Flame protection device for a burner and dry drum with such a flame protection device

Description

[0001] The invention relates to a flame protection device for a burner and a drying drum with such a flame protection device.

[0002] US 2012 / 0131812 A1 discloses a drying drum for plants for the production of bituminous macadam.

[0003] GB 2 506 440 A discloses a device for drying bulk material.

[0004] US 5,522,158 discloses a drying drum with a recirculation chamber for reducing exhaust gases.

[0005] EP 2 549 016 A1 discloses a drying drum for mixtures of white material and recycled asphalt for the production of bituminous conglomerates.

[0006] US 2015 / 030767 A1 discloses a flame protection device for a burner in a drying drum of an asphalt plant, comprising several lamellae arranged circumferentially with respect to the central longitudinal axis in a circumferential arrangement, wherein adjacent lamellae interlock with each other in a radial direction.

[0007] DE 10 2017 212 046 A1 discloses a plant for the production of asphalt. A flame tube is arranged in a drying drum to protect the burner flame. Additionally, a lamellar recuperator is arranged in the drying drum as part of a flow control unit, which serves for the targeted combustion of pollutant components in the exhaust gas and / or by-gases.

[0008] The invention is based on the objective of improving the combustion process and, in particular, reducing pollutant emissions.

[0009] The problem is solved by a flame protection device having the features of claim 1 and by a drying drum according to claim 8.

[0010] The core of the invention lies in the fact that, in a flame guard device, circumferentially adjacent lamellae can be arranged to seal against one another. A circumferential gap seal is formed between circumferentially adjacent lamellae. This means that a gap is provided between the adjacent lamellae, which decreases and, in particular, closes during operation of the flame guard device due to thermal expansion of the lamellae. This is based on the understanding that, during operation of the drying drum, temperatures in the range of 300°C to 700°C, particularly in the range of 350°C to 650°C, especially in the range of 380°C to 620°C, and especially in the range of 400°C to 600°C, are present at the flame guard device.

[0011] The circumferential gap seal, also known as a labyrinth seal, is a non-contact seal. Its sealing effect is based on the lengthening of the flow path through the gap to be sealed, which significantly increases flow resistance. This path lengthening is achieved, in particular, by the interlocking of the shaped elements of the adjacent lamellae. In a plane perpendicular to the central longitudinal axis of the flame guard, the circumferential gap seal has a non-linear shape and is, in particular, curved, at least in sections. Specifically, the circumferential gap seal is S-shaped in the plane oriented perpendicular to the central longitudinal axis.

[0012] Additionally or alternatively, the shaped elements on the side of the gap can cause turbulence of a gas flow in the flame protection device, thus achieving a higher sealing effect.

[0013] In the cold state, the gap width of the circumferential gap seal is at most 5 mm, in particular at most 4.5 mm, and in particular at most 4 mm. Relative to the sheet thickness of the lamellae, the gap width in the cold state is in particular at most 100%, in particular at most 90%, and in particular at most 80%. In particular, the gap is designed such that it reaches a minimum gap width when operating temperature is reached. The minimum gap width is in particular at most 1.0 mm, in particular at most 0.8 mm, in particular at most 0.5 mm, in particular at most 0.3 mm, and in particular at most 0.1 mm. Relative to the sheet thickness of the lamella, the minimum gap width when operating temperature is reached is at most 20%, in particular at most 15%, in particular at most 10%, in particular at most 5%, and in particular at most 2%.

[0014] The gap can also be designed in such a way that, upon reaching the operating temperature, the thermal expansion of the fins causes the adjacent fins to touch each other at least in certain areas, thus closing the gap at least partially.

[0015] The fins are made of a heat-resistant material, in particular an austenitic chromium-nickel steel, specifically material number 1.4841 according to DIN EN 10095. This material has a coefficient of thermal expansion α between 15 x 10⁻⁶ and 20 x 10⁻⁶, and in particular between 17 x 10⁻⁶ and 18 x 10⁻⁶, within the relevant temperature range. The dimensioning of the gap for the circumferential gap seal depends in particular on the material used for the fins. Other chromium-nickel steels are also possible, in particular 1.4828 or 1.4742, which is known under the trade name Sicromal 10.

[0016] The flame guard improves thermal conditions, and in particular gas flow conditions, during combustion. Thermally heated air is reliably contained within the flame guard and cannot escape through gaps between the louvers. The combustion process is more efficient, and heat losses are reduced. Because the louvers seal against each other, material being dried is prevented from unintentionally falling into the flame. Flame disturbances that could reduce combustion efficiency are reliably eliminated. The flame guard enables more efficient combustion. The emission of unwanted exhaust gases, especially the proportion of unburned hydrocarbons (Ctotal), particularly carbon monoxide (CO) and / or carbon dioxide (CO2), is reduced. The process is improved both ecologically and economically.The combustion process is more sustainable.

[0017] The louvers are arranged in particular parallel to the central longitudinal axis of the flame protection device.

[0018] The flame protection device is used for a burner that primarily produces an open flame. The burner can be operated with fossil fuels, particularly fossil energy carriers such as natural gas, liquefied petroleum gas (LPG), heating oil, and / or pulverized coal. Additionally or alternatively, the burner can be operated with renewable fuels such as wood pellets, wood dust, methane produced from biogas, and / or hydrogen gas.

[0019] The burner is primarily used to heat a drying drum, which is used in particular for heating material in an asphalt plant. The flame protection device in such a drying drum allows for an increased addition of recycled material, especially reclaimed asphalt granulate. This makes asphalt production more sustainable, as the amount of raw material used is reduced.

[0020] The flame protection device ensures straightforward and robust installation in the drying drum. In particular, it eliminates the need for a separate flame tube and a lamellar recuperator. The flame protection device according to the invention enables functional integration. The number of components is reduced. The flame protection device is simple and cost-effective.

[0021] In particular, it was recognized that it is not necessary for the louvers to overlap circumferentially and / or axially. This simplifies, in particular, the manufacture of the louvers and especially their arrangement into a flame-resistant device.

[0022] A flame guard in which the circumferential arrangement of the louvers is self-supporting offers static advantages, particularly during installation. Securing the flame guard, for example in a drying drum, is simplified. It has been recognized, in particular, that the circumferential gap seal simplifies the self-supporting function of the circumferential arrangement. Because adjacent louvers on the circumferential gap seal interlock with each other, at least partially and linearly in the radial direction, and especially alternately in the circumferential direction, no additional structural elements are required.

[0023] A flame protection device according to claim 2 enables a simple and efficient design of the gap seal. The adjacent lamellae each have sealing elements that correspond to each other. The sealing elements are arranged laterally on the lamellae. In particular, the sealing elements extend in a direction oriented parallel to the central longitudinal axis. The sealing elements are designed, in particular, as sealing strips. The sealing elements are, in particular, part of the circumferential gap seal. In particular, the sealing elements are designed such that an outer contour of one sealing element corresponds to an inner contour of the other sealing element.

[0024] A flame protection device according to claim 3 enables the uncomplicated and efficient formation of the sealing elements on the louvers. The manufacturing of the louvers with the sealing elements is simplified. The sealing elements are, in particular, designed as flanges. The sealing elements can extend along the entire length of the louvers. The sealing elements can be at least partially interrupted, in order to simplify their manufacture. The louvers exhibit increased stiffness. The risk of undesirable deformation of the louvers due to thermal stress is reduced and, in particular, eliminated.

[0025] Alternatively, it is conceivable to attach the sealing elements, in particular as pre-formed, especially strip-like, shaped elements to the lamellae, in particular by welding and / or detachably by screwing them on.

[0026] The louvers according to claim 4 are particularly easy to manufacture. Each louver has a flame-resistant section, which is particularly rectangular in design. Sealing elements are attached laterally to the flame-resistant section. The louvers can be manufactured from a sheet metal blank, particularly by forming the bends.

[0027] A louver holder according to claim 5 ensures simplified assembly. In particular, the louvers are placed on and / or attached to the louver holder. The louvers are detachably attached to the louver holder. The advantageous attachment of the louver holder to the louver reduces maximum louver deformation due to thermal expansion. In particular, the louver deformation is reduced by more than half compared to a louver according to DE 10 2017 212 046 A1, and in particular to a maximum of 40% of the deformation of such a louver. In particular, several louver holders are provided per louver, in particular exactly two louver holders per louver.

[0028] Alternatively, the lamellae can be permanently and, in particular, inseparably connected to their respective lamella holders; specifically, the lamella holders are welded to the lamellae. It is advantageous if the contact area between the lamella holder and the lamella is minimized. In particular, the lamella holder is positioned with its end face against an outer surface of the lamella. A substantially linear contact surface is formed between the lamella holder and the lamella, oriented in the circumferential direction and, in particular, perpendicular to the central longitudinal axis.

[0029] For the assembly of the flame guard, it is advantageous if the individual louvers are attached sequentially to their respective louver holders in the circumferential direction. The louvers are placed onto the louver holders. Recesses, particularly perforations, can be provided on the outer sides of the louvers to secure their position. The louver holders can engage in these recesses or perforations with corresponding projections. To complete the circumferential arrangement, the last louver is inserted axially between two adjacent louvers. This inserted louver is also referred to as the end louver. The end louver is held by an end louver holder, which differs structurally from the other louver holders.The end slat holder does not have any radially projecting protrusions on its end face that engage in the corresponding recesses and / or openings. Instead, the end slat holder has a curved contact section to which the end slats are connected, in particular welded, especially by means of spot welding.

[0030] A flame guard according to claim 6 is modular in design. In particular, the individual lamellae can be designed to be small and their length adapted to the manufacturing process. By placing several circumferential arrangements in succession, the axial extent of the flame guard can be easily extended. The flame guard can be easily adapted to the expected length of the burner flame.

[0031] In particular, an axial gap seal can be formed between circumferential arrangements arranged one behind the other.

[0032] The lamellae according to claim 7 enable a straightforward design of the axial gap seal.

[0033] A bend oriented transversely to the central longitudinal axis enables an advantageous design of the axial gap seal. The lamella is additionally stabilized and exhibits increased stiffness.

[0034] A drying drum according to claim 8 enables the advantageous execution of the combustion process with increased efficiency and / or reduced exhaust gas emissions. In particular, the drying drum enables the use of increased proportions of recycled asphalt granulate in asphalt production.

[0035] Both the features specified in the claims and those specified in the following embodiments of the flame protection device according to the invention are each suitable, individually or in combination with one another, for further developing the subject matter of the invention. The respective combinations of features do not represent any limitations with regard to further developments of the subject matter of the invention, but are essentially merely exemplary.

[0036] Further advantageous embodiments, additional features and details of the invention will become apparent from the following description of an exemplary embodiment with reference to the drawing. The drawing shows: Fig. 1 a schematic sectional view of an arrangement with a burner attached to a drying drum and a flame protection device arranged in the drying drum according to the invention, Fig. 2 a longitudinal section through the drying drum according toFig. 1 , Fig. 3 a view of the drying drum according to arrow III in Fig. 1 , Fig. 4 an enlarged partial sectional view according to section line VV in Fig. 2 , Fig. 5 a perspective view of an end face of the drying drum according to Fig. 2 , Fig. 6 an enlarged detail view of detail VI in Fig. 5 Fig. 7 a different view of the drying drum according to Fig. 5 , Fig. 8 an enlarged detail view of detail VIII in Fig. 7 , Fig. 9 a perspective single view of a lamella according to Fig. 8 .

[0037] One in Fig. 1 The arrangement designated as a whole by 1 comprises a drying drum 2, on the end face of which a burner 3 is arranged. The arrangement 1 is in particular part of an asphalt plant in which asphalt material is produced.

[0038] In the drying drum 2, white minerals are heated in a countercurrent process. This means that the material flow direction 4 and the heat propagation direction 5 are oriented in opposite directions. The drying drum 2 can also be operated in a cocurrent process. In particular, other materials, especially rock and / or recycled asphalt, can also be heated in the drying drum 2.

[0039] The burner 3 generates a burner flame 6, which extends at least partially into the drying drum 2.

[0040] A flame guard is arranged in the drying drum 2, particularly in the area of ​​the burner flame 6. The flame guard has a central longitudinal axis 7 which coincides with a rotational axis 8 of the drying drum 2.

[0041] The flame guard has several louvers 9 arranged circumferentially 10 with respect to the central longitudinal axis 7. The louvers 9 ensure that thermally heated air remains within the circumferential arrangement 10 and does not unintentionally escape, particularly in a radial direction with respect to the central longitudinal axis 7. The louvers 9 prevent material heated in the drying drum 2 from unintentionally falling into the burner flame 6 and thus adversely affecting the combustion process.

[0042] The flame protection device comprises deflector plates 11. The deflector plates 11 are arranged concentrically with respect to the central longitudinal axis 7, in particular with respect to the lamellae 9 in the drying drum 2. The deflector plates 11 are located in the flame zone of the drying drum 2. When the drying drum 2 rotates, the deflector plates 11 allow the material to be carried along, i.e., material conveyed along the material conveyance direction 4. The deflector plates 11 are designed in such a way that a material film is prevented from forming in the drying drum 2 during material conveyance. This means that when the drying drum 2 rotates about the axis of rotation 8, the material is held radially in the deflector plates 11, and in particular, only axial material conveyance along the material conveyance direction 4 occurs.In particular, the throwing plates 11 reliably prevent the material from trickling down from top to bottom in the drying drum 2 due to gravity and forming a film of material.

[0043] By carrying the material in the throwing plates 11, both the throwing plates 11 themselves and the drying drum 2 are thermally protected from the burner flame 6 and / or the heat radiation emitted by the burner flame 6. This allows the material to cool the internal components and the drying drum 2.

[0044] The blade plates 11 are fitted with lamella holders 12, which serve to hold the lamellae 9. The lamella holders 12 are attached to the blade plates 11. The lamella holders 12 extend, in particular, perpendicular to the central longitudinal axis 7 and, in particular, radially.

[0045] The flame protection device includes a baffle 13. The baffle 13 is arranged axially spaced from the lamellae 9 along the central longitudinal axis 7. The baffle 13 is disc-shaped and, in particular, substantially circular, and is fastened in the drying drum 2 by at least one baffle mounting element 14. The baffle 13 prevents the burner flame 6 from unintentionally passing into a further deflector plate area of ​​the drying drum 2 located behind the baffle 13. A material curtain is deliberately generated in this further deflector plate area. The baffle 13 prevents material damage.

[0046] The following will be based on Fig. 2 bis Fig. 9 The flame protection device is explained in more detail.

[0047] A circumferential arrangement of the louvers 9 comprises eighteen individual louvers 9. The louvers 9 are functionally identical and, in particular, have identical dimensions. Depending on the size to be formed, i.e., the clear width of the circumferential arrangement, more or fewer than eighteen louvers 9 can be used to form a circumferential arrangement.

[0048] Along the central longitudinal axis 7, four circumferential assemblies are arranged one behind the other according to the illustrated embodiment. More or fewer than four circumferential assemblies can also be arranged one behind the other. The individual circumferential assemblies are, in particular, identical in design. It is also conceivable that the circumferential assemblies have different diameters and / or are at least partially conical.

[0049] The louvers 9 each have a flame guard section 15 facing inwards, i.e., towards the burner flame 6. The flame guard section 15 has a rectangular contour with a length L and a width B. According to the illustrated embodiment, the length L of the louver 9 is greater than its width B. In particular, L ≥ 1.2 x B, in particular L ≥ 1.5 x B, in particular L ≥ 2.0 x B, in particular L ≥ 2.5 x B, and in particular L ≤ 10 x B. The louvers 9 are arranged side by side in the circumferential arrangement with respect to their longitudinal direction. In the circumferential arrangement, the louvers 9 are oriented with their longitudinal direction parallel to the central longitudinal axis 7. This means that a contour formed by the louvers 9 in a plane perpendicular to the central longitudinal axis 7 is constant along the central longitudinal axis 7.Because the flame protection sections 15 are designed to be flat, the circumferential arrangement in a plane perpendicular to the central longitudinal axis 7 has an inner contour that is essentially polygonal.

[0050] The lamellae 9 are made from material number 1.4841 from a sheet blank. The sheet thickness s is in particular in the range of 3 mm to 10 mm and especially between 5 mm and 7 mm.

[0051] The lamella 9 has sealing elements 16, 17 integrally molded onto its longitudinal edges. The sealing elements 16, 17 are designed as chamfers. The sealing elements 16, 17 are arranged to correspond with each other. The sealing elements 16, 17 form lateral sealing elements on the lamella 9. The sealing elements 16, 17 form sealing strips. The sealing elements 16, 17 are designed such that the lamella 9 are arranged alternately with the sealing elements 16, 17 around the circumference.

[0052] A first sealing element 16 essentially has an S-shaped contour. The S-contour extends, in particular, from the flame guard section 15 in a direction away from the burner flame 6. The first sealing element 16 forms a concave recess.

[0053] The second sealing element 17 has a contour corresponding to a rounded arrowhead. The second sealing element 17 forms a convexly shaped projection.

[0054] The convex outer contour of the second sealing element 17 corresponds to the concave inner contour of the first sealing element 16. In particular, the second sealing element 17 of a lamella 9 can be arranged on the first sealing element 16 of an adjacent lamella 9. This arrangement of adjacent lamellae 9 with the interlocking sealing elements 16, 17 is particularly advantageous in Fig. 4 and 6The corresponding sealing elements 16, 17 of adjacent lamellae 9 interlock, so that at most a thin air gap remains, which is in any case smaller than the sheet thickness s of the lamellae 9. In particular, the maximum gap width is at most 0.5 xs, in particular at most 0.3 xs, in particular at most 0.2 xs and in particular 0.1 x s.

[0055] This thin gap between the adjacent lamellae 9 forms a circumferential gap seal. As a result of the thermal expansion of the lamellae 9 during operation of the drying drum 2, the gap width continues to decrease.

[0056] Because the lamellae 9 of a circumferential arrangement interlock with their respective adjacent sealing elements 16, 17, the circumferential arrangement is self-supporting. This prevents the lamellae 9 from unintentionally separating from one another. The sealing elements 16, 17 ensure that the adjacent lamellae 9 interlock behind each other, making the circumferential arrangement stable in the radial direction with respect to the central longitudinal axis 7.

[0057] The lamellae 9 have a front flange 18 at a transverse edge oriented in the width direction. The front flange 18 is inclined downwards at an angle relative to the plane formed by the flame protection section 15. This angle of inclination is at most 30°, in particular at most 20°, in particular at most 15°, and in particular at most 10°. The flange 18 functions as an insertion tab, which can be inserted, in particular, into the circumferential arrangement positioned in front of it.

[0058] When several circumferential assemblies are arranged one behind the other along the central longitudinal axis 7, the lamellae 9 of the rearmost circumferential assembly are pushed under the respective lamella 9 of the circumferential assembly in front of it by means of the bend 18. This means that the bend 18 is located on the inner side of the circumferential assembly facing the burner flame 6. The bend 18 forms an axial gap seal between the circumferential assemblies arranged one behind the other along the central longitudinal axis 7. The circumferential assemblies have a high degree of tightness.

[0059] The lamellae 9 arranged one behind the other along the central longitudinal axis 7 are aligned.

[0060] Each lamella 9 is held by at least one lamella holder 19, and according to the illustrated embodiment, by two lamella holders 19. The lamella holder 19 is made from a flat sheet metal blank and has, in particular, a strip-like contour. The lamella holder 19 is, in particular, made of the same material as the lamella 9. The sheet thickness of the lamella holder is, in particular, between 8 mm and 15 mm, and, in particular, between 10 mm and 12 mm.

[0061] According to the illustrated embodiment, the louver holder 19 has projections, in particular two retaining pins, which are arranged, in particular, on its end face. The retaining pins can engage in recesses 20, which are arranged on the flame-resistant section 15. The recesses 20 are, in particular, designed as punched holes. The louver 9 is, in particular, supported or placed on the louver holder 19. The recesses 20 serve as an assembly aid for the louver holder 19 of the louver 9. In particular, the louver 9 is detachably attached to the louver holder 19. This simplifies the assembly of the circumferential arrangement. Additionally or alternatively, the louver holders 19 can also be permanently attached to the louver 9, in particular by welding.

[0062] At least one lamella 31 in each circumferential arrangement is designed differently with respect to the recesses 20. This lamella is referred to as the end lamella 31. Accordingly, the associated end lamella holders 32 for the end lamella 31 do not have protruding retaining pins, but rather a bent support tab 21, which is particularly Fig. 5 is shown.

[0063] The circumferential arrangement is formed by arranging lamellae 9 adjacent to one another in a circumferential direction 10 and placing them on the respective lamella holders 19. The lamellae 19 are stabilized on the one hand by the interlocking sealing elements 16, 17 and on the other hand by the engagement of the retaining pins in the recesses 20. The end lamella 31 is inserted axially, i.e., in a direction parallel to the central longitudinal axis 7, and engages with the two adjacent lamellae 9. The sealing elements 16, 17 ensure an undercut in the radial direction between adjacent lamellae 9 and 9, 31. The last lamella 31 to be installed is attached to the support lugs 21, in particular by welding.

[0064] By using the lamella holders 19, the lamellae 9 can be arranged in the drying drum 2 at a radial distance from an inner wall 22. The lamellae 9 form an assembly spaced from the inner wall 22 and aligned concentrically with the central longitudinal axis 7. The circumferential arrangement is essentially ring-shaped with a polygonal inner contour. The circumferential arrangement is rigidly connected to the drying drum 2. When the drying drum 2 rotates, the circumferential arrangement rotates with it.

[0065] With respect to the lamellae 9, the deflecting plates 11 are arranged radially outwards in the radial direction with respect to the axis of rotation 8. In particular, the deflecting plates 11 are arranged on the inner wall 22 of the drying drum 2.

[0066] For this purpose, retaining tabs 23 can be attached directly to the inner wall 22, in particular by welding. A mounting strip 24 is detachably attached to each of the retaining tabs 23, in particular by screwing. In particular, each throwing plate 11 is held by several, in particular three, mounting strips 24, wherein the mounting strips 24 are identical and arranged at intervals from each other along the central longitudinal axis 7.

[0067] The mounting strips 24 each have a slot-shaped receptacle 25 into which the throwing plates 11 are inserted.

[0068] The throwing plate 11 is designed in a scoop-like shape and has an L-shaped contour in a plane oriented perpendicular to the central longitudinal axis 7. The throwing plate 11 is arranged on the inner wall 22 of the drying drum 2 such that the short rib of the "L" extends substantially parallel to the inner wall 22 of the drying drum 2. "Substantially" means that the throwing plate 11 has no curvature at the inner wall 22 of the drying drum 2. To increase rigidity, the throwing plate 11 can be designed with bends. A material receiving chamber is formed between the throwing plate 11 and the inner wall 22 of the drying drum 2, which has an open rectangular contour in a plane perpendicular to the central longitudinal axis 7. The rectangle is open on one side opposite the short rib of the "L". The material receiving chamber is also open along the central longitudinal axis 7.It is possible that these end faces of the material receiving chamber are closed by separate cover elements 26. In particular, the end face of the material receiving chamber facing the material outlet of the drying drum 2 is closed by the cover element 26. The cover element 26 is attached to the discharge plate 11, in particular by welding.

[0069] The throwing plates 11, arranged one behind the other along the central longitudinal axis 7, are arranged continuously relative to each other, i.e., abutting each other at their end faces. The throwing plates 11 form the material receiving channel, which extends over several throwing plates 11.

[0070] The design of the throwing plates 11 ensures that the material to be heated is reliably carried along in the drying drum 2, but no material film is formed in the area of ​​the lamellae 9.

[0071] The short section of the "L" forms a rear wall 27 of the throwing plate 11. The lamella holders 19 of the lamellae 9 are detachably attached to the rear wall 27. According to the illustrated embodiment, a retaining bracket 28, which is preferably designed as an L-profile and allows for screwing together sheet metal sections oriented at 90° to each other, serves this purpose.

[0072] A particular advantage is that the louver holders 19 are detachably attached to the deflector plates 11. Retrofitting the louver holders 19 and / or the louvers 9 held by them is simplified. In particular, it is not necessary to attach the louvers 9 to the inner wall itself using the louver holders 19. The assembly and disassembly effort is reduced.

[0073] In particular, at least one deflector plate 11 is provided for each lamella 9. Corresponding lamellae 9 and deflector plates 11 are arranged in alignment in the radial direction with respect to the central longitudinal axis 7.

[0074] According to the illustrated embodiment, in addition to the four deflector plate arrangements, which are arranged concentrically to the respective circumferential arrangements of the lamellae 9, two further rows of deflector plates 11 are provided. No lamellae 9 are attached to these deflector plates 11. These deflector plates are therefore arranged freely.

[0075] The impact wall 13 is arranged axially spaced from the lamellae 9, and is particularly important in Fig. 3The impact wall 13 is made up of several identical impact wall segments 29, three in the illustrated embodiment. Each impact wall segment 29 has a disc section and an impact wall mounting element 14 integrally attached to it. The disc sections are each designed as a third-circle disc, i.e., with an opening angle of 120° with respect to the central longitudinal axis 7. To connect the impact wall segments 29, flange strips are bent onto the parallel wall segments 29 and bolted together. The impact wall segments 29 are attached to corresponding deflector plates 11 by means of the impact wall mounting elements 14 and a retaining tab 30 provided for this purpose.

Claims

1. A flame protection apparatus for a burner (3)in a drying drum (2) in an asphalt facility, wherein the flame protection apparatus has a central longitudinal axis (7) and a plurality of plate fins (9, 31) which are arranged in a circumferential arrangement in the circumferential direction (10) with respect to the central longitudinal axis (7), wherein plate fins (9, 31) that are arranged adjacent to one another in the circumferential direction (10) are sealed by means of a circumferential gap seal, which is a labyrinth seal, wherein adjacent plate fins (9, 31) interlock with each other at least in sections and in a linear manner in the radial direction at the circumferential gap seal, whereby the circumferential arrangement is self-supporting.

2. A flame protection apparatus according to claim 1, characterized in that plate fins (9, 31) that are arranged adjacent to one another in the circumferential direction (10) have sealing elements (16, 17) that face one another, in particular sealing strips.

3. A flame protection apparatus according to claim 2, characterized in that the sealing elements (16, 17) are formed in one piece and are designed in particular as folded edges of the plate fins (9, 31).

4. A flame protection apparatus according to any one of the preceding claims, characterized in that the plate fins (9, 31) have a flame protection section (15) that faces the central longitudinal axis (7) and is configured to be flat.

5. A flame protection apparatus according to any one of the preceding claims, characterized by at least one plate fin holder (12, 32) which is fastened to a plate fin (9, 31).

6. A flame protection apparatus according to any one of the preceding claims, characterized in that a plurality of circumferential arrangements are arranged one behind the other along the central longitudinal axis (7), wherein an axial gap seal is formed in particular between plate fins (9, 31) which are arranged adjacent to one another along the central longitudinal axis (7).

7. A flame protection apparatus according to any one of the preceding claims, characterized in that the plate fins (9, 31) have a folded edge (18) at a transverse, in particular perpendicular, orientation with respect to the central longitudinal axis (7).

8. A drying drum comprising a flame protection apparatus according to any of the preceding claims.