PROSPECTS FOR THE USE OF FIRE-EXTINGUISHING AEROSOL BASED ON INORGANIC POTASSIUM SALTS FOR SCREENING OF THERMAL RADIATION IN FIRE

Abstract

Introduction. Based on the analysis of the number of fires of combustible liquids in tanks in the world, 50% of them are extinguished quickly, 25% go into prolonged, and 25% are not extinguished at all and are eliminated after the combustion of all combustible liquid. Because of this, the question of the effectiveness of not only extinguishing but also the spread of fire due to thermal radiation remains open. This issue becomes especially relevant when it is necessary toshield thermal radiation in the event of a fire in a hard-to-reach place, in particular, a limited volume of cable tunnel, the building of considerable height or depth, or inability to stay directly near personnel trunks due to chemical or radiation pollution, or other adverse conditions. The use of fire-extinguishing aerosol will effectively shield the surface from ther-mal radiation and limit the spread of fire due to the inability to heat combustible materials around the hearth.
The work aims to establish the possibility of using fire-extinguishing aerosol based on inorganic potassium salts to create shielding curtains as a way to protect objects from thermal radiation of significant capacity (more than 10 kW / m2) in fires.
Research methods. To achieve the goal and objectives of the study, theoretical research methods were used, which included analysis of fires, physicochemical characteristics of water curtains, generalization of the results of the study with their subsequent systematization to achieve the goal of the study.
The main results of the work. It is established that fire-extinguishing aerosol based on inorganic potassium salts can effectively absorb and shield thermal radiation while various processes take place - providing movement and mixing of fire-extinguishing aerosol, as well as processes that occur with the particles themselves - their decomposition and formation of additional gases - CO2, N2, H2O (steam), which are also able to actively absorb thermal radiation. It is determined that the fire-extinguishing aerosol can most effectively absorb infrared radiation because the size of the vast majority of aerosol particles is less than one μm.
Conclusions. The paper substantiates the use of fire-extinguishing aerosol based on inorganic potassium salts to absorb and create shielding curtains as a way to protect objects from the thermal radiation of significant capacity. It is substantiated that the fire-extinguishing aerosol can create stable (up to 40 min) curtains in time, which can effectively absorb powerful thermal radiation. It is theoretically substantiated that the scattering, reflection and absorption of heat flux at different frequencies are the main factors that provide shielding from the action of heat flux on fire.