US3580226A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Steam generator using gas recirculation
Assignee: Combustion Engineering Inc
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Filing: 1969-12-04
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Granted: 1971-05-25
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Expires: 1989-12-04
Abstract
Abstract A steam-generating unit using gas recirculation for steam temperature control, where the recirculated gases are introduced into the furnace through the ash hopper. A liquid seal inside the ash hopper is used to control flow of recirculated gases.
Inventors
- 👤 Samuel S Blackburn Jr
- 👤 Earl K Richard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:50
CPC Classifications
F; F22; F22G; F22G5/00; F22G5/06; F16; F16B; F16B39/00; F16B39/22; F16B39/28; F16B39/30; F22G5/04
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
164 words
In a steam-generating unit having a furnace and heat exchange means for generating steam therein, an ash hopper located beneath the furnace, opening means connecting the ash hopper to the furnace, first liquid seal means completely surrounding the ash hopper for preventing hot combustion gases from escaping therefrom, duct means, said duct means having an inlet end connected to the steam-generating unit downstream of the heat exchange means, and an outlet end positioned inside the first liquid seal means, means located in the duct means which when actuated will cause combustion gases to flow from the inlet end to the outlet end, and second liquid seal means surrounding the outlet end of the duct means, means for filling and draining the second liquid seal means, so that when the second liquid seal means is drained recirculated combustion gases can be introduced into the furnace through the ash hopper, and when the second liquid seal means is filled, no recirculation of combustion gases takes place.
Claim 2
Dependent Claim
164 words
In a steam-generating unit having a furnace and heat exchange means for generating steam therein, an ash hopper located beneath the furnace, opening means connecting the ash hopper to the furnace, first liquid seal means completely surrounding the ash hopper for preventing hot combustion gases from escaping therefrom, duct means, said duct means having an inlet end connected to the steam-generating unit downstream of the heat exchange means, and an outlet end positioned inside the first liquid seal means, means located in the duct means which when actuated will cause combustion gases to flow from the inlet end to the outlet end, and second liquid seal means surrounding the outlet end of the duct means, means for filling and draining the second liquid seal means, so that when the second liquid seal means is drained recirculated combustion gases can be introduced into the furnace through the ash hopper, and when the second liquid seal means is filled, no recirculation of combustion gases takes place.
Claim 3
Dependent Claim
175 words
In a steam-generating unit having a furnace and heat exchange means for generating steam therein, an ash hopper located beneath the furnace, opening means connecting the ash hopper to the furnace, water filled trough means surrounding the ash hopper, wall means extending down from the furnace into the trough means, which terminates below the water level so as to form a liquid seaL for preventing hot combustion gases from escaping therefrom, duct means, said duct means having an inlet end connected to the steam-generating unit downstream of the heat exchange means, and an outlet end positioned inside the liquid seal, the outlet end being attached to the ash hopper at a location below the wall means terminating in the trough means, a fan located in the duct means which when actuated will cause combustion gases to flow from the inlet end to the outlet end, and valve means for the duct means located downstream of the fan which can be closed to protect the fan from hot furnace combustion gases when it is not operating.
Claim 4
Dependent Claim
175 words
In a steam-generating unit having a furnace and heat exchange means for generating steam therein, an ash hopper located beneath the furnace, opening means connecting the ash hopper to the furnace, water filled trough means surrounding the ash hopper, wall means extending down from the furnace into the trough means, which terminates below the water level so as to form a liquid seaL for preventing hot combustion gases from escaping therefrom, duct means, said duct means having an inlet end connected to the steam-generating unit downstream of the heat exchange means, and an outlet end positioned inside the liquid seal, the outlet end being attached to the ash hopper at a location below the wall means terminating in the trough means, a fan located in the duct means which when actuated will cause combustion gases to flow from the inlet end to the outlet end, and valve means for the duct means located downstream of the fan which can be closed to protect the fan from hot furnace combustion gases when it is not operating.
Claim 5
Dependent Claim
16 words
The steam-generating unit set forth in claim 2, wherein the valve means is a liquid valve.
Claim 6
Dependent Claim
16 words
The steam-generating unit of claim 3, wherein the liquid valve is located within the ash hopper.
References Cited (Backward Citations)
US3155074A
Cited
US3155078A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |