do you know about the principles of vacuum pumps?

Vacuum pumps can basically be divided into two types: gas transfer pumps and gas capture pumps.

The gas transfer pump is a vacuum pump that can continuously suck and discharge gas to achieve the purpose of pumping.

The gas capture pump is a vacuum pump that allows gas molecules to be adsorbed or condensed on the inner surface of the pump, thereby reducing the number of gas molecules in the container to achieve the purpose of pumping.

In the process of vacuum pumping, it usually goes through the following stages:

When the atmosphere is pumped to the medium vacuum range, the pressure changes with time as a natural logarithmic attenuation. The pumping process is very fast and the time is extremely short.

And when going from medium vacuum to high vacuum range, the desorption of surface adsorbed gas determines the pressure. Finally, in the high vacuum range, the gas molecules adsorbed on the surface are gradually exhausted.

Classification of vacuum

According to different pumping methods, vacuum pumps can be classified into the following categories:

Exhaust

• Positive displacement pump (positive displacement type)
• Reciprocating pump
• Rotary pump and scroll pump
• Kinetic energy type pump
• Mechanical kinetic energy transfer type (turbo-molecular pump)
• Fluid (steam)
• kinetic energy transfer type (diffusion pump)

Gas storage

• Adsorption type pump (surface adsorption type pump)
• Sorption pump getter pump Cryogenic pump (cryo pump for short)
• Ion pump (ion pump)