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US4829035A
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Reactivation of a tin oxide-containing catalyst
Assignee: National Aeronautics and Space Administration
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Filing: 1987-11-05
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Granted: 1989-05-09
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Expires: 2007-11-05
Abstract
Abstract A method for the reactivation of a tin oxide-containing catalyst of a CO 2 laser is provided. First, the catalyst is pretreated by a standard procedure. When the catalyst experiences diminished activity during usage, the heated zone surrounding the catalyst is raised to a temperature which is the operating temperature of the laser and 400° C. for approximately one hour. The catalyst is exposed to the same laser gas mixture during this period. The temperature of the heated zone is then lowered to the operating temperature of the CO 2 laser.
Inventors
- 👤 Billy T. Upchurch
- 👤 Irvin M. Miller
- 👤 Kenneth G. Brown
- 👤 Robert V. Hess
- 👤 David R. Schryer
- 👤 Barry D. Sidney
- 👤 George M. Wood
- 👤 Patricia A. Paulin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:35
CPC Classifications
B; B01; B01J; B01J38/00; B01J38/02; B01J23/00; B01J23/90; B01J23/96
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
123 words
A method for reactivating a catalyst comprised of tin oxide and a noble metal, wherein said catalyst is used to combine a laser gas mixture of CO and O 2 to form CO 2 for use in a CO 2 laser having an operating temperature between about 23° C. and 110° C., said method comprising: exposing the catalyst to a stream of the laser gas mixture which is drawn from and returned to the laser; increasing the ambient temperature surrounding the catalyst between a temperature above the operating temperature of the laser and 400° C. for a time sufficient to reactivate the catalyst; reducing said ambient temperature to the operating temperature of the laser; whereby the combination activity of the catalyst is improved.
Claim 2
Independent Claim
123 words
A method for reactivating a catalyst comprised of tin oxide and a noble metal, wherein said catalyst is used to combine a laser gas mixture of CO and O 2 to form CO 2 for use in a CO 2 laser having an operating temperature between about 23° C. and 110° C., said method comprising: exposing the catalyst to a stream of the laser gas mixture which is drawn from and returned to the laser; increasing the ambient temperature surrounding the catalyst between a temperature above the operating temperature of the laser and 400° C. for a time sufficient to reactivate the catalyst; reducing said ambient temperature to the operating temperature of the laser; whereby the combination activity of the catalyst is improved.
Claim 3
Dependent Claim
17 words
The method of claim 1 wherein the ambient temperature surrounding the catalyst is increased to 225° C.
Claim 4
Dependent Claim
26 words
The method of claim 2 wherein said temperature of 225° C. is maintained for one hour prior to reduction to the operating temperature of the laser.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the laser gas mixture contains a rare oxygen isotope in the CO 2 molecule.
Claim 6
Dependent Claim
17 words
The method of claim 4 wherein the oxide of the catalyst contains the same rare oxygen isotope.
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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) | 1992-05-08 | 1992-11-07 | 1993-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-05-08 | 1996-11-07 | 1997-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-05-08 | 2000-11-07 | 2001-05-09 | $7700.00 | Window Closed / Lapsed |