The swirl impeller is all or part of the impeller is retracted to the flow channel of the pressure chamber, and has good anti-clogging performance. The particles flow in the water pressure chamber is driven by the eddy current generated by the rotation of the impeller. The movement of the suspended particles does not generate energy, and the flow channel exchanges energy with the liquid. In the flow process, suspended particles or long fibers do not contact with the worn blades, and the blades are slightly worn, and there is no increase in clearance due to abrasion, which is suitable for pumping media containing large particles and long fibers.

The blades of centrifugal pump impeller are generally backward curved blades. There are two types of blades: cylindrical and twisted. The application of twisted blades can reduce the load of blades, improve the suction performance of centrifugal pumps and improve the cavitation resistance, but it is difficult to manufacture and the cost is high. The impeller of centrifugal pump for oil refining and chemical industry is required to be cast or welded as an integral pump impeller. The welded pump impeller is developed in recent years and is mainly used for special centrifugal pumps for chemical industry made of metal materials with poor casting performance, such as iron and its alloys. The geometric accuracy and surface finish of the welded pump impeller are better than that of the cast impeller, which is conducive to improving the efficiency of the centrifugal pump.