US4288215A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for preheating a rotatable fluidizable bed
Assignee: Caterpillar Inc
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Filing: 1980-05-27
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Granted: 1981-09-08
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Expires: 2000-05-27
Abstract
Abstract A method for preheating a rotatable fluidizable bed (106) comprises rotating the bed chamber (112) slowly to cause the particles (114) to slowly tumble and mix. During tumbling, one or more burners (150, 160) extending into the chamber (112), heat the particles (114) until the desired operating or ignition temperature is reached. Temperature sensors (170) in thermal communication with the bed particles (114) sense the temperature and provide either an indication thereof or an initiating signal which, in the case of a rotating fluidized bed combustor (10), terminates preheating, accelerates the bed chamber (112) rotation to normal combustor (10) operating speed and/or introduces fluidizing air and/or fuel flow through the bed chamber (112).
Inventors
- 👤 George B. Grim
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:41
CPC Classifications
F; F27; F27B; F27B15/00; F27B15/02; B; B01; B01J; B01J8/00; B01J8/18; B01J8/24; B01J8/38; B01J8/382; F23; F23C; F23C10/00; F23C10/007; F23R; F23R5/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
179 words
A method for preheating a rotating fluidized bed combustor to the ignition temperature of the exothermic combustion reaction desired to occur therein, said combustor including an elongated fluidization chamber having a longitudinally extending axis and a perforated peripheral wall, a bed of pulverulent solid particles in said chamber, heating means in thermal communication with said bed, means for rotating said chamber about said axis to cause the particles to centrifugally gravitate toward said perforated peripheral wall and means for selectively initiating a flow of combustible fuel in a gaseous agent stream into said chamber through said peripheral perforated wall, said gaseous agent stream fluidizing said bed particles and said fuel reacting with said gaseous agent in said chamber, said method comprising the steps of: (a) slowly rotating said chamber at a speed sufficient to cause tumbling and mixing of said bed particles but insufficient to cause centrifugal gravitation toward said peripheral wall prior to initiating the flow of said gaseous agent stream; and (b) applying thermal energy to said tumbling particles to heat said particles to said ignition temperature.
Claim 2
Independent Claim
179 words
A method for preheating a rotating fluidized bed combustor to the ignition temperature of the exothermic combustion reaction desired to occur therein, said combustor including an elongated fluidization chamber having a longitudinally extending axis and a perforated peripheral wall, a bed of pulverulent solid particles in said chamber, heating means in thermal communication with said bed, means for rotating said chamber about said axis to cause the particles to centrifugally gravitate toward said perforated peripheral wall and means for selectively initiating a flow of combustible fuel in a gaseous agent stream into said chamber through said peripheral perforated wall, said gaseous agent stream fluidizing said bed particles and said fuel reacting with said gaseous agent in said chamber, said method comprising the steps of: (a) slowly rotating said chamber at a speed sufficient to cause tumbling and mixing of said bed particles but insufficient to cause centrifugal gravitation toward said peripheral wall prior to initiating the flow of said gaseous agent stream; and (b) applying thermal energy to said tumbling particles to heat said particles to said ignition temperature.
Claim 3
Dependent Claim
32 words
A method, as claimed in claim 1, including the steps of sensing the temperature of said particles in said bed and adjusting said combustor operating conditions when said ignition temperature is reached.
Claim 4
Dependent Claim
41 words
A method, as claimed in claim 2, wherein said adjusting step includes initiating the flow of said gaseous agent stream and increasing chamber rotational speed to a speed sufficient to cause centrifugal gravitation of said bed particles toward said peripheral wall.
Claim 5
Independent Claim
23 words
A method, as claimed in claims 1, 2 or 3, wherein said combustible fuel is particulate coal and said gaseous agent is air.
Claim 6
Independent Claim
31 words
A method, as claimed in claims 1, 2 or 3, including the step of withdrawing said heating means from thermal communication with said bed when said exothermic reaction becomes self sustaining.
References Cited (Backward Citations)
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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) | 1984-09-07 | 1985-03-09 | 1985-09-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-07 | 1989-03-09 | 1989-09-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-07 | 1993-03-09 | 1993-09-08 | $7700.00 | Window Closed / Lapsed |