Liquid ring vacuum pump (hereinafter referred to as water ring pump) is a kind of roughing vacuum pump, the ultimate pressure it can obtain for single stage liquid ring pump is 2.66 ~ 9.31 kPa;For double stage liquid ring vacuum pump is 0.133 ~ 0.665 kPa.Water ring vacuum pump also can be used as a compressor, it belongs to low pressure compressor, its scope of pressure (1 ~ 2) X105Pa gauge pressure (under certain conditions).
Water ring vacuum pump used in petroleum, chemical industry, machinery, paper making, power, metallurgy, mining, light industry, medicine and food industries and municipal and agricultural departments of many processes, such as vacuum filter, vacuum feeding, vacuum degassing, vacuum evaporation, vacuum concentration and vacuum resurgence and so on, has been widely used, because the water ring pump compressed gas is isothermal process, so the pumping flammable, explosive gas, it also can smoke dust, water gas, therefore, the application of water ring pump mounting.
Water ring pump is made up of the impeller, pump body, vacuum exhaust plate, water in the form of water ring pump body wall, intake and exhaust mouth, auxiliary exhaust valve, etc.
Vacuum impeller is installed in the pump body, when rotating impeller, pump body into the water ring pump impeller water to be thrown around, due to the effect of centrifugal force, the water formed a similar to the pump cavity shape such as the thickness of the closed water ring.The area on the surface of the water ring pump is right wheel tangent with the impeller, the inside surface of the lower water ring coincided with the top blade contact (in fact, the leaves in the water ring there a certain insertion depth).At this point, the impeller wheel, water ring formed between a crescent-shaped space, this space is divided into impeller and blade is equal to the number of a number of small cavity.If the upper part of the impeller 0 ° as starting point, and then in front of the rotating impeller, 180 °, the small cavity volume gradually changed from small to big, the pressure reduced constantly, and the mines with suction mouth of the suction or discharge tray, when the pressure inside the small cavity space is less than the pressure of the pump container, according to the principle of balance of gas pressure, the gas is pumped continues to be draw in small cavity, is in the process of suction.When inspiratory finished with inspiratory mouth cut off, the volume of the small cavity is gradually decreases, and the pressure increases continually, at this time is in the compression process, when it comes to an exhaust pressure of compressed gas in advance, forward from the auxiliary exhaust valve exhaust, and vent interlinked small cavity volume further decrease the pressure rise further, when the pressure is greater than the exhaust pressure of the gas, the compressed air to escape from the vent is in the process of the continuous operation of the pump, rotary vane vacuum pump continuously carrying on the suction, compression, exhaust process, so as to achieve the purpose of continuous extraction.
In the water ring vacuum pump, auxiliary exhaust valve is a kind of special structure, generally USES the rubber ball valve, its role is to remove the pump in the operation process of the lack of compression and compression phenomenon.The two phenomena can cause excessive power consumption.Because there is no direct exhaust valve, water ring pump and exhaust pressure always is fixed, the compression ratio of water ring pump’t decided to port of termination of the starting position of the location and vent, however, the two position is fixed, so don’t meet the needs of the suction pressure changes.In order to solve this problem, generally set the rubber ball valve at the bottom of the exhaust outlet, so that when it comes to an exhaust pressure pump cavity early, ball valve automatically opens, the gas discharge, eliminates the phenomenon of compression.Generally when designing water ring pump on the basis of the minimum suction pressure to determine the compression ratio, in order to determine the starting position of exhaust outlet, thus solve the lack of compression phenomenon.