A vacuum pump is a piece of equipment that draws gas molecules out of a sealed chamber to create a partial vacuum or a low-pressure area. A vacuum is a situation in which the chamber pressure is lower than that of the surrounding atmosphere or systems. It’s important to note that this is not the same as absolute vacuum, which has a pressure of 0 Pa and is completely empty of gas molecules. There are various levels of vacuum that can be achieved. It can range from a low vacuum of 1 to 0.03 bars to an exceedingly high vacuum of a billionth of a Pascal.

Vacuum grippers, vacuum cleaners, incandescent bulbs, painting, sandblasting, vacuum furnaces, and negative pressure ventilation are all examples of low and medium vacuum. For laboratory applications such as particle reactors and accelerators, higher vacuum systems are used.

There are two primary types of partial vacuum generators. Gas transfer or gas feeding is one method, and entrapment is another. Vacuum pumps with gas transfer types remove gases mechanically using positive displacement or momentum transfer. To draw and eject flow, positive displacement vacuum pumps use chambers that alternately expand and contract with check or non-return valves. By accelerating gases, momentum transfer pumps create a low-pressure zone in their wake. Entrapment vacuum pumps, on the other hand, use a variety of mechanisms to capture gas molecules, including condensation, sublimation, adsorption, ionisation, and so on.