EP2442026A1 - High temperature burner for burner operating methods with two operational states - Google Patents

Abstract

A disc-shaped mixing unit (10) has combustion air passages (21-23) that are arranged such that an outer annular space is free of combustion air passages each having radial twist angle between 5-60[deg] , while increasing combustion air quantity in radial outer direction. The setting angle of combustion air passage (23) on outermost ring is smaller than an angle of attack of combustion air passage (21) on innermost ring. Twist angle of combustion air passage (23) on outermost ring is greater than helix angle of combustion air passage (21) on innermost ring.

Description

The present patent application relates to a high-temperature burner, and more particularly to a high-temperature burner for use in a NO _x reduced-combustion burner operation method having a first start-up operation state and a second work operation state.

In the above method, the high-temperature burner for heating a furnace room operates at a working temperature in a first start-up operation state. Upon reaching a defined switching threshold (temperature furnace space, duration of the first operating state, etc.) is switched to a second operating state, the working operating state in which the NO _x -reduced combustion takes place.

Such a method is for example from the EP 0 343 746 A2 known. The burner does not work with a combustion chamber, but combustion air and fuel are passed directly into the furnace chamber, depending on the temperature in the furnace chamber. For heating the cold furnace chamber, the burner is switched to a first operating state, in which the fuel is supplied via a first fuel supply before entering the furnace chamber of the combustion air, wherein the resulting mixture is introduced from the side wall of the furnace chamber in this spaced apart. When the ignition temperature of the fuel in the furnace chamber is exceeded, the burner is switched to a second operating state by the first fuel supply is closed and a second fuel supply is opened. The second fuel supply opens at a predetermined distance from the combustion air supply and a predetermined distance from the wall of the furnace chamber in this.

An above-mentioned method with two operating states is further from the EP 0 685 683 B1 known. To heat the furnace chamber, the burner is switched to a first operating state. In this operating state, fuel is supplied to a combustion chamber via a first fuel supply, which ends in the vicinity of an outlet opening of an air supply device. In the combustion chamber, the fuel is mixed with the supplied combustion air and the resulting mixture is ignited via an ignition electrode arranged in the chamber, whereupon it burns in the combustion chamber and heats a furnace chamber associated with the combustion chamber.

As soon as the furnace chamber is heated above the ignition temperature of the fuel, the burner is switched to a second operating state by the first fuel supply is closed and a second fuel supply is opened. The second fuel supply ends approximately at the height of the outlet opening of the combustion chamber. In the second operating state, fuel is no longer supplied to the combustion chamber, so that the combustion process in the combustion chamber is substantially completely suppressed.

Furthermore, from the EP 06 754 305.8 a method for operating a high-temperature burner is known in which in a chamber, a fuel / combustion air mixture is formed and ignited by means of an ignition device, the combustion of the fuel / combustion air mixture is maintained in the chamber for a first period of time, then the fuel supply for a second period of time is reduced such that the combustion stops and remains exposed, wherein in the second period the temperature in the chamber drops below a first set temperature, and finally, after the temperature in the chamber has dropped below the first set temperature, increases the fuel supply is so that the combustion of the fuel / combustion air mixture is used due to the cooled chamber only when entering the furnace chamber and maintained.

Due to the burner assembly used in this method, compliance with the above-mentioned second period is necessary because, due to the structure of the burner used in the process, the temperature in both the chamber and the chamber wall during the first operating state over the ignition temperature of the fuel / combustion air mixture increases, and thus in the absence of the second period, no transition to the second operating state, in which the combustion is to take place exclusively in the furnace chamber, is possible. The fuel / combustion air mixture ignites in the chamber if the second time period is not met, and combustion that does not take place exclusively in the furnace space is undesirable in terms of NO _x reduction.

It is therefore an object of the present invention to provide a high-temperature burner with which a burner operating method can be carried out, which comprises a start-up operating state, and a NO _x -reduced working operating state which, however, the loss of flame for a second period of time to below a set temperature in a chamber makes superfluous.

The above-mentioned object is achieved by a high-temperature burner according to claim 1. This high-temperature burner comprises a chamber opening into a combustion chamber, leading to the chamber combustion air supply and disposed in the chamber mixing device having a plurality of combustion air passages on at least two circles the mixing device are arranged. The mixing device itself shuts off the combustion air supply to the chamber, i. The combustion air passes through the mixing device into the part of the chamber in which the combustion (start operating state) or the mixing (working operating state) takes place.

The center of the above circles on which the combustion air passages are arranged may coincide with or be offset from the axis of the chamber. It is also possible that the center of at least one circle coincides with the chamber axis, but the center of at least one further circle is offset from the chamber axis. At least one combustion air passage is arranged on each circuit, this arrangement (in the case of a circular-cylindrical configuration of the combustion air passages) being carried out such that the center of a given combustion air passage the respective circle lies. In the context of this application, the arrangement of combustion air passages "on a circle" is to say that the openings of the combustion air passages are arranged on the circle - the circles themselves are not a structural feature of the burner.

From a manufacturing point of view, it is preferred that a plurality of combustion air passages is arranged on a circle, wherein it is preferable on the same consideration that the centers of the circles coincide with the chamber axis.

The combustion air passages extend through the mixing device and are preferably made cylindrical, and from a production point of view, it is particularly preferred that these are designed circular-cylindrical.

The high-temperature burner further comprises a fuel supply, which ends in a fuel discharge device downstream of the mixing device, that is, the fuel discharge device is arranged on the furnace chamber side of the mixing device. The fuel outlet device comprises a circular cylindrical jacket and an end face or bottom closing off the fuel outlet device, wherein the jacket has a plurality of fuel passages and at least one fuel passage is assigned to the end face, whereby this fuel passage can be arranged directly in the end face or spaced therefrom (see below) ) can be arranged.

The fuel outlet device may be designed in one piece with the mixing device, or the fuel outlet device may be inserted into an opening in the mixing device. The geometry of the fuel passages is designed according to the geometry of the combustion air passages, i. a cylindrical or circular cylindrical configuration is preferred, but other designs (for example, conical) are possible.

In order to ignite the fuel / combustion air mixture during or in the start operating state, an ignition device is arranged in the chamber.

The mixing device itself, which is preferably made of a high-temperature resistant material such as ceramic or a corresponding steel alloy, is disc-shaped and is as fully as possible on the chamber wall, that is between the mixing device and the chamber wall remains in the high-temperature burner according to the invention no gap or annulus through which combustion air could enter the chamber.

The combustion air passages are further arranged on the mixing device or the at least two circles such that an outer annular space of the mixing device is free of combustion air passages. Such an arrangement of the combustion air passages has the consequence that no combustion air enters the chamber itself in the vicinity of the chamber wall.

The combustion air passages each have an angle of attack β _x > 0 ° to the chamber axis and a radial swirl angle α _x , wherein an angle of attack β _{a of} the combustion air passages on the outermost circle is smaller than an angle β _{i of} the combustion air passages on the innermost circle, and wherein the helix angle α _{a of} the combustion air passages on the outermost circle is greater than the helix angle α _i on the innermost circle, and wherein the helix angle on the outermost circle is between 5 ° and 60 °.

The combustion air passages are further arranged such that the amount of combustion air passing through the combustion air passages increases radially outward, that is, the amount of combustion air passing through the combustion air passages on the innermost circle is lower than that through the combustion air passages on the combustion air passages outermost circle passing combustion air.

The inventive combination of measures provided above in terms of the design of the mixing device, that is, the arrangement and spatial design of the combustion air passages with respect to the angle of attack, the angle of twist and the passing amount of combustion air, it is ensured that the high-temperature burner for both Start operating state and the working operating state is suitable.

The twisting of the combustion air provides stable combustion in the starting operating state of the combustion air-fuel mixture within the chamber, and the decrease of the helix angle from the outermost to the innermost circle ensures that fuel and combustion air inside the chamber are not mixed too much. Furthermore, the twisting is chosen so that in the working operating state, the combustion is not sucked into the chamber, but takes place at a convenient distance from the chamber outlet in the furnace chamber.

Excessive mixing of the fuel and the combustion air would increase the ignitability of the corresponding mixture and thus counteract the working mode in which combustion is desired only in the furnace chamber. Due to the design of the combustion air passages with a decreasing from the innermost circle to the outermost circle attack angle, but this is always greater than 0 ° relative to the chamber axis, it is achieved that the flame inward, that is to the chamber axis and away from the chamber wall, is steered.

Figuratively speaking, when arranging a plurality of combustion air passages on each circle, it can be imagined that the combustion air generates a kind of cone per circle as it flows through the combustion air passages, the cone being longer outside and shorter inside due to the larger angle of attack from outside to inside.

By increasing the amount of air passing through the combustion air passages from the inside to the outside, but supplying fuel only in the vicinity of the chamber axis, it is achieved that the fuel / combustion air mixture becomes thinner from the inside out (in terms of the fuel) and "outside" becomes a non-ignitable mixture is present.

The combination of the above measures has the consequence that in the start operating state, the flame generated in the chamber has no contact with the chamber wall, thereby ensuring that the temperature of the chamber wall during the start-up operating state does not rise above the ignition temperature of the fuel / combustion air mixture. Due to the duration of the start operating state heating of the chamber wall on the ignition temperature is excluded by the radiant heat of combustion.

The transition to the working operating state is performed such that the fuel supply is turned off for a short time, so that the combustion in the chamber stops. Immediately following we the fuel supply is started again (of course, the ignition remains disabled) and prepared in the chamber fuel / combustion air mixture can not ignite in the chamber due to the non-existent ignition source (the chamber wall is not hot enough to ignite), but only at Entry into the furnace chamber whose temperature has been set accordingly in the start operating state. In the case of the method which can be carried out with the burner according to the invention, therefore, it is not necessary to wait for a second period of time for conditions to prevail in the chamber which make it impossible to ignite the fuel / combustion air mixture.

In one exemplary embodiment of the high-temperature burner according to the invention, the end face of the fuel outlet device is assigned a plurality of fuel passages which are arranged in the end face itself and, if they are cylindrical, can be aligned parallel to the chamber axis. In order to achieve a better mixing of the fuel and of the combustion air in the vicinity of the fuel outlet device, however, it is preferred that the fuel passages arranged in the end face of the fuel outlet device have an angle of attack away from the chamber axis between 0 ° and 30 °. In the arrangement of the fuel passages in the fuel outlet device, it is further preferred that the fuel passages are arranged on or in the end face and lateral surface of the fuel outlet device such that more than 60% of the fuel passing through the gas passages exits via the end face. The emerging through the fuel passages in the face fuel reacts by design preferably, with the combustion air exiting through the combustion air passages located on the outermost circle, and by the corresponding distribution of fuel passages, the reaction is promoted in the vicinity of the axis, that is, away from the chamber wall.

In an alternative embodiment, which is particularly suitable for highly reactive fuels (with, for example, a high hydrogen content), the fuel outlet means comprises a fuel lance axially parallel to the chamber axis extending into the chamber and having the fuel passage at the lance end. At least 50% of the fuel is directed into the chamber via this lance. By concentrating the axis-parallel entry of fuel onto a fuel passage at the end of the fuel lance, combustion near the axis can also be concentrated. It is therefore increasingly ensured that the combustion takes place at a distance from the chamber wall and thus prevents excessive heating of these.

The high-temperature burner itself is exposed during startup and shutdown high temperature fluctuations, which also occur within a short period of time, so that in particular the material of the mixing device and the fuel outlet device and the chamber is exposed to high thermal requirements. With regard to the fuel outlet device has been found that it is preferred that the end face is beveled to the lateral surface, since voltages are better dissipated during heating and cooling of the fuel outlet device by this configuration of the fuel outlet device.

The combustion air passages are arranged on a plurality of circles on the mixing device, wherein the center of the circles may coincide with the chamber axis or be offset therefrom. In a preferred embodiment, the combustion air passages are arranged on three circles on the mixing device, wherein the angle of attack increases from the outermost circle to the innermost circle and the radial twist angle decreases from the outermost circle to the innermost circle. A Such arrangement of the combustion air passages on three circles on the one hand has the advantage that a corresponding mixing device is quite easy to manufacture. On the other hand, such an arrangement ensures a very uniform distribution of the combustion air in the chamber, which in turn requires a very uniform mixing of fuel and combustion air. Such uniform mixing ensures a corresponding uniform combustion in the starting state - in case of insufficient mixing occurring "local explosions", which can force the combustion to the chamber wall, omitted.

Further, it is preferable that the combustion air passages are arranged or dimensioned so that more than 75% of the combustion air amount at the outermost circle and less than 25% of the combustion air amount at the innermost circle pass through the mixer, such distribution of the passing air quantity being by the size and / or the number of combustion air passages can be achieved. With such an arrangement of the combustion air passages on the mixing device to obtain a sufficiently stable flame in the starting operating condition and further assists that in this state, the combustion does not reach the chamber wall.

In a preferred embodiment, the width of the annulus 20-40% corresponds to the average opening width of the combustion air passages on the outermost circle, wherein the average opening width in a circular cylindrical design of the combustion air passages corresponds to the diameter. It has been found that such a dimensioning of the circular space ensures ideal process control both in the start operating state and in the working operating state.

• Figur 1 eine schematische Darstellung eines ersten Ausführungsbeispiels des erfindungsgemäßen Hochtemperaturbrenners zeigt;
• Figur 2 eine schematische Darstellung eines zweiten Ausführungsbeispiels des erfindungsgemäßen Hochtemperaturbrenners zeigt;
• Figuren 3a und 3b eine Draufsicht bzw. eine Ansicht von schräg oben der Mischeinrichtung des ersten Ausführungsbeispiels zeigen;
• Figuren 4a - 4c Schnittansichten durch die in Figuren 3a und 3b gezeigte Mischeinrichtung zeigen; und
• Figur 5 eine schematische Ansicht einer Mischeinrichtung eines weiteren Ausführungsbeispiels zur Veranschaulichung der Anstellwinkel zeigt.

The invention is explained in more detail below with reference to preferred exemplary embodiments illustrated in the drawing, in which:

• FIG. 1 shows a schematic representation of a first embodiment of the high-temperature burner according to the invention;
• FIG. 2 shows a schematic representation of a second embodiment of the high-temperature burner according to the invention;
• FIGS. 3a and 3b show a plan view and a view obliquely from above of the mixing device of the first embodiment;
• FIGS. 4a-4c Section views through the in FIGS. 3a and 3b show mixing device shown; and
• FIG. 5 a schematic view of a mixing device of another embodiment for illustrating the angle of attack shows.

FIG. 1 shows a first embodiment of the high-temperature burner according to the invention. The burner has a housing 1, into which a fuel line 3a and a combustion air line 2a open. The fuel line 3a passes in the housing 1 in a fuel supply 3, and the combustion air line 2a is in a combustion air supply 2 via. To the housing joins in the longitudinal direction of a chamber 4 made of a highly heat-resistant material, in which the fuel supply 3 and the combustion air supply 2 open. For example, the chamber is made of ceramic materials or metal alloys.

The chamber 4 opens via an outlet 5 in a furnace chamber 6 or a (not shown) arranged in the furnace chamber 6 jet pipe of an industrial burner. The outlet 5 is formed by a constriction of the chamber 4 in the vicinity of the mouth of the chamber 4 in the furnace chamber 6 and is preferably rotationally symmetrical about the axis of the chamber 4. At the in FIG. 1 illustrated embodiment of the high-temperature burner, the cross-section of the chamber decreases slightly up to the constriction at the outlet 5. However, the cross-section of the chamber may also be constant over its entire length up to the constriction.

The fuel supply 3 ends at the in FIG. 1 illustrated embodiment in a fuel outlet device 9, which is arranged downstream of the mixing device 10. The fuel outlet device 9 is formed integrally with the mixing device 10, in other embodiments For example, the fuel outlet device can be inserted into an opening in the mixing device 10, ie the mixing device and the fuel outlet device are then separate components of the burner. The fuel outlet device 9 comprises a circular-cylindrical jacket and an end face closing off the fuel outlet device to the chamber, the jacket and the end face having a plurality of fuel passages 9a, 9b.

The combustion air supply 2 opens in the embodiment shown in the chamber 4, and in the chamber 4, a mixing device 10 is arranged, wherein the mixing device 10, the combustion air supply 2 terminates toward the chamber. In the embodiment shown, the mixing device 10 is spaced from the combustion air supply / chamber transition, i. the chamber itself still serves upstream of the mixing device as an air supply. In other embodiments, however, the mixing device 10 may also be arranged directly at the end of the combustion air supply 2. It is only important that the mixing device closes the combustion air supply 2 to the actual chamber 4 out.

The mixing device 10 itself is disc-shaped and lies substantially fully on the wall of the chamber 4, i. it is no or only a minor combustion air passage at the outer periphery of the mixing device possible. However, a certain passage of air between the mixing device and the chamber wall can not be completely avoided since, due to production specifications, the outer diameter of the mixing device is always minimally less than the inner diameter of the chamber wall, since otherwise the mixing device would not be able to be introduced into the combustion chamber (the ratio of gap width / diameter mixing device) is always less than 0.5%).

FIG. 2 shows a second embodiment of the high-temperature burner according to the invention, wherein this is modified compared to the first embodiment only in the area of the fuel outlet device 9. The fuel outlet device comprises a fuel lance 9c, which is designed to run parallel to the chamber axis and at its end of the lance, the fuel passage 9b. By using the fuel lance, the fuel passage assigned to the end face is thus moved further away from the end face into the chamber, ie the fuel passage is no longer located directly in the end face but is spaced therefrom.

In contrast to the first embodiment, in which the end face of the fuel outlet device is associated with a plurality of fuel passages 9b, the end face in this embodiment is therefore associated with only one fuel passage 9b.

At least 50% of the fuel is conducted into the chamber 4 via the fuel lance 9c. By concentrating the axis-parallel entry of the fuel onto a fuel passage 9b at the end of the fuel lance 9c, combustion in the vicinity of the axle can also be concentrated. It is therefore increasingly ensured that the combustion takes place at a distance from the chamber wall and thus prevents excessive heating of these.

The mixing device 10, and in particular the arrangement of the combustion air passages on or in the mixing device, will be described below with reference to FIGS FIGS. 3a, 3b . 4a, 4b . 4c and 5 described, wherein the FIGS. 3a and 3b show a plan view and a view obliquely from above of the mixing device of the first embodiment.

Like the two FIGS. 3a and 3b can be seen, in the illustrated embodiment, the combustion air passages 21, 22, 23 to three (only in FIG. 2a shown), wherein the number and the dimension of the combustion air passages 21, 22, 23 from the innermost circle a on the middle circle b toward the outermost circle c increases. The twist angle of the combustion air passages decreases from the outermost circle c toward the innermost circle a (α ₁ > α ₂ > α ₃ ), and the twist angle α _{3 of} the combustion air passages 21 on the innermost circle c is 0 ° (see in particular FIG FIGS. 4a-4c ). The angles of incidence β ₁ , β ₂ , β _{3 of} the combustion air passages 21, 22, 23 increase from the outermost circle c over the angle of incidence of the combustion air passages 22 on the middle circle b to the angle of incidence of the combustion air passages 21 on the innermost circle a toward (β ₁ <β ₂ <β ₃ ) (see in particular FIG. 5 ), wherein the angle of attack β _1, even on the outermost circle c is greater than 0 ° in order to ensure a steering of the flame in the start operating state into the interior of the chamber 4.

In the illustrated embodiment, the combustion air passages 21, 22, 23 are arranged on the mixing device, that the amount of combustion air passing through the mixing device 10 increases radially outwardly, this is achieved in the present case, that on the one hand from the inside out more combustion air passages per circle a, b, c and on the other hand from the inside to the outside larger combustion air passages per cycle are provided. In other embodiments, this can be achieved only by the number of combustion air openings per circle or only the change in dimension.

In the in the FIGS. 3a, 3b . 4a, 4b . 4c and 5 In the exemplary embodiments shown, the fuel leakage device 9 is embodied in one piece with the mixing device 10 and comprises a circular-cylindrical jacket and an end face which closes the fuel outlet device 9 toward the chamber 4. The end face is chamfered to the jacket, and thereby receives the downstream of the furnace chamber 6 facing surface of the mixing device arranged part of the fuel outlet means a pot-shaped shape. A plurality of fuel passages 9a, 9b are arranged in the lateral surface and the end face of the fuel outlet device 9, the fuel passages 9a arranged in the jacket being circular cylindrical and parallel to the surface of the mixing device, and the fuel passages 9b arranged in the end face of the fuel outlet device likewise circularly formed and have an angle of incidence away from the chamber (> 0 ° <30 °).

The mixing device 10 further comprises two circular openings 30, 40, which in the embodiments shown for receiving an ignition device 12 (not shown) and a (also not shown) flame monitoring device are provided.

The FIGS. 4a-4c illustrate the helix angles of the arranged on the circles a, b, c combustion air passages, wherein FIG. 4a a sectional view of FIG. 3a along B1 - B1, FIG. 4b a sectional view of FIG. 3a along B2 - B2 and Figure 4c a sectional view of FIG. 3a along B3 - B3. Like that FIGS. 4a-4c 2, the twist angle of the combustion air passages decreases from the innermost circle a toward the outermost circle c, and the twist angle of the combustion air passage holes on the innermost ring is 0 ° with respect to the chamber axis.

FIG. 5 is a schematic sectional view through a mixing device 10 of another embodiment in which the combustion air passages are arranged differently on or in the mixing device. Although the combustion air passages are also arranged on three circles, but the combustion air openings of adjacent circles are not offset from each other, but on a straight line from the center, so radially. At the in FIG. 5 illustrated embodiment, the decrease of the angle of attack β _x from the outermost circle to the innermost circle is shown again, in the illustrated embodiment, the angle of attack β _{3 of} the combustion air passages 21 on the innermost circle is greater than the angle β _{2 of} the combustion air passages 22 on the middle circle, which in turn is greater than the angle of attack β _{1 of} the combustion air passages 23 on the outermost circle.

At the in FIG. 5 Mixing device 10 is shown formed integrally with the fuel outlet device 9, and both the lateral surface and the end face of the fuel outlet 9 comprise a plurality of fuel passages 9a, 9b, wherein arranged in the end face fuel passages 9b have an angle of attack away from the chamber axis. This causes the emerging fuel rather, ie closer to the end face and thus closer to the furnace chamber facing surface of the mixing device 10 come into contact with the combustion air, which ensures a more homogeneous mixing fuel / combustion air, as the fuel is distributed in a larger volume.

Details of the in the FIGS. 3a, 3b and 4a-4c Mixing device 10 used in the embodiment shown are shown in the following table: Inner circle (a) Middle circle (b) Outer circle (c) Combustion air passages 6 10 12 Diameter passage / mm 5 7 13 Helix angle α / ° 0 25 45 Angle of attack β / ° 20 15 10 Circle / outside diameter mixing device 0.45 0.65 0.82 Pitch circle / mm 55 80 98

Claims (8)

A high temperature combustor for use in a NO _x reduced combustion burner operation method having a first startup operating state and a second workup operating state, with
a chamber (4) opening into a furnace chamber (6),
a combustion air supply (2) leading to the chamber, a mixing device (10) arranged in the chamber, the mixing device (10) having a plurality of combustion air passages (21, 22, 23) which are arranged on at least two circles (a, b, c) are arranged on the mixing device (10),
a fuel supply (3) which ends in a fuel outlet device (9) downstream of the mixing device (10),
wherein the fuel outlet device (9) has a circular-cylindrical jacket and an end face closing off the fuel outlet device (9), the jacket having a plurality of fuel passages (9a) and at least one fuel passage (9b) being associated with the end face, and
an ignition device (12) arranged in the chamber (4), characterized
that the mixing device (10) is disc-shaped and rests against the chamber wall, wherein the combustion air passages (21, 22, 23) are arranged on the mixing device such that an outer annular space of the mixing device (10) is free of combustion air passages, and
that the combustion air passages comprise (21, 22, 23) each have a setting angle β _x> 0 ° relative to the chamber axis and a radial twist angle α _y,
wherein an angle of incidence β _{a of} the combustion air passages (23) on the outermost ring (c) is smaller than an angle of incidence β _{i of} the combustion air passages (21) on the innermost ring (a),
wherein the helix angle α _{a of} the combustion air passages (23) on the outermost (c) ring is greater than the helix angle α _{i of} the combustion air passages (21) on the innermost (a) ring and wherein the helix angle α _{a of} the combustion air passages (23) at the outermost Ring (c) is between 5 - 60 °, and
wherein the combustion air passages (21, 22, 23) are arranged or dimensioned such that the amount of combustion air passing through the combustion air passages (21, 22, 23) increases radially outward. High-temperature burner according to claim 1, characterized in that the end face is associated with a plurality of fuel passages (9b) having an angle of attack away from the chamber axis between 0 ° and 30 °. High-temperature burner according to claim 1 or 2, characterized in that the fuel passages (9b, 9a) are arranged in the end face and lateral surface of the fuel outlet device (9) such that more than 60% of the fuel passages passing through the fuel exits via the end face. High-temperature burner according to claim 1, characterized in that the fuel outlet device (9) has an axis parallel to the chamber axis, extending into the chamber fuel lance (9c) with fuel passage (9b) at the end of the lance. High-temperature burner according to one of claims 1 to 4, characterized in that the end face of the fuel outlet device (9) is bevelled to the lateral surface. High-temperature burner according to one of claims 1 to 5, characterized in that the combustion air passages (21, 22, 23) on three circles (a, b, c) are arranged on the mixing device (10), wherein the angle of attack β _x from the outermost Circle (c) to the innermost circle (a) increases and the radial twist angle α _x from the outermost circle (c) to the innermost circle (a) decreases. High-temperature burner according to one of claims 1 to 6, characterized in that combustion air passages (21, 22, 23) are arranged or dimensioned such that more than 75% of the amount of combustion air at the outermost ring (c) and less than 25% of the amount of combustion air at the innermost ring (A) pass through the mixing device (10). High-temperature burner according to one of claims 1 to 7, characterized in that the width of the annular space is 20-40% of the average opening width of the combustion passages (23) on the outermost ring (c).

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