Mixed-flow pumps can be divided into volute-type mixed-flow pumps and guide vane-type mixed-flow pumps in terms of structure. There are two types of volute mixed-flow pumps, horizontal and vertical. At present, the horizontal type is widely produced and used, and the vertical type is mostly used for large pumps. The structure of the volute mixed-flow pump is similar to the single-stage single-suction centrifugal pump. The shape and structure of the guide vane mixed flow pump is similar to that of the axial flow pump, and it is divided into two types: horizontal and vertical.
From the appearance and structure, the mixed flow pump is between the centrifugal pump and the axial flow pump. The liquid in the mixed-flow pump flows out of the impeller obliquely, that is, the direction of the liquid flow relative to the impeller has both radial speed and axial speed. Compared with centrifugal pumps, the performance of mixed-flow pumps has a lower head and a higher flow rate; compared with axial flow pumps, a higher head and lower flow rate. The performance curve shape of the mixed flow pump is also between the centrifugal pump and the axial flow pump. For the high-head mixed flow pump, the change law of the relationship between flow and head, flow and power is close to that of the centrifugal pump. In use, the valve can be closed. start up. For low-head mixed-flow pumps, the change rule between performance parameters is close to that of axial flow pumps. It is not advisable to start with closed valves in use, but should start with open valves. At this time, the power is relatively small and the motor is not easily burned.