Reasonable Selection of Shaft Body of Axial Flow Pump

Reasonable Selection of Guide Vane of Axial Flow Pump

The effect of the axial flow pump guide vanes is to eliminate the velocity of the flow from the impeller outlet, convert the kinetic energy of the circumferential velocity of the flow into pressure energy, and use the diffusion action to convert the kinetic energy of the partial axis velocity into pressure energy. For this reason, it is necessary to set a certain number of guide vanes in the guide vanes of the axial flow pump, but in the axial flow guide vane design, the number of vanes is selected according to the number of revolutions. The recommended number of guide leaves Zg-5 a Lu, or Zg-5 ~ 10, high specific speed axial pump to take a small value, and the requirements of the blade and the impeller of the best number of leaves each other prime number. Due to the relatively large range of the axial flow pump, the majority of the number of guide vanes are taken as the lowest value in the calculation, especially for the high specific speed axial flow pump, but the diffusion between the adjacent vanes angle. , We will find that the diffusion angle is too small. If the flow rate is not properly selected, or if the liquid flow enters the cascade of the guide vane, the pressure increment obtained by the deceleration of the flow between the adjacent two vanes is not significant. According to the literature (2) (3) It is pointed out that when the pressure increment obtained when the liquid flows through the guide vanes can not compensate for the loss of frictional resistance when the liquid flows between adjacent vanes, the number of vanes or The conical diffuser is used instead of the vane. To this end, from the conditions to meet a certain diffusion angle, for the axial flow pump than the number of applications, the number of reasonable control of the number of guide leaves. In this way, on the one hand, it is possible to achieve a sufficient energy conversion of the flow in the guide vanes while minimizing the loss of hydraulic frictional resistance in the vanes