The utility model relates to a liquid ring vacuum pump, which comprises a pump shell and an impeller which are eccentrically installed in the pump shell. Impeller is made of material with elastic modulus less than 4000N / mm2. Further relates to an impeller for such a pump.
What design impeller of liquid ring vacuum pump must meet?
Liquid ring vacuum pump is widely used in our daily life, and its design is also very rigorous. Today we will understand the design requirements that the impeller of liquid ring vacuum pump must meet:
(1) The stress requirements are determined by the strength limit of the material. Therefore, it is necessary to accurately predict the steady state of impeller and the vibration stress of impeller in complex shape and high speed.
(2) The requirement of fluid power is to solve the problem of large turning and large expanding of impeller at high flow rate, and to solve other problems when passing through the small passage with high efficiency and high pressure.
(3) Although the impeller can achieve very high efficiency, but the component matching is a basic square of design. Often, because of improper matching, we have to redesign the impeller, and sometimes, in order to achieve the best matching, we prefer to sacrifice the high efficiency of the impeller.
Because the liquid ring pump uses liquid to form a concentric liquid ring with the pump body in the pump body, the energy conversion is completed to form a vacuum or pressure. Because the liquid rotates with the impeller, the volume of the chamber changes periodically for suction and exhaust. The volume of the chamber between the impeller and the liquid ring changes with the position of the impeller. In the process of expansion, a vacuum is formed in the chamber, and the gas is sucked in from the suction hole; in the process of volume reduction, the gas is compressed.
When the volume of the chamber is connected with the exhaust hole, the compressed gas is discharged. When exhausting, it is inevitable that some liquid will be discharged along with it. The heat of compression produced by the liquid ring pump when compressing the gas and the heat produced by the blade stirring the liquid ring will raise the water temperature and affect the vacuum degree and air volume of the pump.