EP0679239A1 - Method for producing a gas burner element, burner element and burner using same. - Google Patents

Method for producing a gas burner element, burner element and burner using same.

Info

Publication number
EP0679239A1
EP0679239A1 EP94904676A EP94904676A EP0679239A1 EP 0679239 A1 EP0679239 A1 EP 0679239A1 EP 94904676 A EP94904676 A EP 94904676A EP 94904676 A EP94904676 A EP 94904676A EP 0679239 A1 EP0679239 A1 EP 0679239A1
Authority
EP
European Patent Office
Prior art keywords
strip
strips
grooves
burner
sections
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.)
Granted
Application number
EP94904676A
Other languages
German (de)
French (fr)
Other versions
EP0679239B1 (en
Inventor
Mer Joseph Le
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of EP0679239A1 publication Critical patent/EP0679239A1/en
Application granted granted Critical
Publication of EP0679239B1 publication Critical patent/EP0679239B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/48—Nozzles
    • F23D14/58—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration
    • F23D14/583—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration of elongated shape, e.g. slits
    • F23D14/586—Nozzles characterised by the shape or arrangement of the outlet or outlets from the nozzle, e.g. of annular configuration of elongated shape, e.g. slits formed by a set of sheets, strips, ribbons or the like
    • 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
    • F23D2211/00—Thermal dilatation prevention or compensation

Definitions

  • the present invention relates to a method of manufacturing a gas burner element. It also relates to a burner element and a burner in use.
  • Fibers which may be made of ceramic or metallic materials, or else of rigid, perforated, metallic or ceramic plates, allowing combustion distributed over a large area with a homogeneous and therefore lower flame temperature. than that obtained by other burner techniques.
  • combustion - which is a chemical reaction of oxidation of a reducing reagent (gas) by an oxidizing reagent (air) - are complex and varied.
  • the "combustion site" is in fact at the same time the seat of reaction, formation and reduction of the oxides which have just been born.
  • document FR-A-1 037 897 discloses several embodiments of a gas burner.
  • the burner is formed from several parallel and contiguous metal strips which carry channels on only one of their large faces. The air + gas mixture flows through these channels.
  • the flame obtained with this type of burner is not uniform and tends to "drop" from the surface of the burner. In other words, it is not stable.
  • the present invention aims in particular to propose a method of manufacturing a gas burner element making it possible to obtain a very good quality of combustion of the gas-air mixture, that is to say rejecting the least possible polluting gases, while being of an economic implementation.
  • This process comprises, in a manner known by FR-A-1 037 897, the steps according to which: a) at least one metal strip whose width corresponds to the thickness of the burner element to be obtained is subjected to an operation aimed at forming in one of its large faces a series of grooves opening onto its banks, the other large face of the strip being kept smooth; b) several sections of this metal strip, or several metal strips, are juxtaposed in order to apply them one against the other in such a way that their flat face is in contact with the grooved face of the section or of the adjacent strip, and vice versa; c) assembling all of the sections of strips or strips thus juxtaposed (s) to obtain a rigid element.
  • openings have an elongated rectangular shape and are arranged in the longitudinal direction of the strip;
  • the mat ⁇ asting operation is carried out using rotary forming tools, such as a ribbed wheel and a counter-roller.
  • rotary forming tools such as a ribbed wheel and a counter-roller.
  • the grooves are made transversely on the strip;
  • step b sections or bands are used whose grooves are directed differently and / or whose sections are different;
  • step a an alumina or pure chromium powder is sprayed onto the strip, this projection taking place hot or cold, and in that, following step c), it is subjected said element being heated so as to cause said powder to melt.
  • the invention also relates to a gas burner element.
  • This burner element of the type formed by a juxtaposition of sections of strips or strips applied against each other, each section or strip having on one of its large faces a series of grooves opening onto its banks, the other large face being smooth, the juxtaposition being such that their flat face is in contact with the grooved face of the section or of the adjacent strip, is characterized by the fact that the edges of the strips or sections have bosses located in the extension of said grooves.
  • the juxtaposition consists of a winding of one or more metal strips on it (s) -same (s), the winding axis being perpendicular to the large faces of said (said) strip (s).
  • the element has several weld lines on its external or internal surface, these lines being equidistant - or substantially equidistant - angularly from one another and arranged along the generatrices of the winding.
  • the invention also relates to a gas burner which includes such an element.
  • said element is mounted between two flanges, each being equipped with a flexible refractory seal for the reception of the ends of the element, so that the latter can diate freely, while being held between the flanges.
  • the flexible joint is formed of ceramic fibers.
  • the total thickness of the strip which constitutes the burner may have a different structure depending on whether a blue flame or a radiant combustion is desired.
  • the grooves which cross the strip are, in a cases, laminar. In the other, they pass through a "labyrinth structure" which causes a considerable drop in thermal conductivity between the face exposed to combustion and the opposite face, exposed to cold gases.
  • FIG. 1 is a schematic view illustrating the implementation of the first step of the method of the invention
  • FIG. 2A and 2B are respectively top and side views of a strip after the implementation of the first step of the method;
  • FIG. 3 is a schematic view illustrating an optional punching step, which can be implemented prior to the first step illustrated in Figure 1;
  • FIG. 6 is a schematic top view of a strip obtained according to the method illustrated in Figure 5;
  • FIG. 7 is a schematic side view of a stack of metal strips according to that shown in Figures 2A and 2B;
  • FIG. 8 is a view of the stack of Figure 6, cut transversely by the broken plane VIII-VIII of Figure 7;
  • Figure 9 is a view similar to Figure 8, but showing a stack of strips of the same type, subjected prior ⁇ ment punching;
  • FIG. 10 is a schematic top view of a burner comprising an element according to the present invention.
  • FIG. 1 1 is a schematic view of the means for implementing a second method of manufacturing the burner element
  • FIG. 12 schematically shows the implementation of a third method of manufacturing a burner element
  • FIG. 13 is a partial perspective view of an element obtained in accordance with the manufacturing method of Figure 1 2;
  • - Figure 14 is a perspective view of the element of Figure 1 3, on which were made weld lines;
  • FIG. 1 5 partially shows, in vertical section of a burner comprising an element according to Figure 1;
  • - Figure 1 6 is a top view, in cross section of the burner of Figure 15, along the section plane XVI-XVI;
  • FIG. 17 is an enlarged view of part of Figure 15;
  • Figure 18 is a partial view similar to that of Figure 16, but on a larger scale;
  • FIG. 19 is a detailed view of the means used for stacking several elements on top of each other;
  • FIG. 20 is a perspective view of another embodiment of the burner;
  • FIG. 21 is a detailed view of part of the burner in FIG. 20.
  • This step is implemented by means of a rotary wheel 2, a counter-roller 2 'and guide rollers G and G'.
  • the strip 1 has a width of 6 mm and a thickness of 0.5 mm. This width corresponds to the thickness of the burner element that one wishes to obtain.
  • rollers G and G ' are rotary and guide the metal strip 1 in the direction i in the direction of the wheel 2 and of the counter-roller 2'.
  • Appropriate means ensure the continuous and rotary drive of the latter. They have not been represented in order not to unnecessarily overload the figure.
  • the wheel 2 whose direction of rotation has been symbolized by the arrow g, is a cylindrical metal roller which has reliefs (teeth) 20 and 21 at its periphery.
  • these reliefs have been dimensionally exaggerated to allow a better understanding of the way in which the process step is implemented.
  • the wheel has two alternating series of reliefs of different height which extend transversely over its entire periphery.
  • the reliefs consist of parallel ribs, with a rounded free edge (semi-cylindrical).
  • the strip 1 is guided in the direction of the arrow _f_ between the rollers G and G 'then forced between the wheel and the counter roller 2', the latter being rotated in the direction of the arrow h_ .
  • a cold stamping of the strip is thus carried out, during which the material located in line with the reliefs is compressed and crushed in its thickness, so that the excess material is forced to creep laterally, towards the edges of the strip.
  • the strip 1 has on its large upper face 1 1 a series of channels or transverse grooves 4 and 4 'whose shape is substantially complementary to that of the ribs 20 and 21. Its lower face is flat.
  • FIGS. 2A and 2B show in detail the appearance of a portion of treated metal strip.
  • the bottom of the grooves 4 and 4 ′ has a section in the shape of an arc of a circle.
  • the diameter of the corresponding circles is respectively 0.25 and 0.15 mm.
  • Other cross-sectional shapes can be provided, in particular rectangular.
  • FIG 3 there is shown a strip portion 1 which has a series of grooves or transverse channels 50 all of the same section.
  • the bosses formed at the two ends of the channels are also identical.
  • the strip 1 shown in FIG. 4 comprises, for its part, a series of grooves 5 ′ arranged obliquely, that is to say slightly inclined relative to the transverse direction with, at each of their ends, a boss 50 '. It is of course possible to choose the orientation of the grooves that one wishes to obtain.
  • the strip is subjected, before stamping, to a punching operation, using a tool 3 and a matrix 3 '.
  • tools are intended to form a series of perforations in the strip.
  • tool 3 has three punches
  • the strip is then subjected to the stamping operation described with reference to FIG. 1.
  • these perforations 12 and 1 3 are slots distributed along two lines parallel to the long sides of the strip and have the shape of elongated rectangles separated by a small amount of material.
  • a strip can comprise for example four lines of perforations. The interest of these will be explained later.
  • the second step of the method of the invention consists in juxtaposing and assembling several portions of strip so that these portions are in contact by their large faces.
  • the grooved face 1 1 of a section being in contact with the face 10 of the adjacent section, it creates between the two strips a series of passages of different sections, opening on each bank.
  • the sections 1 00 are assembled to obtain a rigid element. This operation can be performed for example by securing the ends of the sections to a fixing plate.
  • FIG 10 schematically shows a top view of a gas burner which is equipped with an element according to the present invention.
  • This burner 6 includes a base 60 of substantially parallelail-piped shape, the upper face of which is partially open. This opening (not visible) has dimensions adapted to receive, without significant play, a plate 1 03 formed of an assembly of portions of metal strips held together by end plates 61.
  • a conduit 62 On one of the side faces of the base 60 is connected a conduit 62 for supplying air / gas mixture. This mixture is brought to the underside of the plate 103 and can flow freely through the latter through the grooves which it comprises.
  • the second step of it consists in juxtaposing several grooved metal strips by winding them on themselves so as to obtain a disc-shaped plate.
  • the strip portions having undergone the grooving and, optionally, punching operation are guided between rollers 20, 20 ', 70, 70' and 80, 80 '.
  • the strips are then directed around a rotary mandrel 97 whose direction of rotation is identified by the arrow k.
  • the winding is obtained in such a way that the winding axis 970 of the mandrel is parallel to the large faces of the strips.
  • the winding obtained has the shape of a disc.
  • the grooves formed in the strips are parallel to the axis of the disc.
  • the strips 1, 1 ′, 1 ′′ may respectively have grooves such as those shown in FIGS. 2, 3 and 4.
  • the strip 1 is bent and then wound around a rotary mandrel 98 of axis 99, so that the large faces of this strip are perpendicular to the axis 99.
  • annular element 106 FIG. 13
  • the grooves formed in the bands extend radially (that is to say perpendicular to the axis of the winding), or are slightly inclined relative to the radial direction if we are dealing with a stamping. "oblique" of the kind shown in Figure 4.
  • the passages formed by these ribs connect to each other the inner and outer cylindrical wall surfaces of the winding.
  • Such a burner element can be used for example in combination with a cylindrical heat exchanger, the burner being placed in its center.
  • the manufacture of the element is finally completed by a mutual fixing of the turns of the winding, by welding.
  • the element 106 shown in FIG. 14 has received several weld lines or beads 107 at its exterior or interior wall surface (not shown). These weld lines extend along generatrices of the cylindrical annular element 106 and are angularly equidistant from each other.
  • the weld lines can be made using a stainless steel wire using a thumbwheel, using the so-called “Tig” technique (In English: Tungsten inert gaz) or "Mig", or at laser.
  • the number of weld lines must be reasonable in relation to the diameter of the element. Thus, for example, eight weld lines are produced for an element having an outside diameter of 126 mm.
  • the penetration of the weld material into the element should preferably remain low so as not to cause significant mechanical stresses. Thus, this penetration advantageously does not exceed one third of the width of the bands which constitute the element.
  • Figures 1 5 to 18 is shown a gas burner equipped with an element 106 according to the description which has just been made.
  • the element 106 of axis XX ', is interposed between two flanges 61', 60 '.
  • the lower flange 61 ' is a thin disc; it has an edge 61 1 'raised at a right angle upward which externally delimits an annular groove 610'.
  • a flexible annular seal 65' for example made of ceramic fibers having an "L" section whose wings are applied respectively against the edge 61 1 'and against the bottom of the groove 610' .
  • the tie rods are fixed to the disc by any suitable means, for example by means of screws (not shown).
  • the upper flange 60 ' has the shape of a thick crown. Its underside has an annular groove 600 'which receives a flexible seal 66' similar to the seal 65 'but of "U" section. It also includes a series of bores, not shown, for fitting, without significant play, the upper end of the tie rods 64 ′. This interlocking is completed by a fixing (for example by means of screws).
  • the arrangement of the groove 600 ′ is such that when the flange 60 ′ is in place on the tie rods 64 ′, the seals 65 ′ and 66 ′ are plumb with each other. Between the flanges 60 'and 61' is mounted the element 106, the upper and lower end faces of which are in contact with the seals 65 'and 66', without there being excessive tightening of the element. between the joints.
  • the number of tie rods 64 ′ is equal to the number of weld lines of the element 106 and the tie rods are made to correspond with the lines of the welds so that they are opposite one another.
  • the burner also comprises two perforated cylindrical grids 62 'and 63' whose respective diameters are such that they are distributed on either side of the tie rods 64 '.
  • the grid 63 'of smaller diameter is located inside the series of tie rods 64'.
  • the grid 62 ′, of larger diameter, is external to the latter and has a series of projections 620 ′ constituted by “V” folds extending along generators and directed towards the outside, which bear against the internal wall of the element 106 and make it possible to maintain a constant spacing between the latter and the grid. On the inside, the projections keep the grid centered on the tie rods.
  • Figure 19 is shown an annular profile, of section in the shape of "H", which allows to stack two elements 106 coaxially one on the other; the upper and lower grooves of this profile each receive a flexible seal 68 ′, respectively 69 ′, of "L” section, for example made of ceramic fibers.
  • the burner 6 "of FIG. 20 is equipped with an element 108 formed by a juxtaposition of portions of slightly curved metal bands.
  • Each band is formed by a sector of annular cylindrical burner element conforming to that of FIG. 14 , of large diameter
  • the air / gas mixture A + G arrives at the level of the lower face of the plate formed by the assembly of the metal strips and flows from bottom to top through the channels 4 and 4 'of this plate. Because these channels have a small section and a long length, the body of the plate is relatively cold compared to the flame.
  • the thickness of the assembly exposed to the flame, located above the perforations 12 and 13 does not allow a flashback to the labyrinths formed by the layers of perforations, thus avoiding interstitial combustion in these labyrinths, this which would lead to hot spots conducive to increasing pollution, especially Nox and CO.
  • the labyrinth zone constitutes in the thickness of the burner a transition zone with low thermal conductivity, between the hot and radiant zone and the cold zone.
  • the space between the perforations and the width of the latter define the dimensions of the points which alone transmit heat from one face 105 to the other 104.
  • the width of the slots constitutes the number of these points.
  • the temperature at face 104 is too high to resist adequately during tens of thousands of hours of operation, even when using refractory steels. This is why the strips can be subjected, after their stamping, to a hot spraying of alumina or pure chromium powder, a few microns thick, with an appropriate device. This spraying can also take place when cold, the powder then being mixed with a binder. After juxtaposition of the strips, the assembly is passed through the oven in a neutral atmosphere or under vacuum. This causes the powder to melt and diffuse into the metal that makes up the strips. The burner thus obtained is perfectly rigid, due to the contact points established by the molten powder, and can suitably withstand high temperatures.
  • An air / gas mixture A + G is brought in from above the burner as shown in FIG. 15 and occupies the interior space delimited by the grid 63 '.
  • the percentage of openings in this grid is chosen such that there is an overall expansion of the volume of air / gas mixture. In other words, a substantially uniform pressure is created over the entire height of the burner.
  • the second grid 62 ′ ensures a good distribution of the flow of mixture A + G towards the burner element 106.
  • the intermediate space between the two grids makes it possible to generate a second expansion.
  • the element 106 tends to expand, both in length and according to its diameter. The phenomenon is not thwarted, because the element is interposed between two flexible seals. The burner element can therefore deform freely, the cohesion of the assembly being in any case ensured by the weld lines, the expansion of which follows that of the metal strips.
  • the air / gas mixture radially crosses the passages between the turns of the winding 106, and the combustion takes place on the external surface of the burner element, the bosses lining said surface promoting the attachment of the flames, as has been explained. above with reference to the embodiment of FIG. 8.
  • the operation of the burner in FIG. 20 is substantially the same as that described above.
  • the grid 1 12 is used for the correct distribution of the mixture A + G.
  • the latter which is curved like the burner element 108 itself, tends to deform (by thermal expansion) like the latter, further accentuating its curved.
  • the channels conducive to the flow of the material are produced. mixture of air / gas but also the reliefs which allow the flame to hang on the upper surface of the burner.
  • the element of the present invention makes it possible to obtain excellent combustions even at extreme air and gas flow rates.
  • the CO emission is of the order of 6 to 10 ppm, so that the combustion hygiene is remarkable.
  • the emission of Nox (nitrogen oxides) is 2 to 8 ppm, this in a range of power variation from 5 to 30 kW for a burner element of 126 mm in diameter and 120 mm in length.

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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)

Abstract

A method for producing a gas burner element, wherein (a) at least one metal strip (1) with a width matching the thickness of the desired burner element is cold formed to provide a series of grooves (4, 4') across the full width of one of the large sides (11) of the strip while the other large side (10) is left smooth, the resulting metal flow causing bumps to form on the strip edges at the ends of the grooves (4, 4'); (b) a number of sections of said metal strip (1), or a number of metal strips, are placed side by side such that their plane surfaces (10) contact the grooved surface (11) of the adjacent section or strip, and vice versa; and (c) the strip sections or strips (1) arranged side by side are assembled to form a rigid element. A burner element and a burner using said element and having an improved performance due to the large number of air/gas mixture passages formed by the grooves, and the 'flame stabilising' effect of the edge bumps, are also disclosed.

Description

PROCEDE DE FABRICATION D'UN ELEMENT DE METHOD FOR MANUFACTURING AN ELEMENT OF
BRULEUR A GAZ, ELEMENT DE BRULEURGAS BURNER, BURNER ELEMENT
ET BRULEUR EN FAISANT UTILISATIONAND BURNER USING
La présente invention concerne un procédé de fabrication d'un élément de brûleur à gaz. Elle concerne également un élément de brûleur et un brûleur en faisant utilisation.The present invention relates to a method of manufacturing a gas burner element. It also relates to a burner element and a burner in use.
L'évolution des coûts de l'énergie et les problèmes de •5 pollution de notre atmosphère conduisent les concepteurs à mettre au point de nouvelles générations d'appareils de chauffage qui assurent un haut rendement de combustion et une parfaite maîtrise de la qualité de combustion, réduisant ainsi simultanément la consommation d'énergie et l'émission de gaz polluants tels les oxydes d'azote (Nox) et le monoxyde de 0 carbone (CO).The evolution of energy costs and the problems of pollution of our atmosphere lead the designers to develop new generations of heaters which ensure a high combustion efficiency and a perfect control of the combustion quality. and simultaneously reducing the energy consumption and the emission of gaseous pollutants such as nitrogen oxides (NOx) and carbon monoxide of 0 (CO).
Ainsi, différents concepts de brûleurs dits "à combustion de surface" ont été développés.Thus, different concepts of so-called "surface combustion" burners have been developed.
Ceux-ci sont en général constitués de fibres qui peuvent être en matériaux céramiques ou métalliques, ou encore de plaquettes rigides, -5 perforées, métalliques ou céramiques, autorisant une combustion répartie sur une grande surface avec une température de flamme homogène et donc plus basse que celle obtenue par d'autres techniques de brûleurs.These generally consist of fibers which may be made of ceramic or metallic materials, or else of rigid, perforated, metallic or ceramic plates, allowing combustion distributed over a large area with a homogeneous and therefore lower flame temperature. than that obtained by other burner techniques.
Malheureusement, ils sont d'un prix de revient excessivement élevé. 0 Les mécanismes qui régissent la combustion - qui est une réaction chimique d'oxydation d'un réactif réducteur (gaz) par un réactif oxydant (air) - sont complexes et variés. Le "site de combustion" est en effet à la fois le siège de réaction, de formation et de réduction des oxydes qui viennent de naître. 5 On connaît par ailleurs, par le document FR-A-1 037 897 plusieurs modes de réalisation de brûleur à gaz. Ainsi, dans l'exemple de réalisation de la figure 10, le brûleur est formé de plusieurs bandes métalliques parallèles et contiguës qui portent des canaux sur une seule de leurs grandes faces. 0 e mélange air + gaz s'écoule au travers de ces canaux. Toutefois, la flamme obtenue avec ce type de brûleur n'est pas uniforme et a tendance à se "décrocher" de la surface du brûleur. En d'autres termes, elle n'est pas stable.Unfortunately, they are excessively high cost. 0 The mechanisms that govern combustion - which is a chemical reaction of oxidation of a reducing reagent (gas) by an oxidizing reagent (air) - are complex and varied. The "combustion site" is in fact at the same time the seat of reaction, formation and reduction of the oxides which have just been born. 5 Furthermore, document FR-A-1 037 897 discloses several embodiments of a gas burner. Thus, in the embodiment of FIG. 10, the burner is formed from several parallel and contiguous metal strips which carry channels on only one of their large faces. The air + gas mixture flows through these channels. However, the flame obtained with this type of burner is not uniform and tends to "drop" from the surface of the burner. In other words, it is not stable.
De plus, les gaz sont mal brûlés, ce qui se traduit par d'importants rejets polluants.In addition, the gases are badly burned, which results in significant polluting releases.
La présente invention vise notamment à proposer un procédé de fabrication d'un élément de brûleur à gaz permettant d'obtenir une très bonne qualité de combustion du mélange gaz-air, c'est-à-dire rejetant le moins possible de gaz polluants, tout en étant d'une mise en oeuvre économique.The present invention aims in particular to propose a method of manufacturing a gas burner element making it possible to obtain a very good quality of combustion of the gas-air mixture, that is to say rejecting the least possible polluting gases, while being of an economic implementation.
Il s'agit d'un procédé de fabrication simple à réaliser. Il permet d'obtenir un élément de brûleur qui sert de support ou de site de combustion et fournit une flamme silencieuse, émettant un taux faible de gaz polluants soit en flamme bleue, soit en combustion radiante, ceci sans décollement ni rentrée de la flamme, même à des débits extrêmes de mélange air/gaz.It is a simple manufacturing process. It makes it possible to obtain a burner element which serves as support or combustion site and provides a silent flame, emitting a low rate of polluting gases either in blue flame or in radiant combustion, this without detachment or reentry of the flame, even at extreme air / gas mixture flow rates.
Ce procédé comprend, de manière connue par FR-A-1 037 897, les étapes selon lesquelles : a) on soumet au moins une bande métallique dont la largeur correspond à l'épaisseur de l'élément de brûleur à obtenir à une opération visant à former dans l'une de ses grandes faces une série de rainures débouchant sur ses rives, l'autre grande face de la bande étant maintenue lisse ; b) on juxtapose plusieurs tronçons de cette bande métallique, ou plusieurs bandes métalliques, pour les appliquer les uns (les unes) contre les autres de telle manière que leur face plane soit en contact avec la face rainurée du tronçon ou de la bande adjacente, et inversement ; c) on assemble l'ensemble des tronçons de bandes ou des bandes ainsi juxtaposé(e)s pour obtenir un élément rigide. II est remarquable par le fait que ladite opération est une opération de matπçage au cours de laquelle on contraint le métal à fluer vers les chants de la bande de façon à y créer des bossages, dans le prolongement desdites rainures. Comme on le verra plus loin dans la description, ce procédé permet, dans une même étape et avec les mêmes moyens, de former dans la bande métallique les canaux pour l'écoulement du mélange gaz/air et les moyens d'accrochage de la flamme. Selon d'autres caractéristiques avantageuses mais non limitatives de ce procédé :This process comprises, in a manner known by FR-A-1 037 897, the steps according to which: a) at least one metal strip whose width corresponds to the thickness of the burner element to be obtained is subjected to an operation aimed at forming in one of its large faces a series of grooves opening onto its banks, the other large face of the strip being kept smooth; b) several sections of this metal strip, or several metal strips, are juxtaposed in order to apply them one against the other in such a way that their flat face is in contact with the grooved face of the section or of the adjacent strip, and vice versa; c) assembling all of the sections of strips or strips thus juxtaposed (s) to obtain a rigid element. It is remarkable by the fact that said operation is a stamping operation during which the metal is forced to creep towards the edges of the strip so as to create bosses therein, in the extension of said grooves. As will be seen later in the description, this process makes it possible, in the same step and with the same means, to form in the metal strip the channels for the flow of the gas / air mixture and the means for attaching the flame. . According to other advantageous but non-limiting characteristics of this process:
- on soumet ladite bande à une opération de poinçonnage de façon à former dans celle-ci au moins une série d'ouvertures ;- Said strip is subjected to a punching operation so as to form therein at least one series of openings;
- lesdites ouvertures ont une forme rectangulaire allongée et sont disposées dans le sens longitudinal de la bande ;- Said openings have an elongated rectangular shape and are arranged in the longitudinal direction of the strip;
- on juxtapose plusieurs tronçons par empilement ;- several sections are juxtaposed by stacking;
- on procède à l'enroulement d'une ou plusieurs bandes métalliques sur elle(s)-même(s), l'axe d'enroulement étant parallèle aux grandes faces de ladite (desdites) bande(s) ; - on procède à l'enroulement d'une ou plusieurs bandes métalliques sur elle(s)-même(s), l'axe d'enroulement étant perpendiculaire aux grandes faces de ladite (desdites) bande(s) ;- One proceeds to the winding of one or more metal strips on it (s) -same (s), the winding axis being parallel to the large faces of said (said) strip (s); - One proceeds to the winding of one or more metal strips on it (s) -same (s), the winding axis being perpendicular to the large faces of said (said) strip (s);
- l'opération de matπçage est effectuée à l'aide d'outils de formage rotatifs, tels qu'une molette nervurée et un contre-rouleau. - les rainures sont réalisées transversalement sur la bande ;- the matπasting operation is carried out using rotary forming tools, such as a ribbed wheel and a counter-roller. - The grooves are made transversely on the strip;
- les rainures sont réalisées obliquement sur la bande ;- the grooves are made obliquely on the strip;
- on réalise sur une même bande des rainures de largeurs différentes ;- Grooves of different widths are produced on the same strip;
- à l'étape b), on utilise des tronçons ou des bandes dont les rainures sont dirigées différemment et/ou dont les sections sont dif¬ férentes ;- In step b), sections or bands are used whose grooves are directed differently and / or whose sections are different;
- après l'étape a), on projette sur la bande une poudre d'alumine ou de chrome pur, cette projection ayant lieu à chaud ou à froid, et en ce que, à la suite de l'étape c), on soumet ledit élément à un chauffage de manière à provoquer la fusion de ladite poudre.- After step a), an alumina or pure chromium powder is sprayed onto the strip, this projection taking place hot or cold, and in that, following step c), it is subjected said element being heated so as to cause said powder to melt.
L'invention concerne également un élément de brûleur à gaz.The invention also relates to a gas burner element.
Cet élément de brûleur, du type formé d'une juxtaposition de tronçons de bandes ou de bandes appliqués les unes contre les autres, chaque tronçon ou bande ayant sur l'une de ses grandes faces une série de rainures débouchant sur ses rives, l'autre grande face étant lisse, la juxtaposition étant telle que leur face plane soit en contact avec la face rainuree du tronçon ou de la bande adjacente, se caractérise par le fait que les chants des bandes ou tronçons présentent des bossages situés dans le prolongement desdites rainures.This burner element, of the type formed by a juxtaposition of sections of strips or strips applied against each other, each section or strip having on one of its large faces a series of grooves opening onto its banks, the other large face being smooth, the juxtaposition being such that their flat face is in contact with the grooved face of the section or of the adjacent strip, is characterized by the fact that the edges of the strips or sections have bosses located in the extension of said grooves.
La multitude des passages du mélange air + gaz constitués par les rainures, et l'effet d'accroche-flamme des bossages (côté face de combustion) permettent d'obtenir d'excellentes performances sur le plan de la combustion. 0 De manière avantageuse, la juxtaposition consiste en un enroulement d'une ou plusieurs bandes métalliques sur elle(s)-même(s), l'axe d'enroulement étant perpendiculaire aux grandes faces de ladite (desdites) bande(s).The multitude of passages of the air + gas mixture formed by the grooves, and the flame-catching effect of the bosses (on the combustion face side) make it possible to obtain excellent performance in terms of combustion. 0 Advantageously, the juxtaposition consists of a winding of one or more metal strips on it (s) -same (s), the winding axis being perpendicular to the large faces of said (said) strip (s).
Selon un mode de réalisation particulièrement avantageux, -5 l'élément comporte plusieurs lignes de soudure sur sa surface externe ou interne, ces lignes étant équidistantes - ou sensiblement équidistantes - angulairement les unes des autres et disposées selon les génératrices de l'enroulement.According to a particularly advantageous embodiment, the element has several weld lines on its external or internal surface, these lines being equidistant - or substantially equidistant - angularly from one another and arranged along the generatrices of the winding.
L'invention concerne également un brûleur à gaz qui comporte 0 un tel élément.The invention also relates to a gas burner which includes such an element.
Selon un mode de réalisation avantageux, ledit élément est monté entre deux brides, chacune étant équipée d'un joint souple réfractaire pour la réception des extrémités de l'élément, de sorte que celui-ci peut se diiater librement, tout en étant maintenu entre les brides. ^ De préférence, le joint souple est formé de fibres de céramique.According to an advantageous embodiment, said element is mounted between two flanges, each being equipped with a flexible refractory seal for the reception of the ends of the element, so that the latter can diate freely, while being held between the flanges. ^ Preferably, the flexible joint is formed of ceramic fibers.
Il s'agit d'un brûleur dont la combustion superficielle est obtenue par une multitude de rainures dont la géométrie et la répartition est parfaitement régulière sur toute la surface et présentant une grande 0 perméabilité aux gaz. La structure même de cette surface comporte en outre différents points réguliers qui assurent un parfait "accrochage de la flamme" et donc une excellente stabilité de celle-ci.It is a burner whose surface combustion is obtained by a multitude of grooves whose geometry and distribution is perfectly regular over the entire surface and having a high gas permeability. The very structure of this surface also has various regular points which ensure perfect "attachment of the flame" and therefore excellent stability thereof.
L'épaisseur totale de la bande qui constitue le brûleur peut avoir une structure différente selon que l'on désire une flamme bleue ou 5 une combustion radiante. Les rainures qui traversent la bande sont, dans un cas, laminaires. Dans l'autre, elles traversent une "structure en labyrinthe" qui provoque une chute considérable de conductivité thermique entre la face exposée à la combustion et la face opposée, exposée aux gaz froids. D'autres caractéristiques et avantages de l'invention apparaî- tront de la description détaillée de quelques modes de réalisation préférentiels, description faite en référence aux dessins annexés dans lesquels :The total thickness of the strip which constitutes the burner may have a different structure depending on whether a blue flame or a radiant combustion is desired. The grooves which cross the strip are, in a cases, laminar. In the other, they pass through a "labyrinth structure" which causes a considerable drop in thermal conductivity between the face exposed to combustion and the opposite face, exposed to cold gases. Other characteristics and advantages of the invention will appear from the detailed description of some preferred embodiments, description made with reference to the accompanying drawings in which:
- la figure 1 est une vue schématique illustrant la mise en oeuvre de la première étape du procédé de l'invention ; - les figures 2A et 2B sont des vues respectivement de dessus et de côté d'une bande après la mise en oeuvre de la première étape du procédé ;- Figure 1 is a schematic view illustrating the implementation of the first step of the method of the invention; - Figures 2A and 2B are respectively top and side views of a strip after the implementation of the first step of the method;
- les figures 3 et sont des vues de dessus de deux variantes de cette bande ; - la figure 5 est une vue schématique illustrant une étape de poinçonnage facultative, pouvant être mise en oeuvre préalablement à la première étape illustrée à la figure 1 ;- Figures 3 and are top views of two variants of this strip; - Figure 5 is a schematic view illustrating an optional punching step, which can be implemented prior to the first step illustrated in Figure 1;
- la figure 6 est une vue schématique de dessus d'une bande obtenue conformément au procédé illustré à la figure 5 ; - la figure 7 est une vue schématique de côté d'un empilement de bandes métalliques conformes à celle représentée aux figures 2A et 2B ;- Figure 6 is a schematic top view of a strip obtained according to the method illustrated in Figure 5; - Figure 7 is a schematic side view of a stack of metal strips according to that shown in Figures 2A and 2B;
- la figure 8 est une vue de l'empilement de la figure 6, coupé transversalement par le plan brisé VIII-VIII de la figure 7 ;- Figure 8 is a view of the stack of Figure 6, cut transversely by the broken plane VIII-VIII of Figure 7;
- la figure 9 est une vue analogue à la figure 8, mais représentant un empilement de bandes de même type, soumises préalable¬ ment à un poinçonnage ;- Figure 9 is a view similar to Figure 8, but showing a stack of strips of the same type, subjected prior¬ ment punching;
- la figure 10 est une vue schématique de dessus d'un brûleur comportant un élément conforme à la présente invention ;- Figure 10 is a schematic top view of a burner comprising an element according to the present invention;
- la figure 1 1 est une vue schématique des moyens de mise en oeuvre d'un second mode de fabrication de l'élément de brûleur ;- Figure 1 1 is a schematic view of the means for implementing a second method of manufacturing the burner element;
- la figure 12 représente schématiquement la mise en oeuvre d'un troisième mode de fabrication d'un élément de brûleur ;- Figure 12 schematically shows the implementation of a third method of manufacturing a burner element;
- la figure 13 est une vue partielle en perspective d'un élément obtenu conformément au mode de fabrication de la figure 1 2 ; - la figure 14 est une vue en perspective de l'élément de la figure 1 3, sur lequel ont été réalisées des lignes de soudure ;- Figure 13 is a partial perspective view of an element obtained in accordance with the manufacturing method of Figure 1 2; - Figure 14 is a perspective view of the element of Figure 1 3, on which were made weld lines;
- la figure 1 5 représente partiellement, en coupe verticale d'un brûleur comportant un élément conforme à la figure 1 ; - la figure 1 6 est une vue de dessus, en coupe transversale du brûleur de la figure 15, selon le plan de coupe XVI-XVI ;- Figure 1 5 partially shows, in vertical section of a burner comprising an element according to Figure 1; - Figure 1 6 is a top view, in cross section of the burner of Figure 15, along the section plane XVI-XVI;
- la figure 17 est une vue agrandie d'une partie de la figure 15 ;- Figure 17 is an enlarged view of part of Figure 15;
- la figure 18 est une vue partielle analogue à celle de la figure 16, mais à plus grande échelle ;- Figure 18 is a partial view similar to that of Figure 16, but on a larger scale;
- la figure 19 est une vue de détail des moyens utilisés pour l'empilage de plusieurs éléments les uns sur les autres ;- Figure 19 is a detailed view of the means used for stacking several elements on top of each other;
- la figure 20 est une vue en perspective d'un autre mode de réalisation de brûleur ; - la figure 21 est une vue de détail d'une partie du brûleur de la figure 20.- Figure 20 is a perspective view of another embodiment of the burner; FIG. 21 is a detailed view of part of the burner in FIG. 20.
La première étape du procédé de l'invention va maintenant être décrite en référence à la figure 1.The first step of the method of the invention will now be described with reference to FIG. 1.
Cette étape est mise en oeuvre au moyen d'une molette rotative 2, d'un contre-rouleau 2' et de galets de guidage G et G'.This step is implemented by means of a rotary wheel 2, a counter-roller 2 'and guide rollers G and G'.
Une bande métallique 1 , de préférence en acier inoxydable ou en aluminium est soumise, lors de cette étape, à une opération de matπçage, à froid, avec fluage de la matière écrasée par la molette. A titre indicatif, la bande 1 présente une largeur de 6 mm et une épaisseur de 0,5 mm. Cette largeur correspond à l'épaisseur de l'élément de brûleur que l'on souhaite obtenir.A metal strip 1, preferably made of stainless steel or aluminum, is subjected, during this step, to a cold stamping operation, with creep of the material crushed by the wheel. As an indication, the strip 1 has a width of 6 mm and a thickness of 0.5 mm. This width corresponds to the thickness of the burner element that one wishes to obtain.
Les galets G et G' sont rotatifs et assurent le guidage de la bande métallique 1 dans le sens i en direction de la molette 2 et du contre-rouleau 2'. Des moyens appropriés assurent l'entraînement en rotation et en continu de ces derniers. Ils n'ont pas été représentés afi n de ne pas surcharger inutilement la figure.The rollers G and G 'are rotary and guide the metal strip 1 in the direction i in the direction of the wheel 2 and of the counter-roller 2'. Appropriate means ensure the continuous and rotary drive of the latter. They have not been represented in order not to unnecessarily overload the figure.
La molette 2, dont le sens de rotation a été symbolisé par la flèche g, est un rouleau cylindrique métallique qui présente des reliefs (dents) 20 et 21 à sa périphérie. Sur la figure, ces reliefs ont été dimensionnellement exagérés pour permettre de mieux comprendre la façon dont est mis en oeuvre l'étape du procédé. Dans cet exemple, la molette présente deux séries alternées de reliefs de hauteur différente qui s'étendent transversalement sur toute sa périphérie. Comme on le voit clairement sur cette figure, les reliefs consistent en des nervures parallèles, à bord libre arrondi (semi-cylindrique). Selon l'invention, la bande 1 est guidée, dans le sens de la flèche _f_ entre les galets G et G' puis forcée entre la molette et le contre rouleau 2', ce dernier étant mis en rotation dans le sens de la flèche h_. On opère ainsi un matriçage à froid de la bande, au cours duquel la matière située au droit des reliefs est comprimée et écrasée dans son épaisseur, de sorte que le surplus de matière est forcé de fluer latéralement, vers les chants de la bande. A l'issue de ce traitement, la bande 1 présente sur sa grande face supérieure 1 1 une série de canaux ou rainures transversales 4 et 4' dont la forme est sensiblement complémentaire de celle des nervures 20 et 21. Sa face inférieure est plane.The wheel 2, whose direction of rotation has been symbolized by the arrow g, is a cylindrical metal roller which has reliefs (teeth) 20 and 21 at its periphery. In the figure, these reliefs have been dimensionally exaggerated to allow a better understanding of the way in which the process step is implemented. In this example, the wheel has two alternating series of reliefs of different height which extend transversely over its entire periphery. As can clearly be seen in this figure, the reliefs consist of parallel ribs, with a rounded free edge (semi-cylindrical). According to the invention, the strip 1 is guided in the direction of the arrow _f_ between the rollers G and G 'then forced between the wheel and the counter roller 2', the latter being rotated in the direction of the arrow h_ . A cold stamping of the strip is thus carried out, during which the material located in line with the reliefs is compressed and crushed in its thickness, so that the excess material is forced to creep laterally, towards the edges of the strip. At the end of this treatment, the strip 1 has on its large upper face 1 1 a series of channels or transverse grooves 4 and 4 'whose shape is substantially complementary to that of the ribs 20 and 21. Its lower face is flat.
Les figures 2A et 2B présentent en détail l'aspect d'une portion de bande métallique traitée. Comme le montrent ces figures, le fond des rainures 4 et 4' a une section en forme d'arc de cercle. A titre indicatif, le diamètre des cercles correspondants est respectivement de 0,25 et 0,15 mm. D'autres formes de section peuvent être prévues, notamment rectangulaires.FIGS. 2A and 2B show in detail the appearance of a portion of treated metal strip. As these figures show, the bottom of the grooves 4 and 4 ′ has a section in the shape of an arc of a circle. As an indication, the diameter of the corresponding circles is respectively 0.25 and 0.15 mm. Other cross-sectional shapes can be provided, in particular rectangular.
Comme mentionné plus haut, lors du traitement de matriçage à froid, du fait que la matière même de la bande est emprisonnée et comprimée entre la molette 2 et le contre rouleau 2', le métal déplacé par les nervures 20 et 21 est contraint de fluer vers les rives de la bande. Aucun outil ne contrarie ce phénomène de fluage. Ceci se traduit par la création de bossages latéraux 40 et 40' qui se forment dans le prolon¬ gement des rainures 4 et 4'. Bien entendu, la matière déplacée pour créer les rainures 4 (les plus profondes) est plus importante que celle nécessaire à former les rainures 4', si bien que les bossages 40 sont plus grands que les bossages 40'. On comprendra plus loin le rôle et l'intérêt de ces bossages dans l'élément de brûleur que cette bande métallique est destinée à former. Bien entendu, la forme, les dimensions et l'espacement des reliefs constitutifs de la denture de la molette sont choisis en fonction des caractéristiques souhaitées pour la bande métallique matπcée.As mentioned above, during the cold stamping treatment, since the very material of the strip is trapped and compressed between the wheel 2 and the counter roller 2 ′, the metal displaced by the ribs 20 and 21 is forced to creep towards the banks of the strip. No tool counteracts this creep phenomenon. This results in the creation of lateral bosses 40 and 40 'which form in the extension of the grooves 4 and 4'. Of course, the material displaced to create the grooves 4 (the deepest) is greater than that necessary to form the grooves 4 ', so that the bosses 40 are larger than the bosses 40'. We will understand later the role and the interest of these bosses in the burner element that this metal strip is intended to form. Of course, the shape, the dimensions and the spacing of the reliefs constituting the teeth of the thumbwheel are chosen according to the characteristics desired for the matπcé metal strip.
Ainsi, à la figure 3, on a représenté une portion de bande 1 qui présente une série de rainures ou canaux transversaux 50 tous de même section. Corrélativement, les bossages formés aux deux extrémités des canaux sont également identiques.Thus, in Figure 3, there is shown a strip portion 1 which has a series of grooves or transverse channels 50 all of the same section. Correspondingly, the bosses formed at the two ends of the channels are also identical.
La bande 1 représentée à la figure 4 comporte, quant à elle, une série de rainures 5' disposées en oblique, c'est-à-dire légèrement inclinées par rapport à la direction transversale avec, à chacune de leurs extrémités, un bossage 50'. Il est bien entendu possible de choisir l'orientation des rainures que l'on souhaite obtenir.The strip 1 shown in FIG. 4 comprises, for its part, a series of grooves 5 ′ arranged obliquely, that is to say slightly inclined relative to the transverse direction with, at each of their ends, a boss 50 '. It is of course possible to choose the orientation of the grooves that one wishes to obtain.
A l'issue de cette étape, il est possible de fractionner la bande 1 en plusieurs tronçons, à l'aide d'un dispositif de coupe comprenant des outils M_, tels que des lames de cisaillage par exemple.At the end of this step, it is possible to split the strip 1 into several sections, using a cutting device comprising tools M_, such as shearing blades for example.
Dans une variante de réalisation du procédé de l'invention illustrée à la figure 5, on soumet la bande, préalablement au matriçage, à une opération de poinçonnage, à l'aide d'un outil 3 et d'une matrice 3'. Ces outils sont destinés à former dans la bande une série de perforations. Dans l'exemple représenté, l'outil 3 comporte trois poinçonsIn an alternative embodiment of the method of the invention illustrated in FIG. 5, the strip is subjected, before stamping, to a punching operation, using a tool 3 and a matrix 3 '. These tools are intended to form a series of perforations in the strip. In the example shown, tool 3 has three punches
30 et la matrice 3' comporte trois empreintes 30' de forme complémen¬ taires. Des déplacements successifs de l'outil 3 dans le sens de la double flèche _v permettent d'obtenir des perforations dans la bande 1. Le déplacement de cette bande est fait dans le sens de la flèche i_ à l'aide de rouleaux d'entraînement 31. Ce déplacement est opéré en discontinu, à chaque fois du pas w.30 and the matrix 3 ′ has three imprints 30 ′ of complementary shape. Successive displacements of the tool 3 in the direction of the double arrow _v make it possible to obtain perforations in the strip 1. The displacement of this strip is made in the direction of the arrow i_ using drive rollers 31. This displacement is carried out discontinuously, each time step w.
La bande est alors soumise à l'opération de matriçage décrite en référence à la figure 1.The strip is then subjected to the stamping operation described with reference to FIG. 1.
Selon la figure 6, ces perforations 12 et 1 3 sont des fentes réparties selon deux lignes parallèles aux grands côtés de la bande et ont la forme de rectangles allongés séparés par une petite quantité de matière.According to Figure 6, these perforations 12 and 1 3 are slots distributed along two lines parallel to the long sides of the strip and have the shape of elongated rectangles separated by a small amount of material.
Il est bien entendu possible de remplacer l'outil 3, et la matrice 3', par des outils de poinçonnage rotatifs remplissant les mêmes fonctions et permettant d'assurer une cadence de production plus élevée, du fait de la possibilité de réaliser simultanément et en continu l'opération de matriçage.It is of course possible to replace the tool 3, and the die 3 ′, by rotary punching tools filling the same functions and making it possible to ensure a higher production rate, due to the possibility of simultaneously and continuously carrying out the stamping operation.
Le nombre et la forme des perforations 12 et 1 3 peuvent bien entendu varier. Ainsi, une bande peut comporter par exemple quatre lignes de perforations. On expliquera plus loin l'intérêt de celles-ci.The number and shape of the perforations 12 and 1 3 can of course vary. Thus, a strip can comprise for example four lines of perforations. The interest of these will be explained later.
Dans un premier mode possible de mise en oeuvre, la seconde étape du procédé de l'invention consiste à juxtaposer et assembler plusieurs portions de bande de sorte que ces portions soient en contact par leurs grandes faces.In a first possible mode of implementation, the second step of the method of the invention consists in juxtaposing and assembling several portions of strip so that these portions are in contact by their large faces.
Cette étape est décrite plus spécifiquement en référence aux figures 7 et 8.This step is described more specifically with reference to FIGS. 7 and 8.
Bien entendu, cette étape est mise en oeuvre après que la bande rainuree 1 représentée aux figures 2A et 2B ait été fractionnée en plusieurs tronçons, de même longueur. On juxtapose alors plusieurs tronçonsOf course, this step is implemented after the grooved strip 1 shown in FIGS. 2A and 2B has been divided into several sections, of the same length. We then juxtapose several sections
100 les uns contre les autres de telle façon que leurs grandes faces 10 et 1 1 viennent en appui mutuel.100 against each other so that their large faces 10 and 1 1 come into mutual support.
Comme le montre la figure 7, la face 1 1 rainuree d'un tronçon étant en contact avec la face 10 du tronçon adjacent, il se crée entre les deux bandes une série de passages de sections différentes, débouchant sur chaque rive.As shown in Figure 7, the grooved face 1 1 of a section being in contact with the face 10 of the adjacent section, it creates between the two strips a series of passages of different sections, opening on each bank.
Les deux faces 101 et 102 correspondant aux rives - ou chants - de cet assemblage ont un aspect de surface irrégulier, dû à la présence des bossages 40 et 40'. A la figure 9, on a représenté un assemblage de plusieurs tronçons 100 provenant d'une bande préalablement poinçonnée, telle que celle de la figure 6. Ces portions présentent des rainures 5 de même section. Bien entendu, elles pourraient comporter des rainures de sections et d'orientations différentes. Les rainures qui traversent la bande rencontrent des perforations 12 et 13 qui, accolées les unes aux autres, constituent une structure en labyrinthe.The two faces 101 and 102 corresponding to the edges - or edges - of this assembly have an irregular surface appearance, due to the presence of the bosses 40 and 40 '. In Figure 9, there is shown an assembly of several sections 100 from a previously punched strip, such as that of Figure 6. These portions have grooves 5 of the same section. Of course, they could have grooves of different sections and orientations. The grooves which cross the strip meet perforations 12 and 13 which, joined to one another, constitute a labyrinth structure.
Selon la troisième étape du procédé de l'invention, on assemble les tronçons 1 00 pour obtenir un élément rigide. Cette opération peut être effectuée par exemple en solidarisant les extrémités des tronçons à une plaquette de fixation.According to the third step of the method of the invention, the sections 1 00 are assembled to obtain a rigid element. This operation can be performed for example by securing the ends of the sections to a fixing plate.
La figure 10 représente schématiquement en vue de dessus un brûleur à gaz qui est équipé d'un élément conforme à la présente invention. Ce brûleur 6 comporte une embase 60 de forme sensiblement parailèlé- pipèdique dont la face supérieure est partiellement ouverte. Cette ouverture (non visible) présente des dimensions adaptées pour recevoir, sans jeu notable, une plaque 1 03 formée d'un assemblage de portions de bandes métalliques retenues entre elles par des plaquettes d'extrémités 61. Sur l'une des faces latérales de l'embase 60 est connecté un conduit 62 d'amenée de mélange air/gaz. Ce mélange est amené jusqu'à la face inférieure de la plaque 103 et peut s'écouler librement au travers de celle-ci par les rainures qu'elle comporte.Figure 10 schematically shows a top view of a gas burner which is equipped with an element according to the present invention. This burner 6 includes a base 60 of substantially parallelail-piped shape, the upper face of which is partially open. This opening (not visible) has dimensions adapted to receive, without significant play, a plate 1 03 formed of an assembly of portions of metal strips held together by end plates 61. On one of the side faces of the base 60 is connected a conduit 62 for supplying air / gas mixture. This mixture is brought to the underside of the plate 103 and can flow freely through the latter through the grooves which it comprises.
Selon un autre mode de mise en oeuvre du procédé, la seconde étape de celui-ci consiste à juxtaposer plusieurs bandes métalliques rainurées en les enroulant sur elles-mêmes de façon à obtenir une plaque en forme de disque.According to another embodiment of the method, the second step of it consists in juxtaposing several grooved metal strips by winding them on themselves so as to obtain a disc-shaped plate.
Dans l'exemple de la figure 1 1 , on enroule simultanément sur elles-mêmes trois bandes 1, 1 ' et 1". Ces bandes sont guidées entre des molettes référencées 2, 7 etIn the example of FIG. 11, three bands 1, 1 ′ and 1 "are wound simultaneously on themselves. These bands are guided between knurled wheels referenced 2, 7 and
8 et des contre-rouleaux 2', 7' et 8'. Les portions de bande ayant subi l'opération de rainurage et, éventuellement, de poinçonnage, sont guidées entre des galets 20, 20', 70, 70' et 80, 80'. Les bandes sont ensuite dirigées autour d'un mandrin rotatif 97 dont le sens de rotation est repéré par la flèche k. L'enroulement est obtenu de telle sorte que l'axe d'enroulement 970 du mandrin soit parallèle aux grandes faces des bandes. L'enroulement obtenu a la forme d'un disque. Les rainures formées dans les bandes sont parallèles à l'axe du disque.8 and 2 ', 7' and 8 'counter rollers. The strip portions having undergone the grooving and, optionally, punching operation, are guided between rollers 20, 20 ', 70, 70' and 80, 80 '. The strips are then directed around a rotary mandrel 97 whose direction of rotation is identified by the arrow k. The winding is obtained in such a way that the winding axis 970 of the mandrel is parallel to the large faces of the strips. The winding obtained has the shape of a disc. The grooves formed in the strips are parallel to the axis of the disc.
Il est bien entendu possible de mettre en oeuvre cette étape du procédé en enroulant sur elle-même une seule bande, ou en enroulant simultanément un nombre différent de bandes, par exemple deux ou quatre. Il est également possible de soumettre chacune des bandes au traitement d'une molette présentant des reliefs différents. A titre indicatif, les bandes 1 , 1 ', 1" peuvent comporter respectivement des rainures telles que celles représentées aux figures 2, 3 et 4. Dans la variante de réalisation de la figure 12, la bande 1 est cintrée puis enroulée autour d'un mandrin rotatif 98 d'axe 99, de telle sorte que les grandes faces de cette bande soient perpendiculaires à l 'axe 99. On obtient alors un élément 106 annulaire (figure 13), de forme cylndπque constitué d'un enroulement hélicoïdal. Dans la présente variante les rainures formées dans les bandes s'étendent radialement (c'est-à-dire perpendiculairement à l'axe de l'enroulement), ou sont légèrement inclinées par rapport à la direction radiale si on a affaire à un matriçage "oblique" du genre représenté à la figure 4. Les passages formés par ces nervures relient l'une à l'autre les surfaces de paroi cylindriques intérieure et extérieure de l'enroulement. De la même manière que précédemment, il est possible d'enrouler simultanément plusieurs bandes matπcees dont les spires s'imbriquent alternativement les unes dans les autres (enroulement à pas multiple), les différentes bandes ayant des profils de rainures identiques ou différents.It is of course possible to implement this step of the method by winding a single strip on itself, or by simultaneously winding a different number of strips, for example two or four. It is also possible to subject each of the bands to the treatment of a wheel having different reliefs. As an indication, the strips 1, 1 ′, 1 ″ may respectively have grooves such as those shown in FIGS. 2, 3 and 4. In the alternative embodiment of FIG. 12, the strip 1 is bent and then wound around a rotary mandrel 98 of axis 99, so that the large faces of this strip are perpendicular to the axis 99. We then obtain an annular element 106 (FIG. 13), of cylindrical shape consisting of a helical winding. In the present variant, the grooves formed in the bands extend radially (that is to say perpendicular to the axis of the winding), or are slightly inclined relative to the radial direction if we are dealing with a stamping. "oblique" of the kind shown in Figure 4. The passages formed by these ribs connect to each other the inner and outer cylindrical wall surfaces of the winding. In the same way as previously, it is possible to simultaneously wind several matπcees bands whose turns are nested alternately one in the other (multiple pitch winding), the different bands having identical or different groove profiles.
Cette opération est facilitée si l'on utilise une (ou plusieurs) bande(s) pomçonnée(s). En effet, la présence de perforations améliore l'aptitude de la (ou des) bande(s) à la déformation. Un tel élément de brûleur peut être utilisé par exemple en combinaison avec un échangeur de chaleur de forme cylindrique, le brûleur étant placé en son centre.This operation is facilitated if one (or more) squeezed strip (s) is used. Indeed, the presence of perforations improves the suitability of the strip (s) for deformation. Such a burner element can be used for example in combination with a cylindrical heat exchanger, the burner being placed in its center.
La fabrication de l'élément est complétée enfin par une fixation mutuelle des spires de l'enroulement, par soudage.The manufacture of the element is finally completed by a mutual fixing of the turns of the winding, by welding.
L'élément 106 représenté à la figure 14 a reçu plusieurs lignes ou cordons de soudure 107 au niveau de sa surface de paroi extérieure ou intérieure (non représentée). Ces lignes de soudure s'étendent selon des génératrices de l'élément annulaire cylindrique 106 et sont équidistantes anguiairement les unes des autres.The element 106 shown in FIG. 14 has received several weld lines or beads 107 at its exterior or interior wall surface (not shown). These weld lines extend along generatrices of the cylindrical annular element 106 and are angularly equidistant from each other.
Les lignes de soudure peuvent être réalisées à l'aide d'un fil d'acier inoxydable en utilisant une molette, à l'aide de la technique dite "Tig" (En anglais : Tungsten inert gaz) ou "Mig", ou au laser.The weld lines can be made using a stainless steel wire using a thumbwheel, using the so-called "Tig" technique (In English: Tungsten inert gaz) or "Mig", or at laser.
Ces soudures permettent de garantir à la fois un contact permanent entre les spires de l'enroulement qui forment l 'élément 106 et la rigidité de l'élément lui-même.These welds make it possible to guarantee both permanent contact between the turns of the winding which form the element 106 and the rigidity of the element itself.
Le nombre de lignes de soudure doit être raisonnable par rapport au diamètre de l'élément. Ainsi, par exemple, on réalise huit lignes de soudure pour un élément ayant un diamètre extérieur de 126 mm. La pénétration du matériau de soudure dans l'élément doit, de préférence, rester faible pour ne pas provoquer de contraintes mécaniques importantes. Ainsi, cette pénétration ne dépasse avantageusement pas un tiers de la largeur des bandes qui constituent l'élément. Aux figures 1 5 à 18 est représenté un brûleur à gaz équipé d'un élément 106 conforme à la description qui vient d'être faite.The number of weld lines must be reasonable in relation to the diameter of the element. Thus, for example, eight weld lines are produced for an element having an outside diameter of 126 mm. The penetration of the weld material into the element should preferably remain low so as not to cause significant mechanical stresses. Thus, this penetration advantageously does not exceed one third of the width of the bands which constitute the element. Figures 1 5 to 18 is shown a gas burner equipped with an element 106 according to the description which has just been made.
L'élément 106, d'axe XX', est intercalé entre deux brides 61 ', 60'.The element 106, of axis XX ', is interposed between two flanges 61', 60 '.
La bride inférieure 61 ' est un disque de faible épaisseur ; elle présente un bord 61 1 ' relevé à angle droit vers le haut qui délimite extérieurement une gorge annulaire 610'.The lower flange 61 'is a thin disc; it has an edge 61 1 'raised at a right angle upward which externally delimits an annular groove 610'.
Contre le rebord 61 1 ' est placé un joint annulaire souple 65', par exemple en fibres de céramique ayant une section en "L" dont les ailes s'appliquent respectivement contre le bord 61 1 ' et contre le fond de la gorge 610'.Against the rim 61 1 'is placed a flexible annular seal 65', for example made of ceramic fibers having an "L" section whose wings are applied respectively against the edge 61 1 'and against the bottom of the groove 610' .
Sur le disque 61 ', au niveau de la gorge 610 et à l'intérieur du joint 65', sont fixés, selon un cercle imaginaire, une série de tirants métallique 64' de section circulaire, parallèles à XX'.On the disc 61 ′, at the level of the groove 610 and inside the seal 65 ′, are fixed, according to an imaginary circle, a series of metal tie rods 64 ′ of circular section, parallel to XX ′.
Les tirants sont fixés au disque par tout moyen approprié, par exemple au moyen de vis (non représentées).The tie rods are fixed to the disc by any suitable means, for example by means of screws (not shown).
La bride supérieure 60' a la forme d'une couronne épaisse. Sa face inférieure présente une gorge annulaire 600' qui reçoit un joint souple 66' analogue au joint 65' mais de section en "U". Elle comporte également une série d'alésages non représentés, pour l'emboîtement, sans jeu notable, de l'extrémité supérieure des tirants 64'. Cet emboîtement est complété par une fixation (par exemple au moyen de vis).The upper flange 60 'has the shape of a thick crown. Its underside has an annular groove 600 'which receives a flexible seal 66' similar to the seal 65 'but of "U" section. It also includes a series of bores, not shown, for fitting, without significant play, the upper end of the tie rods 64 ′. This interlocking is completed by a fixing (for example by means of screws).
La disposition de la gorge 600' est telle que lorsque la bride 60' est en place sur les tirants 64', les joints 65' et 66' sont à l'aplomb l'un de l'autre. Entre les brides 60' et 61 ' est monté l'élément 106 dont les faces d'extrémité supérieure et inférieure sont en contact avec les joints 65' et 66', sans pour autant qu'il y ait un serrage excessif de l 'élément entre les joints. De préférence, le nombre de tirants 64' est égal au nombre de lignes de soudure de l'élément 106 et on fait correspondre les tirants avec les lignes des soudures afin qu'ils soient en face les uns des autres.The arrangement of the groove 600 ′ is such that when the flange 60 ′ is in place on the tie rods 64 ′, the seals 65 ′ and 66 ′ are plumb with each other. Between the flanges 60 'and 61' is mounted the element 106, the upper and lower end faces of which are in contact with the seals 65 'and 66', without there being excessive tightening of the element. between the joints. Preferably, the number of tie rods 64 ′ is equal to the number of weld lines of the element 106 and the tie rods are made to correspond with the lines of the welds so that they are opposite one another.
Le brûleur comporte également deux grilles cylindriques perforées 62' et 63' dont les diamètres respectifs sont tels qu'elles se répartissent de part et d'autre des tirants 64'.The burner also comprises two perforated cylindrical grids 62 'and 63' whose respective diameters are such that they are distributed on either side of the tie rods 64 '.
Seules quelques perforations 630' de la grille 63' ont été représentées sur les figures 1 5 et 17, pour ne pas alourdir inutilement ces figures.Only a few perforations 630 'of the grid 63' have been shown in Figures 1 5 and 17, so as not to unnecessarily burden these figures.
La grille 63' de plus petit diamètre se trouve à l'intérieur de la série de tirants 64'. La grille 62', de plus grand diamètre, est extérieure à ces derniers et présente une série de saillies 620' constituées par des plis en "V" s'étendant suivant des génératrices et dirigées vers l'extérieur, qui viennent en appui contre la paroi interne de l'élément 106 et permettent de maintenir un écartement constant entre ce dernier et la grille. Côté intérieur, les saillies maintiennent la grille centrée sur les tirants.The grid 63 'of smaller diameter is located inside the series of tie rods 64'. The grid 62 ′, of larger diameter, is external to the latter and has a series of projections 620 ′ constituted by “V” folds extending along generators and directed towards the outside, which bear against the internal wall of the element 106 and make it possible to maintain a constant spacing between the latter and the grid. On the inside, the projections keep the grid centered on the tie rods.
A la figure 19 est représenté un profilé annulaire, de section en forme de "H", qui permet d'empiler deux éléments 106 coaxialement l'un sur l'autre ; les gorges supérieure et inférieure de ce profilé reçoivent chacune un joint souple 68', respectivement 69', de section en "L", par exemple en fibres de céramique.In Figure 19 is shown an annular profile, of section in the shape of "H", which allows to stack two elements 106 coaxially one on the other; the upper and lower grooves of this profile each receive a flexible seal 68 ′, respectively 69 ′, of "L" section, for example made of ceramic fibers.
Le brûleur 6" de la figure 20 est équipé d'un élément 108 formé d'une juxtaposition de portions de bandes métalliques légèrement galbées. Chaque bande est formée d'un secteur d'élément de brûleur cylindrique annulaire conforme à celui de la figure 14, de grand diamètreThe burner 6 "of FIG. 20 is equipped with an element 108 formed by a juxtaposition of portions of slightly curved metal bands. Each band is formed by a sector of annular cylindrical burner element conforming to that of FIG. 14 , of large diameter
(et découpé longitudinalement suivant des génératrices).(and cut longitudinally along generators).
Les bandes, dont les rainures dues au matriçage sont référencées 1 13, sont retenues les unes contre les autres par des lignes de soudure 109 et les bords latéraux de l'élément sont insérés dans un cadre approprié 1 10 pourvu d'un joint souple 1 1 1.The strips, the grooves of which forging are referenced 1 13, are held against one another by weld lines 109 and the lateral edges of the element are inserted in a suitable frame 1 10 provided with a flexible seal 1 1 1.
Sous l'élément 107 est disposée une grille perforée 1 12 dont on expliquera plus loin la fonction.Under the element 107 is arranged a perforated grid 1 12 whose function will be explained below.
Nous allons maintenant expliquer le fonctionnement des éléments de brûleur de l'invention lors de la combustion d'un mélange air/gaz. Cette description sera faite, dans un premier temps, plus spécifiquement en référence à la figure 8.We will now explain the operation of the burner elements of the invention during the combustion of an air / gas mixture. This description will be made, firstly, more specifically with reference to FIG. 8.
Le mélange air/gaz A + G arrive au niveau de la face inférieure de la plaque constituée par l'assemblage des bandes métalliques et s'écoule de bas en haut par les canaux 4 et 4' de cette plaque. Du fait que ces canaux ont une petite section et une grande longueur, le corps de la plaque est relativement froid par rapport à la flamme.The air / gas mixture A + G arrives at the level of the lower face of the plate formed by the assembly of the metal strips and flows from bottom to top through the channels 4 and 4 'of this plate. Because these channels have a small section and a long length, the body of the plate is relatively cold compared to the flame.
Cette nette différence de température empêche les rentrées de flamme à l'intérieur du brûleur. La combustion s'opère au niveau de la face supérieure de la plaque dans la région repérée par la lettre C à la figure 8. Les bossages 40 et 40' qui bordent cette région de combustion constituent autant de protubérances chaudes qui créent des turbulences de surface et qui permettent d'accrocher la flamme. Bien entendu, les bossages 40, qui présentent une taille plus importante que celle des bossages 40' sont moins chauds. Toutefois, en alternant les canaux 4 et 4' la flamme est retenue par les petits bossages 40'. En quelque sorte, les petits bossages gardent la flamme rapprochée de la plaque du brûleur, d'autant mieux qu'ils présentent des plus petits débits de gaz que leurs voisins. En alternant des bandes ou des portions de bande avec des rainures orientées dans différentes directions, par exemple en alternant les bandes des figures 3 et 4, les différents courants d'air et de gaz provoquent des turbulences supplémentaires sur le site de combustion. Il s'opère donc une agitation des différents volumes élémentaires d'air et de gaz. Cette turbulence aléatoire de surface augmente la qualité de combustion.This clear difference in temperature prevents reentry of the flame inside the burner. The combustion takes place at the level of the upper face of the plate in the region marked by the letter C in FIG. 8. The bosses 40 and 40 ′ which border this combustion region constitute as many hot protuberances which create surface turbulences and which allow to hang the flame. Of course, the bosses 40, which have a larger size than that of the bosses 40 'are less hot. However, by alternating channels 4 and 4 ', the flame is retained by the small bosses 40'. In a way, the small bosses keep the flame close to the burner plate, all the better since they have smaller gas flow rates than their neighbors. By alternating strips or portions of strip with grooves oriented in different directions, for example by alternating the strips of Figures 3 and 4, the different air and gas streams cause additional turbulence on the combustion site. There is therefore an agitation of the various elementary volumes of air and gas. This random surface turbulence increases the quality of combustion.
Nous allons également décrire le fonctionnement d'une plaque conforme à celle de la figure 9.We will also describe the operation of a plate conforming to that of FIG. 9.
Lorsque le mélange air/gaz A + G arrive au niveau de la face inférieure de l'assemblage de bandes métalliques, les perforations 12 et 13 conduisent à une rupture de conductivité thermique dans l'épaisseur de l'assemblage, entre la face 104 exposée à la combustion et celle 105 exposée aux gaz froids. La face 104 exposée à la combustion s'élève alors en température - car elle n'est plus véritablement refroidie par les gaz froids - et devient radiante.When the air / gas mixture A + G arrives at the lower face of the assembly of metal strips, the perforations 12 and 13 lead to a break in thermal conductivity in the thickness of the assembly, between the face 104 exposed combustion and 105 exposed to cold gases. The face 104 exposed to combustion then rises in temperature - because it is no longer really cooled by the cold gases - and becomes radiant.
Toutefois, l'épaisseur de l'assemblage exposée à la flamme, située au-dessus des perforations 12 et 13 ne permet pas un retour de flamme vers les labyrinthes constitués par les couches de perforations, évitant ainsi toute combustion interstitielle dans ces labyrinthes, ce qui conduirait à des points chauds propices à augmenter la pollution, surtout les Nox et le CO.However, the thickness of the assembly exposed to the flame, located above the perforations 12 and 13 does not allow a flashback to the labyrinths formed by the layers of perforations, thus avoiding interstitial combustion in these labyrinths, this which would lead to hot spots conducive to increasing pollution, especially Nox and CO.
La zone formant labyrinthe constitue dans l'épaisseur du brûleur une zone de transition à faible conductivité thermique, entre la zone chaude et radiante et la zone froide.The labyrinth zone constitutes in the thickness of the burner a transition zone with low thermal conductivity, between the hot and radiant zone and the cold zone.
L'espace entre les perforations et la largeur de ceiles-ci définissent les dimensions des points qui seuls transmettent la chaleur d'une face 105 à l'autre 104. La largeur des fentes constitue le nombre de ces points.The space between the perforations and the width of the latter define the dimensions of the points which alone transmit heat from one face 105 to the other 104. The width of the slots constitutes the number of these points.
La température au niveau de la face 104 est trop élevée pour résister convenablement pendant des dizaines de milliers d'heures de fonctionnement, même en utilisant des aciers réfractaires. C'est pourquoi on peut soumettre les bandes, après leur matriçage, à une projection à chaud de poudre d'alumine ou de chrome pur, sur quelques microns d'épaisseur, avec un dispositif approprié. Cette projection peut également avoir lieu à froid, la poudre étant alors mélangée avec un liant. Après juxtaposition des bandes, on fait passer l'assemblage au four en atmosphère neutre ou sous-vide. Cela provoque la fusion de la poudre et sa diffusion dans le métal qui constitue les bandes. Le brûleur ainsi obtenu est parfaitement rigide, du fait des points de contact établis par la poudre fondue, et peut résister convenablement aux fortes températures.The temperature at face 104 is too high to resist adequately during tens of thousands of hours of operation, even when using refractory steels. This is why the strips can be subjected, after their stamping, to a hot spraying of alumina or pure chromium powder, a few microns thick, with an appropriate device. This spraying can also take place when cold, the powder then being mixed with a binder. After juxtaposition of the strips, the assembly is passed through the oven in a neutral atmosphere or under vacuum. This causes the powder to melt and diffuse into the metal that makes up the strips. The burner thus obtained is perfectly rigid, due to the contact points established by the molten powder, and can suitably withstand high temperatures.
Le fonctionnement du brûleur des figures 15 à 18 est le suivant.The operation of the burner in Figures 15 to 18 is as follows.
Un mélange air/gaz A + G est amené par le dessus du brûleur comme le montre la figure 15 et vient occuper l'espace intérieur délimité par la grille 63'. Le pourcentage d'ajours de cette grille est choisi de telle manière qu'il s'opère une détente globale du volume de mélange air/gaz. En d'autres termes, il se crée une pression sensiblement uniforme sur toute la hauteur du brûleur. La seconde grille 62' assure une bonne répartition du débit de mélange A + G vers l'élément de brûleur 106. L'espace intermédiaire entre les deux grilles permet de générer une seconde détente.An air / gas mixture A + G is brought in from above the burner as shown in FIG. 15 and occupies the interior space delimited by the grid 63 '. The percentage of openings in this grid is chosen such that there is an overall expansion of the volume of air / gas mixture. In other words, a substantially uniform pressure is created over the entire height of the burner. The second grid 62 ′ ensures a good distribution of the flow of mixture A + G towards the burner element 106. The intermediate space between the two grids makes it possible to generate a second expansion.
Ce mode de répartition du débit par l'emploi de grilles (tôles perforées) est bien connu en aéraulique et n'a pour but que d'améliorer le fonctionnement du brûleur.This mode of distributing the flow by the use of grids (perforated sheets) is well known in aeraulics and is only intended to improve the operation of the burner.
Au cours de la combustion du mélange A + G, l'élément 106 a tendance à se dilater, aussi bien en longueur que selon son diamètre. Le phénomène n'est pas contrarié, du fait que l'élément est intercalé entre deux joints souples. L'élément de brûleur peut donc se déformer librement, la cohésion de l'ensemble étant de toute façon assurée par les lignes de soudure, dont la dilatation suit celle des bandes métalliques.During the combustion of the A + G mixture, the element 106 tends to expand, both in length and according to its diameter. The phenomenon is not thwarted, because the element is interposed between two flexible seals. The burner element can therefore deform freely, the cohesion of the assembly being in any case ensured by the weld lines, the expansion of which follows that of the metal strips.
Le mélange air/gaz traverse radiaiement les passages entre spires de l'enroulement 106, et la combustion se fait sur la surface externe de l'élément de brûleur, les bossages garnissant ladite surface favorisant l'accrochage des flammes, comme cela a été expliqué plus haut en référence au mode de réalisation de la figure 8.The air / gas mixture radially crosses the passages between the turns of the winding 106, and the combustion takes place on the external surface of the burner element, the bosses lining said surface promoting the attachment of the flames, as has been explained. above with reference to the embodiment of FIG. 8.
Le fonctionnement du brûleur de la figure 20 est sensiblement le même que celui décrit plus haut. La grille 1 12 sert à la bonne répartition du mélange A + G. Cette dernière, qui est galbée comme l'élément de brûleur 108 lui-même, a tendance à se déformer (par dilatation thermique) comme ce dernier, en accentuant encore son galbe.The operation of the burner in FIG. 20 is substantially the same as that described above. The grid 1 12 is used for the correct distribution of the mixture A + G. The latter, which is curved like the burner element 108 itself, tends to deform (by thermal expansion) like the latter, further accentuating its curved.
Avec la technique de fabrication de la présente invention, on peut réaliser dans les bandes de toutes petites rainures aptes à assurer chacune un très faible débit de mélange air/gaz dans des proportions voisines du mélange stoechiométπque parfait. De cette manière, on se rapproche de la combustion la plus performante.With the manufacturing technique of the present invention, it is possible to produce in the strips very small grooves each capable of ensuring a very low flow rate of air / gas mixture in proportions close to the perfect stoichiometric mixture. In this way, we get closer to the most efficient combustion.
On remarquera qu'avec le procédé de la présente invention, dans une même opération, on réalise les canaux propices à l'écoulement du mélange d'air/gaz mais également les reliefs qui permettent d'accrocher la flamme à la surface supérieure du brûleur.It will be noted that with the method of the present invention, in the same operation, the channels conducive to the flow of the material are produced. mixture of air / gas but also the reliefs which allow the flame to hang on the upper surface of the burner.
On notera enfin que l'élément de la présente invention permet d'obtenir d'excellentes combustions même à des débits d'air et de gaz extrêmes.Finally, it will be noted that the element of the present invention makes it possible to obtain excellent combustions even at extreme air and gas flow rates.
Dans l'étape de matriçage du procédé, il est bien entendu possible d'utiliser plusieurs molettes nervurées (et plusieurs contre- rouleaux) travaillant à la suite de façon à réaliser progressivement les rainures dans les bandes. Ceci permet d'accélérer la cadence de production tout en augmentant la durée de vie des outils.In the mastering step of the process, it is of course possible to use several ribbed knurls (and several counter rollers) working in succession so as to progressively produce the grooves in the strips. This accelerates the production rate while increasing the life of the tools.
A titre indicatif, des essais de combustion ont été réalisés sur un brûleur conforme à celui des figures 15 à 18.As an indication, combustion tests were carried out on a burner conforming to that of FIGS. 15 to 18.
L'émission de CO est de l'ordre de 6 à 1 0 ppm, de sorte que l'hygiène de combustion est remarquable. L'émission de Nox (oxydes d'azotes) est de 2 à 8 ppm, ceci dans une plage de variation de puissance de 5 à 30 kW pour un élément de brûleur de 126 mm de diamètre et 120 mm de longueur. Ces résultats se situent largement en-dessous des limites imposées par les labels écologiques européens les plus sévères. En empilant plusieurs éléments de brûleur conformes à la figure 14 à l'aide de profilés tels que décrits à la figure 19, on peut réaliser des brûleurs de forte puissance. Celle-ci peut être modulée en fonction du diamètre et de la longueur de chaque élément. The CO emission is of the order of 6 to 10 ppm, so that the combustion hygiene is remarkable. The emission of Nox (nitrogen oxides) is 2 to 8 ppm, this in a range of power variation from 5 to 30 kW for a burner element of 126 mm in diameter and 120 mm in length. These results are far below the limits imposed by the most stringent European ecological labels. By stacking several burner elements in accordance with FIG. 14 using profiles as described in FIG. 19, high-power burners can be produced. This can be adjusted according to the diameter and the length of each element.

Claims

I SREVENDICATIONS I SREVENDICATIONS
1. Procédé de fabrication d'un élément de brûleur à gaz selon lequel : a) on soumet au moins une bande métallique ( 1 , 1 ', 1 ") dont la largeur correspond à l'épaisseur de l'élément de brûleur à obtenir à une opération visant à former dans l'une de ses grandes faces ( 1 1 ) une série de rainures (4, 4', 5, 5') débouchant sur ses rives, l'autre grande face ( 10) de la bande étant maintenue lisse ; b) on juxtapose plusieurs tronçons ( 100) de cette bande métallique ( 1 , 1 ', 1 "), ou plusieurs bandes métalliques, pour les appliquer ies uns (les unes) contre les autres de telle manière que leur face plane ( 10) soit en contact avec la face rainuree ( 1 1 ) du tronçon ou de la bande adjacente, et inversement ; c) on assemble l'ensemble des tronçons ( 100) de bandes ou des bandes ( 1 , 1 ', 1") ainsi juxtaposé(e)s pour obtenir un élément rigide, caractérisé en ce que ladite opération est une opération de matriçage au cours de laquelle on contraint le métal à fluer vers les chants de la bande de façon à y créer des bossages (40, 40', 50, 50'), dans le prolongement desdites rainures.1. Method for manufacturing a gas burner element according to which: a) at least one metal strip (1, 1 ′, 1 ") is subjected, the width of which corresponds to the thickness of the burner element to be obtained in an operation aimed at forming in one of its large faces (1 1) a series of grooves (4, 4 ', 5, 5') opening on its banks, the other large face (10) of the strip being kept smooth; b) several sections (100) of this metal strip (1, 1 ′, 1 "), or several metal strips, are juxtaposed to apply them one against the other so that their flat face (10) is in contact with the grooved face (1 1) of the section or of the adjacent strip, and vice versa; c) assembling all of the sections (100) of strips or strips (1, 1 ′, 1 ") thus juxtaposed to obtain a rigid element, characterized in that said operation is a die-forging operation using during which the metal is forced to creep towards the edges of the strip so as to create bosses (40, 40 ', 50, 50'), in the extension of said grooves.
2. Procédé selon la revendication 1 , caractérisé en ce que, préalablement à l'étape a), on soumet ladite bande à une opération de poinçonnage de façon à former dans celle-ci au moins une série d'ouvertures ( 12, 13).2. Method according to claim 1, characterized in that, prior to step a), said strip is subjected to a punching operation so as to form therein at least one series of openings (12, 13) .
3. Procédé selon la revendication 2, caractérisé en ce que lesdites ouvertures ( 12, 13) ont une forme rectangulaire allongée et sont disposées dans le sens longitudinal de la bande.3. Method according to claim 2, characterized in that said openings (12, 13) have an elongated rectangular shape and are arranged in the longitudinal direction of the strip.
4. Procédé selon l'une des revendications 1 à 3, caractérisé en ce que à l'étape b), on juxtapose plusieurs tronçons { 100) par empilement.4. Method according to one of claims 1 to 3, characterized in that in step b), several sections (100) are juxtaposed by stacking.
5. Procédé selon l'une des revendications 1 à 3, caractérisé en ce que, à l'étape b), on procède à l'enroulement d'une ou plusieurs bandes métalliques ( 1 , 1 ', 1") sur eile(s)-même(s), l'axe d'enroulement (970) étant parallèle aux grandes faces de ladite (desdites) bande(s).5. Method according to one of claims 1 to 3, characterized in that, in step b), one or more metallic strips (1, 1 ', 1 ") are wound on the eye ( s) -same (s), the winding axis (970) being parallel to the large faces of said (said) strip (s).
6. Procédé selon l'une des revendications 1 à 3, caractérisé en ce que, à l'étape b), on procède à l'enroulement d'une ou plusieurs bandes métalliques ( 1 , 1 ', 1 ") sur elle(s)-même(s), l'axe d'enroulement (99) étant perpendiculaire aux grandes faces de ladite (desdites) bande(s).6. Method according to one of claims 1 to 3, characterized in that, in step b), one or more strips are wound up. metal (1, 1 ', 1 ") on it (s) -same (s), the winding axis (99) being perpendicular to the large faces of said (said) strip (s).
7. Procédé selon l'une des revendications 1 à 6, caractérisé en ce que l'opération de matriçage est effectuée à l'aide d'outils de formage rotatifs, tels qu'une molette nervurée (2, 7, 8) et un contre-rouleau (2', 7', 8').7. Method according to one of claims 1 to 6, characterized in that the stamping operation is carried out using rotary forming tools, such as a ribbed wheel (2, 7, 8) and a counter roller (2 ', 7', 8 ').
8. Procédé selon l'une des revendications 1 à 7, caractérisé en ce que les rainures (4, 4') sont réalisées transversalement sur la bande.8. Method according to one of claims 1 to 7, characterized in that the grooves (4, 4 ') are formed transversely on the strip.
9. Procédé selon l'une des revendications 1 à 7, caractérisé en ce que les rainures (4, 4') sont réalisées obliquement sur la bande.9. Method according to one of claims 1 to 7, characterized in that the grooves (4, 4 ') are produced obliquely on the strip.
10. Procédé selon l'une des revendications 1 à 9, caractérisé en ce qu'on réalise sur une même bande des rainures (4, 4') de largeurs différentes.10. Method according to one of claims 1 to 9, characterized in that grooves (4, 4 ') of different widths are produced on the same strip.
1 1. Procédé selon l'une des revendications 1 à 9, caractérisé en ce que, à l'étape b), on utilise des tronçons ( 100) ou des bandes ( 1 , 1 ', 1 ") dont les rainures (4, 4') sont dirigées différemment et/ou dont les sections sont différentes.1 1. Method according to one of claims 1 to 9, characterized in that, in step b), sections (100) or strips (1, 1 ', 1 ") are used, the grooves (4 , 4 ') are run differently and / or have different sections.
12. Procédé selon l'une des revendications 1 à 1 1 , caractérisé en ce que, après l'étape a), on projette sur la bande une poudre d'alumine ou de chrome pur, cette projection ayant lieu à chaud ou à froid, et en ce que, à la suite de l'étape c), on soumet ledit élément à un chauffage de manière à provoquer la fusion de ladite poudre.12. Method according to one of claims 1 to 1 1, characterized in that, after step a), a strip of pure alumina or chromium powder is sprayed onto the strip, this projection taking place hot or cold , and in that, following step c), said element is subjected to heating so as to cause the melting of said powder.
13. Elément de brûleur à gaz du type formé d'une juxtapo¬ sition de tronçons de bandes (100) ou de bandes ( 1 , 1 ', 1 ") appliqués ies unes contre les autres, chaque tronçon ou bande ayant sur l'une de ses grandes faces ( 1 1 ) une série de rainures (4, 4', 5, 5') débouchant sur ses rives, l'autre grande face (10) étant lisse, la juxtaposition étant telle que leur face plane (10) soit en contact avec la face rainuree ( 1 1 ) du tronçon ou de la bande adjacente, caractérisé en ce que les chants des bandes ou tronçons présentent des bossages (40, 40', 50, 50') situés dans le prolongement desdites rainures.13. Gas burner element of the type formed by a juxtapo¬ sition of sections of strips (100) or strips (1, 1 ', 1 ") applied ies against each other, each section or strip having on the one of its large faces (1 1) a series of grooves (4, 4 ', 5, 5') opening onto its banks, the other large face (10) being smooth, the juxtaposition being such that their planar face (10 ) is in contact with the grooved face (1 1) of the section or of the adjacent strip, characterized in that the edges of the strips or sections have bosses (40, 40 ', 50, 50') situated in the extension of said grooves .
14. Elément selon la revendication 13, caractérisé en ce que ladite juxtaposition consiste en un enroulement ( 1 06) d'une ou plusieurs bandes métalliques ( 1 , 1 ', 1 ") sur elle(s)-même(s), leur axe d'enroulement (99) étant perpendiculaire aux grandes faces de ladite (desdites) bande(s).14. Element according to claim 13, characterized in that said juxtaposition consists of a winding (1 06) of one or more metal strips (1, 1 ', 1 ") on it (s) -same, their winding axis (99) being perpendicular to the large faces of said (said) strip (s).
15. Elément selon la revendication 14, caractérisé en ce qu'il comporte plusieurs lignes de soudure ( 107) disposées sur sa surface externe ou interne selon les génératrices de l'enroulement ( 106), ces lignes étant sensiblement équidistantes angulairement les unes des autres.15. Element according to claim 14, characterized in that it comprises several weld lines (107) arranged on its external or internal surface along the generatrices of the winding (106), these lines being substantially equidistant angularly from each other .
16. Brûleur à gaz équipé d'un élément conforme à l'une des revendications 1 3 à 15.16. Gas burner equipped with an element according to one of claims 1 3 to 15.
17. Brûleur à gaz selon la revendication 1 6, caractérisé en ce que ledit élément ( 106) est monté entre deux brides (60', 61 '), chacune étant équipée d'un joint souple réfractaire (65, 66') pour la réception des extrémités de l'élément ( 106), de sorte que celui-ci peut se dilater librement, tout en étant maintenu entre les brides (60', 61 ').17. Gas burner according to claim 1 6, characterized in that said element (106) is mounted between two flanges (60 ', 61'), each being equipped with a flexible refractory seal (65, 66 ') for the receiving the ends of the element (106), so that it can expand freely, while being held between the flanges (60 ', 61').
18. Brûleur à gaz selon la revendication 17, caractérisé en ce que ledit joint souple (65, 66') est formé de fibres de céramique. 18. Gas burner according to claim 17, characterized in that said flexible seal (65, 66 ') is formed of ceramic fibers.
EP94904676A 1993-01-15 1994-01-14 Method for producing a gas burner element, burner element and burner using same Expired - Lifetime EP0679239B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
FR9300497A FR2700604B1 (en) 1993-01-15 1993-01-15 Method of manufacturing a gas burner element, element thus obtained, and burner using it.
FR9300497 1993-01-15
PCT/FR1994/000046 WO1994016269A1 (en) 1993-01-15 1994-01-14 Method for producing a gas burner element, burner element and burner using same

Publications (2)

Publication Number Publication Date
EP0679239A1 true EP0679239A1 (en) 1995-11-02
EP0679239B1 EP0679239B1 (en) 1996-08-14

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EP94904676A Expired - Lifetime EP0679239B1 (en) 1993-01-15 1994-01-14 Method for producing a gas burner element, burner element and burner using same

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EP (1) EP0679239B1 (en)
DE (1) DE69400373T2 (en)
ES (1) ES2091691T3 (en)
FR (1) FR2700604B1 (en)
WO (1) WO1994016269A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2740202B1 (en) * 1995-10-19 1997-12-12 Leblanc Sa E L M IMPROVEMENTS TO A WATER HEATER, BATH HEATER, GAS BOILER
NL1003311C2 (en) * 1996-06-10 1997-12-17 Radson Alutherm Nv Flame distribution device intended for a burner of a hot water appliance.
IT1292577B1 (en) * 1997-05-23 1999-02-08 Worgas Bruciatori Srl CYLINDRICAL GAS BURNER.
RU2144160C1 (en) * 1999-04-15 2000-01-10 Липовый Николай Максимович Converter
JP3996139B2 (en) * 2004-03-29 2007-10-24 リンナイ株式会社 Cylindrical burner

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR447827A (en) * 1912-08-30 1913-01-16 Francis George Crone radiator and mixer element for fluids and gases
US1896286A (en) * 1929-01-23 1933-02-07 Burns Bruce Burner plate
FR1037897A (en) * 1951-05-30 1953-09-23 Utilisation Ration Gaz Method and devices for stabilizing the flames of premix burners
DE1543204A1 (en) * 1964-06-04 1970-07-16 Magyar Asvanyolaj Es Foeldgaz Process and incinerator for the production of unsaturated hydrocarbons from saturated hydrocarbons by means of thermal decomposition through flame reaction
NL6414634A (en) * 1964-12-16 1966-06-17
FR2373750A1 (en) * 1976-12-09 1978-07-07 Louyot Comptoir Lyon Alemand Fuel burner with multicellular structure - has spiral of expanded metal supported on parallel tubes in cylindrical container

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9416269A1 *

Also Published As

Publication number Publication date
DE69400373D1 (en) 1996-09-19
FR2700604A1 (en) 1994-07-22
FR2700604B1 (en) 1995-04-07
ES2091691T3 (en) 1996-11-01
EP0679239B1 (en) 1996-08-14
WO1994016269A1 (en) 1994-07-21
DE69400373T2 (en) 1997-03-27

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