A smoke exhaust damper

Abstract

A smoke exhaust damper comprising: • An outer frame defining a first channel; and • An inner frame defining a second channel; and • a door element configured to close off the second channel; wherein the inner frame is at least partially inserted in the outer frame, thereby defining a gap between the inner frame and the outer frame with the inner frame and outer frame being aligned in a same direction X and with said gap circumscribing the inner frame; characterized in that an insert is present in said gap, said insert being made from a material having a thermal conductivity of equal to or less than 0,25 Wm-1K-1 and said insert circumscribing the inner frame.

Description

Field of the Invention

[0001] The present invention concerns a smoke evacuation shutter, in particular a smoke evacuation shutter to be installed in a wall section between a room and a smoke evacuation shaft.Background to the Invention

[0002] Buildings and especially multistore buildings become more and more complex. Increasing insulation and ventilation standards require an improved and flexible fire protection.

[0003] Fire protection includes, amongst others, fire shutters and smoke exhaust dampers. Fire shutters have a primary function of preventing a fire to spread through a building and are designed to close openings between building compartments in case of a fire and to withstand the heat generated by the fired during a predetermined period of time. Smoke exhaust dampers have a primary function of allowing the extraction of smoke from a fire from a building. Smoke exhaust dampers are typically installed in relation to a smoke exhaust shaft or duct. This shaft or duct is operated at an under pressure in view of the building and links several compartments of a building to the atmosphere.

[0004] In order to allow an effective exhaust smoke from a building, smoke exhaust dampers must be driven to or maintained in an open position when located in a compartment where smoke is generated by a fire, thereby allowing smoke from the compartment to be evacuated through the exhaust shaft or duct and driven to or maintained in a closed position when located in a compartment where no fire is raging, this to prevent that heat and smoke travelling through the exhaust shaft or duct enters that compartment and to maximally maintain the under pressure in the exhaust shaft or duct such as to extract smoke in a most efficient manner possible.

[0005] To guarantee a smoke exhaust damper's functionality, it has to meet two basic requirements, namely the so-called maintenance of opening and the so-called maintenance of closing.

[0006] This means that a smoke exhaust damper shall be capable to maintain it's open position in case of a fire for a predetermined period, this without the opening being obstructed in any way and that the smoke exhaust damper shall also be capable to maintain it's closed position and prevent a fire or smoke to travel through the smoke exhaust damper in case of exposure to heat for a predetermined amount of time.

[0007] Smoke exhaust dampers having an aluminum frame exist, which frame melts away during an prolonged exposure to fire. In such case, the door element of the smoke exhaust damper is no longer supported by the frame and may fall. When this happens, the "maintenance of opening" is not assured in for the smoke exhaust damper in open position, and the "maintenance of closing" is not assured for the smoke exhaust damper in closed position.

[0008] The present invention aims at limiting the risk of a door element of a smoke exhaust damper to become unsupported by the frame of that damper in case of a fire.Summary of the Invention

[0009] The present invention meets the above mentioned market demand and provides for a smoke exhaust damper 1 comprising: An outer frame 5 defining a first channel 6; and An inner frame 7 defining a second channel 8; and a door element 3 configured to close off the second channel; wherein the inner frame 7 is at least partially inserted in the outer frame 5, thereby defining a gap between the inner frame and the outer frame with the inner frame and outer frame being aligned in a same direction X and with said gap circumscribing the inner frame; wherein an insert 11 is present in said gap, said insert being made from a material having a thermal conductivity of less than 0,25 Wm-1K-1 and said insert circumscribing the inner frame 7.

[0010] The presence of both an outer frame and an inner frame allows for a smoke evacuation shutter that remains its integrity and air tightness versus a surrounding wall or duct sidewall in case of facing high heat conditions from either side of the smoke exhaust damper.

[0011] The insert preferably contacts both the inner frame and the outer frame over a section of both frames extending in the X-direction. The insert may be made of a material of the group comprising: gypsum, calcium silicate, glass reinforced gypsum, magnesium-based materials, perlite or vermiculite and admixtures thereof.

[0012] The inner frame is preferably made of a material withstanding temperatures of above 700°C, such as for example steel.

[0013] The outer frame is preferably made of aluminum.

[0014] The smoke exhaust damper of the invention preferably has an installation orientation, with a proximal side and distal side, said insert comprising a distal part protruding from the inner frame towards the distal side of the smoke exhaust damper.

[0015] The smoke exhaust damper of the invention preferably has an installation orientation, with a proximal side and distal side, said insert comprising a proximal part protruding from the inner frame towards the proximal side of the smoke exhaust damper.

[0016] The door element preferably comprises at least one distal panel and / or at least one proximal panel, whereby the at least one distal panel comprises a first circumferential edge of the door element that, in a closed position of the door element, faces the distal part of the insert and whereby the at least one proximal panel comprises a second circumferential edge of the door element that, in a closed position of the door element, faces the proximal part of the insert, whereby a strip of intumescent material is provided between the first circumferential edge of the door element and the distal part of the insert and / or between the second circumferential edge of the door element and the proximal part of the insert.

[0017] Brief Description of the Appended Figures Fig. 1 shows a cross section of a smoke exhaust damper according to the present invention installed in a wall section; Fig. 2 shows a perspective view of the smoke exhaust damper according to the present invention Fig. 3 shows in more detail the part indicated with the reference II of the smoke exhaust damper of Fig. 1. Detailed Description of the invention

[0018] Fig. 2 shows a smoke exhaust damper 1 according to the present invention comprising a frame 2 and a door element 3 mounted thereto, whereby the door can move between an open position and a closed position, the closed position being showed in Fig. 2.

[0019] Fig. 1 shows a cross section of the same smoke exhaust damper as shown in Fig. 2, whereby this smoke exhaust damper is installed in a wall section 4.

[0020] Fig. 3 shows in more detail the part of the smoke exhaust damper indicated in Fig. 1 by III. This detailed section illustrates a cross section of the frame 2 and its interaction with the door element 3 of the smoke exhaust damper when in a closed position. In accordance with the present invention, the frame comprises an outer frame 5 defining a first channel 6 and an inner frame 7 defining a second channel 8 that in this case corresponds to the actual through channel of the smoke exhaust damper and that is in this case closed off by the door element 3. Both the first and second channel extend in a same X-direction, whereby the second channel 8 has a smaller cross section than the first channel 6, especially as the outer frame 5 and inner frame 7 are spaced apart from one another in a direction perpendicular to the X-direction, leaving a gap between both frames 5 and 7, said gap circumscribing the inner frame 7 such that the inner frame 7 does not comprise a point where it directly contacts the outer frame 5. It is understood that said gap between both frames 5 and 7 surrounds the inner frame 7 while at the same time said gap is surrounded by the outer frame 5.

[0021] The smoke exhaust damper illustrated in Fig. 1, 2 & 3 has an installation orientation, meaning that it is intended for being installed in a particular orientation between a room and a smoke exhaust shaft or smoke exhaust duct, whereby in case of smoke evacuation, the smoke travels from the room side through the smoke exhaust damper, in particular the second channel 8 thereof into or towards the smoke exhaust shaft of smoke exhaust duct. The side of the smoke exhaust damper facing the room is further referred to as the air inlet or proximal side P, whereas the side of the smoke exhaust damper facing the smoke exhaust shaft of smoke exhaust duct is further referred to as the air outlet or distal side D.

[0022] In the embodiment of the smoke exhaust damper illustrated in the Figs. 1 to 3, the outer frame 5 defines a casing 9 at the proximal side of the smoke exhaust damper, which casing 9 is configured to abut a portion of a building wall or duct wall surrounding the opening wherein the smoke exhaust damper is installed. This casing extends in a predominant direction Y, perpendicular to the X-direction. From the casing 9 extends a leg 10 of the outer frame towards the distal side of the smoke exhaust damper, which leg defines the actual first channel. In this case the leg 10 of the outer frame partially protrudes from the second channel 8 in the X direction towards the proximal side P of the smoke exhaust damper.

[0023] The outer frame 5 is preferably made from a metal material, in particular aluminum.

[0024] The inner frame 7 in this case comprises a single wall, but may as well comprise a multilayered wall or a wall composed of comparted hollow profiles. The inner frame 7 is partially inserted in the first channel and partially protrudes therefrom towards the distal side D of the smoke exhaust damper. The inner wall is preferably made from a material having a melting point of above 700°C, more preferably it is made from a material that is resistant to a temperature of at least 7000C whereby with resistant is meant that the inner frame maintains its integrity up to that temperature of 700°C. The inner frame is preferably manufactured in steel.

[0025] In accordance with the present invention an insert 1 1 is present in the above-mentioned gap defined between the outer frame 5 and the inner frame 7. The insert 11 provides a thermal insulation between the outer frame 5 and the inner frame 7 and circumscribes the inner frame, preferably in its entirety over at least a section of the length of the inner frame 7 measured in the X-direction. In other words, insert 1 1 surrounds (i.e. encloses) at least partially the inner frame 7 while at the same time the insert 1 1 is surrounded (i.e. enclosed) by the outer frame 5.

[0026] The insert may hereby comprise a single element or may comprises a plurality of elements positioned one next to another to define a continuous insulation between the inner frame and the outer frame.

[0027] As shown in Fig. 3, the insert 11 comprises a main part 11a situated between the inner and outer frames and extending along the inner frame 7, a proximal part 11p, protruding from the inner frame in the X-direction towards the proximal end of the smoke exhaust damper; and a distal part 11d, protruding from the inner frame in the X-direction towards the distal end of the smoke exhaust damper.

[0028] The main part 11a preferably has a width that is equal to or substantially equal to the width of the gap between the inner and outer frames, such that the insert 1 1 at least locally contacts both the inner frame 7 and the outer frame 5.

[0029] The proximal part 11p preferably has a width larger than the width of the main part 11a such that this proximal part 11p protrudes from the main part in the Y-direction towards the center of the second channel, whereby at a free end 12 of that proximal part 11p a strip of intumescent material is provided 13. This proximal part 11p is covered by the casing 9 defined by the outer frame at the proximal end of the smoke exhaust damper.

[0030] The distal part 11d of the insert 1 1 defines a wall surface 14 oriented perpendicular to the U-direction and facing the centerline X-X second channel 8. On this wall surface 14 a second strip 15 of intumescent material is provided.

[0031] Further strips 16 of intumescent material are provided on a surface 17 of the insert facing away the centerline X-X of the second channel, which strips of intumescent material, in case of heat activation thereof are intended to fill a potential space between the insert and edges 18 of the wall or duct defining the opening therein wherein the smoke exhaust damper is installed or to be installed.

[0032] On the above mentioned wall surface 14 of the distal part 11d of the insert, facing the centerline X-X of the second channel, a sealing strip 19 may be provided that extends towards the centerline X-X of the second channel. Alternatively, this sealing strip is provided on the inner frame.

[0033] The insert 11 is preferably made of a material selected from the group comprising gypsum, CaSi, glass reinforced gypsum, magnesium based materials, perlite or vermiculite and admixtures thereof, whereby calcium silicate is preferred. The thermal conductivity of the insert if of a value equal to or less than 0,25 Wm -1< K -1< .

[0034] The door element 3 of the smoke exhaust damper in this case comprises two main panels 20 & 21 extending a plane perpendicular to the X-direction in a closed position of the door. A first of these panels, further referred to as the proximal panel 20, faces the proximal end P of the smoke exhaust damper when in a closed position, whereas the other panel, further referred to as the distal panel 21, faces the distal end D of the smoke exhaust damper when in a closed position.

[0035] As illustrated in Fig. 3, in a closed position of the door element 3, the proximal panel 20 comprising a circumscribing edge 20a facing the proximal part 11p of the insert and the strip of intumescent material 13 provided thereon. In the same closed position, the distal panel 21 comprising a circumscribing edge 21a facing the distal part 11d of the insert and the second strip 15 of intumescent material provided thereon, whilst it also contacts the sealing strip 19.

[0036] The functioning of the smoke exhaust damper according to the present invention is as follows.

[0037] Upon detection of a fire, a smoke exhaust damper in proximity of that fire, is placed in an open position, wherein the door element 3 does not block the second channel of the smoke exhaust damper. This allows smoke to be evacuated from a room to a smoke exhaust shaft or smoke exhaust duct. In this case the smoke exhaust damper can be exposed to very high temperatures and yet needs to maintain the second channel open for a predetermined period of time to allow efficient and effective exhaust of smoke. While the outer frame may not be resistant to such high temperatures for an extended period of time, the inner frame is as well as the insert.

[0038] Due to the heat generated by the fire, the strips of intumescent material 13, 15 and 16 will expand (at a temperature well below the temperature at which the outer frame may lose its structural integrity), whereby in particular the strips 16 will effectively anker the smoke exhaust damper in place, whereby the second channel will remain open due to the presence of the inner frame.

[0039] Fire exhaust dampers not situated proximate to the fire, but associated with a smoke exhaust shaft or smoke exhaust duct of another smoke exhaust damper that is situated in proximity of the fire (and thus maintained in an open position), will be placed in a closed position to prevent smoke present in the smoke exhaust shaft or smoke exhaust duct from spreading in the building and to allow to efficiently maintain an under pressure in that smoke exhaust shaft or smoke exhaust duct. Due to the heat of the smoke evacuated through the smoke exhaust shaft or smoke exhaust duct, one or more, if not all of the strips 13, 15, 16 of intumescent material of the concerned smoke exhaust dampers will expand. The strips 13 and 15, facing the centerline X-X of the second channel of these smoke exhaust dampers, will thereby seal of the potential air gap between the door element and the frame of the smoke exhaust dampers, whereas the strips 16 facing away the centerline X-X of the second channel, will close-off a potential gap between the frame and the wall wherein the smoke exhaust damper is installed.

[0040] Due to the insert protruding from the inner frame both towards the proximal side P and the distal side D of the smoke exhaust damper, a heat transfer through the frame from the distal side (hot due to evacuated smoke) to the proximal side P of that smoke exhaust damper is limited.

Claims

1. A smoke exhaust damper 1 comprising: • An outer frame 5 defining a first channel 6; and • An inner frame 7 defining a second channel 8; and • a door element 3 configured to close off the second channel; wherein the inner frame 7 is at least partially inserted in the outer frame 5, thereby defining a gap between the inner frame and the outer frame with the inner frame and outer frame being aligned in a same direction X and with said gap circumscribing the inner frame; characterized in that an insert 11 is present in said gap, said insert being made from a material having a thermal conductivity of equal to or less than 0,25 Wm-1K-1 and said insert circumscribing the inner frame 7.

2. The smoke exhaust damper according to claim 1, said insert 1 1 contacting both the inner frame and the outer frame over a section of both frames extending in the X-direction.

3. The smoke exhaust damper according to claim 3, the inner frame made of a material having a melting point above 700°C.

4. The smoke exhaust damper according to any of the preceding claims, the inner frame made of a material resistant to temperatures of at least 700°C, preferably steel.

5. The smoke exhaust damper according to any of the preceding claims, the inner frame being made of a different material than the outer frame.

6. The smoke exhaust damper according to any of the preceding claims, the inner frame being made from a material having a higher heat resistance than the material of the outer frame.

7. The smoke exhaust damper according to any of the preceding claims, the outer frame being at least partially made of aluminium.

8. The smoke exhaust damper, the insert is made of a material of the group comprising: gypsum, CaSi, glass reinforced gypsum, magnesium based materials, perlite or vermiculite and admixtures thereof.

9. The smoke exhaust damper according to any of the preceding claims, having an installation orientation, with a proximal side and distal side, said insert comprising a distal part 11d protruding from the inner frame towards the distal side of the smoke exhaust damper.

10. The smoke exhaust damper according to any of the preceding claims, having an installation orientation, with a proximal side and distal side, said insert comprising a proximal part 11p protruding towards the proximal side of the smoke exhaust damper.

11. The smoke exhaust damper according to claim 9, said door element comprising at least one distal panel that, in a closed position of the door, is positioned distal from the second channel with a first circumferential edge facing the distal part of the insert and in that a strip of intumescent material is provided between said first circumferential edge of said door element and said distal part of the insert.

12. The smoke exhaust damper according to claim 10, said door element comprising at least one proximal panel that, in a closed position of the door, is positioned proximal from the second channel with a second circumferential edge facing the proximal part of the insert and in that a strip of intumescent material is provided between said second circumferential edge of said door element and said proximal part of the insert.

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