FR3101552A1 - INTUMESCENT FIRE PROTECTION COVER - Google Patents

Abstract

The invention relates to a fire protection blanket (1) comprising a first layer (10) consisting of a fabric of a heat-resistant material, in particular a glass fabric or a fabric with meta-aramid fibers and a second layer (11) consisting of an intumescent material such as a silicone or other acrylic, epoxy or PVC intumescent material, said intumescent material containing graphite and/or silicate fillers and a cable tray fire protection device using one or more of said covers. Figure 1

Description

INTUMESCENT FIRE PROTECTION BLANKET

The invention relates to the field of the protection of 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 covers.

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

An example of fire protection using an insulating fibrous material is known from document FR2973252 A1 in the name of the applicant.

Technical problem

However, for nuclear reactor buildings with high-pressure pipes, the use of fibrous products should be avoided because, in the event of such a pipe breaking, a powerful jet could destroy the protections of the cable trays and cause the fibers that may clog the filters.

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

In view of this problem, the present application proposes a cover suitable for covering cable trays, pipes or other equipment to be protected from fire comprising a fabric forming a support for an intumescent product and more particularly a fire protection cover which comprises a first layer consisting of a fabric of a material in particular a glass fabric resistant to heat above 500°C or a fabric with meta-aramid fibers and a second layer consisting of an intumescent material such as a silicone or other acrylic, epoxy or PVC intumescent material, said intumescent material containing graphite and/or silicate fillers.

An advantage of the invention is that before the intumescence, the thermal conductivity of the material is high and its thickness lower than the fibrous devices which allows cooling of the cables or pipes covered by the blankets by conduction much greater than for wool-based thermal insulation systems, which eliminates the need for ventilation devices and reduces the weight and bulk of the system.

Advantageously, a third layer of an attachment material is interposed between the first layer and the second layer.

The attachment material is in particular a material of the same chemical nature as the intumescent material.

It is preferably of the polycondensation or polyaddition type and is suitable for promoting the adhesion of the intumescent material to the first layer. It can be a crosslinked material at room temperature.

To make the product washable and airtight or watertight and decontaminable by washing, the first layer is preferably coated on its side opposite to the second layer with a finishing layer forming an outer face of the cover. The finishing layer is advantageously made with a silicone material.

The finishing silicone layer is advantageously made from a material of the polycondensation or polyaddition type. It can be a crosslinked material at room temperature.

The intumescent material is advantageously of the polycondensation or polyaddition type and provides fire protection by modifying its thermal properties during its expansion. It can be a crosslinked material at room temperature.

The present application also relates to a device for protecting one or more elongated elements comprising one or more covers as defined above being positioned on said elongated elements.

According to this device, a plurality of said covers can be juxtaposed on said elongated elements, a plurality of said covers can be arranged in superposed or alternate multilayers on said elongated elements.

1. - une première couche de plaques de couvertures posées sur au moins une face du chemin de câble en laissant des premiers espaces entre elles ;
2. - une deuxième couche de plaques de couvertures posées sur la première couche, chevauchant les premiers espaces et laissant elles-mêmes entre elles des deuxièmes espaces ;
3. - une troisième couche de plaques de couvertures chevauchant les deuxièmes espaces et séparées entre elles par des troisièmes espaces et ;
4. - au moins une quatrième couche de plaques de couvertures chevauchant les troisièmes espaces et séparées entre elles par des quatrièmes espaces.

Les couvertures dans ce cas sont déposées de sorte que lesdits espaces sont d’une longueur telle que les extrémités des plaques desdites couches sont empilées les unes sur les autres.According to an advantageous mode, a plurality of cover plates are deposited in staggered rows, the device comprising:

1. - A first layer of cover plates placed on at least one side of the cable tray, leaving first spaces between them;
2. - A second layer of cover plates placed on the first layer, overlapping the first spaces and themselves leaving second spaces between them;
3. - A third layer of cover plates overlapping the second spaces and separated from each other by third spaces and;
4. - At least a fourth layer of cover plates overlapping the third spaces and separated from each other by fourth spaces.

The covers in this case are laid so that said gaps are of such length that the ends of the plates of said layers are stacked on top of each other.

These ends can in particular form areas for fixing the covers by metal ties or clamps.

This embodiment makes it possible in particular to have zones for the expansion of the intumescent material in the event of fire and good cooling of the cable trays in normal use.

Said elongated elements are in particular cable trays or pipes, the covers being arranged on all the faces of said cable trays or pipes and held by clamping means such as clamps, wire or other.

The covers made with the materials of the present application have the advantage of being light and flexible and of not risking projecting fibers which could clog filters in the event of deterioration of the protections of the cable trays in the case of blowing by a steam jet or other.

Other characteristics, details and advantages of the invention will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

is a schematic view of layers of a cover according to the present application;

is a schematic cross-sectional side view of a first embodiment of cable tray fitted with the covers of the application;

is a schematic cross-sectional side view of a second embodiment of cable tray fitted with the covers of the application;

is a schematic cross-sectional side view of a third embodiment of cable tray fitted with the covers on demand.

is a schematic cross-sectional side view of a fourth embodiment of cable tray fitted with the covers on demand.

The drawings and the description below contain, for the most part, certain elements. They may therefore not only be used to better understand the present invention, but also contribute to its definition, if necessary.

Reference is now made to Figure 1.

The intumescent fire protection cover 1 of FIG. 1 comprises a layer 10 consisting of a heat-resistant fabric, in particular a glass fabric resistant to heat above 500° C. or an aramid fiber fabric resistant to heat.

For aramid fiber fabrics, a fabric based on meta-aramid fibers and in particular (poly(metaphenylene isophthalamide), PA MPD-I) known under the Nomex brand, whose heat resistance is less than glass but which remains a second choice possibly usable.

This layer is made to offer very good tensile strength according to the warp or weft of the fabric as well as to tearing while allowing it to be cut with a scissor or cutter.

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

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.

The glass fabric makes it possible to produce a base layer which does not deform in its plane, which makes it possible to maintain good cohesion with the layer of intumescent material up to high temperatures, the glass fiber only becoming viscous at temperatures of the order of 800°C.

The glass fabric is preferably a fabric comprising 5 to 10 yarns/cm in weft and warp, for which the yarns are composed of 100 to 300 strands of glass, the fabric having a surface density of 400 to 800 g/m².

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

This material can be in the form of a coating applied, for example, by a single or multi-pass coating process on the fabric layer optionally previously covered with a layer of gripping material 12 of the same chemical nature as the intumescent material.

Such a layer of adhesion material 12 between the glass fabric and the layer of intumescent material is, according to the example, a layer of silicone adhesion material that crosslinks at room temperature in the case of an intumescent material based on silicone, 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.

The tie layer is deposited on the fabric, for example by a coating process before laying the layer of intumescent material. This grip layer allows better grip of the intumescent material on the fabric. the tie coat material is applied in a thin layer to the fabric, typically 100 to 300 gsm.

According to a preferred embodiment, the fabric is a glass fabric, the grip layer is a silicone material and the intumescent material is silicone-based.

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 enable its cross-linking as well as a setting retarder to lengthen its setting time at room temperature. This allows easy application on the fabric without however disturbing the process of accelerated crosslinking by heating for which it is sought to have the shortest possible setting time, typically of the order of a few minutes at around 140 to 180°C. On the other hand, as the intumescence of the intumescent material must not be triggered during the process of crosslinking accelerated by heating, the dosage between the silicate base and/or expandable graphite is adapted according to the process used.

By convention, one will subsequently call the outer face of the cover the face comprising the layer of fabric 11 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 path cable is the side comprising the intumescent material and the outer side of the cover with respect to the object to be protected is the side comprising the fabric.

The cover according to the example comprises on the outer face on the fabric, a finishing layer 13 for which a silicone material or an acrylic finishing mastic crosslinking at room temperature is used. 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 the fabric waterproof and airtight, washable and decontaminable. It is applied in a thin layer, typically 100 to 300 g/m².

The silicone, acrylic, epoxy or PVC materials containing graphite and/or silicate fillers can in particular be of the polycondensation or polyaddition type. They are preferably crosslinkable materials at room temperature.

The manufacturing process starts with a roll of fabric with a width compatible with the coating ovens of a continuous manufacturing line which includes a station for applying the adhesion material at ambient temperature, a station for coating this material and crosslinking by heating, a station turning over the material to apply the finishing layer and proceed to its heating for its 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.

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 washable external face on the external face.

A first embodiment consists in arranging cover plates cut out in a single layer as in FIG. 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.

In a second embodiment of Figure 3 which also shows a longitudinal section of a cable tray, the plates 1a, 1'a on the upper face of the cable tray and 1b, 1'b on the lower face of the cable tray as well as on the side faces of the cable tray are superimposed in two or more layers.

In a third embodiment according to Figure 4 which also shows a longitudinal section of a cable tray, the plates are alternated in two layers 1a, 1c on one side and 1b, 1d on the other side on the lower faces and upper as well as on the side faces.

The covers are held on the cable trays in the traditional way, for example by means of metal clamps. They can surround several faces of the cable tray or be positioned face by face.

The cover plates are dimensioned 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 produced. The plates can be cut to have a length of 1m to 2m and can be cut to fit the devices to be protected.

The example in Figure 5 is an improved configuration that leaves gaps between the layers to give space to the material when it expands under heat.

In this example, first layers of plates 3a and 3b are placed respectively on and under the cable tray, leaving first spaces 6 between them of such a length 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 expansion of the intumescent material under the action of the heat of a fire without noticeable swelling of protection.

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 zones for fixing the covers by metal ties or clamps.

The invention is not limited to the examples shown and in particular more than two thicknesses of covers per side of cable tray can be used.

Claims (11)

Fire protection blanket (1) characterized in that it comprises a first layer (10) consisting of a fabric of a heat-resistant material, in particular a glass fabric or a fabric with meta-aramid fibers and a second layer (11) consisting of an intumescent material such as a silicone or other acrylic, epoxy or PVC intumescent material, said intumescent material containing graphite and/or silicate fillers. Fire protection cover according to Claim 1, in which a third layer of an adhesion material (12) is interposed between the first layer and the second layer. Fire protection cover according to Claim 2, for which the bonding material (12) is of the same chemical nature as the intumescent material and of the polycondensation or polyaddition type suitable for promoting the adhesion of the intumescent material to the first layer. Fire protection cover according to claim 1, 2 or 3 for which the first layer is coated on its side opposite the second layer with a finishing silicone layer (13) forming an outer face of the cover which forms on the fabric a layer of airtightness or watertightness which can be decontaminated by washing. Fire protection cover according to Claim 4, in which the said finishing silicone layer (13) is of the polycondensation or polyaddition type. Fire protection blanket according to any one of the preceding claims, for which the intumescent material (11) is of the polycondensation or polyaddition type and provides fire protection by modifying its thermal properties during its expansion. Device for protecting one or more elongated elements (2) comprising one or more covers (1a, 1b) according to any one of the preceding claims being positioned on said elongated elements. Device for protecting one or more elongated elements (2) according to claim 7 comprising a plurality of said juxtaposed covers (1a, 1b) on said elongated elements. Device for protecting one or more elongated elements (2) according to claim 7 comprising a plurality of said covers arranged in superimposed (1a, 1'a, 1b, 1'b) or alternate (1a, 1b, 1c, 1d) multilayers on said elongated elements. Device for protecting one or more elongated elements (2) according to claim 7 comprising a plurality of cover plates deposited in staggered rows and comprising:
- a first layer of cover plates (3a and 3b) placed on at least one face of the cable tray, leaving first spaces (6) between them;
- a second layer of cover plates (4a, 4b) placed on the first layer, overlapping the first spaces and themselves leaving second spaces (7) between them;
- a third layer of cover plates (3'a, 3'b) overlapping the second spaces (7) and separated from each other by third spaces (8) and;
- at least a fourth layer of cover plates (4'a, 4'b) overlapping the third spaces (8) and separated from each other by fourth spaces (9);
said spaces being of such a length that the ends of the plates of said layers are stacked on top of each other. Device for protecting one or more elongated elements (2) according to any one of Claims 7 to 10 for which the said elongated elements are cable trays or pipes, the covers being arranged on one or more faces of the cable trays or pipes and held by clamping means such as clamps, wire or other.