Flame protection device for a burner, lamella for such a flame protection device and drying drum with such a flame protection device

Abstract

A flame protection device for a burner (3), in particular in a drying drum (2), in particular in an asphalt plant, has a central longitudinal axis (7) and several lamellae (9, 31) which are arranged in a circumferential arrangement in the circumferential direction (10) with respect to the central longitudinal axis (7), wherein lamellae (9, 31) arranged adjacent in the circumferential direction (10) are sealed by means of a circumferential gap seal.

Description

[0001] The content of the German patent application DE 10 2022 211 106.0 is incorporated herein by reference.

[0002] The invention relates to a flame protection device for a burner, a lamella for such a flame protection device and a drying drum with such a flame protection device.

[0003] DE 10 2017 212 046 A1 discloses a plant for producing asphalt. A flame tube is arranged in a drying drum to protect the burner flame. Additionally, a plate-type recuperator is arranged in the drying drum as part of a flow control unit, which serves to selectively combust pollutant components in the exhaust gas and / or secondary exhaust gases.

[0004] The invention is based on the object of improving the combustion process and in particular reducing pollutant emissions.

[0005] The object is achieved by a flame protection device having the features of claim 1, by a lamella according to claim 9 and by a drying drum according to claim 10.

[0006] The core of the invention is that, in a flame protection device, lamellae arranged adjacently in the circumferential direction can be arranged in a sealing manner against one another. A circumferential gap seal is formed between lamellae arranged adjacently in the circumferential direction. This means that a gap is formed between the adjacent lamellae which, during operation of the flame protection device, decreases and, in particular, closes as a result of thermal expansion of the lamellae. This is based on the knowledge that, during operation of the drying drum, temperatures in a range of 300°C to 700°C, in particular in a range of 350°C to 650°C, in particular in a range of 380°C to 620°C, and in particular in a range of 400°C to 600°C are present at the flame protection device.

[0007] The circumferential gap seal, also known as a labyrinth seal, is particularly a non-contact seal. The sealing effect is based on the extension of the flow path through the gap to be sealed, which significantly increases flow resistance. This path extension is achieved in particular by the interlocking of shaped elements of the adjacent lamellae. In a plane perpendicular to the central longitudinal axis of the flame protection device, the circumferential gap seal has a non-linear shape and is, in particular, curved at least in sections. In particular, the circumferential gap seal is S-shaped in the plane oriented perpendicular to the central longitudinal axis.

[0008] Additionally or alternatively, the shaped elements on the side of the gap can cause turbulence in the gas flow in the flame protection device, thereby achieving a higher sealing effect.

[0009] 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. Based on the sheet thickness of the slats, 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 the 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. Based on the sheet thickness of the slat, the minimum gap width when the 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%.

[0010] The gap can also be designed in such a way that when the operating temperature is reached, the thermal expansion of the slats causes the adjacent slats to touch each other at least in some areas, so that the gap is at least partially closed.

[0011] The slats are made of a heat-resistant material, in particular an austenitic chromium-nickel steel, specifically with the material number 1.4841 according to DIN EN 10095. This material has a thermal expansion coefficient α between 15×10 -6< and 20×10 -6< , in particular between 17×10 -6< and 18×10 -6< , in the relevant temperature range. The dimensioning of the gap for the peripheral gap seal depends in particular on the material used for the slats. Other chromium-nickel steels are also possible, in particular 1.4828 or 1.4742, which is known under the trade name Sicromal 10.

[0012] The flame protection device improves the thermal conditions and in particular the gas flow conditions during a combustion process. Thermally heated air is reliably contained within the flame protection device and cannot escape even through the gaps between the lamellae. The combustion process is more efficient. Heat losses are reduced. The fact that the lamellae seal each other prevents material to be dried from accidentally falling into the flame. Flame disturbances that could reduce the efficiency of the combustion process are reliably excluded. The flame protection device enables more efficient combustion. The emission of undesirable exhaust gases, in particular the proportion of unburned hydrocarbons (C tot ), especially carbon monoxide (CO) and / or carbon dioxide (CO 2 ), is reduced. The process is ecologically and economically improved.The combustion process is more sustainable.

[0013] The slats are arranged in particular parallel to the central longitudinal axis of the flame retardant device.

[0014] The flame protection device is used for a burner that generates, in particular, an open burner flame. The burner can be operated with fossil fuels, in particular fossil energy sources such as natural gas, liquefied petroleum gas, heating oil, and / or coal dust. 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.

[0015] The burner is used primarily to heat a drying drum, which is used primarily for heating material in an asphalt plant. The flame protection device in such a drying drum allows for increased addition of recycled material, particularly old asphalt granulate. This makes asphalt production more sustainable because the use of raw materials is reduced.

[0016] The flame protection device ensures uncomplicated and robust installation in the drying drum. In particular, it eliminates the need for a flame tube and a finned recuperator. The flame protection device according to the invention enables functional integration. The number of installed components is reduced. The flame protection device is designed to be simple and cost-effective.

[0017] In particular, it was recognized that it is not necessary for the fins to overlap circumferentially and / or axially. In particular, the manufacture of the fins and, in particular, their arrangement into a flame protection device is simplified.

[0018] A flame protection device according to claim 2 enables a simple and efficient design of the gap seal. The adjacent slats each have sealing elements that correspond to one another. The sealing elements are arranged, in particular, laterally on the slats. 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 peripheral 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.

[0019] A flame protection device according to claim 3 enables a simple and efficient design of the sealing elements on the slats. The production of the slats with the sealing elements is simplified. The sealing elements are designed, in particular, as bevels. The sealing elements can extend along the entire length of the slats. The sealing elements can be designed with interrupted sections, at least in sections, in particular to simplify the production of the sealing elements. The slats have increased rigidity. The risk of undesirable deformation of the slats due to thermal stress is reduced and, in particular, eliminated.

[0020] Alternatively, it is conceivable to attach the sealing elements, in particular as preformed, in particular strip-like shaped elements, to the slats, in particular by welding and / or detachably attaching them, in particular by screwing them.

[0021] Slats according to claim 4 are particularly easy to manufacture. The slats each have a flame-protection section, which is particularly rectangular in design. The sealing elements, in particular, are laterally adjacent to the flame-protection section. The slats can be manufactured from a sheet metal blank, in particular by forming the bevels.

[0022] A flame protection device according to claim 5 has static advantages, particularly during assembly of the flame protection device. The fastening of the flame protection device, for example, in a drying drum, is simplified. It was particularly recognized that the circumferential gap seal simplifies the self-supporting function of the circumferential arrangement. Since adjacent lamellae on the circumferential gap seal engage behind one another at least in sections and in particular linearly, in particular in the radial direction, in particular alternating in the circumferential direction, no additional shaped elements are required.

[0023] A slat holder according to claim 6 ensures simplified assembly. In particular, the slats are placed and / or clipped onto the slat holder. The slats are, in particular, detachably attached to the slat holder. Due to the advantageous attachment of the slat holder to the slat, maximum deformation of the slat due to thermal expansion is reduced. In particular, the deformation of the slat is reduced by more than half compared to a slat according to DE 10 2017 212 046 A1 and, in particular, to a maximum of 40% of the deformation of such a slat. In particular, the slat is provided with several slat holders, in particular exactly two slat holders per slat.

[0024] Alternatively, it is possible to connect the slats firmly and, in particular, non-detachably to the associated slat holders; in particular, the slat holders are welded to the slats. It is advantageous if the contact area between the slat holder and the slat is minimized. In particular, the slat holder is arranged with its end face on an outer side of the slat. A substantially linear contact surface is formed between the slat holder and the slat, which is oriented, in particular, in the circumferential direction and, in particular, perpendicular to the central longitudinal axis.

[0025] For the assembly of the flame protection device, it is advantageous if the individual slats are attached one after the other in the circumferential direction to the respective slat holders. The slats are placed on the slat holders. To fix their position, recesses, in particular punched holes, can be provided on the outer sides of the slats. The slat holders can engage in the recesses or punched holes with corresponding projections. To complete the circumferential arrangement, the last slat of the circumferential arrangement is inserted axially between two adjacent slats. This inserted slat is also referred to as the end slat. The end slat is held by an end slat holder, which differs in design from the other slat holders.The end slat holder does not have any radially protruding projections attached to the end face of the slat holder that engage with the corresponding recesses and / or openings. Instead, the end slat holder has a curved support section to which the end slats are connected, in particular welded, to the end slat holder, in particular by means of plug welding.

[0026] A flame protection device according to claim 7 is designed in a modular manner. In particular, it is possible for the individual lamellae to be compact and their length adapted to the manufacturing process. By arranging several lamellae in succession, the axial extent of the flame protection device can be easily extended. The flame protection device can be easily adapted to the expected length of the burner flame.

[0027] In particular, an axial gap seal can be formed between circumferential arrangements arranged one behind the other.

[0028] Lamellas according to claim 8 enable an uncomplicated design of the axial gap seal.

[0029] A chamfer oriented transversely to the central longitudinal axis enables an advantageous design of the axial gap seal. The lamella is additionally stabilized and offers increased rigidity.

[0030] A slat according to claim 9 enables the advantages of the flame protection device itself.

[0031] A drying drum according to claim 10 enables the advantageous implementation of the combustion process with increased efficiency and / or reduced exhaust emissions. In particular, the drying drum enables the use of increased amounts of reclaimed asphalt granulate in asphalt production.

[0032] Both the features specified in the patent claims and the features specified in the following exemplary embodiments of the flame protection device according to the invention are suitable, either 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 limitation with regard to further developments of the subject matter of the invention, but are essentially merely exemplary in nature.

[0033] Further advantageous embodiments, additional features, and details of the invention will become apparent from the following description of an embodiment with reference to the drawings. They show: Fig. 1 is 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 is 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 a front end 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 view of a lamella according to Fig. 8 .

[0034] One in Fig. 1 The arrangement, designated as a whole by 1, comprises a drying drum 2, on the front of which a burner 3 is arranged. The arrangement 1 is, in particular, part of an asphalt plant in which asphalt material is produced.

[0035] In the drying drum 2, white mineral, in particular, is heated using a countercurrent process. This means that a material flow direction 4 and a heat propagation direction 5 are oriented opposite to each other. The drying drum 2 can also be operated using a cocurrent process. In particular, other materials, especially rock and / or old asphalt material, can also be heated in the drying drum 2.

[0036] The burner 3 generates a burner flame 6 which extends at least partially into the drying drum 2.

[0037] A flame protection device is arranged in the drying drum 2, particularly in the area of ​​the burner flame 6. The flame protection device has a central longitudinal axis 7, which coincides with a rotational axis 8 of the drying drum 2.

[0038] The flame protection device has a plurality of fins 9 arranged in the circumferential direction 10 relative to the central longitudinal axis 7. The fins 9 ensure that thermally heated air remains within the circumferential arrangement 10 and does not inadvertently flow outward, particularly in the radial direction relative to the central longitudinal axis 7. The fins 9 prevent material heated in the drying drum 2 from inadvertently falling into the burner flame 6 and thus adversely affecting the combustion process.

[0039] The flame protection device has throwing plates 11. The throwing plates 11 are arranged concentrically with respect to the central longitudinal axis 7, in particular with respect to the slats 9 in the drying drum 2. The throwing plates 11 are arranged in the flame region of the drying drum 2. The throwing plates 11 enable the material to be dried to be entrained when the drying drum 2 rotates, i.e., material to be conveyed along the material conveying direction 4. The throwing plates 11 are designed in particular such that a material curtain in the drying drum 2 is prevented when the material is entrained. This means that when the drying drum 2 rotates about the axis of rotation 8, the material is held in the radial direction in the throwing plates 11 and, in particular, only axial material conveyance along the material conveying direction 4 occurs.In particular, the throwing plates 11 reliably prevent the material from trickling from top to bottom in the drying drum 2 due to gravity and forming a material veil.

[0040] By entraining 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. The material thus cools the internals and the drying drum 2.

[0041] Slat holders 12 are attached to the throwing plates 11 and serve to hold the slats 9. The slat holders 12 are attached to the throwing plates 11. The slat holders 12 extend, in particular, perpendicular to the central longitudinal axis 7 and, in particular, radially.

[0042] The flame protection device has a baffle 13. The baffle 13 is arranged along the central longitudinal axis 7 at an axial distance from the slats 9. The baffle 13 is disc-shaped and, in particular, substantially circular, and is fastened in the drying drum 2 with at least one baffle fastening element 14. The baffle 13 prevents the burner flame 6 from inadvertently penetrating another baffle area of ​​the drying drum 2 located behind the baffle 13. A material veil is deliberately created in this additional baffle area. The baffle 13 prevents material damage.

[0043] The following is based on Fig. 2 bis Fig. 9 the flame protection device is explained in more detail.

[0044] A circumferential arrangement of slats 9 comprises eighteen individual slats 9. The slats 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 slats 9 can be used to form a circumferential arrangement.

[0045] According to the illustrated embodiment, four circumferential arrangements are arranged one behind the other along the central longitudinal axis 7. More or fewer than four circumferential arrangements can also be arranged one behind the other. The individual circumferential arrangements are, in particular, identical in design. It is also conceivable for the circumferential arrangements to have different diameters and / or to be conical in design, at least in sections.

[0046] The slats 9 each have a flame protection section 15 facing inwards, i.e. towards the burner flame 6. The flame protection section 15 has a rectangular contour with a length L and a width B. According to the exemplary embodiment shown, the length L of the slat 9 is greater than its width B. In particular, L >= 1.2 × B, in particular L > = 1.5 × B, in particular L > = 2.0 × B, in particular L > = 2.5 × B and in particular L < = 10 × B. The slats 9 are arranged next to one another in the circumferential arrangement with regard to their longitudinal direction. In the circumferential arrangement, the slats 9 are oriented with their longitudinal direction parallel to the central longitudinal axis 7. This means that a contour formed by the slats 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 flat, the peripheral arrangement has an inner contour in a plane perpendicular to the central longitudinal axis 7 which is essentially polygonal.

[0047] The slats 9 are made of sheet metal with the material number 1.4841. The sheet thickness s is in particular in a range from 3 mm to 10 mm, and in particular between 5 mm and 7 mm.

[0048] The slat 9 has integrally formed sealing elements 16, 17 on its longitudinal edges. The sealing elements 16, 17 are designed as bevels. The sealing elements 16, 17 are designed to correspond to one another. The sealing elements 16, 17 form lateral sealing elements on the slats 9. The sealing elements 16, 17 form sealing strips. The sealing elements 16, 17 are designed such that the slats 9 are arranged alternately with the sealing elements 16, 17 in the circumferential order.

[0049] A first sealing element 16 essentially has an S-shaped contour. The S-shaped contour extends, in particular, from the flame protection section 15 in a direction away from the burner flame 6. The first sealing element 16 forms a concave receptacle.

[0050] The second sealing element 17 has a contour corresponding to a rounded arrowhead. The second sealing element 17 forms a convex projection.

[0051] 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 lamellas 9 with the sealing elements 16, 17 arranged one inside the other is particularly Fig. 4 and 6Corresponding 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 × s, in particular at most 0.3 × s, in particular at most 0.2 × s and in particular 0.1 × s.

[0052] Due to this thin gap between the adjacent lamellae 9, a circumferential gap seal is formed. Due to the thermal expansion of the lamellae 9 during operation of the drying drum 2, the gap width continues to decrease.

[0053] Because the lamellae 9 of a circumferential arrangement interlock with the adjacent sealing elements 16, 17, the circumferential arrangement is designed to be self-supporting. This prevents the lamellae 9 from accidentally separating from one another. The sealing elements 16, 17 engage the adjacent lamellae 9 behind one another in such a way that the circumferential arrangement is designed to be stable in the radial direction relative to the central longitudinal axis 7.

[0054] On a transverse edge oriented in the width direction, the slats 9 have a front bevel 18. The front bevel 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 bevel 18 functions as an insertion tab, which can be inserted, in particular, into the respective peripheral arrangement arranged in front of it.

[0055] If several circumferential arrangements are arranged one behind the other along the central longitudinal axis 7, the slats 9 of the respective rear circumferential arrangement are pushed with the bevel 18 under the respective slat 9 of the preceding circumferential arrangement. This means that the bevel 18 is arranged on the inner side of the circumferential arrangement facing the burner flame 6. The bevel 18 forms an axial gap seal between the circumferential arrangements arranged one behind the other along the central longitudinal axis 7. The tightness of the circumferential arrangements is high.

[0056] The slats 9 arranged one behind the other along the central longitudinal axis 7 are aligned.

[0057] Each slat 9 is held by at least one slat holder 19, and according to the illustrated embodiment, by two slat holders 19. The slat holder 19 is made from a flat sheet metal blank and, in particular, has a strip-like contour. The slat holder 19 is, in particular, made from the same material as the slat 9. The sheet thickness of the slat holder is, in particular, between 8 mm and 15 mm and, in particular, between 10 mm and 12 mm.

[0058] According to the exemplary embodiment shown, the slat holder 19 has projections, in particular two retaining pins, which are arranged in particular on the end face. The retaining pins can engage in recesses 20 arranged on the flame protection section 15. The recesses 20 are designed in particular as punched-through holes. The slat 9 is in particular supported or placed on the slat holder 19. The recesses 20 serve as an assembly aid for the slat holder 19 of the slat 9. In particular, the slat 9 is detachably fastened to the slat holder 19. This simplifies the assembly of the peripheral arrangement. Additionally or alternatively, the slat holders 19 can also be permanently fastened to the slat 9, in particular by welding.

[0059] At least one slat 31 per circumferential arrangement is designed differently with respect to the recesses 20. This slat is referred to as the end slat 31. Accordingly, the associated end slat holders 32 for the end slat 31 do not have any protruding retaining pins, but rather a bent support tab 21, which is particularly Fig. 5 is shown.

[0060] The circumferential arrangement is formed by arranging slats 9 adjacent to one another in the circumferential direction 10 and placing them on the respective slat holders 19. The slats 19 are stabilized by the interlocking sealing elements 16, 17 on the one hand and by the engagement of the retaining pins in the recesses 20 on the other. The final slat, the closing slat 31, is inserted axially, i.e. in a direction parallel to the central longitudinal axis 7, and in doing so comes into engagement with the two adjacent slats 9. The sealing elements 16, 17 ensure an undercut in the radial direction between adjacent slats 9 and 9, 31. The last-mounted closing slat 31 is fastened, in particular welded, to the support lugs 21.

[0061] The use of the slat holders 19 makes it possible for the slats 9 to be arranged in the drying drum 2 at a radial distance from an inner wall 22 of the drying drum 2. The slats 9 form an installation spaced from the inner wall 22 and aligned concentrically with the central longitudinal axis 7. The peripheral arrangement is essentially ring-shaped with a polygonal inner contour. The peripheral arrangement is firmly connected to the drying drum 2. When the drying drum 2 rotates, the peripheral arrangement rotates with it.

[0062] With respect to the slats 9, the throwing plates 11 are arranged radially offset outward in the radial direction relative to the rotation axis 8. In particular, the throwing plates 11 are arranged on the inner wall 22 of the drying drum 2.

[0063] For this purpose, retaining tabs 23 can be attached, in particular welded, directly to the inner wall 22. A fastening strip 24 is releasably attached, in particular screwed, to each of the retaining tabs 23. In particular, each throwing plate 11 is held by several, in particular three, fastening strips 24, wherein the fastening strips 24 are identical and arranged at a distance from one another along the central longitudinal axis 7.

[0064] The fastening strips 24 each have a slot-shaped receptacle 25 into which the throwing plates 11 are inserted.

[0065] The throwing plate 11 is designed like a scoop 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 web of the "L" extends essentially parallel to the inner wall 22 of the drying drum 2. "Substantially" means that the throwing plate 11 has no curvature on the inner wall 22 of the drying drum 2. To increase rigidity, the throwing plate 11 can be designed with bevels. 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 a side opposite the short web of the "L". The material receiving chamber is also open, in particular, along the central longitudinal axis 7.It is possible for these end faces of the material receiving chamber to be 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, in particular welded, to the throwing plate 11.

[0066] The throwing plates 11, arranged one behind the other along the central longitudinal axis 7, are thus arranged continuously with respect to one another, i.e., they abut one another at the end. The throwing plates 11 form the material intake channel extending over several throwing plates 11.

[0067] 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 veil is formed in the area of ​​the slats 9.

[0068] The short web of the "L" forms a rear wall 27 of the throwing plate 11. The slat holders 19 of the slats 9 are releasably attached to the rear wall 27. According to the illustrated embodiment, a retaining bracket 28 is used for this purpose, which is designed in particular as an L-shaped profile and enables screwing of sheet metal sections oriented at 90° to each other.

[0069] A particularly advantageous feature is that the louvre holders 19 are detachably attached to the deflector plates 11. Retrofitting the louvre holders 19 and / or the louvres 9 held thereon is simplified. In particular, it is no longer necessary for the louvres 9 to be attached to the interior wall itself using the louvre holders 19. The assembly and disassembly effort is reduced.

[0070] In particular, at least one throwing plate 11 is provided for each lamella 9. Corresponding lamellas 9 and throwing plates 11 are arranged in radial alignment with respect to the central longitudinal axis 7.

[0071] According to the illustrated embodiment, in addition to the four throwing plate arrangements arranged concentrically to the respective circumferential arrangements of the slats 9, two further rows of throwing plates 11 are provided. No slats 9 are attached to these throwing plates 11. These throwing plates are therefore arranged in an exposed position.

[0072] The baffle wall 13 is arranged axially spaced from the slats 9, which is particularly Fig. 3is shown. The baffle 13 is constructed from several identical baffle segments 29, three according to the illustrated embodiment. The baffle segments 29 each have a disc section and a baffle fastening element 14 attached thereto in one piece. The disc sections are each designed like a third of a circular disc, i.e., with an opening angle of 120° relative to the central longitudinal axis 7. To connect the baffle segments 29, flange strips are folded onto the parallel wall segments 29 and screwed together. The baffle segments 29 are attached to corresponding throw plates 11 by means of the baffle fastening elements 14 and by means of a retaining tab 30 provided for this purpose.

Claims

1. Flame protection device for a burner (3), in particular in a drying drum (2), in particular of an asphalt plant, wherein the flame protection device has a central longitudinal axis (7) and a plurality of lamellae (9, 31) which are arranged in a circumferential arrangement in the circumferential direction (10) with respect to the central longitudinal axis (7), wherein lamellae (9, 31) arranged adjacent to one another in the circumferential direction (10) are sealed by means of a circumferential gap seal.

2. Flame protection device according to claim 1, characterized in that Lamellae (9, 31) arranged adjacently in the circumferential direction (10) have sealing elements (16, 17) facing one another, in particular sealing strips.

3. Flame protection device according to claim 2, characterized in that the sealing elements (16, 17) are formed in one piece and are designed in particular as bevels of the slats (9, 31).

4. Flame protection device according to one of the preceding claims, characterized in thatthe slats (9, 31) have a flame protection section (15) pointing towards the central longitudinal axis (7) which is flat.

5. Flame protection device according to one of the preceding claims, characterized in that the circumferential arrangement of the slats (9, 31) is self-supporting.

6. Flame protection device according to one of the preceding claims, characterized by at least one slat holder (12, 32) which is fastened to a slat (9, 31).

7. Flame protection device according to one of the preceding claims, characterized in that several circumferential arrangements are arranged one behind the other along the central longitudinal axis (7), wherein an axial gap seal is formed in particular between lamellae (9, 31) which are arranged adjacently along the central longitudinal axis (7).

8. Flame protection device according to one of the preceding claims, characterized in thatthe slats (9, 31) have a bevel (18) on a transverse edge oriented transversely, in particular vertically, with respect to the central longitudinal axis (7).

9. A slat for a flame protection device according to any one of the preceding claims.

10. Drying drum with a flame protection device according to one of the preceding claims.

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