Intumescent cover for fire protection

Abstract

The invention relates to a fire protection blanket (1) which comprises a first layer (10) made of a fabric of a heat-resistant material, in particular a glass fabric or a meta-aramid fiber fabric and a second layer (11) made of an intumescent material such as silicone or other intumescent acrylic, epoxy or PVC material, said intumescent material containing graphite and / or silicate fillers and a fire protection device for cable trays using one or more of said blankets.

Description

Technical field

[0001] The invention relates to the field of protecting elongated devices such as cable trays or pipes by fire protection fabric and in particular by coating the cable trays with one or more intumescent fire protection blankets. Prior art

[0002] The protection of devices such as cable trays has been carried out since the 1980s using technical thermal insulation products with refractory fibers using alkaline earth alumina-silicate materials which are used in particular in high temperature industrial furnace installations for example for the heat treatment of steels or others. These insulating products have the particularity of having a very high melting point of the order of 1300 to 1450°C and very good mechanical strength, high resistance and low shrinkage almost up to their melting temperature.

[0003] An example of fire protection using an insulating fibrous material is known from document FR2973252 A1 in the name of the applicant. Another example is known from JP2008215625 A. Technical problem

[0004] However, for nuclear reactor buildings with high-pressure pipes, the use of fibrous products should be avoided because, in the event of a rupture of such a pipe, a powerful jet could destroy the protection of the cable trays and carry away the fibres which risk clogging the filters.

[0005] Furthermore, fire protection with insulating fibrous materials limits the dissipation of heat produced by power cables and requires ventilation devices which increase the weight and size of the system.

[0006] A protective device with plates arranged in a staggered pattern is known from document JP4748540B2. Statement of the invention

[0007] In view of this problem, the present application proposes a device for protecting one or more elongated elements by means of plates of a covering material according to the appended claims.

[0008] Other features and advantages are described below. Brief description of the drawings

[0009] Other characteristics, details and advantages of the invention will appear on reading the detailed description below, and on analyzing the attached drawings, in which: [ Fig. 1 ] is a schematic view of layers of a cover according to one embodiment of the present invention; [ Fig. 2 ] is a schematic side sectional view of a cable tray construction equipped with covers; [ Fig. 3 ] is a schematic side view in section of an embodiment of a cable tray equipped with covers arranged according to the invention; [ Fig. 4A] represents a first realization of separator; [ Fig. 4B ] represents a second realization of separator. Description of the embodiments

[0010] The drawings and the description below contain, for the most part, elements of a certain character. They may therefore not only serve to better understand the present invention, but also contribute to its definition, if necessary.

[0011] Reference is now made to the figure 1 .

[0012] The intumescent fire protection blanket 1 of the figure 1 comprises a layer 10 made of a heat-resistant fabric, in particular a glass fabric resistant to heat above 500°C or a heat-resistant aramid fiber fabric.

[0013] For aramid fiber fabrics, we prefer a fabric based on meta-aramid fibers, in particular (poly(metaphenylene isophthalamide), PA MPD-I) known under the brand name Nomex, whose heat resistance is lower than that of glass but which remains a second choice that may be used.

[0014] This layer is made to offer very good tensile strength depending on the warp or weft of the fabric as well as tear resistance while allowing it to be cut with scissors or cutter.

[0015] Inexpensive glass fabric is particularly well suited to this application and will be taken as a non-limiting example in the description below.

[0016] This glass fabric constitutes a support layer for a layer 11 of intumescent product such as an intumescent silicone material or an acrylic, epoxy or PVC intumescent material containing graphite fillers.

[0017] The glass fabric makes it possible to create a base layer that does not deform in its plane, which allows good cohesion to be maintained with the layer of intumescent material up to high temperatures, the glass fiber only becoming viscous at temperatures of around 800°C.

[0018] The glass fabric is preferably a fabric comprising 5 to 10 threads / cm in weft and warp, for which the threads are composed of 100 to 300 glass strands, the fabric having a surface mass of 400 to 800 g / m 2< .

[0019] The layer of intumescent material is made in the following example from a silicone material which crosslinks at room temperature but as seen above, an acrylic, epoxy or PVC intumescent material containing graphite or silicate fillers can be used.

[0020] This material may be in the form of a coating applied, for example, by a single or multi-pass coating process on the fabric layer possibly previously covered with a layer of bonding material 12 of the same chemical nature as the intumescent material.

[0021] Such a layer of bonding material 12 between the glass fabric and the layer of intumescent material is, according to the example, a layer of silicone bonding material which crosslinks at room temperature in the case of a silicone-based intumescent material, an acrylic material for an acrylic-based intumescent material, an epoxy material for an epoxy-based intumescent material, a PVC material for a PVC-based intumescent material.

[0022] The bonding layer is applied to the fabric, for example, by a coating process before the intumescent material layer is applied. This bonding layer allows the intumescent material to adhere better to the fabric. The bonding layer material is applied in a thin layer to the fabric, typically 100 to 300 g / m 2 < .

[0023] According to a preferred embodiment, the fabric is a glass fabric, the bonding layer is a silicone material and the intumescent material is silicone-based.

[0024] Returning to the layer of intumescent material 11, this material, in particular silicone, is a material loaded with a silicate or graphite base which allows it to swell in the event of a rise in temperature. This material, for its application, contains a catalyst to allow its crosslinking as well as a setting retarder to extend its setting time at room temperature. This allows easy application to the fabric without, however, disturbing the heating-accelerated crosslinking process for which the aim is to have the shortest possible setting time, typically of the order of a few minutes at around 140 to 180°C. Furthermore, since the intumescence of the intumescent material must not be triggered during the heating-accelerated crosslinking process, the dosage between the silicate base and / or expandable graphite is adapted according to the process used.

[0025] By convention, the outer face of the cover will subsequently be called the face comprising the fabric layer 10 and the inner face the face comprising the intumescent material because the face of the cover in contact with the object to be protected, for example a cable tray, is the face comprising the intumescent material and the outer face of the cover relative to the object to be protected is the face comprising the fabric.

[0026] The cover according to the example comprises on the external face on the fabric, a finishing layer 13 for which a silicone material or an acrylic finishing sealant is used which crosslinks at room temperature. This material can be a liquid material applied, for example, by a coating process and which is then allowed to crosslink. This finishing material makes it possible to make the fabric waterproof and airtight, washable and decontaminable. It is applied in a thin layer, typically 100 to 300 g / m 2 < .

[0027] Silicone, acrylic, epoxy or PVC materials containing graphite and / or silicate fillers may be of the polycondensation or polyaddition type. These are materials that are preferably crosslinkable at room temperature.

[0028] The manufacturing process starts with a roll of fabric of a width compatible with the coating ovens of a continuous production line which includes a station for applying the bonding material at room temperature, a station for coating this material and crosslinking by heating, a station for turning the material over to apply the finishing layer and heating it for crosslinking. The cover, a few meters wide, is then packaged in rolls, for example 500 meters long, to be delivered to the user who will cut sheets adapted to the elements to be protected.

[0029] The intumescent cover of the present application can be installed on cable trays or other elongated elements passing through premises such as pipes with its internal face of intumescent silicone material applied to said elongated elements and its external face washable on the outside.

[0030] Single-layer cut cover plates are shown in figure 2 which represents a longitudinal section of a cable tray where plates 1a, 1b are positioned juxtaposed on the upper and lower faces and on the side faces not shown.

[0031] Cover plates are sized according to the dimensions of the devices to be covered and, for example, plates with a width equal to that of the cable trays and plates with a width equal to the height of the cable trays can be made. The plates can be cut to a length of 1 m to 2 m and can be recut to fit the devices to be protected.

[0032] There figure 3 represents the improved configuration of the invention which leaves gaps between the layers to give space to the material when it swells under heat.

[0033] In this example, first layers of plates 3a and 3b are laid respectively on and under the cable tray, leaving first spaces 6 between them of a length such that the ends of these plates are covered by the ends of second layers of plates 4a, 4b overlapping the first spaces and themselves leaving second spaces 7 between them. The operation is repeated with a third layer of plates 3'a, 3'b overlapping the second spaces and separated from each other by third spaces 8 and a fourth layer of plates 4'a, 4'b separated by spaces 9. Thus, the spaces between the intumescent cover plates allow the intumescent material to expand under the action of the heat of a fire without significant swelling of the protection.

[0034] Furthermore, the stacked ends 5 with a length of the order of 5% to 20%, preferably 5% to 10% of the length of the plates will, for example, serve as areas for fixing the covers by metal ties or clamps.

[0035] The spaces between the cover plates can be left empty and are then filled with ambient air.

[0036] Alternatively, filling means such as separators 20, 21 adapted to hold the plates apart are arranged in the spaces between the plates to reinforce the coverage of the protected devices.

[0037] These filling means can be produced by openwork plates 20 such as honeycomb or partitioned plates or accordion separators 21 arranged in the spaces between the plates of the covering material.

[0038] They can be made of fusible or non-fusible material.

[0039] When the separator material is a fusible material, the resorption of this material will leave room for the swelling of the intumescent material layer of the plates when subjected to heat. Otherwise, the shape of the separators will allow the swelling of the intumescent material.

[0040] Cover plates are held onto cable trays in the traditional way, for example using metal clamps. They can surround several sides of the cable tray or be positioned face to face.

[0041] The invention is not limited to the examples shown and in particular more than four thicknesses of covers per face of the cable tray can be used.

Claims

1. An elongated element (2) such as a cable tray or pipes, covered by a fire protection device including cover plates provided with a cover material provided with an internal face positioned on the elongated element side including a layer (11) of intumescent material and provided with an external face including a layer of fabric (10) of a heat-resistant material, characterised in that it includes a plurality of said plates stacked in a staggered manner and comprising: - a first layer of said plates (3a and 3b) laid on at least one face of said elongated element(s) and disposed spaced apart from each other, leaving first spaces (6) therebetween; - a second layer of said plates (4a, 4b) laid on the first layer, overlapping the first spaces and disposed spaced apart from each other, themselves leaving second spaces (7) therebetween; - a third layer of said plates (3'a, 3'b) overlapping the second spaces (7) and disposed spaced apart from each other, themselves leaving third spaces (8) therebetween and; - at least a fourth layer of said plates (4'a, 4'b) overlapping the third spaces (8) and disposed spaced apart from each other, themselves leaving fourth spaces (9) therebetween; said spaces having a length such that the ends of the plates of said layers are stacked on top of each other, a central part of said plates overhanging said spaces, so as to have expansion zones of the intumescent material in the event of fire and good cooling of the elongated elements in normal use.

2. The elongated element (2) according to claim 1 for which said spaces are filled with ambient air.

3. The elongated element (2) according to claim 1 for which separating means are disposed in said spaces.

4. The elongated element (2) according to claim 3, for which said separating means are perforated plates (20) or accordion separators (21).

5. The elongated element (2) according to claim 3 or 4 for which the separating means are made of fusible material.

6. The elongated element (2) according to any one of the preceding claims, wherein said elongated elements are cable trays or pipes, the sheets of covering material being disposed on one or more faces of the cable trays or pipes and held by clamping means such as clamps, wire or the like.

7. The elongated element (2) according to any one of the preceding claims, for which the fabric is a glass fabric or a meta-aramid fibre fabric and the intumescent material is a silicone or an acrylic, epoxy or PVC intumescent material, said intumescent material containing graphite and / or silicate fillers.

8. The elongated element (2) according to any one of the preceding claims, for which said plates include a third layer of a bonding material (12) interposed between the fabric and the intumescent material.

9. The elongated element (2) according to claim 8 for which the bonding material (12) is of the same chemical nature as the intumescent material and of the polycondensation or polyaddition type adapted to promote the adhesion of the intumescent material to said fabric.

10. The elongated element (2) according to any one of the preceding claims, for which the fabric is coated on its side opposite the internal face with a silicone finishing layer (13) forming an external face of the cover which forms on the fabric an air-tight or water-tight layer which can be decontaminated by washing.

11. The elongated element (2) according to claim 10 for which said finishing silicone layer (13) is of the polycondensation or polyaddition type.

12. The elongated element (2) according to any one of the preceding claims for which the intumescent material (11) is of the polycondensation or polyaddition type.

13. The elongated element (2) according to any one of the preceding claims wherein said stacked ends (5) are of a length of 5% to 20% of the length of the plates.

14. A method for covering one or more elongated elements (2) such as cable trays or pipes, by means of plates of a covering material provided with an internal face intended to be positioned on the elongated element side including a layer (11) of intumescent material and provided with an external face including a layer of fabric (10) of a heat-resistant material, characterised in that it includes: - laying a first layer of said plates (3a and 3b) on at least one face of said elongated element(s) disposed spaced apart from each other to leave first spaces (6) therebetween; - laying a second layer of said plates (4a, 4b) on the first layer, overlapping the first spaces and disposed spaced apart from each other to leave second spaces (7) therebetween; - laying a third layer of said plates (3'a, 3'b) overlapping the second spaces (7) and disposed spaced apart from each other to leave third spaces (8) therebetween and; - laying at least a fourth layer of said plates (4'a, 4'b) overlapping the third spaces (8) disposed spaced apart from each other to leave fourth spaces (9) therebetween; said spaces having a length such that the ends of the plates of said layers are stacked on top of each other, a central part of said plates overhanging said spaces, so as to have expansion zones of the intumescent material in the event of fire and good cooling of the elongated elements in normal use.

15. A method for protecting from fire one or more elongated elements (2) according to claim 14, wherein said spaces are filled with ambient air.

16. The method for protecting from fire one or more elongated elements (2) according to claim 14 or 15 for which separating means are disposed in said spaces.

17. The method for protecting from fire one or more elongated elements (2) according to claim 16, for which said separating means are perforated plates (20) or accordion separators (21).

18. The method for protecting from fire one or more elongated elements (2) according to claim 16 or 17 for which the separating means are made of fusible material.

19. The method for protecting one or more elongated elements (2) according to any one of claims 14 to 18, for which the plates of covering material are disposed on one or more faces of the cable trays or pipes and held by clamping means such as clamps, wire or the like.

20. The method for protecting from fire one or more elongated elements (2) according to any one of claims 14 to 19, for which the fabric is a glass fabric or a meta-aramid fibre fabric and the intumescent material is a silicone or an acrylic, epoxy or PVC intumescent material, said intumescent material containing graphite and / or silicate fillers.

21. The method for protecting from fire one or more elongated elements (2) according to any one of claims 14 to 20, for which said plates include a third layer of a bonding material (12) interposed between the fabric and the intumescent material.

22. The method for protecting from fire one or more elongated elements (2) according to claim 21 for which the bonding material (12) is of the same chemical nature as the intumescent material and of the polycondensation or polyaddition type adapted to promote the adhesion of the intumescent material to said fabric.

23. The method for protecting from fire one or more elongated elements (2) according to any one of claims 14 to 22 for which the fabric is coated on its side opposite the internal face with a silicone finishing layer (13) forming an external face of the cover which forms on the fabric an air-tight or water-tight layer which can be decontaminated by washing.

24. The method for protecting from fire one or more elongated elements (2) according to claim 23 for which said finishing silicone layer (13) is of the polycondensation or polyaddition type.

25. The method for protecting from fire one or more elongated elements (2) according to any one of claims 14 to 24 for which the intumescent material (11) is of the polycondensation or polyaddition type.

26. The method for protecting from fire one or more elongated elements (2) according to any one of claims 14 to 25, wherein the plates are disposed such that said stacked ends (5) are of a length of 5% to 20% of the length of the plates.

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