EP0536706A2 - Procédé pour la fabrication d'un stabilisateur de flamme pour un brûleur radiant et stabilisateur de flamme produit selon ce procédé - Google Patents

Procédé pour la fabrication d'un stabilisateur de flamme pour un brûleur radiant et stabilisateur de flamme produit selon ce procédé Download PDF

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Publication number
EP0536706A2
EP0536706A2 EP92117066A EP92117066A EP0536706A2 EP 0536706 A2 EP0536706 A2 EP 0536706A2 EP 92117066 A EP92117066 A EP 92117066A EP 92117066 A EP92117066 A EP 92117066A EP 0536706 A2 EP0536706 A2 EP 0536706A2
Authority
EP
European Patent Office
Prior art keywords
flame holder
holder according
laser
shaped body
boreholes
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Withdrawn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
EP92117066A
Other languages
German (de)
English (en)
Other versions
EP0536706A3 (en
Inventor
Siegfried W. Schilling
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.)
Luedi Roger
Original Assignee
Luedi Roger
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 Luedi Roger filed Critical Luedi Roger
Publication of EP0536706A2 publication Critical patent/EP0536706A2/fr
Publication of EP0536706A3 publication Critical patent/EP0536706A3/de
Withdrawn legal-status Critical Current

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    • 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
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/12—Radiant burners
    • F23D14/14—Radiant burners using screens or perforated plates
    • F23D14/145—Radiant burners using screens or perforated plates combustion being stabilised at a screen or a perforated plate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D2203/00—Gaseous fuel burners
    • F23D2203/10—Flame diffusing means
    • F23D2203/102—Flame diffusing means using perforated plates
    • 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 invention relates to a method for producing a flame holder for a radiation burner and to a flame holder produced by this method according to the preamble of claim 3.
  • the mixture of fuel and oxidizing agent passes through passage channels of the flame holder.
  • the combustion takes place in the wall structure of the flame holder in a relatively thin wall layer on the downstream surface of the flame holder.
  • the material of the flame holder takes on a temperature of around 600 to 1200 ° C depending on the power density. Accordingly, a considerable amount of heat is emitted by radiation to the environment, ie in particular to the combustion chamber walls.
  • the NO x emission is therefore a factor of 2 to 4 lower than that of free flame burners. Further advantages of the radiation burner compared to burners with a free flame are that no large-volume combustion chambers are required and that pulsations, which are difficult to control, especially in oil burners, do not occur.
  • Radiation burners with a generic flame holder are e.g. known from DE-OS 19 55 163 and US-PS 4,519,770.
  • the flame holder consists of a body made of ceramic fibers.
  • the felt of these ceramic fibers has sufficient porosity so that passage channels for the fuel-air mixture remain free.
  • the flame holders made of ceramic fibers can only be used to a limited extent in the temperature range.
  • the mechanical strength of the body made of ceramic fibers is not sufficient, so that in addition a supporting structure, e.g. in the form of a perforated plate is required.
  • the body of the radiation burner from metal fibers.
  • the metal fibers have a high thermal conductivity
  • the metal fibers must be stacked on one another in planes parallel to the surface of the flame holder in order to allow heat to spread in the surface of the flame holder, but to keep undesired heat propagation from the hot outlet surface to the upstream side of the flame holder as low as possible.
  • these flame holders can only be used in a limited temperature range and their mechanical strength is not sufficient for use without an additional support structure.
  • a sufficient mechanical inherent strength is finally achieved with flame holders that have a body made of porous sintered metal.
  • the sintering of the flame holder body results in insufficient dimensional accuracy, so that mechanical finishing is necessary.
  • the temperature range for the use of sintered metal flame holders is also limited.
  • the invention has for its object to provide a flame holder for radiant burners, which is not only suitable for gaseous fuels, but also in the same way for liquid fuels, which can be easily adapted to the particular burner configuration and has exactly reproducible burning properties.
  • the body with the passage channels is constructed from a ceramic powder using the plasma spraying technique.
  • the plasma spraying process provides moldings with high dimensional accuracy, so that post-processing is not necessary.
  • the plasma spraying process also gives great freedom in the design of the shaped body, so that it can be optimally adapted to the particular application and structural design of the radiation burner.
  • the shaped body can in particular be designed as a plate which can be used as a burner end wall.
  • the shaped body is preferably designed as a tube, the cross-sectional shape and size being freely selectable.
  • the molded body produced in the plasma spraying process has a high mechanical strength, so that it can be cantilevered mounted as a flame holder and an additional support structure is not required.
  • the plasma-ceramic molded body has a structure that ensures high dimensional stability under thermal alternating loads. The dimensional stability is therefore even at high point heat loads and the associated star ken temperature gradient is not affected.
  • the passage channels for the fuel-air mixture can therefore be drilled using a laser beam. Drilling with a laser beam allows the production of straight laser drill holes in precisely definable and reproducible size, shape, number and arrangement.
  • the straight through laser drill holes ensure an even and complete penetration of the fuel-air mixture.
  • the flame holder is therefore also and in particular suitable for liquid fuels, since the passage channels formed by the laser boreholes do not have any lateral branches and ramifications which can fill with liquid fuel as blind spaces. With the flame holder according to the invention, it has been possible for the first time to build a functional radiation burner for liquid fuels.
  • the generation of the passage channels by means of a laser beam has the further advantage that the diameter and the cross-sectional shape of the laser boreholes can be determined reproducibly, so that the optimal fuel passage can be achieved in coordination with the fuel composition and the desired burner output.
  • the areal density of the laser boreholes can also be freely selected and reproducibly maintained in order to obtain the desired power density.
  • the plasma-ceramic structure of the molded body also enables a higher limit temperature and thus a higher power density due to the high dimensional stability and the high thermal load capacity.
  • the arrangement of the laser boreholes can be freely chosen both in terms of their position and in terms of the areal density of the hole distribution. This enables a different distribution of the power density over the surface of the flame holder.
  • the power density can be optimally adapted to the structural design of the flame holder and the installation conditions in the burner.
  • the high mechanical strength and the low thermal conductivity of the plasma-ceramic material enable the shaped body to have a small wall thickness, which in turn has an advantageous effect on the production costs.
  • the plasma-ceramic molded body can consist of the same ceramic material.
  • the plasma spraying process also gives the possibility of varying the material composition of the plasma-ceramic molded body over its thickness.
  • the composition of the ceramic powder supplied in the plasma spraying process can be changed continuously, so that there is a continuously changing graduated composition of the shaped body. It can also be switched from a ceramic powder to a ceramic powder of a different type during the plasma spraying process, so that a two-layer, sandwich-like molded body results.
  • Such a changing composition of the ceramic material of the shaped body allows, for example, the outlet-side outer layer of the shaped body which has the highest temperature to be made of a ceramic material with a high melting temperature, e.g. To produce aluminum oxide, while the upstream layers of the molded body, which are not exposed to such high thermal loads, made of a ceramic material with a lower melting point, such as e.g. Aluminum titanate.
  • the thin wall thickness of the plasma-ceramic molded body is generally sufficient to maintain a sufficient temperature gradient between the hot outlet side of the molded body and the inlet side with a lower temperature.
  • a thermal insulation layer made of a porous material is attached to the inlet side of the plasma-ceramic molded body, which prevents flame flashback through the laser boreholes into the inlet-side space.
  • This porous thermal barrier layer can be made of a conventional material, e.g. made of a ceramic fiber material.
  • the plasma-ceramic molded body with its high mechanical stability can also serve as a support structure for the porous thermal insulation layer.
  • the flame holder for a radiation burner for liquid or gaseous fuels consists of a shaped body 10, in which laser boreholes 12 are drilled by means of a laser beam as passage channels.
  • the molded body 10 is produced by the plasma spraying process.
  • a hydrogen-oxygen plasma is generated in a plasma torch, which reaches a temperature of 15,000 ° C. in its center and leaves the torch housing at high speed as a jet.
  • a ceramic powder is injected into the plasma jet emerging from the burner housing.
  • the hot plasma jet melts this ceramic powder on the surface and hurls it at high speed layer by layer onto a metallic spray core.
  • the powder particles deform on impact, form a solid bond with each other and cool down quickly.
  • the finished plasma-ceramic molded body can be easily separated from the metallic injection core.
  • the plasma-ceramic molded body has high mechanical strength and dimensional stability and can be used as a dimensionally accurate, ready-to-install part without any finishing work.
  • the metallic spray core is retained and can be used again and again.
  • the plasma-ceramic molded body can thus be inexpensively manufactured in large numbers with reproducible high dimensional accuracy and dimensional accuracy.
  • moldings 10 can be produced in multiple shapes.
  • a shaped body 10 is shown in the form of a flat plate, as it e.g. can be used as the end wall of a burner.
  • FIGS. 4 and 5 show a tubular shaped body 10 which can be used as the jacket of a burner.
  • the laser boreholes 12 are drilled in the molded body 10 by means of a laser beam.
  • the extremely high thermal shock resistance of the plasma-ceramic material enables the high point thermal stress during laser beam drilling without this leading to damage or deformation of the molded body 10.
  • the laser boreholes 12 are designed with a circular cross section. It is also possible to make the laser drill holes with a different cross-sectional shape, for example slit-shaped, elliptical or polygonal. In addition to the advantage of simple manufacture, the circular cross section also has the most favorable flow properties.
  • the laser boreholes 12 run perpendicular to the surface of the shaped body 10. This is advantageous if the fuel flows to the shaped body 10 in gaseous form or as an aerosol in a uniform flow distribution. In the exemplary embodiment of FIGS. 1 and 2, this is the case when the volume flow of the fuel-air mixture occurs in the same distribution, perpendicular to the entire surface of the plate-shaped molded body 10. In the exemplary embodiment in FIGS. 4 and 5, this is the case when this volume flow strikes the tubular shaped body 10 radially and uniformly over the entire circumference.
  • the laser boreholes 12 do not run perpendicular to the surface of the shaped body 10, but are inclined at an angle to the normal to the surface. As a result, even with such an asymmetrical flow of the gaseous or aerosol fuel, the laser boreholes 12 can be substantially aligned with the direction of flow of the fuel-air mixture.
  • the laser boreholes 12 are formed continuously with a constant cross section.
  • a change in the cross-section e.g. a conical configuration of the laser boreholes 12 is advantageous.
  • the plasma-ceramic molded body 10 consists homogeneously of the same ceramic material, preferably aluminum oxide.
  • the molded body 10 is constructed in two layers from an outer layer S1 and an inner layer S2.
  • the outer layer S1 consists, for example, of aluminum oxide with a high melting temperature of 2050 ° C.
  • the inner layer S2 consists of aluminum titanate with the lower melting temperature of 1860 ° C.
  • the ceramic powder of the inner layer for example aluminum titanate
  • the ceramic powder for the outer layer for example aluminum oxide
  • the flame holder has the following typical data for use in an oil jet burner.
  • the laser boreholes 12 have a diameter D of 0.1 to 0.7 mm.
  • the best burner properties are obtained with a diameter D of 0.2 to 0.3 mm.
  • the length L of the laser drill holes 12, which corresponds to the material thickness of the molded body 10, is in the range from 1.0 to 4.0 mm.
  • the best burner values are obtained with a length L of 1.5 to 2.5 mm.
  • the ratio of the length L to the diameter D of the laser boreholes 12 is present partly in the range from 8 to 12.
  • the laser boreholes 12 are generally arranged in a uniform distribution with the same mutual distance, unless a different flow through the shaped body 10 in different areas of the flame holder is advantageous to adapt to the burner geometry. In such cases, a lower density of the laser boreholes 10, i.e. a larger mutual distance may be provided. It is also possible to reduce the diameter of the laser boreholes 12 in certain areas of the molded body 10 in order to reduce the flow through them in these areas of the molded body 10.
  • FIG 1 an embodiment of the molded body 10 is shown, in which the laser drill holes 12 are arranged in a regular grid with the same mutual distance.
  • the division of this grid, ie the hole center distance of the laser drill holes 12, is denoted by T.
  • the free passage area of the laser boreholes 12 is denoted by F f
  • F t the total area of the shaped body 10 assigned to the respective laser borehole 12
  • the dependency shown in FIG. 3 results from the ratio of the pitch T to the diameter D of the laser boreholes 10.
  • the area ratio F f / F t is between approximately 0.25 and 0.07, ie the free passage area F f of the laser boreholes 12 is between 7 and 25% of the total area of the molded body 10.
  • the ratio of division to diameter T / D can also vary within this advantageous range, in particular in the case of a tubular shaped body 10, as shown in FIGS. 4 and 5, the ratio T / D can change over the axial length of the flame holder in order to to obtain a different power density in individual axial areas.
  • the value of 3.5 shown in FIG. 3 as the upper range limit of the ratio T / D is obtained, for example, in the case of laser drill holes 12 arranged in a uniform grid with a diameter of 0.3 mm and a hole density of 104 holes per cm 2 .

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Coating By Spraying Or Casting (AREA)
EP19920117066 1991-10-08 1992-10-06 Method of manufacturing a flame holder for a radiant burner and flame holder made by means of this method Withdrawn EP0536706A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4133251A DE4133251C2 (de) 1991-10-08 1991-10-08 Verfahren zum Herstellen eines Flammenhalters für einen Strahlungsbrenner und nach diesem Verfahren hergestellter Flammenhalter
DE4133251 1991-10-08

Publications (2)

Publication Number Publication Date
EP0536706A2 true EP0536706A2 (fr) 1993-04-14
EP0536706A3 EP0536706A3 (en) 1993-08-25

Family

ID=6442227

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19920117066 Withdrawn EP0536706A3 (en) 1991-10-08 1992-10-06 Method of manufacturing a flame holder for a radiant burner and flame holder made by means of this method

Country Status (2)

Country Link
EP (1) EP0536706A3 (fr)
DE (1) DE4133251C2 (fr)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995023315A1 (fr) * 1994-02-23 1995-08-31 Stichting Energieonderzoek Centrum Nederland Procede et appareil de brûlage d'un combustible gazeux tres reactif
DE19627103C1 (de) * 1996-07-05 1997-07-24 Schwank Gmbh Brennerelement
WO2000042356A1 (fr) * 1999-01-14 2000-07-20 Krieger Gmbh & Co. Kg Bruleur a emission d'infrarouges sous forme d'emetteur plan
WO2008125796A1 (fr) * 2007-04-12 2008-10-23 Mont Selas Limited Dispositif de brûleur
WO2009062815A2 (fr) * 2007-11-16 2009-05-22 BSH Bosch und Siemens Hausgeräte GmbH Composants structurels traités pour un appareil de cuisson
IT202100011888A1 (it) * 2021-05-10 2022-11-10 Beckett Thermal Solutions S R L Membrana di combustione per un bruciatore a gas
EP4092322A1 (fr) * 2021-05-20 2022-11-23 Beckett Thermal Solutions Ltd. Membrane de brûleur à gaz

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT504398B1 (de) * 2006-10-24 2008-07-15 Windhager Zentralheizung Techn Porenbrenner, sowie verfahren zum betrieb eines porenbrenners
CN109851390B (zh) * 2019-01-28 2021-06-11 西北工业大学 一种内含导热导电cnt网络的陶瓷基复合材料的制备方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3067811A (en) * 1956-07-02 1962-12-11 Otto Bernz Co Inc Gas burner
US4063873A (en) * 1975-10-20 1977-12-20 Rinnai Kabushiki Kaisha Infrared gas burner plate
GB2135766A (en) * 1983-02-16 1984-09-05 Matsushita Electric Ind Co Ltd Burner skeleton
EP0187508A2 (fr) * 1984-12-20 1986-07-16 Ngk Insulators, Ltd. Brûleur pour combustion superficielle à haute température
US4640261A (en) * 1984-01-30 1987-02-03 Rinnai Kabushiki Kaisha Ceramic burner plate for gas combustion
US4948941A (en) * 1989-02-27 1990-08-14 Motorola, Inc. Method of laser drilling a substrate
DE4041061A1 (de) * 1989-12-22 1991-06-27 Siemens Ag Brennerplatte fuer einen flaechenbrenner

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4650619A (en) * 1983-12-29 1987-03-17 Toshiba Ceramics Co., Ltd. Method of machining a ceramic member

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3067811A (en) * 1956-07-02 1962-12-11 Otto Bernz Co Inc Gas burner
US4063873A (en) * 1975-10-20 1977-12-20 Rinnai Kabushiki Kaisha Infrared gas burner plate
GB2135766A (en) * 1983-02-16 1984-09-05 Matsushita Electric Ind Co Ltd Burner skeleton
US4640261A (en) * 1984-01-30 1987-02-03 Rinnai Kabushiki Kaisha Ceramic burner plate for gas combustion
EP0187508A2 (fr) * 1984-12-20 1986-07-16 Ngk Insulators, Ltd. Brûleur pour combustion superficielle à haute température
US4948941A (en) * 1989-02-27 1990-08-14 Motorola, Inc. Method of laser drilling a substrate
DE4041061A1 (de) * 1989-12-22 1991-06-27 Siemens Ag Brennerplatte fuer einen flaechenbrenner

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1995023315A1 (fr) * 1994-02-23 1995-08-31 Stichting Energieonderzoek Centrum Nederland Procede et appareil de brûlage d'un combustible gazeux tres reactif
NL9400280A (nl) * 1994-02-23 1995-10-02 Stichting Energie Werkwijze voor de verbranding van hoogreaktieve gasvormige lucht/brandstof-mengsels en branderinrichting voor het uitvoeren van deze werkwijze.
DE19627103C1 (de) * 1996-07-05 1997-07-24 Schwank Gmbh Brennerelement
EP0816757A2 (fr) 1996-07-05 1998-01-07 Schwank GmbH Elément de brûleur
WO2000042356A1 (fr) * 1999-01-14 2000-07-20 Krieger Gmbh & Co. Kg Bruleur a emission d'infrarouges sous forme d'emetteur plan
US6575736B1 (en) 1999-01-14 2003-06-10 Kreiger Gmbh & Co. Kg Infrared radiator that is designed as surface radiator
WO2008125796A1 (fr) * 2007-04-12 2008-10-23 Mont Selas Limited Dispositif de brûleur
WO2009062815A2 (fr) * 2007-11-16 2009-05-22 BSH Bosch und Siemens Hausgeräte GmbH Composants structurels traités pour un appareil de cuisson
WO2009062815A3 (fr) * 2007-11-16 2010-03-11 BSH Bosch und Siemens Hausgeräte GmbH Composants structurels traités pour un appareil de cuisson
IT202100011888A1 (it) * 2021-05-10 2022-11-10 Beckett Thermal Solutions S R L Membrana di combustione per un bruciatore a gas
EP4089328A1 (fr) * 2021-05-10 2022-11-16 Beckett Thermal Solutions S.R.L. Membrane de combustion pour un brûleur à gaz
EP4092322A1 (fr) * 2021-05-20 2022-11-23 Beckett Thermal Solutions Ltd. Membrane de brûleur à gaz
GB2606769A (en) * 2021-05-20 2022-11-23 Beckett Thermal Solutions Ltd Gas burner membrane

Also Published As

Publication number Publication date
DE4133251C2 (de) 1995-12-14
EP0536706A3 (en) 1993-08-25
DE4133251A1 (de) 1993-04-15

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