Patent US4475472A successfully refreshed from Google Patents.
US4475472A
Expired / Lapsed
US
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Method and apparatus for operating a vortex bed furnace
Assignee: Steag GmbH
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Filing: 1982-07-26
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Granted: 1984-10-09
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Expires: 2002-07-26
Abstract
Abstract Known vortex bed furnaces have a relatively high structural volume in relation to the firing performance. In addition, special devices are necessary for supplying the vortex bed with fuel and with sulphur-absorbing additives. Without subdividing the bed, a partial load can only be achieved with a vortex bed furnace which differs from the full load by only a small percentage. In order to solve these problems, it is proposed according to the invention that the fuel for the vortex bed should be blown with air via at least one dust burner, unsifted, into the combustion chamber, whereby the fine portion of the fuel conducted in is burnt in the dust flame and the coarse portion drops from the dust flame into the vortex bed. The dust burner serves on the one hand to load the vortex bed and on the other hand to increase the relative firing performance, and can be used to improve the suitability for partial load.
Inventors
- 👤 Fritz Adrian
- 👤 Boris Dankow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:23
CPC Classifications
F; F23; F23C; F23C10/00; F23C10/002; F23K; F23K1/00; F23K3/00; F23K3/02
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
119 words
A method of operating a fluidized bed furnace with pulverized fuel, in particular, pit coal having, as a result of its pulverization, a fine particle portion and a coarse particle portion, said method comprising the steps of: establishing a fluidized bed; blowing a primary air flow supplying the pulverized fuel above the fluidized bed; separating the fine particle portion of the pulverized fuel from the coarse particle portion above the fluidized bed; blowing a secondary air flow concentric to said primary air flow; burning the fine particle portion of the pulverized fuel above the fluidized bed in a flame defined by the two air flows; and allowing the coarse particle portion to fall into the fluidized bed for combustion.
Claim 2
Independent Claim
119 words
A method of operating a fluidized bed furnace with pulverized fuel, in particular, pit coal having, as a result of its pulverization, a fine particle portion and a coarse particle portion, said method comprising the steps of: establishing a fluidized bed; blowing a primary air flow supplying the pulverized fuel above the fluidized bed; separating the fine particle portion of the pulverized fuel from the coarse particle portion above the fluidized bed; blowing a secondary air flow concentric to said primary air flow; burning the fine particle portion of the pulverized fuel above the fluidized bed in a flame defined by the two air flows; and allowing the coarse particle portion to fall into the fluidized bed for combustion.
Claim 3
Dependent Claim
44 words
A method according to claim 1 wherein the step of supplying the pulverized fuel is further defined as blowing an axially rotating primary air flow supplying the pulverized fuel and providing, to said primary air flow, the concentric secondary air flow with high momentum.
Claim 4
Dependent Claim
29 words
A method according to claim 2 wherein the step of supplying the pulverized fuel is further defined as providing a secondary air flow enclosed by the primary air flow.
Claim 5
Dependent Claim
18 words
A method according to claim 2 further defined as adjusting the axial rotation of the primary air flow.
Claim 6
Dependent Claim
45 words
A method according to claim 1 wherein the coarse particle portion of the pulverized fuel includes a pollution causing component and wherein the step of establishing the fluidized bed is further defined as establishing a fluidized bed containing a reactant for the pollution causing component.
Claim 7
Dependent Claim
46 words
A method according to claim 5 wherein the step of supplying the pulverized fuel is further defined as supplying the reactant along with the pulverized fuel above the fluidized bed and allowing the reactant to fall into the bed to react with the pollution causing component.
Claim 8
Dependent Claim
49 words
A method according to claim 1 wherein the coarse particle portion of the pulverized fuel includes a pollution causing component and wherein the step of establishing the fluidized bed is further defined as establishing a cooled fluidized bed for reducing production of pollutants by combustion in the fluidized bed.
Claim 9
Dependent Claim
20 words
A method according to claim 1 including the initial step of pulverizing the fuel by subjecting the fuel to impact.
Claim 10
Dependent Claim
13 words
A method according to claim 8 wherein the fuel undergoes single impact pulverization.
Claim 11
Dependent Claim
43 words
A method according to claim 9 wherein the step of pulverizing the fuel is further defined as accelerating the fuel by an air flow to a speed corresponding to the desired degree of pulverization and applying the accelerated fuel to an impact plate.
Claim 12
Dependent Claim
28 words
A method according to claim 8 wherein the step of pulverizing the fuel is further defined as varying the impact momentum of the fuel in the pulverizing step.
Claim 13
Dependent Claim
30 words
A method according to claim 1 further including the step of igniting the fluidized bed by radiant heat produced by the burning of the pulverized fuel above the fluidized bed.
Claim 14
Dependent Claim
41 words
A method according to claim 8 further defined as collecting at least a portion of a fine dust-like portion of the fuel produced by impact pulverization and using the collected portion as igniting fuel for the burning of the pulverized fuel.
Claim 15
Dependent Claim
15 words
A method according to claim 8 further defined as drying the fuel before impact pulverization.
Claim 16
Dependent Claim
15 words
A method according to claim 8 further defined as drying the fuel during impact pulverization.
Claim 17
Dependent Claim
33 words
A method according to claim 1 further defined as burning the fine particle portion of the fuel in an under stoichiometric state and operating the fluidized bed with an excess of combustion air.
Claim 18
Dependent Claim
43 words
A method according to claim 1 wherein the fluidized bed has a gas flow therethrough and wherein the method is further defined as blowing the primary air and pulverized fuel in the same direction as the flue gas flow of the fluidized bed.
Claim 19
Dependent Claim
40 words
A method according to claim 1 wherein the fluidized bed has a gas flow therethrough and wherein the method is further defined as blowing the primary air and pulverized fuel opposite to the flue gas flow of the fluidized bed.
Claim 20
Dependent Claim
150 words
A furnace for burning pulverized fuel, in particular pit coal, having, as a result of its pulverization, a fine particle portion and a coarse particle portion, said furnace comprising: a combustion chamber; a fluidized combustion bed in said chamber; air supply means for said fluidized bed fluidizing and permitting combustion in said bed; supply means for the pulverized fuel; and an annular pulverized fuel burner in said chamber, said pulverized fuel burner having a primary air-fuel supply tube connected to said pulverized fuel supply means and a concentric secondary air tube, said fuel burner being positioned in said chamber for discharging the pulverized fuel above said fluidized bed, said fuel burner separating the fine particle portion of the fuel from the coarse portion above said fluidized bed, burning the fine particle portion above said fluidized bed, and allowing the coarse particle portion to fall into the fluidized bed for combustion.
Claim 21
Dependent Claim
150 words
A furnace for burning pulverized fuel, in particular pit coal, having, as a result of its pulverization, a fine particle portion and a coarse particle portion, said furnace comprising: a combustion chamber; a fluidized combustion bed in said chamber; air supply means for said fluidized bed fluidizing and permitting combustion in said bed; supply means for the pulverized fuel; and an annular pulverized fuel burner in said chamber, said pulverized fuel burner having a primary air-fuel supply tube connected to said pulverized fuel supply means and a concentric secondary air tube, said fuel burner being positioned in said chamber for discharging the pulverized fuel above said fluidized bed, said fuel burner separating the fine particle portion of the fuel from the coarse portion above said fluidized bed, burning the fine particle portion above said fluidized bed, and allowing the coarse particle portion to fall into the fluidized bed for combustion.
Claim 22
Dependent Claim
21 words
A furnace according to claim 19 wherein said pulverized fuel burner extends through said fluidized bed in a generally central position.
Claim 23
Dependent Claim
21 words
A furnace according to claim 19 wherein said dust pulverized burner is mounted in said combustion chamber above said fluidized bed.
Claim 24
Dependent Claim
33 words
A furnace according to claim 19 wherein said burner has a central secondary air tube and a concentric primary air-fuel supply tube having means for spirally rotating the air about the discharge axis.
Claim 25
Dependent Claim
39 words
A furnace according to claim 19 wherein the coarse particle portion of the pulverized fuel includes a pollution causing component and wherein said furnace includes means for supplying a reactant to the fluidized bed for the pollution causing component.
Claim 26
Dependent Claim
42 words
A furnace according to claim 23 wherein said reactant supply means includes said pulverized fuel burner, said reactant being discharged by said pulverized fuel burner above said fluidized bed and falling into said fluidized bed for reaction with the pollution causing component.
Claim 27
Dependent Claim
43 words
A furnace according to claim 19 wherein the coarse particle portion of the pulverized fuel includes a pollution causing component and wherein said furnace includes cooling means for said fluidized bed for reducing the production of pollutants by combustion in said fluidized bed.
Claim 28
Dependent Claim
25 words
A furnace according to claim 19 further including an after-burning chamber connected to the combustion chamber and means providing after-burning air to said after-burning chamber.
Claim 29
Dependent Claim
18 words
A furnace according to claim 19 wherein said fuel supply means includes impact pulverization means for said fuel.
Claim 30
Dependent Claim
139 words
A furnace according to claim 27 wherein said pulverized fuel burner has a primary air-fuel supply tube connected to an air supply and wherein said fuel supply means further includes pulverization means comprising: a housing having an upper end and lower end; an impact plate arranged in said housing; and impact nozzle in said housing connected to a fuel source and said air supply for pneumatically projecting fuel against said impact plate to pulverize same; said lower end of said housing being connected to said primary air supply tube of said pulverized fuel burner for supplying pulverized fuel to said burner, said upper end of said housing being connected with said primary air tube upstream of said lower end connection; and means for controlling the amount of air supplied to said impact nozzle and to said primary air tube.
Claim 31
Dependent Claim
31 words
A furnace according to claim 27 wherein said fuel supply means has filter means for separating off fine fuel dust and supplying same as ignition dust for said pulverized fuel burner.
Claim 32
Dependent Claim
27 words
A furnace according to claim 19 wherein said furnace comprises a plurality of selectively utilizable combustion elements, each comprising a fluidized bed and a pulverized fuel burner.
References Cited (Backward Citations)
US519530A
Cited
GB1434371A
Cited
US4168670A
Cited
US4306854A
Cited
US4184455A
Cited
US4241670A
Cited
US4240364A
Cited
US4259911A
Cited
US4333405A
Cited
US4332207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-09 | 1988-04-09 | 1988-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-09 | 1992-04-09 | 1992-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-09 | 1996-04-09 | 1996-10-09 | $7700.00 | Window Closed / Lapsed |