EP0225157A2 - Procédé et appareil pour réduire la teneur en NOx dans les gaz d'échappement des fours à charbon - Google Patents

Procédé et appareil pour réduire la teneur en NOx dans les gaz d'échappement des fours à charbon Download PDF

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Publication number
EP0225157A2
EP0225157A2 EP86309192A EP86309192A EP0225157A2 EP 0225157 A2 EP0225157 A2 EP 0225157A2 EP 86309192 A EP86309192 A EP 86309192A EP 86309192 A EP86309192 A EP 86309192A EP 0225157 A2 EP0225157 A2 EP 0225157A2
Authority
EP
European Patent Office
Prior art keywords
fuel
stream
concentrator
mill
coal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP86309192A
Other languages
German (de)
English (en)
Other versions
EP0225157A3 (fr
Inventor
Josef Markstein
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Combustion Australia Ltd
Original Assignee
International Combustion Australia Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Combustion Australia Ltd filed Critical International Combustion Australia Ltd
Priority claimed from AU65732/86A external-priority patent/AU592388B2/en
Publication of EP0225157A2 publication Critical patent/EP0225157A2/fr
Publication of EP0225157A3 publication Critical patent/EP0225157A3/fr
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K3/00—Feeding or distributing of lump or pulverulent fuel to combustion apparatus
    • F23K3/02—Pneumatic feeding arrangements, i.e. by air blast
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C6/00—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
    • F23C6/04—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection
    • F23C6/045—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure
    • F23C6/047—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure with fuel supply in stages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2201/00—Staged combustion
    • F23C2201/10—Furnace staging
    • F23C2201/101—Furnace staging in vertical direction, e.g. alternating lean and rich zones
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2201/00—Staged combustion
    • F23C2201/30—Staged fuel supply
    • F23C2201/301—Staged fuel supply with different fuels in stages
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23K—FEEDING FUEL TO COMBUSTION APPARATUS
    • F23K2201/00—Pretreatment of solid fuel
    • F23K2201/10—Pulverizing

Definitions

  • the present invention relates to a method and apparatus .for reducing the various nitric oxide (NOx) emissions from furnaces.
  • the invention in particular relates to black coal furnaces of the type which are commonly used for generation of electric power.
  • black coal as used herein covers a range of coals including anathraicite, bituminous coals, and lignite. Typically such coals generally have a moisture content less than approximately 30-40%.
  • the coal for such a furnace is pulverized in a mill and the pulverized coal is then entrapped in a primary gaseous transport medium for injection into the furnace.
  • the primary gaseous transport medium is loosely termed "primary air” but in addition to air often includes substantial quantities of flue gas and the like.
  • the mills for such furnaces operate with a ratio of approximatley 30 to 45 cubic feet of primary gaseous transport medium, or primary air, for each pound of the black coal (2 to 3.5 cubic metres air/kg coal).
  • a method of reducing NOx emissions in black coal fired updraught furnaces comprising the steps of entraining pulverized black coal in a primary gaseous transport medium to produce a resulting gaseous flow, separating said resulting gaseous flow into two streams, one fuel rich and one fuel lean, and introducing said streams into said furnace via a corresponding burner or a corresponding set of burners, the burner or set of burners for the fuel lean stream being located at an elevation higher than that of the fuel rich burner or set of burners.
  • the separation is also accompanied by a classification in which oversize particles of coal are extracted from the primary air and returned to the mill.
  • apparatus when used to carry out the above described method, said apparatus comprising a substantially conventional mill and a concentrater located above said mill, said concentrater being arranged to split the primary gaseous transport medium and pulverized fuel mixture from said mill into two streams, the first of which is fuel rich and is introduced into said furnace via a first conduit at a first elevation, and a second of which is fuel lean and is introduced into said furnace via a second conduit located at a second, higher elevation.
  • a concentrator/classifier for connection above the output of a substantially conventional pulverized black coal mill, said concentrator/ classifier comprising a swirl generator means to impart a swirling motion to a stream of primary gaseous transport medium including entrapped pulverized coal particles issuing from said mill, whereby under the action of centrifugal force, the larger of said particles are directed to the outer region of said stream as it passes through an output conduit of said swirl generator means; an opening located in the periphery of said output conduit and leading back to said mill; and a separator means located downstream of said output conduit to divide said stream into a fuel rich stream and a fuel lean stream.
  • the arrangement of the preferred embodiment comprises a substantially conventional mill 1 which is provided with a side entry chute 2 through which black coal drops onto the grinding surfaces of the mill 1.
  • the mill 1 entraps pulverized black coal particles in a stream of primary gaseous transport medium, or "primary air” which is exhausted upwardly into a swirl concentrator 3.
  • the swirl concentrater 3 is formed from a centrally positioned column 4 on which are mounted a set of swirl blades 5 which preferably have a variable pitch.
  • the swirl blades 5 impart a swirling motion to the primary air/pulverized fuel mixture and, under the action of centrifugal forces, the fuel particles are moved outwardly so that the outer portion of the output from the concentrator 3 is fuel rich, whilst the inner portion is lean.
  • annular skimmer slot 6 arranged in the periphery of the outlet of the swirl concentrater 3 which is located a number of vent openings 7. Both the vent openings 7 and skimmer slot 6 communicate with a cylindrical settling chamber 8 which includes a number of guide vanes 9. From the settling chamber 8 a number of return finger shutes 10 are provided, each of which at its lower end has a flap valve 11.
  • the oversized skimmer slot 6 permits oversized fuel particles to pass, under the action of centrifugal forces, into the settling chamber 8 where they drop downwardly under the influence of gravity. In this way, classification takes place so that the oversized fuel particles can be returned to the mill 1 via the return finger chutes 10.
  • Those fine particles of pulverized fuel which may pass through the oversized skimmer slot 6, are returned to the concentrator 3 via the vent openings 7.
  • the number of, and location of, the return finger chutes 10 can be selected in such a manner as to tailor the size and location of the returned components to best suit the configuration of the mill 1.
  • the outer, fuel rich portion passes into a spiral outlet 12 which feeds a first conduit 13 which conducts the fuel rich mixture to multiple burner slots 14 of a black coal updraft furnace 20.
  • the lean primary air/fuel mixture passes into a second conduit 15 and thence into multiple burner slots 16.
  • the second conduit 15 and its associated burner slots 16 lie at an elevation higher than that of the first conduit 13 and its associated burner slots 14.
  • the second conduit 15 is located directly above the first conduit 13.
  • the furnace 20 is substantially conventional and therefore is only schematically illstrated.
  • a central feed chute 17 can be provided instead of the mill 1 having a side entry chute 3.
  • Fig. 3 illustrates the detail of the classifier arrangement of Fig. 1.
  • a skimmer bar 30 scoops the heavy particle carrying component of the swirling primary air and deflects it outwardly into the settling chamber 8.
  • a hood 31 further deflects the oversize. particles downwardly.
  • the gases and not so heavy particles pass over the guide vanes 9 and through the vent openings 7 to return to the primary air.
  • the oversize particles settle within the chamber 8 and fall into the return finger chutes 10.
  • the guide vanes 9 can be rotated about an axis 32 to provide a further mixture control.
  • Figs. 4 to 6 Further classifier embodiments are illustrated in Figs. 4 to 6.
  • the skimmer 130 takes the form of a ring which is secured to both the hood 131 and the fixed guide vanes 191.
  • the skimmer 231 is tilted towards the centre to adjust the size of the skimmer slot.
  • the hood 131 has an adjustable vane 33 to vary the degree of classification by varying the downward momentum of the return material.
  • the remainder of the combustion air termed the secondary air
  • the remainder of the combustion air is fed (in conventional manner) into the furnace 20 through separate ports or wind boxes (not illustrated).
  • Some of the secondary air is fed into the furnace 20 adjacent the burners 14,16.
  • secondary air is fed into the furnace 20 at a location 21 above the upper burner(s) 16. This secondary air is arranged to intersect the fuel stream from the burner slots 14,16 after the volatile matter has been burned. The volatile fraction is thus first liberated and burnt within the limits of the primary air available.
  • the flue gas/char stream is intersected by the secondary air so that the combustion is completed. This delay in the burning of the fraction of the fuel will reduce the Nox emissions to a minimum.
  • the above described arrangement also provides two additional advantages.
  • the first is the flexibility in the selection of operating conditions for the furnace, especially at the minimum low range at which the furnace can operate without the requirement for supporting flame. This arises because the air/fuel ratio of the concentrator output can be maintained at a desired level.
  • the minimum low load able to be supported by a pulverized coal fired furnace (without supporting flame) was dependent upon the minimum air flow at which the mill could operate.
  • the second advantage of the above described arrangement is that the auxiliary power required for the mill and concentrator is substantially reduced because of the classifying action of the apparatus.
  • a conventional double cone classifier there are changes in both direction and velocity of the primary gaseous transport medium which results in a pressure drop in the classifier of approximately 10 to 14 inches water gauge (2.5 to 3.5 kPa).
  • the above described concentrator/classifier because such changes in direction and velocity are avoided, there is a substantially lower pressure drop of the order of approximately 4 inches water gauge (1 kPa).

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
EP86309192A 1985-11-26 1986-11-25 Procédé et appareil pour réduire la teneur en NOx dans les gaz d'échappement des fours à charbon Withdrawn EP0225157A3 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
AUPH358085 1985-11-26
AU3580/85 1985-11-26
AU65732/86A AU592388B2 (en) 1985-11-26 1986-11-26 Concentrator-classifier apparatus for reduced nox emissions from coal furnaces

Publications (2)

Publication Number Publication Date
EP0225157A2 true EP0225157A2 (fr) 1987-06-10
EP0225157A3 EP0225157A3 (fr) 1987-09-30

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ID=25634883

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86309192A Withdrawn EP0225157A3 (fr) 1985-11-26 1986-11-25 Procédé et appareil pour réduire la teneur en NOx dans les gaz d'échappement des fours à charbon

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EP (1) EP0225157A3 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0385499A2 (fr) * 1989-03-03 1990-09-05 Mitsubishi Jukogyo Kabushiki Kaisha Procédé de combustion de charbon pulvérisé
EP0428932A2 (fr) * 1989-11-20 1991-05-29 Mitsubishi Jukogyo Kabushiki Kaisha Procédé de combustion
FR2658589A1 (fr) * 1990-02-20 1991-08-23 Stein Industrie Procede d'alimentation d'un foyer de chaudiere en charbon pulverise et en air, separateur pour la mise en óoeuvre de ce procede, et dispositif d'alimentation en charbon pulverise et en air d'un foyer de chaudiere selon ce procede.
FR2679980A1 (fr) * 1991-08-02 1993-02-05 Stein Industrie Dispositif de chauffe pour les chaudieres a charbon pulverise utilisant la chauffe tangentielle dans le but de reduire les emissions d'oxydes d'azote.
EP0747629A1 (fr) * 1994-12-29 1996-12-11 Maloe Gosudarstvene Vnedrencheskoe Predpriyatie "Politekhenergo" Four a effet vortex a faible emission
CN105387455A (zh) * 2014-09-02 2016-03-09 阿尔斯通技术有限公司 燃烧系统

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB965898A (en) * 1962-07-28 1964-08-06 Babcock & Wilcox Ltd Improvements in apparatus for firing pulverised fuel
FR1591095A (fr) * 1968-09-27 1970-04-27
AU495676B2 (en) * 1974-06-04 1976-12-09 International Combustion Australia Ltd. Improvement of partial separation firing
US4173189A (en) * 1977-01-21 1979-11-06 Combustion Engineering, Inc. Boiler cold start using pulverized coal in ignitor burners
US4238210A (en) * 1979-04-26 1980-12-09 Siegfried Bulang Particle-removal apparatus
DE2933528A1 (de) * 1979-08-18 1981-03-26 Deutsche Babcock AG, 46049 Oberhausen Vorrichtung zum abtrennen von brueden
DE3122476A1 (de) * 1981-06-05 1982-12-23 Ivan Matveevič Dianov Staubtrennvorrichtung
DE3124571A1 (de) * 1981-06-23 1983-06-01 Podol'skij Mašinostroite'lnyj zavod imeni Ordžonikidze, Podol'sk Vorrichtung zum verteilen von brennstoffstaub an kanaele von brennern
JPS58138906A (ja) * 1982-02-15 1983-08-18 Babcock Hitachi Kk 低ＮＯｘ燃焼装置
DE3317244A1 (de) * 1982-07-16 1984-01-26 ORGREB-Institut für Kraftwerke, DDR 7544 Vetschau Verfahren und anordnung zum anfahren benachbarter kohlenstaubgefeuerter dampferzeuger

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB965898A (en) * 1962-07-28 1964-08-06 Babcock & Wilcox Ltd Improvements in apparatus for firing pulverised fuel
FR1591095A (fr) * 1968-09-27 1970-04-27
AU495676B2 (en) * 1974-06-04 1976-12-09 International Combustion Australia Ltd. Improvement of partial separation firing
US4173189A (en) * 1977-01-21 1979-11-06 Combustion Engineering, Inc. Boiler cold start using pulverized coal in ignitor burners
US4238210A (en) * 1979-04-26 1980-12-09 Siegfried Bulang Particle-removal apparatus
DE2933528A1 (de) * 1979-08-18 1981-03-26 Deutsche Babcock AG, 46049 Oberhausen Vorrichtung zum abtrennen von brueden
DE3122476A1 (de) * 1981-06-05 1982-12-23 Ivan Matveevič Dianov Staubtrennvorrichtung
DE3124571A1 (de) * 1981-06-23 1983-06-01 Podol'skij Mašinostroite'lnyj zavod imeni Ordžonikidze, Podol'sk Vorrichtung zum verteilen von brennstoffstaub an kanaele von brennern
JPS58138906A (ja) * 1982-02-15 1983-08-18 Babcock Hitachi Kk 低ＮＯｘ燃焼装置
DE3317244A1 (de) * 1982-07-16 1984-01-26 ORGREB-Institut für Kraftwerke, DDR 7544 Vetschau Verfahren und anordnung zum anfahren benachbarter kohlenstaubgefeuerter dampferzeuger

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, vol. 7, no. 254 (M-255)[1399], 11th November 1983; & JP-A-58 138 906 (BABCOCK HITACHI K.K.) 18-08-1983 *
REVUE GENERALE DE THERMIQUE, vol. 12, no. 144, December 1973, pages 1255-1262, Paris, FR; D.L. PAPADIAS: "L'utilisation des lignite et tourbe grecs pour la production de vapeur" *

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0385499A2 (fr) * 1989-03-03 1990-09-05 Mitsubishi Jukogyo Kabushiki Kaisha Procédé de combustion de charbon pulvérisé
EP0385499A3 (fr) * 1989-03-03 1991-05-22 Mitsubishi Jukogyo Kabushiki Kaisha Procédé de combustion de charbon pulvérisé
EP0428932A2 (fr) * 1989-11-20 1991-05-29 Mitsubishi Jukogyo Kabushiki Kaisha Procédé de combustion
EP0428932A3 (en) * 1989-11-20 1991-10-09 Mitsubishi Jukogyo Kabushiki Kaisha Boiler
US5429060A (en) * 1989-11-20 1995-07-04 Mitsubishi Jukogyo Kabushiki Kaisha Apparatus for use in burning pulverized fuel
FR2658589A1 (fr) * 1990-02-20 1991-08-23 Stein Industrie Procede d'alimentation d'un foyer de chaudiere en charbon pulverise et en air, separateur pour la mise en óoeuvre de ce procede, et dispositif d'alimentation en charbon pulverise et en air d'un foyer de chaudiere selon ce procede.
FR2679980A1 (fr) * 1991-08-02 1993-02-05 Stein Industrie Dispositif de chauffe pour les chaudieres a charbon pulverise utilisant la chauffe tangentielle dans le but de reduire les emissions d'oxydes d'azote.
EP0747629A1 (fr) * 1994-12-29 1996-12-11 Maloe Gosudarstvene Vnedrencheskoe Predpriyatie "Politekhenergo" Four a effet vortex a faible emission
EP0747629A4 (fr) * 1994-12-29 1997-12-10 Maloe G Vnedrencheskoe Predpr Four a effet vortex a faible emission
CN105387455A (zh) * 2014-09-02 2016-03-09 阿尔斯通技术有限公司 燃烧系统
EP2993400A1 (fr) * 2014-09-02 2016-03-09 Alstom Technology Ltd Système de combustion
US10012382B2 (en) 2014-09-02 2018-07-03 General Electric Technology Gmbh Combustion system

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Publication number Publication date
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