EP0866268A1 - Method of operating a vortex stabilised burner and burner applying the method - Google Patents

Abstract

To operate a twist-stabilised burner using a gas or liquid fuel, and especially as a premix burner, lighting-up air (38) is injected during the lighting-up process, at the downstream end of the twist generator (37) from the edge to the centre. The injected air has at least one radial speed component. After lighting-up, the injected lighting-up air stream (38) is stopped. The burner may have at least two units (40) at the downstream end of the twist generator (37), for at least a partially radial injection of lighting-up air (38) against each other. They are connected to feed lines (41), which can be closed selectively.

Description

Technical field

The invention relates to the field of combustion technology. It affects a method for operating a with gaseous and / or liquid fuels operated spin-stabilized burner and a suitable burner, in particular Premix burner.

State of the art

Swirl-stabilized burners are known. A swirl generator with a supercritical one With this type of burner, Swirl ensures intensive mixing of fuel and combustion air. The flame stabilization is based on the generation of a Backflow bubble, also called backflow zone, which is caused by the bursting of the Vortex (vortex breakdown) arises. Before the stagnation point of this backflow zone ignition of the flame is initiated and a stable flame front is formed.

An example of such swirl stabilized burners is the double cone type burner, the basic structure of which is described in EP 0 321 809 B1. This Premix burner consists essentially of at least two hollow to each other a complementary partial cone body with tangential air inlet slots and feeds for gaseous and liquid fuels in which the central axes the hollow partial cone body has a conical inclination widening in the direction of flow have and offset in the longitudinal direction to each other. Im from the conical interior of the conical bodies is on the burner head placed a fuel nozzle. The gaseous fuel becomes the combustion air flow in advance of its inflow into the interior of the burner arranged gas injectors supplied to the inlet slots. The formation of the Fuel / air mixture thus occurs directly at the end of the tangential one Air inlet slots.

The increase in the twist along the cone axis associated with the sudden Cross-sectional expansion at the burner outlet leads to the fact that downstream of the A return flow zone on the burner axis (inner recirculation zone) forms, which stabilizes the flame. Before the stagnation point of this inner Backflow zone, the ignition of the flame is initiated. It will be one if possible aimed for a short backflow zone.

With an unfavorable design of these burners, however, the central backflow area spreads on the cone axis far downstream into the combustion chamber. It arises a long, almost cylindrical backflow zone, the backflow Flue gases in the core extract the heat. At the start of the burner this will at the stagnation point in front of the backflow zone where the flame stabilizes, only cold medium transported back. This has the disadvantage that the Ignition of the fuel / air mixture is difficult or even prevented. In addition, the flame stabilization is weakened and the pollutant emissions, especially carbon monoxide and unburned hydrocarbons Burner start increased.

These disadvantages can also apply to burners with passive flue gas recirculation by injector delivery, which are described for example in EP 0 436 113 B1, occur. There is in addition to the normal combustion air during the starting process Air is injected into the burner head near the injectors. This With the currently implemented applications, the environment of the Burner head is flushed with the cold starting air and the return of hot Flue gas from the combustion chamber is obstructed. Heating up the system is very slow.

This also makes the ignition of the fuel / air mixture difficult, flame stabilization weakened and pollutant emissions increased.

Presentation of the invention

The invention tries to avoid all these disadvantages. It is based on the task to develop a method for operating a spin-stabilized burner, that enables ignition easily during the start-up phase of the burner, and high flame stabilization and low pollutant emissions leads. The normal operation of the burner should not be affected. Furthermore, a burner, especially a premix burner, is to be used of this method.

According to the invention, this is the case with a method according to the preamble of the patent claim 1 achieved in that during the starting process on the downstream End of the swirl generator directed from the edge of the burner into the center Starting air is injected, which is at least a radial speed component and that after the end of the starting process the injection the additional air is switched off. According to the invention, this is in one swirl-stabilized burner for performing the method achieved on downstream end of the swirl generator at least two means for at least partially radial injection of starting air are arranged, which with optionally lockable supply lines are connected.

The advantages of the invention include the fact that favorable ignition conditions be created, the flame stabilization is improved and the Pollutant emissions when starting the burner can be reduced. There are zones high shear and turbulence between the injected starting air jets and the swirled main flow, which intensify the mass transport. The central backflow bubble is pinched off and an intense fireball is created in the immediate vicinity of the burner. Most of the cold starting air arrives through the reaction zone into the hot vortex breakdown zone and transported Simultaneously fuel into the center and then towards the swirl generator. As a result, both mass flows immediately take part in the reaction and heat up strongly before the flame stabilization point is reached. A Flushing the environment with cold medium, as described in the prior art, is prevented in this way.

It is particularly useful if the starting air is purely radial and therefore not swirled is injected into the main flow.

But it is also advantageous if the starting air is radial / axial or radial / tangential is injected so that it is next to the radial speed component also has an axial and / or tangential speed component. A counter-swirl component of the starting air compared to the main flow is particularly important because it makes the zones particularly high Shear and turbulence generated between the start air flow and the main flow will.

Advantageous configurations of swirl-stabilized burners for implementation of the method according to the invention are described in the subclaims.

Brief description of the drawing

Several exemplary embodiments of the invention are shown in the drawing.

Fig. 1

einen Vormischbrenner der Doppelkegelbauart nach dem bekannten Stand der Technik in perspektivischer Darstellung;

Fig. 2

eine weitere perspektivische Darstellung dieses Vormischbrenners aus einer anderen Ansicht in vereinfachter Form;

Fig. 3

einen Schnitt durch den Vormischbrenner gemäss Fig. 1 oder 2, wobei der Brenner mit Injektoren bestückt ist und die Einströmungsebene von Zuführungskanälen parallel zur Brennerachse verläuft;

Fig. 4

eine Konfiguration des Injektorsystems in Strömungsrichtung;

Fig. 6

eine weitere Konfiguration des Injektorsystems in Strömungsrichtung;

Fig. 7

einen schematische Längsschnitt des erfindungsgemässen Vormischbrenners in einer ersten Ausführungsvariante;

Fig. 8

eine Vorderansicht des Brenners gemäss Fig. 7;

Fig. 9

einen schematischen Längsschnitt des erfindungsgemässen Vormischbrenners in einer zweiten Ausführungsvariante;

Fig. 10

eine Vorderansicht des Brenners gemäss Fig. 9.

Show it:

Fig. 1

a premix burner of the double cone type according to the known prior art in a perspective view;

Fig. 2

another perspective view of this premix burner from another view in a simplified form;

Fig. 3

a section through the premix burner according to Figure 1 or 2, wherein the burner is equipped with injectors and the inflow plane of supply channels runs parallel to the burner axis.

Fig. 4

a configuration of the injector system in the flow direction;

Fig. 6

a further configuration of the injector system in the flow direction;

Fig. 7

a schematic longitudinal section of the premix burner according to the invention in a first embodiment;

Fig. 8

a front view of the burner according to FIG. 7;

Fig. 9

a schematic longitudinal section of the premix burner according to the invention in a second embodiment;

Fig. 10

9 shows a front view of the burner according to FIG. 9.

Only the elements essential for understanding the invention are shown. The direction of flow of the media is indicated by arrows.

Way of carrying out the invention

The invention is explained below using exemplary embodiments and FIG. 1 to 10 explained in more detail.

The invention relates to the operation of swirl-stabilized burners. Examples of swirl-stabilized premix burners known from the prior art 1 to 6, which are described below. Such burners are operated with gaseous and / or liquid fuels within the burner intensively with combustion air or by a swirl generator a mixture of combustion air and recirculated flue gases and then burned. These burners are designed so that a Supercritical swirl number arises, so that the vortex of the fuel / air mixture burst open and form a backflow zone that stabilizes the flame.

The method according to the invention now consists in that during the starting process at the downstream end of the swirl generator from the edge of the burner air, so-called start air, is injected into the center. This Starting air must have at least one radial speed component, however, it can also have an axial and / or a tangential speed component exhibit.

Most of the cold starting air enters the hot air through the reaction zone Vortex breadown zone and simultaneously transports fuel to the center and then in the direction of the swirl generator. As a result, both mass flows immediately participate in the reaction and heat up strongly before the flame stabilization point is achieved. Rinsing the environment with cold medium is prevented. In addition, zones of high shear and turbulence generated between the injected starting air and the swirled main flow, which additionally intensify the mass transport and the flame stabilization improve. The central backflow bubble is pinched off and becomes more intense Fireball is created in the immediate vicinity of the burner. Through these phenomena favorable ignition conditions are created and flame stabilization is improved and reduced the starting emissions. If the starting air with a counter-swirl to the twisted main flow (fuel / air mixture) are the the above-mentioned effects are particularly pronounced.

When the start-up phase of the burner is completed, the supply of the start air is stopped, by, for example, closing a valve arranged in the supply lines becomes. The premix burner therefore works during normal operation unchanged and completely unaffected by the start procedure.

Fig. 1 shows a known premix burner of the double-cone type in perspective Presentation. For a better understanding of the subject, it is advantageous if at the same time Fig. 2 is used in the acquisition of FIG. 1 becomes. These two figures mainly have the purpose, the type and the functioning of such a burner.

The premix burner according to FIG. 1 consists of two hollow conical partial bodies 1, 2, which are nested offset from one another. He's going with a gaseous and / or liquid fuel 12, 16 operated. Under the The term "conical" here is not only that shown by a fixed opening angle understood cone shape understood, but it also includes others Configurations of the sub-bodies with a diffuser or diffuser-like Shape, as well as a confuser or confuser-like shape. These forms are present not specifically shown, since they are familiar to the expert are. The offset of the respective central axis or longitudinal axis of symmetry Partial body 1, 2 to each other (see. Fig. 4, Pos. 3, 4) creates on both sides, in mirror-image arrangement, each one tangential air inlet duct 5, 6 free, through which the combustion air 7 in the interior of the premix burner, i.e. in the cone cavity 8 flows. The two conical partial bodies 1, 2 each have one cylindrical initial part 9, 10, which also, analogous to the aforementioned partial bodies 1, 2, offset from each other, so that the tangential air inlet channels 5, 6 are present over the entire length of the premix burner. In the area of the cylindrical initial part is a nozzle 11 for preferably atomization a liquid fuel 12 housed such that their injection approximately with the narrowest cross section of that formed by the partial bodies 1, 2 Cone cavity 8 coincides. The injection capacity and the operating mode this nozzle 11 depends on the given parameters of the respective Premix burner. The fuel 12 injected through the nozzle 11 can be enriched with a recirculated exhaust gas if required; then is it is also possible, through the nozzle 11, the complementary injection of an amount of water to accomplish.

Of course, the premix burner can be purely conical, i.e. without a cylindrical one Initial parts 9, 10 may be formed. The sub-bodies 1, 2 also each have one Fuel line 13, 14, which runs along the tangential inlet channels 5, 6 are arranged and provided with injection openings 15, through which preferably a gaseous fuel 16 in the combustion air flowing there 7 is injected, as is symbolized by arrows 16, wherein this injection also the fuel injection level (see FIG. 4, item 22) of the Systems forms. These fuel lines 13, 14 are preferably at the latest placed at the end of the tangential inflow, before entering the cone cavity 8, this to ensure an optimal air / fuel mixture.

The premix burner has one serving as anchoring for the partial bodies 1, 2 Front plate 18, which is arranged directly on the front part of the combustion chamber 17 is.

If, as already described, the premix burner is used solely by means of a liquid Operated fuel 12, this is done via the central nozzle 11, wherein this fuel 12 then enters the cone cavity 8 at an acute angle or is injected into the combustion chamber 17. The nozzle 11 thus forms a tapered fuel profile 23 rotating from the tangentially flowing Combustion air 7 is enclosed. In the axial direction, the concentration of the injected fuel 12 continuously through the incoming combustion air 7 broken down into an optimal mixture.

If you want to operate the premix burner with a gaseous fuel 16, so this can in principle also be done via the central fuel nozzle 11, however, such an operating mode should preferably be via the injection openings 15 be made, the formation of this fuel / air mixture directly at the end of the air inlet ducts 5, 6.

When the liquid fuel 12 is injected via the nozzle 11, the end the premix burner the optimal, homogeneous fuel concentration over the Cross section reached. Is the combustion air 7 additionally preheated or with enriched with a recirculated exhaust gas, this supports the evaporation of liquid fuel 12 sustainably within the length of the premix burner induced premix section. As for the admixture of a returned Flue gas is concerned, so reference is made to Fig. 3-6.

The same considerations also apply when using fuel lines 13, 14 liquid fuels should now be supplied instead of gaseous ones.

In the design of the conical part body 1, 2 with respect to the increase the flow cross-section and the width of the tangential air inlet ducts 5, 6 are strict limits to be observed so that the desired flow field the combustion air 7 at the outlet of the premix burner can. The critical swirl number is set at the outlet of the premix burner: A backflow zone 24 (vortex breakdown) also forms there with one opposite the flame front 25 acting there stabilizing effect, in which Meaning that the backflow zone 24 functions as a disembodied flame holder takes over.

The optimal fuel concentration across the cross section is only in the area the vortex runout, that is, in the area of the backflow zone 24. First at this point a stable flame front 25 is created. The flame stabilizing one Effect results from the swirl number in in the cone cavity 8 Flow direction along the cone axis. A backlash of the flame into that This prevents the interior of the premix burner.

In general, it can be said that by adjusting the flow opening of the tangential air inlet channels 6, 7 is possible, the backflow zone 24 from the end to form the premix section. The design of the premix burner is suitable The flow opening of the tangential air inlet ducts is also excellent 5, 6 to change as required, which means without changing the overall length of the premix burner, a relatively large operating range can be recorded can.

Of course, the partial bodies 1, 2 are also in a different plane to one another slidable, which even overlaps the air inlet level into the cone cavity 8 (see FIG. 2, item 21) of the same in the area of the tangential air inlet channels 5, 6, as shown in Fig. 2, accomplished can be. It is then also possible for the partial bodies 1, 2 to be counter-rotating to interleave rotating movement in a spiral.

Through a more homogeneous mixture formation achievable in this premix burner achieved between the injected fuels 12, 16 and the combustion air 7 lower flame temperatures and thus lower pollutant emissions, in particular lower NOx values. Then reduce these lower temperatures the thermal load on the material on the burner front and make for example special treatment of the surface is not mandatory.

As far as the number of air inlet ducts is concerned, the premix burner is not open the number shown is limited. A larger number is displayed there, for example, when it comes to making the premixing wider, or the swirl number and thus the dependent formation of the backflow zone 24 by a to influence a larger number of air inlet ducts accordingly.

Premix burners of the type described here are also those which are to be achieved a swirl flow from a cylindrical or quasi-cylindrical tube go out, the inflow of combustion air into the interior of the pipe tangential air inlet channels is also accomplished, and inside of the tube a conical body with decreasing in the flow direction Cross section is arranged, which is also critical with this configuration Swirl number at the output of the burner can be achieved.

FIG. 2 shows the same premix burner according to FIG. 1, but from a different one Perspective and in a simplified representation. This Figure 2 is essentially serve to correctly record the configuration of this premix burner. In particular, the displacement of the two partial bodies 1, 2 is shown in FIG. 2 to each other, based on the main central axis 26 (= burner axis) of the premix burner, which corresponds to the main axis of the central fuel nozzle 11, quite clearly visible. This dislocation in itself induces the size of the Flow openings of the tangential air inlet ducts 5, 6. The central axis 3, 4 run parallel to each other here.

Fig. 3 is a section approximately in the middle of the premix burner. The mirror image Tangentially arranged feed channels 27, 28 perform the function of Mixing section in which the combustion air 7, formed from fresh air 29 and recirculated flue gas 30 is perfected. The combustion air 7 is in one Injector system 200 processed. Upstream of each feed channel 27, 28, the serves as a tangential inflow into the interior 8 of the premix burner the fresh air 29 evenly over the entire length of the premix burner Perforated plates 31, 32 distributed. In the direction of flow to the tangential inlet channels 5, 6 these perforated plates 31, 32 are perforated. The perforations fulfill the function individual injector nozzles 31a, 32a, which have a suction effect compared to the surrounding flue gas 30 exert such that each of these injector nozzle 31a, 32a each only sucks a certain proportion of flue gas 30, whereupon over the entire axial length of the perforated plates 31, 32, which corresponds to the burner length, a uniform flue gas admixture takes place. This configuration causes that at the point of contact of the two media, i.e. the fresh air 29 and the flue gas 30, an intimate mixing takes place, so that the up to the tangential air inlet slots 5, 6 reaching flow length of the supply channels 27, 28 can be minimized for the mixture formation. Besides The local injector configuration 200 is distinguished by the fact that the geometry the premix burner, especially what the shape and size of the tangential Air inlet ducts 5, 6 concerns, remains dimensionally stable, i.e. through the evenly dosed distribution of the hot flue gases 30 along the entire axial Length of the premix burner, there are no thermal distortions. The same injector configuration as the one just described here can also be used in the area of the head-side fuel nozzle 11 for an axial supply of a Combustion air can be provided.

4 is a schematic representation of the premix burner in the flow direction, wherein in particular the course of those belonging to the injector system 200 Perforated plates 31, 32 opposite the inflow planes 33 of the supply channels 27, 28 is expressed. This course is parallel, with the inflow planes 33 itself over the entire burner length parallel to the burner axis 26 of the Premix burner. This figure also shows how the injector nozzles 31a, 32a their inflow angle with respect to the burner axis 26 of the Change the premix burner in the direction of flow. From an initial spike They gradually align angles at the head stage of the premix burner until it is approximately perpendicular to the burner axis in the area of the outlet 26 stand. With this precaution the mixture quality of the combustion air increased and the backflow zone held stable. In other versions right-angled inflows can also be used.

5 and 6 show essentially the same configuration according to FIGS. 3 and 4, the perforated plates 34, 35 with the associated injector nozzles 34a, 35a also parallel to the inflow planes 36 over the entire length of the burner of the feed channels 27, 28 run. Meanwhile, these inflow planes 36 run conically with respect to the burner axis 26 of the premix burner. Of the variable inflow angle of the injector nozzles 34a, 35a in the flow direction also largely corresponds to the configuration according to FIGS. 3 and 4, wherein here the gradual erection of these injector nozzles 34a, 35a into one vertical inflow in the area of the outlet of the premix burner primary opposite the inflow plane 36 of the respective feed channel judges.

Fig. 7 shows a schematic partial longitudinal section of a first embodiment a premix burner for carrying out the method according to the invention, 8 the front view is shown. The basic structure of the burner corresponds the burner described in FIGS. 1 and 2. A swirl body 37 (partial cone body 1, 2) produces a swirled main flow (fuel / air mixture 39), at the downstream end of the swirl body 37 via the two each other opposite start openings 40 starting air 38 is injected purely radially. The Means 40 are connected to supply lines 41 which are independent of the starting air 38 from the burner air supply 42. The feed lines 41 can either opened or closed by means of a valve, not shown here will.

9 and 10 show a second embodiment of the premix burner. At the downstream end of the swirl generator 37 are 16 different lengths Tube 40 arranged symmetrically over the circumference of the swirl generator 37. Of course, another can in other embodiments Number of tubes 40 can be used. The tubes 40 are not as in the first Embodiment aligned purely radially, but they also have an axial and tangential directional component. They extend to the inside wall of the swirl body 37, that is up to the conical shells. This results in their different lengths. The tubes 40 are connected to a ring line 41 that brings the starting air 38 up. The start air 38 is in the counter-swirl Main flow 39 injected. Since the tubes 40 directly to the conical shells the start air jets 38 do not decay beforehand, but rather cause zones of high shear and turbulence to occur which cause the mixing intensify. As a result, the ignition conditions and flame stabilization improved. As shown in Fig. 9, the central backflow bubble becomes 24 pinched off and an intense fireball 43 is created in the immediate vicinity Near the burner.

Of course, the invention is not limited to the exemplary embodiments described here limited, but can be applied to all spin-stabilized burners.

Reference list

1, 2

conical partial body

3, 4

Central axis to item 1 and item 2

5, 6

tangential air inlet ducts

7

Combustion air

8th

Cone cavity, interior of the burner

9, 10

Cylindrical starting parts of the burner

11

Fuel nozzle

12th

Fuel, liquid fuel

13, 14

Fuel lines

15

Injection openings of the fuel line 13, 14

16

Fuel, gaseous fuel

17th

front part of the combustion chamber delimited by the aperture 103

18th

Front panel

21

Air inlet level

22

Fuel injection level

23

Fuel profile

24th

inner backflow zone, backflow bubble

24a

Backflow zone, backflow bladder without fittings in the combustion chamber

25th

Flame front

26

Main central axis, burner axis

27, 28

Feed channels for pos. 29 and pos. 30

29

Fresh air

30th

recirculated flue gas, reacted gases

31, 32

Perforated plates

31a, 32a

Injector nozzles

33

Inflow plane of the feed channels 27, 28

34, 35

Perforated plates

34a, 35a

Injector nozzles

36

Inflow plane of the feed channels 27, 28

37

Swirl generator

38

Starting air

39

Fuel / air mixture or fuel / recirculated flue gases / air mixture

40

Means for injecting item 38

41

Supply lines from item 38

42

Burner air supply

43

Fireball

200

Injector system

Claims (17)

Method for operating a fuel with gaseous and / or liquid fuels (12, 16) operated swirl-stabilized burner, in which combustion air (7) or a mixture formed by injector delivery recirculated flue gas (30) and fresh air (29) and fuel (12, 16) intensively mixed by means of a swirl generator (37) and then burned are formed, whereby a backflow zone (24) is formed which the Flame stabilized, characterized in that during the starting process at the downstream end of the swirl generator (37) from the edge of the Starting air (38) is injected into the center of the burner, which at least has a radial velocity component, and that after the end of the starting process, the injection of the starting air (38) is switched off becomes. A method according to claim 1, characterized in that the starting air (38) is injected purely radially. A method according to claim 1, characterized in that the starting air (38) is injected radially / axially. A method according to claim 1, characterized in that the starting air (38) is injected radially / tangentially. Method according to one of claims 1, 3 or 4, characterized in that that the starting air (38) is injected in counter-swirl to the fuel / air mixture (39) becomes. Burner for operating a furnace with gaseous and / or liquid fuels (12, 16) for performing the method according to claim 1, wherein the burner has a swirl generator (37) for mixing Fuel (12, 16) and combustion air (7) or a mixture of Fresh air (29) and recirculated flue gases (30) and to generate a has supercritical twist of this mixture (39), characterized in that that at the downstream end of the swirl generator (37) at least two means (40) for at least partially radial injection of starting air (38) are arranged opposite each other, which with optional closable supply lines (41) are connected. Burner according to claim 6, characterized in that the means (40) on downstream end of the swirl generator (37) symmetrically over the circumference of the swirl generator (37) are distributed. Burner according to claim 7, characterized in that the means (40) as Tubes are formed, which are designed with a ring line Supply line (41) are connected, and that the tube directly up to the inner wall of the swirl body (37). Burner according to one of claims 6 to 8, characterized in that that the burner consists of at least two hollow, conical, in Flow direction in nested partial bodies (1, 2), that the central axes (3, 4) of these partial bodies (1, 2) are offset from one another run in such a way that adjacent walls of the partial body (1, 2) Form air inlet channels (5, 6) for a combustion air (7), and that the Burner can be operated with at least one fuel nozzle (11, 15). Burner according to claim 9, characterized in that the fuel nozzle (11) is arranged on the head side and on the burner axis (26). Burner according to claim 9, characterized in that in the area of tangential air inlet channels (5, 6) in the longitudinal extension of the burner Number of spaced apart fuel nozzles (15) are. Burner according to claim 9, characterized in that the flow cross section one of the part bodies (1, 2) formed cone cavity (8) increases uniformly in the direction of flow. Burner according to claim 9, characterized in that the flow cross section one of the part bodies (1, 2) formed cone cavity (8) a diffuser, a diffuser-like course, a confuser, a confusor-like course. Burner according to claim 9, characterized in that the partial body (1, 2) are nested in a spiral. Burner according to claim 9, characterized in that in radial or quasi-radial direction with respect to the air inlet ducts (5, 6) feed ducts (27, 28), which each have at least one injector system (200) for the provision of a fresh air (29) and reacted gases (30) existing combustion air (7). Burner according to claim 9, characterized in that to the injector system (200) associated perforated plates (31, 32; 34, 35) parallel to the respective Inflow plane (33, 36) of the combustion air (7) into the feed channels (27, 28) run that the perforated plates in the area of the inflow planes are provided with injector nozzles (31a, 32a; 34a, 35a), and that the inflow angle of the injector nozzles in the axial direction of the burner is continuously changeable with respect to the burner axis (26). Burner according to claim 16, characterized in that the flow level the injector nozzles (31a, 32a; 34a, 35a) in the area of the head step of the burner has an acute angle and that this angle in axial direction of the perforated plates (31, 32; 34, 35) gradually increases until this is largely perpendicular to the area of the burner outlet Inflow planes (33, 36) of the feed channels (25, 26) and / or Burner axis (26) stands.

Images