Vortex pump is a kind of vane pump. It is mainly composed of impeller, pump body and pump cover. The impeller is a disc, and the blades on the circumference are arranged radially and evenly. A circular flow passage is formed between the pump body and the impeller, and the suction port and the discharge port are all around the outer circle of the impeller. There is a partition between the suction and discharge, which separates the suction and discharge.
We divide the liquid in the pump into two parts: the liquid between the blades and the liquid in the runner. When the impeller rotates, under the action of centrifugal force, the circular velocity of the liquid in the impeller is greater than that in the flow passage, so the "circular flow" shown in Figure 1 is formed. Since the liquid from the suction to the discharge follows the impeller, the combination of the two movements results in the liquid producing the same "longitudinal vortex" as the impeller. So we get the name of vortex pump. It should be noted that the circular velocity of the liquid particle in the flow passage of the pump body is smaller than that of the impeller.
In the process of longitudinal vortex, the liquid particles enter the impeller blades for many times, and transmit the energy to the liquid particles in the flow passage through the impeller blades. Every time a liquid particle passes through a blade, it gains energy. This is also the reason why the head of vortex pump is higher than that of other vane pumps under the same impeller outer diameter. Not all liquid particles pass through the impeller. With the increase of flow, the "annular flow" weakens. When the flow is zero, the "annular flow" is the strongest and the head is the highest. Because the liquid in the flow passage transfers energy through liquid impact. At the same time, it also causes great impact loss, so the efficiency of the vortex pump is relatively low.