EP0950853A2 - Brûleurs à prémélange combustible/air - Google Patents

Brûleurs à prémélange combustible/air Download PDF

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Publication number
EP0950853A2
EP0950853A2 EP99107675A EP99107675A EP0950853A2 EP 0950853 A2 EP0950853 A2 EP 0950853A2 EP 99107675 A EP99107675 A EP 99107675A EP 99107675 A EP99107675 A EP 99107675A EP 0950853 A2 EP0950853 A2 EP 0950853A2
Authority
EP
European Patent Office
Prior art keywords
gas
stack
interior
protrusions
gas burner
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.)
Ceased
Application number
EP99107675A
Other languages
German (de)
English (en)
Other versions
EP0950853A3 (fr
Inventor
Graham c/o Bray Technologies PLC Wood
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.)
BRAY TECHNOLOGIES PLC
Original Assignee
BRAY TECHNOLOGIES PLC
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 BRAY TECHNOLOGIES PLC filed Critical BRAY TECHNOLOGIES PLC
Publication of EP0950853A2 publication Critical patent/EP0950853A2/fr
Publication of EP0950853A3 publication Critical patent/EP0950853A3/fr
Ceased legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/02—Premix gas burners, i.e. in which gaseous fuel is mixed with combustion air upstream of the combustion zone
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/34—Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air
    • F23D14/36—Burners specially adapted for use with means for pressurising the gaseous fuel or the combustion air in which the compressor and burner form a single unit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/10—Flame diffusing means
    • F23D2203/101—Flame diffusing means characterised by surface shape
    • F23D2203/1012—Flame diffusing means characterised by surface shape tubular
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/10—Flame diffusing means
    • F23D2203/108—Flame diffusing means with stacked sheets or strips forming the outlets
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2210/00—Noise abatement
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
    • F23D2900/00003—Fuel or fuel-air mixtures flow distribution devices upstream of the outlet

Definitions

  • This invention relates to pre-mixed burners which are used for example in water heating boilers and other heating devices.
  • Certain burners are called fully pre-mixed because the fuel, usually gas, and a quantity of air equal to or exceeding the stoichiometrically correct amount of air to support the combustion of the fuel, are supplied and are mixed to produce a combustible mixture which subsequently is ignited to produce a burner flame which, in the case of heating the water in a boiler, is applied to a heat exchanger of the boiler.
  • the term pre-mixed arises therefore because of the mixing of the fuel and air before the ignition.
  • burners which operate in a mode in which a sub-stoichiometric amount of primary combustion air is mixed with the fuel before ignition, and secondary air, required for completing the combustion process, is supplied to, or more usually induced into, the flame after ignition of the fuel/primary air mixture.
  • These other burners are known as partially pre-mixed burners.
  • the present invention may be applicable to such burners, but its best application is to the fully pre-mixed type, as partially pre-mixed burners are being used less and less because they are rather inefficient and generate high levels of nitrogen oxides (NOx) during the combustion process.
  • NOx nitrogen oxides
  • the present invention is concerned with a burner of the type adapted to fit inside the boiler heat exchanger, the latter being of a generally cylindrical construction with the water pipes defining the generally cylindrical construction. Accordingly, although not strictly necessary, the burner will be of a generally cylindrical construction, to ensure that the flame which exists around the circumference of the burner will be applied evenly to the water tubes for the heating of the water therein.
  • Boilers having cylindrical heat exchangers are becoming more popular as heat transfer to water or air is required to become more efficient, and more particularly the use of such a construction enables the boiler to be located in less space, which is always desirable. Also, as boiler efficiencies and range of operation increases, many boilers now are condensing boilers, which means that so much of the available heat is extracted from the combustion products, that there is generated a considerable amount of condensation, which must be collected and disposed of. Boilers with the cylindrical heat exchangers enable that to be done effectively.
  • German Utility Model Application No. DE19704985 to Vaillant describes such a cylindrical burner being essentially comprised of a plurality of superposed metal discs which are provided with radial formations on their surfaces which when contiguous with corresponding radial formations on adjacent discs define gas mixing channels therebetween. Additionally, the metal discs are annular and when clamped together define an inner cavity of the burner into which the fuel-air mixture is introduced before being urged through said gas mixing channels which emerge on the outer surface of the burner.
  • the present invention is concerned with a burner which is adapted to be used in a boiler which has a generally cylindrical heat exchanger (such boilers are also known as boilers with "wrap round” or axi-symmetric heat exchangers), but wherein the burner is constructed so as not to suffer the problem which is present in the prior art arrangement discussed above.
  • the fuel/air mixture will be gas and air, but it is again possible, although unusual, to use a liquid fuel/air mixture.
  • the fuel/air mixture will be gas and air, but it is again possible, although unusual, to use a liquid fuel/air mixture.
  • a gas burner comprising a plurality of annular plate elements stacked to form at least a part of the burner body and to define therein a hollow interior, said interior being adapted to receive a combustible gas/air mixture supplied through one end of the stack, the stack defining a plurality of passages which lead in a direction transverse to the stack height from the interior to flame ports on the outside of the body, characterised in that the plate elements are provided with a plurality of protrusions on one surface having gaps therebetween, said protrusions cooperating with the surface of an adjacent element to at least partially define the flame ports, and in that the protrusions separate adjacent plate elements from one another.
  • the plate elements are substantially planar on one suraface.
  • the protrusions are disposed substantially annularly on one surface of the element.
  • the substantially planar surface of the element is provided with recesses which can receive the protrusions of an adjacent element to correctly orientate adjacent plate elements with respect to one another.
  • the depth of the recesses is less than the height of the protrusions so as to provide a separation distance between adjacent plate elements and define the transverse passages and/or the flame ports through which the gas/air mixture can flow.
  • the plate elements preferably are made of heat resistant ceramic material, and the plate elements may be pressings, castings (preferably freeze castings) or machined items.
  • the passages may be defined jointly by adjacent elements when they are stacked.
  • the plate elements which may be identical for ease of production, may have feet on one side and recesses on the other side, in which the feet of the adjacent element sit, but the feet being of a length greater than the depth of the recesses, so that the elements are stacked but spaced one relative to the other, so that the passages are formed therebetween.
  • the number of feet may be varied to vary the size and number of the passages and flame ports.
  • the stack may be closed, by a closure cap, and the elements may be held together in any suitable manner, for example by using a through bolt arrangement of the type set forth in the said European Application.
  • the elements are preferably circular in shape, so that the stack outer surface is circular, whereby a cylindrical flame is established when the burner is in use. Such a flame in practice will be short, with low emission of NOX.
  • the use of ceramic material for the elements means that the elements will withstand higher surface temperatures than metals, permitting higher turndown ranges of operation, and also lower primary aeration, enabling higher thermal efficiencies.
  • the burner is preferably fan powered for the supply of air for the combustible mixture.
  • edges of the elements preferably are shaped or profiled to eliminate eddy current shedding from the gas/air mixture at the port edge and minimize combustion resonance, as set forth in our copending European Application No. 0810404 A2.
  • the interior of the body may include a distributor, to ensure that the gas/air mixture is evenly distributed throughout the length of the stack, so that as far as possible, even amounts of gas/air mixture reach all of the passages and flame ports throughout the height of the stack.
  • a distributor may comprise a perforated metal tube having an open end and a closed end, the open end being located at the end at which the gas/air mixture is supplied to the interior, so the mixture is initially supplied to the inside of the distributor tube, from whence it emerges into the interior of the body before being forced through the passages to the flame ports.
  • effective gaseous distribution may be achieved by providing protrusions on a surface of the element around annuli thereon of two different radii such that the protrusions disposed in the annulus of greater radius at least partially define the flame ports on one side and define a substantially annular gas distribution channel with the protrusions disposed in the annulus of lesser radius.
  • Effective gaseous distribution may be also achieved by staggering the protrusions of one annulus relative to the other, or by varying the size of the gaps between the protrusions disposed in one or other of the annuli.
  • the gaps between the protrusions disposed in the annulus of lesser radius are larger than those disposed in the annulus of greater radius.
  • a burner 10 which is a cylindrical assembly having its axis centered on holding bolt 12.
  • the assembly is made up of a plurality of plate elements 14 of identical construction, these elements being flat discs and being annular in nature so that the holes in the center of the plates together form a burner interior 16. That interior 16 is shown in Fig. 1 and is closed at one end by means of a cap 18, whilst at the other end the interior is opened to the supply of a fuel air mixture as indicated by arrows 20, from a powered fan 22.
  • a distributor cylinder 24 which may be metallic in nature, and it is closed at the opposite end of the burner as indicated by reference 26, but the wall is perforated as indicated by reference 28 so that the fuel air mixture 20 is initially pumped into the distributor 24, and escapes through the perforations 28 so as to be evenly distributed throughout the interior 16 of the assembly of plate 14.
  • the plates 14 as shown in Fig. 2 are provided with feet 30 on one side, whilst on the other side they have recesses to receive the basis of the feet of an adjacent plate element 14.
  • the feet are longer than the depth of the recesses so that there are established passages 32 extending between the elements 14 radially outwards to the exterior surface of the assembly of plate elements 14, whereat they form flame ports 34.
  • Increasing or decreasing the differential also increases and decreases the size of the flame ports.
  • the gas air mixture issuing from these flame ports is ignited so as to form the flames 36.
  • a coupling plate 42 may be provided through which the bolt 12 passes, and which has quadrant shaped apertures 44 to enable the fuel air mixture to pass into the distributor 24.
  • the passage of the gas/air mixture through said apertures also has a beneficial effect on the mixing.
  • the burner 10 forms a neat cylindrical assembly around the cylindrical outer wall of which the annular flame 36 is established. As explained herein, such a burner is effective in providing heat for a cylindrical type heat exchanger of the type which is being used more and more in practice.
  • the dimensions of the plate elements 14, and feet 30 and the recesses of which they are received will be selected so as to provide passages 32 of the appropriate dimension for effective combustion, and, as shown in Fig. 4, the outer peripheral edges of the plate elements 14 may be profiled as shown at 46 in order to mitigate against any current shedding, and to minimize resonant noise, as referred to herein.
  • the profile in 46 in the example of Fig. 4 is the tapering of the extreme edges to a pointed configuration.
  • the distributor 24 provides a means whereby the fuel air mixture may be evenly distributed throughout the interior 16, to ensure that equal amounts of fuel and air mixture pass through all of the passages 32, but in alternative arrangements, the same effect can be achieved in a different way.
  • the plate elements 14 are not identical, but are arranged so that progressively from top to bottom of the stack, the passages 32 are of progressively increasing cross-sectional area so that the pressure of the fuel air mixture in the respective passages will tend to be automatically equalized and equal amounts will flow from the ports 36 without the use of the distributor.
  • a solid inverted cone 50 is connected to the underside of the cover 18, so as to create a pressure gradient inside the interior 16 which will have the effect of causing equal amounts of fuel air mixture to be expelled through the passages 32, without the use of perforated distributor.
  • the cone and the top cap may be cast in one piece as a single element.
  • the essential feature of the present invention is the utilization of stacked plate elements, preferably of a ceramic material, or the distribution outwardly and transversely of the stack height of the fuel air mixture so as to establish a peripheral burner flame which can be applied to the heat exchange tubes in a cylindrical type heat exchanger.
  • FIG. 7 there is shown an alternative embodiment of plate element 100 having protrusions 102 disposed substantially annularly on a surface 106 of said plate clement.
  • the annulus around which said protrusions 102 are disposed is shown in dotted line and has a mean radius R 1
  • protrusions 104 are disposed within a second annulus disposed on the surface 106 and having a means radius R 2 . It is immediately evident from the Figure that R 2 >R 1 .
  • gaps between the protrusions around the respective annulus in which they are disposed is shown in the Figure as being large for the purposes of clarity. In practice the gaps between protrusions in either annulus will be much smaller that the protrusions themselves such that the gas flow therethrough is to some extent restricted.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Gas Burners (AREA)
EP99107675A 1998-04-18 1999-04-16 Brûleurs à prémélange combustible/air Ceased EP0950853A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GBGB9808354.6A GB9808354D0 (en) 1998-04-18 1998-04-18 Improvements relating to fuel/air pre-mixed burners
GB9808354 1998-04-18

Publications (2)

Publication Number Publication Date
EP0950853A2 true EP0950853A2 (fr) 1999-10-20
EP0950853A3 EP0950853A3 (fr) 2000-02-23

Family

ID=10830630

Family Applications (1)

Application Number Title Priority Date Filing Date
EP99107675A Ceased EP0950853A3 (fr) 1998-04-18 1999-04-16 Brûleurs à prémélange combustible/air

Country Status (2)

Country Link
EP (1) EP0950853A3 (fr)
GB (1) GB9808354D0 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1096203A1 (fr) * 1999-10-29 2001-05-02 Centre d'Etude et de Réalisation d'Equipement et de Matériel (CEREM) Emetteur de chauffage à rayonnement infrarouge au gaz
WO2004031651A3 (fr) * 2002-10-01 2005-01-20 Powertech Ind Inc Chambre de combustion a plaques multiples
WO2009065733A1 (fr) 2007-11-19 2009-05-28 Sit La Precisa S.P.A. Con Socio Unico Brûleur, en particulier brûleur à prémélange
CN103062749A (zh) * 2013-01-29 2013-04-24 山西省第二建筑工程公司 提高燃气锅炉热效率的方法
WO2013120716A1 (fr) * 2012-02-16 2013-08-22 Bekaert Combustion Technology B.V. Brûleur à gaz à prémélange
CN103591586A (zh) * 2013-05-20 2014-02-19 洛阳疋姆泰可精密零件制造有限公司 一种燃气混合器
CN110345516A (zh) * 2018-04-03 2019-10-18 刘旭男 炉具与应用于炉具的焰口结构及其制造方法
US11378273B2 (en) * 2017-01-11 2022-07-05 A. O. Smith Corporation Reduced resonance burner

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19704985A1 (de) 1996-01-30 1997-07-31 Vaillant Joh Gmbh & Co Heizeinrichtung
EP0810404A2 (fr) 1996-05-30 1997-12-03 Bray Burners Limited Brûleur à prémélange combustible/air complet
EP0816757A2 (fr) 1996-07-05 1998-01-07 Schwank GmbH Elément de brûleur

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2625994A (en) * 1946-01-09 1953-01-20 Allis Chalmers Mfg Co Gas burner formed by stacked annular members
FR1527971A (fr) * 1967-04-14 1968-06-07 Colombel Freres Ets Brûleur extra plat pour gaz basse pression
FR2481415A1 (fr) * 1980-04-23 1981-10-30 Fulpin Jacques Bruleur a gaz
WO1984001205A1 (fr) * 1982-09-16 1984-03-29 Mc Gill Inc Bruleur a paroi radiante
US5002038A (en) * 1989-12-12 1991-03-26 Robert Shaw Controls Company Burner construction and method of making the same
US5022352A (en) * 1990-05-31 1991-06-11 Mor-Flo Industries, Inc. Burner for forced draft controlled mixture heating system using a closed combustion chamber
DE29504255U1 (de) * 1995-03-11 1996-07-11 Robert Bosch Gmbh, 70469 Stuttgart Heizgerät, insbesondere für Wassererhitzer

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19704985A1 (de) 1996-01-30 1997-07-31 Vaillant Joh Gmbh & Co Heizeinrichtung
EP0810404A2 (fr) 1996-05-30 1997-12-03 Bray Burners Limited Brûleur à prémélange combustible/air complet
EP0816757A2 (fr) 1996-07-05 1998-01-07 Schwank GmbH Elément de brûleur

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1096203A1 (fr) * 1999-10-29 2001-05-02 Centre d'Etude et de Réalisation d'Equipement et de Matériel (CEREM) Emetteur de chauffage à rayonnement infrarouge au gaz
US6461150B1 (en) 1999-10-29 2002-10-08 Centre D'etude Et De Realisation D'equipment Et De Materiel (Cerem) Very low pressure gas-fired overhead radiant heater with atmospheric primary air supply by means of a venturi
US6612834B2 (en) 1999-10-29 2003-09-02 Centre D'etude Et De Realisation D'equipment Et De Materiel Very low pressure gas-fired overhead radiant heater with atmospheric primary air supply by means of a venturi
CN100532934C (zh) * 2002-10-01 2009-08-26 法马控股有限公司 多板式燃烧器
US7473094B2 (en) 2002-10-01 2009-01-06 Fama Holdings Ltd. Multiple plate combustor
WO2004031651A3 (fr) * 2002-10-01 2005-01-20 Powertech Ind Inc Chambre de combustion a plaques multiples
WO2009065733A1 (fr) 2007-11-19 2009-05-28 Sit La Precisa S.P.A. Con Socio Unico Brûleur, en particulier brûleur à prémélange
WO2013120716A1 (fr) * 2012-02-16 2013-08-22 Bekaert Combustion Technology B.V. Brûleur à gaz à prémélange
CN103062749A (zh) * 2013-01-29 2013-04-24 山西省第二建筑工程公司 提高燃气锅炉热效率的方法
CN103591586A (zh) * 2013-05-20 2014-02-19 洛阳疋姆泰可精密零件制造有限公司 一种燃气混合器
US11378273B2 (en) * 2017-01-11 2022-07-05 A. O. Smith Corporation Reduced resonance burner
CN110345516A (zh) * 2018-04-03 2019-10-18 刘旭男 炉具与应用于炉具的焰口结构及其制造方法
CN110345516B (zh) * 2018-04-03 2020-11-06 刘旭男 炉具与应用于炉具的焰口结构及其制造方法

Also Published As

Publication number Publication date
GB9808354D0 (en) 1998-06-17
EP0950853A3 (fr) 2000-02-23

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