RU2225735C2 - Method of production of a combined homogeneous- heterogeneous fir-extinguishing composition - Google Patents

Abstract

FIELD: fire prevention. SUBSTANCE: the invention presents a method of production of a combined homogeneous- heterogeneous fire-extinguishing composition intended for the volumetric fire-extinguishing using a gas composition. The composition is produced by mixing of a saturated solution of potassium iodide in ethanol with fluid chladone at the following ratio (in mass %): fluid chladone - 70-80; a solution of potassium iodide in ethanol - 20-30. The method allows to produce a homogeneous fire-extinguishing composition and also to reduce consumption of a cost expensive chladone. EFFECT: the invention allows to produce a homogeneous fire-extinguishing composition, to reduce consumption of a cost expensive chladone. 1 cl, 1 tbl, 1 dwg

Description

The invention relates to the field of obtaining a combined homogeneous heterogeneous fire extinguishing composition intended for volumetric fire extinguishing by gas compositions.

The most effective means of volumetric fire extinguishing are homogeneous (halogenated hydrocarbons) and heterogeneous (finely divided or aerosolized mineral salts of alkali metals) combustion inhibitors that effectively inhibit reactions in a flame.

Homogeneous inhibitors, along with good operational properties, have the ability to create a low-toxicity extinguishing medium in a protected room, but at the same time they have insufficient efficiency (especially after the prohibition of bromine-containing substances) due to the selective extraction of active centers responsible for the development of the combustion process (mainly atomic hydrogen).

Heterogeneous inhibitors, although they have a more universal interaction with active centers and, as a result, a higher fire extinguishing ability, are significantly inferior to homogeneous inhibitors in their operational properties (limited ability to create a uniform suspension of powders, storage difficulties, etc.; in the case of aerosol formulations, limitations in use due to the high temperature of the aerosol and the danger of an open flame).

Therefore, it seems very promising to create a homogeneous mixture of homogeneous and heterogeneous inhibitors that promises an increase in fire extinguishing ability and performance of such a mixture compared to individual components.

A known method of obtaining a fire extinguishing composition, adopted as a prototype, in which the mixing of homogeneous and heterogeneous inhibitors is carried out mechanically using an ejector device (USSR author's certificate No. 715092 with a priority of 08/11/78).

The disadvantage of this method is the inability to use the resulting fire extinguishing composition for volumetric fire extinguishing and its long-term storage. The combination of homogeneous (chladone) and heterogeneous (powder) inhibitors using an ejector is recommended for manual fire fighting.

The present invention provides for the creation of a single solution of freon (for example, a compound such as perfluorocyclobutane C ₄ F ₈ , perfluorobutane C ₄ F ₁₀ , heptafluoropropane C ₃ F ₇ H, dibromotetrafluoroethane C ₂ F ₄ Br ₂ ) and potassium iodide. To do this, it is proposed to first obtain a saturated solution of potassium iodide in ethanol, after which this solution is mixed with liquid freon at a weight ratio of 70-80 wt.% Freon and 20-30 wt.% Saturated solution of potassium iodide in ethanol. The content of potassium iodide in ethanol in this case is up to 5 wt.%.

The choice of these substances is caused, on the one hand, by the need to use an environmentally friendly and liquid under normal conditions halogenated hydrocarbons as well as a harmless and highly efficient heterogeneous inhibitor as a matrix component. Since potassium iodide, as an inorganic substance, does not directly dissolve in chladone, but is limitedly soluble in ethanol, it is proposed to first prepare a solution of potassium iodide in ethanol, and then mix this solution with chladone. It has been experimentally established that up to 5 wt.% Potassium iodide is dissolved in ethanol.

The table and drawing show the experimentally obtained dependence of the quenching time of burning heptane on the air content of a combined composition containing Freon 114B2 (C ₂ F ₄ Br ₂ ) and a solution of 3.4 wt.% Potassium iodide in ethanol. The tests were carried out in a cylindrical chamber with a volume of 50 l, the air of which was previously evacuated to a residual of about 2 mm Hg. Art. Then, a certain volume (in ml) of a ternary solution consisting of a mixture of Freon 114B2 and KI in C ₂ H ₅ OH was introduced into this chamber. The content of the KI solution in ethanol in the freon was varied so that the ratio between the 114B2 freon and the KI solution in C ₂ H ₅ OH was, wt.%: 90% freon + 10% KI solution in C ₂ H ₅ OH, 80% freon + 20% solution of KI in C ₂ H ₅ OH, 70% HFC + 30% solution of KI in C ₂ H ₅ OH. In the last column for comparison, the result of the quenching with one Freon 114B2 is shown. The results of experiments in which quenching was achieved in no more than 10 s were taken as positive. The results of the experiments are presented in the table.

From the table and drawing it can be seen that the best result is achieved by adding to the chladone 20% solution of KI in ethanol. The KI content in the ternary solution is only 0.03 g or 0.25 wt.%. The reduction in the consumption of expensive Freon 114B2 when extinguishing with a combined solution compared to pure Freon was

Claims (1)

A method of obtaining a homogeneous heterogeneous fire extinguishing composition, comprising mixing a homogeneous and heterogeneous combustion inhibitors, characterized in that a saturated solution of potassium iodide in ethanol is preliminarily prepared, after which the said solution is mixed with liquid chladone in the following weight ratio,%: Liquid Freon 70-80 A solution of potassium iodide in ethanol 20-30

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