Under what circumstances are turbomolecular vacuum pumps used?

Turbomolecular vacuum pumps can reach pressure levels of 10-12 mbar. Flow rates range from 50 L to 5000 L/s. They work on the same principle as compressors. The blades at each level of the pump are rotated by a high-speed rotating motor, which exhausts air from the volume to be emptied. Such pumps are usually mounted on magnetic bearings to support high rotational speeds. They require a main pump with a vacuum limit of 10-2 mbar.

The advantage of turbomolecular vacuum pumps is that they do not require oil. Therefore, it is a clean pump. This pump is particularly suitable for ultra-high vacuum applications, such as analytical instrumentation or laboratory analysis.

Due to their complex technology, turbomolecular pumps are expensive to purchase and require more maintenance than traditional vacuum pumps. The pumping speed also depends heavily on the type of gas being pumped. For lighter gases, the speed drops dramatically.