A special group of industrial vacuum pump machinery that often go unnoticed. These are the secondary pumps, called as such as because they serve to assist the operation of the primary industrial vacuum pump. The following are some of the secondary industrial vacuum pumps in use nowadays.
- Turbomolecular Pumps. This kind of industrial vacuum pump utilizes kinetic energy in the transfer of gas molecules. This is achieved through high speed rotation of angled blades that push the gas. The pushing force provides momentum for the gas molecules to move towards the outlet.
- Vapor Diffusion Pumps. In these kinds of industrial vacuum pumps, the transfer of kinetic energy is done through heated oil which travels at high velocity. The oil attaches to the gas and carries the gas to the outlet. Then the oil is captured to be returned to the inlet for the repetition of the whole process.
- Cryopump. An industrial vacuum pump of this design operates by utilizing low temperatures produced by cryotechnology to store gases. These pumps do not carry the gases forward, but instead traps the gas and then stores it. This type of secondary pump requires frequent maintenance, as the freezing leaves deposits in the pump and in the overall mechanism.
- Sputter Ion Pump. This group of industrial vacuum pumps use chemically activated materials to combine with gases through ionization. The process is called gettering, and is effective because a magnetic field with high ionization creates plasma that captures the gases on a cathode of either titanium or tantalum. The captured gas process is called sputtering.