FEATURES OF FIRE EXTINGUISHING BY FINELY DISPERSED GAS-AEROSOL SYSTEMS

It is shown that distinctive feature of aerosol, in comparison with powders and sprayed water, is especially high degree of dispersion of its particles. It is also shown that for extinguishing of emergency spills or fires in tanks it is necessary to ensure conditions of phlegmatization of combustible mixture of fuel vapors with air when expense of extinguishing aerosol is proportional to burning-out rate (evaporation) of liquid. Means of cooling of combustion products of aerosol-forming compounds (AFC) are considered. It is shown that the analysis of heat-mass exchange in combustion zone in case of aerosol extinguishing can be made in two ways. The analysis of material balance of fire extinguishing aerosol by analogy with early described analysis (in case of application of freons) is carried out. It is shown that modern AFC are the mix of polymeric binding agent with an inorganic oxidizer which type determine the technology and ways of obtaining of AFC charges. Such substances as potassium nitrate, potassium perchlorate and their mixtures are proposed as an inorganic oxidizer. It is established that usage of mixed oxidizer (ÊNÎ3 with ÊÑlÎ4) cause an effect of synergism. An example of negative impact of fire extinguishing aerosol on materials is given.