RU2180255C1 - Fire-extinguishing composition - Google Patents

Abstract

FIELD: fire-extinguishing. SUBSTANCE: invention relates to fire- extinguishing compositions called ozone-safe because of their inertness with respect to ozone layer degradation. Composition contains 1.0 to 2.7 or 25.7 to 99.0% trifluoromethane and 1.0 to 33.9 or 89.0 to 99.0% iodine-containing C1-C2-fluorocarbons. The latter can be mixed with perfluoropropane and perfluorobutane at volume ratio from 1:100 to 100:1. EFFECT: imparted ozone layer inertness. 3 cl, 1 tbl

Description

 The invention relates to compositions used to extinguish fires. In particular, this invention relates to fire extinguishing compositions, called ozone-safe, i.e. not affecting the destruction of the ozone layer.

When extinguishing fires, two important conditions must be observed:
- isolate combustible substances from air,
- Prevent the occurrence or maintenance of the temperature necessary for combustion.

 The oldest way to stop the fire is to flood the burning surfaces with water, but not in all cases of ignition this method is effective, and in some it is even contraindicated, for example, in the case of burning flammable liquids, oil, and electrical equipment. Currently, the use of halogenated carbons as fire extinguishing agents is known. They are used for extinguishing fires in confined spaces equipped with electrical equipment, storage facilities, rare book libraries, pumping units, oil pipelines, etc. In contrast to quenching with water, halogen-containing carbons are very effective in such fires and, in addition, practically do not damage the equipment and protected objects.

 When using fire extinguishing agents, three aspects are taken into account: the toxicity of the agent itself, the toxicity of its decomposition products and the tasks associated with reducing the oxygen content in the atmosphere [Halogen-containing fire extinguishing agents "Teza", St. Petersburg, 1999, p. 73].

Currently, bromine-containing hydrocarbons, such as bromotrifluoromethane (CF ₃ Br or Halon 1301), and bromochlorodifluoromethane (CF ₂ ClBr, or Halon 1211) are used as fire extinguishing agents [Application PCT 01491, cl. A 62 D 1/08, op. 02/06/1990, US patent 5080177, class. 169/46, op. 01/14/1992]. It is believed that bromine-containing agents are highly effective in fighting fires. These substances can be sprayed from portable devices or from automatic systems installed in rooms equipped with fire detectors. However, due to the high ozone-depleting potential, the use of these substances in developed countries has been prohibited by the Montreal Protocol since 1995.

The use of chlorofluorine-containing carbon C ₁ -C _{4 is} common.

Thus, a fire extinguishing composition is known [US patent 5115868, class. 169/45, op. 05/26/1992], including at least 0.5% fluoromethane and at least one of the halogenated carbons selected from the list that includes fluorine and chlorine compounds C ₁ -C ₄ . The propellant used is mainly trifluoromethane CHF ₃ .

Known [Application of Japan 243186, cl. A 62 C 3/00, op. 09/24/96] a fire extinguishing agent composition containing perfluoroalkane. As the main ingredient, this composition contains nitrogen gas and ≤10 vol. % additives selected from compounds:
perfluoroalkane C _a F _{2a + b} , where a = 1-6 and b = 0-2;
fluorocarbon alkane C _n H _m F _p , where n = 1-6, m and p> 1, and m + n is 2n or m + n is 2n + 2, and
fluorohalogenated hydrocarbon alkane C _q H _r F _w Cl _x Br _y I _x , where q = 1-4, r and w are an integer> 1, and at least one of the numbers x, y, z is not 0. The composition is not harmful for humans and the environment.

Known compositions [US patent 5340490, NCI. 252/67, op. 08/23/1994], which includes trifluoromethane and carbon dioxide or trifluoromethane, hexafluoroethane and carbon dioxide. These substances are introduced in an amount of 35-85 wt.% Trifluoromethane and about 15-85 wt.% Carbon dioxide; or 30-43 wt.% hexafluoroethane and from 24 to 37 wt.% carbon dioxide. These compositions have a vapor pressure of about 15 psi at 85 ^o C ± 1 ^o C. Each of the components is ozone-safe, the composition as a whole has a constant indicator of vapor pressure.

The closest formulations are those of WO 93/15794, A 62 D 1/00, op. 08/19/1993. One of the variants of these compositions contains trifluoromethane and iodine-containing fluorocarbons C ₁ -C ₂ in the ranges of 2-10 wt.% And 60-98 wt.%, Respectively.

The same application describes the composition containing trifluoromethane 2-10 wt.% And perfluorocarbon C ₄ in the amount of 60-98%.

 The challenge facing the developers of the proposed composition is to propose a new composition of the fire extinguishing composition having an optimal ratio of incoming ingredients. This composition should also have the following characteristics: to be effective in fire fighting, not to harm human health, to be ozone-safe and not to spoil equipment and materials protected from fire, while at the same time not too expensive. Another objective is the ability to manufacture the composition from currently available components, as well as the possibility of its use on existing fire extinguishing equipment when replacing halons 1301, 1211, 2402.

 The problem is solved by creating a composition that includes the following components: trifluoromethane, iodine-containing fluorocarbon, for example trifluorodiodomethane and / or pentafluorodioethane, tetrafluorodioethane or tetrafluorodiodoethane and perfluoroalkane - decafluorobutane and / or octafluoropropane in the optimal ratio of ingredients.

The essence of the invention lies in the fact that a fire extinguishing composition is developed, including trifluoromethane, characterized in that it further contains iodine-containing fluorocarbons C ₁ -C ₂ with the following components, vol.%:
trifluoromethane from 1.0 to 2.7 and from 25.7 to 99.0,
iodine-containing fluorocarbons C ₁ -C ₂ from 1.0 to 33.9 or from 89.0 to 99.0.

A variant of this extinguishing composition is a composition that contains a mixture of iodine-containing fluorocarbons C ₁ -C ₂ with perfluoroalkanes C ₃ -C ₄ .

The ratio in the mixture of iodine-containing fluorocarbons C ₁ -C ₂ and perfluoroalkanes is from 1: 100 to 100: 1, respectively.

 Differences of the developed composition from the known ones are new combinations and contents of components, allowing to select compositions with the necessary fire extinguishing concentration and vapor pressure.

 Included iodine-containing halocarbons, as well as trifluoromethane, and perfluoroalkanes are ozone-friendly substances; the composition as a whole is also ozone safe.

 The developed composition is non-toxic and belongs to hazard class 4.

 Since all components of the mixture do not contain oxygen, the mixture does not support combustion. All components are characterized by high thermal stability.

 The proposed composition is prepared by any known method, including simple mixing of the components.

 The proposed composition is used on existing fire extinguishing equipment, without its modernization.

Examples of compositions prepared in accordance with the proposed composition and in the specified ratio, and their minimum extinguishing concentrations (volumetric), as well as their vapor pressure above the liquid at 20 ^o C are shown in the table.

Claims (2)

1. Fire extinguishing composition, including trifluoromethane, characterized in that it further comprises iodine-containing fluorocarbons C ₁ -C ₂ at the following content of components, vol. %:
Trifluoromethane - 1.0 - 2.7 or 25.7 - 99.0
Iodine-containing fluorocarbons С ₁ -С ₂ - 1.0 - 33.9 or 89.0 - 99.0
2. Fire extinguishing composition according to claim 1, characterized in that it further comprises C ₃ -C ₄ perfluoroalkanes.  3. Fire extinguishing composition according to claim 2, characterized in that the volume ratio of iodine-containing fluorocarbons and perfluoroalkanes is (1: 100) - (100: 1).

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