WO2022131989A1

WO2022131989A1 - Sealing device

Info

Publication number: WO2022131989A1
Application number: PCT/SE2021/051134
Authority: WO
Inventors: Erik Lans
Original assignee: Camfil Ab
Priority date: 2020-12-16
Filing date: 2021-11-12
Publication date: 2022-06-23
Also published as: SE2051471A1; SE544656C2

Abstract

A sealing device (1) comprising a gasket (5) configured to seal a gap (2) between a first element (3) and a second element (4), wherein the gasket is arranged to be located in the gap (2) and to be in contact with the first and the second elements (3,4) during use, the sealing device comprising: a gasket (5) comprising two elongated gasket members (5a, 5b), where an inner 5 elongated gasket member (5a) is configured to surround an area (A), and an outer elongated gasket member (5b) is configured to surround the inner gasket (5a) and said area (A); and a carrier member (6), extending along the length of the elongated gasket members (5a,5b), and said elongated gasket members (5a,5b) being attached to the carrier member so that they are held in position on a distance from each other so as to form an intermediate gasket space (8) 10 between the gasket members (5a,5b); and a channel (7) connecting the intermediate gasket space (8) with the surroundings and being configured to be connected to a pressure source, to allow application of pressure on the intermediate gasket space (8) during use.

Description

SEALING DEVICE

TECHNICAL FIELD

The present disclosure relates to sealing device configured to seal a gap between a first and a second element, one of said elements preferably being a filter frame.

BACKGROUND ART

In situations where it is necessary to seal off an interior space from the outside, gaskets are commonly used to seal off gaps between structures that enclose such an interior space to prevent passage of unwanted substances such as particles, fluids, gas or other contaminants through the gap. The gasket can thereby serve to keep the interior space clean, or to prevent unwanted substances from escaping from the interior space. In cases where the sealed off interior space contains equipment and/or substances which are particularly sensitive to contaminants, or contains substances which are hazardous and cannot be allowed to escape into the surrounding environment, it is especially important to ensure that the sealing is sufficiently leak tight. It is also important to ensure that the sealing does not become compromised, and thus it necessary to regularly check the sealing tightness of the gasket, to be able to detect any leakage. Standard methods for leakage detection are available, for example as described in e.g. ISO 10648-2, EN12237 or EN1886. In order to properly monitor leak tightness, it is important to provide the equipment with a sealing device allowing this. There is also a need of a sealing device that can be applied to equipment not originally designed for leak tightness monitoring.

SUMMARY

The present disclosure thus relates to sealing a gap between structural elements, and to provide a sealing device, which can provide improved leak tightness and allow monitoring of leak tightness to ensure that the sealing is always under control, in particular within air filtration. The present disclosure further aims at providing a sealing device by means of which existing equipment can be upgraded.

Accordingly, the present disclosure relates to a sealing device comprising a gasket configured to seal a gap between a first element and a second element, wherein the gasket is arranged to be located in the gap and to be in contact with the first and the second elements during use. The sealing device comprises a gasket comprising two elongated gasket members, where an inner elongated gasket member is configured to surround an area, and an outer elongated gasket member is configured to surround the inner gasket and the area ; and a carrier member, extending along the length of the elongated gasket members, and the elongated gasket members being attached to the carrier member so that they are held in position on a distance from each other so as to form an intermediate gasket space between the gasket members, and a channel connecting the intermediate gasket space with the surroundings and being configured to be connected to a pressure source, to allow application of pressure on the intermediate gasket space during use, and enabling connection of the sealing device to a of leak tightness monitoring system if desired. The first element is preferably a filter frame of an air filter and the second element is preferably a filter housing.

The carrier member may be a frame having a first surface and a second surface, said second surface being opposite to said first surface, and said first and second surfaces extending between the two elongated gasket members, whereby a first intermediate gasket space is partially confined by said first surface, and a second intermediate gasket space is partially confined by said second surface. At least one of the two elongated gasket members may be divided along its length, into an first gasket member portion and a second gasket member portion, wherein the first gasket member portion is/are attached to the first surface of the frame, and the second gasket member portion is/are attached to the second surface of the frame, and wherein the frame extends beyond at least one pair of said first and second gasket member portions in a direction transverse to the length of the elongated gasket members.

Alternatively, the carrier member may be an open framework extending between the elongated gasket members, and the two elongated gasket members may then be attached to the carrier member so that portions of the open framework are partially enclosed by the material of the two elongated gasket members.

The channel connecting the intermediate gasket space with the surroundings and being configured to be connected to a pressure source can be arranged through one of the two elongated gasket members.

If the carrier is a frame, the channel connecting the intermediate gasket space with the surroundings and being configured to be connected to a pressure source can be arranged through the frame. The frame can be a hollow structure having one or more inner openings arranged in said first and/or second surface and an outer opening arranged in a portion of the frame extending beyond the first and second gasket member portions, said outer opening being configured to be connected to a pressure source.

The present disclosure further relates to an air filtration apparatus comprising the above sealing device, a filter frame, and a filter housing, wherein the sealing device is located in a gap between the filter frame and the filter housing so that the gasket members of the sealing device are in contact with the filter frame and the housing; and to an air filtration system comprising an air filtration apparatus and a pressure source, which is connected to the intermediate space(s) of the sealing device, said pressure source preferably being configured to maintain a set pressure difference towards the surroundings. The air filtration system may suitably comprise a control sensor located between the pressure source and the surroundings, which control sensor may preferably being configured to communicate with an evaluation device.

The present disclosure also relates to a method of installing the above sealing device in the air filtration system, the method comprising the steps of: positioning the sealing device in the gap between the filter frame and the filter housing; mounting the filter frame to the housing so that the gasket members of the sealing device are in contact with the filter frame and the housing; and connecting the channel to the pressure source to allow a pressure to be applied on the intermediate gasket space(s) of the sealing device.

The present disclosure will become apparent from the detailed description given below. The detailed description and specific examples disclose preferred embodiments of the disclosure by way of illustration only. Those skilled in the art understand from guidance in the detailed description that changes and modifications may be made within the scope of the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The features and advantages of the present disclosure will be more fully appreciated by reference to the following illustrative and non-limiting detailed description of example embodiments of the present disclosure, when taken in conjunction with the accompanying drawings.

Figures la-b are a cross-sectional views schematically illustrating embodiments of a sealing device of the present disclosure;

Figure 2a-c are cross-sectional views schematically illustrating embodiments of a sealing device of the present disclosure wherein the carrier is in the form of a frame; Figure 3 is a cross-sectional view schematically illustrating another embodiment of a sealing device wherein the carrier is in the form of a frame;

Figure 4a shows a perspective view of a of a sealing device wherein the carrier is in the form of a frame;

Figure 4b shows a perspective view of a part of a sealing device wherein the carrier is in the form of a frame;

Figure 5a shows a perspective view of a of a sealing device wherein the carrier is in the form of an open framework;

Figure 5b shows a top view of a part of a sealing device wherein the carrier is in the form of an open framework;

Figure 6 is a cross-sectional view schematically illustrating a filter mounted in a filter housing and sealed by a sealing device of the present disclosure;

Figure 7 shows schematically a leak tightness monitoring system that can be connected to the sealing device of the present disclosure.

DETAILED DESCRIPTION

As mentioned above, the present disclosure relates to sealing of a gap between two structural elements in order to improve leak tightness and to allow monitoring thereof. In many situations, it may be necessary to seal off the interior volume of an enclosure or a room from the surrounding environment. This disclosure particularly relates to a device, which is configured to seal a gap between structural elements that enclose such an interior volume, to prevent passage of unwanted substances such as particles, fluids, gas or other contaminants through the gap, and to systems and methods related to that. The gasket serves to seal the gap to prevent any leakage through the gap. Thereby, the interior volume of the enclosure can be kept clean, which is important for example within the pharmaceutical industry or within manufacture of electrical components. Similarly, if the enclosure or room accommodates items or activities, which may release unwanted or hazardous substances, such as for example toxic or pathogenic substances, such substances can be prevented from escaping from the enclosure or room.

The sealing device of the present disclosure thus comprises a gasket configured to seal a gap between a first element and a second element, wherein the gasket is arranged to be located in the gap and to be in contact with the first and the second elements during use. The first element may typically be a movable or replaceable part, that is mounted to cover an access opening in an enclosure or room, such as for example a filter, or a hatch or door. The second element may typically be a structure against which the first element is held or mounted, such as for example a wall casing of the enclosure or room.

It may often be desired or necessary to provide fresh air to the sealed enclosure or room, or to vent out gases there from, also when the enclosure or room must be fully leak proof. In such cases a filter can be mounted in an opening between the interior of the sealed volume and the surrounding. Leakage between the filter and the adjacent structure, against which the filter is mounted, can of course not be accepted, and the gap between a filter frame holding the filter and the mounting structure or filter housing, is thus a position where the sealing device of the present disclosure may be of particular use. The filter may for example be of panel type, box type or V type and can have any of the filter classes E10, Ell, E12, H13, H14, U15, U16, U17 according to EN1822 or being classified according to ISO 16890.

The sealing device comprises a gasket comprising two elongated gasket members, where an inner elongated gasket member is configured to surround an area, and an outer elongated gasket member is configured to surround the inner gasket and the area. The area may typically be an opening between two spaces or compartments, such as an inlet or outlet opening in a room or enclosure. For example, if the first element which is to be sealed is a filter and the second element is a filter housing, the area surrounded by the elongated gasket members will be the surface of the filter. Accordingly, the gasket encircles the opening and seals the gap between the first and second elements, so that the encircled area is sealed off from the surrounding during use of the sealing device. By providing two elongated gasket members surrounding the opening to be sealed during use and being in contact with both the first and the second element, the leak tightness is improved since there is both an inward and an outward gasket member that contribute to the sealing, and since the surfaces of both the first and the second element are in contact with the gasket material of the elongated gaskets. The sealing device can thus be disposed between the first and second elements and seal the gap without any need of gluing a sealing element to the first or second element.

The gasket is held by a carrier member, which extends along the length of the elongated gasket members, thus also surrounding the area surrounded by the gaskets. The elongated gasket members are attached to the carrier member so that they are held in position on a distance from each other and so that an intermediate gasket space is formed between the gasket members. This facilitates handling of the gasket prior to mounting in the gap, and when the sealing device is mounted and positioned between the first and second elements the intermediate gasket space is confined partially also by the surfaces of the first and second elements. Further, the provision of the double gasket forming an intermediate gasket space there between allows for monitoring of leak tightness as will be described in more detail below.

The carrier member may be a frame onto which the gasket members are attached. The frame has opposing first and second surfaces, which extend between the two elongated gasket members. Thereby intermediate gasket spaces are formed between the gasket members on both sides of the frame, which are partially confined by the gasket members and frame surface between the gasket members, and which are separated from each other. Two separate intermediate gasket spaces allow separate leak tightness monitoring on each side of the frame. The frame is preferably made of a rigid or semi-rigid material, such as plastic material or metal, and can be a solid or hollow structure. The surface of the frame is suitably substantially flat and continuous between the elongated gasket members, so that the intermediate gasket spaces formed on each side of the frame are completely separated from each other. A carrier in the form of a frame provides a robust sealing device that is easy to handle.

The gasket members can be attached to the frame such that the sides of the frame extend partially into the gasket members, as shown schematically in Fig. 1. The frame might also be configured to have one or more portions protruding sideways so as to extend through the gasket member so as to be exposed on the outside of the gasket.

Alternatively, one or both of the two elongated gasket members may suitably be divided along its length, into a first gasket member portion and a second gasket member portion. The first portion is then attached to the first surface of the frame, and the second portion is attached to the second opposing surface of the frame. In this case, the frame extends beyond the pair of gasket member portions in a direction transverse to the length of the elongated gasket members, and is exposed outside the gasket members on one or both sides.

Alternatively, the carrier member can be an open framework extending between the elongated gasket members, and the two elongated gasket members may then be attached to the carrier member so that portions of the open framework are partially enclosed by the material of the two elongated gasket members. In this case, only one intermediate gasket space is formed between the gasket members, since the spaces on each side of the carrier are connected by the openings in the open framework. The open framework is suitably made of a rigid or semi-rigid material, such as plastic material or metal. The open framework can for example be in the form of a trellis or a latticework, or can be a flat undulating or zig zag shaped structure. As the carrier is an open framework, there is only one intermediate gasket formed between the elongated gasket members. A carrier in the form of a frame can be made very thin an flexible, and can be suitable for example in situations where the gap to be sealed is narrow.

The gasket can be any suitable gasket or seal that can be arranged as two elongated members, leaving a space between them. For example, the gasket may be made of e.g. foamed polyurethane, solid polyurethane potting, polyurethane gel, silicone gel, self-adhesive EPDM rubber (ethylene propylene diene monomer rubber), or self-adhesive neoprene. The gasket should be dimensioned to ensure a sufficient seal in the gap between the surfaces of the first and second elements where it is intended to be mounted, i.e. have a length corresponding to the length of the gap to completely encircle the area to be sealed off by the gasket, and a height exceeding the height of the gap to such an extent that a proper seal is obtained.

The two elongated gasket members may typically be connected to the carrier at a constant distance from each other, but alternatively the gasket members can be positioned at different distances from each other if desired, depending on the dimensions of the intended gap. The distance between the two elongated gasket members may preferably be 0.5 to 100 mm, more preferably 2-90 mm, most preferably 5-50 mm. The height of the sealing device, i.e. the distance between the surfaces of the gasket members that will be in contact with the first and the second elements during use may preferably be 0.5 to 50 mm, more preferably 1 to 40 mm. The cross-sectional area of the intermediate gasket space may preferably be 0.25 to 5000 mm², more preferably 2-2000 mm², when the sealing device is in use. The area to be sealed by the sealing device, i.e. the area A surrounded by the gasket, can typically be 250x250 mm to 1300x1900 mm.

A channel is provided in the sealing device to connect the intermediate gasket space with the surroundings. The channel is configured to be connected to a pressure source, to allow application of pressure on the intermediate gasket space during use, as will be explained in the following. The channel can be directed towards the area surrounded by the gasket, or toward the side of the gasket facing away from this area. A channel directed toward the surrounded area may be preferred since it may be easier to install, since the connection to a pressure source can be obtained also when the structure to be sealed was not initially adapted to connecting the gasket to pressure.

The channel can be arranged through one of the two elongated gasket members, toward the area surrounded by the gasket, or outward, away from the area surrounded by the gasket. It can be in the form of a tube extending through the gasket or a cylinder disposed in the gasket so as to connect the intermediate gasket space with the surroundings. In embodiments including intermediate gasket spaces on each side of the frame channels can be arranged through the gasket member portions separately connecting the two intermediate gasket spaces to a pressure source.

If the carrier is a frame as described above, the channel connecting the intermediate gasket space with the surroundings and being configured to be connected to a pressure source can be arranged through one of the two elongated gasket members or through the frame. If the frame is solid or substantially solid, the channel can be formed through the frame material, for example by drilling, so as to have an inner opening arranged in the first and/or second surface between the gasket members and an outer opening arranged in a portion of the frame extending beyond the first and second gasket member portions and being exposed on the outside of the sealing device. If the frame is a hollow structure, it can have one or more inner openings arranged in the first and/or second surface between the gasket members and an outer opening arranged in a portion of the frame extending beyond the first and second gasket member portions and being exposed on the outside of the sealing device. In this case, the frame in its entirety acts as a channel connecting the intermediate gasket spaces with the surrounding. Accordingly, the inner opening will be disposed within the intermediate gasket space and outer opening will be configured to be connected to a pressure source.

The channel connecting the intermediate gasket space with the surroundings may preferably be arranged toward the area (A) surrounded by the gasket. Alternatively, the channel may be arranged away from the area (A) surrounded by the gasket.

The first element is advantageously a filter frame of an air filter and the second element is a filter mounting structure of an air filter housing, and the gasket is then suitably configured to have a size and shape adapted to fit the gap between the filter frame and the mounting structure.

The sealing device can be included in an air filtration apparatus comprising the sealing device, a filter frame, and a filter housing, and wherein the sealing device is located in a gap between the filter frame and the filter housing so that the gasket members of the sealing device are in contact with the filter frame and the housing. The air filtration system can comprise an air filtration apparatus and a pressure source, which is connected to the intermediate space(s) of the sealing device, to allow the pressure source to maintain a set pressure difference towards the surroundings. The air filtration system can also suitably comprise a control sensor located between the pressure source and the surroundings, which control sensor is preferably configured to communicate with an evaluation device. A method of installing the above sealing device in an air filtration system may comprise the steps of positioning the sealing device in the gap between the filter frame and the filter housing; mounting the filter frame to the housing so that the gasket members of the sealing device are in contact with the filter frame and the housing; and connecting the channel to the pressure source to allow a pressure to be applied on the intermediate gasket space(s) of the sealing device.

As mentioned above the sealing device is configured to be connected to a pressure source adapted to apply a pressure on the intermediate gasket space. The pressure may be an overpressure or an underpressure, which means that the pressure is applied by the pressure source so as to create positive or negative pressure difference relative to the surroundings, i.e. outside of the intermediate gasket space. The pressure can suitably be applied by the pressure source such that the pressure difference between the intermediate gasket space and the surrounding is 50 Pa-1000 kPa, preferably 1 kPa-500 kPa.

As the gasket is comprised of two separate elongated gasket members, the intermediate gasket space is open toward the surfaces of the first and second elements, the application of a pressure to the intermediate gasket space will have the effect that if a leak should arise on either side of the gasket, the pressure within the intermediate gasket space will be affected, such as a leakage flow is pushed back if the applied pressure is an overpressure, or sucked into the intermediate gasket space if the applied pressure is an under pressure as compared to the pressure outside the gasket.

The pressure source can preferably be configured to continuously maintain a set pressure difference towards the surroundings to allow continuous improved leak tightness. The pressure source can be any suitable pressure or vacuum source, such as an air pump or a pressure or vacuum tank, or a centralized compressed air system.

As mentioned above, methods for leakage detection are available, for example according to the standards ISO 10648-2, EN12237 or EN1886. These methods generally include applying a pressure to the interior volume of the sealed enclosure or room to be leak tested, stabilising the pressure and monitoring any changes in the pressure on the volume during a test time period. A leakage detecting or monitoring device suitably comprises a leakage sensor positioned in a conduit between the pressure source and the intermediate gasket space. The leakage sensor is configured to be able to detect a pressure change within the intermediate gasket space, which is indicative of leakage. When the pressure source is connected to the intermediate gasket space, leakage detection can be available at all times, and can be applied also while the sealed enclosure or room to be tested is in use or operation. Thus, the leakage detection can be applied on the actual equipment to be used, including the seal of the gap during service. No substitute parts, such as blanking plates or the like, need to be used. The leakage sensor can be selected in accordance with the leak tightness requirement set for the sealed enclosure or room, to be able to detect unacceptable leaks. It can be an air flow sensor or a pressure sensor, for example a thermal airflow sensor, pressure drop measurement device for measurement over capillaries or orifices, rotating vane, vortex meter, or ultrasonic flow meter. The leakage monitoring device can further comprise a control sensor located between the pressure source and the surroundings, to allow to monitor that the pressure source is operating properly. The control sensor can be selected from the same types as the leakage sensor.

The leakage sensor can be configured to communicate with an evaluation device, such as a computer, to allow remote surveillance of the leakage monitoring. For example the sensor can include a transmitter forwireless communication with a receiver, orthe communication can occur via wired connection. The leakage monitoring device further advantageously comprises a backup pressure source arranged parallel to the pressure source, to minimize the risk of pressure failure. Monitoring may preferably be performed continuously by continuously applying pressure to the intermediate gasket space by means of the pressure source, and continuously obtaining the leakage detection values from a leakage sensor, and optionally also from a control sensor, and continuously comparing the leakage detection values with setpoint values. By continuously monitoring the leak tightness of the gap sealed by the sealing arrangement, a leak can be immediately detected, and accordingly no backtracking to an earlier leak tightness validation is needed. In the manufacture of products sensitive to contamination, such as pharmaceuticals, the process batch currently being produced when a leak is detected can be identified and be tagged to be checked or disposed of. This can lead to less waste, since only the tagged batch needs to be checked or disposed of, contrary to traditional intermittent leak tightness validation where all batches produced since the last successful validation may be compromised.

DESCRIPTION OF EMBODIMENTS SHOWN IN THE DRAWINGS

The subject-matter of the present disclosure will now be described with reference to the accompanying drawings, in which non-limiting example embodiments of the disclosure are shown. The subject-matter may, however, be embodied in other forms and should not be construed as limited to the herein disclosed embodiments. The disclosed embodiments are provided to fully convey the scope of the disclosure to the skilled person.

Figs, la and lb schematically illustrate a sealing device 1 comprising a gasket 5 configured to seal a gap 2 between a first element 3 and a second element 4. As shown in the drawing, the gasket is arranged to be located in the gap 2 and to be in contact with the first and the second elements during use. The gasket 5 comprises two elongated gasket members: an inner elongated gasket member 5a configured to surround an area A (not shown in Fig. 1) and an outer elongated gasket member 5b configured to surround the inner gasket 5a and the area A. Figs. 4a and 5a show examples of how the elongated gasket members surround the area A. The sealing device includes a carrier member 6, which extends along the length of the elongated gasket members, and to which the gasket members are attached to be held in position on a distance from each other so that an intermediate gasket space 8 is formed between them. A channel 7 connects the intermediate gasket space 8 with the surroundings, in the example of Fig. la arranged through the gasket member 5a, and in the example of Fig. lb through the gasket member 5b. When the channel 7 is arranged through the inner gasket member 5a, the channel will connect the intermediate gasket space with the side of the sealing device that is surrounded by the gasket, and when the channel 7 is arranged through the outer gasket member 5b, the channel will connect the intermediate gasket space with the side of the sealing device that is outside area surrounded by the gasket. In the following, the embodiments are illustrated with the channel directed toward the area surrounded by the gasket. However, all these embodiments may apply also to variants where the channel 7 is directed away from the area surrounded by the gasket. The channel is configured to be connected to a pressure source, to allow application of pressure on the intermediate gasket space 8 during use, as illustrated in Fig. 7.

Figs. 2a-c, 3, 4a and 4b schematically illustrate embodiments wherein the carrier member 6 is a frame 6a. The frame has a first surface 9' and a second surface 9", opposite to one another and extending between the two elongated gasket members. Thereby a first intermediate gasket space 8' is partially confined by said first surface 9', and a second intermediate gasket space 8" is partially confined by said second surface 9". In these embodiments the two elongated gasket members 5a, 5b are divided along their length, into an first gasket member portion 5a', 5b' and a second gasket member portion 5a", 5b", with the first gasket member portions 5a', 5b' attached to the first surface 9' of the frame, and the second gasket member portions 5a", 5b" attached to the second surface 9" of the frame 6. As shown the frame can be made to extend beyond the gasket member portions in a direction transverse to the length of the elongated gasket members so that it is exposed on the outside of the gasket. In the embodiments shown in Figs. 2a-c, the carrier member is in the form of a solid frame. In Fig. 2a, the channel 7 is formed through the solid frame, in the form of a through bore. In Fig. 2b, the carrier member is a continuous frame with no openings between the two intermediate gasket spaces formed on each side of the frame. Channels 7 are arranged through the gasket members on both sides of the frame to connect the two intermediate gasket spaces with the surroundings. In Fig. 2c, the carrier member is solid, but has an opening connecting the two intermediate gasket spaces, so that they can both be connected with the surroundings by means of a channel through one of the gasket members. The intermediate gasket spaces are thus connected each of the intermediate gasket spaces 8', 8" with the surroundings and being configured to be connected to a pressure source is arranged through the frame 6a.

Also, in the example shown in Figs. 4a and 4b, carrier is in the form of a solid frame 6a. The channel 7 connecting the intermediate gasket spaces 8 on each side of the frame is directed toward the surrounded area A.

In the example shown in Fig. 3, the carrier member is in the form of a frame having a hollow structure, where inner openings 10 are arranged in the first and second surfaces 9', 9" and an outer opening 11 is arranged in a portion of the frame extending beyond the first and second gasket member portions so that the outer opening 11 can be connected to a pressure source. In this case, the frame in its entirety acts as a channel connecting the intermediate gasket spaces with the surrounding.

Figs. 5a and 5b schematically illustrate an embodiment wherein the carrier member 6 is an open framework 6b extending between the elongated gasket members. The carrier member is not shown in Fig. 5a. In Fig. 5b the illustrated carrier member is a zig zag structure, and the two elongated gasket members 5a, 5b are attached to the carrier member so that portions of the open framework 6b are partially enclosed by the material of the two elongated gasket members 5a, 5b. The channel 7 connecting the intermediate gasket space 8', 8" with the surroundings and being configured to be connected to a pressure source is arranged through one of the two elongated gasket members.

Figure 6 illustrates how the sealing device 1 can be mounted between a filter 23 (first element 3) and a filter housing 24 (second element 4) in an air filtration apparatus, so as to seal the gap 2 between the filter frame and the filter housing. Thus, in this case the area surrounded by the elongated gasket members will be the surface of the filter.

Figure 7 shows schematically a leak tightness monitoring system, where a pressure source is connected to the intermediate gasket space (not shown in Fig. 7) via the channel 7. A pressure source 14 is adapted to apply a pressure on the intermediate gasket space 8. The pressure source is arranged in fluid communication with the intermediate gasket space 8 between the gasket members via a conduit 12. A leakage monitoring device 9 is included in the sealing arrangement and comprises a leakage sensor 13 positioned in the conduit 12 between the pressure source and the intermediate gasket space 8. The leakage monitoring device may further comprise a control sensor 16 located between the pressure source and the surroundings. The leakage sensor 13 comprises a transmitter configured to communicate with an evaluation device 17, which comprises a receiver to receive information from the leakage sensor or the control sensor. A backup pressure source 18 can be arranged parallel to the pressure source 14.

The person skilled in the art realizes that the present disclosure is not limited to the preferred embodiments described above. The person skilled in the art further realizes that modifications and variations are possible within the scope of the appended claims. Additionally, variations to the disclosed embodiments can be understood and effected by the skilled person in practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.

Claims

1. A sealing device (1) comprising a gasket (5) configured to seal a gap (2) between a first element (3) and a second element (4), wherein the sealing device is arranged to be located in the gap (2) and to be in contact with the first and the second elements (3,4) during use, characterised in that the sealing device comprises

- a gasket (5) comprising two elongated gasket members (5a, 5b), where an inner elongated gasket member (5a) is configured to surround an area (A), and an outer elongated gasket member (5b) is configured to surround the inner gasket (5a) and said area (A); and

- a carrier member (6), extending along the length of the elongated gasket members (5a, 5b) , and said elongated gasket members (5a, 5b) being attached to the carrier member so that they are held in position on a distance from each other so as to form an intermediate gasket space (8) between the gasket members (5a, 5b); and

- a channel (7) connecting the intermediate gasket space (8) with the surroundings and being configured to be connected to a pressure source, to allow application of pressure on the intermediate gasket space (8) during use.

2. The sealing device of claim 1, wherein the carrier member (6) is a frame (6a) having a first surface (9') and a second surface (9"), said second surface (9") being opposite to said first surface (9'), and said first and second surfaces extending between the two elongated gasket members (5a, 5b), whereby a first intermediate gasket space (8') is partially confined by said first surface (9'), and a second intermediate gasket space (8") is partially confined by said second surface (9").

3. The sealing device of claim 2, wherein at least one of the two elongated gasket members (5a, 5b) is divided along its length, into an first gasket member portion (5a', 5b') and a second gasket member portion (5a", 5b"), wherein the first gasket member portion(s) (5a', 5b') is/are attached to the first surface (9') of the frame, and the second gasket member portion(s) (5a", 5b") is/are attached to the second surface (9") of the frame (6), and wherein the frame extends beyond at least one pair of said first and second gasket member portions (5a', 5b'; 5a", 5b") in a direction transverse to the length of the elongated gasket members (5a, 5b).

4. The sealing device of claim 1, wherein the carrier member (6) is an open framework (6b) extending between the elongated gasket members, and wherein the two elongated gasket members (5a, 5b) are attached to the carrier member so that portions of the open framework (6b) are partially enclosed by the material of the two elongated gasket members (5a, 5b).

5. The sealing device of any one of claims 1-4, wherein the channel (7) connecting the intermediate gasket space (8', 8") with the surroundings and being configured to be connected to a pressure source is arranged through one of the two elongated gasket members (5a, 5b; 5a', 5b'; 5a", 5b").

6. The sealing device of claim 2 or 3, wherein the channel (7) connecting the intermediate gasket space (8', 8") with the surroundings and being configured to be connected to a pressure source is arranged through the frame (6a).

7. The sealing device of claim 6, wherein the frame (6a) is a hollow structure having one or more inner openings (10) arranged in said first and/or second surface (9', 9") and an outer opening (11) arranged in a portion of the frame extending beyond the first and second gasket member portions (5a', 5b'; 5a", 5b"), said outer opening (11) being configured to be connected to a pressure source.

8. The sealing device of any one of claims 1-7, wherein the channel (7) connecting the intermediate gasket space (8', 8") with the surroundings is arranged toward the area (A) surrounded by the gasket.

9. The sealing device of any one of claims 1-7, wherein the channel (7) connecting the intermediate gasket space (8', 8") with the surroundings is arranged away from the area (A) surrounded by the gasket.

10. The sealing device of any one of claims 1-9, wherein said first element is a filter frame of an air filter (23) and said second element is a filter mounting structure of an air filter housing (24), and the gasket is configured to have a size and shape adapted to fit the gap between the filter frame and the mounting structure.

11. An air filtration apparatus comprising the sealing device (1) of claims 1-10, a filter frame (23) of an air filter, and a filter housing (24) including a mounting structure, wherein the sealing device is located in a gap (2) between the filter frame and the mounting structure of the filter housing so that the gasket members of the sealing device are in contact with the filter frame and the mounting structure of the filter housing. 16

12. An air filtration system comprising an apparatus according to claim 11 and a pressure source (14), which is connected to the intermediate space(s) of the sealing device, said pressure source preferably being configured to maintain a set pressure difference towards the surroundings.

13. The air filtration system of claim 12, further comprising a control sensor (16) located between the pressure source and the surroundings, said control sensor (16) preferably being configured to communicate with an evaluation device (17).

14. A method of installing the sealing device (1) of claims 1-10 in the air filtration system of claim 12-13 comprising the steps of:

- positioning the sealing device (1) in the gap (2) between the filter frame (23) and the mounting structure of the filter housing (24);

- mounting the filter frame to the housing so that the gasket members of the sealing device are in contact with the filter frame and the housing, whereby the intermediate gasket space becomes confined by the gasket members, a surface of the filter frame and a surface of the filter housing; - connecting the channel (7) to the pressure source (14) to allow a pressure to be applied on the intermediate gasket space(s) (8; 8', 8") of the sealing device.