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How Does A Vacuum Pump Work?

A vacuum pump can be described as a device that serves as a tool in removing gas molecules from a sealed space, so as to create a partial vacuum. In simpler terms, vacuum pumps serve to pull gases or air out of a container leaving it free from gas molecules.

Vacuum pumps are classified as either primary pumps, secondary pumps, and booster pumps. These pumps are categorized on the basis of their operating pressure range. For each pressure range, there are several pump types. Each of these types uses its own unique technology and has its own benefits with regards to maintenance costs, flow rate, and pressure capacity.

For you to create a vacuum in a space or system, you’ll be required to move all the gas molecules from the system. Moving these molecules will only be possible if there is a variance in pressure between two areas. The area with the least number of molecules will have a lower pressure while the area with the higher number of molecules will have higher pressure.

A pump has the capacity to trigger a difference in pressure between two areas of space. The pump that forms a vacuum in this space is what is referred to as a vacuum pump.

Different Vacuum Pump Categories And How They Work

Vacuum pumps employ two types of technologies; Gas capture and Gas transfer. To get a better understanding of how these technologies work, it’s essential that you know the three different categories of vacuum pumps that exist;

1.    Transfer Pump

This pump functions by moving gas molecules through positive displacement or kinetic action. The number of gas molecules discharged from the pump are equal to those that enter into it. The gas has a slightly higher atmospheric pressure when it is being discharged.

Transfer pumps also known as kinetic pumps direct gas to the pump outlet using high-speed blades. These pumps don’t usually have sealed volumes but they have the potential to attain a high compression ratio at low pressure. When the vacuum level is attained, the tank is sealed using a high vacuum valve which prevents gas exchange between the pump and the container.

2.    Trapping Pump

This type of vacuum pump functions by automatically trapping gas volume and then pushing it through the pump. This trapped gas is compressed at high pressure into a small volume and then expelled off either to the next pump or into the atmosphere. Two transfer pumps can be used concurrently to provide greater vacuum and a higher flow rate.

3.    Capture Pump

The capture pump functions by capturing gas molecules on surfaces in the vacuum system. These pumps have lower flow rates compared to transfer pumps but have the capacity to offer ultra-high vacuum.

Capture pumps employ either cryogenic condensation, chemical reaction, or ionic reaction in their operation. They, however, have no moving parts.

Examples of primary vacuum pumps include the Oil Sealed Rotary Vane pump, the Liquid Ring pump, the Diaphragm pump, and the Scroll pump. Examples of secondary pumps include Turbomolecular pumps, Vapor Diffusion pumps, Cryopumps, and the Sputter Ion pumps. Examples of Booster pumps include the Roots pump, Claw pump, and the Screw pump.


Now you know how vacuum pumps work. Are you planning to make a vacuum pump purchase? You can get quality ones from Provac Vacuum.

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