RU2265468C2 - Combined fire-extinguishing composition and method of preparation - Google Patents

Abstract

FIELD: fire-fighting, particularly fire-extinguishing compositions.

SUBSTANCE: fire-extinguishing composition comprises heptaflouropropane used as retarder and taken in amount of 95-99.5% by weight and potassium formate used as fire inhibitor and taken in amount of 0.5-5.0% by weight. Method of above fire-extinguishing composition preparation involves supplying gaseous heptaflouropropane under pressure of not less than 3 MPa or gaseous heptaflouropropane cooled up to -17°C or to lower temperature in tank filled with potassium formate. The tank is installed on swinging device. Heptaflouropropane is supplied so that predetermined quantitative component ratio is maintained.

EFFECT: increased fire-fighting ability, reduced toxicity and cost of the composition.

2 cl, 1 tbl

Description

The invention relates to combined fire extinguishing compositions for fire extinguishing based on R227 freon (C ₃ F ₇ H), combining the properties of substances that phlegmatize and inhibit combustion. Such combined formulations are known containing phlegmatizers (CO ₂ , Na, fluorine-containing freons such as CF ₃ H, C ₂ F ₅ H) and homogeneous inhibitors - bromine, iodine-containing freons (A.N. Baratov, E.N. Ivanov “Fire fighting in chemical industry. "M., Chemistry, 1979). This invention provides for the combination of R 227 freon with a heterogeneous inhibitor, formic acid potassium (potassium formate, KHCO ₂ ), with a quantitative ratio of 95-99.5% (mass.) C ₃ F ₇ N and 0.5-5% (mass .) salt.

The prototype of this invention is the homogeneous composition TFM-18I, containing 90% (mass.) CF ₃ H and 10% (mass.) CH ₃ J (patent of the Russian Federation No. 2156630 from 02/08/1999). The specified composition is obtained by simple mixing of the components.

The essence of this invention lies in the fact that in the combined fire extinguishing composition combining a phlegmatizer and a combustion inhibitor, the composition contains heptafluoropropane (C ₃ F ₇ H, R227 freon) and a formic acid potassium (KHCO ₂ ) inhibitor in a quantitative ratio as a phlegmatizer (in% (mass.)):

C ₃ F ₇ H - 95-99.5;

KHSO ₂ - 0.5-5.0,

and in a method for preparing a combined fire extinguishing composition, comprising mixing the components in an airtight vessel mounted on a swinging device made, for example, in the form of a “drunken barrel”, a predetermined amount of powdered formic acid potassium is placed and then gaseous heptafluoropropane is supplied under a pressure of at least 3 MPa or when it is cooled below minus 17 ° C in such a way that a quantitative ratio between C ₃ F ₇ N and KHCO _{2 is} maintained.

The advantage of the proposed composition in comparison with the prototype is the increased fire extinguishing ability of the composition, lower toxicity and cost due to lower price and consumption of the inhibitory component.

Preparation by the claimed method of a combined fire extinguishing composition containing R 227 freon (C ₃ F ₇ H) and potassium formate by mixing the inhibitor with R 227 liquid freon (C ₃ F ₇ H) in an airtight vessel under the pressure of the freon vapor not lower than 3 MPa or at its cooling below minus 17 ° C, allows for uniform mixing of these components.

The results of the experimental determination of the fire extinguishing ability of pure R 227 freon (C ₃ F ₇ H) and the inventive combined composition containing from 0.5 to 5% (mass.) Potassium formate in R 227 freon (C ₃ F ₇ H), which consist in determining the dependence of the quenching of heptane on the concentration and composition of the mixture are given in the table. A positive result was taken with a quenching time of not more than 10 s.

Table The composition of the mixture (in% (mass.)) The concentration of the mixture in air, kg / m ³ Extinguishing Time C ₃ F ₇ H (95) + KHCO ₂ (5) 0.1 102 C ₃ F ₇ H (95) + KHCO ₂ (5) 0.2 eighteen C ₃ F ₇ H (95) + KHCO ₂ (5) 0.22 6 C ₃ F ₇ N (97.5) + KHCO ₂ (2.5) 0.2 79 C ₃ F ₇ N (97.5) + KHCO ₂ (2.5) 0.3 8 C ₃ F ₇ N (99.5) + KHCO ₂ (0.5) 0.25 10 C ₃ F ₇ N (99.5) + KHCO ₂ (0.5) 0.2 12 C ₃ F ₇ N (99.5) + KHCO ₂ (0.5) 0.2 7 C ₃ F ₇ N 0.42 10

From the table it follows that for the mixtures studied, their specific consumption is 0.21-0.25 kg / m ³ , i.e. approximately 45% less consumption of pure R227 freon (C ₃ F ₇ N).

Claims (2)

1. Combined fire extinguishing composition, combining a phlegmatizer and a combustion inhibitor, characterized in that the composition contains heptafluoropropane (C ₃ F ₇ H freon R227) and as an inhibitor formic acid potassium (KHCO ₂ ) in a quantitative ratio, wt. %: C ₃ F ₇ N 95-99.5 KHCO ₂ 0.5-5.0 2. The method of preparation of the combined fire extinguishing composition according to claim 1, comprising mixing the components, characterized in that in a sealed vessel mounted on a swinging device, made, for example, in the form of a “drunken barrel”, a predetermined amount of powdered formic acid potassium is placed and then gaseous heptafluoropropane is supplied under a pressure of at least 3 MPa or when cooling it below (-17) ° C so as to maintain a quantitative ratio between C ₃ F ₇ N and KHCO ₂ according to claim 1.