Cryopump with selective condensation and defrost
US5819545A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 25, 1997 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Nov 25, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S62/921
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
The cryopanel of a cryopump can be preferentially defrosted to remove an acid-forming or toxic gas while leaving a second gas substantially condensed upon the cryopanel thereby limiting interaction between the vapor phases of the two gases. The cryopanel is warmed to a temperature within a selective defrost range at which the first gas selectively sublimates from the cryopanel. The temperature of the cryopanel is then maintained at a temperature within this range until the cryopanel is substantially cleared of the first gas leaving the second gas substantially undisturbed as a condensate upon the cryopanel. In a preferred embodiment, the cryopanel is maintained at about 50 to 85K during standard operation before being defrosted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.