污水中使用时，由于叶轮对流体的黏度反应比较灵敏，使得叶轮的水力性能具有突变性，对水力效率和轴功率产生影响；加上黏性流动具有很大的旋性和旋涡的扩散性，增加了汽蚀发生的可能性，也降低了水泵效率，使电机负载产生变化，运行电流缓慢爬升。为了提高水泵的抗汽蚀性能，在保证符合设计工况各项性能参数的前提下，通过适当降低nD 值，选择高汽蚀比转速模型，使得改造后的水泵运行更加稳定，有效延长水泵水力部件的使用寿命，也有效拓宽了轴流泵的使用范围。

When axial flow pumps are used in sludge reflux pump house of wastewater treatment plants or oxidation ditch process, the current will climb slowly after a period of operation and then the pumps can’t be used normally. The axial flow pump can be used normally in ideal fluid (clean water), but its hydraulic efficiency and shaft power are affected when used in viscous fluids (wastewater), because the impeller is sensitive to fluid viscosity and the hydraulic performance of impeller is mutable. In addition, the viscous flow has great rotation and vortex dispersion, which increases cavitation possibility and reduces pump efficiency, so that the motor load changes and the running current slowly climbs. In order to improve the cavitation resistance of the pump, under the premise of ensuring the performance parameters of the design condition, the high cavitation ratio speed model is selected by appropriately lowing the nD value to make the transformed pump run more stable, effectively extend the service life of the hydraulic components of the pump, and effectively expand the use range of the axial flow pump.