Fire extinguishing development directions for liquids based on the foam glass primary layer

Abstract

The combustible liquid modulating parameter was established to predict the foam glass fire-extinguishing layer as the primary means for liquids ensuring reliable fire extinguishing in combination with other fire-extinguishing means. The formation peculiarities and buoyancy indicators of dry and wet foam glass in polar and non-polar liquids (alkanes and alcohols) were investigated. It is shown that the foam glass buoyancy increases with an increase in the liquid density. The foam glass buoyancy in polar and non-polar liquids was described depending on the liquid density by an approximate linear dependence separately for dry and wet foam glass. The deviation from the linear trend is explained by the foam glass different wettability, some alcohols water solubility, and liquid mixtures peculiarities. The buoyancy relation with flash point was established, which works separately for n-alkanes, n-alcohols and glycols, which was described mathematically. A formula was developed to describe the relationship between flash temperatures and the liquids density. Correlations with a fire-extinguishing layer of dry foam glass for molar mass, molecule or cluster length, stoichiometric combustion reaction coefficient, burning rate on a free surface, density, flash point, boiling point, autoignition temperature were studied. The forecasting possibility the dry foam glass fire-extinguishing layer based on the description of flammable liquids clusters has been established. Mathematical dependences were obtained for the dry foam glass fire-extinguishing layer depending on the expected clusters length in the liquid and a similar dependence for flash points. The conditions for effective extinguishing of alcohols and alkanes with dry foam glass have been determined. Different modes of extinguishing hydrocarbons with flash temperatures tfp<28 оС and tfp>28 оС are recommended, based on the primary layer of 6 cm of wet foam glass with a fraction of 1.0–1.5 cm, with the possibility of finalizing the extinguishing, if necessary, with an inorganic gel by spraying components with an application rate of 0.2 g/cm2.