RU2363509C2 - Smothering composition - Google Patents

Abstract

FIELD: means of protection.

SUBSTANCE: invention relates to combined fire-fighting compositions consisting of inhibiting and air-thinning components. Such compositions create synergetic effects on processes originating in flame and feature high-fire-fighting ability. Proposed composition comprising inert gas or mix of inert gases, e.g. nitrogen, carbon dioxide, argon, to inhibit combustion, uses additionally the additive representing cyclic phosphazens (phosphonitrils) of general formula (PNHal₂)_n where n ≥ 3; Hal is atom of chlorine, fluorine, completely or partially halogenated alkyl radicals, the component ratio being as follows: 0 to 99.5 wt % - carbon dioxide, 0.5 to 100 wt % - phosphazen. Ingress of proposed composition into atmosphere in whatever possible amount brings no harmful effects on either ozone layer or Earth climate.

EFFECT: synergetic effect on processes in flame, improved fire-fighting ability.

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Description

The invention relates to combined fire extinguishing compositions consisting of inhibiting and diluting air components. Such compositions create a synergistic effect when exposed to processes occurring in a flame, and are characterized by high fire extinguishing ability.

Combined formulations are known that contain bromine and iodine-containing freons as inhibitors and nitrogen, carbon dioxide and others as diluents (A.N. Baratov. "Burning-Fire-Explosion-Safety", VNIIPO, 2003, p.333 -356). Along with satisfactory fire extinguishing properties and environmental characteristics, these compositions have disadvantages, for example, in the relatively high cost of these compounds. In addition, despite the satisfactory fire extinguishing ability, they are significantly inferior in this indicator to the widely used but environmentally harmful freon 114B2 (C ₂ F ₄ Br ₂ ) and 13B1 (CF ₃ Br).

The prototype of the claimed invention is a fire extinguishing composition (Copyright certificate SU 314530, published 09.21.1971, bulletin No. 28). In this invention, as an inhibitor in a combined composition, dibromotetrafluoroethane or bromotrifluoroethane are proposed for use, the production and use of which are currently prohibited.

The essence of the claimed technical solution lies in the fact that in a composition for volumetric fire extinguishing containing an inert gas or a mixture of inert gases (nitrogen, carbon dioxide, argon) and an additive that inhibits the combustion process, cyclic phosphazenes (phosphonitriles) of the general formula are used as an additive: ( PNHal ₂ ) _n ,

where n≥3;

Hal - an atom of chlorine, fluorine, fully or partially halogen-substituted alkyl radicals;

in the following ratio of components:

0-99.5 wt.% - carbon dioxide;

0.5-100 wt.% - phosphazene.

In the proposed composition, a phosphorus-containing compound of the phosphazene series (cyclic phosphazenes) is used as an inhibitor, and carbon dioxide (CO ₂ ) is used as a diluent.

The use of hexafluorophosphazene (PNF ₂ ) ₃ in an amount of 3 wt.% To carbon dioxide can reduce the minimum extinguishing concentration of carbon dioxide by half.

In this case, the minimum fire extinguishing concentration of hexafluorophosphazene, determined using the Cylinder method, is 1 vol.%.

The results of the determination of fire extinguishing concentrations (OC) of various combinations of these substances during the quenching of n-heptane are given in Table 1. The concentration of the composition at which quenching was achieved in no more than 10 s was taken as OK.

Table 1. Composition, wt.% The concentration of components in the volume in the conditions of the experiments, vol.% Fire extinguishing composition concentration CO ₂ (PNF ₂ ) ₃ CO ₂ (PNF ₂ ) ₃ % g / m ³ 0 one hundred 0 one one 112 97.2 2,8 10 0.05 10.05 200 98.7 1.3 13 0,03 13.03 258.3 one hundred 0 18.00 0 eighteen 354

Analysis of the physicochemical properties of hexafluorocyclotriphosphazene, (PNF ₂ ) ₃ , obtained using the Gaussian 03W quantum mechanical calculation program, as well as using methods developed at the Laboratory of Chemical Atmospheric Physics at the Institute of Chemical Physics of the Russian Academy of Sciences, showed that the ozone-depleting potential (PNF ₂ ) ₃ is zero, the greenhouse potentials HGWP ((PNF ₂ ) ₃ , t) (relative to CFC-11) for time horizons of 20, 100 and 500 years are 6.9 · 10 ^-3 , respectively; 2.8 · 10 ^-3 and 2.5 · 10 ^-3 , and the values of GWP ((PNF ₂ ) ₃ , t) for the same time horizons are equal, respectively, 43.5; 12.9 and 4.0 (see table. 2). This means that the ingress of this substance into the atmosphere in practically unlimited quantities will not do any harm to the ozone layer or the Earth’s climate.

Table 2.
Atmospheric properties of hexafluorocyclotriphosphazene. Chemical ODP Time Hgwp Gwp Hgwp Gwp Hgwp Gwp formula life 20 years 20 years 100 years one hundred 500 years 500 years years years (PNF ₂ ) ₃ 0 0.1 6.9E-3 43.5 2.8E-3 12.9 2,5E-3 4.0

As studies have shown, the preferred composition is based on hexafluorophosphazene (PNF ₂ ) ₃ .

Claims (1)

Composition for volumetric fire extinguishing, containing an inert gas or a mixture of inert gases (nitrogen, carbon dioxide, argon) and an additive that inhibits the combustion process, characterized in that cyclic phosphazenes (phosphonitriles) of the general formula are used as an additive: (PNHal ₂ ) _n ,
where n≥3;
Hal - an atom of chlorine, fluorine, fully or partially halogen-substituted alkyl radicals;
in the following ratio of components:
0-99.5 wt.% - carbon dioxide;
0.5-100 wt.% - phosphazene.