EP1640663A2 - Improved gas burner with only internal flame - Google Patents

Abstract

The burner has a peripheral chamber (13) extending around a central zone to communicate with an inlet which is radially relative to passageways that are opened into the central zone. The passageways allow a mixture to flow from the peripheral chamber towards the central zone. A deflector (5) extending into a part of the chamber is positioned such that it separates the chamber into lower sub chambers.

Description

The present invention relates to an improved internal only flame gas burner.

• un pot muni d'une arrivée de mélange à brûler, et
• un chapeau coiffant ledit pot,

ledit pot et ledit chapeau délimitant :

• une zone centrale de combustion dudit mélange à brûler, et
• une chambre périphérique s'étendant autour de ladite zone centrale et communiquant avec ladite arrivée,

ledit brûleur comprenant en outre :

• une pluralité de passages permettant la circulation dudit mélange de ladite chambre périphérique vers ladite zone centrale, et
• un déflecteur s'étendant dans au moins une partie de ladite chambre.

Patent Application FR 02 16401 discloses an internal flame gas burner of the type comprising:

• a pot provided with an arrival of a mixture to be burned, and
• a hat styling said pot,

said pot and said cap delimiting:

• a central combustion zone of said mixture to be burned, and
• a peripheral chamber extending around said central zone and communicating with said arrival,

said burner further comprising:

• a plurality of passages allowing the circulation of said mixture of said peripheral chamber to said central zone, and
• a deflector extending into at least a portion of said chamber.

Although it presents a number of undeniable advantages, this burner does not offer quite satisfactory.

Indeed, it has been found in use that the flame is not evenly distributed around the central zone (or "chimney"), and that it is quite unstable, that is to say that its flow fluctuates over time.

The present invention aims to improve this burner of the prior art so as to eliminate the aforementioned drawbacks.

• un pot muni d'une arrivée de mélange à brûler, et
• un chapeau coiffant ledit pot,

ledit pot et ledit chapeau délimitant :

• une zone centrale de combustion dudit mélange à brûler, et
• une chambre périphérique s'étendant autour de ladite zone centrale et communiquant avec ladite arrivée,

ledit brûleur comprenant en outre :

• une pluralité de passages permettant la circulation dudit mélange de ladite chambre périphérique vers ladite zone centrale, et
• un déflecteur s'étendant dans au moins une partie de ladite chambre, ce déflecteur étant disposé de manière à séparer ladite chambre en une sous-chambre inférieure située sensiblement dans le prolongement de ladite arrivée, et en une sous-chambre supérieure adjacente auxdits passages, et à ménager un passage avec la paroi radialement extérieure de ladite chambre périphérique.

This object is achieved with a solely internal flame gas burner, of the type comprising:

• a pot provided with an arrival of a mixture to be burned, and
• a hat styling said pot,

said pot and said cap delimiting:

• a central combustion zone of said mixture to be burned, and
• a peripheral chamber extending around said central zone and communicating with said arrival,

said burner further comprising:

• a plurality of passages allowing the circulation of said mixture of said peripheral chamber to said central zone, and
• a deflector extending into at least a portion of said chamber, said deflector being arranged to separate said chamber into a lower sub-chamber located substantially in the extension of said inlet, and into an upper sub-chamber adjacent to said passages, and providing a passageway with the radially outer wall of said peripheral chamber.

In this burner according to the invention, the mixture to be burnt arrives in the lower sub-chamber and fills it before escaping to the upper sub-chamber and then to the passages opening into the central zone ("chimney") of the burner.

The filling of the lower sub-chamber makes it possible to ensure a good distribution and good homogenization of the mixture to be burned around the central zone before this mixture enters this zone.

The fact that the passage between the lower and upper sub-chamber is situated against the outer wall of the peripheral chamber, that is to say that it is offset radially with respect to the passages opening into the central zone, makes it possible to avoid that the mixture to be burned directly reaches these passages, and thus contributes to the good distribution and good homogenization of this mixture.

In addition, the pre-filling of the lower sub-chamber with the mixture to be burned makes it possible to ensure the continuity of the flow of this mixture towards the upper sub-chamber and then towards the passages opening into the central zone, which ultimately allows obtain excellent combustion stability.

• ledit déflecteur s'étend sur tout le périmètre de ladite chambre périphérique,
• ladite zone centrale est circulaire, et ledit déflecteur est annulaire,
• ledit déflecteur est fixé sur un épaulement circulaire dudit pot,
• ladite arrivée débouche dans ladite chambre périphérique sous ledit déflecteur,
• ladite arrivée pénètre légèrement à l'intérieur de ladite chambre périphérique,
• la section de ladite chambre périphérique diminue lorsqu'on s'éloigne de ladite arrivée,
• ladite diminution provient d'une remontée du fond dudit pot au fur et à mesure que l'on s'éloigne de ladite arrivée,
• ladite diminution provient d'un décalage des axes des parois radialement intérieure et extérieure de ladite chambre périphérique,
• ledit chapeau comprend une jupe reliée à une couronne munie de fentes radiales,
• les parois radialement intérieure et extérieure de ladite couronne sont inscrites sur des cônes inversés dont les sommets sont respectivement au-dessus et au-dessous du brûleur,
• ledit brûleur comprend un carter amovible reposant sur ladite jupe par l'intermédiaire de supports.

According to other characteristics of the burner according to the invention:

• said deflector extends over the entire perimeter of said peripheral chamber,
• said central zone is circular, and said deflector is annular,
• said deflector is fixed on a circular shoulder of said pot,
• said inlet opens into said peripheral chamber under said deflector,
• said arrival penetrates slightly inside said peripheral chamber,
• the section of said peripheral chamber decreases as one moves away from said arrival,
• said decrease comes from a rise in the bottom of said pot as one moves away from said arrival,
• said decrease comes from an offset of the axes of the radially inner and outer walls of said peripheral chamber,
• said cap comprises a skirt connected to a ring provided with radial slots,
• the radially inner and outer walls of said ring are inscribed on inverted cones whose vertices are respectively above and below the burner,
• said burner comprises a removable housing resting on said skirt by means of supports.

• la figure 1 est une vue en perspective éclatée d'un brûleur selon l'invention,
• la figure 2 est une vue en perspective du pot de ce brûleur, et
• la figure 3 est une vue en coupe axiale de ce brûleur,
• la figure 4 est une vue en perspective éclatée d'un autre mode de réalisation du brûleur selon l'invention,
• la figure 5 est une vue en coupe axiale de cet autre brûleur,
• les figures 6 et 7 représentent des détails de la figure 5, et
• la figure 8 est une vue partielle en perspective d'un élément faisant partie du brûleur des figures 4 à 7.

Other features and advantages of the present invention will result from the following description and the accompanying drawings, in which:

• FIG. 1 is an exploded perspective view of a burner according to the invention,
• FIG. 2 is a perspective view of the pot of this burner, and
• FIG. 3 is a view in axial section of this burner,
• FIG. 4 is an exploded perspective view of another embodiment of the burner according to the invention,
• FIG. 5 is a view in axial section of this other burner,
• Figures 6 and 7 show details of Figure 5, and
• FIG. 8 is a partial perspective view of an element forming part of the burner of FIGS. 4 to 7.

Referring now to Figure 1 which shows that, according to a first embodiment of preferably domestic use, the gas burner according to the invention comprises a pot 1, a cap 3, an annular baffle 5 and a annular spacer plate 7.

The pot 1 and the cap 3 are shaped so that once assembled, they define a convergent-divergent pipe 9, or Venturi effect pipe.

In the example shown, the pot 1 and the cap 3 have a generally circular shape, with the exception of the zone defining the Venturi effect pipe 9.

This pot and this cap are further shaped so as to define, when they are assembled, on the one hand a central combustion zone 11, and on the other hand a peripheral chamber 13 extending around the central zone 11 and communicating with the Venturi effect pipe 9.

Note also that the pot 1 and the cap 3 each comprise a plurality of respective bosses 15a, 15b distributed around the central zone 11.

These bosses are arranged to take the annular spacer plate 7 sandwiched once the burner assembly, and thus define a plurality of passages 17 to establish a communication between the peripheral chamber 13 and the central zone 11 (see Figure 3 ).

According to possible variants and not shown, these passages 17 could be formed only in the pot 1, or only in the cap 3, or even in an intermediate piece that would be placed between this pot and this cap.

As can be seen in particular in FIG. 3, the annular baffle 5 extends inside the peripheral chamber 13 once the cap 3 is mounted on the pot 1.

In the example shown, this deflector has an L-shaped section whose branch is fixed to the radially inner wall 19 of the peripheral chamber 13, on the pot 1, and whose other branch is substantially parallel to the general plane of this pot .

This deflector 5 thus provides a passage 21 with the radially outer wall 23 of the peripheral chamber 13.

Preferably, the radial width of the passage 21 is substantially equal to half the radial width of the peripheral chamber 13.

As can thus be understood, the baffle 5 thus separates the peripheral chamber 13 into two sub-chambers, namely a lower sub-chamber 25 extending under this baffle, and an upper sub-chamber 27 extending above this deflector.

It will of course be understood that the terms "lower" and "upper" are understood in relation to the normal position of use of the burner, that is to say a position in which the pot 1 is at the bottom and the cap 3 is at the top.

As can be seen in particular in FIG. 3, the lower sub-chamber 25 communicates with the outlet 29 of the Venturi effect duct 9, and the upper sub-chamber 27 communicates with the passages 17.

In the example shown, the pot 1 and the cap 3 have a substantially circular shape, so that the deflector 5 has a substantially annular shape.

This example is in no way limiting, and one could envisage a deflector 5 of any shape, adapted to that of the pot 1 and the cap 3.

It is thus also possible to envisage another variant in which, instead of making full turn of the peripheral chamber 13, the deflector 5 would extend only over part of this chamber.

Another variant could also be envisaged in which the deflector 5 would extend from the radially inner wall 19 to the radially outer wall 23, and include a plurality of orifices allowing the communication between the lower sub-chamber 25 and the sub-chamber. superior 27.

Preferably, as shown, the inlet 29 opens into the peripheral chamber 13 under the deflector 5.

It can further be provided, as is also shown in Figure 3, that the bottom 31 of the pot 1 rises slightly as one moves away from the inlet 29, thus generating a reduction of the section of the lower sub-chamber 25 as one moves away from this arrival.

In the embodiment of Figures 4 to 8, preferably for professional use (communities, restaurants, etc ...), the hat 3 includes a skirt 33 which bears on the pot 1 and, under this skirt, a ring 35 provided with slots 17 over its entire periphery.

These slots define passages between the upper sub-chamber 27 and the chimney 11.

Preferably, as can be seen in FIG. 5, the radially inner and outer walls of the ring 35 are inscribed on inverted cones, the vertices of which are respectively above and below the burner.

Note also that on the skirt 33 are arranged three supports 37, arranged at 120 ° from each other.

On these supports 37 rests a housing 39, having in its center an orifice 41 of diameter substantially equal to that of the chimney 11, and at its periphery a folded portion 43 defining a peripheral passage 45 towards the crown 35.

On a circular shoulder 47 of the pot 1 is fixed (by matting or crimping or welding or with screws) a baffle 5, of annular shape, separating the lower sub-chamber 25 from the upper sub-chamber 27.

Figure 7 illustrates the particular case where the deflector 5 is fixed by matting on the shoulder 47, a matted lug 49 being visible in this figure.

It will be noted that, preferably, the convergent-divergent duct 9 penetrates slightly inside the lower sub-chamber 25.

It will also be noted that, preferably, the axes A and A 'of the inner and outer walls of the peripheral chamber 13, respectively, are slightly offset with respect to each other, so that in its portion that is diametrically opposite to the pipe 9, this chamber becomes radially narrower.

The mode of operation and the advantages of the gas burner according to the invention result directly from the foregoing description.

It is first of all in the case of the first embodiment (burner "domestic": Figures 1 to 3).

It is necessary to imagine that in operation, a gas injector is placed at the entrance of the Venturi effect pipe 9.

This conduct has the function of ensuring an intimate mixture of the gas leaving the injector with the surrounding air.

At the outlet 29 of this pipe, there is a combustible mixture of gas and surrounding air.

This mixture opens out completely under the baffle 5, and thus begins by filling the lower sub-chamber 25.

Once this filling is done, the mixture to burn borrows the passage 21 over the entire periphery of the pot 1, then passes through the upper sub-chamber 27 and the passages 17, thus finally opening into the central zone 11 where it ignites and burns , thus releasing the necessary heat.

As can be understood in the light of the foregoing, the role of the deflector 5 is to allow a good distribution of the mixture to be burned throughout the peripheral chamber 13 before this mixture reaches the passages 17.

In this way it is possible to obtain a good distribution of the flame around the central zone 11.

In addition, the prior filling of the lower sub-chamber 25 with the mixture to be burned makes it possible to ensure the continuity of the flow of this mixture towards the upper sub-chamber 27 and then to the passages 17, which makes it possible to obtain excellent combustion stability.

Note that the provision that the inlet 29 opens under the baffle 5 ensures that the entire mixture to be burned fill the lower sub-chamber 25 before migrating to the upper sub-chamber 27.

Note that the provision that the section of the peripheral chamber 13 decreases away from the inlet 29 can create a pressure drop between the part of this room located near the arrival 29 and the part of this room located opposite this arrival.

This makes it possible to rebalance the flow rates of the mixture to be burned in these two zones, and thus to optimize the distribution of this mixture throughout the chamber 13.

The operating principle of the burner according to the second embodiment ("professional" burner: FIGS. 4 to 8) is similar to that of the burner according to the first embodiment: the mixture to be burned arrives inside the sub-chamber lower 25, begins by filling it, then borrows the passage 21 over the entire periphery of the pot 1, then passes through the upper sub-chamber 27 and the passages 17, thus finally opening into the central zone 11 where it ignites and burns, releasing the necessary heat.

It will be noted that the offset of the axes A, A 'of the inner and outer walls of the peripheral chamber makes it possible to free space in the zone 49 (see FIG. 5) of the chimney 11 which is radially opposite to the conduct 9.

This free space facilitates the installation of a pilot light 51 (see Figure 4), an ignition electrode or any other flame monitoring device such as thermocouples.

In addition, the radial shrinkage of the peripheral chamber 13 resulting from this axial offset makes it possible to produce the same effect of pressure drop as in the previous embodiment.

The fact of mounting the deflector 5 on a circular shoulder of the pot 1 ensures a perfect centering of the baffle relative to the chimney 11, and ensures excellent stability of the deflector.

Fixing the deflector 5 on the pot 1 by matting is a particularly simple solution, three lugs 49 arranged substantially at 120 ° may be sufficient.

The fact that the pipe 9 partially enters the interior of the peripheral chamber 13 avoids flashback may occur especially when closing the gas valve.

Providing that the radially inner and outer walls of the ring 35 are inscribed on inverted cones, as can be seen in FIG. 5, makes it possible to increase the radial dimensions of the passages 17, in particular in their upper parts, and thus to promote the laminar flow of the mixture to be burned, especially when the burner operates at low speed.

The supports 37 disposed on the skirt 33 of the cap 3 make it possible to keep the casing 39 away from this cap, and thus to establish the peripheral passage 45 between the outside and the crown 35.

This peripheral passage allows an additional air supply to the flames that exit into the chimney 11 through the passages 17, and thus contributes to the good combustion of the mixture to be burned and, ultimately, to improve the energy efficiency of the burner.

The housing 39 is removable, and also protects the burner from projections and splashes.

In addition, if it is equipped with adequate devices, it can support pans above the burner.

Of course, the present invention is not limited to the embodiment described and shown, provided by way of illustrative and non-limiting example.

For example, it could be envisaged, in the event that the upper part of the pipe 9 would open into the chamber 13 at a height greater than that of the baffle 5, to provide a boss in this upper part of the pipe. , making it possible to direct the flow of mixture to be burned under the deflector 5.

Claims (12)

1. A gas burner to only internal flame, of the type comprising: a pot (1) provided with an inlet (29) for a mixture to be burned, and a hat (3) capping said pot (1), said pot (1) and said cap (3) delimiting: a central zone (11) of combustion of said mixture to be burned, and - a peripheral chamber (13) extending around said central zone (11) and communicating with said inlet (29), said burner further comprising: a plurality of passages (17) allowing said mixture of said peripheral chamber (13) to flow towards said central zone (11), and a deflector (5) extending in at least a portion of said chamber (13), said deflector (5) being arranged to separate said chamber (13) into a lower sub-chamber (25) located substantially in the extending said inlet (29), and an upper sub-chamber (27) adjacent said passages (17), and providing a passage (21) with the radially outer wall (23) of said peripheral chamber (13). 2. Burner according to claim 1, wherein said baffle (5) extends over the entire perimeter of said peripheral chamber (13). 3. Burner according to one of claims 1 or 2, wherein said central zone (11) is circular, and said deflector (5) is annular. 4. Burner according to any one of claims 1 to 3, wherein said baffle (5) is fixed on a circular shoulder (47) of said pot (1). 5. Burner according to any one of the preceding claims, wherein the radial width of said passage (21) is substantially equal to half the radial width of said peripheral chamber (13). 6. Burner according to any one of the preceding claims, wherein said inlet (29) opens into said peripheral chamber (13) under said baffle (5). 7. A burner according to any preceding claim, wherein said inlet (29) projects slightly inside said peripheral chamber (13) .8. Burner according to any one of the preceding claims, wherein the section of said peripheral chamber (13) decreases as one moves away from said inlet (29). 9. Burner according to claim 8, wherein said decrease comes from a rise of the bottom (31) of said pot (1) as one moves away from said inlet (29). 10. Burner according to claim 8, wherein said reduction is from a shift axes (A, A ') of the radially inner walls (19) and outer (23) of said peripheral chamber (13). 11. Burner according to any one of the preceding claims, wherein said cap comprises a skirt (33) connected to a ring (35) provided with radial slots (17). 12. Burner according to claim 11, wherein the radially inner and outer walls of said ring (35) are inscribed on inverted cones whose vertices are respectively above and below the burner. 13. Burner according to one of claims 11 or 12, comprising a removable housing (39) resting on said skirt (33) via supports (37).

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