EP0701092A1 - Vorrichtung zum Ausbreiten von einer Flamme mit COANDA-Effekt und Ofen mit dieser Vorrichtung - Google Patents

Vorrichtung zum Ausbreiten von einer Flamme mit COANDA-Effekt und Ofen mit dieser Vorrichtung Download PDF

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Publication number
EP0701092A1
EP0701092A1 EP95401906A EP95401906A EP0701092A1 EP 0701092 A1 EP0701092 A1 EP 0701092A1 EP 95401906 A EP95401906 A EP 95401906A EP 95401906 A EP95401906 A EP 95401906A EP 0701092 A1 EP0701092 A1 EP 0701092A1
Authority
EP
European Patent Office
Prior art keywords
jet
flame
oven
gas
main
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Withdrawn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
EP95401906A
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English (en)
French (fr)
Inventor
Christian Larquet
Alain Villermet
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.)
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
Original Assignee
Air Liquide SA
LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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 Air Liquide SA, LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude filed Critical Air Liquide SA
Publication of EP0701092A1 publication Critical patent/EP0701092A1/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Withdrawn legal-status Critical Current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
    • F23D14/32—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air
    • 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
    • F23D14/20—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone
    • F23D14/22—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S239/00—Fluid sprinkling, spraying, and diffusing
    • Y10S239/07—Coanda

Definitions

  • the invention relates to a device for spreading a flame by the Coanda effect.
  • Heating nozzles are known, for example, comprising a central tube which delivers a combustible gas and an annular tube, surrounding the central tube, which delivers an oxidizing gas. It is known to place a cone-shaped obstacle in the flow of the jet of combustible gas in order to widen it. The annular jet of oxidizing gas is entrained by the combustible gas, which forms an enlarged flame.
  • the present invention relates to a flame spreading device which achieves this result.
  • Another advantage of this device is that it gives very good stability to the spread flame.
  • the spread flame obtained follows the curved surface perfectly, which makes it possible to obtain a very flat flame and therefore an excellent distribution of the heat which it produces.
  • the section of the main nozzle and the section of the secondary nozzle can naturally take a wide variety of forms.
  • the main nozzle has a circular section
  • the secondary nozzle of annular section, surrounds the main nozzle
  • the main nozzle is rectangular, at least one secondary nozzle delivering a tangential secondary jet to one of the sides of the rectangle formed by the section of the main nozzle.
  • the main nozzle can also have other very diverse shapes, for example square, polygonal, polygonal with rounded angles, ellipsoidal or ovoid, etc.
  • combustible gases for example methane or propane or any hydrocarbon.
  • the oxidizing gas is preferably oxygen, but it can also be air.
  • the invention also relates to an oven comprising walls delimiting an enclosure and heating means.
  • Ovens are already known comprising a refractory wall heated by a flame.
  • the refractory wall then heats the interior atmosphere of the furnace and the charge contained in the furnace.
  • flame spreading devices are used.
  • the main jet is substantially perpendicular to a wall of the oven, and the curved surface deflects the jet substantially by 90 ° so that the flame flows tangentially to a wall of the oven.
  • This embodiment makes it possible to widen the flame which becomes completely flat and to heat the refractory wall of the furnace. This gives a very good heat diffusion.
  • This embodiment is advantageously applied to small ovens in which the flame must not reach the charge to be heated.
  • ovens are also known in which it is desired to obtain a fine flame. We can in this case wish that the flame remains parallel to the surface of the bath and has a thickness as constant as possible in order to ensure a regular and homogeneous heating of the bath.
  • the zone substantially perpendicular to the wall of the furnace is arranged horizontally.
  • the zone substantially perpendicular to the wall of the furnace is arranged vertically.
  • the Coanda effect is a known phenomenon in which a jet flow remains attached to a tangent surface on which it flows.
  • the jet remains attached to the tangent surface even if the latter gradually deviates from its initial direction by a certain angle.
  • Figure 3 illustrates the principle of a flame spreading device according to the invention.
  • the device comprises a main nozzle 4 capable of delivering a gas, for example a combustible gas.
  • a gas for example a combustible gas.
  • the end of the nozzle 4 is located in a hole formed in a thick wall.
  • the main jet whose flow is shown diagrammatically by the arrows 6, opens in parallel to a curved wall 10 formed by the thick wall.
  • the secondary nozzle 8 consists of the space between the main nozzle 4 and the curved surface 10.
  • the secondary jet 12 for example of oxidizing gas, flows tangentially to the walls 10 at the outlet of the secondary nozzle 8.
  • L 'space between the outside of the main nozzle 4 and the wall 10 has a substantially constant section and of small dimension, for example 0.3 mm.
  • the secondary jet 12 When the secondary jet 12 is alone, it flows tangentially to the wall 10 by the Coanda effect. This wall is curved and gradually widens until it forms an angle of 90 ° relative to the axis of the main and secondary nozzles.
  • the secondary jet also called parietal jet because it flows along the wall 10, produces a strong depression in the central zone where the main nozzle 4 opens.
  • the parietal jet When the two jets, namely the main jet and the secondary jet (or parietal jet) flow simultaneously, the parietal jet whose flow speed is significantly higher than that of the main jet, sucks the latter. The two jets mix and the resulting jet flows horizontally.
  • the depression created by the Coanda effect at the heart of the parietal jet in the area of curvature is such that the entire main jet is driven by the parietal jet to follow the wall 10.
  • the equilibrium of the spread jet is perfectly stable in a range of relative speed of the parietal jet compared to the main jet and it is not possible to upset this balance.
  • the flow of primary gas for example combustible, mixes rapidly with the flow of secondary gas, for example oxidizing gas, to form a combustible mixture which gives rise to the flame.
  • secondary gas for example oxidizing gas
  • FIG. 1 a sectional view of an oven of the prior art, designated by the general reference 20.
  • This oven has an outer wall 11 of steel and an inner wall 22 lined with bricks of refractory material.
  • a hearth 24 is disposed on the bottom 26 of the oven.
  • the oven 20 includes heating means 30 which deliver a flame 32. It is known to use flame enlargement devices in order to obtain a flame as large and flat as possible so as to distribute the heat of this flame and to heat the part 28 in a homogeneous manner. This result cannot be easily achieved with the flame spreading devices currently known.
  • FIG. 4 shows heating means which equip an oven according to the present invention.
  • These heating means are constituted by a tube 4, of circular section, which constitutes a main nozzle.
  • the tube 4 is surrounded by a tube 7 also of circular section.
  • This tube 7 is connected to an O-ring piece 9.
  • the end of the tube 4 opens substantially in the middle of the thickness of the piece 9.
  • the piece 9 is inserted into the roof of the oven at the position of the heating means 30 shown on Figure 1. It has the curved surface 10.
  • the external wall of the furnace is constituted by a steel sheet 11 internally lined with refractory bricks 22.
  • the main nozzle 4 delivers a jet of combustible gas.
  • Comburan gas is brought into the annular space 8 between the tube 4 and the tube 7.
  • An annular passage of small thickness is between the outer surface of the part 9 and the outer diameter of the tube 4.
  • the typical value of this space is between 0.2 mm and 1 mm, but can take other values. This makes it possible to give the secondary jet a much higher flow speed than that of the main jet 6.
  • a pipe 34 in which a refrigerating fluid such as water circulates ensures the cooling of the part 9.
  • the part to be heated 28 is not touched by the flames because the latter flow along the wall. This characteristic is advantageous in particular in the case of an oven of small dimensions.
  • An oven was produced, the walls of which were lined with refractory material and had circular main nozzles 20 mm in diameter.
  • the annular space between the outside of the main nozzle and the tangent wall of the part 9 was 0.3 mm.
  • the power developed by each flame was of the order of 4.2 W.
  • FIG. 5 shows an alternative embodiment of the heating means fitted to an oven according to the invention.
  • the main nozzle and the secondary nozzle have a circular section
  • the main nozzle is constituted by a box 35 of elongated rectangular section.
  • a plate 37 delimits with the wall of the box 35 which faces it a space which makes it possible to supply the secondary gas, whether it is combustible gas or oxidizing gas.
  • the part 9 instead of having a toroidal shape, is of elongated rectilinear shape. It delimits a slot which extends parallel to the length of the oven.
  • the operation of this device is identical. Its advantage lies in the fact that it makes it possible to obtain a flame of great width, for example a flame which occupies most of the length of the oven. This provides better heat distribution over the length of the oven than a series of spaced heating nozzles.
  • FIG. 7 a third alternative embodiment of this device.
  • the main nozzle 35 has a square section and the part 9 also has a square section which is rounded at its four corners.
  • This variant makes it possible to obtain four flames, namely one flame per side. It goes without saying that a large number of other forms could be imagined.
  • FIG. 2 shows a second type of oven of the prior art, designated by the reference 40. It has walls formed of refractory bricks 22. This oven contains a charge 42. Heating nozzles 44 are provided for each side of oven 40.
  • the flames 46 produced by the nozzles 44 be parallel to the level of the charge 42 in order to heat it regularly.
  • the flames 46 release hydroxyl radicals which oxidize the charge 42 when they are too close to it. A fine flame, the distance to the surface of the bath is constant, avoids this drawback.
  • FIG 8 shows a vertical sectional view of heating means fitted to an oven according to the present invention.
  • These heating means comprise a box 35 of elongated rectangular section identical to the boxes shown in Figures 5 and 6.
  • a sheet metal housing 50 connects an outer wall of the box 35 to the wall of the oven.
  • a supply duct 52 transports a secondary gas 12 to the secondary nozzle constituted by a narrow width slot provided between an outer wall of the box 35 and the curved surface of the part 9.
  • the main jet 6 and the secondary jet 12 mix and follow the wall of the room 9. Note also the presence of the pipes intended for the optional circulation of a cooling fluid such as water.
  • the part 9 ends with a horizontal surface 54 perpendicular to the vertical wall 22 of the oven. In this way, the flame 56 is detached from the part 9 and enters the furnace horizontally, that is to say parallel to the surface of the glass bath 42.
  • the flame 56 does not flare and remains fine, even at a relatively large distance from the wall 22 of the oven. This characteristic is particularly interesting because it is thus possible to arrange the flame so that it is relatively close to the surface of the charge without, however, touching it.
  • FIG. 9 a third embodiment of a heating device for an oven.
  • the heating means are identical to those which have been described with reference to FIG. 8, but the orientation of the part 9 is different.
  • the reference 22a designates the upper part of the oven and the reference 22b the lower part of this oven. It can therefore be seen that the planar surface of the part 9 is arranged in a vertical plane instead of a horizontal plane according to FIG. 8.
  • the outlet section of the box 35 constituting the main nozzle is also arranged in a vertical plane. As a result the thin flame 56 is also.
  • a device such as that which is shown in FIG. 9 can be used in an oven of the type shown in FIG. 2.
  • the height of the piece 9 should not be very large. Indeed, it is desirable that the flame 56 remains relatively close to the free surface of the glass bath 42. This is the reason why will have a series of heating devices identical to that shown in Figure 9 along the length of the oven to heat the load.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Furnace Details (AREA)
EP95401906A 1994-09-07 1995-08-17 Vorrichtung zum Ausbreiten von einer Flamme mit COANDA-Effekt und Ofen mit dieser Vorrichtung Withdrawn EP0701092A1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9410704A FR2724217B1 (fr) 1994-09-07 1994-09-07 Dispositif d'etalement d'une flamme par effet coanda et four comportant ce dispositif
FR9410704 1994-09-07

Publications (1)

Publication Number Publication Date
EP0701092A1 true EP0701092A1 (de) 1996-03-13

Family

ID=9466755

Family Applications (1)

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EP95401906A Withdrawn EP0701092A1 (de) 1994-09-07 1995-08-17 Vorrichtung zum Ausbreiten von einer Flamme mit COANDA-Effekt und Ofen mit dieser Vorrichtung

Country Status (4)

Country Link
US (1) US5658141A (de)
EP (1) EP0701092A1 (de)
JP (1) JPH08178230A (de)
FR (1) FR2724217B1 (de)

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10000464B4 (de) 2000-01-07 2004-02-05 Zeuna-Stärker GmbH & Co KG Fluidisches Schaltelement
DE10000463A1 (de) 2000-01-07 2001-07-26 Zeuna Staerker Kg Fluidisches Schaltelement als Stoffstrom-Stellglied
MXPA02010663A (es) * 2000-04-30 2003-06-25 Casale Chemicals Sa Quemador.
US7175423B1 (en) * 2000-10-26 2007-02-13 Bloom Engineering Company, Inc. Air staged low-NOx burner
CA2413553C (en) * 2002-12-04 2008-07-29 Tornado Combustion Technologies Inc. Flare stack operating on coanda principle
DE10359362B3 (de) † 2003-12-16 2005-02-24 Rheinkalk Gmbh Verfahren zum Brennen von Kalkstein
US7757966B2 (en) * 2005-12-09 2010-07-20 Utah State University High-speed jet control
ITMI20060155A1 (it) * 2006-01-31 2007-08-01 Techint Spa Bruciatore di volta a fiamma piatta a basse emissioni inquinanti
US7878798B2 (en) * 2006-06-14 2011-02-01 John Zink Company, Llc Coanda gas burner apparatus and methods
US9121609B2 (en) * 2008-10-14 2015-09-01 General Electric Company Method and apparatus for introducing diluent flow into a combustor
JP5774431B2 (ja) * 2011-09-28 2015-09-09 中外炉工業株式会社 壁面輻射式バーナーユニット
US9333769B1 (en) 2014-12-15 2016-05-10 Eastman Kodak Company Apparatus for reducing wrinkles in moving web
US9370945B1 (en) 2014-12-15 2016-06-21 Eastman Kodak Company Apparatus for reducing wrinkles in moving web
US9201369B1 (en) 2014-12-15 2015-12-01 Eastman Kodak Company Method for reducing wrinkles in moving web
US9266363B1 (en) 2014-12-15 2016-02-23 Eastman Kodak Company Apparatus for reducing wrinkles in moving web
US9145015B1 (en) 2014-12-15 2015-09-29 Eastman Kodak Company Method for reducing wrinkles in moving web
US9216595B1 (en) 2014-12-15 2015-12-22 Eastman Kodak Company Apparatus for reducing wrinkles in moving web
US11255537B2 (en) 2016-07-08 2022-02-22 Nova Chemicals (International) S.A. Metallic burner tiles
US11585529B2 (en) 2017-11-20 2023-02-21 John Zink Company, Llc Radiant wall burner

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4146357A (en) * 1975-07-30 1979-03-27 Hotwork International Limited Fuel fired burners
JPS6426006A (en) * 1987-11-06 1989-01-27 Matsushita Electric Industrial Co Ltd Controller for fluid flow direction
US5110285A (en) * 1990-12-17 1992-05-05 Union Carbide Industrial Gases Technology Corporation Fluidic burner
GB2253576A (en) * 1991-01-24 1992-09-16 S & C Thermofluids Ltd Catalytic Coanda combustion

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3133731A (en) * 1961-07-17 1964-05-19 Zink Co John Apparatus for heating gases
US3836315A (en) * 1971-10-14 1974-09-17 Pyronics Inc Burner apparatus for flame propagation control
GB1593391A (en) * 1977-01-28 1981-07-15 British Petroleum Co Flare
IT1085350B (it) * 1977-04-19 1985-05-28 Montedison Spa Metodo per la preparazione di esafluoruro di zolfo ad elevata purezza,ed apparecchiatura per realizzarlo
SU779737A1 (ru) * 1978-08-29 1980-11-15 Всесоюзный научно-исследовательский институт металлургической теплотехники Плоскопламенна горелка

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4146357A (en) * 1975-07-30 1979-03-27 Hotwork International Limited Fuel fired burners
JPS6426006A (en) * 1987-11-06 1989-01-27 Matsushita Electric Industrial Co Ltd Controller for fluid flow direction
US5110285A (en) * 1990-12-17 1992-05-05 Union Carbide Industrial Gases Technology Corporation Fluidic burner
GB2253576A (en) * 1991-01-24 1992-09-16 S & C Thermofluids Ltd Catalytic Coanda combustion

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 13, no. 204 (M - 825) 15 May 1989 (1989-05-15) *

Also Published As

Publication number Publication date
JPH08178230A (ja) 1996-07-12
FR2724217B1 (fr) 1996-10-25
FR2724217A1 (fr) 1996-03-08
US5658141A (en) 1997-08-19

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