Patent FR803638A successfully refreshed from Google Patents.
US4755201A
Expired / Lapsed
US
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Process for removing lighter volatile impurities from gases
Assignee: Messer Griesheim GmbH
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Filing: 1986-04-17
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Granted: 1988-07-05
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Expires: 2006-04-17
Abstract
Abstract Lighter volative impurities are removed from gases by drawing the gas to be purified into a vacuum system. The gas to be purified deposits onto the cold surface of a condenser which is at cryogenic temperatures, while the lighter volatile impurities are continuously pulled out of the vacuum system in gaseous form.
Inventors
- 👤 Manfred Eschwey
- 👤 Werner Schleser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 13:53
CPC Classifications
B; B01; B01D; B01D8/00
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
117 words
In a process for removing lighter volatile impurities from gases in order to obtain the gases in highly purified form, the improvement being in continuously feeding the gas to be purified into a condenser by means of a gas transfer pump communicating with the condenser, cooling a surface of the condenser at cryogenic temperatures between -100° C. and -200° C. on a cold surface of the condenser to which the gas is exposed, condensing the gas by means of the gas contacting the cold surface to form a deposit from the gas to be purified with the lighter volatile impurities remaining in gaseous form, and continuously withdrawing the lighter volatile impurities in gaseous form from the condenser.
Claim 2
Dependent Claim
117 words
In a process for removing lighter volatile impurities from gases in order to obtain the gases in highly purified form, the improvement being in continuously feeding the gas to be purified into a condenser by means of a gas transfer pump communicating with the condenser, cooling a surface of the condenser at cryogenic temperatures between -100° C. and -200° C. on a cold surface of the condenser to which the gas is exposed, condensing the gas by means of the gas contacting the cold surface to form a deposit from the gas to be purified with the lighter volatile impurities remaining in gaseous form, and continuously withdrawing the lighter volatile impurities in gaseous form from the condenser.
Claim 3
Dependent Claim
22 words
Process according to claim 1, characterized therein that at the end of the process the purified gas is removed from the condenser.
Claim 4
Dependent Claim
22 words
Process according to claim 1, characterized therein that lighter volatile components are drawn off by means of a gas transfer vacuum pump.
Claim 5
Dependent Claim
32 words
Process according to claim 3, characterized therein that the cold surface of the condenser is held at temperatures between -100° C. and -200° C. by liquid nitrogen using a regulated cooling apparatus.
Claim 6
Dependent Claim
58 words
Process according to claim 4, characterized therein that the gas to be purified is a gas from the group of silane, disilane, dichlorosilane, germane, borane, arsine, hydrogen chloride, ammonia and tetrafluoromethane while the impurities to be removed consist of one or more gases from the group of hydrogen, nitrogen, oxygen, inert gases, hydrocarbons, carbon dioxide and carbon monoxide.
Claim 7
Dependent Claim
32 words
Process according to claim 1, characterized therein that the cold surface of the condenser is held at temperatures between -100° C. and -200° C. by liquid nitrogen using a regulated cooling apparatus.
Claim 8
Dependent Claim
58 words
Process according to claim 1, characterized therein that the gas to be purified is a gas from the group of silane, disilane, dichlorosilane, germane, borane, arsine, hydrogen chloride, ammonia and tetrafluoromethane while the impurities to be removed consist of one or more gases from the group of hydrogen, nitrogen, oxygen, inert gases, hydrocarbons, carbon dioxide and carbon monoxide.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-07-05 | 1992-01-04 | 1992-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-05 | 1996-01-04 | 1996-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-05 | 2000-01-04 | 2000-07-05 | $7700.00 | Window Closed / Lapsed |