The vortex pump is a type of pump that has emerged since 1920. Its main working mechanism includes an impeller (a disc with radial blades on the outer rim), a pump body and an annular flow passage composed of a pump cover, a pump body and an impeller . Liquid from the suction pipe into the runner, and through the rotation of the impeller to obtain energy, is delivered to the discharge pipe to complete the pump work process. The working principle of the vortex pump, the structure and the shape of the characteristic curve are different from the centrifugal pump and other types of pumps. Is a small flow, high-lift pump, the ratio of n8 generally less than 40. 　　 According to different forms of impeller vortex pump can be divided into two types of closed and open, closed impeller blade groove with an intermediate partition; open impeller without intermediate partition. 　　 Closed vortex pump 　　 1, closed vortex pump structure: mainly by the impeller, pump body, separated tongue composition. Both ends of the runner (or one end) communicate with the inlet, which is called open runner. Impeller open balance hole for balancing axial force. The liquid enters through the inlet and makes vertical eddy movement driven by the impeller to gain energy, which is discharged from the outlet. The liquid near the outlet leaves returns to the pump inlet with the impeller. 　　 1, impeller; 2, pump housing; 3, tongue; 4, runner; 5, balance hole 　　 2, closed vortex pump features 　　 (1) closed self-priming pump does not self-priming, not suitable for gas-liquid mixed transport. 　　 The inlet gas is mixed with the liquid into the vane groove. Due to the different density of liquid and gas, the liquid with high density is thrown to the outside of the vane groove and the flow channel under the action of centrifugal force. The gas stays in the root of the vane groove and flows out from the outlet on the outlet side. The gas in the root of the blade groove returns to the inlet with the impeller, and the exhaust can not be realized. Closed vortex pump to have self-absorption capacity, the need to add an auxiliary device on the outlet side, so that the flow of liquid to the roots of the groove leaves the gas discharge, and gas-liquid separation and liquid backflow structure. 　　 (2) closed vortex pump cavitation performance is poor. 　　 The inlet flow from the outer edge of the impeller to the root of the blade groove, uneven distribution of velocity, the impact of larger, so closed vortex cavitation performance as open vortex pump. 　　 (3) closed vortex pumps are generally single or two. 　　 (4) Closed vortex pump efficiency is generally 35% to 45%, higher than the open vortex pump. 　　 Open vortex pump 　　 1, Open vortex pump structure: Closed vortex pump with open flow channel is different, open type vortex pump usually adopts closed flow channel, inlet and outlet open at the root of the blade, and the flow channel are unrelated with each other. In addition to the closed runner structure, the open vortex pump also has a centripetal open-flow structure. Both structures have self-priming capability. 　　 The flow rate of the vortex pump can be as small as 0.05 l / s or less and as large as 12.5 l / s. Single-stage lift up to 300m, when the specific rotation of more than 40, because of its efficiency lower than the centrifugal pump, therefore, less used. 　　 Vortex pumps have the following advantages over other types of pumps: 　　 1. Vortex pump is a very simple structure of the high-lift pump, and the same size, number of revolutions compared to the same pump, the pump head 2-4 times higher. Compared with the same head volume pump, its size is small, the structure is simple. 　　 Small size and light weight of the vortex pump have great advantages in marine installations. 　　 2. Self-priming or self-priming with simple device. 　　 3. With a steep drop of the lift characteristic, it is insensitive to pressure fluctuations in the system. 　　 4. Some vortex pumps to achieve liquid-vapor mixed. This is of great importance for pumping volatile liquids containing gases and high-temperature liquids with high vapor pressure. 　　 5. Vortex pump structure is simple, casting and machining processes are easy to achieve, some of the vortex pump parts can also use non-metallic materials, such as plastic, nylon molded impeller. 　　 Disadvantages of the vortex pump: 　　 1. Lower efficiency, up to 50%, most of the efficiency of the vortex pump 20% -40%, thus preventing it from the direction of high-power development. 　　 2. Vortex pump cavitation performance is poor. 　　 3. The vortex pump can not be used to pump more viscous media. As the viscosity of the liquid increases, the head and efficiency of the pump will decrease drastically and the viscosity of the medium will be limited to 114 centistokes (15 ° E). 　　 4. Vortex pump impeller and pump radial clearance and axial clearance between the more stringent requirements (the general radial clearance of 0.15 ~ 0.3mm, unilateral axial clearance of 0.07 ~ 0.15mm) to the processing and assembly process with To some difficulty. 　　 5. Pumped medium is limited to pure liquid. When liquids contain solid particles, they can degrade pump performance or cause the vortex pump to become inoperable due to increased axial and radial clearance due to wear. 　　 As the vortex pump has the above characteristics, in recent years, all countries have made great progress in the theoretical research, calculation methods and product varieties of the vortex pump. Vortex pumps are also gaining popularity in many sectors of the national economy, such as those used in chemical complexes to pump small volumes and high-lift acids, alkalis and other corrosive and volatile chemical liquids. Refueling Cars, tankers and fixed distribution devices are used to pump volatile liquids such as gasoline, kerosene and alcohol. They are used as mobile and stationary fire pumps, ships' water pumps, and for boosting and pumping makeup water.