The order of a Chinese company includes the manufacturing of a batch of cryogenic vacuum pumps of the series Coolvac for the evacuation of space simulation chambers. These pumps with a flange diameter of 1.3 m anr pumping at rate of 60,000 litres per second for nitrogen. Cryo pumps are used wherever very large vacuum chambers need to be evacuated very rapidly to extremely low pressures, offering high pumping rates and an attainable vacuum of down to 10-12 mbar.
The Coolvac series of cryo pumps are gas-binding vacuum pumps for the high vacuum pressure range of 10-3 mbar to 10-11 mbar. These pumps work on the principle that gaseous substances become bound to cold surfaces inside the pump by cryogenic condensation, cryo sorption or cryo trapping. To produce a high or ultra-high vacuum, all cold surfaces must be cooled to a sufficiently low temperature. Depending on the type of cooling system used, a distinction is made between refrigerator cryo pumps, bath cryo pumps and evaporator cryo pumps. Oerlikon Leybold Vacuum manufactures exclusively refrigerator-cooled cryo pumps.