US3586098A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Concentric tube heat exchanges
Assignee: AMERICAN SCHACK CO Inc
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Filing: 1970-02-05
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Granted: 1971-06-22
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Expires: 1990-02-05
Abstract
Abstract A multistage recuperator-type heat exchanger has a plurality of recuperator tubes suspended in an elongate recuperator chamber through which a heating gas flows. Each of the recuperator tubes has an inner tube concentrically positioned in an outer tube. The outer tube has a closed bottom end portion and an open upper end connected to a heated gas outlet compartment of a header. The inner tube has an open bottom end portion that terminates adjacent the closed bottom end of the outer tube and an open upper end connected to an inlet compartment of the header through which gas to be heated is introduced into the inner tube. The gas to be heated flows downwardly through the inner tube to the open bottom end upwardly in the annular passageway between the tubes and absorbs heat from the inner surface of the outer tube. Some of the recuperator tubes adjacent the heating gas inlet end of the recuperator, where the heating gas is at its highest temperature, have groups of spaced apertures therethrough around the circumference of the tube. The groups of apertures are located at different elevations along the length of the tube. A portion of the gas to be heated flows outwardly through the apertures and sweeps the inner surface of the outer tube at the different elevations and absorbs the heat from the outer tube and reduces the temperature thereof.
Inventors
- 👤 Gert Wellensiek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:08
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/10; F28D7/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
331 words
A recuperator heat exchanger comprising, an elongate recuperator chamber having an inlet portion and an outlet portion, means for introducing gaseous combustion products from an industrial furnace into the inlet end portion of said recuperator chamber and circulating gaseous combustion products through said recuperator chamber, said gaseous combustion products being at the highest elevated temperature within said recuperator chamber adjacent said recuperator chamber inlet portion, a plurality of headers spaced longitudinally along said recuperator chamber, said headers each having a plurality of recuperator tubes extending therefrom into said recuperator chamber, each recuperator tube including an inner tube positioned concentrically in an outer tube, said outer tube having one end communicating with said header and a closed end within said recuperator chamber, said inner tube concentrically positioned within said outer tube and having an end portion communicating with said header and the other end portion in Close proximity to the closed end portion of said outer tube, a cold gas supply duct communicating through said header with said inner tube, a hot gas discharge duct communicating through said headers with said outer tube, means for establishing flow of cold gas from said headers through said inner tube to said end portion adjacent said outer tube closed end portion and then upwardly through said annular passage between the inner surface of said outer tube and the outer surface of said inner tube to said header and said hot gas discharge duct, said gaseous combustion products at side elevated temperature arranged to heat the outer tubes of said recuperator tubes so that said outer tubes transfer heat to said gas flowing upwardly between said inner tube and said outer tube, and means for introducing a portion of said cold gas in said recuperator tubes positioned in said recuperator chamber adjacent said recuperator chamber inlet at locations spaced upwardly from the closed end of said outer tube to cool portions of the outer tubes subjected to the highest elevated temperature of said gaseous combustion product.
Claim 2
Dependent Claim
331 words
A recuperator heat exchanger comprising, an elongate recuperator chamber having an inlet portion and an outlet portion, means for introducing gaseous combustion products from an industrial furnace into the inlet end portion of said recuperator chamber and circulating gaseous combustion products through said recuperator chamber, said gaseous combustion products being at the highest elevated temperature within said recuperator chamber adjacent said recuperator chamber inlet portion, a plurality of headers spaced longitudinally along said recuperator chamber, said headers each having a plurality of recuperator tubes extending therefrom into said recuperator chamber, each recuperator tube including an inner tube positioned concentrically in an outer tube, said outer tube having one end communicating with said header and a closed end within said recuperator chamber, said inner tube concentrically positioned within said outer tube and having an end portion communicating with said header and the other end portion in Close proximity to the closed end portion of said outer tube, a cold gas supply duct communicating through said header with said inner tube, a hot gas discharge duct communicating through said headers with said outer tube, means for establishing flow of cold gas from said headers through said inner tube to said end portion adjacent said outer tube closed end portion and then upwardly through said annular passage between the inner surface of said outer tube and the outer surface of said inner tube to said header and said hot gas discharge duct, said gaseous combustion products at side elevated temperature arranged to heat the outer tubes of said recuperator tubes so that said outer tubes transfer heat to said gas flowing upwardly between said inner tube and said outer tube, and means for introducing a portion of said cold gas in said recuperator tubes positioned in said recuperator chamber adjacent said recuperator chamber inlet at locations spaced upwardly from the closed end of said outer tube to cool portions of the outer tubes subjected to the highest elevated temperature of said gaseous combustion product.
Claim 3
Dependent Claim
70 words
A recuperator heat exchanger as set forth in claim 1 in which, certain of said inner tubes of said recuperator tubes positioned adjacent the inlet end portion of said recuperator chambers having openings therein between said inner tube end portions, said openings forming outlet passages into said annular passageway between said inner tube and said outer tube for a portion of said cold gas flowing downwardly in said inner tube.
Claim 4
Dependent Claim
95 words
A recuperator heat exchanger as set forth in claim 2 in which, said openings permit a portion of said cold gas to sweep across the inner surface of said outer tube and remove heat from said outer tube at a location above said closed end portion. 4. A recuperator heat exchanger as set forth in claim 2 in which, said openings include groups of spaced apertures around the circumference of said inner tubes so that said cold gas flowing therethrough sweeps across the inner circumference of said outer tube between said inner tube end portions.
Claim 5
Dependent Claim
47 words
A recuperator heat exchanger as set forth in claim 5 in which, said groups of spaced apertures are located at different elevations along the length of said inner tube so that said cold gas flows outwardly therefrom at different locations along the length of said outer tube.
Claim 6
Dependent Claim
78 words
A recuperator heat exchanger as set forth in claim 1 which includes, means to mix a portion of the incoming cold gas with the heated gas flowing upwardly through said annular passage between said tubes to reduce the temperature of said gas flowing upwardly through said annular passage and increase the rate of heat transfer between said outer tube and said gas flowing upwardly between said tubes at a location above the closed end of said outer tube.
Claim 7
Dependent Claim
173 words
A concentric tube heat exchanger comprising, an inner tube having an open upper end portion and an open lower end portion, an outer tube having an open upper end portion and a closed lower end portion, said inner tube positioned concentrically within said outer tube with said lower open end portion adjacent said outer tube closed end portion and forming an annular gas flow passageway between the outer surface of said inner tube and the inner surface of said outer tube, means to circulate a cold gas to be heated downwardly through said inner tube against the inner surface of said outer tube closed end portion and upwardly through said annular gas flow passageway and discharged through said outer tube open upper end portion, means to heat said outer tube to transfer heat therefrom to said gas flowing upwardly in said annular passageway, and means for introducing a portion of said cold gas into said annular gas flow passageway adjacent at least said outer tube upper portion to cool said tube upper portion.
Claim 8
Dependent Claim
173 words
A concentric tube heat exchanger comprising, an inner tube having an open upper end portion and an open lower end portion, an outer tube having an open upper end portion and a closed lower end portion, said inner tube positioned concentrically within said outer tube with said lower open end portion adjacent said outer tube closed end portion and forming an annular gas flow passageway between the outer surface of said inner tube and the inner surface of said outer tube, means to circulate a cold gas to be heated downwardly through said inner tube against the inner surface of said outer tube closed end portion and upwardly through said annular gas flow passageway and discharged through said outer tube open upper end portion, means to heat said outer tube to transfer heat therefrom to said gas flowing upwardly in said annular passageway, and means for introducing a portion of said cold gas into said annular gas flow passageway adjacent at least said outer tube upper portion to cool said tube upper portion.
Claim 9
Dependent Claim
52 words
A concentric tube heat exchanger as set forth in claim 7 In which, said inner tube includes a plurality of openings therein between said inner tube end portions, said openings forming outlet passages into said annular gas flow passageway for a portion of said cold gas flowing downwardly in said inner tube.
Claim 10
Dependent Claim
84 words
A concentric tube heat exchanger as set forth in claim 7 which includes means to mix a portion of said incoming cold gas with the heated gas flowing upwardly through said annular gas flow passageway to reduce the temperature of said gas flowing upwardly through said annular gas flow passageway and increase the rate of heat transfer between said outer tube and said gas flowing upwardly in said annular gas flow passageway at a location above the closed end portion of said outer tube.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-21 | 1974-12-21 | 1975-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-21 | 1978-12-21 | 1979-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-21 | 1982-12-21 | 1983-06-22 | $7700.00 | Window Closed / Lapsed |