Self-balancing multi-stage pump guide vanes The function of the self-balancing multi-stage pump guide vanes is to convert the kinetic energy transmitted by the impeller to the liquid into pressure energy. It does not generate a lift, so it should minimize the hydraulic loss. The vanes designed according to the constant velocity method are the best. Only the kinetic energy in the diffuser behind the throat of the vane can be converted into pressure energy. The pump efficiency is highest when using a diffuser with a total diffusion angle in the range of 7-13. Even the best diffuser can't end the conversion of kinetic energy, as evidenced by a large hydraulic model. The experiment found that the pressure was highest at 7 times the diameter of the outlet flange.
The hydraulic performance of the vanes depends on the following design elements:
1) Base circle diameter It is related to the diameter of the impeller.
2) Angle of the tongue The angle of the tongue is selected according to the absolute flow angle at the outlet of the impeller, but for the medium to low specific speed pump, the angle of the tongue is allowed to be different from the absolute flow angle.
3) The flow area of the volute allows the flow area of the volute to gradually expand from the tongue toward the throat to accommodate the flow from the impeller
