DE3510935A1 - Fire-resistant wall element which reduces the passage of heat and is intended in particular as an insert for a fire-retardant door, process for the production thereof and fire-retardant door equipped therewith - Google Patents

Abstract

A fire-resistant wall element, for instance as an insert for fire-retardant doors, for example as composite panel, is obtained by combining at least one mineral-fibre insulating layer (16) with at least one fire-protection zone (17) consisting of granular, bound, carbonate-containing rock such as dolomite or limestone. Possible inorganic binders are, in particular, a non-alkaline hydraulic binder such as magnesium oxychloride or magnesium oxysulphate, or a thermoplastic binder such as an aqueous melt of aluminium sulphate. In the event of fire, a plurality of highly endothermic reactions take place at high temperature, giving, on balance, a very high negative heat of reaction. Remaining after the corresponding conversions and reactions are predominantly fireproof oxides, such as magnesia or quicklime; carbon dioxide is the only gas to escape. Even with a low overall thickness, a wall element of this type satisfies the requirements for fire-resistance grading F90 in accordance with DIN 4102, Part 5. <IMAGE>

Description

Fire-resistant, reducing the heat transfer

Wall element, especially as an insert for a fire-retardant door, as well as process for its manufacture and fire-retardant door equipped therewith The invention relates to a fire-resistant, heat transmission reducing Wall element, in particular as an insert for fire-retardant doors, according to the preamble of claim 1, as well as a particularly suitable method for its production according to the preamble of claim 14 and a fire-retardant equipped therewith Door according to the preamble of claim 15.

To achieve a high fire resistance class for wall-like construction elements attempts have been made for a long time to combine thermal insulation layers with fire protection zones, their Heat absorption capacity is significantly increased in that when the temperature rises endothermic chemical reactions or phase changes occur in the event of fire. As is well known, fire resistance is determined by how long one has predetermined temperature rise one side of the wall element the other side of the wall element below a certain limit temperature, for example 1800 C, remains. The service life of the wall element until this limit temperature is reached on the cold side in minutes results in the fire resistance class, whereby according to DIN 4102, Part 5, the classification in, for example, the fire resistance class F30 30-minute downtime means, F90 a 90-minute dwell time, and so on. It lies It is obvious that thermal insulation alone only causes a limited delay the temperature rise can also be achieved on the cold side, and this relatively large wall thicknesses are required. In addition, there are thermal insulation materials with a correspondingly high thermal resistance on the one hand and below the fire temperatures On the other hand, sufficient temperature resistance is not available if one refrains from asbestos, which as a result of its health-endangering effects Possibility not to be used. Mineral fibers, even stone fibers, sinter under the high fire temperatures starting from the hot side together and lifting so their effectiveness relatively quickly with low wall thickness on the hot side as a thermal insulation material, so that relatively large wall thicknesses are required; Farther mineral fibers have a relatively low heat capacity and can therefore use the Temperature rise on the cold side due to own heat absorption with small wall thicknesses delay only insignificantly.

As a material for a layer that stores latent heat can delay the temperature rise on the cold side due to phase transition, especially plaster of paris is in practical use. Thereby the relatively high enthalpy used when the water of crystallization is split off, which takes place from approx. 500 ° C. Here is However, it is disadvantageous that the resulting water vapor with glowing metallic surfaces can react with the formation of hydrogen, and a water vapor atmosphere high Temperatures on the resistance of the mineral fiber insulation materials has negative effects. Furthermore, plaster of paris can be used as a layer for those required in practice Dimensions can only be manipulated in the form of so-called plasterboard panels, whereby a layer of plaster is laminated on both sides with cardboard. The cardboard lamination increases naturally the fire load and promotes the formation of flammable smoldering and decomposition gases, possibly even the formation of water gas in conjunction with released water vapor (CO + H2).

There has therefore also been no lack of attempts to find such latent heat-absorbing Manufacture fire protection zones from other materials that do not have laminations made from organic Substances or the like need and, in the event of a fire, especially none or only develop little water vapor.

For this purpose, sodium metasilicate has become known from DE-OS 30 23 632, a substance that melts in its own crystal water at approx. 480C while absorbing heat and is stable in the molten state. However, the problem here is that the melt has a relatively low viscosity even at the lowest temperatures is formed and of course has the tendency to be in the lower range of available standing room.

; this just completely removes the hot upper area from the Material of the layered fire protection zone is exposed, so that there the temperature practically rises sharply on the cold side. According to the teaching of DE-OS 30 23 632, the sodium metasilicate is said to prevent it from flowing off too quickly in an open-pored support structure in a wettable material, for example granulated Mineral wool, to be embedded. According to a similar teaching of DE-OS 30 22 945 a substance should also be introduced that binds the melt and with this forms a doughy or solid mass. However, it has been shown that with such measures the the melt flow is somewhat delayed but cannot be prevented to a sufficient extent. About that In addition, the low melting point of sodium metasilicate of 50 ° C, which is also annoying can be achieved without fire under unfavorable influences, so that in the course Over time, even without the outbreak of fire, melt repeatedly forms and in the floor area can accumulate, so that in the event of an actual fire the fire resistance can already be greatly reduced in the upper area of the wall element.

In contrast, the invention is based on the object of a wall element to create the genre specified in the preamble of claim 1, which in combination with mineral fiber insulation layers a high fire resistance class such as F90 according to DIN 4102, Part 5 can easily be achieved with a relatively small building thickness.

This task is solved by the characteristic features of claim 1.

It is through the use of exclusively inorganic substances First of all, it is ensured that there are no oranic substances that could be used in the event of a fire could generate flammable and / or toxic gases. The decomposition of the granules Carbonatic rock of the alkaline earth metals does not begin in the event of a fire until around 500 0C with decarbonation, whereby the carbonic acid is made from the salt of carbonic acid <CO2) is split off. This is a strongly endothermic reaction that occurs as a reaction product a solid, hard-to-melt oxide and carbon dioxide, i.e. a non-flammable one Gas yields. Limestone (calcium carbonate) in particular is used as carbonate rock and dolomite (calcium magnesium carbonate) in question, which are inexpensive in large quantities be available. In principle, other carbonatic rocks are also the Alkaline earth metals can be used, such as mineral barium carbonate (Witherit), However, this is usually for practical and price reasons compared to limestone or dolomite will not be preferred. In special applications, however, With Witherit, good shielding against ionizing radiation can also be achieved so that there is also a radiation protection effect.

So it can be the carbonates of the alkaline earth metals alone or in a mixture are used, calcium, magnesium and barium carbonate being preferred. Calcium and magnesium carbonate and mixtures thereof are particularly preferred.

Limestone or dolomite become burnt during decarbonation Magnesia or burnt lime (calcium oxide) decomposes, i.e. to oxides that are known as Refractory materials are known and therefore have excellent fire resistance.

In addition to the use of the alkaline earth carbonates mentioned above also the use of alkali carbonates, for example sodium or potassium carbonate, conceivable, which is not usually the case with mineral fibers because of their highly alkaline properties be used, as this attacks the surface of the mineral fibers. However, if the surface of the mineral fibers with an alkali-resistant coating are provided, or for other reasons no harmful interactions are feared, soda and / or potash can also be used advantageously, the binders mentioned below are also used here can.

The granules of dolomite or limestone are inorganic Bound with binding agent, so it retains its mechanical integrity up to high temperatures into it, so that any settling phenomena or the like avoided are. The conversion to the corresponding oxides even results in a certain swelling effect, so that the resulting oxides as refractory materials are able to neighboring To fill cavities by melting away or caking together of mineral fibers have arisen. There is no dehydration and the only gas is Free of carbon dioxide, which tends to cause fire to suffocate. In fire tests it has actually been shown that test flame lances with which the emergence of flammable Gases is examined, blown out literally by the escaping carbon dioxide will.

The binder is of particular importance if it is avoided is intended to ensure that the binding agent in turn decomposes to form flammable and / or toxic substances will.

Hydraulic binders have proven to be particularly suitable in this regard like portland cement. When using Portland cement, or other alkaline hydraulic binders, however, is a contact with Avoid mineral fibers as long as the binder is not completely set and preferably also aged.

So alkaline hydraulic binders like Portland cement are coming - if not harmful interactions, as in the case of a carbonatic use Rocks of alkali metals, excluded in other ways -then in question, when the zones or layers are spaced apart in a wall construction are or, in the case of a composite panel, already on the part of the carbonatic Gesture granulate with prefabricated, bound and best-aged bodies which is subsequently worked with the prefabricated insulation layers made of mineral fibers be joined together by mechanical connection.

As in terms of manufacturing and application technology advantageous Magnesia binders in the form of magnesium oxychloride have also proven to be hydraulic binders or magnesium oxysulphate, i.e. a reaction product of MgO with MgC12 or MqS04, proven. These bind relatively quickly and store a certain amount of crystal water and do not attack the mineral fibers before they are set, since they are not alkaline are. In addition, these binders are waterproof.

In the event of fire, magnesium oxychloride containing water of crystallization is converted into anhydrous magnesium oxychloride in an endothermic reaction at temperatures between 1500 C and 4000 C: In this case, water of crystallization is released, but only in a relatively small amount in accordance with the relatively small amount of binder of between 5 and 25% by weight, preferably between 5 and 15% by weight in the fire protection zone.

A further conversion to magnesium oxide and hydrochloric acid takes place between around 3500 C and 6000 C: The released hydrochloric acid reacts immediately with the calcium carbonate present in the granulate, converting it to calcium chloride and carbon dioxide: This reaction is also endothermic and can therefore store latent heat. The gas produced is in turn carbon dioxide, which is uncritical or advantageous from a fire point of view.

Aluminum sulfate has also proven to be suitable as a thermoplastic binder, which is also added to the carbonate granulate in a proportion of 5 to 25% by weight, preferably between 7 and 15% by weight. Aluminum sulphate also stores considerable amounts of water of crystallization and melts at around 1100 C, whereby not only the melting is an endothermic process, but also between around 1100 C and 1500 C the water of crystallization is split off and expelled in an endothermic reaction: Above about 3500 C the anhydrous aluminum sulphate decomposes with the formation of S03: The aluminum oxide is in the form of loose white flakes, which have good thermal insulation properties and, if the temperature rises further, sinter or bake the granulate so that its mechanical integrity is retained.

The SO3 in turn reacts with the calcium carbonate: So what remains here is calcium sulfate, while the only gas that escapes is carbon dioxide.

In both cases, the hydraulic as well as the thermoplastic Binder, all acidic gases split off due to the excess of dolomite or limestone, since the carbonate is the least stable compound. Both in the decomposition of the binder and in the implementation of the carbonate As a result, only CO is released from rock. All implementation tongues are strongly endothermic, so that overall a high enthalpy to delay the temperature rise is available on the cold side of the wall element. Remain temperature resistant Oxides and small amounts of calcium chloride or calcium sulfate.

The granulate is advantageously in a coarse grain size between 0.5 and 5 mm, preferably between 1 and 3 mm, without any substantial fines. Such a coarse grain results in a large-pored structure of the fire protection zone, whereby the gas separation in the heat takes place more easily and the resulting Carbon dioxide can easily escape through the pores. Furthermore, the plate through the cavities more easily, and the proportion of binder can be relatively low being held.

While the carbonatic stone granulate is mixed with the hydraulic Binder made in a known manner in mixers of conventional design at room temperature can be, when using the thermoplastic binder (he mixing process expediently carried out at an elevated temperature of about 1200 ° C. to 1500 ° C. and should the processing take place hot, so that the thermoplastic properties of the Binders can be used. The bound granulate solidifies when it cools and remains but thermoplastically deformable above about 1100 ° C to 1200 ° C. The process The hydraulic setting of the magnesia binder is on times from 3 hours to adjustable for about 2 days. It can be considerably increased by heating, e.g. microwave drying be abbreviated.

Provided that it is clear in each individual case on which side of the wall element a fire can break out, for example when used as a fire-resistant casing for Components or the like, the fire protection zone should be based on the possible fire facing side of the wall element or in Area of fire in the event of a fire be arranged in the hottest spots; in the case of a fire door, this is the perimeter area of the door leaf as a result of the metal parts present there, which act as thermal bridges. If the fire side is not fixed beforehand, which is the case with fire-retardant doors in the As a rule, the wall element is expedient starting from a central core layer symmetrically constructed. At first it would be obvious, one on each side To have a fire protection zone as the outer layer, sandwiched between a Includes mineral fiber layer as the core layer. However, it has come as a surprise showed that better fire resistance values can be achieved if the middle The core layer with a symmetrical structure is the fire protection zone. The reason for this lies presumably in the fact that the outer insulation layer then facing the respective fire made of mineral fibers, the fire protection zone is first insulated and before the fire is in direct contact with the fire protects so that it is only exposed to the full flame effect later. In each The trap is left with the second insulation layer made of mineral fibers, which is on the cold side is arranged in order to effect the required insulation on the cold side. These The insulation layer is protected by the fire protection zone and can therefore have its insulating effect Fully unfold over a long period of time. It is also possible to use a Train the wall element as a composite panel, with the then directly adjacent Layers are expediently to be connected to one another by means of a binding agent in order to create thermal bridges to be avoided by mechanical connections. It can be hydraulic or thermoplastic Binding agent of the granulate at the same time as binding agent for the neighboring insulation layers made of mineral fibers are used.

In a preferred method of making such a composite panel according to claim 14 the procedure is that first a prefabricated insulation layer from mi Mineral fibers provided and with the binder-containing Granulate is coated before the binding agent sets. In the simplest case then lets the binder harden or set, so that it is not only the Granules connects with each other, but also the surface of the location of the granules with the adjacent mineral fiber surface. For a construction of the composite panel from more than two layers can be on the opposite free side of the granulate Immediately another prefabricated insulation layer made of mineral fibers is placed and in be connected in the appropriate manner, so that the zone of bound granules becomes the core situation.

If necessary, additional granulate zones and / or insulation layers can be added accordingly made of mineral fibers sandwiched together and with the binding agent of the granulate get connected.

A particularly advantageous type of fire retardant door is in claims 15 and 16 specified.

Further details, features and advantages of the present invention emerge from the following description of an embodiment based on FIG Drawing.

It shows Fig. 1 a fire door shown in section with a Wall element according to the invention as an insert, and FIG. 2 shows another embodiment a fire door according to the invention in a representation corresponding to FIG. 1.

The illustrated in the drawing and designated as a whole with 1 The fire door sits in a doorway in the brickwork of a fire-protected room 2 with a bottom 3 with a lower stop 4 and a ceiling 5 with an upper one attack 6. The framework of the fire door 1 is partial at the top at 7 and at the bottom at 8 recognizable. There are also two sheet steel shells 9 and 10. Inside the The space 11 enclosed by the sheet steel shells is a wall element according to the invention 13 arranged. At 12 is a door closer not forming the subject of the invention indicated schematically.

The wall element 13, which is used as an insert between the sheet steel shells 9 and 10 of the fire door 1 is used, is symmetrical in the example Structure of a core layer 14, each with an outer layer 15 on both sides of the Core layer 14. The outer layers 15 consist of mineral fibers, in particular stone fibers, and form insulating layers 16. The core layer 14 of the composite panel Wall element 13 is designed as a fire protection zone 17 and consists of granules 18, the grains of which are denoted by 19 in the enlarged view and indicated binders are connected to one another. The granulate 18 may im Example case dolomite, and the binder 19 is a hydraulic binder in Be in the form of magnesium oxychloride, as was explained in detail in the introduction. In a manner not visible in the drawing, the binding agent 19 also lies on the surfaces the fire protection zone 17, and thus binds the adjacent mineral fibers of the insulation layers 16.

In the embodiment of FIG. 2, the same parts as in the Embodiment according to FIG. 1 with the same and analogous parts with corresponding reference numerals, however, designated by the subscript "a", so that a more detailed explanation of these parts can be dispensed with to avoid repetitions.

The fire door according to FIG. 2 differs from that according to FIG. 1 in particular in that in the peripheral area on the edge the door leaf additional fire protection zones 21 are arranged. The fire protection zones 21 are used to achieve a special protection of the door frame area, as here in particular the metal parts of the framework 7a and 8a act as thermal bridges, whereby these areas are exposed to a particular heat load in the event of a fire. The consequence of this is on the one hand the fact that the mineral fibers there are special can sinter together quickly and thereby quickly lose their thermal insulation properties and on the other hand that the door frame can warp, creating gaps between the door frame and the door jamb, so that flames then occur through these gaps - indicated at 20 - can pass through. The big advantage of the fire protection zones 21 lies in the fact that the material of these zones by its early endothermic reaction to a certain extent the framework cools down, so that in this way it is still too quick Temperature rise on the cold side can be avoided.

As a comparison of the representation in FIGS. 1 and 2 illustrates, is in the embodiment of FIG. 2, the thickness of the core layer 14a, which the Forms fire protection zone 17a, selected lower, but such a thinner training would also be entirely possible in the embodiment according to FIG. In the embodiment According to FIG. 2, however, the fire protection zone 17a could also if necessary completely omitted if a sufficient thickness of the leaf is available. Also in In this case, the fire protection zones 21 would be one in the peripheral area of the door leaf there then certainly to be expected rapid temperature rise on the cold side due to the currents according to arrows 20 and the good thermal conductivity of the framework 7a, 8a prevent.

The fire protection zones 21 can be used with the entire wall element 13a Formation of an overall prefabricated prefabricated collar plate and be connected. Alternatively, however, the wall element 13a can also be used without the fire protection zones 21 inserted into the open door leaf and then a corresponding filling at the edge be made with the granules 18 to form the fire protection zones 21, after which the door leaf is closed and finished. In this case, if necessary no binding agent 19 for binding the granulate 18 in the fire protection zones 21 but a binding agent there provides greater security against Sedimentation of the granules.

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Claims (16)

Claims 1. geuerwiderstandsfahiges, the heat transfer reducing Wall element (13; 13a), in particular as an insert for a fire-retardant door (1; la), with at least one Dämmlaqe (16; 16a) made of bound mineral fibers, which with at least a fire protection zone (17; 17a, 21) made of anoraanic material in the form of granules (18) is combined, the at least one endothermic reaction at elevated temperature or phase transition, characterized in that the material of the fire protection zone (17; 17a, 21) is carbonate rock of the alkali or alkaline earth metals, and that the granules (18) of the fire protection layer (17; 17a, 21) by an inorganic Binder (19) is bound. 2. Wall element according to claim 1, characterized in that the insulating layers (16; 16a) and the fire protection zones (17; 17a, 21) to form a composite panel are arranged directly adjacent to one another. 3. Wall element according to claim 2, characterized in that the insulating layers (16; 16a) and the fire protection zones (17; 17a, 21) by means of a binding agent (19) are connected to each other. 4. Wall element according to claim 3, characterized in that the the Insulating layers (16; 16a) and fire protection zones (17: 17a, 21) holding the composite panel Binder is the binder (19) of the fire protection zone (17; 17a, 21). 5. Wall element according to one of claims 1 to 4, characterized in that that the fire protection zone (17; 17a, 21) on the side facing the possible fire of the wall element (13; 13a), in particular arranged at the hottest points in the event of a fire is. 6. Wall element according to one of claims 1 to 5, characterized in that that the wall element (13: 13a) starting from a central core layer (14t 14a) is symmetrical is constructed. 7. Wall element according to claim 6, characterized by the fire protection zone (17; 17a) as the core layer (14: 14a). 8. Wall element according to one of claims 1 to 7, characterized in that that the granulate (18) of the fire protection zone (17t 17a, 21) is dolomite or limestone. 9. Wall element according to one of claims 1 to 8, characterized in that that the granules (18) of the fire protection zone (17t 17a, 21) in a grain size between about 0.5 mm and 5 mm, preferably between about 1 mm and 3 mm, and substantially has no fines. 10. Wall element according to one of claims 1 to 9, characterized in that that the binder (19) is a hydraulic binder based on magnesium oxychloride or magnesium oxysulfate. 11. Wall element according to claim 10, characterized in that the Binder (19) in amounts between 5% by weight and 25% by weight, preferably between 5 wt .-% and 15 wt .-% is contained in the fire protection zone (17; 17a, 21). 12. Wall element according to one of claims 1 to 9, characterized in that that the binder (19) is a thermoplastic binder based on aluminum sulfate is. 13. Wall element according to claim 12, characterized in that the Binder (19) in amounts between 5% by weight and 25% by weight, preferably between 7% by weight and 15% by weight is contained in the fire protection zone (17; 17a, 21). 14 Method for producing a wall element according to at least one of claims 4 to 13, in the form of a multilayer composite panel, characterized in that - That a prefabricated layer of bound mineral fibers with the binder-containing Granules to form the fire protection layer before setting or Curing of the binder is coated, - that optionally the layer of the binder-containing granulate with another prefabricated one Layer of bound mineral fibers is covered on the free side as well as approximately desired further shift made of binder-containing granules and / or prefabricated layers of mineral fibers alternating in a corresponding manner are applied, and - that one then that in the granules as well as between the granules and binders located in the prefabricated layers of bound mineral fibers harden or can set. 15. Fire retardant door with one door leaf - with one in particular metallic framework (7, 8; 7a, 8a), - with sheet metal shells carried by the framework (9, 10; 9a, 10a) as the outer jacket and - with one enclosed between the sheet metal shells Insert made of fire protection material, characterized in that the insert is a wall element (13, 13a) according to at least one of claims 1 to 14. 16. Door in particular according to claim 15, characterized in that the wall element (13a) is arranged at a distance from the framework (7a, 8a) and the gap there with the carbonatic rock granulate of the alkali or alkaline earth metals is filled to form a fire protection zone (21).