Rapid Regeneration System for Cryogenic Pumps
Original Publication Date: 1987-Sep-01
Included in the Prior Art Database: 2005-Feb-01
This method reduces the time required to regenerate cryogenic pumps. A third stage is incorporated into the cryopump using a "Polycold" system to provide sufficient heating to desorb materials. Cryogenic pumps used for vacuum systems reduce system availability, due to the need for periodic regeneration. In pumps for thin film evaporation systems, regeneration may take 6-8 hours due to the inability to introduce sufficient heat to rapidly desorb condensed gases. Some methods use a system whereby hot N2 gas bleeds through the secondary stage of the pump to speed regeneration by about 10-15%, but requiring a large volume of N2 at high temperatures. Here, cryopump 1 has a coil/shroud 2 surrounding the first stage of the pumping head 3 and extending to the bottom of pumping unit housing 4.