軸流泵在污水處理廠污泥回流泵房或氧化溝工藝的使用過程中，會出現(xiàn)工作一段時間后電流緩慢爬升的現(xiàn)象，導(dǎo)致設(shè)備不能正常使用。軸流泵可以在理想流體即清水中正常使用，但在黏性流體即污水中使用時，由于葉輪對流體的黏度反應(yīng)比較靈敏，使得葉輪的水力性能具有突變性，對水力效率和軸功率產(chǎn)生影響；加上黏性流動具有很大的旋性和旋渦的擴散性，增加了汽蝕發(fā)生的可能性，也降低了水泵效率，使電機負(fù)載產(chǎn)生變化，運行電流緩慢爬升。為了提高水泵的抗汽蝕性能，在保證符合設(shè)計工況各項性能參數(shù)的前提下，通過適當(dāng)降低nD 值，選擇高汽蝕比轉(zhuǎn)速模型，使得改造后的水泵運行更加穩(wěn)定，有效延長水泵水力部件的使用壽命，也有效拓寬了軸流泵的使用范圍。

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.