EP0635617B1 - Transparent flame shielding panel - Google Patents

Abstract

The invention relates to a transparent so-called flame-shielding (fire-stop) panel capable of retarding the propagation of flames and/or fumes or gas during a fire and including a glazed element comprising tempered (quenched) silicate-soda-lime glass equipped with means capable of fastening it to a supporting structure of a building. It is designed so as to be able to deform freely when it is heated up by fire, leaving peripheral clearances measured when cold between the glazed element and the fastening means and/or between fastening means and supporting structure which are sufficient to permit its expansion. <IMAGE>

Description

The invention relates to a transparent flame-retardant panel intended, when installed in the facade of a building, to delay the spread of a fire from one floor to another or, when installed in a partition, to avoid flame spread between neighboring rooms. This type of flame retardant panel can also be used as a gas separator intended to equip the upper part of premises, an element also designated commonly known as the block screen.

Such a screen makes it possible to limit the propagation, even inside a room, flames, fumes and toxic gases that are released when a fire Declares itself. It is particularly useful for large premises, especially intended to receive the public, it is usually fixed to the ceiling, according to a substantially vertical plane.

Fire-resistant glazing, called flame arrester (PF) according to the ministerial decree French from 04.21.1983 and corresponding to classes G 30 or G 60 of the standard German DIN 4102 have the property, during a fire (standard), to stay in place and prevent the passage of smoke and hot gases. The tests standards of this type of product are described among others in ISO standards 834 and ISO 3009.

It is known to use laminated glazing formed by the assembly several sheets of thermally toughened soda-lime-silica glass, the association being carried out with polyvinyl butyral (PVB) films, for constitute glazed flame arresting systems. So the European patent EP - 219 801 B1 proposes to combine for this purpose at least three sheets of glass float with a thickness of at least 3 mm using PVB to make a glazing G 30. We also know specific mounting techniques that   allow a sheet of tempered glass based on a silica-soda-lime composition classic to have a flame retardant behavior of more than half an hour. Thus, the assembly of French patents FR - 2 282 033, FR - 2 314 993 and FR - 2 366 434 makes it possible to expose the edges to heat radiation while that of European patent EP - 0 079 257 B allows indirect heating of the same edges of the glazing. However, the techniques of the prior art are limited relatively small dimensions. In particular, when you need a regular heating of the edges, it is essential that the flames which heat the glass to be uniform over its entire surface, which is all the more difficult to carry out during standardized tests or all the more random in the event real fire, that the glazing surfaces are larger. Likewise, in the case of triple laminated glazing of EP - 0 219 801. if the dimensions increase, the deformations of the frame due to the thermal stresses which it undergoes become very important and risk breaking the glass or, at least, causing loss sealing around its periphery.

It is known in particular thanks to the European patent application EP -A- 0 569 298 to equip an insulating fire-resistant glazing with a device which ensures normally waterproof but which, during a fire, limits the overpressure to inside the glazing and thus prevents its explosion.

Document US-A-4,081,931 describes an attached smoke-resistant wall which features a contoured bar with an open downward slit which is updated in the ceiling of a building. Bolts screwed to this so-called bar slot profiled support a bearing support and a plate attached to this so-called slot profiled bar by means of said bearing support.

It is also known from document US-A-4 601 143 a flame-retardant wall comprising a transparent panel which is supported by a frame for protect the peripheral edge of this panel from delamination. In addition, support means support the frame in a wall so as to compensate expansion of the panel and frame to prevent sagging of the panel due to the resulting delamination of the panel and premature failure.

The invention sets itself the task of producing very large glazing dimension that is flame retardant for durations significantly greater than the   half hour and which can be used either in a dividing wall or in a facade either as a cantonment screen.

The technique described in patent EP - 0 219 801 - B1 allows, in the case of dimensions 160 x 120 cm ² , to reach a flame arrester duration of 36 minutes and this thanks to the combination of a triple laminated glass of which at least the outer sheets are quenched in a conventional manner and of a particular assembly which clamps the periphery of the glazing by means of windscreens screwed onto a metal support frame so as to prevent any movement of the glazing relative to the wall which supports it. When such glazing is tested under the conditions of the standard, that is to say by subjecting one of its faces to a temperature rise Δ T as a function of time t of the type:
ΔT = 345 Log ₁₀ (8t + 1); (ΔT in kelvins and t in minutes) the mounting conditions systematically lead to any thermal gradient being transformed into stresses in the glass plate. These can reach significant values, and if they are extension constraints, they compensate for the compression preload of the toughened glass, any overshoot leading to a risk of breakage. On the other hand, the assembly according to the invention allows a relaxation of the stresses of thermal origin since the glass can deform freely: the breaking limit of the tempered glass, much higher thanks to special conditions, is only reached for markedly higher thermal gradients. However, the deformations of the flame-resistant glazing according to the invention, thanks to the sealing technique and the possibility of expansion, remain compatible with a behavior of barrier to hot gases, fumes and flames.

In comparison with the flame-retardant glazing system which uses a laminated-tempered mounted in a more traditional way and whose effect is to limit the thermal gradient on the rear glass, the glazing of the invention also allows a significant improvement, since by allowing the deformation of the glass corresponding to a given thermal gradient, it limits the constraints which for the glazing and here also delays the breakage of this rear glass. Sealing, too, is better ensured by the techniques of the invention.  

The techniques usually used to make panels flame retardant transparencies use either borosilicate glasses possibly tempered, or, as we saw above, with soda-lime-silica glasses one or more of which has undergone traditional thermal quenching.

The disadvantage of borosilicate panels is their high price and, often the very poor optical quality of the plate. Furthermore, these products are only available in reduced dimensions.

We have seen that traditional tempered glasses, even when combined in laminated sets as in document EP - A - 0 219 801 are also of limited dimensions.

The invention addresses both the problem of mounting the glazed element and that of his nature.  

For mounting, the invention provides a transparent flame-retardant panel able to delay the spread of flames and / or smoke or gas in the event according to claim 1.

The hardened plate (s) preferably have a thickness greater than 5 mm, in addition, their edges are polished with a roughness of the polish less than 5 µm and their quenching stress is greater than 120 megapascals and preferably of the order of 140 megapascals. The panel of the invention can be advantageously used as glazing in a facade or in a partition. So he is, usually fixed to the supporting structure so that the means of fixing to the frame of the glazing bead type enclose the four sides of the glazed element. If, on the other hand, it is used as a blocking screen in the upper part of premises, its fixing means must be adapted, with in particular a frame or a glazing bead enclosing only its upper edge, once fixed to the ceiling or false ceiling.

The glazed element of the invention exists in several variants, either it is a single glazing with a thickness of the order of 6 mm or it is a laminated glass comprising at least two sheets of tempered glass each of a thickness greater than or equal to 6 mm, the plates preferably being two in number. Advantageously, the laminated glazing comprises a single interlayer film of polyvinyl butyral with a thickness less than 1 mm. But the glazed element according to   the invention can also be an insulating glazing including at least the glass plate on the side opposite the fire is a tempered glass conforming to the criteria defined above, as for the plates exposed to fire, they can be made of tempered glass normal or laminated glass.

Preferably, the insulating glazing comprises a balancing element which limits overpressure when the glazing is exposed to fire and the glass plates are assembled at their periphery with a silicone-based glue.

The combination of a special hardening treatment and mounting special provision in the main claim avoids that the constraints mechanical introduced both by thermal gradients and by deformations mechanical elements do not exceed the breaking limit of tempered glass. This therefore remains intact throughout the temperature range where its deformation is elastic. When it reaches the plastic deformation range, it is no longer susceptible to undergo the fragile breakage typical of glass materials.

Preferably, if it is intended to use the panel as an element of separation of the block screen type, the glazed element of the panel can have glazing called fireproof and formed of at least two glass plates parallel to each other and define an intermediate space in which is placed a layer made of an aqueous gel whose aqueous phase contains a salt, a type of glazing, for example known from the patents FR - 2 346 548, EP- 0 214 056 or EP- 0 442 768 as well as patents FR - 2 027 646 or FR - 2 321 575. Their operating principle is as follows: the heat, in case of fire, begins to be absorbed into the glazing by water from the aqueous gel and it vaporizes it. In a second phase, after evaporation of the water and combustion of the phase solid organic gel, said gel constitutes a solid crust which makes a “Shield” which insulates against thermal radiation and which, in the context of the invention can also act as a barrier to flames or gas.

The glazed element can also, in addition to the plate or plates of soda-lime-silica glass , include plates in so-called special glasses presenting by their composition increased resistance to heat, especially one or more borosilicate glass plates. We can also mention the plates in reinforced silico-soldo-calcic glass.  

The glass element mounting system, always when it is used of separation element of the blocking screen type, i.e. the assembly means that will allow it to be fixed to the supporting structure, intervenes also significantly in the general appearance of the element of separation. Preferably, these means are therefore designed so as to leave visible at least one of the sides of the glazed element, in particular its edges lateral and most of its lower edge. (In the context of the invention, the terms "lateral", "upper" or "lower" are understand with reference to the separation element that we consider once fixed to the supporting structure, like a ceiling, according to a plan substantially vertical).

Thus leaving at least one free side, and preferably three, brings in effect a double advantage: first of all, such an assembly greatly strengthens the character of discretion and the impression of lightness already given by all of the separating element thanks to the glass material used. By the way, these edges exposed will allow the glazed element to expand and deform freely in these areas once subjected to heat, which reduces the risk of breakage all the more abrupt of it and consequently increases its resistance to fire.

These fixing means include in particular support means of a part of the lower edge of the glazed element, means in particular located at the corners of said edge and which may take the form of small support lugs.

In this way, we keep all the lightness previously mentioned, while optimally guaranteeing the durable and secure mechanical fixing of the glazed element to the supporting structure.

The fixing means may also include means for holding at least one of the edges of the glazed element, in particular its upper edge. It is understood as a means of maintenance, in the context of the invention, any means for positioning the glazed element relative to the supporting structure and / or to keep it fixed more or less strongly and / or to ensure gas tightness between the separating element and the structure or ceiling against which it is subsequently disposed. These means of maintenance include in particular a frame or a glazing bead not covering   preferably at most 15 millimeters from the periphery of the edge, distance measured at from his song. This ensures gas tightness between said edge and the frame or the glazing bead. This distance of at most 15 millimeters is indeed advantageous in the sense that the portion of glass which is enclosed in the frame where the glazing bead is sufficiently reduced to reduce the thermal gradients in the glazed element subjected to fire between its middle part and its peripheral edges covered by said frame, thermal gradients which are the source of sudden glass breakage. However, this distance remains sufficient to ensure satisfactory maintenance of the glazed element in its frame. The sealing mentioned is of course important to avoid the circulation of flames and smoke between frame and glass.

Advantageously, provision is made for maintaining the glazed element in its frame, especially at its upper edge, be secured using of a fibrous material interposed between the two, a fibrous material which may be of metallic or ceramic nature. The advantage of a fibrous material is its ability to compression, which makes it possible to "adjust" the intensity of the element's tightening glazed in its frame by mechanical means of the screw and bolt type, and therefore to adjust the fixation between them. If it is metallic in nature, which is for example known from patent application EP-0 568 458, it contributes on the one hand, by its high thermal conductivity, to decrease the thermal gradients between the edge of the glazed element covered by the frame and the rest of said element. On the other hand to slow down the fall of the glazed element by sagging when it softens under the effect of heat, the metal fibers becoming embedded in the softened glass and the holding back as well. The type of mounting recommended in this request allows a Very effective "pinching" of the edge of the glazed element in its frame.

Furthermore, these means for holding the upper edge of the glazed element can be designed so that once the assembly is attached to the structure load-bearing, they guarantee gas tightness between the element of separation and said supporting structure of the ceiling type. So the way of holding advantageously in the form of a frame can be extended so that it can be place on the ceiling without discontinuity of contact between frame and ceiling. For ensure continuity between frame and ceiling-type supporting structure, without prevent the expansion of the frame in the event of fire heating,   can have any suitable type of fibrous or compressible joint between them. It goes from so that, according to the design of the room to be equipped, the fixing of the element separation can be done directly to an upper supporting structure, type slab, while said element is in fact pressed against a false ceiling which is itself fixed to the slab. Can also be provided with a sealing means additional sealant type suitable between frame and ceiling (or false ceiling).

Connection means can also be advantageously provided for connecting the support means, of the lug type, to the lower edge of the element glazed to the frame type holding means of the upper edge of the latter. Of preferably, these connecting means, in the form of rods, run along without contact at at least one of the side edges of the glazed element and are designed so as to being able to pivot relative to said holding element.

In this way, it is easy to quickly secure the glazed element to its different fixing means.

The means for fixing the glazed element are preferably metallic, the metal exhibiting good fire resistance and also thermally expanding more than the glass element. In this way, particularly in terms of the means of maintaining the frame type of the upper edge of the glazed element, said frame will expand at least as much as glass during a fire and therefore will allow it to relatively freely deform under heat, even if the glass initially is relatively firmly held in the frame.

Depending on the dimensions of the room to be equipped with the elements of separation according to the invention it may be necessary to provide a plurality of elements arranged side by side. It is therefore advantageous to assemble them using gas-tight sealing means to avoid traffic flames and smoke between two adjacent separating elements.

It should also be noted that with the assembly according to the invention, it is possible to manufacture efficient dividers, large and offering however great job security. Thus, the glazed elements according to the invention can usually have a height of 0.3 to 1 meter, a length from 1 to 2.5 meters and a thickness of about 6 to 10 millimeters or more.

• figure 1 : une coupe d'un cadre d'un vitrage monolithique conforme à l'invention et,
• figure 2 : un vitrage double.
• figure 3 : un écran de cantonnement selon l'invention,
• figure 4 : une vue partielle de la fixation en partie haute de l'élément vitré de l'écran de cantonnement selon la figure 3,
• figure 5 : une vue partielle du montage de la fixation en partie basse de l'élément vitré de l'écran de cantonnement selon la figure 3.

The details and advantageous characteristics of the invention appear from the following non-limiting embodiments and illustrated with the aid of the figures which represent: (the first two figures relate to a panel used as glazing. The following figures relate to a panel used as a block screen).

• FIG. 1: a section through a frame of a monolithic glazing according to the invention and,
• Figure 2: double glazing.
• FIG. 3: a blocking screen according to the invention,
• FIG. 4: a partial view of the fixing in the upper part of the glazed element of the blocking screen according to FIG. 3,
• FIG. 5: a partial view of the mounting of the fixing at the bottom of the glazed element of the blocking screen according to FIG. 3.

In Figure 1 there is shown in 1 a monolithic toughened glazing according to the invention. It is a silico-soda-lime float glass which has undergone a particular treatment which will be presented in detail later. The sheet steel profile folded 2 with a thickness of about 2 mm constitutes the frame of the glazing, it is linked to the structure of the building under the conditions described below. This profile 2 has an angled section rebate which carries the glass through lower support wedges 5 made of an asbestos-based material. The PROMABEST Y name of the PROMAT Company in 78540 Vernouillet (France) indicates a suitable material. In the case of a 10 mm glass 1 170 cm thick and high, the dimensions of the support wedges 5 are: width 13 mm, thickness 8 mm, they extend continuously under the entire horizontal dimension of the glazing. On both vertical sides and above the glazing a space of equivalent thickness is left free. On either side of glass, seals 6 in ceramic fiber hold it laterally. For the sealing of the joint covers 7, for example made of silicone, complete the assembly. The lateral holding is ensured by a glazing bead 3 also folded sheet. She has a longitudinal lug 10 which fits into the housing 9 of the profile main. From place to place, a self-tapping screw 11 prevents during the fire at the exit of the glazing bead, the space between the screws 11 is around 70 cm or less. The height of the profiles 2 is, for glazing with a dimension of 1.70 m squared, around 80 mm. The width must be narrower, of the order of half.  

Profile 2 is not in direct contact with the building structure but it exists all around the frame, when cold, a significant peripheral clearance (at least 0.6% that is to say, for example, 20 mm of cumulative play with respect to the structure for overall dimensions of the glass assembly of the order of 3 m).

In the figure, this game shown in 17 is filled with rock wool.

The lateral fixing of the frame perpendicular to the glass, on the other hand, is rigid.

A means of achieving these two conditions, lateral fixing and possibility of longitudinal expansion, is achieved by the system shown at the bottom of Figure 1. L-shaped profiles on all four sides of the frame are rigidly attached to the structure by means (lag screws for example) not shown. In the parallel plane in the glazing, the fixing is done by screws 13 fitted with washers 18, they pass through oblong holes 12 (the screws are at the end of these holes directed towards inside the frame). These holes have a length at least equal to the clearance provided in 17. In the figure, the assembly is provided so that the light comes from the right, in this case, it is advantageous that the washers 18 (on the side of the light) are made of a material which flows with heat but whose cold modulus remains high and low creep; An aluminum alloy is suitable as a material for these washers; but even with steel washers, in general, the efforts of expansion and the clearance provided by the heating of the screw are such that the expansion of the frame is not prevented.

On the other side, a fixing of the same type allows a plate 14 to close off the passage without hindering the expansion of the frame by means of screws 15 passing through oblong holes 16.

The space 17 is, as we have seen, advantageously filled with rock wool.

The clearances which are provided, on the one hand at the periphery of the glass in 5 and on the other part at the periphery of the frame at 17 make it possible to greatly limit the stresses on the glass during a fire. If the game around the glass can remain the same, regardless of the dimensions of it, it is not the same of the set 17, at the periphery of the frame. It must be all the more important as the dimensions of the frame are themselves more important. In general, a set of 8 mm at the periphery of the glass is sufficient. On the other hand, as we have seen, the game 17 must be about 0.6% of the corresponding size of the rack.  

An equally important parameter is the overlap height of the rebate on one side and the glazing bead on the other on the glass 1. This height which corresponds to the “shadow cast” by the steel of the frame on the glazing during the fire must remain below 15 mm, the value of 10 mm is suitable perfectly.

The soda-lime-silica glass 1 in FIG. 1 has a thickness of 6 mm. He has underwent special treatment. In general, the glazed element consists glazing designed to stay in place during a fire. The combination triple described in European patent EP - 0 219 801 B1, with dimensions height 160 cm, width 120 cm and combinations of thickness 4 mm tempered, 4 mm annealed, 4 mm hardened, for example meets this requirement during a duration of 36 minutes when subjected to the temperature rise curve standardized.

But the glass elements of the invention both simpler in design and more rigorous allow to obtain fire resistance of longer duration. They have one or more plates of soda-lime-silica glass, one of which least underwent special treatment. This consists on the one hand of a polishing edges with a polish roughness of less than 5 µm and on the other hand thermal quenching treatment providing compression stress at least 120 megapascals and preferably 140 megapascals.

The assembly shown in Figure 1 is compatible as we have seen with element monolithic 6 mm thick but, provided that the width of the profile 2, it is also compatible with thicknesses of 8 or 10 mm (monolithic elements having undergone the same processing steps).

Another combination was also tried and gave satisfaction, it it is the association of two monolithic glasses of the previous type associated in laminated glazing thanks to a polyvinyl butyral (PVB) film. Thicknesses of glass of twice 8 mm and twice 10 mm were satisfactory, the glasses were associated by a single sheet of PVB with a thickness of 0.76 mm.

Figure 2 shows the association of a frame little different from that of Figure 1 with a glazed element consisting of insulating glazing.  

The insulating glass 20 consists of two glasses 21, 22 of which at least one 22 has undergone the treatment of the invention, it is it which is located on the side opposite the fire.

It is necessary that the two glasses 21, 22 have undergone the same treatment in case the flame arrester wall must be able to work in both directions.

The profile 23 which separates the two glasses is made of steel, the assembly is made with a silicone sealant 24. In addition, the insulating glass is equipped with a device not shown which allows pressure balancing between the interior and exterior of the glazing when a fire causes its warming up. The device described in the European patent application of filing number 93 401 162.8 corresponding to FR-2,690,946 and which consists of a special corner with a fusible cover used to assemble the profiles 23 fits perfectly.

The mounting of the insulating glazing 20 in the profile 25 is identical to that of the figure 1, the connection method between the frame and the building structure is also the same.

In the case where the two glasses 21, 22 are not identical, we can associate with the glazing 22 which has undergone the special preparation in accordance with the invention, a glazing 21 which is either a normal tempered glass or a laminated glass combining two annealed silico-soda-lime glasses.

Two fire tests according to ISO 834 and ISO 3009 were carried out. In both cases, the frame was of the type of those in Figures 1 and 2. The elements panes were on the one hand made of 6 mm thick monolithic glass and on the other hand laminated glazing consisting of two 10 mm glasses assembled with PVB.

TEST # 1

hauteur 109 cm, largeur 105 cm

et hauteur 109 cm, largeur 172 cm

pour les verres du bas et :

hauteur 168 cm, largeur 105 cm

et hauteur 168 cm, largeur 172 cm

pour ceux du haut. The 3m x 3m oven rack was equipped with 4 glazed elements whose dimensions were respectively:

height 109 cm, width 105 cm

and height 109 cm, width 172 cm

for the bottom glasses and:

height 168 cm, width 105 cm

and height 168 cm, width 172 cm

for those at the top.

All had undergone special shaping and tempering.   Their common thickness was 6 mm.

• à la 12^ème minute, le montant vertical central se cintrait vers le four avec une flèche de 10 cm,
• à la 24^ème minute, montant et traverse centraux avaient une flèche de 15 cm et à 38 minutes, de 20 cm,
• à la minute 43, la flèche atteint 25 cm, la déformation du vitrage le plus grand est visible,
• à la 59^ème minute, le plus grand des verres du haut commence à fluer et libère pour la première fois le passage aux flammes et aux gaz : fin de l'essai.

The temperature rise in ° C followed the law: TT o = 345 Log 10 (8 t + 1) where time t is expressed in minutes.

• at the 12 ^th minute, the central vertical upright bent towards the oven with a 10 cm arrow,
• at the 24 ^th minute, the central upright and cross had a 15 cm arrow and at 38 minutes, 20 cm,
• at minute 43, the arrow reaches 25 cm, the deformation of the largest glazing is visible,
• in the 59 ^th minute, the largest glasses from the top starts to flow and releases first passing flame and gas: end of the test.

TEST # 2

The glazed element is a 2 x 10 mm laminated glazing, each element component in soda-lime-silica glass has undergone two special treatments described above. They are associated with a single thick PVB sheet 0.76 mm. The glazing is vertical, with a height of 2.78 m by a width of 1.68 m.

• dès la 3^ème minute le vitrage se déforme (convexité du côté du four),
• à la minute 7 le verre côté chaud se fragmente en tout petits morceaux qui restent collés à l'autre verre,
• minute 14, inflammation du PVB. Quelques fragments du verre côté chaud tombent,
• 18^ème minute, le PVB noircit,
• minute 21 : la déformation (cintrage) du vitrage atteint 5 cm,
• minute 36 début de fluage du vitrage mais il reste maintenu en partie haute,
• 42^ème minute, la partie haute du vitrage sort de la pareclose,
• minute 43 : fin de l'essai, le vitrage s'effondre et libère le passage pour les flammes et les gaz.

The test takes place under the usual conditions:

• from the 3 ^rd minute the glazing deforms (convexity on the side of the oven),
• at minute 7 the glass on the hot side breaks up into very small pieces which remain stuck to the other glass,
• minute 14, inflammation of PVB. Some fragments of the glass on the hot side fall,
• 18 minutes, ^the PVB blackens,
• minute 21: the deformation (bending) of the glazing reaches 5 cm,
• minute 36 start of creep of the glazing but it remains maintained at the top,
• 42 ^th minute, the upper part of the glazing comes out of the glazing bead,
• minute 43: end of the test, the glazing collapsed and freed the passage for flames and gases.

A second embodiment of the invention is shown in Figures 3 to 5. This is a cantonment screen, or separation element.  

The separating element 31 shown schematically in Figure 3 is intended to be suspended in a substantially vertical plane from the ceiling (not shown) of a large room in order to block, or at least stop the spread of smoke, flames and gases for a certain period of time toxic throughout the premises if a fire breaks out there.

This element 31 mainly comprises a transparent glazed element composed of a so-called flame arrester glazing with good fire resistance. It's about monolithic glazing (it could of course also have a structure laminated or insulating glass) in float glass soda-lime silica having undergone on the one hand, a polishing of its edges in order to obtain a lower polished roughness at 5 micrometers and on the other hand thermal quenching in order to give it a surface compression stress of at least 120 Mpa and here around 140 Mpa, just like the monolithic glazing in Figure 1 above.

Its dimensions are approximately as follows: a thickness of 6 millimeters, a width of 50 centimeters and a length of 1.8 meters.

In the upper part of the glazing 32, the edge of the glazing 32, so that which is going to find the closest to the ceiling, with its periphery enclosed in a profile metal 35 which, as shown in Figure 4, consists of a plate 36 and a angle iron 37. The angle iron 37 is screwed onto the flat 36 using associated nuts 38 screws 39. There is provision to interpose between glazing 32 and profile 35 a material fibrous 40, or ceramic fibers sold in particular under the name of Fiberfrax, either in metallic fibers, in particular in the form of a covered braid in accordance with the aforementioned patent application EP-0 568 458. If he is chosen metallic, it allows, by penetrating the surface of the softened glass, to slow down its fall from the heat of a fire and because he is a good conductor thermal, it limits the thermal gradient between the edge of the glazing 32 in the frame profile 35 and the rest of the glazing.

This fibrous material, whatever its nature, exhibits at rest a section of approximately 10 x 5 square millimeters.

By adjusting the tightening of the bolt 38, 39, the fibrous material 40 is found more or less strongly compressed and the glazing 32 more or less firmly held in profile 35.  

Since the profile 35 is here of a metallic nature, it is however not necessary to provide at the start too much cold play, between frame and glazing allowing the glazing to deform in the event of fire, since the profile will tend to expand more than glass, thereby creating the necessary clearance for time of fire. If the profile is of a different nature, it may be advantageous however, to provide a greater peripheral clearance, when cold, between the glazing 32 and profile 35 to prevent the glazing from suddenly breaking during a fire and is therefore rendered completely ineffective.

A joint cover 41 made of a gas-tight and heat-resistant material, for example that marketed under the name of Pyrosil B, is deposited on the fibrous material 40 to ensure a neat finish. In conjunction with the fibrous material 40, it also effectively blocks the passage of flames and smoke between the upper edge of the glazing 32 and the profile 35.

The dish 36 is provided in the upper part with orifices 42 regularly distributed over its entire length and intended to be able to fix it securely to the ceiling using known mechanical means not shown. The separating element 31 can therefore, by extending this dish 36, press against the ceiling, in prohibiting any passage of gas or flames between the two.

Care is taken that the periphery of the upper edge of the glazing 32 measured at from its edge is only covered by about 10 millimeters by profile 35, so as to ensure sufficient maintenance of the glazing 32 in its profile 35 while by limiting as much as possible the importance of the thermal gradients which can be established during a fire between the edge of the glazing covered by the profile and the rest of the glazing which is directly exposed to heat, gradients which are the source of quick glass breakage as already mentioned.

The glazing support effort 32 can be partly and even essentially ensured by a firm hold of the upper edge of the latter in its profile 35.

It may however be preferable, for greater safety, to provide support for the glazing 32 in the lower part, which is the object of Figure 5. This support consists to support the two lower corners of the glazing of the glazing 32 using lugs 33 taking the form of metal sections of U-shaped section. They can be provided with a length adapted so that they provide effective support while remaining sufficiently discreet. A good compromise is for example a length of   in the range of 15 to 25 millimeters. These lugs 33 are themselves supported by metal rods 34 of square cross section of approximately 12 x 12 square millimeters which run along the side edges of the glazing 32 without touching them and are fixed to the profile 35 so as to allow a pivoting movement of the rods by report to the profiflé.

The mounting of the glazing therefore minimizes the risk of breakage of the glazing, limiting the thermal gradients in the glazing and leaving it possibility of deformation, while providing it with effective mechanical support times the separating element 31 suspended.

The fact that the side edges and almost the entire bottom edge are left free makes the whole discreet and aesthetic, and the very characteristics glazing ensure excellent fire resistance.

In order to assess how long such a separating element or cantonment screen 31 can perform its flame barrier function and gas, it was subjected to fire tests according to ISO 834 and ISO 3009 standards under the same conditions as above.

The separating element 31 is during the test located at 190 millimeters parallel and behind the glass ceramic glass constituting the front face of the oven used to simulate the fire.

During the first twenty minutes of the test, the screen 31 retains its mechanical strength without any weakness. From the 25 ^th minute, the glass begins to sag and become thinner below the fixing region by clamping in the profile 35. The collapse thereof occurs to the ^35th minute.

The separation elements according to the invention are therefore capable of blocking in the upper part of premises the propagation of flames and gases for at least about 30 minutes. They therefore have the required level of fire resistance while being very aesthetic.

If you want an extremely effective tightening of the upper edge of the glazing in its frame, the assembly described in the aforementioned request EP - 0 568 458 is also particularly recommended. So both by the choice of the fire-resistant glazed element itself and by the choice of its mounting, the screen according to the invention can be adapted according to the needs and the level of performance required. In any event, the type of mounting allows the element   glazed to expand freely, since it has three of its free sides, its side upper clamped with a fibrous material in a manner allowing also some dilation.

In addition, the screens can be placed side by side if necessary, assembling for example using a heat resistant and waterproof seal gas, disposed between the rods 34 of the screens that are assembled. Can also consider providing each screen 31 with a single rod 34 along only one side edges of the glazing but provided with two lugs 33 able therefore to support simultaneously the two contiguous corners of two dividing elements assembled side by side.

The panes just described and their mounting technique allow thus, from inexpensive and excellent optical quality lenses, obtaining high performance flame retardants.

Before the development of glass products and mounting techniques of the invention, only small products or special glasses (armed glasses, borosilicates) provided flame retardant glazing. In particular, the mounting techniques according to the invention make it possible to achieve the intrinsic limits of the glass product itself whereas previously its cassese was producing long before the intrinsic limits of the glazed element are reached.

Claims (19)

1. Transparent, fire-retarding panel (31) able to retard the propagation (2, 3, 25, 33, 34, 35) of flames and/or fumes or gases in the case of a fire and incorporating a glazed element (1, 21, 22, 32) having one or more soda-lime-silica glass plates, whereof at least one has undergone a thermal tempering treatment and equipped with means able to fix it to a load-bearing structure of a building, the glazed element being able to freely deform during its heating during a fire, the total of the peripheral clearances measured cold between the glazed element and its means for fixing to the load-bearing structure and between said means and said structure being sufficiently large to permit the free expansion of the glazed element caused by its heating, characterized in that the fixing means (2, 3, 25, 33, 34, 35) equipping the glazed element (1, 21, 22, 32) on at least one of its sides only cover the periphery of the glass plate (1, 22, 32) having undergone thermal tempering by a distance from its edge equal to a maximum of 15 mm and preferably 10 mm.
2. Panel according to claim 1, characterized in that the glass plate or plates of the glazed element having undergone thermal tempering have a thickness greater than 5 mm, in that their edges are polished with a roughness of the finish lower than 5 µm and that their tempering stress exceeds 120 megapascals and is preferably approximately 140 megapascals.
3. Panel (31) according to claim 2, characterized in that the glazed element (1, 21, 22, 32) has a single glass plate with a thickness of approximately 6 mm.
4. Panel (31) according to claim 2, characterized in that the glazed element (1, 21, 22, 32) is a laminated glass, having inter alia at least two tempered glass plates, each with a thickness greater than or equal to 6 mm.
5. Panel (31) according to claim 4, characterized in that the laminated glazing has a single, intercalated polyvinyl butyral film with a thickness below 1 mm.
6. Panel (31) according to claim 2, characterized in that the glazed element (1, 21, 22, 32) is a insulating glazing (20), whereof at least the glass plate (22) on the side opposite to the fire is of a tempered glass according to claim 2.
7. Panel (31) according to claim 6, characterized in that the plate or plates (21) exposed to the fire are of normal tempered glass or laminated glass.
8. Panel (31) according to claim 6 or 7, characterized in that the insulating glazing (20) has a balancing element limiting the overpressure when the glazing is exposed to the fire.
9. Panel (31) according to one of the claims 6 to 8, characterized in that the glass plates are assembled at their periphery with a silicone-based adhesive (24).
10. Panel (31) according to one of the preceding claims, characterized in that the maintaining of the glazed element (1, 21, 22, 32) in the fixing means (2, 3, 25, 33, 34, 35) having the form of a frame or bead (35) is ensured with the aid of a fibrous material (40) interposed between the two, in particular having a ceramic or metallic nature.
11. Panel (31) according to one of the preceding claims, characterized in that it is intended to be placed in the upper part of rooms as a separating element, the means (33, 34, 35) for fixing the glazed element to the load-bearing structure of the ceiling type being designed in such a way as to leave visible at least one of the sides of said glazed element (32), particularly the lateral borders and most of the lower border of the glazed element (32) once fixed to the load-bearing structure according to a substantially vertical plane.
12. Panel (31) according to claim 11, characterized in that the means (33, 34, 35) for fixing the element (32) to the load-bearing structure incorporate support means (33) for part of the lower border of the glazed element (32) once fixed to the load-bearing structure, notably at the corners of said border.
13. Panel (31) according to claim 11 or 12, characterized in that the means 933, 34, 35) for fixing the element (32) to the load-bearing structure incorporate means (35) for maintaining at least one of the borders of the glazed element (32), particularly solely the upper border of said element (32) once fixed to the load-bearing structure, said maintaining means comprising a frame or a bead preferably only covering at the most 15 millimetres of the periphery of the border measured from its edge and ensuring sealing with respect to the gases between the border and the frame or bead.
14. Panel (31) according to one of the claims 11 to 13, characterized in that the means (35) for maintaining the upper border of the glazed element (32) are designed in such a way that when the separating element (31) is fixed to the load-bearing structure of the ceiling type, they guarantee the seal with respect to the gases between the separating element (31) and the load-bearing structure of the ceiling type or the false ceiling.
15. Panel according to one of the claims 11 to 14, characterized in that the support means (33) are connected to the maintaining means (35) by connecting means (34), particularly rods passing without contact along at least one of the lateral borders of the glazed element (32) once the assembly has been fixed to the load-bearing structure and able to pivot with respect to said maintaining means (35).
16. Panel (31) according to one of the claims 11 to 15, characterized in that the means (33, 34, 35) for fixing the glazed element (32) are metallic.
17. Panel (31) according to one of the claims 11 to 16, characterized in that the glazed element (32) is a fire-retarding glazing formed from at least two parallel glass plates and defining an intermediate space in which is placed a layer formed from an aqueous gel, whose aqueous phase incorporates a salt.
18. Panel (31) according to one of the claims 11 to 17, characterized in that the glazed element (32) also incorporates at least one borosilicate glass plate or at least one reinforced soda-lime-silica glass plate.
19. Plurality of panels (31) according to one of the claims 11 to 18, characterized in that they are assembled in juxtaposed manner with the aid of gas-tight, grouting means.