CS267836B1 - Filler mixture for fire protection - Google Patents

Abstract

Sniš na Vázl mineral and intumescent fillers are intended for the preparation of fire-resistant friction seals, inserts and backfills for electrical lines and equipment. It consists of mineral and intumescent granular fillers reduced in the prescribed ratio with metal dust. The mixture has satisfactory thermal conductivity at normal temperatures, at elevated temperatures the individual components react with each other and create a perfectly compressive and thermally insulating compact material.

Description

The invention relates to a mixture of fillers for fire sealing and backfilling of cable and electrical distribution lines and equipment, consisting of a mineral and intumescent filler.

One of the main causes * of rapid fire propagation in power plants is especially all-plastic cable insulation. Despite all the efforts of manufacturers who try to reduce flammability with various interventions in polymeric materials, millions of damages occur every year due to electrical short circuits in the lines on cable trays or switchboards. cases where it occurs. However, Tc is very difficult because flammable gaseous monomer products are usually released from the polymer insulation at elevated temperatures and the flame therefore spreads very rapidly. Therefore, the most common way to limit the spread of flame over cable insulation is a protective coating, which forms an airtight layer on the surface of the insulation, preventing the access of air. If there is a short circuit in such a line, the fire will not start because the fire cannot spread. However, this method is very expensive and is therefore used only in the most important and most exposed parts of the divorce. In other cases, it is mainly used for structural and technological modifications and construction interventions in the routing of routes, which also include cable glands, partitions and backfills. The main disadvantage of all these systems is the high workload, but the technical difficulties arising from the need to separate the partitions already completed cable routes and equipment and perform wet construction processes in places where these processes can easily damage the already installed knowledge. This actually creates the cause of the future defect right during construction. For this reason, various types of fire-fighting products for the construction of the so-called dry, mounted partitions, eg according to MS. AO 243 080 also. The principle is that the individual building elements, e.g. flexible bags made of incombustible material _row are stored on the line and is · formed therefrom septum leaks are then in a fire sealing of foam that is formed from an intumescent ingredients that these elements contain. Although these polymer-based or mineral-based elements have proved their worth and are now widely used, they have certain disadvantages. The main disadvantage is the fact that ee is always a thermal insulation material, which is necessary with regard to the requirement of protection against flame transfer, and therefore at the points of passage of the cable thus formed by the wall of the line is heated above the allowable limit. However, Tin re-creates the focus of a possible fire source. Apart from tc-, it was found that these inserts foam into the gaps only in places where they are affected by elevated temperature on the surface, which is sufficient in most cases, but in cases where these partitions are placed in vertical shafts or in places of increased air flow. foaming may not always be reliable.

The above-mentioned problems are substantially eliminated by the fire-sealing and backfill composition according to the invention, consisting of a mineral and intumescent filler. The essence of the invention consists in that in a mixture of 70 to 80 parts by weight of granular mineral filler and 23 to 40 parts by weight of intumescent filler, consisting of 3 to 5 parts by weight of hexanethylenetetramine or nelamine, 8 to 15 parts by weight of ammonium phosphate, 6 to 12 parts by weight of pentaerythritol and 4 to 8 parts by weight of dextrin, starch or carboxymethylcellulose add 1 to 10 parts by weight. parts of metal, preferably aluminum dust.

The advantage of the mixture according to the invention is that the metal dust, which is very light, especially in the case of aluminum, wraps up and permeates the additive mixture when thoroughly mixed, thereby increasing its thermal conductivity without compromising its own, ie insulating, insulating function. seal. Another significant advantage is that in case of fire, resp. at elevated temperatures there is a better heat distribution even to places that are not immediately affected by the flame, which results in very good foaming of unreacted foamable particles.

CS 267 836 Bl

Hernia tests have shown that the function of the additive is more than doubled by the addition of metal dust. According to previous findings, an exothermic reaction between the expandable mixture and the metal occurs apparently within the mixture at elevated temperatures. The exact mechanism of this reaction is not yet entirely clear, but the important thing is that the efficiency of the mixture thus prepared is significantly improved. Mino are completely removed from the thermal insulation points on the cable duct in the sections where partitions made of these materials are built.

Although it has been found that a number of metal powders can be used as additives in the mixture, aluminum has proven to be the most suitable, both in terms of low light weight and because it is produced in very fine to dusty particles, which is for thorough homogenization. very important, especially since heavier particles could separate during vibrations generated during traffic.

The different proportions of foamable components in the mixture depend on the type of mineral filler used, and the higher the proportion of fine fractions in the mineral base of the filler, the more foamable components must be added to achieve the desired effect. The more then there must be metal dust.

Exemplary compositions of the filler mixture for fire seals according to the invention are given in the following examples.

Example 1

Siege mix: 75 3 10 6 4 1 parts by weight of silica sand with a grain size of 0,4 to 4 mm parts by weight of urotropin parts by weight of ammonium phosphate parts by weight of pentol (pentaerythritol) parts by weight of dextrin hm.díl aluminum powder Example 2 Siege mix: 70 3 12 9 6 2 weight parts weight parts weight parts weight parts weight parts weight parts ground grain of limestone from melamine ammonium phosphate pentaerythritol carboxymethylcellulose. aluminum dust C, 2 up to 2 mm Example 3 Ingredients mix: 79 4 15 12 8 3 weight parts weight parts weight parts weight parts weight parts weight parts ground grain of limestone from urotropine ammonium phosphate pentaerythritol dextrin aluminum dust 0.1 up to 2 nn Example 4 Ingredients mixes: 74 5 15 12 8 10 hm.dílů hm.dílů hm.dílů hm.dílů hm.dílů hm.dílů ground limestone as in e.g. urotropin ammonium phosphate pentaerythritol starch iron dust 3

CS 267 836 Bl

The mixture according to the invention is suitable for filling fireproof sealing gaskets, for backfilling of metal and non-ferrous gutters, into electrical switchboards and the like.

Claims (1)

BACKGROUND OF THE INVENTION Filler for fire seals and backfills consisting of mineral and intunescent filler, characterized in that it consists of 70 to 80 parts by weight of granular mineral filler and 23 to 40 parts by weight of intumescent filler, consisting of 3 to 5 parts by weight of hexanethylenetetranine, 8 to 15 parts of ammonium phosphate, 6 to 12 parts of pentaerythritol and 4 to 8 parts of dextrin, starch other than carboxymethylcellulose, to which 1 to 10 parts of metal, preferably aluminum powder, are added.