A vortex pump (also called a vortex pump) is an impeller pump. It is mainly composed of impeller, pump body and pump cover. The impeller is a disc, and the blades on the circumference are evenly arranged radially. An annular flow channel is formed between the pump body and the impeller, and the suction port and the discharge port are both on the outer circumference of the impeller. There is a partition between the suction port and the discharge port, thereby separating the suction port and the discharge port.

The liquid in the pump is divided into two parts: the liquid between the blades and the liquid in the flow channel. When the impeller rotates, under the action of centrifugal force, the circumferential speed of the liquid in the impeller is greater than the circumferential speed of the liquid in the flow channel, so the "circular flow" shown in Figure 1 is formed. Since the liquid from the suction port to the discharge port follows the impeller, the combined result of these two movements causes the liquid to produce the same "longitudinal vortex" as the impeller turns. Hence the name of the vortex pump. It needs to be pointed out that the circumferential velocity of the liquid particles in the flow passage of the pump body is less than the circumferential velocity of the impeller.

During the longitudinal vortex process, the liquid particles enter between the impeller blades many times, and the energy is transferred to the liquid particles in the flow channel through the impeller blades. Each time a liquid particle passes through the blade, it gains energy. This is also the reason why the head of the vortex pump is higher than other vane pumps under the same impeller outer diameter. Not all liquid particles pass through the impeller. As the flow rate increases, the "circular flow" weakens. When the flow is zero, the "circular flow" is the strongest and the lift is the highest. Because the liquid in the flow channel transfers energy through the impact of the liquid. At the same time, it also causes a large impact loss, so the efficiency of the vortex pump is relatively low.