Centrifugal self-priming pump can be divided into two types: internal mixing and external mixing. Let us talk about the working principle of the internal mixing self-priming pump.

Internal mixing refers to gas-liquid mixing near the impeller inlet. Before starting the self-priming pump, appropriate amount of liquid is poured into the pump body (submerged impeller), the return valve opens, and the press-in chamber communicates with the suction chamber. After the impeller rotates, the liquid in the suction chamber and the impeller is conveyed to the press chamber through the impeller. Negative pressure is formed at the inlet of the impeller. The pressure in the suction line is higher than the pressure in the suction chamber, so that the suction valve is opened, the gas in the suction line is sucked into the impeller, and the liquid in the pressure chamber is passed through the orifice of the reflux valve and sucked. The chamber is sucked into the inlet of the impeller for gas-liquid mixing. The impeller transports the gas-liquid mixture to the press-in chamber. Because the volume of the gas-liquid separation chamber is large enough, the flow rate is reduced, and the gas and the gas are different in specific gravity. Liquid separation, gas discharge through the pressure out of the pipeline, the liquid is sucked into the impeller through the reflux valve hole and then mixed with the gas, in order to cycle until the gas in the suction pipeline is drained, then the self-priming pump is completed Self-priming process to achieve normal work.