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 (41) for a burner (3) is arranged in a drying drum (2) and has a central longitudinal axis (7) and several lamellae (9) which are arranged in a circumferential arrangement (40) in the circumferential direction (10) with respect to the central longitudinal axis (7), wherein an outer surface (42) of the circumferential arrangement (40) facing away from the central longitudinal axis (7) is formed without radial projections.

Description

[0001] The content of the German patent application DE 10 2024 209 335.1 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] EP 2 281 945 B1 discloses a drying drum for plants producing bituminous mixtures. The drying drum incorporates a shielding structure to protect the material being heated from the burner flame. This shielding structure has recesses for receiving the material. When bituminous mixtures, particularly reclaimed asphalt, are heated, agglomerates can form and clump together in these recesses. This reduces heat transfer from the shielding structure to the material being heated, resulting in the loss of the clumped material. The shielding structure then requires maintenance or replacement.

[0004] DE 10 2022 211 106 B4 discloses a flame guard device for a burner. To prevent material accumulation, the lamellae of the flame guard device are flat, i.e., without indentations.

[0005] The invention is based on the objective of improving the drying process in a drying drum, in particular avoiding agglomerations of the material to be heated and / or sticking of the material to be heated to the flame protection device.

[0006] This problem is solved by a flame protection device having the features of claim 1, by a lamella having the features of claim 9 and by a drying drum having the features of claim 10.

[0007] The core of the invention consists in a flame guard device having a central longitudinal axis and several louvers, designed without radial projections on its outer surface. The flame guard device is designed without any radial projections to the outside, i.e., in a direction away from the central longitudinal axis. The louvers are made of metal sheets, particularly with a substantially rectangular shape. The louvers are arranged circumferentially with respect to the central longitudinal axis. The flame guard device is formed by the louvers in this circumferential arrangement. The circumferential arrangement is tubular in design. The circumferential arrangement is arranged concentrically within the drying drum with respect to the axis of rotation of the drying drum.An annular space is formed between the outside of the circumferential arrangement and the inside of the drying drum, in which the material to be heated is conveyed axially through the drying drum.

[0008] The contour of the flame protection device perpendicular to the central longitudinal axis is constant along the central longitudinal axis. In particular, at least four, in particular at least six, in particular at least eight, in particular at least 10, in particular at least 12, in particular at least 14, in particular at least 16, in particular at least 18 or more louvers are present in the circumferential arrangement. In a plane perpendicular to the central longitudinal axis, the outer surface of the circumferential arrangement is polygonal.

[0009] The absence of a radial projection on the outer surface allows for efficient material conveyance within the drying drum. In particular, it has been found that heat transfer from the flame guard to the material being heated, which is conveyed in the annular space between the flame guard and the drying drum, is facilitated. The heat generated by the burner is transferred directly to the flame guard and can then be advantageously transferred from the flame guard into the annular space to the material being heated. Disruptive material buildup on the outer surface of the flame guard is reliably prevented.

[0010] The flame protection device, in particular the drying drum, is primarily intended for use in an asphalt plant. The material to be heated in the drying drum is, for example, rock, especially white minerals. Additionally or alternatively, the drying drum can also be used to heat reclaimed asphalt, so-called recycled asphalt.

[0011] 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.

[0012] 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.

[0013] A louver holder attached to a louver ensures simplified installation. Specifically, the louvers are placed on and / or clipped onto the louver holder. The louvers are detachably attached to the louver holder. This 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 as defined in DE 10 2017 212 046 A1, and especially to a maximum of 40% of the deformation of such a louver. In particular, several louver holders are present per louver, specifically exactly two louver holders per louver.

[0014] 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.

[0015] 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.

[0016] A flame guard in which several circumferential assemblies are arranged one behind the other along the central longitudinal axis is modular in design. In particular, the individual lamellae can be designed to be small and their length adapted to the manufacturing process. The axial extent of the flame guard can be easily extended by arranging several circumferential assemblies in succession. The flame guard can thus be easily adapted to the expected length of the burner flame.

[0017] In particular, an axial gap seal can be formed between circumferential arrangements arranged one behind the other.

[0018] The lamellae can have a chamfer on a transverse edge oriented transversely to the central longitudinal axis, enabling a straightforward design of the axial gap seal.

[0019] 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. The bend is oriented radially inwards towards the central longitudinal axis. This prevents a radial projection on the outside of the flame protection device.

[0020] A seal for the lamellae according to claim 2 enables a reliable and simple seal of the circumferential arrangement. It was particularly recognized that the circumferential gap seal allows for thermally induced expansion of the lamellae. The operation of the flame protection device is ensured within the expected temperature range.

[0021] This is based on the finding 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.

[0022] The circumferential gap seal, also known as a labyrinth seal, is a non-contact seal. Its sealing effect is based on lengthening the flow path through the gap to be sealed, thereby significantly increasing flow resistance. This path lengthening is achieved primarily through the interlocking of the adjacent lamellae. Additionally or alternatively, the lateral elements of the seal can create turbulence in the gas flow within the flame arrestor, resulting in a higher degree of sealing.

[0023] 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%.

[0024] 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.

[0025] 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.

[0026] In particular, the sealing gap is designed with a constant gap width.

[0027] A flame protection device according to claim 3 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.

[0028] In particular, the corresponding sealing elements of adjacent lamellae have a corresponding geometry. The sealing elements are formed, in particular, on the opposite longitudinal edges of the lamellae. The corresponding sealing elements have different geometries. In particular, two different types of sealing elements are present. It is advantageous to form one type of sealing element on each lamella. The flame protection device can advantageously be formed from a plurality of identically designed lamellae. Alternatively, it is also conceivable to form two identical sealing elements on each lamella, so that different types of lamellae are formed. In this case, the different types of lamellae are arranged alternately in the circumferential direction of the flame protection device.

[0029] A flame protection device according to claim 4 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 designed, in particular, as folded edges. 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.

[0030] 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.

[0031] A flame-resistant device according to claim 5 provides the advantageous circumferential gap seal, wherein the outer surface of the circumferential arrangement is free of protrusions. The sealing elements extend, particularly in the radial direction with respect to the central longitudinal axis, towards the central longitudinal axis. This is based on the understanding that even small radial protrusions that may be formed by the sealing elements can lead to undesirable material accumulation and thus to adhesion on the outer surface of the drying drum. This adhesion is undesirable and can be reliably prevented by the radially inwardly directed sealing elements.

[0032] A flame protection device according to claim 6 enables an improved sealing effect. In particular, the sealing elements have an L- or S-shaped geometry in a plane perpendicular to the central longitudinal axis. Because the sealing elements of the lamellae are designed at least partially and, in particular, linearly, the flow path through the gap seal is increased, thus improving the sealing effect.

[0033] The louvers according to claim 7 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.

[0034] The flame protection section is therefore arranged circumferentially with respect to the central longitudinal axis between the two sealing elements. In particular, the sealing elements connect directly to the flame protection section. The flame protection section is bounded by the sealing elements.

[0035] A flame guard according to claim 8 offers static advantages, particularly with regard to the assembly of the flame guard. For example, the fastening of the flame guard 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 lamellae on the circumferential gap seal interlock with each other, at least sectionally and especially linearly, particularly in the radial direction, and alternately in the circumferential direction, no additional molded elements are required.

[0036] A lamella according to claim 9 enables the advantages of the flame protection device itself.

[0037] A drying drum according to claim 10 enables the advantageous execution of the combustion process with increased efficiency and / or reduced exhaust emissions. In particular, the drying drum allows the use of increased asphalt granulate proportions in asphalt production.

[0038] Both the features specified in the claims and those specified in the following exemplary 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 constitute a limitation with regard to further developments of the subject matter of the invention, but are essentially merely exemplary.

[0039] 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 an enlarged partial sectional view of a specific embodiment of the drying drum according to section line II-II in Fig. 1 , Fig. 3 a perspective view of a lamella according to Fig. 2 .

[0040] 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.

[0041] 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.

[0042] The burner 3 generates a burner flame 6, which extends at least partially into the drying drum 2.

[0043] A flame guard 41 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.

[0044] The flame guard 41 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 40 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.

[0045] The flame protection device 41 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 takes place.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.

[0046] 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.

[0047] The blade plates 11 are fitted with lamella holders 19, which serve to hold the lamellae 9. The lamella holders 19 are attached to the blade plates 11. The lamella holders 19 extend, in particular, perpendicular to the central longitudinal axis 7 and, in particular, radially.

[0048] The flame protection device 41 has 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.

[0049] The following will be based on Fig. 2 and 3 The flame protection device 41 is explained in more detail.

[0050] The drying drum 2 in question, as well as the basic structure and function of the flame protection device 41, are described in DE 10 2022 211 106 B4, to which explicit reference is hereby made.

[0051] The circumferential arrangement 40 comprises eighteen louvers 9. The louvers 9 are functionally identical and, in particular, have identical dimensions. The louvers 9 are designed as so-called identical parts and can be manufactured efficiently. Depending on the required size of the flame guard 41, in particular the clear width of the circumferential arrangement 40, more or fewer louvers 9 can also be used.

[0052] Along the central longitudinal axis 7, four circumferential assemblies 40 are arranged one behind the other according to the illustrated embodiment. More or fewer than four circumferential assemblies 40 can also be arranged one behind the other. The individual circumferential assemblies 40 are preferably identical. It is also conceivable that the circumferential assemblies 40 have different diameters and / or are at least partially conical.

[0053] 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 40 with respect to their longitudinal direction. In the circumferential arrangement 40, 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 40 has an inner contour in a plane perpendicular to the central longitudinal axis 7, which is essentially polygonal.

[0054] 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.

[0055] The lamella 9 has sealing elements 16, 17 integrally molded onto its longitudinal edges. The sealing elements 16, 17 are designed as folded edges. The sealing elements 16, 17 are designed to correspond to each other.

[0056] The sealing elements 16, 17 form lateral sealing elements on the lamellae 9. The sealing elements 16, 17 form sealing strips. The sealing elements 16, 17 are designed such that the lamellae 9 are arranged alternately with the sealing elements 16, 17 in the circumferential order 40.

[0057] The first sealing element 16 essentially has an S-shaped contour. The first sealing element 16 extends, in particular, from the flame protection section 15 in a direction towards the central longitudinal axis 7, i.e., radially inwards. The first sealing element 16 forms a concave recess. The first sealing element 16 constitutes a first type of sealing element.

[0058] The second sealing element 17 has a contour corresponding to a rounded arrowhead. The contour is, in particular, L-shaped. The second sealing element 17 forms a convex projection. The second sealing element 17 extends, in particular, from the flame-resistant section 15 in a direction towards the central longitudinal axis 7, i.e., radially inwards. The second sealing element 17 constitutes a second type of sealing element.

[0059] Because the sealing elements 16, 17 extend radially inwards with respect to the central longitudinal axis 7, an outer surface 42 of the circumferential arrangement 40 is free of radial projections. Material heating is improved. The risk of undesirable material adhesion and / or agglomeration is avoided.

[0060] 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. 2The corresponding sealing elements 16, 17 of adjacent lamellae 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.

[0061] 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.

[0062] Because the lamellae 9 of a circumferential arrangement 40 interlock with their respective adjacent sealing elements 16, 17, the circumferential arrangement 40 is self-supporting. This prevents the lamellae 9 from unintentionally separating from one another. The sealing elements 16, 17 cause the adjacent lamellae 9 to interlock in such a way that the circumferential arrangement 40 is stable in the radial direction with respect to the central longitudinal axis 7.

[0063] The lamellae 9 have a front flange 18 at a transverse edge oriented in the width direction. The front flange 18 is inclined upwards 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 arranged in front of it.

[0064] When several circumferential assemblies 40 are arranged one behind the other along the central longitudinal axis 7, the lamellae 9 of the rearmost circumferential assembly 40 are pushed over the respective lamella 9 of the circumferential assembly 40 arranged 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 40 facing the burner flame 6. The bend 18 forms an axial gap seal between the circumferential assemblies 40 arranged one behind the other along the central longitudinal axis 7. The circumferential assemblies have a high degree of tightness.

[0065] The lamellae 9 arranged one behind the other along the central longitudinal axis 7 are aligned.

[0066] 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.

[0067] 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.

[0068] At least one lamella 31 in each circumferential arrangement has a different design with respect to the recesses 20. This lamella is referred to as the end lamella. Accordingly, the associated end lamella holders for the end lamella do not have protruding retaining pins, but rather a bent-over support tab.

[0069] The circumferential arrangement 40 is formed by arranging lamellae 9 adjacent to one another in a row along the 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 final lamella, the end lamella, 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. The last lamella to be installed is attached to the support lugs 21, in particular by welding.

[0070] By using the lamella holders 19, the lamellae 9 can be arranged in the drying drum 2 with a radial spacing relative to 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 40 is essentially ring-shaped with a polygonal inner contour. The circumferential arrangement 40 is rigidly connected to the drying drum 2. When the drying drum 2 rotates, the circumferential arrangement 40 rotates with it.

[0071] 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.

[0072] 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.

[0073] The mounting strips 24 each have a slot-shaped receptacle 25 into which the throwing plates 11 are inserted.

[0074] 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 26 is formed between the throwing plate 11 and the inner wall 22 of the drying drum 2. This chamber 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 26 is also open along the central longitudinal axis 7.It is possible that these end faces of the material receiving chamber 26 are closed by separate cover elements not shown. In particular, the end face of the material receiving chamber 26 facing the material outlet of the drying drum 2 is closed by the cover element. The cover element is attached to the deflector plate 11, in particular by welding.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

Claims

1. Flame guard for a burner (3), wherein the flame guard (41) is arranged in a drying drum (2), wherein the flame guard (41) has a central longitudinal axis (7) and several lamellae (9) arranged in a circumferential arrangement (40) in the circumferential direction (10) with respect to the central longitudinal axis (7), characterized by the fact that one outer side (42) of the circumferential arrangement (40) facing away from the central longitudinal axis (7) is formed without radial projections.

2. Flame protection device according to claim 1, characterized by the fact that The lamellae (9) arranged adjacent in the circumferential direction (10) are sealed by means of a circumferential gap seal.

3. Flame protection device according to one of the preceding claims, characterized by the fact that the lamellae (9) arranged adjacent in the circumferential direction (10) have sealing elements (16, 17) facing each other.

4. Flame protection device according to claim 3, characterized by the fact thatthe sealing elements (16, 17) are each integrally formed on the lamellae (9) and are designed in particular as bends of the lamellae (9).

5. Flame protection device according to claim 3 or 4, characterized by the fact that the sealing elements (16, 17) extend from the lamella (9) towards the central longitudinal axis (7).

6. Flame protection device according to one of claims 3 to 5, characterized by the fact that the sealing elements (16, 17) are non-linear in a plane perpendicular to the central longitudinal axis (7).

7. Flame protection device according to one of the preceding claims, characterized by the fact that the lamellae (9) have a flame protection section (15) pointing towards the central longitudinal axis (7), which is designed to be flat.

8. Flame protection device according to one of the preceding claims, characterized by the fact that the circumferential arrangement (40) of the lamellae (9) is designed to be self-supporting.

9. Lamella for a flame protection device (41) according to one of the preceding claims.

10. Drying drum with a flame protection device (41) according to any one of claims 1 to 8.

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