FR2701540A1 - Combustion chamber with burner on face and system for reducing the emissions of pollutant bodies, such as oxides of nitrogen - Google Patents

Abstract

The present invention relates to a combustion chamber with burners on the front face. This chamber (1), of the type comprising a wall known as the front face (11) through which at least one feed burner (2) is arranged, is characterised in that at least one supplementary oxidant injection nozzle (301-309; 321-329) is provided in the chamber at a predetermined distance from the burner (2) following a fuel injection direction (L) and defining a supplementary fuel-injection plane delimiting two combustion zones, on the interior of each of which the quantity of oxidant supplied is at most slightly greater than the quantity necessary for stoichiometric combustion of the fuel, and in that the flame formed in this chamber (1) is propagated in a rectilinear manner upstream of a first supplementary injection plane (P1) and in a turbulent swirl downstream of this plane (P1). This combustion chamber (1) can be used in the production of boilers, ovens or the like which function with a liquid or pulverised soild fuel.

Description

 The present invention relates to a combustion chamber, for a boiler, a furnace or the like, and comprising a system which makes it possible to reduce the emissions of polluting bodies, such as, in particular, nitrogen oxides.

 It has already been proposed in the prior art to equip a boiler or an oven with a combustion chamber, inside which a mixture of fuel and oxidant is introduced at a wall of the chamber called "facade before ", in order to be burned. More specifically, at least one burner, that is to say a system combining a supply of oxidant under pressure and a fuel injector, is arranged, preferably in a quarl, on the front and oriented in a direction of injection approximately perpendicular thereto, so as to propagate said mixture inside the chamber.

 In addition, in the case where one or more burners open into the combustion chamber, mixtures of different compositions may be alternately burned. Then, each quarry is designed for one or more fuel and oxidant mixtures. For example, it is possible to choose as fuel a liquid or gaseous fluid, as well as a solid in powder form, while the oxidant can be inter alia air, often heated to a temperature that can be between 20 and 300 ° C and optionally enriched with oxygen, oxygen or recycled gases.

 However, the chambers of the type described above generate significant amounts of pollutants, including nitrogen oxides or "NOX", during the combustion of the mixture. This is mainly due firstly to the manner in which the propagation of this fuel mixture is carried out, and secondly to the composition of this mixture.

 Indeed, the propagation in the chamber of the fuel mixture by the known facade burners, is carried out turbulently, and in particular when it is sought to cause a flashback. The flame thus obtained is short (in the form of a "fireball"), dense and at a very high temperature.

However, it is known that the higher the combustion occurs at high temperature, the more it releases pollutants such as nitrogen oxides, and the longer the life of the parts of the burner in contact with such a flame decreases.

 Moreover, since the proportion of oxidant in the mixture propagated inside the chamber by each of the known facade burners is sufficient for all the fuel contained in this mixture to be burned, the latter contains a very large excess of oxidant. at the exit of the burner, that is to say in the flame front zone, so that at the other end of this flame (or tail), the combustion is carried out in an atmosphere slightly richer in oxidant than for stoichiometric combustion.

Therefore, the combustion is carried out mainly in an atmosphere that is excessively rich in oxidant, and thus conducive to the formation of NOX.

Also it has been proposed in the prior art to equip this type of combustion chambers, with special burners called burners "low NOX". These burners generally comprise a cooled quarry or refractory material such as concrete, steel or cement and several fuel injectors distributed in the plane of the facade, inside this quarl. Nevertheless, such low burners
NOX are relatively expensive to buy and maintain, and in the case of liquid fuel, consume significant amounts of water vapor.

 It has also been proposed in the prior art so-called "tangential heating" boilers. With such boilers it has been noticed that it is possible to obtain a combustion producing less oxides of nitrogen than with the front burner chambers. These tangentially heated boilers comprise a substantially prismatic chamber whose longitudinal edges are equipped with bars or "barges" where are distributed fuel injectors and oxidizer supply systems. The feed systems and injectors of these boilers are oriented approximately convergently towards a central axis parallel to the longitudinal barges.

A turbulence is thus obtained in the form of layers wound around the central axis of the chamber, and therefore perpendicular to the fuel injection direction. However, the barges, and therefore the central axis of the chamber, must be arranged vertically for this type of boiler works well, and what makes the latter is relatively bulky.

 Also, the present invention aims to provide a combustion chamber that overcomes the disadvantages of the prior art stated above.

 For this purpose, the subject of the invention is a combustion chamber for furnace, boiler or the like, and of the type comprising a so-called "front wall" wall through which is arranged at least one burner oriented in a direction of fuel injection. approximately perpendicular to said facade, and adapted to propagate or project inside the chamber a mixture of oxidant and any fuel to be burnt, characterized in that at least one additional oxidant injection nozzle is provided in the chamber at a predetermined distance from the burner in the direction of injection and preferably oriented in a plane approximately perpendicular thereto, each complementary injection plane delimiting two combustion zones inside each of which the amount of oxidant provided is substantially equal to or slightly greater than the amount required for stoichiometric combustion of the fuel in this zone, and in that, the burner propagating the mixture approximately rectilinear in the zone where it opens, the complementary oxidant injected into each zone downstream of an injection plane along the direction of propagation of the fuel , causes on the latter a turbulent spinning rotation and axis parallel to the direction of injection of the fuel.

 According to another feature, the combustion chamber is of prismatic shape, and comprises for each zone downstream of an injection plane at least two nozzles, each of which forms a jet of oxidant secant jet of another nozzle of the same area. At least one of these nozzles may be disposed near a longitudinal edge of the chamber substantially parallel to the aforementioned direction of injection.

 In the case of a chamber with a section in the form of a parallelogram or a quadrilateral, the ratio between the two sides of the parallelogram is preferably between 1 and 1.25.

 Advantageously, at least two oxidant injection nozzles, possibly arranged on either side of an injection plane and near the same longitudinal edge of the chamber, are fed by a common collector or rail. - even connected to a source of oxidizer under pressure.

 For example, the aforementioned collector may be provided with at least one butterfly valve or the like, adapted to regulate the oxidant flow of each nozzle disposed downstream of this valve. Similarly, at least one of the injection nozzles can be fed with oxidant via a control valve.

 According to yet another characteristic, the injection nozzles of at least one zone are oriented in a direction substantially tangent to the periphery of the flame in this zone and in the direction of the twist formed by this flame.

 It will be noted here that at least one feed burner has, at its outlet, one or more elements protruding into the oxidant flow of the burner, and acting as flame catchers.

 Furthermore, it is possible that one or more burners have at least two injectors which respectively allow to propagate in the chamber a different fuel.

 It can also be envisaged that, if at least one of the fuels burned in the chamber is a solid fuel, the aforementioned injection direction is approximately horizontal and that a wall of the chamber substantially parallel to this direction and which constitutes the bottom or sole of this chamber is in the form of recovery hopper or "ashtray", grid or fluidized bed.

 In addition, at least two breaking nozzles are arranged facing each other in a direction perpendicular to the direction of injection and secant to the axis of rotation of the fuel, in the injection zone furthest from the facade. forward according to the direction of propagation of the fuel.

But other features and advantages of the present invention will become more apparent from the detailed description of embodiments, given by way of example only, which follows and refers to the accompanying drawings, in which:
- Figure 1 is a schematic perspective view of a combustion chamber according to the invention;
- Figure 2 is a sectional view along an injection plane of the chamber of Figure 1, and perpendicular to the longitudinal direction thereof;
- Figure 3 is a longitudinal sectional view of a feed burner for a combustion chamber according to the invention; and
FIG. 4 is a diagram whose abscissa represents the longitudinal direction of a chamber according to the invention and whose ordinate indicates the cumulative quantity of oxidant supplied or injected.

 Referring to Figures 1 and 2, there is shown a combustion chamber 1, for example for a boiler, a furnace or the like. The longitudinal direction of the chamber 1 is designated L. The combustion chamber 1 comprises a wall 11 substantially perpendicular to the direction L, and called front facade.

 Although the longitudinal direction L of the combustion chamber 1 is approximately horizontal in Figures 1 to 3, it is possible that it is oriented in another arrangement in space, and for example in the vertical.

2 denotes in Figures 1 and 3 a burner, arranged on the facade 11 of the chamber 1 and for propagating inside thereof, a mixture of fuel and oxidizer. More specifically, the burner 2 is disposed coaxially in a well 21, for example of cylindrical shape, and which opens into the chamber 1. A primary oxidizer supply device 22 is provided in the opening 21 of the burner 2. This device 22 is connected and fed by a primary source P of oxidant under pressure, such as air, oxygen or a mixture of recycled gases, in particular. A fuel injection system 23 is also provided in the opening 21 of the burner 2 and connected to a fuel source F. The injection system 23 and the feed device 22 allow the burner 2 to propagate a mixture of fuel and oxidizer in the chamber 1, in a direction generally parallel to L and in the direction A of its distance from the facade 11. In fact, since the injection system 23 and the feeder 22 are oriented approximately close parallel to the direction
L, it is also called direction of injection of the oxidant.

 It goes without saying that several burners similar to that just described can be provided on the facade 11. In this case, we try as much as possible to group these burners relative to each other. Then, several different fuels, possibly mixed with respectively different oxidants, can be used in the combustion chamber 1. Among other things, it is possible to burn in the chamber 1 oil, gas, coal or pulverized waste, in the extent that at least one suitable burner is provided on the facade there. In addition, the chamber 1 comprises an exhaust E allowing the evacuation of gases and fumes produced during the combustion of the mixture.

 According to the invention, at least one additional oxidant injection nozzle is provided in the chamber 1 at a predetermined distance from the burner 2 in the feed direction L and is preferably oriented in a plane (P1 to P5) approximately perpendicular to it. Each complementary injection plane (coinciding with the plane of the sheet in FIG. 2) delimits two combustion zones inside each of which the quantity of oxidant supplied is substantially equal to or slightly greater than the quantity necessary for stoichiometric combustion. In addition, each burner 2 of the front facade 11 propagating said mixture approximately rectilinear in the zone where it opens, the complementary oxidant injected into each zone downstream of a subsequent injection plane. the direction A of propagation of the fuel, causes on the latter a setting in turbulent rotation in tendrils and axis parallel to the direction of injection L.

 It should be noted that the planes and the injection areas are described here only to allow a good understanding of the invention. Obviously, the interior of the chamber 1 constituting one and the same space where the fluids can circulate, the concept of zone is of course to interpret in the broad sense, that is to say by admitting certain fluid transfers through the injection plans.

 It is already understood that with the aid of the particular structure of the chamber 1 according to the invention, the oxidant distribution is carried out staggered or distributed in the longitudinal direction L, as is clear from FIG. 4. By such a staging, the flows flowing in the space defined by the chamber 15 are optimized, so that the combustion takes place under better conditions.

 To illustrate this, FIG. 4 is a diagram on which the abscissa corresponds to the longitudinal direction L of a chamber 1, from its front wall 11 to a wall 12 disposed opposite the facade and constituting the Another longitudinal end of the chamber 1. The ordinate of the diagram of FIG. 4 indicates the quantities Q of oxidant injected into the chamber 1, cumulative along L. This diagram shows a horizontal line EDT which indicates that all the oxidant necessary to burn the fuel propagated by a burner is injected at the level of the facade 11, into the combustion chambers of the prior art. The transverse line ST indicates cumulatively, the quantity of oxidant necessary to obtain a stoichiometric combustion of the fuel. injected at the level of burners 2 of a facade into a combustion chamber having a structure such as those just described. The comparison between the ST stoichiometry line and the EDT line, makes it perfectly clear that in the combustion chambers of the prior art, the fuel is burned in a very high oxidative atmosphere, and thus favorable to the production of NOX, especially near the burners.

 On the contrary, it emerges from the level line INV which represents the stepwise injection according to L, that in a combustion chamber 1 according to the invention, thanks to the complementary injection nozzles, the fuel injected at the level of the facade 11 is burned in a very slightly oxidizing excess atmosphere, compared with the ST line, so that the combustion chambers according to the invention generate an acceptable amount of NOX, especially in view of environmental legislation in force.

 Another essential difference between the invention and the prior art is that the propagation of the fuel mixture by each burner 2 is carried out in a slightly turbulent manner, that is to say in the form of a "flow" parallel". In other words, each burner 2 of the chamber 1 according to the invention is provided to propagate the mixture to be burned, almost without being rotated about an axis centered on this burner and parallel to L, and therefore substantially rectilinear. Nevertheless, it should be noted here that the thus propagated mixture expands perpendicularly to L due to the temperature and density variations caused by the combustion, which is why the flow illustrated in FIG. flaring in the direction of arrow A.

 However, it is known that a rectilinear or "laminar" propagation makes it possible to minimize the production of NOX and other pollutants, close to the front zone of a flame, that is to say at the exit of the burner . In fact, in this zone of the flame designated F in FIG. 3, it is the thinnest and fastest burning fuel particles that burn (gas, vapors, fine dust, etc.) and the combustion of this fuel. particle type generates relatively little NOX, if it is carried out within a "rectilinear flow" such as that produced by the burner 2 of the invention.

 In FIG. 4, the front zone of the flame F produced in the chamber 1 according to the invention is designated PA, and is called the rectilinear propagation zone of the fuel mixture.

 As has been explained above, the supply of the burner 2 by the fuel sources F and primary oxidant P is adjusted or adjusted so that the fine particles are burned inside the PA zone, and in a slightly more oxidative environment with respect to stoichiometric combustion, as is apparent from FIG. 4.

 On the other hand, it is known that by burning the fine and rapidly-ignited fuel particles, an atmosphere rich in carbon dioxide (CO2) is created around the remaining fuel particles, namely the particles of larger volume, carbon-rich fixed and therefore relatively difficult to ignite. In fact, downstream of the flame front along the direction of propagation A and the direction of injection L, a parallel or rectilinear flow of the fuel does not make it possible to obtain optimal combustion conditions. It is therefore interesting to increase downstream of the flame front, stirring between fuel and oxidant, for example by increasing the intensity of turbulence.

 For this purpose, the chamber 1 is equipped with complementary injection nozzles such as those designated by references 301 to 309 and 321 to 329 in Figure 1. It is well understood that to preserve the benefits of particle combustion fuel fines in a "rectilinear" injection flow, the nozzle or nozzles closest to the facade 1 1 (here the nozzles arranged in the same plane P1 as those designated in 301 and 321) must be arranged at a distance of predetermined distance from the outlet of the burner 2.This distance, which is equal to the length of the zone PA (FIG. 4), corresponds to a position along L where a complementary injection of oxidant capable of causing a turbulent spinning of the flame F, allows combustion generating fewer pollutants such as NOX, if the supply was always performed in the form of a rectilinear flow.

 It is obvious that for the efficiency of such a complementary injection to be optimal, the position of the front of the flame F relative to the outlet of the burner 2 must be stable. For this purpose, it is advantageous to provide at the outlet of each burner 2 of the facade 11, which is common to call "catchy flame". According to the example of FIG. 3, the flame catcher of the burner 2 is constituted by one or more elements 24 projecting into a primary oxidant flow IP so as to generate one or more vortices V. These vortices V are away from the IP flow, permanently cause the rotation of a secondary flame ensuring a fixed position of the front of the main flame F.

 It can be seen from the example of FIGS. 1 and 2 that the combustion chamber 1 is of prismatic shape with a quadrilateral or parallelogram-shaped section, perpendicular to the direction L. Preferably, the ratio between the side or width D and the other side or height H of this section, and therefore of the facade 11, is between 1 and 1.25 so that the injection of additional oxidant is effected under optimum conditions. In other words, D <H <1.25 D.

 Furthermore, FIGS. 1 and 2 show that the chamber 1 comprises, for each zone downstream of the first injection plane P1 (the closest to the facade 1 1 along the direction A of fuel propagation), at least two nozzles (301, 321) each of which forms a jet of secant oxidizer or jet from another nozzle of the same zone. Here, at least one of these nozzles is disposed near a longitudinal edge of the chamber 1, and therefore an edge substantially parallel to the injection direction L.

 In fact, as can be seen in FIG. 2, the chamber 1 comprises, for each complementary injection plane, four injection nozzles in the form of oxidant.

However, it will be noted here that it may be particularly advantageous to provide three secant jet nozzles by complementary injection plane. Each of these injection nozzles protrudes inside the chamber 1, and is oriented in a direction substantially tangent to the periphery of the flame F at the injection plane to which it belongs, and in the direction of the spin (indicated by the arrows F in Figure 2) formed by this flame. Then, since each nozzle injects, as indicated by the arrows IC, the oxidant to the flame F, this oxidizer mixes with the fuel propagated along L by the burner 2, and gives the flame downstream of the corresponding injection plane , the shape of a spin or "corkscrew". Obviously, the sum of the injections IC of oxidant is determined to correspond to a contribution at most slightly higher than that required for a stoichiometric combustion of the fuel burned inside the corresponding area. In other words, the oxidant provided by the four injectors arranged between two injection planes, allows the particles burning between these planes, to be consumed in a slightly excess atmosphere oxidizer, as is clear from Figure 4.

 Still referring to FIGS. 1 and 2, it can be seen that it may be advantageous for at least two oxidizer nozzles, possibly arranged on either side of an injection plane (P1 to P5) and in the vicinity of the same longitudinal edge of the chamber 1, are fed by a collector or common rail (30 to 33), itself connected to a complementary source S of oxidizer under pressure (or at the source P). According to the illustrated example, all the injection nozzles located near the same edge parallel to L of the chamber 1 are connected to a common ramp 30, 31, 32 or 33. Thus, the nozzles 301 and 309 are connected. at a ramp 30 substantially parallel to L, and the nozzles 321 to 329 are fed by a ramp 32, also parallel to L.

 To adjust the amount of oxidant injected between two planes, it may be advantageous to provide one or more valves for regulating the flow rate of the oxidizer, between at least one nozzle and the source S. In FIG. 1, a butterfly valve or analogs 43 between the source S and the ramps 30 to 33, as well as butterfly valves 430 and 432 directly on the ducts respectively connecting the nozzles 309 and 329 to the manifolds 30 and 32. It is also conceivable that the collectors have a tapered shape the direction of circulation of the oxidant in these, andZ or one or more control valves are installed in these collectors.

 It goes without saying that the distance, perpendicular to the direction L, of which each injection nozzle described above projects inside the chamber 1 is determined so as to obtain the most efficient oxidant injection, without, however, exposing this nozzle unacceptably.

 In the same vein, that is to say to eliminate as much as possible the weathering of the elements of the chamber 1 according to the invention, it is conceivable that at least one of the burners 2 of the chamber 1 comprises at the level of the opening 21, an outlet horn of refractory material and such as cement, concrete, steel or the like, and / or cooled by circulation of a fluid in appropriate internal pipes. Thus, the aperture 21 shown in FIG. 3 comprises a conical shaped outlet bell 25 flaring in the direction of the arrow A and the direction L. Such a horn 25 also allows "to hang" the flame F at the exit of the quarney 21. It is also conceivable that this flag 25 is of cylindrical or polygonal shape, and that it is constituted or coated with a ceramic-based material or the like.

 In addition, if at least one of the fuels burned in the chamber 1 is a solid fuel such as coal for example or pulverized waste, it is advantageous to provide that the aforementioned supply direction L is approximately horizontal. In this case, the wall designated at 13 in Figures 1 and 2 is the bottom or bottom of the chamber I, may be formed by a hopper called "ashtray" or a grid. Then, this hopper or grate allows the recovery of the combustion residues or ashes generated in the chamber 1, and possibly allows a complementary supply of oxidant, inside the chamber 1. It is also possible that the sole 13 of a chamber 1 for solid fuels, forms what is usually called a "fluidized bed".

Now, the general operation of the chamber 1 according to the invention will be briefly explained, with reference to the figures. After having ignited in a conventional manner, a predetermined mixture of a fuel and an oxidant is propagated in the chamber 1, by all the burners arranged on the facade 1 1 and provided for this mixture. The primary injection IP (FIG. 3) in oxidant carried out by the burner (s) 2 is calculated to obtain a substantially stoichiometric combustion or very slightly exceeding in combustion, in particular near the first injection plane P1, namely at the end of the zone PA along the direction of advance A of the flame F. At this plane Pi, a first complementary injection IC of oxidant is carried out inside the chamber 1. As explained above, this complementary injection IC gives the flame F the form of swirls. It is understood that the flame F has a twist shape from the plane P1 closest to the facade 11 to its tail. As the fuel propagates along A in chamber 1, a stepwise supply of oxidant is performed at each complementary injection plane. In FIG. 4, the dotted lines represent complementary injection plans P1 to
P5, while following the example of Figure 1, nine series of four injectors roughly converging and connected to the ramps 30 to 33, form nine injection planes inside the chamber 1.In other words, the chamber illustrated in FIG. 1 comprises ten zones, one of which is located downstream of the plane P1 along the direction of A and which corresponds to the zone PA of FIG. 4. The other nine zones corresponding to them to the five zones comprised between the P1 plane and the wall 12. In the diagram of Figure 4, these areas are grouped within the same sector PT, where the propagation is carried out turbulently.

 Obviously, downstream following A of the last injection plane of a combustion chamber, all of the oxidant propagated by the or the openers 2 must be burned.

At this point, two "breaking" nozzles 50 and 52, similar to the complementary nozzles, and arranged facing each other in a direction perpendicular to L and secant to the axis of rotation of the flame F can be provided to stop or it will be noted here that, advantageously, these breaking nozzles 50 and 52 are not connected to the source S via a control valve, but directly
It will be understood that, thanks to the two sectors PA and PT and to the particular structure of the invention which has just been described, the chamber 1 makes it possible to obtain optimum conditions of combustion. With these conditions, the quantities of pollutants generated by the flame F, and in particular the nitrogen oxides, can be minimized. It goes without saying that the invention is not limited to the embodiments shown, but includes all the equivalents and combinations of technical means described, if they are carried out according to his spirit.

 Thus, the spacing between the different complementary injection planes along the longitudinal direction of the chamber may vary from one zone to another. Similarly, the complementary injection nozzles can be oriented at a slight angle, relative to a plane perpendicular to the direction of supply. It is understood that the maintenance of the combustion chamber 1 according to the invention is particularly easy, since all the fuel supply devices are located at the front panel 11, and the additional injection nozzles do not require considerable maintenance.

 The type of combustion chamber which has just been described applies for example to a natural circulation boiler, such as a two-balloon boiler, a forced circulation boiler, with or without a desulphurization or denitration system, or still post-combustion boilers, with cooled exhaust, and / or including injection devices * urgent, ammonia or lime. Moreover, this type of combustion chamber can without any problem adapt to an oven, an incineration system or the like.

Claims (12)

 Combustion chamber (1) for a boiler, oven or the like, and of the type comprising a wall (11) called "front panel" through which is arranged at least one burner (2) oriented in a direction of injection (L ) approximately perpendicular to said facade (11), and able to propagate or project inside the chamber (1) a mixture of oxidant and any fuel to be burnt, characterized in that at least one nozzle of complementary injection (301-309; 321-329) of oxidant is provided in the chamber (1) at a predetermined distance from the burner (2) in the direction of injection (L) of the fuel and oriented in a plane (P1- P5) approximately perpendicular to this direction, each complementary injection plane (P1-P5) delimiting two combustion zones inside each of which the quantity of oxidant supplied is substantially equal to the quantity necessary for a stoichiometric combustion of the fuel in this zone, and in that, the burner (2) propagating the mixture approximately rectilinear in the zone where it opens, the complementary injected oxidant (IC) in each zone downstream of an injection plane ( P1-P5) according to the direction of propagation (A) of the fuel, causes on the latter a turbulent spinning rotation and axis parallel to the injection direction (L).  2. Chamber according to claim 1, characterized in that it has a prismatic shape, and comprises for each zone downstream of an injection plane (P1-P5) at least two (301-309; 321-329) nozzles each of which forms a stream of jet fuel from the jet coming from another nozzle of the same zone.  3. Chamber according to claim 1 or 2, characterized in that at least one nozzle is disposed near a longitudinal edge of the chamber (1), substantially parallel to the injection direction (L) above.  4. Chamber according to claim 2 or 3, characterized in that the chamber having a section in the form of a parallelogram, the ratio (H / D) between one side (D) and the other side (H) of this parallelogram is included between 1 and 1.25.  Chamber according to one of Claims 1 to 4, characterized in that at least two oxidant injection nozzles (301-309; 321-329) are fed by a common collector (30, 31, 32, 33). ), itself connected to a source (S) of oxidizer under pressure.  6. Chamber according to claim 5, characterized in that the aforesaid collector (30, 31, 32, 33) comprises at least one valve adapted to regulate the oxidant flow of each nozzle disposed downstream of this valve.  7. Chamber according to one of claims 1 to 6, characterized in that at least one of the injection nozzles is supplied with oxidant via a control valve (43).  8. Chamber according to one of claims 2 to 7, characterized in that the injection nozzles (301-309; 321-329) of at least one zone, are oriented in a direction substantially tangent to the periphery of the flame (F) in this zone, and according to the direction of the twist formed by this flame.  9. Chamber according to one of claims 1 to 8, characterized in that at least one burner (2) comprises, at its outlet, at least one projecting element (24) in an oxidant flow of the burner (2), and acting as flame catchers.  10. Chamber according to one of claims 1 to 9, characterized in that one or more burners comprise at least two injectors (2) which respectively allow to propagate in the chamber a different fuel from that of the other injector.  11. Chamber according to one of claims 1 to 10, wherein at least one of the fuels that can be burned is a solid fuel, characterized in that the direction of injection (L) above is shortly near horizontal and that a wall of the chamber (1) substantially parallel to this direction (F) and which constitutes the bottom or sole (13) of this chamber, is in the form of recovery hopper called "ashtray", grid or fluidized bed.  12. Chamber according to one of claims 1 to 11, characterized in that at least two nozzles (50, 52) are arranged vis-a-vis in a direction perpendicular to the direction of injection (L) and secant to the axis of rotation of the flame (F), for braking or stopping the rotation thereof in the injection zone situated downstream of the plane of the complementary nozzles furthest from the front facade (11), according to the direction of propagation (A) of the fuel.