Burner assembly and method for operating a burner assembly

Abstract

The invention relates to a burner assembly for enabling a staged combustion, which comprises a high-impulse burner having a central fuel feed line and an oxygen feed line arranged coaxially therewith, and comprises at least one high-impulse oxygen lance which is arranged vertically above the high-impulse burner. A controller allows for switching between a stoichiometric operation of the high-impulse burner and a staged operation, in which at least a portion of the oxygen required for the stoichiometric combustion of the fuel is supplied via the at least one oxygen lance.

Description

[0001] Burner arrangement and method for operating a burner arrangement

[0002] The invention relates to a burner arrangement for enabling staged combustion in a furnace chamber. The invention further relates to a method for operating such a burner arrangement.

[0003] A well-known method for reducing NOx emissions in combustion processes is the staging of combustion air. In this process, the combustion air is fed to the flame in two or more partial streams from spatially separated positions. A portion of the combustion air is thus withheld from the main combustion zone, which generally leads to a substoichiometric combustion reaction and, in the case of carbon-containing fuels, to strong carbon monoxide production. The resulting comparatively low adiabatic combustion temperature in the main combustion zone reduces the formation of thermal nitrogen oxides. In addition, the carbon monoxide produced also directly reduces locally present nitrogen oxides. The unburned components of the fuel are afterburned by a secondary air stream at a certain distance from the main combustion zone.The most prominent examples of this type of combustion are boxer combustion systems in power plants, where the combustion air is even divided into primary, secondary and tertiary air.

[0004] Because this type of staged combustion requires a lot of space, only large combustion chambers (e.g., steam boilers in power plants) are suitable; they are generally unsuitable for use in glass melting furnaces, for example. Furthermore, the local production of large quantities of carbon monoxide is not always desirable for safety reasons, but also because of the associated disadvantages in product properties.

[0005] In contrast to air burners, oxygen burners (oxyfuel burners) use technically high-purity oxygen as an oxidizer. Especially in the case of high-temperature oxygen burners, such as those used in glass melting furnaces, where combustion chamber temperatures of 1450°C and higher are required, very high concentrations of nitrogen oxides arise due to residual nitrogen in the oxidizer or the introduction of false air into the furnace chamber and emissions from the feed materials. It has therefore already been proposed to apply the principle of staged combustion to such combustion processes as well. Due to the significantly reduced volume flow rates, oxygen burners are significantly smaller and more compact than air burners, which complicates the installation or subsequent installation of complex gas distribution systems for staging the oxygen.

[0006] Oxygen burner assemblies with staged combustion are known from EP 0 762 050 A1 and EP 3 366 994 A1. These have a flat flame burner with an oval outlet opening, from which at least one further, likewise oval-shaped outlet lance for secondary oxygen is arranged at a vertical distance. Such multiple oxygen supplies make it possible to vary the oxygen flows supplied via the burner and outlet lance(s) and to achieve different oxygen concentrations in different areas of the furnace chamber. The more oxygen is fed to the outer areas of the furnace chamber, the greater the staged combustion and thus the nitrogen oxide-reducing effect. Furthermore, staged combustion has proven particularly advantageous in glass production, where a reduced oxygen concentration below the flame creates a local atmosphere rich in carbon monoxide.The carbon monoxide counteracts the formation of foam in the molten glass and is also able to reduce foam that has already formed.

[0007] The invention is based on the object of creating an oxyfuel burner arrangement which is particularly suitable for use in glass melting furnaces and which is capable of staged combustion and which, during operation, can offer further reduced NOx emission values ​​compared to the prior art.

[0008] This object is achieved by a burner arrangement having the features of patent claim 1. Advantageous embodiments of the invention are specified in the subclaims. A burner arrangement according to the invention, by means of which staged combustion can be enabled in a furnace chamber, is equipped with a high-impulse burner mounted in a burner block, which has a fuel channel and a primary oxygen supply arranged coaxially with the fuel channel, with at least one upper oxygen lance which issues from the burner block at a vertical distance above the high-impulse burner, and with a distributor device for distributing an oxygen flow supplied to the burner arrangement from an oxygen line to the primary oxygen supply and the at least one oxygen lance.

[0009] A "high-impulse burner" is defined here as a fuel-oxygen burner designed such that, during operation of the burner, fuel and / or oxygen (oxidant) are introduced into a furnace chamber at an exit velocity of at least 50 m / s, preferably at least 100 m / s, particularly preferably at least 150 m / s. The design of the burner as a high-impulse burner leads to intensive recirculation in the furnace chamber, which lowers the flame temperature and thus inhibits the formation of NOx. Furthermore, the high exit velocities favor flow conditions that lead to temporally and spatially fluctuating concentrations of certain gases in the vicinity of the flame. As explained in more detail below, this circumstance proves to be particularly advantageous when melting glass and / or heating a glass melt, which is why the burner arrangement according to the invention is preferably intended and suitable for use in glass melting furnaces.

[0010] An "oxygen lance" is understood here to mean a device by means of which an oxygen-containing gas, in particular pure oxygen, can be introduced into a combustion chamber in a jet-like manner. The oxygen lances of the burner assembly according to the invention are preferably also designed as high-impulse lances, from which the oxygen is expelled into the furnace chamber at a velocity of at least 50 m / s, preferably at least 100 m / s, and particularly preferably at least 150 m / s.

[0011] "Pure oxygen" is understood here to mean a gas that has an oxygen content of at least 90 vol.%, preferably at least 99 vol.%. The oxidant used in the burner assembly according to the invention, in particular the high-impulse burner and the at least one oxygen lance, is preferably pure oxygen.

[0012] The fuel channel and the oxygen supply are preferably substantially cylindrical, in particular circular-cylindrical, and arranged coaxially with one another. The fuel channel can be arranged within the oxygen supply, or conversely, the oxygen supply can be arranged within the fuel supply. To increase the exit velocity, the fuel channel and / or the oxygen supply can be conically shaped in the region of their respective exit openings into the furnace chamber (burner mouth). The high-impulse burner is preferably guided through the burner block horizontally or at an inclination of less than 10° relative to the horizontal.

[0013] The at least one oxygen lance is preferably guided through the burner block parallel to the high-impulse burner axis or inclined at an angle of up to 15° toward or away from the burner axis. Geodetically speaking, it exits the burner block above the high-impulse burner, i.e., into the furnace chamber. Like the high-impulse burner, the at least one oxygen lance preferably has a circular or nearly circular cross-section.

[0014] The distribution device, which is used in addition to any existing control system for regulating the supply of the total fuel and oxygen flows, has the task of distributing the total oxygen supplied to the oxygen supply of the high-impulse burner and the at least one oxygen lance. "Distributing" here means that to set a different regular operating mode, the oxygen flows supplied by the oxygen supply or the oxygen lance(s) are not switched on or off or changed independently of one another. Instead, the total oxygen flow supplied to the burner arrangement remains the same even when the operating mode is changed and is merely distributed differently between the oxygen supply and the oxygen lance(s).The distribution device is thus designed in such a way that, during operation of the burner arrangement, the oxygen can be diverted in whole or in part from the oxygen supply to the oxygen lance(s) and vice versa; if several oxygen lances are present, the oxygen flows introduced via the individual lances can preferably also be included in the distribution and varied in the same way.

[0015] In particular, a first operating mode of the burner arrangement according to the invention can be selected in which the oxygen introduced via the high-impulse burner is substantially stoichiometric to the fuel introduced, and a second operating mode in which a substoichiometric introduction occurs via the oxygen supply of the high-impulse burner and full stoichiometricity is achieved by oxygen introduction via the at least one oxygen lance arranged above the high-impulse burner. In this second operating mode, an oxygen-poor atmosphere forms below a horizontal plane running through the mouth opening of the high-impulse burner into the furnace chamber (hereinafter referred to as the “burner plane”), in which the formation of carbon monoxide is promoted during burner operation. The high velocities of the oxygen introduced via the high-impulse burner orThe gases introduced into the oxygen lance lead to spatial and temporal fluctuations in the carbon monoxide content, which in turn reduce foam formation in a glass melt heated by the fuel arrangement according to the invention.

[0016] In an advantageous embodiment of the burner arrangement according to the invention, in addition to the at least one upper oxygen lance, at least one lower oxygen lance is provided, which exits from the burner block at a vertical distance below the high-impulse burner. This lower oxygen lance is preferably also guided through the burner block parallel to the axis or inclined at an angle of maximum 15° towards or away from the longitudinal axis of the high-impulse burner and likewise preferably has a circular or nearly circular cross-section. This embodiment allows a two-stage oxygen input. In this case, the distribution device is preferably designed such that it additionally includes the oxygen stream(s) guided through the lower oxygen lance(s) in its distribution.As a result, in particular a third operating mode of the burner arrangement according to the invention can be realized, in which an oxygen surplus is brought about in the atmosphere of the furnace chamber below the burner level, which is particularly advantageous for heating a feed material in the furnace chamber.

[0017] A compact, yet highly efficient embodiment of the burner arrangement according to the invention provides that the high-impulse burner and an oxygen lance each above and below the high-impulse burner open vertically one above the other into the furnace chamber.

[0018] A similarly advantageous embodiment of the invention provides for a plurality of upper and / or lower oxygen lances. These are, for example, two to four oxygen lances each, which preferably each open into the furnace chamber along a horizontal line and are preferably arranged symmetrically to the high-impulse burner. A circular segment-shaped arrangement of the upper and lower oxygen lances is also possible within the scope of the invention.

[0019] Preferably, the vertical distance of the upper and / or lower oxygen lances from the high-impulse burner (measured as the distance between the respective central axes) is at least 1.8 times, preferably at least 2.5 times the diameter of the high-impulse burner at its mouth into the furnace chamber.

[0020] In a particularly advantageous development of the invention, the distribution device comprises a distribution element that is fluidly connected to the oxygen line on the upstream side and, via flow passages, to the primary oxygen supply and the oxygen lance(s) on the downstream side. A distributor disc designed as a perforated disc is rotatably mounted on the distributor disc, but lockable in predetermined angular positions. The distributor disc is equipped with flow openings that interact with the flow passages of the distribution element to establish a flow connection.The flow openings, which act like a baffle, are distributed in different numbers per area on the distributor disc and / or they have different cross-sections, so that by rotating the distributor disc, the size and / or number of the flow openings interacting with a flow passage of the distribution element, and thus the total oxygen volume flow introduced into this flow passage, can be changed. In this way, the division of an oxygen flow flowing from the oxygen line into partial flows, which are guided to the furnace chamber via the primary oxygen supply and the oxygen lance(s), can be specifically varied. The angular position of the distributor disc is preferably adjustable using a servomotor and / or a hand crank.

[0021] In order to be able to adapt the distribution device to different requirements, the distribution disc is expediently detachably connected to the distribution element in order to be able to replace the distribution disc with another distribution disc that can be mounted on the distribution element and has a different number and / or size and / or geometry of flow openings.

[0022] The high-impulse burner, particularly for use in a glass melting furnace, is preferably designed for operation with a gaseous, hydrocarbon-containing fuel, such as natural gas. However, in an advantageous variant of the invention, the high-impulse burner is configured so that it can be operated with hydrogen or any hydrogen-hydrocarbon mixture as fuel instead of natural gas. "Hydrogen" is understood here to mean a gas with a hydrogen content of at least 90 vol.%, preferably at least 99 vol.%.

[0023] A preferred method for operating the burner arrangement according to the invention is claimed in claim 10.

[0024] In this method, a fuel flow through the fuel channel of the high-impulse burner, a primary oxygen flow through the oxygen supply line of the high-impulse burner, and a secondary oxygen flow through the at least one upper oxygen lance (and optionally via the at least lower oxygen lance, if present) are introduced into a furnace chamber, wherein the primary oxygen flow (including a secondary oxygen flow introduced via any lower oxygen lances present) has a substoichiometric ratio compared to the fuel flow and a ratio of fuel to oxygen that is at least stoichiometric to the fuel flow is only achieved by supplying secondary oxygen via the at least one upper oxygen lance. As a result, a region forms below the burner level in the furnace chamber with an oxygen concentration that is too low compared to stoichiometric ratios.In the case of the presence of carbon-containing compounds, for example when using a hydrocarbon-containing fuel, an area with a high carbon monoxide concentration forms there.

[0025] According to the invention, the fuel flow and the primary oxygen flow, as well as at least the secondary oxygen flow introduced via the at least one upper oxygen lance, are introduced at a velocity of at least 50 m / s, preferably at least 100 m / s, particularly preferably at least 150 m / s. Velocities above 200 m / s also produce the desired result according to the invention. For reasons not yet fully understood, the high flow velocities result in the region of low oxygen concentration or high carbon monoxide concentration that forms below the burner level not being stationary in its composition, but continuously subject to temporal and spatial fluctuations.In particular, the carbon monoxide concentration fluctuates by 10% to 100% within a few seconds during operation in a given spatial area below the burner level, with an average carbon monoxide content of at least 100 vpm, preferably at least 1000 vpm, being the desired target. This reduces foaming in a glass melt even more, particularly when used in a glass melting furnace, than would be the case in the presence of a stationary, carbon monoxide-rich atmosphere with a carbon monoxide content corresponding to the above-mentioned average carbon monoxide content. For this reason, the use of the method according to the invention in a glass melting furnace is particularly preferred.

[0026] Preferably, at least the largest portion, for example at least 60%, of the total oxygen introduced into the furnace chamber is introduced as secondary oxygen via the upper oxygen lance(s) and / or the lower oxygen lance(s); the primary oxygen flow is thus lower than the secondary oxygen flow or is even eliminated entirely. In this operating mode, NOx emissions are particularly low when using the burner arrangement according to the invention.

[0027] An embodiment of the invention will be explained in more detail with reference to the drawings. The schematic views show:

[0028] Fig. 1 : A burner arrangement according to the invention in longitudinal section

[0029] Fig. 2: The burner arrangement from Fig. 1 in a front view, seen from

[0030] Direction B in Fig. 1 ,

[0031] Fig. 3a: A distribution device for distributing the oxygen of a burner arrangement according to the invention in longitudinal section,

[0032] Fig. 3b: The distribution device from Fig. 3a in cross section along the line BB in Fig. 3a and

[0033] Fig. 3c: A device arranged in the distribution device from Fig. 3a

[0034] Distributor disc in top view.

[0035] The burner assembly 1 shown in Fig. 1 comprises a high-impulse burner 2, which is accommodated in a passage 3 of a burner quarl 4. The high-impulse burner 2 has a cylindrical, central fuel channel 5 and an oxygen supply 6 arranged coaxially around it for supplying primary oxygen. The fuel channel 5 and oxygen channel 6 open at a burner mouth 7 of the high-impulse burner 2 into a furnace chamber 8, which may be, for example, a glass melting furnace. The burner quarl 4 is mounted in a suitable passage in the wall 9 of the furnace chamber 8.

[0036] The high-impulse burner 2 is a burner in which a flow of a gaseous fuel and a flow of an oxidant are introduced into the furnace chamber 8 at a flow velocity of at least 50 m / s, preferably at least 100 m / s, particularly preferably at least 150 m / s. In such a high-impulse burner 2, the high velocity of the introduced gases leads to intensive recirculation of the combustion gases present in the furnace chamber, which results, among other things, in a reduction in the temperature of a flame forming in the furnace chamber 8 (not shown here). In order to achieve a particularly high exit velocity, the fuel channel 6 and / or oxygen supply 6, as shown here, can have a flow cross-section in the region of the burner mouth 7 that narrows conically towards the furnace chamber 8.

[0037] To enable staged combustion, the burner arrangement 1 has oxygen lances 10, 11 for introducing secondary oxygen, which in the exemplary embodiment are guided through the burner block 4 parallel to the burner axis 12 of the high-impulse burner 2. An upper oxygen lance 10 is arranged at a vertical distance from a horizontal plane (burner plane) 13 running through the axis of the high-impulse burner 2, while a lower oxygen lance 11 is arranged vertically below the burner plane 13. The vertical distance of the oxygen lances 10, 11 from the high-impulse burner 2, measured from the respective central axes, should in each case be at least 1.8 times the diameter of the high-impulse burner 2 at the burner mouth 7.

[0038] In the exemplary embodiment, the oxygen lances 10, 11 are also high-impulse introduction systems, ie the oxygen flow introduced into the furnace chamber 8 by the oxygen lances 10, 11 has a speed of at least 50 m / s, preferably at least 100 m / s, particularly preferably at least 150 m / s.

[0039] In the exemplary embodiment shown here, one oxygen lance 10, 11 is arranged one above the other, respectively, below the high-impulse burner 2 in a vertical plane 14. However, within the scope of the invention, it is also conceivable for a plurality of oxygen lances 10 (not shown here) to be provided above and / or below the burner 2; these can be arranged, for example, along a horizontal line or in another manner, for example, in a ring around the high-impulse burner 2.

[0040] The fuel channel 5 is connected via a fuel line 15 to a source of a gaseous fuel, for example, natural gas, not shown here. The oxygen supply 6 and the oxygen lances 10, 11 are connected via connecting lines 16, 17, 18 to an oxygen line 19, which in turn is connected to a source of an oxidant, for example, pure oxygen, also not shown here.

[0041] A control system 20 is arranged in the fuel line 15 and the oxygen line 19 and is in data communication with, for example, an electronic controller 21. Control valves 22, 23 are provided in the control system 20, by means of which the total flow rates of fuel and oxygen introduced into the furnace chamber 8 can be regulated depending on predetermined parameters, such as a temperature measured in the furnace chamber 8.

[0042] Furthermore, a distribution device 25 is provided in the oxygen line 19, by means of which an oxygen flow supplied via the oxygen line 19 can be variably distributed between the connecting lines 16, 17, 18, and thus between the oxygen supply 6 and the oxygen lances 10, 11. The distribution device 25 can be controlled manually or by means of the controller 21, as explained in more detail below by way of example.

[0043] During operation of the burner assembly 1, a stream of gaseous fuel is introduced into the furnace chamber 8 via the fuel line 15 and the fuel channel 5 at the high velocity described above. The fuel used may be, for example, a hydrocarbon-containing gas, such as natural gas, or a hydrogen-containing gas, or a mixture of both. At the same time, a stream of pure oxygen, which is preferably stoichiometric or slightly superstoichiometric to the fuel stream, is supplied via the oxygen line 19. The oxygen stream is fully divided between the connecting lines 16, 17, 18 in the distributor device 25 and reaches the furnace chamber 8 via the oxygen supply 6 or the oxygen lances 10, 11. There, it is ignited with the fuel stream, whereupon a flame (not shown here) forms in the furnace chamber 8.

[0044] The following operating modes are preferred: a) At least a large portion of the oxygen is directed to the oxygen supply 6. The flows of fuel and primary oxygen introduced into the furnace chamber 8 at the burner mouth 7 of the high-impulse burner 2 are therefore at least almost stoichiometric to one another. No or at most a small oxygen flow is introduced via the oxygen lances 10, 11, which merely serves to cool the oxygen lances 10, 11 and is recirculated into the latter by the high momentum of the flame, thus also contributing slightly to the combustion of the fuel in the furnace chamber 8. This operating mode is preferred, for example, when starting the high-impulse burner 2 or for heating up the furnace chamber 2. b) A large portion of the oxygen is introduced into the furnace chamber 8 via the upper oxygen lance 10 (single-stage combustion).A smaller residual flow is introduced via the oxygen supply 6 solely for the purpose of stabilizing the flame forming in front of the burner mouth 7. No oxygen flow, or at most a small one, is introduced via the oxygen lance 11; this flow merely serves to cool the oxygen lance 11 and contributes only slightly to the combustion of the fuel in the furnace chamber 8. In this operating mode, combustion below the burner level 13 is overall substoichiometric. As a result, increased carbon monoxide is formed in this area, which, when the burner assembly 1 is used in a glass melting furnace, suppresses the formation of foam on the molten glass or reduces foam that has already formed.c) All or a large portion of the oxygen is introduced into the furnace chamber 8 via the oxygen lances 10, 11 (two-stage combustion). In this case, too, oxygen-rich or oxygen-poor atmospheric regions can be created above or below the burner level 13 by varying the distribution of the oxygen flows introduced via the upper oxygen lance 10 and the lower oxygen lance 11. Any small residual flow is introduced via the oxygen supply 6 solely for the purpose of cooling the high-impulse burner 2 (if necessary) and / or for flame stabilization. In this operating mode, the high-impulse burner 2 is therefore operated significantly substoichiometrically or even only as a fuel supply. In this operating mode, particularly low levels of nitrogen oxides are produced.

[0045] These operating modes can of course also be set if, instead of the burner arrangement 1 shown here with one oxygen lance 10, 11 above or below the burner level 13, a burner arrangement according to the invention with a plurality of oxygen lances above and / or below the burner level 13 is used.

[0046] Surprisingly, it has been found that, in the operating mode of single-stage combustion (operating mode b) with the aforementioned high exit velocities of fuel and oxygen, the excess carbon monoxide occurring below the burner level 13 does not form a stationary, i.e., essentially temporally and spatially constant formation, even with a uniform input of fuel and oxygen, but rather fluctuates temporally and spatially. This effect, which may be attributable to turbulent flow processes at the interfaces between the introduced oxygen and fuel streams and the recirculating furnace gases—without limiting the invention in any way—is all the more pronounced the higher the exit velocity of the combustion gases introduced into the furnace chamber 8.In a given spatial area, the fluctuation can range between 10% and 100% of the average carbon monoxide concentration measured in that area. However, the temporal and spatial fluctuation of the carbon monoxide content in the furnace chamber 8 below the burner level 12 leads to an improved reduction in foam formation in the glass melt located in the furnace chamber 8.

[0047] With reference to Figs. 3a to 3c, a simple, robust, and cost-effective option is now described for dividing the oxygen flow supplied via the oxygen line 19 into the connecting lines 16, 17, 18 as desired. The distribution device 25 comprises a housing 26 in which a distribution element 27 is permanently mounted. The distribution element 27 is a perforated plate with three flow passages 28a, 28b, 28c, which in turn are in flow communication with the connecting lines 16, 17, 18. In the exemplary embodiment shown here, the flow passages 28a, 28b, 28c are each equally sized, circular segment-shaped openings; however, other geometries of and / or size ratios between the flow passages 28a, 28b, 28c are equally conceivable within the scope of the invention.

[0048] A distributor disc 29 is mounted on the distribution element 27 and coaxially therewith, rotatably about an axis 30 perpendicular to the surface of the distributor disc 29. This disc is also designed as a perforated disc and equipped with flow openings 31a, 31b, 31c, 31d. The flow openings 31a, 31b, 31c, 31d are arranged spaced apart from one another in the circumferential direction and, in the exemplary embodiment shown here, each have different cross-sections; alternatively or additionally, a different number of flow openings 31a, 31b, 31c, 31d can also be provided in different regions of the same surface of the distributor disc 29. The distributor disc 29 is connected via a shaft 32 to a drive arranged outside the housing 26, for example a hand crank 33 and / or a stepper motor (not shown here), which in turn can have a data connection with the controller 21.

[0049] In the position shown in Fig. 3a, the distribution element 27 and the distribution disc 29 are arranged such that the flow passage 28a and the flow opening 31a as well as the flow passage 28c and the flow opening 31c lie one above the other and in this way establish a flow connection between the oxygen line 19 and the connecting line 17 or 16 (further flow connections, not visible here, exist in this position of the distribution disc 29 between the oxygen line 19 and the connecting line 18 via the flow passage 28b and the flow opening 31b as well as between the oxygen line 19 and the connecting line 16 via the flow passage 28c and the flow opening 31d).

[0050] The housing 26, which accommodates the distribution element 27 and the distribution disc 29, is intended to ensure that all of the oxygen supplied via the oxygen line 19 passes through the flow openings 31a, 31b, 31c, 31d in the distribution disc 29 and the flow passages 28a, 28b, 28c in the distribution element 27 into the connecting lines 16, 17, 18. It is therefore connected in a gas-tight manner, for example via flange connections, to the oxygen line 19 and the connecting lines 16, 17, 18 and has a gas-tight passage 34 for the shaft 32.

[0051] Due to the different opening cross-sections of the flow openings 31a, 31b, 31c, 31d and / or the number of flow openings 31a, 31b, 31c, 31d per unit area in the distributor disc 29, rotation of the distributor disc 29 about the axis 30 causes the oxygen flow supplied from the oxygen line 19 to be distributed differently between the connecting lines 16, 17, 18 and thus between the oxygen supply 6 and the oxygen lances 10, 11. With a suitable design of the distributor disc 29, for example with differently sized flow openings 31a, 31b, 31c, 31d spaced apart in the circumferential direction, the operating modes described above can thus be easily adjusted; in particular, this does not require interrupting the operation of the burner arrangement 1 or changing the oxygen flow supplied via the oxygen line 19.

[0052] The distributor disk 29 shown here with flow openings 31a, 31b, 31c, 31d is merely an example of a possible distributor disk 29. The flow openings 31a, 31b, 31c, 31d of the distributor disk 29 are preferably designed such that the pressure loss of the burner arrangement 1 as a whole remains essentially constant even during the switching of the distributor disk 29, and thus the switching has no influence on the operation of the control system 20. The geometries suitable for this purpose and / or the required number of flow openings 31a, 31b, 31c, 31d in the distributor disk 29 depend in particular on the respective intended oxygen flows and must be determined individually, for example empirically, for each burner arrangement 1 or each furnace chamber 8.

[0053] In order to be able to adapt the distributor device 25 to different requirements, the distributor disc 29 is preferably detachably connected to the distributor element 27, and the housing 26 can be opened in a manner not shown here in order to be able to exchange the distributor disc 29, if necessary, for another distributor disc with a different number and / or size and / or geometry of the flow openings present therein.

[0054] List of reference symbols

[0055] 1 burner arrangement

[0056] 2 high-impulse burners

[0057] 3 Implementation

[0058] 4 burner stone

[0059] 5 Fuel channel

[0060] 6 Oxygen supply

[0061] 7 Brenner mouth

[0062] 8 Furnace room

[0063] 9 Wall

[0064] 10 oxygen lance

[0065] 11 Oxygen lance

[0066] 12 burner axis

[0067] 13 Brenner level

[0068] 14 Vertical plane

[0069] 15 Fuel line

[0070] 16 connecting line

[0071] 17 connecting line

[0072] 18 connecting line

[0073] 19 Oxygen line

[0074] 20 Control system

[0075] 21 Control

[0076] 22 Control valve

[0077] 23 Control valve

[0078] 24 -

[0079] 25 Distribution device

[0080] 26 housings

[0081] 27 Distribution element

[0082] 28a, 28b, 28c Flow passage

[0083] 29 Distributor disc

[0084] 30 axis

[0085] 31 a, 31 b, 31 c, 31 d flow opening

[0086] 32 Wave

[0087] 33 Hand crank

[0088] 34 Implementation

Claims

Patent claims 1. Burner arrangement for enabling staged combustion in a furnace chamber, with a high-impulse burner (2) mounted in a burner block (4), which has a fuel channel (5) and a primary oxygen supply (6) arranged coaxially to the fuel channel (5), with at least one upper oxygen lance (10) which issues from the burner block (4) at a vertical distance above the high-impulse burner (2), and with a distributor device (25) for distributing an oxygen flow supplied to the burner arrangement (1) from an oxygen line (19) to the primary oxygen supply (6) and the at least one oxygen lance (10).

2. Burner arrangement according to claim 1, characterized by at least one lower oxygen lance (11) which opens out of the burner block (4) at a vertical distance below the high-impulse burner (2).

3. Burner arrangement according to claim 1 or 2, characterized in that the high-impulse burner (2) and an upper oxygen lance (10) and a lower oxygen lance (11) each open vertically one above the other from the burner block (4).

4. Burner arrangement according to one of the preceding claims, characterized in that a plurality of upper and / or lower oxygen lances (10, 11) are provided, which open out of the burner block (4) at a distance from the high-impulse burner (2).

5. Burner arrangement according to one of the preceding claims, characterized in that the vertical distance of the upper and / or lower oxygen lances (10, 11) from the high-impulse knife (2) at the outlet from the burner block (4) is at least 1.8 times, preferably at least 2.5 times the diameter of the high-impulse burner (2).

6. Burner arrangement according to one of the preceding claims, characterized in that the distributor device (25) is connected on the upstream side to the oxygen line (19) and on the downstream side via flow passages (28a, 28b, 28c) to the primary oxygen supply (6) and the orthe oxygen lance(s) (10, 11) has a distribution element (27) which is flow-connected, and a distribution disc (29) designed as a perforated disc, which is rotatably mounted on the distribution element (27) but can be locked in predetermined angular positions and is equipped with flow openings (31a, 31b, 31c, 31d) which interact with the flow passages (28a, 28b, 28c) of the distribution element (27) to create a flow connection and which are distributed differently on the distribution disc (29) and / or have different flow cross-sections such that when the distribution disc (29) is rotated by a predetermined angle, a predetermined distribution of an oxygen flow flowing in from the oxygen line (19) to the primary oxygen supply (6) and the oxygen lance(s) (10, 11) takes place.

7. Burner arrangement according to claim 6, characterized in that the angular position of the distributor disc (29) is adjustable with a servo motor and / or with a hand crank (33).

8. Burner arrangement according to claim 6 or 7, characterized in that the distributor disc (29) is detachably connected to the distribution element (27).

9. Burner arrangement according to one of the preceding claims, characterized in that the high-impulse burner (2) can be operated with hydrogen or a hydrogen-containing gas as fuel and with pure oxygen as oxidizing agent.

10. A method for operating a burner arrangement (1) according to one of the preceding claims, in which a fuel flow through the fuel channel (5), a primary oxygen flow through the oxygen supply line (6) and a secondary oxygen flow through the at least one upper oxygen lance (10) are introduced into a furnace chamber (8), wherein the primary oxygen stream has a substoichiometric ratio compared to the fuel stream and a ratio of fuel and oxygen that is at least stoichiometric to the fuel stream is achieved by supplying secondary oxygen via the at least one upper oxygen lance (10), characterized in that the fuel stream, the primary oxygen stream and the secondary oxygen stream introduced via the at least one upper oxygen lance (10) are introduced into the furnace chamber (8) at a speed of at least 50 m / s, preferably at least 100 m / s, particularly preferably at least 150 m / s.

11. Method according to claim 10, characterized in that at least the largest part of the total oxygen introduced into the furnace chamber (8) is introduced as secondary oxygen via the at least one upper oxygen lance (10) and / or the at least one lower oxygen lance (11).

12. Method according to claim 10 or 11, characterized by the use of the burner arrangement (1) for heating the furnace chamber (8) of a glass melting furnace.

Images