EP1754937A2 - Burner head and method of combusting fuel - Google Patents

Abstract

The burner head comprises a burner pipe (18) with guide plates (34) which point inwards mounted at the downstream end. A fuel injector (26) is mounted between these and has a second set of plates (24) which point outwards mounted around it. An independent claim is included for a method for burning fuel using the burner head.

Description

Field of the invention

The present invention generally relates to a combustion head and method which, when combusting gaseous and / or liquid fuels, produces a flame front spaced from the combustion head downstream in a combustion chamber.

Background of the invention

In the combustion of fossil fuels in combustion plants generally polluting emissions arise, in particular in the form of nitrogen oxides (eg NO, NO ₂ ), which are commonly referred to collectively as NOx. Pollutant emissions can be influenced and / or reduced by design measures in furnaces, especially in burners used there.

In the case of nitrogen oxides, the recirculation of exhaust gases produced during combustion has proven to be effective. Recirculated exhaust gases lower the flame temperature, reducing the amount of nitrogen oxides produced at high combustion temperatures.

DE 195 09 219 discloses a method and a burner head in which fuel gas is burned under supply of combustion air and nitrogen oxide reduction of inert gas, wherein the fuel gas is injected with respect to the combustion air in two consecutive planes in the flow direction, with a superstoichiometric combustion air-fuel gas mixture in the upstream of the flame at the flame root lying first level and with complementary fuel gas supply in the second level, and wherein serves as an inert gas recirculated exhaust gas, which is supplied in the second level, and a portion of the blown in the second level fuel gases with the recirculating exhaust gas forms a substoichiometric mixture before it is introduced into the flame.

EP 0 347 834 discloses a burner head for a blower gas burner with a device for the fuel gas distribution and the combustion air distribution, as well as fuel gas nozzles and air passage openings receiving the combustion tube and with an adjoining the combustion tube flame tube, wherein between the combustion tube and flame tube at least one radial, the exhaust gas recirculation opening is provided, and in the root region of the flame between the combustion tube and flame tube upstream of the radial opening, but are provided downstream of the fuel gas nozzles and air passage openings transversely to the burner head longitudinal axis radially inwardly projecting webs.

EP 0 635 676 discloses a method for low-NOx combustion of liquid or gaseous fuels in furnaces having a burner projecting into a combustion chamber of a boiler, the burner tube of which comprises at least one fuel nozzle arranged therein for the supply of the fuel and an adjoining baffle plate, in which a considerable part supplied to the fuel downstream of the baffle plate and adjacent to the burner tube inner wall area, located in the combustion chamber exhaust gases recirculated through internal recirculation downstream of the baffle plate built-up pressure areas in the burner tube and one or more the burner tube penetrating and projecting into the vacuum areas guide devices are used.

EP 0 857 915 discloses a method of combusting liquid and / or gaseous fuels having a burner head of a burner projecting into the combustion chamber of a boiler, the flame tube of which has at least one fuel atomizing nozzle disposed therein and a swirler, a portion of the air stream for combustion a swirler is guided, at the downstream portion of the flame tube by guiding means and openings of the flame tube, a negative pressure is generated, the exhaust gas from the combustion is mixed with the combustion air, the exhaust gas is mixed with the fuel not yet ignited in the combustion chamber, and a flame front is generated at a distance in front of the combustion head.

Overall, it should be noted that known approaches are insufficient to meet the increased requirement for emissions resulting from the operation of combustion plants, in particular in order to achieve the low nitrogen oxide emission limits, e.g. legally required.

Object of the invention

The object of the invention is to further reduce the pollutants resulting from the combustion of fuels, especially NOx emissions, compared to known approaches, in particular to allow higher combustion chamber loads at the lowest emission level.

Brief description of the invention

In one aspect, to solve this problem, the invention provides a fuel head and method of combusting fuel according to the independent claims. Further aspects and features of the invention will become apparent from the dependent claims, the following description of exemplary embodiments and the accompanying drawings.

The inventive combustion head is designed to burn liquid and / or gaseous fuels downstream with a flame front spaced from the combustion head. In contrast to conventional combustion heads in which a flame front is formed substantially immediately at downstream areas of the combustion head, the combustion head of the invention produces in operation a flame front positioned in a combustion chamber spaced from the combustion head and "free" in front of the combustion head stabilized in the combustion chamber.

The burner head comprises a burner tube having a downstream open end adapted to be disposed in a combustion chamber, at least one guide disposed at the downstream end extending radially inwardly at a first angle, i. at an angle between 0 ° and 90 ° in the direction of the burner tube axis, and one or more fuel nozzles arranged in the burner tube.

Preferably, a plurality of guide means are provided which are spaced from each other and extend radially inwardly and in the downstream direction at the first angle.

In another embodiment, the or each baffle may extend radially inwardly and in the direction perpendicular to the torch tube axis or at the first angle radially inward and in the downstream direction at the first angle.

In the latter embodiment, the at least one guide device extends obliquely to the longitudinal axis of the burner tube, wherein radially inner regions of the at least one guide device are spaced further from the open end of the burner tube than radially outer regions.

The fuel nozzle (s) is / are preferably configured to deliver fuel at the downstream end at a second angle radially outward in the downstream direction toward the at least one nozzle and into the combustion chamber during operation. In other words, the fuel nozzle (s) operatively emit fuel adjacent to the open end of the combustor so as to provide a fuel flow or jet that extends obliquely outwardly from radially inward regions of the burner tube extends radially outer regions of the burner tube, where it to the at least one guide and / or, if present, through the spaces between the several guide means is discharged into the combustion chamber.

The at least one guide means may comprise a ring located at the downstream end or a disc having a central opening. This embodiment can be achieved by a guide device embodied as a separate component or by a baffle plate described below at least partially providing the function of the guide device.

Alternatively or additionally, a plurality of guide means may be provided, which are at least partially spaced from each other so that there are gaps between the guide means.

In one embodiment, the or each baffle may each include an area that may be flown with fuel discharged from the fuel nozzles. In particular, these surfaces may be delta-shaped.

Preferably, the fuel nozzle (s) is configured to deliver fuel at the second angle and toward the at least one nozzle and / or toward the spaces between nozzles. This can be done for example by an angle to the longitudinal axis of the burner tube or to its radial direction arrangement of the fuel nozzles at the open end of the burner tube and / or by appropriately directed outlet openings of the fuel nozzles.

According to a preferred embodiment, the fuel nozzles are suitable for delivering gaseous fuel. However, it is also provided to supply liquid fuel by means of at least one or more additional fuel nozzles.

Preferably, a plurality of fuel nozzles at the open end of the burner tube are each arranged between one of the intermediate spaces between guide devices.

According to one embodiment, the combustion head comprises an annular disc which acts as a baffle plate. The disc is attached to the open end of the burner tube and extends there from the burner tube substantially radially inwardly, in particular perpendicular to the longitudinal axis of the burner tube.

According to a preferred embodiment, the disc is designed to act at least partially as a guide, in particular radially inner portions of the disc. It is also envisaged that the disc serves as a guide as a whole and thereby also exercises the storage function.

According to a further embodiment, it is possible to carry out the disc as a separate component and to arrange the at least one guide device on the disc. In this case, in the case of, for example, an annular guide device, the guide device can extend radially inward and in the downstream direction from radially inner regions of the disk at the first angle.

When using multiple vanes, they may be attached to radially inner portions of the disk, more particularly substantially immediately on the inner circumference of the disk (i.e., the disk rim defining the opening of the annular disk) and extending radially inwardly therefrom at the first angle.

Depending on the application of the combustion head, for example in a firing plant for gaseous and liquid fuel, at least one further fuel nozzle may be present. Preferably, the at least one further fuel nozzle is designed to radially spear-shaped fuel under a spray angle (third angle) determined by the atomizer nozzle to surrender to the outside. According to a further embodiment, when using steam or air atomizing nozzles, the fuel is introduced in a plurality of fuel jets at an angle to the burner tube axis radially outward between the guide devices. This has, for example, the advantage of being able to select the fuel supply as a function of the fuel in order to optimize its combustion.

When the above-mentioned gaseous fuel nozzles are provided, it is preferable that the at least one other fuel nozzle emit liquid fuel during operation. However, the at least one further fuel nozzle can also be designed for the supply of gaseous fuel. The same applies in the event that the above-mentioned fuel nozzles to supply liquid fuel.

Preferably, the combustion head also has a swirling device, for example in the form of a swirling body that is stationary or displaceable in the longitudinal direction of the burner tube, in order to displace combustion air that can be supplied through the burner tube, in particular its central, central region, ie to displace it with a swirling impulse. It is provided to arrange the swirl device upstream of the fuel nozzles in the combustion tube.

According to a further preferred embodiment, the combustion head comprises a so-called pilot burner or auxiliary burner. With the pilot burner combustion gases can be supplied, which can provide in operation for preheating to a priming (without forming a flame front) of fuel, whereby a stabilization of the spaced apart from the combustion head flame front can be achieved. Preferably, the pilot burner is disposed upstream of the fuel nozzles in the combustion tube and, if present, upstream of the swirl means.

Preferably, the first angle is in a range between about 35 ° and 65 °.

Preferably, the second angle is in a range between about 30 ° and 60 °.

In the method of the invention, fuel is burned using a combustion head having a burner tube having a downstream open end extending into a combustion chamber and at least one guide disposed at the downstream end radially radial at a first angle extends inwards. The corresponding design above apply here accordingly.

In the method of the present invention, fuel is discharged at the downstream end at a second angle radially outward toward the nozzles and into the combustion chamber.

Furthermore, in the method according to the invention, a flame front is produced at a distance downstream of the combustion head, that is, a flame front stabilizing "free" in front of the combustion head in the combustion chamber.

Preferably, the fuel is delivered at the second angle toward the at least one nozzle and / or, if present, toward interstices between nozzles.

According to one embodiment, it is preferred that the fuel is discharged so that it mixes intensively with the combustion air and the recirculated gases downstream of the burner tube in the region of the guide means. As a result, only a small excess of air is required for the operation of the combustion head, which comes very close to the stoichiometric fuel-air ratio.

To stabilize the flame front, an initial ignition of fuel in front of the flame front can be effected, for example, by means of a pilot burner upstream of the fuel supply hot combustion gas is generated and introduced into the flame root.

Preferably, the fuel discharged at the second angle is delivered in a range between about 30 ° and 60 °.

In a further aspect, the present invention provides a method of combusting fuel using a combustion head having a burner tube extending partially into a combustion chamber, wherein a free flame front is created in the combustion chamber from and downstream of the combustion tube, and vacuum zones in the combustion chamber be formed with fluidized areas so that in the combustion chamber existing exhaust gases are recirculated inside the combustion chamber and mixed with over the burner tube at the downstream end at an angle radially outward in the downstream direction supplied fuel.

Brief description of the figures

Fig. 1a und 1b

schematische Darstellungen einer bevorzugten Ausführungsform der vorliegenden Erfindung, in Schnittdarstellung und als Ansicht aus Richtung des Brennraumes; und

Fig. 2

eine schematische Darstellung eines Betriebszustands bei Verwendung eines erfindungsgemäßen Brennkopfs.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, in which:

Fig. 1a and 1b

schematic representations of a preferred embodiment of the present invention, in sectional view and as a view from the direction of the combustion chamber; and

Fig. 2

a schematic representation of an operating state when using a burner head according to the invention.

Description of preferred embodiments

1a and 1b show schematic representations of a designated as a whole with 2 Brennkopfs.

The combustion head comprises a housing 4 with which the combustion head 2 can be fastened, for example, to corresponding areas and / or components of a firing installation.

For the supply of gaseous fuels, a first port 6 and for the supply of liquid fuels, a second port 8 is provided, each of which can be connected to corresponding fuel sources (not shown) to receive fuel therefrom.

Gaseous fuel is supplied via the first port 6 to a fuel gas pipe 10, which comprises a region formed as a double-walled tube 12 area.

Liquid fuel is supplied via the second connection 8 to a fuel rod 14, which is partially enclosed by the double-jacket tube 12.

The fuel rod 14 is connected by an auxiliary device, e.g. a linear actuator axially displaceable in the double jacket tube. During operation of the gaseous fuel burner head, this fuel rod and attached fuel nozzle 26 may be withdrawn into the jacketed tube to prevent thermal overloading of the fuel nozzle.

At its left in Fig. 1a end, the housing 4 has an opening 16 through which the combustion head 2 combustion air can be supplied.

At the opposite end of the housing 4, a burner tube 18 is fixed, through which the double-jacket tube 12 and the Fuel nozzle linkage 14, as seen in Fig. 1a, extend.

Due to the supply of combustion air via the opening 16 and due to the guidance of fuel in the longitudinal direction of the combustion head 2 and in particular of the burner tube 18, the direction indicated by the arrow 20 is referred to as downstream, while the direction indicated by the arrow 22 is referred to as upstream.

At the downstream end of the double-walled tube 12, fuel nozzles 24 are arranged. The fuel nozzles 24 are directed obliquely in the direction downstream with respect to the longitudinal axis of the burner tube 18, in other words extend at an angle radially outward. It is understood that the orientation of the fuel nozzles 24 also determines the direction in which they emit fuel. That is, in the embodiment illustrated here, the fuel nozzles 24 deliver fuel radially outward at an angle. This fuel discharge direction can also be achieved, for example, by having the double-jacket tube 12 at its downstream end fuel outlet openings which allow a discharge of fuel at an angle radially outward and / or, for example, at the downstream end of the double-jacket tube 12 fuel substantially in the longitudinal direction the burner tube 18 is discharged and deflected by deflection at an angle radially outward.

At its downstream end, the fuel nozzle linkage 14 has another fuel nozzle 26, which can deliver fuel as a spray with different spray angles and profiles.

At its upstream end 28, the burner tube 18 is open in order to be able to receive combustion air supplied via the opening 16. At the downstream end 30 of the burner tube 18, an annular disc 32 is arranged.

The disc 32 may also be referred to as a baffle plate, since it jams toward downstream flowing combustion air and, if present, fuel and redirects to the center of the downstream end 30 of the burner tube 18. At the inner edge of the baffle plate 32, which limits the central opening, guide devices 34 are arranged. Manufacturing technology, the burner tube 18, the disc 32 and the guide means 34 may be provided as separate components or integrally formed.

The guide means 34 extend obliquely inwards, starting from the disc 32, in the direction downstream, in other words at an angle radially inwards and in the direction downstream. In the illustrated embodiment, the vanes 34 are formed by delta-shaped, triangular surfaces.

The fuel nozzles 24 are each designed and / or arranged so that they do not direct fuel directly to the guide 34, but in the direction of the spaces between the guide 34th

Upstream of the fuel nozzles 24 and 26, a swirl device or a swirl body 36 is provided on the double-walled tube 12 in a circumferential manner. With the swirl device 36, supplied combustion air or at least a part thereof (eg, the central, central area) imparted a swirl pulse, so that an internal swirl flow is generated downstream of the swirl device 36. The diameter of the swirling device 36 and the distance to the disc 32 affect the pulse ratio between the twisted combustion air and the untwisted air flowing between the swirling device 36 and the burner tube 18. Advantageously, the swirl device 36 is displaceable in the longitudinal direction of the burner tube 18, so that an adjustment of the swirl device 36 relative to the plate 32 or the guide devices 34 provides a flow characteristic which is described below. and pressure ratios upstream and downstream of the disc 32 and the guide 34 optimized swirl flow is generated.

In particular, when operating with liquid fuel of the swirl pulse is at least partially on the emerging from the nozzle 26 fuel spray.

Upstream of the swirl device 36, a pilot burner or support burner 38 is arranged. The pilot burner 38 is used, in particular, at partial load operation to dispense combustion gases that can provide heating up to initiation of fuel output by the fuel nozzles 24 and / or 26. This "pretreatment" of fuel is used in particular for additional stabilization of a flame front, which is described in more detail below and is formed from the combustion head 2.

An embodiment of the method according to the invention and the operation of the burner head according to the invention are explained in more detail below with reference to FIG. 2.

FIG. 2 schematically illustrates the use of the combustion head 2 of FIGS. 1a and 1b in a firing plant indicated in FIG. 2. Due to the rotationally symmetrical construction of the combustion plant and the combustion head 2 assumed here and the states occurring during operation, FIG with respect to an axis of symmetry 40 schematic sectional view.

The combustion head 2, more precisely a downstream region of the burner tube 18, projects into a combustion chamber 42. The combustion chamber 42 is bounded by walls 44.

In operation, the combustion air flowing against the disc 32 and the guide means 34 causes, on the disc 32 and on the guide means 34 downstream, the means at the side facing in the combustion chamber 42 sides of the disc 32 and the guide means 34, form negative pressure zones with fluidized areas. In particular, two counter-rotating swirl pots 46 and 48 are formed on each baffle 34, which can extend far into a flame front 50 which is formed downstream of the burner head 2 and spaced therefrom. The vacuum zones and fluidized areas, in particular the vortex chambers 46 and 48, provide for an intensive, combustion chamber internal recirculation of gases or exhaust gases present in the combustion chamber 42, which are formed during combustion of fuel supplied by the combustion head 2. At the same time, the fluidized areas provide for intensive mixing of recirculated combustion exhaust gases and supplied fuel.

In the case of the combustion head 2, the flame front 50 does not form directly on the combustion head 2 itself, but is "free" in the combustion chamber 42. The flame front 50, which is spaced from the combustion head 2, permits mixing of recirculated combustion exhaust gases and supplied fuel, as a result of which the flame temperature reduced and resulting in combustion nitrogen oxides are reduced. Furthermore, the flame front 50, which is at a distance from the combustion head 2, makes it possible to prepare fuel in more detail below.

Due to its discharge pulse and the above-mentioned negative pressure zones and fluidized areas, fuel supplied by means of the fuel nozzles 24 and / or 26 (the latter not shown in FIG. 2) reaches the regions of the combustion chamber 42 in which the vortex plug 48 is present. This area is referred to below as the outer recirculation zone. In the outer recirculation zone there is formation of a strong fuel enrichment with a substoichiometric, reducing acting atmosphere.

In the case of a liquid fuel, such as oil, fuel in the outer recirculation zone is already more gasified compared to the prior art, because of the Vacuum zones and vortex regions downstream of the disc 32 and the guide means 34 recirculated combustion exhaust gases at the end 30 of the burner tube 18 are sucked circumferentially.

In general, but in particular in the case of gaseous fuel, which is supplied by means of fuel nozzles 24, it comes in the outer, surrounding the combustion head return zone - in addition to the above-described combustion chamber internal exhaust gas recirculation especially inert combustion exhaust gases and their mixing with fuel - for a treatment and / or Disassembly of fuel.

In particular, there is a splitting of fuel molecules into radicals in the outer recirculation zone and at least a partial oxidation of fuel.

CO₂:

etwa 11,3 Vol.-%

O₂:

etwa 0,1 Vol.-%%

CO:

mehr als etwa 1,0 %Vol.-%

C_xH_y:

etwa 0,05 ... 0,1 Vol.-%

Experiments with a combustion head according to the invention with a power of about 2300 kW have, inter alia, delivered the following measurement results in areas around the combustion head:

CO ₂ :

about 11.3% by volume

O ₂ :

about 0.1% by volume

CO:

more than about 1.0% vol.%

C _x H _y :

about 0.05 ... 0.1 vol.%

In the outer recirculation zone, therefore, there is a mixture with low oxygen content and high loading of carbon monoxide (CO) and unburned hydrocarbons (C _x H _y ). At least partially higher CO ₂ values than in or behind the flame at the end of the combustion chamber were found. Overall, these and other experiments prove a treatment and / or decomposition of fuel in the outer recirculation zone.

Resulting radicals are - at least partially sucked by the combustion head 2 - mixed with exhaust gases from the flame. The radicals are reactive and ignite at least partially downstream of the combustion head 2 in areas where in which recirculated combustion gas mixes with the combustion head 2 at the upstream end of supplied combustion air. Thereby, the oxygen partial pressure of the combustion air is lowered in addition to the loading of the combustion air flow with recirculated, inert combustion gases, before the mixture of combustion air and recirculated combustion gases can mix with fuel and ignite.

The radicals and reaction products formed in the processing and / or decomposition of fuel (eg CH, HCH, CH ₃ , OH and CO) represent unstable reaction intermediates within flames. In comparison, it is advantageous, for example stable methane molecules (CH ₄ ) for First decompose combustion into reaction intermediates before the final combustion products (eg CO ₂ , H ₂ O) are formed by completing the combustion process.

Such a decomposition of stable components (eg methane molecules) into radicals and an associated oxidation process starts with an endothermic reaction, such as:

CH ₄ → CH ₃ + H (with, for example, about -38 kJ / mol)

For this reason, the combustion of the combustible constituents diluted with recirculated inert combustion exhaust gas downstream of the combustion head 2, on the one hand, proceeds slowly enough to avoid the formation of regions with high (combustion) temperatures. On the other hand, this combustion proceeds fast enough to thermally stabilize the flame front 50 spaced from the combustion head 2 by heat of oxidation and the oxygen partial pressure of the mixture of combustion air and recirculated combustion exhaust gas through the binding of oxygen for the oxidation of the radicals and partially combusted constituents (especially partially combusted gases) reduce.

By the suction of inert gases and radicals or partially combusted gases in the vacuum zones of the guide devices 34 and the disc 32 only a small mixing energy for mixing the streams is needed because the mixing process at least partially before the start of the combustion process - and thus in a relatively cold zone is carried out. In this, the material flows have a low viscosity. The viscosity of air and exhaust gas is known to increase strongly with temperature, so that the incorporation of exhaust gases directly into the flame region would require significantly higher mixing energies.

The proportion of reductive CO in the recirculated combustion exhaust gas prevents formation of hot flame because CO has a lower laminar flame velocity compared to methane. The flame temperature is additionally reduced, whereby the amount of nitrogen oxides produced during the combustion can be kept at a low level. This is confirmed by tests in which even at high combustion chamber load least amounts of nitrogen oxide were found - which are significantly lower than those of the known methods. Furthermore, the combustion proceeds more stably compared with known approaches, in particular, the combustion pulsations which are generally customary at high recirculation rates of combustion exhaust gases are absent.

The above statements with regard to the outer return zone also apply to the areas in the combustion chamber 42 in which the vortex plug 46 is formed. These areas are collectively referred to as the inner recirculation zone.

There, especially in the area between the 2 burner head and the flame front 50, the crossing of the material flows is extremely effective. While the fuel passes through the fuel nozzles 24 and / or 26 at an angle in the radial direction from the longitudinal axis of the combustion head 2 to the outer recirculation zone recirculated exhaust gas is directed substantially by the arrangement of the nozzles 34 in the core zone of the flame in the vicinity of the flame axis. This creates a combustion chamber internal fuel processing mechanism that spatially separates the formation and oxidation of radicals. As mentioned above, in addition to the recirculation of exhaust gases from the flame, the return head (s) around the combustion head 2 formed by the combustion chamber walls 44, the combustion head 2 and the flame front 50 also undergo (thermal) fuel treatment ,

The present invention allows compared to the prior art, a further reduction of nitrogen oxides in exhaust gases of combustion plants, especially in gas, fuel oil and multi-fuel burners, achieved by the above-described fuel treatment and / or fuel decomposition in particular in radicals in the areas in the combustion gases be returned to interact with supplied fuel.

Further, the present invention improves the stability of the "free" flame front, especially when a pilot burner is used in partial load operation to achieve preheat to fuel priming.

In the case of liquid fuel, the present invention also reduces the formation of soot, especially in the areas in which combustion gases of the combustion chamber are recycled, because the recirculation and / or mixing of the combustion gases circumferentially on the inner edge of the disc 32 and in addition to the edges of the guide 34 takes place. As a result, the pre-gasification of the fuel spray is substantially improved and intensifies the mixing of the recirculated gases with the combustion air.

Claims (32)

A combustion head for combusting fuel having a flame front spaced from the combustion head downstream, comprising: a burner tube (18) having a downstream open end (30) provided for placement in a combustion chamber, - At least one at the downstream end (30) arranged guide means (32; 34) extending radially inwardly at a first angle, and at least one fuel nozzle (24; 26) provided in or on the burner tube (18) arranged and / or configured to direct fuel at the downstream end (30) radially outward at a second angle and toward the downstream direction at least one guide device (32; 34) to deliver into the combustion chamber. A burner head according to claim 1, wherein - A plurality of guide means (34) which are spaced from each other at the first angle radially inwardly and extend downstream. A burner head according to claim 1, wherein - The at least one guide device (32) extends radially inwardly and in the direction perpendicular to the burner tube axis. A burner head according to claim 1, wherein - The at least one guide device (32) comprises a closed ring which extends radially inwardly at the first angle. A burner head according to claims, wherein - The plurality of guide means (34) comprise regions which are spaced from each other and form spaces. A burner head according to claim 5, wherein - The or each fuel nozzle (24; 26)) is designed to emit fuel at the second angle in the direction of the spaces between the guide means (34). A burner head according to any one of the preceding claims, wherein - The or each fuel nozzle (24; 26)) is designed to deliver gaseous fuel. A burner head according to any one of claims 5 to 7, wherein - Each of the fuel nozzles (24; 26)) is in each case arranged between one of the intermediate spaces between the guide devices (34). A burner head according to any one of claims 2-8, wherein - The guide means (34) each have a delta-shaped surface (32). Firing head according to one of the preceding claims, with - An annular disc (32) extending radially inwardly from the downstream end (30). A burner head according to claim 10, wherein - The at least one guide device (34) from the inner periphery of the disc (32) at the first angle extends radially inwardly, or - The disc (32) at least partially from the at least one guide device (32, 34) is included. Firing head according to one of the preceding claims, with - Another fuel nozzle (26) which is designed to deliver fuel at a third angle radially outward in the direction downstream and in the direction of the at least one guide device (32, 34). A burner head according to claim 12, wherein - The further fuel nozzle (26) is designed to deliver liquid fuel. Firing head according to one of the preceding claims, with - A swirl means (36) which upstream of the fuel nozzles (24, 26) in the combustion tube (18) is arranged. Firing head according to one of the preceding claims, with a pilot burner (38) disposed upstream of the fuel nozzles (24, 26) in the combustion tube (18). A burner head according to claim 15 as far as dependent on claim 14, wherein - The swirl device (36) downstream of the pilot burner (38) is arranged. A burner head according to any one of the preceding claims, wherein - The first angle is in a range between about 35 ° and 65 °. A burner head according to any one of the preceding claims, wherein - The second angle is in a range between about 30 ° and 60 °. A method of combusting fuel using a burner head having a burner tube having a downstream open end extending into a combustion chamber and at least one guide disposed at the downstream end extending radially inwardly at a first angle, wherein in the process: - Fuel is discharged at the downstream end at a second angle radially outward in the direction downstream and in the direction of the at least one guide to in the combustion chamber, and - A flame front is generated at a distance downstream of the burner head. The method of claim 19, wherein - The fuel at the second angle in the direction of gaps between a plurality of guide means, which are spaced from each other and form spaces, is discharged. A method according to claim 19 or 20, wherein - The fuel is discharged so that form downstream of each guide vacuum zones with one or more vortex regions. A method according to any one of claims 19 to 21, wherein - The fuel is gaseous fuel. A method according to any one of claims 19 to 22, wherein - To deliver another fuel at a third angle radially outward in the direction downstream and in the direction of the at least one guide. A method according to claim 23, wherein - the other fuel is liquid fuel. A method according to any one of claims 19 to 24, wherein combustion gas is generated upstream of the fuel supply to cause initial ignition of fuel in front of the flame front to stabilize the flame front. A method according to any one of claims 19 to 25, wherein - The fuel discharged at the second angle is discharged in a range between about 30 ° and 60 °. A method of combusting fuel using a burner head having a burner tube extending partially into a combustion chamber, the method comprising: - In the combustion chamber existed by the combustion tube and downstream of the same a free flame front is generated, and - Be formed in the combustion chamber vacuum zones with fluidized areas so that in the combustion chamber existing exhaust gases be recirculated within the combustion chamber and mixed with fuel, which is supplied via the burner tube at the downstream end at an angle radially outward in the downstream direction. A method according to claim 27, wherein
in the vortex regions opposite vortex braids are generated. The method of claim 28, wherein
In an outer vortex zone comprising an outer return zone and / or an inner return zone comprising an inner vortex zone, fuel enrichment with a substoichiometric reducing atmosphere is generated. The method of claim 29, wherein
In the at least one recirculation zone, molecules of the fuel are at least partially decomposed into radicals and / or fuel is at least partially oxidized. The method of claim 30, wherein
Radicals are sucked together with recirculated exhaust gases of the combustion chamber at least partially using the combustion head. A method according to claim 31, wherein
sucked in radicals are at least partially ignited in areas where recirculated exhaust gases of the combustion chamber mix with the combustion air supplied to the combustion head at an upstream end thereof.

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