Difference in service performance between axial flow pump and centrifugal pump

Francis pump from the shape and structure are between the centrifugal pump and the axial flow pump; Francis pump pumping principle, the impeller high-speed rotation, both centrifugal force centrifugal pump, but also with axial pump push force, mixed-flow pump rely on this A mixture of two forces pumping water. Mixed-flow pump performance is also between the centrifugal pump and axial pump, centrifugal pump and it compared to the lower head, while the larger flow; it compared with the axial flow pump, head higher, but the flow is smaller. This is a vast area for our country, terrain complex, more than a pump type selected according to local conditions. The performance of mixed-flow pumps is expressed in terms of operating parameters. Such as flow, lift, power, efficiency, speed and so on. In a certain speed, the flow as a variable, that is, if you change the flow of the pump, the pump head, power and efficiency are all changes. The relationship between these changes in the law, drawn together into several curves to represent, this is the pump performance curve. Mixed-flow pump performance curve shape is also between the centrifugal pump and axial pump, for high-lift mixed-flow pump, the flow and lift, flow and power changes in the law close to the centrifugal pump, in use, the valve can be closed Start, when the power is the smallest, power machine safety. For the low-head mixed-flow pump, the variation law between the performance parameters is close to the axial flow pump. In use, the valve should not be used to start the valve, but should start the valve when the power is relatively small, the motor is not easily burned. In view of the above characteristics, mixed flow pump for irrigation and drainage in the hilly areas.