Since the direction of the suction pipe and the outlet pipe is affected by the rotation direction of the stainless steel multi-stage centrifugal pump, it is important to understand the definition of the rotation direction. The stainless steel multistage centrifugal pump centrifugal lift is constant for a given impeller diameter and flow, and the lift head is a function of flow. At some point on the head flow curve, once the lift head exceeds the centrifugal head, then at these points Pressure gradient reverse, resulting in the opposite direction of flow, that is, the phenomenon of reflow.
The mechanism of the inlet return of the impeller with low specific speed centrifugal pump is analyzed from the theoretical and experimental aspects. It is considered that the rotational speed component is the main reason for the inlet return of the impeller, and it is pointed out that the return flow is the main reason leading to the instability of the small flow. As the design staff in the design of low-speed high-speed induction wheel stainless steel multi-stage centrifugal pump is often used positive angle method, in order to ensure that the induction wheel produced stainless steel multi-stage centrifugal pump head to meet the energy requirements of centrifugal wheel imports, The inlet angle is greater than the liquid flow angle, and the centrifugal wheel is given better cavitation performance, and the blade inlet angle is larger than the liquid flow angle. In order to obtain high efficiency, in the design of ultra low specific speed high speed induction wheel centrifugal pump When the actual flow angle is smaller than the flow angle under the design conditions, so that the induction wheel and the centrifugal wheel inlet front has a non-uniform peripheral velocity component, Thereby producing a vortex around the flow line.
Therefore, the inlet return of the stainless steel multistage centrifugal pump induction wheel and the centrifugal wheel is actually caused by the uneven velocity of the liquid flow at the edge of the rotating blade, which is a vortex that involves the vortex and the vortex around the axis flow.