Patent US4485747A successfully refreshed from Google Patents.
US4485747A
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US
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Reducing pollutant emissions by fines removal
Assignee: United States, AS REPRESENTED BY ADMINISTRATOR US ENVIRONMENTAL PROTECTION AGENCY
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Filing: 1983-07-15
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Granted: 1984-12-04
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Expires: 2003-07-15
Abstract
Abstract A method and apparatus for reducing pollutant emissions, and in particular, for reducing NO x and particulate emissions, from a spreader-stoker-fired furnace and from a fluidized bed combustor. A combustible material of various sized particles is obtained and those smaller particles which would normally combust during the suspension phase of the spreader-stoker-fired furnace or fluidized bed combustor are separated from the larger particles. The larger particles of combustible material are then introduced into the spreader-stoker-fired furnace or fluidized bed combustor and combusted to produce heat.
Inventors
- 👤 David W. Pershing
- 👤 George B. Martin
- 👤 James M. Munro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:28
CPC Classifications
B; B07; B07B; B07B9/00; B07B1/00; B07B1/10; F; F23; F23B; F23B1/00; F23B1/16; F23B1/22; F23C; F23C10/00; F23C10/002; F23K; F23K1/00
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
112 words
A method for reducing NO x and particulate pollutant emissions from a furnace having a suspension region, the method comprising the steps of: obtaining a combustible material of variously sized particles; separating smaller particles of the combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of the combustible material, thereby minimizing the formation of NO x and particulate emissions during combustion in the suspension region of the furnace; introducing the larger particles of combustible material, from which smaller particles of combustible material have been separated, into the suspension region of the furnace; and combusting the combustible material within the furnace to produce heat.
Claim 2
Independent Claim
112 words
A method for reducing NO x and particulate pollutant emissions from a furnace having a suspension region, the method comprising the steps of: obtaining a combustible material of variously sized particles; separating smaller particles of the combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of the combustible material, thereby minimizing the formation of NO x and particulate emissions during combustion in the suspension region of the furnace; introducing the larger particles of combustible material, from which smaller particles of combustible material have been separated, into the suspension region of the furnace; and combusting the combustible material within the furnace to produce heat.
Claim 3
Dependent Claim
14 words
A method as defined in claim 1 wherein the furnace is a spreader-stroker-fired furnace.
Claim 4
Dependent Claim
15 words
A method as defined in claim 1 wherein the furnace is a fluidized bed combustor.
Claim 5
Dependent Claim
13 words
A method as defined in claim 1 wherein the combustible material comprises coal.
Claim 6
Dependent Claim
21 words
A method as defined in claim 4 wherein the obtained coal particles have a diameter of about 1.5 inches or less.
Claim 7
Dependent Claim
31 words
A method as defined in claim 4 further comprising the step of comminuting the obtained coal particles to a particle size of about 1.5 inches or less before the separating step.
Claim 8
Dependent Claim
21 words
A method as defined in claim 4 wherein the obtained coal particles have a diameter of about 1 inch or less.
Claim 9
Dependent Claim
26 words
A method as defined in claim 4 wherein the separating step comprises separating coal particles smaller than about 0.05 inches in diameter from larger coal particles.
Claim 10
Dependent Claim
26 words
A method as defined in claim 4 wherein the separating step comprises separating coal particles smaller than about 0.1 inches in diameter from larger coal particles.
Claim 11
Dependent Claim
73 words
A method as defined in claim 4 further comprising the step of passing the obtained coal particles through a first screen so as to separate out coal particles larger than about 1.5 inches in diameter and wherein the separating step comprises passing the remaining coal particles having a diameter of about 1.5 inches or less through a second screen so as to separate out coal particles smaller than about 0.05 inches in diameter.
Claim 12
Dependent Claim
40 words
A method as defined in claim 1 wherein the separating step comprises passing the particles of combustible material through a screen so as to separate out the smaller particles which would normally combust in the suspension region of the furnace.
Claim 13
Dependent Claim
22 words
A method as defined in claim 11 wherein the screen comprises a vibrating screen mounted to a conveyor leading to the furnace.
Claim 14
Dependent Claim
13 words
A method as defined in claim 1 wherein the combustible material comprises wood.
Claim 15
Dependent Claim
13 words
A method as defined in claim 1 wherein the combustible material comprises peat.
Claim 16
Dependent Claim
13 words
A method as defined in claim 1 wherein the combustible material comprises char.
Claim 17
Dependent Claim
14 words
A method as defined in claim 1 wherein the combustible material comprises municipal wastes.
Claim 18
Dependent Claim
14 words
A method as defined in claim 1 wherein the combustible material comprises industrial wastes.
Claim 19
Dependent Claim
14 words
A method as defined in claim 1 wherein the combustible material comprises agricultural wastes.
Claim 20
Independent Claim
118 words
A method for reducing NO x and particulate pollutant emissions from a spreader-stoker-fired furnace, the method comprising the steps of: obtaining coal having a particle size of about 1.5 inches or less in diameter; passing coal particles through a screen so as to separate out coal particles smaller than about 0.05 inches in diameter from larger coal particles, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in a suspension region of the spreader-stoker-fired furnace; introducing the larger coal particles, from which coal particles smaller than about 0.05 inches in diameter have been separated, into the suspension region of the spreader-stoker-fired furnace; and combusting the coal particles within the spreader-stoker-fired furnace to produce heat.
Claim 21
Independent Claim
118 words
A method for reducing NO x and particulate pollutant emissions from a spreader-stoker-fired furnace, the method comprising the steps of: obtaining coal having a particle size of about 1.5 inches or less in diameter; passing coal particles through a screen so as to separate out coal particles smaller than about 0.05 inches in diameter from larger coal particles, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in a suspension region of the spreader-stoker-fired furnace; introducing the larger coal particles, from which coal particles smaller than about 0.05 inches in diameter have been separated, into the suspension region of the spreader-stoker-fired furnace; and combusting the coal particles within the spreader-stoker-fired furnace to produce heat.
Claim 22
Dependent Claim
21 words
A method as defined in claim 19 wherein the obtained coal particles have a diameter of about 1 inch or less.
Claim 23
Dependent Claim
33 words
A method as defined in claim 19 wherein the passing step comprises passing the coal particles through a screen so as to separate out coal particles smaller than about 0.1 inches in diameter.
Claim 24
Dependent Claim
23 words
A method as defined in claim 19 wherein the screen comprises a vibrating screen mounted to a conveyor leading to the spreader-stoker-fired furnace.
Claim 25
Dependent Claim
48 words
A method as defined in claim 19 wherein the coal particles having a diameter of about 1.5 inches or less are obtained by passing coal particles of various particle sizes through a screen so as to separate out coal particles having a diameter greater than about 1.5 inches.
Claim 26
Independent Claim
121 words
A method for reducing NO x and particulate pollutant emissions from a spreader-stoker-fired furnace, the method comprising the steps of: obtaining coal having a particle size of about 1 inch or less in diameter; passing the coal particles through a vibrating screen so as to separate out coal particles smaller than about 0.1 inches in diameter from larger coal particles, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in a suspension region of the spreader-stoker-fired furnace; introducing the larger coal particles, from which coal particles smaller than about 0.1 inches in diameter have been separated, into the suspension region of the spreader-stoker-fired furnace; and combusting the larger coal particles within the spreader-stoker-fired furnace to produce heat.
Claim 27
Independent Claim
121 words
A method for reducing NO x and particulate pollutant emissions from a spreader-stoker-fired furnace, the method comprising the steps of: obtaining coal having a particle size of about 1 inch or less in diameter; passing the coal particles through a vibrating screen so as to separate out coal particles smaller than about 0.1 inches in diameter from larger coal particles, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in a suspension region of the spreader-stoker-fired furnace; introducing the larger coal particles, from which coal particles smaller than about 0.1 inches in diameter have been separated, into the suspension region of the spreader-stoker-fired furnace; and combusting the larger coal particles within the spreader-stoker-fired furnace to produce heat.
Claim 28
Independent Claim
109 words
An apparatus for producing heat from a combustible material with reduced NO x and particulate pollutant emissions, comprising: a furnace having a suspension region; means for obtaining a combustible material of variously sized particles; means for separating out smaller particles of combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of combustible material, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in the suspension region of the furnace; and means for introducing the larger particles of combustible material, from which smaller particles of combustible material have been separated, into the suspension region of the furnace.
Claim 29
Independent Claim
109 words
An apparatus for producing heat from a combustible material with reduced NO x and particulate pollutant emissions, comprising: a furnace having a suspension region; means for obtaining a combustible material of variously sized particles; means for separating out smaller particles of combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of combustible material, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in the suspension region of the furnace; and means for introducing the larger particles of combustible material, from which smaller particles of combustible material have been separated, into the suspension region of the furnace.
Claim 30
Dependent Claim
14 words
An apparatus as defined in claim 25 wherein the furnace is a spreader-stoker-fired furnace.
Claim 31
Dependent Claim
15 words
An apparatus as defined in claim 25 wherein the furnace is a fluidized bed combustor.
Claim 32
Dependent Claim
13 words
An apparatus as defined in claim 25 wherein the combustible material comprises coal.
Claim 33
Dependent Claim
23 words
An apparatus as defined in claim 30 wherein the obtained coal has a particle size of about 1.5 inches or less in diameter.
Claim 34
Dependent Claim
25 words
An apparatus as defined in claim 30 wherein the separating means comprises means for separating out coal particles smaller than about 0.05 inches in diameter.
Claim 35
Dependent Claim
42 words
An apparatus as defined in claim 30 wherein the obtained coal has a particle size of about 1 inch or less in diameter and wherein the separating means comprises means for separating out coal particles smaller than about 0.1 inches in diameter.
Claim 36
Dependent Claim
13 words
An apparatus as defined in claim 27 wherein the combustible material comprises wood.
Claim 37
Dependent Claim
14 words
An apparatus as defined in claim 27 wherein the separating means comprises a screen.
Claim 38
Dependent Claim
14 words
An apparatus as defined in claim 35 further comprising means for vibrating the screen.
Claim 39
Independent Claim
124 words
An apparatus for producing heat from coal with reduced NO x and particulate pollutant emissions, comprising: a spreader-stoker-fired furnace; means for obtaining coal in a particle size of about 1 inch or less in diameter; vibrating screen means for separating out coal particles smaller than about 0.1 inches in diameter, thereby leaving coal particles between about 0.1 inches and about 1 inch in diameter, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in a suspension region of the spreader-stoker-fired furnace; and means for introducing the coal particles between about 0.1 inches and about 1 inch in diameter, from which coal particles smaller than about 0.1 inches in diameter have been separated, into the suspension region of the spreader-stoker-fired furnace.
Claim 40
Independent Claim
124 words
An apparatus for producing heat from coal with reduced NO x and particulate pollutant emissions, comprising: a spreader-stoker-fired furnace; means for obtaining coal in a particle size of about 1 inch or less in diameter; vibrating screen means for separating out coal particles smaller than about 0.1 inches in diameter, thereby leaving coal particles between about 0.1 inches and about 1 inch in diameter, thereby minimizing the formation of NO x and particulate pollutant emissions during combustion in a suspension region of the spreader-stoker-fired furnace; and means for introducing the coal particles between about 0.1 inches and about 1 inch in diameter, from which coal particles smaller than about 0.1 inches in diameter have been separated, into the suspension region of the spreader-stoker-fired furnace.
Claim 41
Independent Claim
111 words
A method for reducing pollutant emissions from a furnace having a suspension region, the method comprising the steps of: obtaining a combustible material of variously sized particles; separating smaller particles of the combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of the combustible material; introducing the larger particles of combustible material into the furnace; combusting the larger particles of combustible material within the furnace to produce heat; and placing the smaller separated particles of combustible material directly onto a burning fuel bed within the furnace so as to combust the smaller separated particles of combustible material in the burning fuel bed.
Claim 42
Independent Claim
111 words
A method for reducing pollutant emissions from a furnace having a suspension region, the method comprising the steps of: obtaining a combustible material of variously sized particles; separating smaller particles of the combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of the combustible material; introducing the larger particles of combustible material into the furnace; combusting the larger particles of combustible material within the furnace to produce heat; and placing the smaller separated particles of combustible material directly onto a burning fuel bed within the furnace so as to combust the smaller separated particles of combustible material in the burning fuel bed.
Claim 43
Independent Claim
106 words
A method for reducing pollutant emissions from a spreader-stoker-fired furnace, the method comprising the steps of: obtaining coal having a particle size of about 1.5 inches or less in diameter; passing coal particles through a screen so as to separate out coal particles smaller than about 0.05 inches in diameter from larger coal particles; introducing the larger coal particles into the spreader-stoker-fired furnace; combusting the larger coal particles within the spreader-stoker-fired furnace to produce heat; and placing the separated coal particles smaller than about 0.05 inches in diameter directly onto a burning fuel bed within the spreader-stoker-fired furnace so as to combust the separated coal particles.
Claim 44
Independent Claim
106 words
A method for reducing pollutant emissions from a spreader-stoker-fired furnace, the method comprising the steps of: obtaining coal having a particle size of about 1.5 inches or less in diameter; passing coal particles through a screen so as to separate out coal particles smaller than about 0.05 inches in diameter from larger coal particles; introducing the larger coal particles into the spreader-stoker-fired furnace; combusting the larger coal particles within the spreader-stoker-fired furnace to produce heat; and placing the separated coal particles smaller than about 0.05 inches in diameter directly onto a burning fuel bed within the spreader-stoker-fired furnace so as to combust the separated coal particles.
Claim 45
Independent Claim
90 words
An apparatus for producing heat from a combustible material with reduced pollutant emissions, comprising: a furnace having a suspension region; means for obtaining a combustible material of variously sized particles; means for separating out smaller particles of combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of combustible material; means for introducing the larger particles of combustible material into the furnace; and means for introducing the smaller separated particles of combustible material directly onto a burning fuel bed within the furnace.
Claim 46
Independent Claim
90 words
An apparatus for producing heat from a combustible material with reduced pollutant emissions, comprising: a furnace having a suspension region; means for obtaining a combustible material of variously sized particles; means for separating out smaller particles of combustible material, which would normally combust while suspended within the suspension region of the furnace, from larger particles of combustible material; means for introducing the larger particles of combustible material into the furnace; and means for introducing the smaller separated particles of combustible material directly onto a burning fuel bed within the furnace.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |