EP0040148B1 - Burner torch with a device for the protection against flasback, backflow of gas and production of dangerous gaseous mixtures - Google Patents

Burner torch with a device for the protection against flasback, backflow of gas and production of dangerous gaseous mixtures Download PDF

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Publication number
EP0040148B1
EP0040148B1 EP81400738A EP81400738A EP0040148B1 EP 0040148 B1 EP0040148 B1 EP 0040148B1 EP 81400738 A EP81400738 A EP 81400738A EP 81400738 A EP81400738 A EP 81400738A EP 0040148 B1 EP0040148 B1 EP 0040148B1
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EP
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Prior art keywords
gas
torch
intake
combustible gas
valve
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EP81400738A
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German (de)
French (fr)
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EP0040148A1 (en
Inventor
Philippe Visage
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Cessione Francaise De Terotechnologie Ste
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Ets R DUBE SA
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Priority to AT81400738T priority Critical patent/ATE7424T1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23D—BURNERS
    • F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
    • F23D14/46—Details, e.g. noise reduction means
    • F23D14/72—Safety devices, e.g. operative in case of failure of gas supply
    • F23D14/82—Preventing flashback or blowback
    • F23D14/825—Preventing flashback or blowback using valves

Definitions

  • the present invention relates to the field of torches.
  • It more particularly relates to a new torch comprising a device for protection against interior ignitions, gas return and creation of dangerous gaseous mixtures in particular upstream of said torch.
  • the torches intended to produce a flame are supplied, on the one hand, by a combustible gas and, on the other hand, by an oxidizing gas.
  • the gases exit from a set of orifices called an injector or mixer; they then mix in a conduit called the mixing chamber.
  • the mixture thus formed ignites at the outlet of the lance disposed on the torch through an orifice called a nozzle or nozzle.
  • the safety device generally consists of a non-return valve and a flame smothering device. It is necessary to have two devices, each of them being arranged, on the one hand, on the fuel gas circuit and, on the other hand, on the oxidant gas circuit.
  • valve on the fuel or oxidant gas supply circuit can be the source of variations in gas flow rate incompatible with the low value of the operating pressure appropriate to the usual working conditions and requiring setting changes.
  • the valve itself and more particularly its position can constitute a potential factor of incidents or accidents by flashback.
  • the safety of its operation depends on the distance at which it is mounted relative to the torch, but also on the inclination given to it by the user during work.
  • the reliability of the valve may be compromised in the short term due to fouling or deterioration of the internal mechanism.
  • this document relates to an oxyacetylene lighting torch and not to a welding torch.
  • the device FR-A No. 527827 leaves a volume of such a size inside the torch or of the torch, that an explosion can undoubtedly occur inside it. of the blowtorch.
  • the desired goal that is to say safety for the operator, is therefore in no way achieved by such a device.
  • This statement of non-satisfaction does not come from the licensee, but from independent organizations such as the National Research and Safety Institute for the Prevention of Accidents at Work and Occupational Diseases (INRS), as well as several funds insurance and sickness, which unambiguously meant that it was necessary to find a device making it possible to reduce the unprotected interior volume of the torch under conditions such that accidents would either be eliminated or considerably reduced.
  • Patents FR-A Nos . 1336491, 1480261 and CH-A No. 472632 disclose the possibility of using sintered sintering pipes or similar devices as a flame smothering element.
  • porous filter cylinder is disposed inside a sealed outer casing and itself serves as a housing for a check valve intended to be enclosed therein.
  • a filter element is provided on each of the gas circuits.
  • the device according to FR-A No. 1336491 also leaves a large volume between the tip of the torch and the first selected elements (valve and sintered), volume more than sufficient for accidents occur by return of the oxidant gas in the fuel gas circuit.
  • the oxidizing and combustible gases are treated in a perfectly identical or symmetrical manner which, obviously, is not the case of the present invention where the structure of the torch and the means put in place confirm that these gases are not considered in the same way.
  • the flame arrestor device which consists of a pellet of metallic or ceramic porous material, tually obtained by sintering, is located as close as possible to the fusion nozzle through which the flame shoots out in the open air.
  • the sinter is located downstream of the mixing chamber since the gaseous mixture is not, of course, made at the outlet of the torch.
  • the CH-A patent? 472632 uses two and not a sinter, each of the devices being located on the gas inlet.
  • the object of the invention is precisely to provide a solution to the problem previously posed and relates to a new torch comprising a device for protection against interior ignitions and gas return.
  • the torch according to the invention comprises means for the admission of a combustible gas and means for the admission of an oxidizing gas, the pressure of this gas being greater than that of the combustible gas, means for adjusting the flow rate of these gases disposed on said intake means; means for mixing said gases; means for the outlet of said gas mixture to the nozzle or the nozzle of said torch and two non-return valves disposed respectively in each of the means for the admission of gas.
  • the torch is characterized in that the non-return valve which is arranged in the means for the admission of combustible gas is placed downstream of the corresponding adjustment means, and in that a means, such as a metallic sinter, for suffocating a flame is disposed in the means for admitting the combustible gas, between the non-return valve and the mixing means, in the immediate vicinity of the latter.
  • a means such as a metallic sinter
  • the non-return valve located in the means for admitting the combustible gas is preferably arranged in the means for adjusting the flow rate of this gas.
  • the means for smothering a flame is generally constituted by a metallic frit, that is to say by a porous cylinder of a sintered metal, therefore a stainless steel which acts as a molecular sieve to absorb the deflagration and smother the flame.
  • the means for adjusting the flow rate of oxidizing gas are constituted by a device called a grooved needle of the type described in the patents FR N os 592979, filed on April 18, 1924 in the name of R. Dube and P. Guerchin, and 609335, filed April 23, 1925.
  • this device makes it possible to use only a metallic sinter, unlike the two which were required previously, since in fact two devices were necessary, that is to say one per gas circuit.
  • the device according to the invention also has a much shorter reaction time than the gas or flame return phenomenon.
  • the device presently described makes it possible to avoid any return of the oxidizing gas in the fuel gas circuit.
  • the torch according to the invention is much less sensitive to the inclination to which it is subjected by its user, in course of use.
  • This torch 1 comprises a means for the admission 2 of a combustible gas and a means for the admission 3 of an oxidizing gas.
  • Devices for adjusting the flow rate 4 and 5 are disposed respectively on each of the intake means and allow the user to adjust the gas supply as a function of the aims pursued.
  • the pressure of the oxidizing gas is generally higher than the pressure of the combustible gas.
  • a vacuum is created which makes it possible to suck the combustible gas during normal operation.
  • the fuel gas / oxidizing gas gas mixture can in principle only exist downstream of the so-called venturi systems 12.
  • the mixture of the gas is therefore ensured at 6 and is evacuated by means 7 such as a lance towards the nozzle or nozzle 8 of the torch and the ignition is carried out.
  • the safety device according to the invention consists, on the one hand, of a non-return valve 9 arranged in the gas inlet means fuel 2 and preferably in the adjusting device 4.
  • a non-return valve 10 is placed in the intake means for the oxidizing gas 3.
  • a flame smothering device such as a frit 11 is located downstream of the non-return valve 9 substantially at the level of the gas mixing zone 6 slightly upstream with respect thereto.
  • the nozzle or the nozzle 8 of the torch can become blocked due to fortuitous circumstances, it results in a discharge of the oxidizing gas in the fuel gas line.
  • the non-return valve 9 is closed at rest and only opens under the combined action of the pressure of the fuel gas and the depression due to the suction created by the so-called venturi system. 12 caused by the flow of oxidant gas.
  • This device will therefore close if it is subjected to a back pressure due either to a discharge of the oxidizing gas, or to an explosion of the mixture in the lance of the torch.
  • the flame smothering or sintered element 11, placed downstream of the valve 9, will smother a possible flame, caused by an ignition of the lance mixture.
  • the action of the frit 11 exerts an influence on the valve 9 since the smothering of the possible flame accentuates the closing of said valve 9, thus preventing any risk of gas introduction.
  • oxidizer in the fuel gas circuit both during use of the torch and between two uses.
  • valve 10 disposed in the intake means for the oxidant gas avoids the possible access of the combustible gas in the line of the oxidant gas 3. This case, in fact, would be possible when the fuel gas taps and oxidizer are open, when the supply of combustible gas is open while the supply of oxidant gas is closed, and when the nozzle or nozzle of the torch is obstructed or partially obstructed.
  • the torches according to the invention can be of any type, such as in particular those used with the usual gases in this field, such as oxygen, acetylene, propane, tetrene or any other gas.
  • non-return valves can also be of the conventional type and will simply have to be adapted to the dimensions of the torches used.
  • valve 9 is closed at rest and does not s 'opens only under the combined action of the fuel gas pressure and the pressure due to the suction created by the venturi system 12 caused by the flow of oxidant gas.
  • the flow adjustment means 5 are constituted by a grooved needle device of the type described in the aforementioned patents FR Nos . 592979 and 609335, to which those skilled in the art can refer.
  • the device placed in the immediate vicinity of the valve 10 and downstream of it, also plays the role of flame smother in a manner substantially similar to the sinter 11 and makes it possible to avoid rare, but possible, return of combustible gas in the oxidant gas circuit (plugged torch, oxidizer gas supply closed, fuel gas supply and valve open).
  • Non-return devices such as frits will also be chosen from existing models. As a rule, stainless steel frits are used.
  • a device of the conventional type was tested with regard to the influence of the inclination of the torch on the flow rates.

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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)
  • Lighters Containing Fuel (AREA)
  • Feeding And Controlling Fuel (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

1. A blowtorch (1) comprising means (2) for the intake of a combustible gas and means (3) for the intake of a combustion gas, the pressure of this gas being greater than that of the combustible gas ; means (4, 5) for controlling the flow of these gases, arranged in the said means for intake ; means (6) for ensuring the mixing of the said gases ; means (7) for the outflow of the said gaseous mixture to the burner or nozzle (8) of the said blowtorch ; and two non-return valves (9, 10) arranged respectively in each of the means for the intake of gas, characterised in that the non-return valve (9) which is arranged in the means for the intake of the combustible gas is placed downstream of the corresponding means of control (4), and in that a means (11), such as a metallic sinter, for suppressing a flame, is arranged in the means for the intake of the combustible gas, between the non-return valve (9) and the means for mixing, in the immediate vicinity of the latter components.

Description

La présente invention concerne le domaine des chalumeaux.The present invention relates to the field of torches.

Elle a plus particulièrement pour objet un nouveau chalumeau comportant un dispositif de protection contre les allumages intérieurs, retour de gaz et création de mélanges gazeux dangereux en particulier en amont dudit chalumeau.It more particularly relates to a new torch comprising a device for protection against interior ignitions, gas return and creation of dangerous gaseous mixtures in particular upstream of said torch.

On rappellera tout d'abord que les chalumeaux destinés à produire une flamme sont alimentés, d'une part, par un gaz combustible et, d'autre part, par un gaz comburant. Les gaz sortent d'un ensemble d'orifices appelé injecteur ou mélangeur; ils se mélangent ensuite dans un conduit appelé chambre de mélange. Le mélange ainsi formé s'enflamme à la sortie de la lance disposée sur le chalumeau par un orifice appelé bec ou buse.It will be recalled first of all that the torches intended to produce a flame are supplied, on the one hand, by a combustible gas and, on the other hand, by an oxidizing gas. The gases exit from a set of orifices called an injector or mixer; they then mix in a conduit called the mixing chamber. The mixture thus formed ignites at the outlet of the lance disposed on the torch through an orifice called a nozzle or nozzle.

Or, on sait qu'il se produit fréquemment un allumage prématuré à l'intérieur de l'appareil, lorsque, pendant le fonctionnement de l'outil, des circonstances fortuites, telles qu'un échauffement de la buse, des projections de scories dans l'orifice de la buse ou d'autres événements analogues provoquent une rentrée de flamme ou un retour du mélange vers l'amont de l'appareil. Un autre danger essentiel est dû aux retours de gaz comburant dans le circuit de gaz combustible avec création d'un mélange gazeux dangereux.However, it is known that there is frequently a premature ignition inside the appliance, when, during the operation of the tool, fortuitous circumstances, such as heating of the nozzle, projections of slag in the orifice of the nozzle or other similar events cause a reentry of flame or a return of the mixture upstream of the device. Another essential danger is due to the return of oxidizing gas in the fuel gas circuit with the creation of a dangerous gas mixture.

Pour éviter de tels inconvénients, dont les conséquences peuvent être extrêmement graves, des dispositions réglementaires ont été prises, imposant la présence de dispositifs de sécurité interposés entre le chalumeau et la bouteille d'alimentation.To avoid such drawbacks, the consequences of which can be extremely serious, regulatory measures have been taken, imposing the presence of safety devices interposed between the torch and the supply bottle.

Le dispositif de sécurité est composé généralement d'un clapet antiretour et d'un dispositif étouffe-flamme. Il est nécessaire de disposer de deux dispositifs, chacun d'entre eux étant disposé, d'une part, sur le circuit du gaz combustible et, d'autre part, sur le circuit de gaz comburant.The safety device generally consists of a non-return valve and a flame smothering device. It is necessary to have two devices, each of them being arranged, on the one hand, on the fuel gas circuit and, on the other hand, on the oxidant gas circuit.

Ces dispositifs ou organes de sécurité ne sont toutefois pas dénués d'inconvénients.These safety devices or bodies are not without drawbacks, however.

En effet, la présence d'un clapet sur le circuit d'alimentation de gaz comburant ou combustible peut être à l'origine de variations de débit de gaz incompatibles avec la faible valeur de la pression d'utilisation appropriée aux conditions de travail usuelles et nécessitant des modifications de réglage.Indeed, the presence of a valve on the fuel or oxidant gas supply circuit can be the source of variations in gas flow rate incompatible with the low value of the operating pressure appropriate to the usual working conditions and requiring setting changes.

Le clapet lui-même et plus particulièrement sa position peuvent constituer un facteur potentiel d'incidents ou d'accidents par retour de flamme. La sécurité de son fonctionnement, même à l'état neuf, dépend de la distance à laquelle il est monté par rapport au chalumeau, mais aussi de l'inclinaison donnée à celui-ci par l'utilisateur au cours de travaux. En outre, en l'absence d'entretien, la fiabilité du clapet peut être compromise à brève échéance eu égard à l'encrassement ou a la détérioration du mécanisme interne.The valve itself and more particularly its position can constitute a potential factor of incidents or accidents by flashback. The safety of its operation, even in new condition, depends on the distance at which it is mounted relative to the torch, but also on the inclination given to it by the user during work. In addition, in the absence of maintenance, the reliability of the valve may be compromised in the short term due to fouling or deterioration of the internal mechanism.

On insistera plus particulièrement sur un défaut inhérent à de tels dispositifs, qui est dû au fait même qu'ils doivent être adjoints au circuit d'alimentation de gaz entre le détenteur et le chalumeau. En effet, de par cette disposition, ils ne peuvent donner une sécurité maximale puisqu'ils sont situés dans des points mécaniquement fragiles de l'ensemble, se situant à l'entrée du chalumeau. A ce niveau, les pièces de raccord ou tuyaux, bien entendu extrêmement fragiles, peuvent donner lieu à des accidents extrêmement graves pour l'utilisateur qui est situé à proximité immédiate ou au contact avec ces organes.Particular emphasis will be given to a defect inherent in such devices, which is due to the very fact that they must be added to the gas supply circuit between the holder and the torch. Indeed, by this arrangement, they can not give maximum security since they are located in mechanically fragile points of the assembly, being located at the entrance of the torch. At this level, the connecting pieces or pipes, of course extremely fragile, can give rise to extremely serious accidents for the user who is located in the immediate vicinity or in contact with these organs.

Parmi les systèmes de ce type, on peut citer celui décrit par FR-A No 527827.Among the systems of this type, mention may be made of that described by FR-A No. 527827.

Il convient de préciser que ce document est relatif à une torche d'éclairage à l'oxyacétylène et non pas à un chalumeau pour soudure.It should be noted that this document relates to an oxyacetylene lighting torch and not to a welding torch.

De façon plus explicite, on peut rappeler que le dispositif FR-A N° 527827 laisse subsister à l'intérieur du chalumeau ou de la torche un volume d'une telle importance, qu'une explosion peut indubitablement se produire à l'intérieur même du chalumeau. Le but recherché, c'est-à-dire la sécurité pour l'opérateur, n'est donc aucunement atteint par un tel dispositif. Cette affirmation de non-satisfaction n'émane pas de la titulaire, mais d'organismes indépendants tels que l'Institut national de recherche et de sécurité pour la prévention des accidents du travail et des maladies professionnelles (INRS), ainsi que plusieurs caisses d'assurance et de maladie, qui ont signifié sans ambiguité qu'il convenait de trouver un dispositif permettant de réduire le volume intérieur non protégé du chalumeau dans des conditions telles que les accidents seraient soit supprimés, soit considérablement réduits.More explicitly, it may be recalled that the device FR-A No. 527827 leaves a volume of such a size inside the torch or of the torch, that an explosion can undoubtedly occur inside it. of the blowtorch. The desired goal, that is to say safety for the operator, is therefore in no way achieved by such a device. This statement of non-satisfaction does not come from the licensee, but from independent organizations such as the National Research and Safety Institute for the Prevention of Accidents at Work and Occupational Diseases (INRS), as well as several funds insurance and sickness, which unambiguously meant that it was necessary to find a device making it possible to reduce the unprotected interior volume of the torch under conditions such that accidents would either be eliminated or considerably reduced.

Les brevets FR-A Nos 1336491, 1480261 et CH-A No 472632 divulguent la possibilité d'utiliser dans des chalumeaux ou dispositifs similaires des frittés à titre d'élément étouffe-flamme.Patents FR-A Nos . 1336491, 1480261 and CH-A No. 472632 disclose the possibility of using sintered sintering pipes or similar devices as a flame smothering element.

Cependant, dans le brevet Fr No 1336491, le cylindre filtrant poreux est disposé à l'intérieur d'une enveloppe extérieure étanche et sert lui-même de logement à une soupape de retenue prévue pour y être enserrée.However, in patent Fr No 1336491, the porous filter cylinder is disposed inside a sealed outer casing and itself serves as a housing for a check valve intended to be enclosed therein.

En outre, il est prévu un élément filtrant sur chacun des circuits de gaz.In addition, a filter element is provided on each of the gas circuits.

On peut aussi préciser que le dispositif décrit dans ce document serait absolument inutilisable avec les pressions des gaz dont il est fait usage dans le dispositif selon l'invention.It can also be specified that the device described in this document would be absolutely unusable with the gas pressures which are used in the device according to the invention.

En dernier lieu, on remarquera que le dispositif selon FR-A No 1336491 laisse également subsister un volume très important entre la pointe de la torche et les premiers éléments retenus (valve et fritté), volume plus que suffisant pour que des accidents se produisent par retour du gaz comburant dans le circuit des gaz combustibles.Finally, it is noted that the device according to FR-A No. 1336491 also leaves a large volume between the tip of the torch and the first selected elements (valve and sintered), volume more than sufficient for accidents occur by return of the oxidant gas in the fuel gas circuit.

D'ailleurs, dans ce document, les gaz comburants et combustibles sont traités de façon parfaitement identique ou symétrique ce qui, à l'évidence, n'est pas le cas de la présente invention où la structure du chalumeau et les moyens mis en place confirment bien que ces gaz ne sont pas considérés de la même manière.Moreover, in this document, the oxidizing and combustible gases are treated in a perfectly identical or symmetrical manner which, obviously, is not the case of the present invention where the structure of the torch and the means put in place confirm that these gases are not considered in the same way.

Dans le FR-A No 1480262, le dispositif antiretour de flamme qui est constitué par une pastille en matière poreuse métallique ou céramique, habituellement obtenu par frittage, est situé le plus près possible de la buse de fusion par où jaillit la flamme à l'air libre.In FR-A No 1480262, the flame arrestor device which consists of a pellet of metallic or ceramic porous material, tually obtained by sintering, is located as close as possible to the fusion nozzle through which the flame shoots out in the open air.

Cette mention signifie bien que le fritté se situe en aval de la chambre des mélanges puisque le mélange gazeux ne se fait pas, bien entendu, au niveau de la sortie du chalumeau.This mention means that the sinter is located downstream of the mixing chamber since the gaseous mixture is not, of course, made at the outlet of the torch.

Le brevet CH-A ? 472632 utilise deux et non pas un fritté, chacun des dispositifs étant situé sur l'arrivée des gaz.The CH-A patent? 472632 uses two and not a sinter, each of the devices being located on the gas inlet.

D'autre part, ce document ne donne aucune indication sur les possibilités d'une coopération et d'une synergie entre un fritté, un dispositif statique, et une valve ou clapet, dispositifs dynamiques.On the other hand, this document gives no indication of the possibilities of cooperation and synergy between a frit, a static device, and a valve or valve, dynamic devices.

Il existe donc un besoin qui a d'ailleurs été exprimé par l'Institut national de recherche et de sécurité pour la prévention des accidents du travail et des maladies professionnelles (1 N RS), ainsi que par plusieurs caisses d'assurance et de maladie, pour un dispositif de sécurité au chalumeau qui permettrait d'empêcher la création d'un mélange inflammable à l'intérieur de la'lance ou dans le corps du chalumeau, puisque seules ces pièces peuvent constituer, dans l'ensemble, des éléments mécaniquement résistants.There is therefore a need which has also been expressed by the National Research and Safety Institute for the Prevention of Accidents at Work and Occupational Diseases (1 N RS), as well as by several insurance and sickness funds , for a torch safety device which would prevent the creation of a flammable mixture inside the lance or in the body of the torch, since only these parts can constitute, overall, mechanically elements resistant.

L'invention a pour objet précisément d'apporter une solution au problème précédemment posé et a pour objet un nouveau chalumeau comportant un dispositif de protection contre les allumages intérieurs et retour de gaz.The object of the invention is precisely to provide a solution to the problem previously posed and relates to a new torch comprising a device for protection against interior ignitions and gas return.

Le chalumeau selon l'invention comprend des moyens pour l'admission d'un gaz combustible et des moyens pour l'admission d'un gaz comburant, la pression de ce gaz étant supérieure à celle du gaz combustible, des moyens de réglage du débit de ces gaz disposés sur lesdits moyens d'admission; des moyens pour assurer le mélange desdits gaz; des moyens pour la sortie dudit mélange gazeux jusqu'au bec ou à la buse dudit chalumeau et deux clapets antiretour disposés respectivement dans chacun des moyens pour l'admission de gaz. Le chalumeau est caractérisé en ce que le clapet antiretour qui est disposé dans le moyen pour l'admission du gaz combustible est placé en aval du moyen de réglage correspondant, et en ce qu'un moyen, tel qu'un fritté métallique, pour étouffer une flamme, est disposé dans le moyen pour l'admission du gaz combustible, entre le clapet antiretour et les moyens de mélange, au voisinage immédiat de ces derniers.The torch according to the invention comprises means for the admission of a combustible gas and means for the admission of an oxidizing gas, the pressure of this gas being greater than that of the combustible gas, means for adjusting the flow rate of these gases disposed on said intake means; means for mixing said gases; means for the outlet of said gas mixture to the nozzle or the nozzle of said torch and two non-return valves disposed respectively in each of the means for the admission of gas. The torch is characterized in that the non-return valve which is arranged in the means for the admission of combustible gas is placed downstream of the corresponding adjustment means, and in that a means, such as a metallic sinter, for suffocating a flame is disposed in the means for admitting the combustible gas, between the non-return valve and the mixing means, in the immediate vicinity of the latter.

Le clapet antiretour situé dans le moyen pour l'admission du gaz combustible est, de préférence, disposé dans les moyens de réglage du débit de ce gaz.The non-return valve located in the means for admitting the combustible gas is preferably arranged in the means for adjusting the flow rate of this gas.

Le moyen pour étouffer une flamme est généralement constitué par un fritté métallique, c'est-à-dire par un cylindre poreux d'un métal fritté, donc un acier inoxydable qui agit comme un tamis moléculaire pour absorber la déflagration et étouffer la flamme.The means for smothering a flame is generally constituted by a metallic frit, that is to say by a porous cylinder of a sintered metal, therefore a stainless steel which acts as a molecular sieve to absorb the deflagration and smother the flame.

Dans un mode préféré de réalisation de l'invention, les moyens de réglage du débit de gaz comburant sont constitués par un dispositif dit à aiguille cannelée du type de celui décrit dans les brevets FR Nos 592979, déposé le 18 avril 1924 au nom de R. Dube et P. Guerchin, et 609335, déposé le 23 avril 1925.In a preferred embodiment of the invention, the means for adjusting the flow rate of oxidizing gas are constituted by a device called a grooved needle of the type described in the patents FR N os 592979, filed on April 18, 1924 in the name of R. Dube and P. Guerchin, and 609335, filed April 23, 1925.

On concevra que de tels chalumeaux présentent de grands avantages sur les chalumeaux antérieurs auxquels devait être adjoint un dispositif de sécurité.It will be appreciated that such torches have great advantages over previous torches to which a safety device was to be added.

D'une part, s'il se produisait une inflammation ou une explosion dans le chalumeau, ce phénomène interviendrait dans un circuit mécaniquement résistant, et les risques d'accident pour les utilisateurs seraient réduits par rapport au dispositif de l'art antérieur, où les retours de flamme ou explosions s'effectuaient en amont du chalumeau, dans des éléments vulnérables.On the one hand, if an ignition or an explosion occurred in the torch, this phenomenon would occur in a mechanically resistant circuit, and the risk of accident for users would be reduced compared to the device of the prior art, where flashbacks or explosions were made upstream of the torch, in vulnerable elements.

En outre, ce dispositif permet de n'utiliser qu'un fritté métallique, contrairement aux deux qui étaient exigés antérieurement, puisqu'en fait deux dispositifs étaient nécessaires, c'est-à-dire un par circuit de gaz.In addition, this device makes it possible to use only a metallic sinter, unlike the two which were required previously, since in fact two devices were necessary, that is to say one per gas circuit.

De plus, dans le dispositif selon l'invention, il existe une sorte de synergie entre le fritté et les clapets disposés en amont, plus particulièrement le clapet du circuit de gaz combustible.In addition, in the device according to the invention, there is a kind of synergy between the frit and the valves arranged upstream, more particularly the valve of the fuel gas circuit.

Le même phénomène se produit entre l'aiguille cannelée précitée et le clapet du circuit de gaz comburant.The same phenomenon occurs between the aforementioned grooved needle and the valve of the oxidant gas circuit.

Le dispositif selon l'invention a, en outre, un temps de réaction beaucoup plus court que le phénomène de retour de gaz ou de flamme.The device according to the invention also has a much shorter reaction time than the gas or flame return phenomenon.

En outre, en position statique, le dispositif présentement décrit permet d'éviter tout retour du gaz comburant dans le circuit de gaz combustible.In addition, in the static position, the device presently described makes it possible to avoid any return of the oxidizing gas in the fuel gas circuit.

En dernier lieu, il convient également de remarquer que, contrairement à ce qui se passait pour le dispositif de l'art antérieur, le chalumeau selon l'invention est beaucoup moins sensible à l'inclinaison à laquelle il est soumis par son utilisateur, en cours d'usage.Finally, it should also be noted that, unlike what happened with the device of the prior art, the torch according to the invention is much less sensitive to the inclination to which it is subjected by its user, in course of use.

L'invention sera maintenant illustrée en référence au dessin annexé sur lequel la figure unique représente une vue en coupe d'un chalumeau selon l'invention.The invention will now be illustrated with reference to the accompanying drawing in which the single figure shows a sectional view of a torch according to the invention.

Ce chalumeau 1 comprend un moyen pour l'admission 2 d'un gaz combustible et un moyen pour l'admission 3 d'un gaz comburant.This torch 1 comprises a means for the admission 2 of a combustible gas and a means for the admission 3 of an oxidizing gas.

Des dispositifs de réglage du débit 4 et 5 sont disposés respectivement sur chacun des moyens d'admission et permettent à l'utilisateur de régler l'arrivée du gaz en fonction des buts poursuivis.Devices for adjusting the flow rate 4 and 5 are disposed respectively on each of the intake means and allow the user to adjust the gas supply as a function of the aims pursued.

La pression du gaz comburant est généralement supérieure à la pression du gaz combustible. Par un système dit de venturi 12, il se crée une dépression qui permet d'aspirer le gaz combustible en fonctionnement normal.The pressure of the oxidizing gas is generally higher than the pressure of the combustible gas. By a so-called venturi system 12, a vacuum is created which makes it possible to suck the combustible gas during normal operation.

De ce fait, le mélange gazeux gaz combustible/ gaz comburant ne peut en principe exister qu'en aval des systèmes dits de venturi 12.As a result, the fuel gas / oxidizing gas gas mixture can in principle only exist downstream of the so-called venturi systems 12.

Le mélange du gaz est donc assuré en 6 et est évacué par des moyens 7 tels qu'une lance vers le bec ou buse 8 du chalumeau et on procède à l'inflammation.The mixture of the gas is therefore ensured at 6 and is evacuated by means 7 such as a lance towards the nozzle or nozzle 8 of the torch and the ignition is carried out.

Le dispositif de sécurité selon l'invention est constitué, d'une part, d'un clapet antiretour 9 disposé dans le moyen d'admission pour le gaz combustible 2 et, de préférence, dans le dispositif de réglage 4.The safety device according to the invention consists, on the one hand, of a non-return valve 9 arranged in the gas inlet means fuel 2 and preferably in the adjusting device 4.

De la même façon, un clapet antiretour 10 est disposé dans le moyen d'admission pour le gaz comburant 3.In the same way, a non-return valve 10 is placed in the intake means for the oxidizing gas 3.

Un dispositif étouffe-flamme tel qu'un fritté 11 est situé en aval du clapet antiretour 9 sensiblement au niveau de la zone 6 de mélange des gaz légèrement en amont par rapport à celle-ci.A flame smothering device such as a frit 11 is located downstream of the non-return valve 9 substantially at the level of the gas mixing zone 6 slightly upstream with respect thereto.

Si l'on considère que le bec ou la buse 8 du chalumeau peuvent s'obstruer à cause de circonstances fortuites, il s'ensuit un refoulement du gaz comburant dans la canalisation du gaz combustible.If it is considered that the nozzle or the nozzle 8 of the torch can become blocked due to fortuitous circumstances, it results in a discharge of the oxidizing gas in the fuel gas line.

En l'absence du dispositif de sécurité et à l'apparition d'une flamme d'un point d'incandescence ou d'un point d'échauffement, le mélange ainsi constitué pourrait s'enflammer ou exploser.In the absence of the safety device and the appearance of a flame from an incandescent point or a heating point, the mixture thus formed could ignite or explode.

Dans le dispositif selon l'invention, le clapet antiretour 9 est fermé au repos et ne s'ouvre que sous l'action conjuguée de la pression du gaz -combustible et de la dépression due à l'aspiration créée par le système dit du venturi 12 causée par le débit du gaz comburant.In the device according to the invention, the non-return valve 9 is closed at rest and only opens under the combined action of the pressure of the fuel gas and the depression due to the suction created by the so-called venturi system. 12 caused by the flow of oxidant gas.

Ce dispositif se fermera donc s'il est soumis à une contre-pression due soit à un refoulement du gaz comburant, soit à une explosion du mélange dans la lance du chalumeau.This device will therefore close if it is subjected to a back pressure due either to a discharge of the oxidizing gas, or to an explosion of the mixture in the lance of the torch.

En outre, l'élément étouffe-flamme ou fritté 11, placé en aval du clapet 9, étouffera une flamme éventuelle, causée par un allumage du mélange de la lance.In addition, the flame smothering or sintered element 11, placed downstream of the valve 9, will smother a possible flame, caused by an ignition of the lance mixture.

D'ailleurs, ainsi qu'il a été précédemment exposé, l'action du fritté 11 exerce une influence sur le clapet 9 puisque l'étouffement de la flamme éventuelle accentue la fermeture dudit clapet 9, interdisant ainsi tout risque d'introduction du gaz comburant dans le circuit de gaz combustible, aussi bien en cours d'utilisation du chalumeau qu'entre deux utilisations.Moreover, as has been explained above, the action of the frit 11 exerts an influence on the valve 9 since the smothering of the possible flame accentuates the closing of said valve 9, thus preventing any risk of gas introduction. oxidizer in the fuel gas circuit, both during use of the torch and between two uses.

De la même façon, le clapet 10 disposé dans le moyen d'admission pour le gaz comburant évite l'accès éventuel du gaz combustible dans la canalisation du gaz comburant 3. Ce cas, en effet, serait possible lorsque les robinets de gaz combustible et comburant sont ouverts, lorsque l'alimentation en gaz combustible est ouverte alors que l'alimentation du gaz comburant est fermée, et lorsque le bec ou la buse du chalumeau est obstrué ou partiellement obstrué.In the same way, the valve 10 disposed in the intake means for the oxidant gas avoids the possible access of the combustible gas in the line of the oxidant gas 3. This case, in fact, would be possible when the fuel gas taps and oxidizer are open, when the supply of combustible gas is open while the supply of oxidant gas is closed, and when the nozzle or nozzle of the torch is obstructed or partially obstructed.

On notera en outre que, même si un retour de flamme ou une explosion se produisait dans le chalumeau selon l'invention, ce qui semble peu probable pour les raisons précédemment évoquées, un tel accident se produirait dans une zone mécaniquement résistante de l'appareil et, de ce fait, ses conséquences seraient ou négligeables ou atténuées pour l'utilisateur.It will also be noted that, even if a flashback or an explosion occurs in the torch according to the invention, which seems unlikely for the reasons mentioned above, such an accident would occur in a mechanically resistant area of the device and, as a result, its consequences would be either negligible or attenuated for the user.

Tel n'était pas le cas dans les dispositifs de l'art antérieur où les deux dispositifs de sécurité étaient disposés sur chacun des circuits d'alimentation du gaz, et cela en amont du chalumeau.This was not the case in the devices of the prior art where the two safety devices were arranged on each of the gas supply circuits, and that upstream of the torch.

De par ces dispositions, les éventuels retours de flamme ou explosions qui se produisaient, advenaient dans des pièces mécaniquement non résistantes, en particulier au niveau des tuyaux ou des raccords, et pouvaient, de ce fait, être extrêmement dommageables.By virtue of these provisions, the possible flashbacks or explosions which occur occur in mechanically non-resistant parts, in particular at the level of pipes or fittings, and could, therefore, be extremely damaging.

De plus, les dispositifs de l'art antérieur étaient extrêmement sensibles à l'inclinaison, ce qui n'est présentement pas le cas.In addition, the devices of the prior art were extremely sensitive to tilting, which is currently not the case.

Il va de soi que les chalumeaux selon l'invention peuvent être de tout type, tel que notamment ceux utilisés avec les gaz usuels dans ce domaine, tels que l'oxygène, l'acétylène, le propane, le tétrène ou tout autre gaz.It goes without saying that the torches according to the invention can be of any type, such as in particular those used with the usual gases in this field, such as oxygen, acetylene, propane, tetrene or any other gas.

En ce qui concerne les clapets antiretour utilisés, ils peuvent également être de type classique et devront simplement être adaptés aux dimensions des chalumeaux utilisés.As regards the non-return valves used, they can also be of the conventional type and will simply have to be adapted to the dimensions of the torches used.

De même, les tarages ou réglages de ces clapets sont de la compétence de l'homme de l'art et devront être établis conformément à ce qui a été précédemment indiqué pour que, par exemple, le clapet 9 soit fermé au repos et ne s'ouvre que sous l'action conjuguée de la pression du gaz combustible et de la pression due à l'aspiration créée par le système du venturi 12 causée par le débit de gaz comburant.Likewise, the calibrations or adjustments of these valves are within the competence of a person skilled in the art and must be established in accordance with what has been previously indicated so that, for example, the valve 9 is closed at rest and does not s 'opens only under the combined action of the fuel gas pressure and the pressure due to the suction created by the venturi system 12 caused by the flow of oxidant gas.

Dans un mode préféré de réalistion de l'invention, les moyens de réglage de débit 5 sont constitués par un dispositif à aiguille cannelée du type décrit dans les brevets FR Nos 592979 et 609335 précités, auxquels l'homme de l'art pourra se référer.In a preferred embodiment of the invention, the flow adjustment means 5 are constituted by a grooved needle device of the type described in the aforementioned patents FR Nos . 592979 and 609335, to which those skilled in the art can refer.

Le dispositif, placé à proximité immédiate du clapet 10 et en aval de celui-ci, joue également le rôle d'étouffe-flamme de façon sensiblement analogue au fritté 11 et permet d'éviter des retours rares, mais possibles, du gaz combustible dans le circuit de gaz comburant (chalumeau bouché, arrivée du gaz comburant fermée, arrivée et robinet du gaz combustible ouverts).The device, placed in the immediate vicinity of the valve 10 and downstream of it, also plays the role of flame smother in a manner substantially similar to the sinter 11 and makes it possible to avoid rare, but possible, return of combustible gas in the oxidant gas circuit (plugged torch, oxidizer gas supply closed, fuel gas supply and valve open).

Les dispositifs antiretour tels que les frittés seront également choisis parmi les modèles existants. En règle générale, on utilise des frittés en acier inoxydable.Non-return devices such as frits will also be chosen from existing models. As a rule, stainless steel frits are used.

L'exemple suivant est destiné à illustrer l'invention sans aucunement en limiter la portée.The following example is intended to illustrate the invention without in any way limiting its scope.

On a testé un dispositif de type classique pour ce qui concerne l'influence de l'inclinaison du chalumeau sur les débits.A device of the conventional type was tested with regard to the influence of the inclination of the torch on the flow rates.

Dans ce cas, la flamme variait d'intensité à l'oeil nu, et un réglage des débits en cours d'utilisation était nécessaire.In this case, the flame varied in intensity with the naked eye, and adjustment of the flow rates during use was necessary.

Tel n'était pas le cas du dispositif de l'invention, pour lequel aucune variation de la flamme n'était visible à l'oeil nu, quelle que soit l'inclinaison du chalumeau.This was not the case with the device of the invention, for which no variation in the flame was visible to the naked eye, whatever the inclination of the torch.

En outre, on a provoqué volontairement une dizaine de retours de gaz dans le présent chalumeau et on n'a constaté, au démontage, aucun encrassement intérieur.In addition, about ten gas returns were provoked voluntarily in the present torch and there was no disassembly inside during disassembly.

De tels avantages, combinés à une sécurité accrue de l'appareil, n'existaient pas dans les chalumeaux de l'art antérieur auxquels étaient associés des dispositifs antiretour externes.Such advantages, combined with increased safety of the device, did not exist in the prior art torches with which external check devices were associated.

A titre de modifications et variantes envisageables, on notera qu'il est possible de prévoir un filtre fritté en aval du clapet du circuit de gaz comburant, ainsi que, le cas échéant, une butée de clapet sur le circuit gaz combustible.As modifications and possible variants, it will be noted that it is possible to provide a sintered filter downstream of the valve of the oxidant gas circuit, as well as, if necessary, a valve stop on the fuel gas circuit.

Il va également de soi que l'invention s'applique à tous les chalumeaux et notamment aux chalumeaux coupeurs et aux chalumeaux coupeurs- soudeurs.It also goes without saying that the invention applies to all torches and in particular to cutting torches and cutting-welding torches.

Claims (3)

1. A blowtorch (1) comprising means (2) for the intake of a combustible gas and means (3) for the intake of a combustion gas, the pressure of this gas being greater than that of the combustible gas; means (4, 5) for controlling the flow of these gases, arranged in the said means for intake; means (6) for ensuring the mixing of the said gases; means (7) for the outflow of the said gaseous mixture to the burner or nozzle (8) of the said blowtorch; and two non-return valves (9, 10) arranged respectively in each of the means for the intake of gas, characterised in that the non-return valve (9) which is arranged in the means for the intake of the combustible gas is placed downstream of the corresponding means of control (4), and in that a means (11), such as a metallic sinter, for suppressing a flame, is arranged in the means for the intake of the combustible gas, between the non-return valve (9) and the means for mixing, in the immediate vicinity of the latter components.
2. A blowtorch according to Claim 1, characterised in that the said non-return valve (9) is arranged in the means for controlling the flow (4).
3. A blowtorch according to either of Claim 1 or 2, characterised in that the said means for controlling the flow (5) of the combustion gas consist of a device having a grooved needle.
EP81400738A 1980-05-08 1981-05-08 Burner torch with a device for the protection against flasback, backflow of gas and production of dangerous gaseous mixtures Expired EP0040148B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81400738T ATE7424T1 (en) 1980-05-08 1981-05-08 BURNER LANCE WITH DEVICE TO PROTECT AGAINST BACK-FLOW, GAS BACKFLOW AND FORMATION OF HAZARDOUS GAS MIXTURES.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8010326 1980-05-08
FR8010326A FR2482259B1 (en) 1980-05-08 1980-05-08 TORCH WITH PROTECTION AGAINST INDOOR IGNITIONS, GAS RETURN AND DANGEROUS GAS MIXTURE CREATIONS

Publications (2)

Publication Number Publication Date
EP0040148A1 EP0040148A1 (en) 1981-11-18
EP0040148B1 true EP0040148B1 (en) 1984-05-09

Family

ID=9241772

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81400738A Expired EP0040148B1 (en) 1980-05-08 1981-05-08 Burner torch with a device for the protection against flasback, backflow of gas and production of dangerous gaseous mixtures

Country Status (4)

Country Link
EP (1) EP0040148B1 (en)
AT (1) ATE7424T1 (en)
DE (1) DE3163468D1 (en)
FR (1) FR2482259B1 (en)

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR344531A (en) * 1904-07-02 1904-11-07 Paul Charles Dumesml Gas torch
FR527827A (en) * 1920-12-01 1921-10-31 Ernest Preston Prator Oxy-acetylene torch
FR592979A (en) * 1924-04-18 1925-08-13 Improvements with oxy-acetylene torches or the like
FR609335A (en) * 1925-04-23 1926-08-12 Improvements with oxyacetylene torches or the like
FR756283A (en) * 1932-07-13 1933-12-07 Linde Air Prod Co Welding torch improvements
US2611424A (en) * 1948-07-17 1952-09-23 Smith Welding Equipment Corp Pressure-operated antibackflow device for cutting torches
FR1336491A (en) * 1962-09-19 1963-08-30 Safety system for torches and autogenous welding devices
FR1453621A (en) * 1965-11-10 1966-06-03 Messer Griesheim Gmbh Injection torch, fitted with interchangeable inserts for welding or cutting
FR1480261A (en) * 1966-03-29 1967-05-12 Development of anti-backfire devices for autogenous welding and cutting installations and for metallization gun torches
CH472632A (en) * 1967-11-04 1969-05-15 Mueller Max Flame arrester in the oxygen and fuel gas supply lines of a welding or cutting torch
FR2235622A5 (en) * 1973-06-29 1975-01-24 Atlantique Chantiers Oxy-acetylene burner for flame cutting of metals - with spring-loaded non-return valve on oxygen injector

Also Published As

Publication number Publication date
DE3163468D1 (en) 1984-06-14
FR2482259A1 (en) 1981-11-13
EP0040148A1 (en) 1981-11-18
FR2482259B1 (en) 1986-11-21
ATE7424T1 (en) 1984-05-15

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