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Working principle and characteristics of vortex pumps: A vortex pump is a type of impeller pump, also known as a turbulent flow pump. It consists of an impeller and a pump casing. The shape of the pump casing and impeller is the biggest difference between vortex pumps and centrifugal pumps. The casing of a vortex pump is annular, while that of a centrifugal pump is a spiral-shaped volute. The impeller of a vortex pump is a disc made of steel or copper, with numerous radial blades shaped radially cut into both sides of the disc’s edge. The impeller face is in close contact with the pump body, with an axial clearance of approximately 0.10–0.15 mm. The flow channel is composed of the annular cavity between the impeller, the pump body, and the pump cover. The section in the flow channel where the inlet and outlet are separated is called a baffle, and the radial gap between the baffle and the impeller is very small. To prevent high-pressure liquid from the discharge port from leaking into the suction port. Open-type vortex pumps have longer blades, with the inner diameter of these blades being smaller than that of the flow channel; the liquid enters the impeller from the inlet and then proceeds into the flow channel. The blades of the impeller in a closed-type vortex pump are relatively short; the inner diameter of the blades is equal to the inner diameter of the flow channel. After entering the flow channel through the suction inlet, the liquid then enters the impeller from its outer periphery. The fluid enters the flow channel and impeller through the suction inlet. As the impeller rotates, since the centrifugal force acting on the fluid within the impeller is greater than that acting on the fluid in the flow channel, a vortex motion is generated between them. The axis of rotation of this vortex runs longitudinally along the flow channel; it is referred to as a longitudinal vortex. Under the action of longitudinal vortices, during the entire process from liquid intake to discharge, it can enter and exit the impeller multiple times, similar to the flow of liquid in multi-stage centrifugal pumps. The liquid gains energy each time it passes through the impeller. When the liquid flows from the impeller to the flow channel, it mixes with the liquid moving in the channel. Due to the different velocities of the two liquid streams, momentum exchange occurs during mixing, thereby increasing the energy of the liquid in the flow channel. Vortex pumps primarily rely on this longitudinal vortex to transfer energy. Working principle and characteristics of vortex pumps: Since vortex pumps can impart energy to the liquid multiple times, the head generated by a single-stage vortex pump is higher than that of a single-stage centrifugal pump. However, unlike centrifugal pumps, in a vortex pump the liquid not only moves in a vortex motion on the axis but also in a spiral motion around the impeller. Features and applications of vortex pumps: As the flow rate of a vortex pump decreases, its head increases; therefore, it is a type of pump with high head and low flow rate. Since the shaft power is highest when the flow rate is zero, the outlet valve must be fully open during startup; therefore, it is not appropriate to use valves in the discharge pipeline to regulate the flow rate. The maximum efficiency does not exceed 45%, and it is usually between 15% and 40%. Compared with centrifugal pumps of equivalent performance, vortex pumps have advantages such as small size, light weight, simple structure, and low cost, but they suffer from high energy loss of the liquid inside the pump and low efficiency. The radial and axial clearances between the impeller of a vortex pump and the pump body must be very precise; typically, the radial clearance is 0.15–0.3 mm, while the axial clearance is 0.07–0.2 mm. Therefore, such pumps are not suitable for transporting liquids that contain solid particles or have a high viscosity. It is mainly used to replace centrifugal pumps with low specific speed and high head.