FIRE PROTECTION FLAP FOR A FLOW- TUB

Description

[0001] The invention relates to a fire damper for a through-flow air duct, comprising a through-opening, a closure element, a guide system, a drive element and a holding element, wherein the closure element can be brought into an open position and a closed position and wherein in the closed position of the closure element an outer contour of the closure element encloses an inner contour of the through-opening and thus the closure element covers the through-opening and wherein the closure element in its open position releases the through-opening and the holding element fixes the closure element in the open position and wherein the holding element is designed to release the closure element in the event of fire and wherein the guide system is designed to guide the closure element in the direction of the through-opening driven by a closing force provided by the drive element.

[0002] To supply fresh air to the rooms of a building, a system of ventilation ducts is provided. This system of ventilation ducts carries fresh air from the building's surroundings into the rooms (supply air duct) and stale air from the rooms to the building's surroundings (exhaust air duct). The airflow in the ventilation ducts is typically driven by one or more fans.

[0003] At least some of the rooms in the building are connected via the ventilation duct system. For fire safety reasons, it is necessary that in the event of a fire in one of the rooms, the supply and exhaust air ducts for that room be closed. This prevents the fire from spreading to other rooms via the ventilation ducts and prevents smoke gases from being conducted into other rooms via the ventilation ducts.

[0004] Fire dampers are typically used to close ventilation ducts. These are integrated into the respective ventilation duct, and the ventilation duct is closed by the fire damper in the event of a fire.

[0005] Various solutions for fire dampers are described in the prior art. DE 28 54 267 A1 discloses a fire damper featuring a closure element designed as a drop flap, guided by two rails. When open, the drop flap is held above the ventilation duct by a fusible link, thus opening the air flow path in the ventilation duct. In the event of a fire, the fusible link is released due to the temperatures generated during the fire, and the drop flap falls vertically into the ventilation duct, either under gravity or with spring support, closing the air flow path in the ventilation duct.

[0006] A similar fire damper is disclosed in DE 202 02 450 U1. Here, too, a closure element designed as a drop flap is held above the ventilation duct and, in the event of a fire, drops vertically into the ventilation duct to close it. The drop flap is not guided by a rail system, but slides within a layered wall element of the fire damper.

[0007] Further fire dampers can also be found in the state of the art in the documents AT 508 116 A4 and DE 21 23 471 A1.

[0008] However, the known fire damper solutions have proven to be disadvantageous in that the drop flap does not always seal the ventilation duct sufficiently tightly, as the drop flap does not always fit completely flush with the flow duct opening. This means that fire gases, in particular, cannot be reliably contained.

[0009] The object of the invention is to create a fire damper for a ventilation duct that reliably closes the ventilation duct with a closure element in the event of a fire. The closure element should meet the requirements of the relevant standards for a fire resistance test, in particular, according to EN 1366-2, regarding the separation of the passage, insulation, and smoke tightness.

[0010] This object is achieved by a fire damper having the features of claim 1. Advantageous embodiments can be found in subclaims 2 to 5. Furthermore, the object is achieved by a fire damper having the features of claim 6. Advantageous embodiments in this regard can be found in subclaims 7 to 15.

[0011] The fire damper enables the ventilation duct to be closed. For this purpose, the retaining element is released and the closure element is moved toward the passage opening by the guide system and the closing force provided by the drive element, so that the closure element then covers the passage opening in its closed position. In the closed position, a side of the closure element facing the passage opening rests against a side of the first wall element accommodating the passage opening that faces the closure element. According to the invention, the closure element is mounted in a pendulum motion in the guide system. This allows a cross-sectional plane of the closure element to be inclined relative to the cross-sectional plane of the passage opening before assuming the closed position.This has the advantage that the side of the closure element facing the through-opening also rests completely along the through-opening against the side of the first wall element facing the closure element. Furthermore, the guide system is designed such that in the closed position, a force component of the closure force presses a side of the outer contour of the closure element facing the inner contour of the through-opening against a side of the inner contour of the through-opening facing the outer contour of the closure element. In interaction with the pendulum bearing, the force component of the closure force further supports the flush seating of the closure element, since the closure element is pressed against the through-opening by the force component of the closure force.

[0012] Exemplary embodiments of the invention are explained below with reference to the drawings. They show: Fig. 1 an exploded view of an embodiment of a fire damper according to the invention Fig. 2a a perspective view of the fire damper according to Fig. 1 with the locking element in open position Fig. 2b Sectional view of the fire damper according to Fig. 1 with the closure element in open position Fig. 2c a perspective view of the fire damper according to Fig. 1 with the locking element in the locking position Fig. 2 sectional view of the fire damper according to Fig. 1 with the closure element in the closed position Fig. 3a a spatial representation of a further embodiment of the fire damper according to the invention with the closure element in the open position Fig. 3b a spatial representation of the further embodiment according to Fig. 3a with the closure element in the closed position Fig. 3c a spatial representation of another version of the fire damper Fig. 4a a top view of the fire damper according to Fig. 3a with flow channel-forming insert Fig. 4b Top view of the fire damper according to Fig. 3b with flow channel-forming insert Fig. 5the fire damper according to Fig. 3a with flow channel-forming insert

[0013] Fig. 1 shows an exploded view of an embodiment of a fire damper 1 according to the invention for a flow-through air duct. The ventilation duct and the building are not shown. The fire damper 1 has a through-opening 2, a closure element 3, a guide system 4, a drive element 5, and a holding element 6. The fire damper 1 is arranged in the ventilation duct such that the supply or exhaust air guided in the ventilation duct is guided along a flow direction through the through-opening 2. The closure element 3 can be brought into an open position and a closed position, with the illustration showing the closure element 3 in its open position. In this open position, the closure element 3 releases the through-opening 2, so that the flow guided in the ventilation duct can pass through the through-opening 2.In the illustrated embodiment, the closure element 3 is disc-shaped, without the fire damper 1 according to the invention being limited to closure elements 3 designed in this way.

[0014] The through-opening 2 is located in a first wall element 7 of the fire damper 1. Furthermore, the fire damper 1 has a second wall element 8. A further through-opening 9 is provided here for the flow guided in the ventilation duct. The second wall element 8 is arranged at a distance from the first wall element 7 on a side facing the closure element 3.

[0015] The closure element 3 is fixed in the open position by the holding element 6. The holding element 6 is designed such that the closure element 3 is released in the event of a fire. In the illustrated embodiment, the holding element 6 is designed as a fusible link, wherein, in the open position of the closure element 3, this fusible link connects an angle 10a fastened to the second wall element 8 and an angle 10b fastened to the closure element 3. In the event of a fire, the solder of the fusible link melts, causing it to lose its mechanical strength, so that the connection between the angle 10a and the angle 10b is released and the closure element 3 is no longer fixed to the second wall element 8.

[0016] The guide system is designed such that the closure element 3, released from the holding element 6, is pivoted toward the through-opening by a closure force provided by the drive element 5. In the illustrated embodiment, the drive element 5 is designed as a tension spring. The guide system consists of two joints 11, two pendulum bearings 12, and two support elements 4, each with two legs 4a, 4b aligned at an angle to one another. The support elements 4 are each rotatably mounted on the first wall element 7 via the joints 11 at the intersection point 13 of the leg axes. The closure element 3 is fixed at two opposite points to one of the legs 4b of the support elements 4 via the pendulum bearings 12. The drive element 5, designed as a tension spring, connects the other legs 4a of the support elements 4 to angle brackets 14 attached to the second wall element 8.In the open position, the tension spring is tensioned, so that the spring ends (force-transmitting ends of the drive element) transfer the tension force of the tension spring to the legs 4a. Due to the angular alignment of the legs 4a, 4b, this tension force of the tension spring is transferred to the closure element 3, where it acts as a closure force that guides the closure element 3 toward the through-opening 2 when the retaining element 6 is released.

[0017] A space spanned between the first and second wall elements 7, 8 is surrounded by a sleeve element 15 of the fire damper 1. Fastening elements 16a, 16b are provided on this sleeve element 15 for positively anchoring the sleeve element in a building wall or building ceiling. The fastening element 16a is designed as a mortar tab, and the fastening element 16b as an eyelet for receiving a fastening screw (not shown). The first wall element, the second wall element 8, and the sleeve element 15 together form an air-conducting housing of the fire damper 1 according to the invention, which encloses an air-conducting space.

[0018] Fig. 2a shows a perspective view of the fire damper 1 according to Fig. 1 without sleeve element 15 and second wall element 8. The closure element 3 is located as in Fig. 1 in its open position.

[0019] Fig. 2b shows a sectional view of the fire damper 1 according to Fig. 1 with the locking element 3 in the open position.

[0020] In Fig. 2c is a perspective view of the fire damper 1 according to Fig. 1 without sleeve element 15 and second wall element 8. Here, the closure element 3 is in its closed position. The closing force provided by the tension spring has pivoted the closure element 3 against the through-opening 2. The closure element 3 is dimensioned such that, in the direction of flow, an outer contour of the closure element 3 encloses an inner contour of the through-opening 2, and thus the closure element 3 completely covers the through-opening 2 and thus closes the through-opening 2.

[0021] Fig. 2d shows a sectional view of the fire damper 1 according to Fig. 1 with the closure element 3 in the closed position. Due to the pendulum mounting of the closure element 3 in the guide system, a cross-sectional plane 17 of the disc-shaped closure element 3 can be inclined relative to a cross-sectional plane of the through-opening 2 before assuming the closed position, ensuring that the closure element 3, in its closed position, rests flush against the first wall element 7 accommodating the through-opening 2. When the closure element 3 is in its closed position, the tension spring is not completely relaxed but continues to exert a tensile force.The tensile force of the tension spring 5 transmitted to the closure element 3 via the guide system 1 then causes a force component of the closure force to press a surface 3a of the closure element 3 facing the first wall element 7 against a surface 7a of the first wall element 7 facing the closure element 3 in the closed position of the closure element 3 completely along the through opening 2.

[0022] For better sealing, seals can be provided on the side 7a of the first wall element 7 facing the closure element 3 or on the side 3a of the disc-shaped closure element 3 facing the first wall element 7. These seals can also be installed in grooves in the first wall element 7 or in the disc-shaped closure element 3. No seals are shown in the illustrations.

[0023] In an alternative embodiment, the disc-shaped closure element 3 dips at least partially into the through-opening 2 to assume its closed position. Seals can also be provided in the cylindrical surface of the through-opening 2 or the cylindrical outer surface of the disc-shaped closure element 3.

[0024] To protect against heat and / or contamination, the drive elements 5 can be separated from the air-conducting space by heat- and / or dirt-impermeable separating elements. Heat-impermeable separating elements ensure that the drive elements 5 remain cooler than the air-conducting space in the event of a fire. For example, in the case of drive elements 5 designed as springs, the tension of these springs is maintained. The dirt-impermeable separating elements protect the drive elements 5 from dirt particles carried by the air flow, preventing the drive elements from becoming contaminated and thus impairing their functionality.

[0025] In further embodiments (not shown), elastically or plastically deformable and / or melting air guide elements are integrated into the air-conducting space. When the closure element 3 is open (closure element in the open position), these serve to optimally guide the air between the through-opening 2 and the further through-opening 9, so that a flow channel that is largely free of steps and gaps is formed in the air-conducting space along the flow direction. The flow channel along the through-opening 2 thus has an advantageous design with regard to hygiene, cleaning options, prevention of particle accumulation, and minimization of pressure loss when flowing through the device as a single pressure loss point. These air guide elements can, for example, be fixed to the inside of the sleeve element 15 facing the air-conducting space or to the side of the closure element 3 facing the through-opening 2.Elastically deformable air guide elements yield elastically or retract when the closure element 3 is closed, so that the closing movement of the closure element 3 is not impeded. Plastically deformable air guide elements are deformed when the closure element 3 moves towards the guide system 4, whereby the air guide elements are designed in such a way that the force required for the deformation is so low that the closing movement of the closure element 3 is not impeded. In the event of a fire, melting or evaporating air guide elements are melted or evaporated by the associated temperature increase before the closure element 3 is moved towards the through opening 2 and then do not hinder the closing movement of the closure element 3.

[0026] Fig. 3a shows a spatial representation of a further embodiment of the fire damper 1 according to the invention. Here, too, a through opening 2 is provided in a first wall element 7. The fire damper 1 is arranged in the ventilation duct such that the flow guided in the ventilation duct is guided through the through opening 2. The closure element 3 is designed as a slide and has two shaped elements, which in the illustrated embodiment are designed as axially aligned bolts 19. These bolts 19 are guided in a guide system in a housing 20 of the fire damper 1. The drive element 5 of the fire damper 1 is formed by two tension springs, wherein each tension spring is fixedly connected to the housing 20 with a (force-transmitting) end 5a. One of the other ends 5b of each tension spring is fastened to one of the bolts 19. The closure element 3 designed as a slide element is in its open position.In this position of the closure element 3, the tension springs are tensioned, exerting a closing force on the closure element 3. The retaining element 6 fixes the closure element 3 in the open position. In the illustrated embodiment, the retaining element 6 is designed as a fusible link that connects the housing 20 of the fire damper to the closure element 3.

[0027] The guide system is formed by two parallel guide rails 22 embedded in the housing 20, wherein the bolts 19 attached to the closure element 3 are slidingly or ball-bearing mounted in these guide rails 22. However, only one of the guide rails 22 and only one of the bolts 19 is visible in the illustration. The closure element 3 is located in Fig. 4a in its open position, with the bolts 19 located at an end of the guide rails 22 facing away from the through-opening 22b. The (force-transmitting) ends 5a of the tension springs fixed to the housing 20 are thus arranged stationary relative to the guide rails 22. The holding element 6, designed as a fusible link, is located between an angle 23a attached to the closure element 3 and an angle 23b attached to the housing 20.

[0028] The closure element 3 is pivotally mounted relative to the guide rails 22 via the bolts 19 (analogous to the pivoting mounting of the closure element 3 relative to the legs 4a, 4b in the previous embodiment). For such pivoting mounting of the closure element 3, the bolts 19 can, for example, be firmly connected to the closure element 3 and have a round outer contour in the guide rails 22, so that the bolts 19 can rotate in the respective guide rail 22. Likewise, the bolts 19 can also be designed such that they can only be moved in the respective guide rail 22 along this guide rail 22. The bolts 19 are then embedded in the closure element 3 in such a way that they can be rotated about their longitudinal axis on the closure element 3.

[0029] The guide rails 22 each have a section at their ends 22b facing the passage opening 2 which is inclined in the direction of the passage opening 2. The rest of the guide rails 22 runs essentially parallel to the first wall element 7. This leads to the fact that (based on the illustration in Fig. 4a ) the closure element 3, when transitioning from the open position to the closed position, executes not only a horizontal movement (= movement perpendicular to the flow direction) towards the closed position but also a vertical movement in the direction of the through-opening 2 shortly before reaching the closed position. The vertical movement (= movement parallel to the flow direction) ensures that the closure element 3, in its closed position, lies flush with the first wall element 7 at the through-opening 2.Before assuming the closed position, the closure element 3 is slightly spaced from the side 7a of the first wall element 7 facing the closure element 3, so that during the horizontal movement of the closure element 3, at most minimal friction losses occur between the side 3a of the closure element 3 facing the first wall element 7 and the side 7a of the first wall element 7 facing the closure element 3, and thus the horizontal movement of the closure element 3 is smooth and only slightly prone to errors. The pressing of the closure element 3 against the first wall element 7 with the drive element 5 is force-controlled and not path-controlled, with the end position of the closure element 3 being reached when the drive element 5 exerts its full force on the closure element 3.

[0030] Fig. 3b shows the fire damper 1 from Fig. 3a ,However, here the closure element 3 is in its closed position. In this position of the closure element 3, the bolts 19 are located in the sections of the guide rails 22 that are inclined towards the through-opening 2. Since the tension springs 5 ​​are not completely relaxed when the closure element 3 is in the closed position, a force component of the closure force still acts on the closure element 3. As a result, here too, the surface 3a of the closure element 3 facing the first wall element 7 is pressed all the way along the through-opening 2 against the surface 7a of the first wall element 7 facing the closure element 3 by the force component of the closure force.

[0031] In Fig. 3c A spatial representation of another embodiment of the fire damper 1 is shown. Except for the design of the guide rails 22, the fire damper 1 is in Fig. 3c identical to the fire damper 1 according to Fig. 3a or Fig. 3b . The guide rails 22 of the fire damper 1 according to Fig. 3c are inclined towards the passage opening 2, so that (starting from Fig. 3c ) During the entire horizontal movement of the closure element 3 from the open position to the closed position, the closure element 3 is also guided vertically downwards (in the direction of the side 7a of the first wall element 7 facing the closure element 3). In the closed position, the side 3a of the closure element 3 facing the first wall element 7 is then pressed against the side 7a of the first wall element 7 facing the closure element 3 by the closure force acting on the closure element 3.

[0032] Fig. 4a shows a top view of the fire damper 1 according to Fig. 3a . In addition to the already existing Fig. 3a In accordance with known components, a flow channel-forming insert 21 is further provided in the through-opening 2. This flow channel-forming insert 21 forms, on the side 7a of the first wall element 7 facing the closure element 3, a flow channel extending from the through-opening below the open side of the closure element 3. Since the flow channel-forming insert 21 continues the flow channel on the side 7a of the first wall element 7 facing the closure element 3, the flow is guided along the through-opening 2 past the lower edge of the closure element 3, so that the edges and gaps formed by the closure element 3 are bypassed, thus forming a flow channel that is largely free of steps and gaps (as with the air guide elements mentioned above).Thus, the flow channel along the through-opening 2 has an advantageous design with regard to hygiene, ease of cleaning, prevention of particle accumulation, and minimization of pressure loss during flow through the device as a single pressure loss point. The flow channel-forming insert 21 is made of a thin, deformable material in the illustrated embodiment.

[0033] In Fig. 4b the fire damper 1 is off Fig. 4a can be seen, with the closure element 3 in its closed position. The temperatures occurring in the event of a fire release the fusible link, so that the connection between the housing 20 and the closure element 3 is severed. To assume the closed position, the closure element 3, designed as a slide element, moves downwards, driven by the closure force, thereby crushing the flow channel-forming insert 21. When the flow channel-forming insert is crushed (deformed), it is pushed away from the through-opening. Fig. 4b shows the flow channel-forming insert 21 in its crushed final position. In the closed position, the tension springs are less tensioned than in the open position, but not completely relaxed, so that a force component of the closure force continues to act on the closure element 3 even in the closed position.

[0034] Alternatively, the flow channel-forming insert 21 can also be made of material that melts, burns, or evaporates at temperatures occurring in the event of a fire before the closure element 3 transitions from its open position to its closed position. Likewise, the flow channel-forming insert 21 can also be designed such that it is pushed away from the through-opening 2 when the closure element 3 closes, without deformation of the flow channel-forming insert 21 occurring. For this purpose, the flow channel-forming insert 21 can, for example, be mounted in a further guide system in the housing 20. However, the flow channel-forming insert 21 of the fire damper 1 is not mandatory.

[0035] The design of the fire damper 1 according to the invention according to Fig. 3a bis Fig. 4b However, it is not limited to shaped elements configured as bolts 19. The shaped elements can also be, for example, sliding blocks or pins, or other shaped elements that are each mounted and guided in the guide rails 22 in a corresponding manner.

[0036] In alternative embodiments of the exemplary embodiments listed, the drive element 5 is a motor with a rack and pinion drive, wherein the motor can be, for example, a spring return motor or an electric motor.

[0037] In further refinements of the exemplary embodiments listed, the sleeve element 15 and / or the closure element 3 and / or the first wall element 7 are constructed from sheet metal elements with an insulating insert. In another embodiment, the sleeve element 15 and / or the closure element 3 and / or the first wall element 7 are formed from a sandwich construction made of sheet metal and insulating material or from insulating material. The drive element 5 is optionally thermally insulated from its surroundings, although no thermal insulation is shown in the illustrations.

[0038] In all illustrated embodiments, the through-openings 2 in the first wall element 7 are round. However, the fire damper 1 according to the invention is not limited to round through-openings 2. In principle, the through-opening 2 can have any cross-section, for example, a rectangular cross-section.

[0039] In all of the aforementioned embodiments, to further improve the seal, at least one sealing element is optionally arranged between the side 3a of the closure element 3 facing the first wall element 7 and the side 7a of the first wall element 7 facing the closure element 3. This sealing element can also be partially embedded in grooves in the closure element 3 or the first wall element 7. However, such seals are not shown in the illustrations.

[0040] Fig. 5 shows the fire damper according to Fig. 3a , but with flow channel-forming insert 21. Bezugszeichenliste

[0041] 1 Fire damper 2 Passage opening 3 Closure element 3a Side of closure element 3 facing the first wall element 7 4 Guide system 4a Leg 4b Leg 5 Drive element 6 Holding element 7 First wall element 7a Side of first wall element 7 facing the closure element 8 Second wall element 9 Further passage opening 10a Angle 10b Angle 11 Joint 12 Pendulum bearing 13 Intersection point 14 Angle 15 Sleeve element 16a Fastening element 16b Fastening element 17 Cross-sectional plane 18 Cross-sectional plane 19 Bolt 20 Housing 21 Flow channel-forming insert 22 Guide rail 22a End of guide rail 22 facing the passage opening 2 23a Angle 23bAngle

Claims

1. Fire damper (1) for an air duct through which air flows, comprising a duct opening (2), a first wall element (7) accommodating this duct opening (2), a closure element (3), a guide system (4), a drive element (5) and a retaining element (6), wherein the closure element (3) can be brought into an open position and a closed position, and wherein, when the closure element (3) is in the closed position, an outer contour of the closure element (3) encloses an inner contour of the duct opening (2), and thus the closure element (3) covers the duct opening (2), and wherein, when the closure element (3) is in its open position, it opens up the duct opening (2) and the retaining element (6) fixes the closure element (3) in the open position, and wherein the retaining element (6) is designed to release the closure element (3) in the event of a fire, and wherein the guide system (4) is designed to guide the closure element (3), driven by a closing force provided by the drive element (5), in the direction of the duct opening (2), characterised in that the closure element (3) is pivotably mounted in the guide system (4) via a pendulum bearing, such that a cross-sectional plane (17) of the closure element (3) can be tilted relative to a cross-sectional plane (18) of the duct opening (2) before the closed position is reached, and in that the guide system (4) is designed in such a way that, when the closure element (3) is in the closed position, a force component of the closing force acting across the entire circumference of the duct opening (2) presses a surface (3a) of the closure element (3) facing the first wall element (7) against a surface (7a) of the first wall element (7) facing the closure element (3), and that the guide system (4) comprises at least one joint (11), at least one pendulum bearing (12), and at least one support element with two legs (4a, 4b) arranged at an angle to one another, and that the support element is rotatably fixed to the first wall element (2) at the intersection point of the leg axes via the joint (11), and that the closure element (3) is fixed to one of the legs (4a, 4b) via the pendulum bearing (12), and the drive element (5) is connected to the end of the other leg (4a, 4b).

2. Fire damper (1) according to claim 1, characterised in that the fire damper (1) comprises a second wall element (8) with a further duct opening (9), and that this second wall element (8) is arranged at a distance on a side of the first wall element (7) facing the closure element (3), and that the drive element (5) is fixed with one force-transmitting end to the support element, and with the other force-transmitting end to the second wall element (8).

3. Fire damper (1) according to claim 2, characterised in that, when the closure element (3) is in the open position, the retaining element (6) connected to the closure element (3) is fixed to the second wall element (8).

4. Fire damper (1) according to claim 2 or 3, characterised in that a space spanned between the first wall element (7) and the second wall element (8) is surrounded by a sleeve element (15) of the fire damper (1).

5. Fire damper (1) according to claim 4, characterised in that the sleeve element (15) comprises at least one fastening element (16a, 16b) for anchoring the sleeve element (15) in or on a building wall, or in, on or under a building ceiling.

6. Fire damper (1) for an air duct through which air flows, comprising a duct opening (2), a first wall element (7) accommodating this duct opening (2), a closure element (3), a guide system (4), a drive element (5) and a retaining element (6), wherein the closure element (3) can be brought into an open position and a closed position, and wherein, when the closure element (3) is in the closed position, an outer contour of the closure element (3) encloses an inner contour of the duct opening (2), and thus the closure element (3) covers the duct opening (2), and wherein, when the closure element (3) is in its open position, it opens up the duct opening (2) and the retaining element (6) fixes the closure element (3) in the open position, and wherein the retaining element (6) is designed to release the closure element (3) in the event of a fire, and wherein the guide system (4) is designed to guide the closure element (3), driven by a closing force provided by the drive element (5), in the direction of the duct opening (2), characterised in that the closure element (3) is pivotably mounted in the guide system (4) via a pendulum bearing, such that a cross-sectional plane (17) of the closure element (3) can be tilted relative to a cross-sectional plane (18) of the duct opening (2) before the closure position is reached, and in that the guide system (4) is designed in such a way that, when the closure element (3) is in the closed position, a force component of the closing force acting across the entire circumference of the duct opening (2) presses a surface (3a) of the closure element (3) facing the first wall element (7) against a surface (7a) of the first wall element (7) facing the closure element (3), and that the guide system (4) comprises two parallel guide rails (22), and that the closure element (3) comprises shaped elements in the cross-sectional plane (17) of the closure element (3), and that each of these shaped elements is mounted in a respective guide rail (22), and that the shaped elements mounted in the guide rails (22) form the pendulum bearing of the closure element (3), and that the guide rails (22) are inclined, at least in sections, in the direction of the duct opening (2), and that one force-transmitting end of the drive element (5) is arranged in a stationary manner with respect to the guide rails (22), and that the other force-transmitting end of the drive element (5) is connected in each case to one of the shaped elements.

7. Fire damper (1) according to claim 6, characterised in that the guide rails (22) are embedded in a housing (20) of the fire damper (1).

8. Fire damper (1) according to claim 6 or 7, characterised in that the shaped elements are bolts (19), sliding blocks or pins.

9. Fire damper (1) according to claim 7 or 8, characterised in that the housing (20) comprises at least one fastening element (16a, 16b) for anchoring the housing in or on a building wall, or in, on or under a building ceiling.

10. Fire damper (1) according to one of the preceding claims, characterised in that the housing (20) and / or the sleeve element (15) and / or the closure element (3) and / or the wall element (7) are designed as a sheet metal housing with an insulating insert, or as a sandwich construction made of sheet metal and insulating material, or as insulating material.

11. Fire damper (1) according to one of the preceding claims, characterised in that the drive element (5) is thermally insulated from its surroundings.

12. Fire damper (1) according to one of the preceding claims, characterised in that the drive element (5) is a spring element, a spring-return motor with rack-and-pinion drive or an electric motor with rack-and-pinion drive.

13. Fire damper (1) according to one of the preceding claims, characterised in that at least one sealing element is arranged between a side (3a) of the closure element (3) facing the first wall element (7) and a side (7a) of the first wall element (7) facing the closure element (3).

14. Fire damper (1) according to one of the preceding claims, characterised in that the retaining element (6) is designed as a fusible link.

15. Fire damper (1) according to one of the claims 6 to 14, characterised in that the duct opening (2) comprises a flow-channel-forming insert (21) and this flow-channel-forming insert (21) forms a flow channel extending from the duct opening (2) along the open closure element (3) on the side (7a) of the first wall element (7) facing the closure element (3), and in that the flow-channel-forming insert (21) is designed to melt, burn or evaporate at temperatures that occur in the event of fire before the closure element (3) transitions from its open position to its closed position, or in that the flow-channel-forming insert (21) is designed to be deformed and / or pushed away from the duct opening (2) by the closure element (3) during its transition from the open position to the closed position.