STUDY OF DESORPTION FROM VERMICULITE CAVITIES OF EXTINGUISHING SALTS IN FIRE EXTINGUISHING AND FIRE PREVENTION MEANS

Abstract

A study of the characteristics of the desorption of fire-extinguishing salts from the cavities of highly porous media in means intended primarily for extinguishing fires of flammable liquids spilled on large areas of the surface of reservoirs and for preventing the spread of fires on peatlands was conducted. The requirements for porous media and fire-extinguishing salt are defined. The choice of expanded vermiculite as a carrier material, which has a low bulk density, is chemically inert, heat-resistant, non-flammable, does not release harmful substances when in contact with fire, has a significant volume of open pores, acceptable economic and ecological characteristics, is justified. The choice of ammonium salts and phosphoric acid as a combustion inhibitor is justified. The absence of decomposition at temperatures up to 800 °C was proven by heating the original swollen vermiculite. It is shown that when the temperature rises to 800 °C, the fire-extinguishing salt immobilized in the pores of vermiculite decomposes in less than 10 minutes and comes out of the cavity of the agent and is ready to stop burning by the physico-chemical inhibition mechanism. The effect of the brand of vermiculite and the structure of the salt on the effective extraction of combustion-inhibiting components from the porous carrier is shown. When analyzing the effectiveness, a method of calculating phosphorus compounds from immobilized vermiculite is proposed. It was determined that impregnated vermiculite brand FINE UE releases more inhibitory substance in terms of metaphosphoric acid than other brands even with a lower degree of immobilization of ammonium phosphate. The conducted experimental study of the efficiency of mass loss through the selection of fire-extinguishing salts pre-sorbed on different brands of vermiculite also showed higher efficiency as a fire-extinguishing salt - ammonium phosphate.