Centrifugal pump and axial flow pump start mode

1, centrifugal pump off the pump because the centrifugal pump starts, the pump outlet pipe no water, so there is no pipeline resistance and enhance the high resistance, the pump starts, the pump head is very low, the flow is great, this When the pump motor (shaft power) output great (according to the pump performance curve), it is easy to overload, it will make the pump motor and line damage, so start off the outlet valve in order to make the pump normal operation.
2, the axial flow pump from the pump in the direction of the flow of the pump is along the axis of the impeller inhalation, shaft outflow, so called axial flow pump. Axial pump and centrifugal pump works different, it is mainly the use of high-speed rotation of the impeller generated by the thrust of water. Axial pump leaves the rotation of the water generated by the lift, the water can be pushed from the bottom to the top of the axial flow pump leaves are generally immersed in the pool of water source. As the impeller high-speed rotation, the role of the lift in the leaves, the continuous upward pressure on the water, so that water flows along the outlet pipe. Impeller continuous rotation, the water is also continuous pressure to high, imagine if closed, is bound to cause pressure. In the frequency of the centrifugal pump when the outlet valve is fully open when the flow increases, the resulting mechanical load increases, the frequency of the axial flow pump when the outlet valve is fully open when the flow increases, resulting in reduced mechanical load The When the mechanical load increases, the motor speed will drop, so that the slip rate increases, the rotor current will become larger; the other hand, when the mechanical load decreases, the rotor current will become smaller. Rotor current increases or decreases, but also to cause the stator winding to take the current increase or decrease. So the frequency of operation: centrifugal pump outlet valve fully open when the current will be the largest.