Introduction to the principle of three commonly used vacuum pumps

Liquid ring vacuum pump working principle Water ring vacuum pump (referred to as water ring pump) is a rough vacuum pump, which obtains the ultimate vacuum of 2000~4000pa, and the series atmospheric injector can be 270~670pa. The water ring pump can also be used as a compressor, called a water ring compressor. It is a low pressure compressor with a pressure range of 1~2╳105pa. The water ring pump was originally used as a self-priming pump and was gradually used in many industrial sectors such as petroleum, chemical, machinery, mining, light industry, medicine and food. In many processes of industrial production, such as vacuum filtration, vacuum water diversion, vacuum feeding, vacuum evaporation, vacuum concentration vacuum re-shock and vacuum degassing, water ring pumps are widely used. Due to the rapid development of vacuum application technology, water ring pumps have been paid attention to in the acquisition of rough vacuum. Since the gas compression in the water ring pump is isothermal, the flammable and explosive gas can be removed, and the dusty and water-containing gas can be removed, so the application of the water ring pump is increased.
  An appropriate amount of water is contained in the pump body as a working fluid. When the impeller rotates clockwise, 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 portion of the water ring is just cut with the impeller hub, and the inner surface of the upper portion of the water ring is just in contact with the tip end of the blade (actually the blade has a certain depth of insertion in the water ring). At this time, a crescent-shaped space is formed between the impeller hub and the water ring, and this space is divided by the impeller into a plurality of small cavities equal to the number of blades. If the lower part of the impeller is used as the starting point, then the volume of the small cavity becomes smaller from 180° before the rotation of the impeller, and it communicates with the suction port on the end face. At this time, the gas is sucked in, and when the inhalation is finished, the small cavity is The suction port is isolated; when the impeller continues to rotate, the small cavity becomes larger and smaller, so that the gas is compressed; when the small cavity communicates with the exhaust port, the gas is discharged outside the pump.

   In summary, the water ring pump relies on the change of the pump volume to achieve the suction, compression and exhaust, so it belongs to the variable displacement vacuum pump.