Water ring vacuum pump (referred to as water ring pump) is a rough vacuum pump, it can get the ultimate vacuum of 2000 ~ 4000Pa, series of atmospheric ejectors up to 270 ~ 670Pa. Water ring pump can also be used as a compressor, called the water ring compressor, is a low pressure compressor, the pressure range of 1 ~ 2 × 105Pa gauge pressure. Water ring pump was originally used as a self-priming pump, and then gradually used in petroleum, chemical, machinery, mining, light industry, medicine and food and many other industrial sectors. In many industrial processes, such as vacuum filtration, vacuum water diversion, vacuum feed, vacuum evaporation, vacuum concentration, vacuum resurgence and vacuum degassing, water ring pump is widely used. Due to the rapid development of vacuum application technology, water ring pumps have gained much attention in the area of ​​rough vacuum. As the water ring pump gas compression is isothermal, it can be extracted flammable and explosive gases, in addition to pumping dust, water-containing gas, therefore, water ring pump applications are increasing. In the pump body with the right amount of water as the working fluid. When the impeller rotates clockwise in the figure, the water is thrown around by the impeller. Due to the centrifugal force, the water forms a closed ring of approximately equal thickness depending on the shape of the pump chamber. The inner surface of the lower part of the water ring is just tangential to the hub of the impeller. The upper inner surface of the water ring is just in contact with the top of the blade (in fact, the blade has a certain insertion depth in the water ring). At this moment, a crescent-shaped space is formed between the impeller hub and the water ring, and the space is divided into a plurality of small cavities equal to the number of the blades by the impeller. If the lower part of the impeller 0 ° as a starting point, then the impeller 180 ° before the rotation of the small chamber volume from small to large, and the end of the suction port communicating, when the gas is inhaled, when the inhalation end of the small cavity When the impeller continues to rotate, the small cavity becomes smaller and the gas is compressed; when the small chamber communicates with the exhaust port, the gas is discharged outside the pump. In summary, the water ring pump is based on changes in the volume of the pump to achieve suction, compression and exhaust, so it belongs to the varactor vacuum pump.
