EP1648841A2

EP1648841A2 - Extremely fireproof inorganic foamed plastic body

Info

Publication number: EP1648841A2
Application number: EP04763598A
Authority: EP
Inventors: Herbert Giesemann
Original assignee: Giesemann Herbert
Current assignee: GIESEMANN, FRANKA MICHAELA; SCHAEFER, KARIN ANNA MONIKA
Priority date: 2003-08-01
Filing date: 2004-07-28
Publication date: 2006-04-26
Also published as: WO2005012207A3; WO2005012207A2; ZA200600910B; JP2007500670A; DE10335232A1; CN1863746A; IL173437A0; AU2004260720A1; NO20061010L; KR20060052958A; CA2535200A1; US20060266263A1

Abstract

The invention relates to an extremely fireproof inorganic foamed plastic body, to a method for producing said body and to the use of the latter.

Description

HIGH FIRE-RESISTANT INORGANIC FOAM BODY

The invention relates to a highly refractory inorganic foam body, a process for its production and the use of the foam body.

Rarely has an event like the one in New York on September 11, 2001 rocked the civilized world. At this point, at the latest, it was recognized that people are exposed to fire catastrophes as inmates of skyscrapers.

Both towers of the World Trade Center were built from steel profiles around the late 1980s. Little is known that steel loses its internal strength and collapses in the temperature range of 750 to 800 ° C. The fire temperature was increased by the kerosene thrown from the aircraft into several floors. The steel profiles could not withstand these temperatures.

For the first time, DE 39 23 284 C2 describes a thermal insulation material which can be proven to remain volume-stable for hours in a temperature range of 2100 ° C - the flame temperature of a welding torch. This property is undoubtedly achieved by the mineral composition, quartz powder and sodium silicate, with a density of 50 to 400 kg / m ³ . The low thermal conductivity is caused by the presence of the air cells. But despite the large number of air cells with the very sensitive walls from the broken sensitive mineral material, suitable measures can be used in the inventive product, for example to achieve sufficient abrasion resistance in the peripheral zones.

If a little ammonium hydroxide is poured into an aqueous aluminum salt solution at room temperature, gelatinous hydrogel precipitates from amorphous aluminum oxide, which gradually converts to crystalline aluminum metahydroxide, AIO (OH). The gelatinous precipitate initially formed contains different amounts of water, some of which are absorbed and some of which are chemically bound. Such precipitates can gradually form stoichiometrically well-defined hydroxides. Previously it was assumed that the resulting "aluminum oxide" in the art (still called alumina hydrates) the composition Al ₂ 0 ^• H ₂ O or Al ₂ O 3 ^■ 3 H2O had and thus would be hydrated. However, studies have shown that the precipitates are real hydroxides. From Römpp Chemistry Lexicon - Version 2.0, Stuttgart / New York: Georg Thieme Verlag 1999 knows that AI (OH) ₃ itself can be used as a flame retardant in finely divided form.

The requirements placed on highly refractory foam bodies can be summarized as follows:

1. complete flammability,

2. sufficient mechanical strength,

3. The greatest possible insulation (insulation) when the fire temperature passes to the side that is supposed to protect steel from at least 600 ° C. Thermal insulation materials, for example for the building industry, such as synthetic resin foams, glass and mineral fibers and others are known in this field.

These insulation materials are intended to keep a building's cold temperatures of -30 ° C, for example, or tropical temperatures of +40 ° C to keep room temperatures low. Resin foams burn vigorously with smoke and toxic gases at over 100 ° C, but are still insulating materials (formerly insulating materials).

Even the classic insulation material, mineral fiber, does not withstand fire temperatures of over 1,000 ° C in the long term.

DE 199 09 077 AI relates to a highly refractory inorganic foam body, a process for its production and the use of the foam body.

The object of the invention is to develop new foam bodies, in particular fire protection materials, which are extremely reliable. can protect from these temperature ranges for several hours - for example 4 to 6 hours.

The invention has also set itself the task of solving the problem of using elevators, in particular passenger elevators, continuously for hours in the event of a fire.

In a first embodiment, the present invention relates to a highly refractory inorganic foam body consisting of an at least partially open-celled, foamed and hardened mixture of alkali water glass and aluminum hydroxide as well as one or more fillers from the group aluminum oxides, silicon oxides, alumina cement, rock powder or mixtures thereof with a bulk density in the range of 200 to 900 kg / m ³ .

In this context, cooling means absorbing heat calories. In the case of gypsum, for example, a plate of 1 m ² 15 mm thick should contain 3 liters of crystal water. Vaporizing this amount is said to absorb approximately 8400 kJ or 2000 kcal of energy.

Gypsum normally has a coefficient of thermal conductivity of 2.1 W / mK. The evaporation causes a considerable reduction in the heat transfer in the material.

As shown in Fig. 1 - Test of such a compact gypsum board (small fire shaft test according to DIN 4102) it can be seen that the heat transfer at about 100 ° C is delayed by approx. 20 min, curve b is the course of the standard temperature curve according to DIN 4102 ETK.

According to the gypsum board industry, this cooling effect is based on this evaporation of the chemically bound crystal water molecule

However, curve a also shows that after this 20 min cooling effect, the curve goes up steeply, after about 60 min the temperature on the back is around 400 ° C, i.e. well above the limit of 140 K. Such a plate would be classified as F 30. The result of such a test in a small fire oven according to DIN looks very different for the foam body according to the invention, which contains chemically bound water molecules and in particular aluminum hydroxide as an inorganic powder for liquid glass: in FIG. 2, curve A shows the course of such a foam piece in one 90 mm thick. After 300 min = 5 hours, a temperature of 116 K is reached on the back. The same foam sheet but with a thickness of 70 mm reaches the limit temperature of 142 K on the back after a fire of 200 min. Surprisingly, the temperature on the back drops evenly after this time, a great success of the cooling effect.

The optimal thickness of the inventive foam insulation material will therefore be 80 mm with a presumed result: maximum height after 250 min with 130 K, then continuously decreasing and that is the most impressive of the inventive material.

In other tests with a propane gas flame, it was found that these results are very similar at bulk densities of 200 kg / m ³ to 900 kg / m ³ .

Surprisingly, it has now been found that free and chemically bound water molecules are also present in the mineral foam insulation material according to the invention, in each case half. The free water molecules evaporate at room temperature, accelerated as in DE 39 23 284 C2 at temperatures of, for example, 100 ° C. to 200 ° C. Experience has shown that the cooling effect according to the invention only arises when the crystal water molecules evaporate in the range from about 500 to 700 ° C. This surprisingly favorable result is based not only on the cooling effect of the water of crystallization of the sodium silicate, but on the cooling effect of the aluminum hydroxide and the cooling effect through evaporation of the hydroxide portion of this mineral.

The improvement over DE 39 23 284 C2 is that, according to the invention, the cooling effect by evaporation of the crystal water at high fire temperatures was recognized and used accordingly, but also in the second step by using aluminum hydroxide to increase the evaporation effect of the water molecules.

In the practice of using these foam bodies, in particular as fire protection materials, for example in the construction of skyscrapers, these cladding and cladding materials must meet minimum requirements, such as a perfect aesthetic appearance, high impact strength and / or scratch resistance when cladding steel supports in rooms.

In Germany, the DIN 4102 standard places additional important demands on mechanical strength: The fire protection cladding must withstand a water jet pressure of 2 bar for 1 minute (Section 6.2.10).

The edge zone compression including the tensile reinforcement already mentioned in detail in DE 39 23 284 C2 also has an important function according to the invention. It is the idea of bionics, like a human or animal bone: light on the inside, extreme hardness on the outside. Such a bionic formation of an incombustible insulation material is not possible with other incombustible materials, such as calcium silicate and gypsum board, because of the two factors of the complete absence of air cells and the absence of tensile reinforcements. The foaming chemicals that are occasionally used do not have a mechanical surface hardness either.

All requirements, as fire protection for cladding of steel and reinforced concrete structures, are met by the described innovative fabric developments.

All fire protection materials according to the invention contain sodium / potassium silicates as binders. These bring a very important advantage when used for steel and reinforced concrete cladding in practice: the silicate solutions are the only inorganic refractory adhesive. This makes it particularly easy and efficient to attach to steel surfaces, for example. The steel side receives a coating of the mixture of mineral powder (aluminum hydroxide) and sodium silicate, as does the surface of the inventive fire protection board to be used. Such an attachment, for example below a sheet steel ceiling in this way, is immediately adhesive and does not need to be supported.

The foam bodies according to the invention, for example fire protection panels, also have excellent airborne sound absorption. The mineral, open-cell structure already results in efficient absorption of the airborne sound waves that occur. This effect can be achieved, for example, by a refractory perforated plate or by milling the surface into small pyramids, as shown in FIG. 3. In contrast to windows, the dimensions of doors and fire protection doors can be standardized. 4, the construction of a generally usable incombustible and highly fire-resistant inner and outer door is described. But not only in the event of a fire, the foam according to the invention has a cooling effect, but is also completely water and water vapor tight for wet rooms, impact and scratch resistant, veneerable on both sides, glazable and bulletproof.

The compact door leaf 1 consists of the foam according to the invention, which contains a reinforcement 2 that is resistant to bending tension. The frame 3 has the same properties as the door leaf 1 (cheaper than the most common steel profile due to the fire behavior, heat conduction, etc.). The masonry 4 and the interior plaster 5 are also shown.

A special construction for a fire door according to the invention instead of a sheet steel door is shown in FIG. 5. The two thin mineral intermediate plates 3a, 3b made of the foam bodies according to the invention ensure cooling. The special effect of a strong, the heat transfer efficiency is seen preventing ^• that the water molecules penetrate into the mineral fiber zones and continue to absorb these fiber zones by the cooling calories during evaporation.

The outer shaping composite panels la, lb according to the invention with cooling effect are welded to frame panels 7 (1 to 1.5 mm) in a pyramid shape. Mineral fiber plates 6a, 6b are located between see two layers of foam body according to the invention. The reference numerals 4, 5 and 6 have the same meaning as in Fig. 6. The production of fire protection cladding is a particularly important area of the present invention, in particular the fire protection of steel and reinforced concrete columns in rooms. The surface of these claddings must be mechanically strong, in particular, to withstand the pressure of the extinguishing water jet on the surfaces at 2 bar.

The application examples show that with the fire protection materials according to the invention, steel ceilings and steel profiles withstand temperatures of 1050 to 1200 ° C for a duration of 4 to 6 hours depending on their strength, because they can resist the temperature of a welding torch up to 2100 ° C and thereby the important cooling effect exhibit.

In any case, the use and the constructive design of the fire protection insulation materials according to the invention in these and other constructive designs achieve the highest security levels. According to the invention, a high level of security in the construction and in the conversion of skyscrapers is possible with the use and correct use in the usual wall thicknesses of the fire protection materials according to the invention.

All high-rise buildings, skyscrapers or similar buildings have stairwells, especially emergency stairwells in the event of a fire, so that people can get outside.

But even if a high-rise building has several emergency staircases, it seems unreasonable that every person, for example, 100 floors can descend in a staircase and that these thousands of people can still find space to walk in a stairwell.

The most important problem is seen in the fact that lifts, especially passenger lifts, can be used indefinitely even in the event of a fire.

Elevators always move in an elevator shaft and since low-voltage cables are housed in this shaft, a temperature of 60 ° C should not be exceeded in the event of a fire. As a result, the entire shaft that goes through all floors must be covered with thermal insulation so that the interior does not exceed 60 ° C.

The all-round covering with highly refractory insulating materials on the elevator shafts is solved with the inventive foam in an extremely reliable manner. This is currently not possible worldwide with any other insulation material.

The greatest obstacle to the goal of always using elevators even in the event of a fire is the doors on all floors, which are always opened as sliding doors to enter the elevator shafts. In practice, these sliding doors are made of sheet steel, including stainless steel sheet. Steel now has an unfavorable coefficient of thermal conductivity of 45 to 70 W / mK depending on the alloy. If a fire breaks out, this means that the sliding doors transmit the fire heat to the back of the door relatively quickly. This physical effect does not change if the sheet metal construction is similar to that of the fire doors in high-rise buildings. inside is filled with a thermal insulation material such as mineral fibers.

With a fire on one floor, flue gases and toxic gases mostly develop from the burning plastics. j Sliding doors, however, have to be moved constantly, so they can never close to the elevator shaft in a smoke and gas tight manner. In addition, each vehicle basket exerts a strong pull in the shaft when moving downwards, as upwards; Smoke would therefore be increasingly sucked in. The conclusion is that this construction can easily be sealed smoke-tight by easily moving sliding doors in the event of a fire.

A design option for high-fire-resistant end doors in the floor as well as in the car cabins is shown in FIG. 6, in which the composite material according to the invention for the frame shown here has an F 120 value in the test, for example of 18 mm.

The mineral composite material 1 with cooling effect according to the invention has a tension reinforcement 2. The stainless steel sheets 8 are welded onto the composite frame with the sodium silicate.

The proposal shown in Fig. 6 has the following advantages:

(1) By replacing the steel frame with the composite material with a coefficient of thermal conductivity of 1.2 W / mK, the fire temperature is conducted to the rear with a considerable delay.

(2) By exchanging the mineral fiber for mineral foam insulation with a cooling effect, i.e. F 120 value, the passage of heat radiation is almost completely avoided. An air gap in these sliding doors, however, can hardly be avoided. This must be about 2 mm.

The manufacturers of the lifts are usually of the opinion that the surfaces of these doors, at least where they come into contact with people, must be made of steel or stainless steel sheets.

According to the invention, a new solution to this heat and flue gas problem, as shown in FIG. 7, is presented. In the event of a floor fire, heat and / or smoke sensors trigger the lowering of a door-like molded body which was produced from the heat protection materials according to the invention. As shown in FIG. 7, both problems were optimally solved with this construction and the materials according to the invention: complete stopping of the heat transfer for many hours and complete smoke density at all edge zones of this fire protection insulating body, both vertically and horizontally.

7 shows an elevator according to the invention. A conventional vehicle basket 9 made of steel is located in a conventional shell construction 10 made of reinforced or reinforced concrete. In the event of a fire, cladding this structural wall with incombustible thermal insulation materials according to the present invention ensures that the inside temperature of the continuous elevator shaft does not exceed a temperature of 50 to 60 ° C. even after hours. The inner sliding doors 11, 11a, 11b and 11c of the vehicle cage delimit the elevator shaft inwards, while the floor-side sliding doors 12, 12a, 12b and 12c form the end of the shaft to the building. The fire-resistant closure according to the invention is formed by the highly refractory inorganic foam bodies according to the present invention. If necessary, this is set by sensors in the event of a fire. The lateral smoke-tight connections 14, 14a are optionally pressed against the mechanical guides by thin steel sheets 15, 15a.

The progress lies primarily in the fact that, in contrast to the always flexible sliding doors, this safety construction against heat, smoke and all gases is only used automatically in the event of a fire and therefore has the highest level of security, and secondly that for this inventive construction At the same time, fire protection insulation materials have been developed that achieve an optimum level of protection, for example through the cooling effect. Thirdly, the advantage is that this design idea can be implemented at any time in existing skyscrapers without disrupting the daily operation of the elevators. For the reasons mentioned above, it would not be possible to replace the existing doors with any other smoke-tight construction anyway.

A variant of the above-mentioned construction idea is shown in FIG. 8.

A shell structure 10 of a vehicle shaft is adequately thermally protected on the ceiling by a thermal and flame-resistant cladding 6. Triggered by a smoke and / or temperature sensor is the fire and gas-tight end body 1, la, lb, which is already completely smoke-proof due to its own weight at 16a and 16b, lowered. A gap-like opening 17 for inserting a handy object ensures that the body is pushed upwards, for example if the fire brigade wants to get to the source of the fire with hoses.

This inventive proposal is of particular importance; it is the job of the firefighters to get to the source of the fire as quickly as possible after the outbreak of a fire. Carrying hoses up over stairwells is almost unreasonable. Hence the suggestion: water pipes are led upwards in the cool, fire-resistant elevator shafts for connection to short hoses on each floor.

In the event of a fire, the firefighters could successfully use a water jet to fight the local source of the fire as quickly as possible after entering a skyscraper.

In high-rise buildings and skyscrapers, the entrance halls in which the passenger lifts end usually have room heights of over 4.0 m. Here there is the possibility of arranging the molded body according to the invention against fire heat and flue gases from only one piece, while such a multi-stage arrangement can be provided for a room height of less than 3.10 m.

The interior doors in high-rise buildings, in particular for use as offices, are made of wood-based materials and are the escape routes to the stairs or elevators. As is well known, cellulose now ignites at over 150 ° C and this temperature is exceeded according to DIN 4102 after a fire in the room for 1 minute.

The door to the hallway quickly catches fire and the smoke smoke moves into the escape route. If this room is close to the emergency staircase, the people who want to escape from the other rooms are hindered or poisoned by the smoke zone within the emergency corridor.

It is therefore proposed, at least in the case of new buildings of skyscrapers, to provide these doors not only incombustible, but also highly fire-resistant in F30 to F60. If such a door, at least the door leaf is manufactured in standard sizes, this is not only ecologically correct, but also economically feasible.

With the help of the idea according to the invention, the second weak point in the room in the event of a fire, the window construction, can also be reliably protected in the same way, because the flames are blowing upwards. After lowering a fire apron from the foam body according to the invention, not only is the fire localized, but the particularly dangerous flashover into the upper floors is reliably and efficiently avoided.

It is certain that the development of the highly refractory materials, in particular the cooling effect and in connection with these materials, achieves the highest level of safety for everyone in high-rise buildings and skyscrapers. In a further preferred embodiment of the present invention, the foam body is characterized in that it contains aluminum hydroxide in an amount of 60 to 80% by weight and in the powder dimensions (polymodal grain size distribution) is mixed.

If the amount of aluminum hydroxide powder chosen is lower, the mineral mixture has less compressive strength. If, on the other hand, the amount I of aluminum hydroxide is chosen too large, the mineral mixture lacks the internal adhesive liquid glass.

A further embodiment of the present invention consists in a process for producing the above-mentioned foam bodies, wherein a mixture of alkali water glass and optionally a filler from the group consisting of aluminum oxides, silicon oxides, alumina cement, stone powder or mixtures thereof, which furthermore contains aluminum hydroxide, with a blowing agent added and heated at a temperature in the range of 200 to 300 ° C.

Azodicarbonamide is particularly preferably used as a blowing agent in the sense of the present invention.

Another embodiment of the present invention is the use of the above-mentioned foam bodies for the production of refractory components in building construction, civil engineering and civil engineering.

In the sense of the present invention, it is particularly preferred to use the foam bodies according to the invention for fire and smoke-tight sealing of elevator shafts or elevator doors. In in the same way it is also possible to produce and use fire protection doors, fire protection cladding, data backup cabinets and rooms, disk inserts, fastenings, fire protection closures, cable and pipe closures, smoke control flaps, fire aprons, etc.

Claims

claims:

1. Highly refractory inorganic foam body consisting of an at least partially open-celled, heated and foamed and hardened mixture of alkali water glass and aluminum hydroxide and one or more fillers from the group consisting of aluminum oxides, silicon oxides, alumina cement, rock flour or mixtures thereof with a bulk density in the range of 200 to 900 kg / m ³ .

2. Foam body according to claim 1, characterized in that it contains aluminum hydroxide in an amount of 60 to 80 wt.%

3. A method for producing a foam body according to claim 1 or 2, wherein a mixture of alkali water glass and optionally a filler from the group consisting of aluminum oxides, silicon oxides, alumina cement, rock flour or mixtures thereof, which further contains aluminum hydroxide, is mixed with a blowing agent and heated at a temperature in the range of 200 to 300 ° C.

4. The method according to claim 3, characterized in that azodicarbonamide is used as blowing agent.

5. Use of a foam body according to one of claims 1 to 4 for the manufacture of refractory components in building construction, civil engineering or civil engineering.

6. Use according to claim 5 for the manufacture of fire protection doors, fire protection cladding, in particular in elevator shafts and elevator doors.