Patent US4083181A successfully refreshed from Google Patents.
US4083181A
Expired / Lapsed
US
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Gas turbine engine with recirculating bleed
Assignee: National Aeronautics and Space Administration
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Filing: 1976-06-14
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Granted: 1978-04-11
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Expires: 1996-06-14
Abstract
Abstract A method of reducing carbon monoxide and unburned hydrocarbon emissions in a gas turbine engine by bleeding hot air from the engine cycle and introducing it back into the engine upstream of the bleed location and upstream of the combustor inlet. As this hot inlet air is recycled, the combustor inlet temperature rises rapidly at a constant engine thrust level. In most combustors, this will reduce carbon monoxide and unburned hydrocarbon emissions significantly. The preferred locations for hot air extraction are at the compressor discharge or from within the turbine, whereas the preferred re-entry location is at the compressor inlet.
Inventors
- 👤 Arthur P. Adamson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:59
CPC Classifications
F; F02; F02C; F02C3/00; F02C3/34; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
131 words
In a gas turbine engine having a compressor for pressurizing a motive fluid stream, a combustor downstream of said compressor and a turbine drivingly connected to said compressor, the improvement comprising: means for bleeding a portion of the motive fluid from a first engine location at a relatively high temperature; means for reintroducing the portion at substantially the same high temperature back into the engine motive fluid stream at a second location upstream of the combustor wherein it is mixed with motive fluid at a relatively lower temperature with respect to the bleed portion; valve means in serial flow relationship between the bleed meeans and the reintroducing means; and control means responsive to engine power setting for positioning said valve means to limit the bleed flow to low engine power operation.
Claim 2
Dependent Claim
131 words
In a gas turbine engine having a compressor for pressurizing a motive fluid stream, a combustor downstream of said compressor and a turbine drivingly connected to said compressor, the improvement comprising: means for bleeding a portion of the motive fluid from a first engine location at a relatively high temperature; means for reintroducing the portion at substantially the same high temperature back into the engine motive fluid stream at a second location upstream of the combustor wherein it is mixed with motive fluid at a relatively lower temperature with respect to the bleed portion; valve means in serial flow relationship between the bleed meeans and the reintroducing means; and control means responsive to engine power setting for positioning said valve means to limit the bleed flow to low engine power operation.
Claim 3
Dependent Claim
144 words
In a gas turbine engine having a compressor for pressurizing a motive fluid stream, a combustor downstream of said compressor and a turbine drivingly connected to said compressor, the improvement comprising: means for bleeding a portion of the motive fluid from a first engine location at a relatively high temperature; means for reintroducing the portion at substantially the same high temperature back into the engine motive fluid stream at a second location upstream of the combustor wherein it is mixed with motive fluid at a relatively lower temperature with respect to the bleed portion; and check valve means in serial flow relationship between the bleed means and the reintroducing means; and wherein the first engine location is at a higher pressure than the second location at low engine power operation, and at a lower pressure than the second location at higher engine power operation.
Claim 4
Dependent Claim
144 words
In a gas turbine engine having a compressor for pressurizing a motive fluid stream, a combustor downstream of said compressor and a turbine drivingly connected to said compressor, the improvement comprising: means for bleeding a portion of the motive fluid from a first engine location at a relatively high temperature; means for reintroducing the portion at substantially the same high temperature back into the engine motive fluid stream at a second location upstream of the combustor wherein it is mixed with motive fluid at a relatively lower temperature with respect to the bleed portion; and check valve means in serial flow relationship between the bleed means and the reintroducing means; and wherein the first engine location is at a higher pressure than the second location at low engine power operation, and at a lower pressure than the second location at higher engine power operation.
Claim 5
Dependent Claim
24 words
The engine as recited in claim 2 wherein said compressor is a multistage compressor and said second location is in the early compressor stages.
References Cited (Backward Citations)
SU158752A1
Cited
CA527041A
Cited
US2404275A
Cited
US2599470A
Cited
US2863282A
Cited
US2906092A
Cited
US3123283A
Cited
US3908362A
Cited
US3754393A
Cited
US3792581A
Cited
US3785145A
Cited
US3830058A
Cited
US3927958A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-10 | 1981-10-10 | 1982-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-10 | 1985-10-10 | 1986-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-10 | 1989-10-10 | 1990-04-11 | $7700.00 | Window Closed / Lapsed |