EP0465679B1 - Brenner mit oberflächenverbrennung - Google Patents

Brenner mit oberflächenverbrennung Download PDF

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Publication number
EP0465679B1
EP0465679B1 EP91903697A EP91903697A EP0465679B1 EP 0465679 B1 EP0465679 B1 EP 0465679B1 EP 91903697 A EP91903697 A EP 91903697A EP 91903697 A EP91903697 A EP 91903697A EP 0465679 B1 EP0465679 B1 EP 0465679B1
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EP
European Patent Office
Prior art keywords
layer
burner
stainless steel
combustion
combustion 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.)
Expired - Lifetime
Application number
EP91903697A
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English (en)
French (fr)
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EP0465679A4 (en
EP0465679A1 (de
Inventor
Sunao Nakamura
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.)
JFE Engineering Corp
Original Assignee
Nippon Kokan Ltd
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Filing date
Publication date
Application filed by Nippon Kokan Ltd filed Critical Nippon Kokan Ltd
Publication of EP0465679A1 publication Critical patent/EP0465679A1/de
Publication of EP0465679A4 publication Critical patent/EP0465679A4/en
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Publication of EP0465679B1 publication Critical patent/EP0465679B1/de
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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
    • F23D14/12—Radiant burners
    • F23D14/18—Radiant burners using catalysis for flameless combustion
    • 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
    • F23D14/12—Radiant burners
    • F23D14/16—Radiant burners using permeable blocks
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/10—Flame diffusing means
    • F23D2203/106—Assemblies of different layers

Definitions

  • the present invention relates to a surface combustion burner and more particularly to a surface combustion burner of a plural layer structure which is constructed by laminating a layer of a burning resisting material such as a ceramic material for forming a gas combustion zone and a supporting layer such as a metal fiber mat.
  • a burning resisting material such as a ceramic material for forming a gas combustion zone
  • a supporting layer such as a metal fiber mat.
  • a surface combustion burner is known as one of techniques which employ as a heat source thereof a gas fuel that is low in cost and high in calory.
  • the surface combustion burner is such that the heat energy of a combustion gas, which is largely taken out by convection in the case of the ordinary combustion, is efficiently converted to a radiant heat and it is designed so that a mixture or a premix of air and a gas fuel is supplied from one side of a permeable sheet member ( hereinafter referred to as a burner diaphragm ) and the mixture is burned in the surface layer portion on the other side of the burner diaphragm, thus heating the surface layer portion itself of the burner diaphragm and thereby causing it to discharge the radiant heat.
  • a permeable sheet member hereinafter referred to as a burner diaphragm
  • the combustion of the gas is maintained in a condition where a flame is brought into close contact with the surface of the burner diaphragm or entered into the surface layer portion and the radiant heat is radiated from the flame and the burner diaphragm surface layer portion heated to a red hot state.
  • the burner diaphragm composed of a mat made by sintering stainless steel fibers can be formed to have a complicated surface shape and its strength is excellent and since the realization of a high-porosity structure makes it possible to easily manufacture a burner which is large in area, low in pressure loss, high in combustion degree and high in power output density and which is relatively inexpensive, its application to such uses as a heating apparatus at an outdoor job site and the baking and drying of automobile painting is expected.
  • Fig. 3 is a schematic diagram showing the construction of an infrared heater used at an outdoor job site as an example of a surface combustion burner apparatus using a burner diaphragm made of a stainless steel fiber mat, and its principal part including the burner diaphragm is shown in section.
  • the burner diaphragm m is composed of a stainless steel fiber mat of 5 mm thick which is made by forming stainless steel ( JIS-SUS 316 ) long fibers of 20 ⁇ m in diameter and about 50 mm in length into a mat shape and sintering the long fibers together.
  • this burner diaphragm m its surface layer portion ml forms a gas combustion zone during the operation of the apparatus and this gas combustion zone is a radiant heat radiation portion.
  • a fuel gas supply system including a gas nozzle N, a solenoid valve SV and a fuel gas bomb T and an air supply system including an air blower or fan F are connected to a burner proper K to which the burner diaphragm m is attached.
  • a spark electrode S for ignition purposes is arranged in opposition to the lower end of the burner diaphragm m so that when its switch is operated, a controller C not only brings the solenoid valve SV and the blower F into operation but also applies a spike-like high voltage between the spark electrode S and the burner diaphragm m thus producing a discharge spark and thereby igniting the gas-air mixture at the surface of the burner diaphragm m .
  • These component members are mounted on a movable base B which is equipped with wheels.
  • the solenoid valve SV is opened causing the injection of the fuel gas through the nozzle N and also the blower F is started thus supplying air whereby inside the burner proper K the resulting mixture of the fuel gas and the air flows toward and passes through the burner diaphragm m thereby soaking out to the outside through the surface layer portion ml.
  • a spark is produced between the spark electrode S and the burner diaphragm m across which a high voltage has been applied so that the air-gas mixture soaking out to this portion is ignited and a flame is rapidly propagated all over the surface of the burner diaphragm m thereby starting the burning operation.
  • the amount of gas supply and the amount of air supply must be controlled exactly.
  • the ratio of the amount of gas supply to the amount of air supply (the mixture ratio ) is made substantially equivalent to a chemical reaction stoichiometric amount ratio and also the flow rate of the gas-air mixture passing through the burner diaphragm m is selected to be in such a range that the flame does not get off the surface of the burner diaphragm m .
  • the stable combustion is maintained in the surface layer portion ml of the burner diaphragm m and the surface layer portion ml is heated red hot, thereby radiating a radiant heat in an amount substantially dependent on the surface temperature of the surface layer portion m1.
  • the progress in the oxidation deterioration of the burner diaphragm surface layer portion heated red hot is so remarkable that the stainless steel fiber mat is rapidly thinned out thus leading to breaking and the life of the burner diaphragm is decreased; therefore, as for example, in the case of the burner diaphragm m of the conventional heater, the life has never exceeded 100 hours even in the ordinary operation.
  • Fig. 4 shows a temperature distribution in the thickness direction of the burner diaphragm m when the conventional surface combustion burner performed the ordinary operation.
  • the abscissa represents the internal depth position D[mm] of the burner diaphragm m with the surface of the surface layer portion ml as the origin (0) and the ordinate represents the temperature T[°C].
  • the temperature at the surface of the surface layer portion ml of the burner diaphragm m is as high as about 1200°C and this is a severe environment for this kind of stainless steel fiber mat whose normal temperature is desired to be maintained lower than about 800°C.
  • the stainless steel fiber mat itself is a material which is relatively low in heat conductivity and it is always cooled by the unburned gas-air mixture passing therethrough, as the position becomes closer to the back side from the surface layer portion ml, the temperature is decreased rapidly so that even in Fig. 4 the temperature is in fact below 800°C at the internal position of only 1 mm from the surface of the surface layer portion ml and here the temperature is such that it is satisfactorily withstood by the stainless steel fiber mat.
  • a burner diaphragm of a two-layer structure by replacing the surface layer portion ml of the burner diaphragm m with a mat of a heat resisting material, e.g., a sintered burning resisting material such as Al 2 O 3 ceramic fibers, using the remainder, i.e., the back side excluding the surface layer portion as a supporting layer for the stainless steel fiber mat and bonding the heat resisting material mat and the stainless steel fiber mat together by sintering.
  • a heat resisting material e.g., a sintered burning resisting material such as Al 2 O 3 ceramic fibers
  • the stainless steel fibers and the heat resisting material fibers differ considerably with respect to the essential conditions for sintering, that is, the stainless steel fibers will be melted under the required temperature condition for the sintering of the heat resisting material fibers and so on and thus it is now apparent that it is difficult to bond the two mats by sintering.
  • GB-A-1,368,084 discloses a surface combustion burner comprising one or two layers of hand deformable ceramic fibre cloth, backed by a hand deformable ceramic fibre blanket. The clotch layer or layers and the blanket are held together by individual loops anchored in a layer of a wire mesh sheet. Further, the mesh sheet is backed by a hard deformable foamed metal serving as a flame trap.
  • the invention aims to provide an improved surface combustion burner, in particular a surface combustion burner having a long life, which is so designed that the heat resistance of a burner diaphragm is enhanced by making its surface layer portion with a burning resisting material, and the layer of the burning resisting material and a layer of stainless steel fiber mat are firmly bonded without deteriorating the uniformity of gas combustion at the combustion surface.
  • a surface combustion burner according to a basic concept of the present invention is defined in claim 1.
  • the burning resisting thread is composed of a heat resisting metal wire, and the first and third are sewed on with stitches made with the heat resisting metal wire by a sewing machine.
  • a mixture prepared by premixing air and a gas is supplied from the second layer side so that the mixture passes through the second layer, soaks out to the first layer and is burned in the surface layer portion or the first layer, thereby heating the surface layer portion to a red-hot state.
  • the first and third layers are bonded together by sewing and the second layer is bonded to the third layer by sintering, thereby firmly bonding the three layers to one another.
  • the third layer is made of a material, i.e., the same stainless steel material that can be easily sintered with the second layer so that after the third layer has been sewed on the first layer, the second layer is superposed on the third layer and bonded together by sintering.
  • the first layer has a certain thickness and the second and third layers are apart from the high-temperature combustion surface by a distance corresponding to the thickness of the first layer, thereby preventing them from being directly exposed to an elevated temperature due to the gas combustion. Also, since the second and third layers are bonded by sintering, there are no holes and heat resisting material extending through the burner diaphragm and therefore the uniformity of the flow rate and the combustion condition of the air-gas mixture at its combustion surface is maintained.
  • a burning resisting material e.g., heat resisting metal wires such as a Kanthal wire of Fe-25%, Cr-5% and Al-2% Co or a twisted thread or single-strand thread of a ceramic fiber material
  • the thickness of these threads shoud preferably be selected to meet the minimum required limit in terms of strength from the standpoint of making the combustion condition uniform.
  • the first layer made of a ceramic cloth is easy to handle as compared with a ceramic fiber mat or the like and moreover there is no occurrence of any crushing or collapsing due to the sewing, thereby making it possible to join the first and third layers together by using for example the ordinary industrial sewing machine or the like.
  • the burner diaphragm surface layer forming its gas combustion zone is formed by the first layer of the burning resisting material and thereform the progress of oxidation deterioration of the burner diaphragm is retarded. Also, since the first layer is sewed on the third layer and the third layer is firmly bonded to the second layer by sintering, the burner diaphragm and the surface combustion burner can be manufactured and handled easily and there is less danger of causing nonuniformity of the combustion at the combustion surface due to the sewing and hence the occurrence of a partial oxidation deterioration phenomenon due to such nonuniform combustion. As a result, the life of the burner diaphragm is increased, thus making it possible to improve the utilization of the burner diaphragm and thereby to reduce the operating cost of a combustion apparatus using this burner diaphragm.
  • the selection of materials can be made with a considerable freedom without giving any consideration to the difference in sintering temperature and the matching as to affinity, etc., between the materials as in the case of the bonding by sintering.
  • Fig. 1a is a front view showing the construction of a surface combustion burner according to an embodiment of the present invention.
  • Fig. 1b is a partial enlarged sectional view of Fig. 1a.
  • Fig. 2 is a graph showing the relation between the operating condition of the surface combustion burner according to the embodiment of the present invention and the boundary surface temperatures of the respective layers in the burner diaphragm, with the abscissa representing the equivalent amount ratio ⁇ ( actual fuel-air ratio/stoichiometric fuel-air ratio ) and the ordinate representing the temperature T[°C].
  • Fig. 3 is a schematic diagram showing an example of the construction of a heating apparatus for outdoor operation purposes by way of an example of the applications of a conventional surface combustion burner.
  • Fig. 4 is a graph showing a temperature distribution at the section of the stainless steel fiber mat in the conventional surface combustion burner, with the abscissa representing the internal depth position D[mm] of the burner diaphragm using the surface of the surface layer portion as the origin (0) and the ordinate representing the temperature T[°C].
  • the surface combustion burner according to this embodiment includes a burner diaphragm M of a three-layer structure including an Al 2 O 3 ceramic cloth 1 as a first layer which is to form a surface layer portion, a stainless steel fiber mat 3 as a second layer which is to form a supporting layer, and a stainless steel fiber mat 2 as a third layer which is to be interposed between the first and second layers to effect the bonding between the two layers through it.
  • the ceramic cloth 1 forming the first layer and the stainless steel fiber mat 2 forming the third layer are sewed together with a Kanthal single-strand wire 4 as will be described in detail later, and the second and third layers are bonded together through the sintering of the stailess steel fiber mats 2 and 3 of the same material.
  • the first layer or the Al 2 O 3 ceramic cloth 1 is a nonwoven cloth of 1 to 2 mm thick which is made of Al 2 O 3 long fibers of 8 ⁇ m in diameter
  • the second and third layers or the stainless steel fiber mats 2 and 3 are each made by combining and forming a large number of stainless steel ( JIS-SUS 316 ) fibers of 20 ⁇ m in diameter and about 50 mm in length into a mat shape and then bonding the long fibers together by sintering, with the mat 3 having a thickness of 4 mm and the mat 2 having a thickness of 0.5 mm.
  • the Al 2 O 3 ceramic cloth 1 and the stainless steel fiber mats 2 and 3 have substantially the same porosity of 90% or over.
  • the Al 2 O 3 ceramic cloth 1 of 1 to 2 mm thick and the stainless steel fiber mat 2 of 0.5 mm thick are arranged one upon another so that the superposed two layers are sewed crosswise according to a checkerboard-like stitch pattern of about 10 mm squares with the single-strand wire of Kanthal, an iron-chromium alloy or the like, of 0.1 mm in diameter by an industrial sewing machine thereby bonding the two layers together; thereafter, the stainless steel fiber mat 3 of 4 mm thick is superposed on the stainless steel fiber mat 2 and the boundary surface portion of the mats 2 and 3 is sintered under the application of a pressure in a high temperature condition, thereby bonding the two together.
  • Fig. 2 shows the relation between the equivalent amount ratio ⁇ of the gas-air mixture (the actual fuel-air ratio/ the stoichiometric fuel-air ratio ) in the surface combustion burner of the present embodiment and the boundary surface temperatures of the respective layers in the burner diaphragm M.
  • the typical flow velocity of the mixture is selected to be 15 cm/sec and methane (CH 4 ) is selected as the fuel gas.
  • the curve Tms represents the surface temperature of the Al 2 O 3 ceramic cloth 1, the curve Tmb the temperature at the back of the Al 2 O 3 ceramic cloth 1 or the temperature at the boundary surface between it and the stainless steel fiber mat 2, and Tmd the temperature at the boundary surface between the stainless steel fiber mats 2 and 3.
  • the temperature at the boundary surface between the Al 2 O 3 ceramic cloth 1 and the stainless steel fiber mat 2 can be maintained below 800°C with respect to the various equivalent amount ratios ⁇ and also the temperature at the boundary surface between the stainless steel fiber mats 2 and 3 can be maintained below about 600°C.
  • the progress of oxidation in the stainless steel fiber mats 2 and 3 is retarded so that in accordance with the present embodiment the burner diaphragm life can be increased up to 5000 hours even under the maximum load operation as compared with the conventional life of about 100 hours, whereas, even if the stitch pattern due to the sewing of the Al 2 O 3 ceramic cloth 1 and the stainless steel fiber mat 2 is simply present at the combustion surface, the stainless steel fiber mats 2 and 3 are bonded by sintering so that there is no occurrence of the breaking out of a flame on the stitch pattern at the combustion surface during the operation and the uniformity of the surface combustion is improved.
  • the stainless steel fiber mat and the Al 2 O 3 ceramic cloth are sewed together with the Kanthal-wire thread
  • these materials may be selected and combined in various ways in consideration of the heat resisting properties and economy. For instance, it is possible to make various modifications such as using a TiO 2 ceramic cloth in place of the Al 2 O 3 ceramic cloth, using a platinum wire in place of the Kanthal wire and so on.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Gas Burners (AREA)

Claims (6)

  1. Brenner mit Oberflächenverbrennung, der mit einem Diaphragma (M) mit einer ersten Lage (1) aus keramischem Stoff mit feuerfesten Eigenschaften, die eine Gasverbrennungszone bildet, und mit einer zweiten Lage (3) zum Zuführen eines Gases zur ersten Lage und zum Halten der ersten Lage (1) versehen ist, dadurch gekennzeichnet, daß die zweite Lage (3) sich zusammensetzt aus einer rostfreien Stahlfasermatte, die aus einer großen Anzahl von rostfreien Stahlfasern hergestellt ist, die miteinander durch Sintern verbunden sind, und daß der Brenner weiterhin eine dritte Lage (2) aufweist, die zwischen erster und zweiter Lage angeordnet ist, wobei die dritte Lage (2) aus einer rostfreien Stahlfasermatte besteht und mit der zweiten Lage (3) durch Sintern verbunden ist und erste Lage (1) und dritte Lage (2) mit einen Faden (4) aus feuerfestem Material verwendenden Maschinenstichen zusammengenäht sind und die Maschinenstiche in einem Kreuzmuster über im wesentlichen die ganze Fläche des Diaphragmas (M) zum Zusammenhalten von erster und dritter Lage gebildet sind.
  2. Brenner mit Oberflächenverbrennung gemäß Anspruch 1, dadurch gekennzeichnet, daß die erste Lage aus einem keramischen Faservlies besteht, das aus AL2O3-Fasern hergestellt ist.
  3. Brenner mit Oberflächenverbrennung gemäß Anspruch 1 oder 2, dadurch gekennzeichnet, daß der feuerfeste Faden (4) aus einem hitzeresistenten Metalldraht besteht.
  4. Brenner mit Oberflächenverbrennung gemäß einem der Ansprüche 1 bis 2, dadurch gekennzeichnet, daß der feuerfeste Faden (4) aus Keramikfasermaterial besteht.
  5. Brenner mit Oberflächenverbrennung gemäß einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, daß die erste Lage (1) die gleiche Porosität aufweist wie die Materialien der zweiten und dritten Lage.
  6. Brenner mit Oberflächenverbrennung gemäß einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Lage (1) aus keramischem Stoff und die rostfreien Stahlfasermatten der zweiten und dritten Lage (2, 3) im wesentlichen die gleiche Porosität von 90% oder mehr aufweisen.
EP91903697A 1990-01-31 1991-01-31 Brenner mit oberflächenverbrennung Expired - Lifetime EP0465679B1 (de)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP18956/90 1990-01-31
JP2018956A JPH0676841B2 (ja) 1990-01-31 1990-01-31 表面燃焼バーナ
PCT/JP1991/000122 WO1991011657A1 (en) 1990-01-31 1991-01-31 Surface combustion burner

Publications (3)

Publication Number Publication Date
EP0465679A1 EP0465679A1 (de) 1992-01-15
EP0465679A4 EP0465679A4 (en) 1993-02-10
EP0465679B1 true EP0465679B1 (de) 1997-10-01

Family

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Family Applications (1)

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EP91903697A Expired - Lifetime EP0465679B1 (de) 1990-01-31 1991-01-31 Brenner mit oberflächenverbrennung

Country Status (4)

Country Link
EP (1) EP0465679B1 (de)
JP (1) JPH0676841B2 (de)
DE (1) DE69127781T2 (de)
WO (1) WO1991011657A1 (de)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5205731A (en) * 1992-02-18 1993-04-27 Battelle Memorial Institute Nested-fiber gas burner
AT411106B (de) * 2000-03-22 2003-09-25 Wienerberger Ziegelind Wagen zum transport von keramikrohlingen
EP3118520B1 (de) * 2005-08-05 2024-03-13 Cascade Designs, Inc. Hochleistungsstrahlungsbrenner mit wärmetauscheroption
US11635204B2 (en) 2017-03-27 2023-04-25 Jfe Steel Corporation Surface combustion burner, composite burner, and ignition device for sintering machine

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1368084A (en) * 1972-08-08 1974-09-25 Cooperheat Surface combustion burner
JPS5230612Y2 (de) * 1974-05-27 1977-07-13
JPS6060525U (ja) * 1983-10-04 1985-04-26 東京瓦斯株式会社 予混合燃焼ガスバ−ナ
JP2697157B2 (ja) * 1989-06-27 1998-01-14 日本鋼管株式会社 バーナ板
JP2751425B2 (ja) * 1989-06-27 1998-05-18 日本鋼管株式会社 バーナ板
JP2697155B2 (ja) * 1989-06-27 1998-01-14 日本鋼管株式会社 バーナ板
JP2751426B2 (ja) * 1989-06-27 1998-05-18 日本鋼管株式会社 バーナ板
JP2697156B2 (ja) * 1989-06-27 1998-01-14 日本鋼管株式会社 バーナ板

Also Published As

Publication number Publication date
JPH0676841B2 (ja) 1994-09-28
JPH03225105A (ja) 1991-10-04
EP0465679A4 (en) 1993-02-10
EP0465679A1 (de) 1992-01-15
WO1991011657A1 (en) 1991-08-08
DE69127781D1 (de) 1997-11-06
DE69127781T2 (de) 1998-04-23

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