Patent US3893514A successfully refreshed from Google Patents.
US3893514A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Suppression of fires in confined spaces by pressurization
Assignee: United States Department of the Navy
•
Filing: 1973-11-23
•
Granted: 1975-07-08
•
Expires: 1993-11-23
Abstract
Abstract A process for suppressing fires in confined spaces without damage to contained equipment or loss of habitability for personnel which comprises adding nitrogen to the area to increase the total gaseous pressure within the confined area while retaining the partial pressure of oxygen in the area at a level that will support life while the percent by volume of oxygen is not sufficient to support combustion.
Inventors
- 👤 Homer W Carhart
- 👤 G H Fielding
- 👤 R G Gann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:24
CPC Classifications
A; A62; A62C; A62C99/00; A62C99/0009; A62C99/0018
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
134 words
A method of extinguishing a fire in a habitable space while maintaining an environment suitable for human sustenance and activity therein, which comprises: sealing off the space to prevent gas escapement; diffusing nitrogen gas at a pressure greater than ambient into said space initially at ambient pressure and uniformly mixing said nitrogen with the gases within said habitable space and adding said diffused nitrogen gas into said confined space until the oxygen % by volume is from 10-15% with a partial pressure of oxygen of from 0.2-0.3 atmospheres with an increase in total gas pressure to 1.5 to 2.0 atmospheres; whereby the reduced oxygen % by volume is sufficient to extinguish the fire and the partial pressure of oxygen is sufficient to sustain human life and permit work activity within the increased pressure environment.
Claim 2
Independent Claim
134 words
A method of extinguishing a fire in a habitable space while maintaining an environment suitable for human sustenance and activity therein, which comprises: sealing off the space to prevent gas escapement; diffusing nitrogen gas at a pressure greater than ambient into said space initially at ambient pressure and uniformly mixing said nitrogen with the gases within said habitable space and adding said diffused nitrogen gas into said confined space until the oxygen % by volume is from 10-15% with a partial pressure of oxygen of from 0.2-0.3 atmospheres with an increase in total gas pressure to 1.5 to 2.0 atmospheres; whereby the reduced oxygen % by volume is sufficient to extinguish the fire and the partial pressure of oxygen is sufficient to sustain human life and permit work activity within the increased pressure environment.
References Cited (Backward Citations)
US2498512A
Cited
US2572006A
Cited
US3407880A
Cited
US3438445A
Cited
US3486562A
Cited
US3783946A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |