GB2476345A

GB2476345A - A fire resistant passageway closure

Info

Publication number: GB2476345A
Application number: GB1019186A
Authority: GB
Inventors: Clifford Miles
Original assignee: FIRE AND SOUND Ltd
Current assignee: FIRE AND SOUND Ltd
Priority date: 2009-09-08
Filing date: 2010-11-12
Publication date: 2011-06-22
Also published as: GB0919803D0; GB0915675D0; GB201019186D0

Abstract

A fire resistant passageway closure for an aperture in a wall comprises a frame 20 which extends across the aperture which supports pair of cylindrical elements 27 of resilient intumescent material across the frame. The elements are arranged such that, upon insertion of an electrical or mechanical service pipe or cable 25, then the elements are held close to the pipe or cable to maintain a sufficiently fire safe seal. The cylindrical tubes may comprise rolled sheets of intumescent material and may be supported on an internal rod or spindle 51 by foam disc spacers 52 or helical spring.

Description

FIRE RESISTANT PASSAGEWAY FOR SERVICE ITEMS

Field of the Invention

The present invention relates to fire resistant passageway apparatus for services such as cabling between walls of buildings, an assembly comprising fire resistant passageway apparatus and a conduit and a method of providing a fire resistant passageway for a conduit. In particular, the present invention provides a closure or a fire resistant passageway for a conduit which enables cables to be provided and removed without affecting the fire rating of the apparatus.

Backaround to the Invention

All buildings built in the United Kingdom must conform to fire protection standards. The standards are more onerous to satisfy in the case of hotels, business premises and all commercial buildings in general, than for residential premises. One aspect that United Kingdom legislation covers, mirrored in the legislation of other countries to a similar level, is the closure of apertures between adjacent rooms, partitions comprising floors, ceilings and walls. The use of brick work, block work and other partitions for supporting structures is almost universal; when apertures or conduits are made within the partitions, then opportunities for the spread of fire are provided; airflow is possible through an untreated aperture. In the United Kingdom, building regulations state that fire-stopping elements must be provided to prevent the spread of fire.

Apertures and conduits are arranged to pass through walls and floors whereby to provide access for electrical cabling, audio-visual control and communications cabling between rooms of houses, hotels, restaurants, exhibition halls and other venues, whereby to connect electrical apparatus, communications access by hard wiring in different rooms. Equally, conduits are prevalent in buildings for flues, water pipes and the like.

Typical fire-stopping elements comprise the packing of apertures with intumescent compounds and the use of pipe collars. When an aperture is defined and service lines have been inserted, then intumescent materials or the like can be inserted; this can be difficult to apply uniformly in many situations whereby the required potential fire-stop properties of the plaster are not created; the compound is not applied to a uniform degree; cracks develop whereby the fire-stop properties are limited and not to a required standard.

Pipe collars comprise flanges which surround pipes, electrical conduits and the like -an inside surface of the collar comprises an inturnescent compound which expands under elevated temperature conditions. A typical activation temperature is around 180°C. The intumescent compound expands under such conditions whereby to seal around the aperture, preventing further passage of air and any other gases, helping to reduce the spread of fire.

Intumescent substrates, when heated above their temperatures of intumescence, swell to several or many multiples of their original volume.

Intumescent powders can be mixed with a thermoplastic material and subsequently utilised in moulds to form articles which, in case of fire, swell to close apertures, between a service conduit and an aperture defined within a floor, wall or partition.

As will be appreciated, such conduits may pass through fire combustible floors or walls or other fire resistant barriers. The passage of a flue through a combustible floor may reduce the integrity of the combustible floor. In general, floors should have a fire rating of 30 minutes, this is the time taken for a fire to penetrate the floor. The passage of the conduit may thereby enable a fire in one room to spread relatively quickly to an adjacent room and for the floor not to have a sufficient fire rating.

Conduits are prevalent in buildings for flues, water pipes and the like. Flues may be concealed within an enclosure, for example within a box wall, to visually conceal the flue which may otherwise be visible. In particular, flues are generally concealed in domestic properties in bedrooms etc. Since the flue is arranged to contain and guide hot gases, the flue naturally becomes hot.

Accordingly, as the flue passes through a floor or wall GB 2216220 provides a fire damper for sealing, in the event of fire, a penetration in a fire-resistant wall for the passage of a service e.g. pipe or cable and comprises a number of segments each consisting of layered strips of intumescent material packed and contained in sheaths of extruded PVC which are arranged coaxially with the conduit axis. End plates are secured to the wall by expansion bolts.

This prior device is suitable for conduits which are fixed; the arrangement is constructed such that components are fitted around a conduit such as a flue, water service pipe etc.. Such systems cannot, however, be employed around cables, pipes and the like which are inserted subsequently and or inserted on a temporary basis. Whilst small bags containing intumescent beads are known which can be placed in apertures in walls, they will tend to lie at a low point of the conduit and can easily be moved out of the way. Importantly, buildings and fire regulations are becoming such that it is becoming difficult for buildings with conduits for audio-visual cables and the like to satisfy building regulations (necessary for public events to be held) with such known solutions.

US2006138251 and GB12391173 (3 Strahl) teach of an opening closure comprising curvilinear plates of intumescent material supported by biasing means comprising a backing plate arranged axially through the opening and possibly further spring biasing means and one curved sprung members and provides a complex solution. US200637264 (Paetow et al) teaches of a rectilinear aperture provided with closely spaced parallel strips therein, the strips being relatively displaceable in a sliding fashion whereby to enable conduit to be placed through the aperture.

Object to the invention The present invention seeks to overcome at least one problem associated with the prior art. The present invention seeks to provide an intumescent closure for a penetration seal, operable to close conduits between rooms in buildings. The present invention also seeks to provide an intumescent closure adaptable to close conduits for the temporary provision of cabling between rooms in buildings and to provide a fire resistant barrier whether pipes and cables are in place or not.

Summary of the Invention

Generally, the present invention provides a fire resistant passageway closure for an aperture within a wall, the closure being defined by a frame which extends through the wall and across the aperture, the frame supporting at least a pair of opposed elements of cylindrical tubes of intumescent material within across the frame, the elements being operable, in a first state, to close the aperture and, in a second state, upon insertion of a services penetration item between the opposed elements, to close the aperture, the elements resiliently abutting against or closely proximate to the services penetration item, operable upon attaining a temperature of intumescence of the material to fully occlude the opening, and any gaps between, whereby to provide sufficient fire resistance qualities to the wall aperture.

In accordance with a first aspect of the invention, there is provided a fire fire resistant passageway for service items closure for an aperture within a wall, the closure being defined by a frame for placement within the aperture, the frame defining an opening and supporting at least a pair of opposed elements of cylindrical member of intumescent material internally across the frame, the elements being operable to resiliently close the opening, independently of the presence or absence of service penetration items therethrough, the cylindrical members comprising intumescent material. The passageway is operable upon attaining a temperature of intumescence of the material to fully occlude the opening, and any gaps between, thereby preventing any passage of air and smoke from one side of the closure to another, and providing sufficient fire resistance qualities to the wall aperture.

The passageway closure conveniently comprises resilient intumescent elements.

These can comprise least two generally circularly cylindrical tubes of intumescent material, which are retained in the frame and the intumescent material can be displaced to allow the passage of a cable or pipe services item therethrough. Other shapes are possible, so that the intumescent cylinders are rectangular or oval in cross-section. The cylindrical tubes of intumescent material can conveniently be filled with resilient material such as flame retardant plastics foam attached to a side wall of the casing.

Conveniently, the intumescent material is resilient. Typically the material is between 1 and 8mm thick. The intumescent material can be sheathed with a fabric shroud, conveniently formed from a material that is flexible yet can allow expansion of an intumescent material, such as aluminised glass cloth.

The intumescent cylinders can comprise tubes, the tubes being packed with resilient members, foam spacers and or spindles. Helical spring supporting means may be provided. The tubes can have slits arranged through the intumescent material.

In accordance with a preferred system in accordance with the invention, the resilient intumescent material comprises at least two generally cylindrical tubes of intumescent material, which are retained in the frame and the intumescent material can be displaced to allow the passage of a cable or pipe services item therethrough. The cylindrical tubes of intumescent material can conveniently be attached to a side wall of the casing. The frame conveniently is provided with upstanding edge members or lips whereby to assist in the retention of the cylinders of intumescent material.

Brief descriltion of the Figures Some preferred embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, of which: Figure 1 shows the use of two pipe collars either side of a partition wall; Figures 2a -2 c show an arrangement in accordance with a first aspect of the invention; Figures 3 (i) & (ii) show a basic intumescent member; Figure 3a shows a basic inturnescent member with a shroud; Figures 4a & 4b show an intumescent member before and after a fire event; Figure 5 show four arrangements of four intumescent cylinders within a frame; Figure 5a -5c show how the intumescent material is spaced within a frame; and, Figure 6 shows two adjacent slotted intumescent members.

Detailed Descriltion of the Preferred Embodiments There will now be described, by way of example only, the best mode contemplated by the inventor for carrying out the present invention. In the following description, numerous specific details are set out in order to provide a complete understanding to the present invention. It will be apparent to those skilled in the art, that the present invention may be put into practice with variations of the specific.

Referring to Figure 1, there is shown the use of two fire-stop pipe collars either side of a partition. A typical pipe collar 12 will be two-hour fire rated and is suitable for fitting to concrete, masonry, porous concrete or stud wall constructions. Fire-stop pipe collars consist of a powder coated steel sleeve containing a flexible graphite based intumescent liner manufactured to suit the pipe-work to be fire-stopped. Integral toggle connectors, for example, are opened up and the collar is simply fitted around the plastic pipe. The toggle fastening means are closed and the collar is pushed flush to the surface of the wall or underside of floor. The collar is then securely fastened to the structure by means of fire resistant fixings threaded through fixing tabs. Any gaps of up to 25mm wide around the pipe work should be filled with an intumescent sealant. For gaps greater than 25mm, a fire stop compound can be used.

When exposed to the heat of a fire, the intumescent material contained in fire-stop pipe collars will expand and exert a high pressure on the melting plastic pipe, to cause the opening to be closed off and thus preventing the spread of fire from one compartment to another. However, as discussed above this sort of intumescent device is inappropriate for electrical and mechanical service penetration items.

Figures 2a -2 c show a basic arrangement in accordance with a first aspect of the invention. Figure 2a shows an empty frame 20 and comprises a generally square metallic casing having four walls. The casing can comprise a steel such as a mild steel (EN400), suitably finished, having a thickness of 1.8 mm or so -although the thickness may vary, dependent upon any load that may be imposed due to a particular installation -for example the aperture closure may need to provide a strength similar to a lintel, as employed over door and window frames to prevent a weight of bricks etcetera from weighing down and deforming the closure. The frame is placed within an aperture defined in a wall and attached and sealed to the wall so that no gaps or spaces are defined between the wall and frame. The walls of the frame 21 -24 are edged with a lip 25; for a 30 cm square aperture, the lip would extend about 2.5cm, whereby to provide an element of tracking for the intumescent elements as shall now be described.

Referring now to Figure 2b, the intumescent element 27 inserted within the frame 20 comprise generally cylindrical bodies. The cylinders may comprise solid cylinders. For example, they can comprise a rolled-up intumescent sheet material, with a sufficient overlap to enable the rolled up portion to be fastened together. The sheet material is conveniently of a 3 -8mm thickness, material being resilient having a resinous binder which provides elasticity, as is commercially available based, with an expansion ratio of in the range of 20:1 - 50:1, preferably in the range 30:1 -50:1. The intumescent temperature is conveniently in the range, 150°C -250°C. Indeed, as shown in this simple embodiment, the invention can comprise a square casing or frame within which just first and second generally circularly cylindrical members 27 extending from first 21 and second 23 oppositely directed inner walls of the case are fastened to respective oppositely directed third 22 and fourth 24 inner walls of the case, by screw fastener means, rivets or similar 28.

The sheet inturnescent material can comprise a graphite-based intumescent strip such as that available from Intumex Inc or Gluske GmbH which provides Kerafix strip, which is readily available in a range of thicknesses from 0.8 - 3.0mm, although sheets of greater thicknesses can also be obtained. Products such as these can typically expand in volume 30-fold or more, as determined by their expansion ratio. At an intumescent activation temperature, for example 170°C, expansion will occur. In the case of a closure in accordance with the invention, in the event there is a gap between cylindrical elements, then due to the presence of heat the elements will expand, sealing gaps therebetween and with respect to the casing 20, thereby preventing any passage of air and smoke from one side of the closure to another. The cylinders can comprise a number of profiles in plan view, but are conveniently circularly cylindrical. The cylinders can be solids, but resilience must be provided for to enable services penetration.

Figure 2c shows an example of the first embodiment with service cables 290, 291. Figure 3 shows an oblong sheet of intumescent material with a first dimension corresponding to the inside distance of the casing 20 within which the intumescent material is to be inserted, the sheet being flat (i) and then rolled into a generally circular cylinder or tube (ii). With reference to Figure 3a, the overlap portion 29 can be attached to each other and the casing (not shown) by means of screw-fastening means 28.

Referring now to Figure 3a, a shroud 30 conveniently surrounds the cylindrical intumescent material 31, which in the simple version is also connected with the intumescent material to opposite walls of the casing (not shown), by screw-fastening means or similar. The shroud is conveniently made of a material that is flexible yet can allow expansion of an intumescent material within, such as a glass cloth in particular a 400kgm3 Aluminised Satin finish Glass cloth has been found to provide sufficient flexibility yet contain the intumescent material following expansion. In a simple version an excess of material is folded over, whereby it allows a controlled expansion of the intumescent material upon exposure to heat above it activation temperature. The glass cloth may be pleated in the alternative. Conveniently, the glass cloth is adhered by suitable adhesive to the outside surface of the intumescent element. Figures 4a and 4b show how a pleated glass cloth surrounds an intumescent element before and after a fire event, where the intumescent material substantially fills the inside of the glass cloth shroud. The purpose of the glass cloth is to ensure that the intumescent material does not intumesce outwardly of the closure casing whereby to prevent the formation of a gas tight seal in the event of a fire. In the alternative, a glass-or Kevlar-reinforced intumescent sheet may be employed to enable the general shape of the cylindrical shape of the intumescent material to be retained, whereby to enable closure to be realised in a fire event. The inside of the intumescent cylinders can be filled with resilient stuffing that is optionally intumescent.

It will be appreciated that the cylindrical elements can be of a maximum size, determined by the width of the closure and the thickness of the intumescent material. For a 15 cm aperture defined by a casing, then the two cylindrical elements of 3 mm intumescent material would be able to expand to 360 mm (4 x 30 x 3) -however, it would be prudent to take into account that not all the intumescent material may be subjected to a temperature corresponding to an intumescent activation temperature. Further layers of intumescent material may be provided to provide a further level of security. Whilst circularly cylindrical members can easily and simply be produced, the cylindrical members can be formed such that they are square or rectangular in section. This is of advantage where a generally smooth outer surface is required, especially when the closure is not in use.

Figure 5 shows four different types of achieving closure across a rectangular aperture in plan view. Where the width of an aperture is considerably wider than the diameter of two intumescent cylindrical bodies (which may be of a general oval shape), it is appropriate to provide three or more cylindrical bodies. The cylindrical tubes are shown as being of square and oval in cross-section, and are attached to a side wall of the frame at attachment pints 28. Where the width of an aperture is wider than the diameter of two intumescent cylindrical bodies, it can be appropriate to provide a separate dividing wall within the frame between sets of pairs of cylindrical bodies, optionally with lips or edge frame portions, to ensure that the cylindrical bodies are restrained in position upon intumescence.

Where there are three cylindrical elements, the third and further cylindrical element can include a support element 51 fixed to or comprising part of the casing and about which the cylindrical intumescent material is attached. The frame may be arranged such that the cylindrical elements lie vertically or horizontally; for each pair of co-operating intumescent elements, the separate elements can be formed of different cylindrical shapes and the different elements can provide different degrees of resilience.

Conveniently, the intumescent elements comprise cylindrical tubes, with the outside sheet of intumescent material 31 maintained a distance away from a central support element such as a rod or spindle 51, by spacer means 52. The tubes can be formed as such or manufactured by the forming of a rectangular sheet to provide a cylindrical tube, with sufficient overlap so that the overlapping edges can be attached by rivet, thread, pins, screwbolt or otherwise. If the intumescent material is not elastic or not sufficiently elastic, then separate resilient means can be provided. In Figure 5a, the spacers comprise foam discs 52, which are retained along the rod 52 in a spaced apart fashion. The rod or spindle 52 is fixedly retained, by welding, screw fastening means or otherwise, to the first and second walls of the casing. Alternatively, the rod or spindle may be slidingly retained within a channel (not shown) whereby the cylindrical element may be displaced in a plane parallel to the plane defined by the lips of the aperture. The rod or spindle if circularly cylindrical may also be retained -additionally or alternatively -for rotation, which may assist with the passage of service items as they are passed through the closure, the spindle supporting the circularly cylindrical intumescent elements, by being stuffed, supported by discs etc..

To enable the shape of the generally cylindrical shape to be maintained, the intumescent sheet walls may be positioned by foam discs 52 of, say 1cm thickness and spaced every 5cm along the support rod or spindle, as shown in Figure 5a. Alternatively, the foam could completely fill the interior of the intumescent cylinder. In the occurrence of a fire event, then the foam -which would be of a fire retardant composition -would melt (at a temperature below the activation temperature of the intumescent element) and expanding intumescent material would take its place. A helical spring could also be used instead to perform the same function, as shown in Figure Sb. In a still further alternative, a spring of a three-dimensional sinusoid form may perform the same function, as shown in Figure Sc. A support rod 51 may be provided to prevent outward movement of the intumescent material as the material expands. Equally, if the material is secured otherwise to the frame, then such internal rods or tubes would not be necessary since the intumescent material would not have a tendency to bow or not bend outwardly. It has been found that having the intumescent material completely filling the inside of the member is particularly advantageous.

Figure 6 shows two adjacent cylinders 61, 62 with slits 63 arranged perpendicular to an axis of the cylinder, the cuts conveniently comprising angular swathes between 1800 -2700 of the cylinder, and can be considered as being akin to a toast rack, enabling selective passageway of services conduits therethrough. In use, services cabling 64 will depress only a limited part of the intumescent material, reducing the size of gaps between the cylindrical elements and the services conduits. The spacing of the cuts can be regular or varied, but is conveniently similar to the width of typical services conduits. The slits need not be perpendicular to the axis of the cylinder.

The present invention simply provides a closure assembly that provides access for service pipes that are typically provided on a temporary basis (but may in fact be permanent or semi-permanent. The fire rating of a wall is not compromised by the presence of a closure in accordance with the invention.

Further advantages of the present invention include the following; simple installation; formed-in place shrouding; a system which is easily assembled and maintenance free, is unaffected by humidity and is suitable for making good around most types of service penetrations.

In a typical installation, the number of frame members is conveniently two, with one frame being provided on opposite sides of an aperture through a wall.

It is to be noted that many apertures through walls are defined by the absence of a breeze-block and therefore internal frame members can be manufactured of standard dimensions. The frame, is conveniently manufactured form a mild steel, the exact thickness being dependent upon a required strength of the closure -it will be appreciated that in certain situations the closure will need to be placed in a freshly opened wall opening; the opening of the wall may have compromised the security of the wall and the closure frame may well enable the wall to be strengthened, such that it acts, at least in part, as a lintel. Equally, provision can be made for custom internal frame members. Internal frame members are conveniently provided with intumescent flashings which enable a secure seal to be made with the internal walls of the aperture.

The intumescent material must not expand at too low a temperature since this would result in the ventilation being closed off during normal operating temperatures created by cables which run at elevated temperatures. The fire resistant means may be arranged, once activated, to prevent fire passing through the fire resistant passageway apparatus for a predetermined length of time. The intumescent material is arranged to prevent or inhibit a fire passing through the opening. Preferably the frame is attached to or comprises a plate, which in use, is fixedly located to a first side of the wall. Alternatively the frame is attached to or comprises a seal which can abut inside faces of an aperture.

The device can simply and reliably accommodate several cables and/or pipes.

Importantly, the penetrating services can be removed and re-installed several times. This is of particular benefit where, for example, in buildings such a theatres, halls and exhibitions are situated, where external service providers need to install, on a temporary basis, external facilities, such as a-v cabling, three-phase power, fluids such as gasses such as carbon dioxide of special effects etc. Importantly, the provision of closure devices in accordance with the present invention enables the provision of cables and pipes can vary in size and shape without adverse effect to the fire resistance of a building.

The casing may be fabricated such that it can be split across two walls, whereby to be fitted about pre-existing and immovable or relatively immovable service conduits, the casing is split, put in place and connected to form a rigid casing, once installed within an aperture, about said pre-existing service conduits. In the event that the closure is of a depth that is small with respect to the aperture, then two relatively narrow closure units may be placed at either end of an aperture. In the event that two closure units are present, it may be advantageous to have the cylindrical intumescent units of the respective closure units arrange perpendicularly with respect to one another.

Claims

Claims 1) A fire resistant passageway for service items for an aperture within a wall, the closure being defined by a frame for placement within the aperture, the frame defining an opening and supporting at least a pair of opposed elements of cylindrical members of intumescent material internally across the frame, the elements being operable to resiliently close the opening, independently of the presence or absence of service penetration items therethrough, the cylindrical members comprising intumescent material.
2) A fire resistant passageway according to claim 1, wherein the resilient intumescent elements comprise cylindrical tubes of intumescent material, which are retained in the frame and the intumescent material can be displaced to allow the passage of a cable or pipe services item thereth rough.
3) A fire resistant passageway according to claim 2, wherein the intumescent elements comprise generally circularly cylindrical tubes.
4) A fire resistant passageway according to claim 2, wherein the intumescent material is between 1 and 8mm thick.
5) A fire resistant passageway according to any previous claim, wherein the intumescent material is resilient.
6) A fire resistant passageway according to any previous claim, wherein adjacent cylindrical members have different cylindrical sections.
7) A fire resistant passageway according to any previous claim, wherein the intumescent material is sheathed with a fabric shroud.
8) A fire resistant passageway according to claim 7 wherein the shroud is made of a material that is flexible yet can allow expansion of an intumescent material.
9) A fire resistant passageway according to claim 8 wherein the shroud comprises aluminised glass fibre.
10) A fire resistant passageway according to any one of claims 1 -9 wherein the intumescent cylinders comprise tubes, the tubes being packed with resilient members.
11) A fire resistant passageway according to any one of claims 1 -101 wherein the intumescent cylinders comprise tubes having a linear axis, the tubes having spaced apart slits arranged through the intumescent material.
12) A fire resistant passageway according to claims 11, wherein the slits are defined about an arc of between 1000 -270° relative to said axis and lie in a parallel spaced apart relationship.
13) A fire resistant passageway according to claim 12 wherein the spacing between the pairs of adjacent parallel slits are the same.
14) A fire resistant passageway according to any one of claims 1 -9 wherein the intumescent cylinders comprise tubes, the tubes being supported with a spindle with resilient discs operable to space the intumescent tube from the spindle.
15) A fire resistant passageway according to any one of claims 14, wherein the spindles and intumescent tubes are mounted for rotation with respect to the frame.
16) A fire resistant passageway according to any one of claims 1 -9 wherein the intumescent cylinders comprise tubes, the tubes being supported by means of a helical spring.
17) A fire resistant passageway according to any one of claims 1 -14, wherein the intumescent material has an intumescent expansion ratio of in the range of 20:1 -50:1.
18) A fire resistant passageway according to any one of claims 1 -14, wherein the intumescent material has an intumescent temperature in the range, 150°C -250°C.
19) A method of closing an opening comprising the fixing of one or more devices in accordance with any one or more of claims 1 -18 to or within an aperture within a wall whereby to provide a fire resistant closure.