Composition for cooling of pyrotechnically generated hot aerosols

Abstract. Technology based on condensed aerosol has become increasingly popular as a Halon substitute for fire safety application in enclosed spaces. Aerosol forming composite (AFC), a pyrotechnic based component of condensed aerosol based fire extinguishing system (CAFES), burns to produce hot aerosols [1]. Aerosols that are produced must be cooled to prevent the possibility of secondary fires. The temperature of hot aerosol was recorded a maximum of 1200°C [2]. Therefore, cooling pellet composite (CPC) tablets must be positioned after AFC in order to absorb heat of hot aerosols. The integration of cooling pellet composite tablets into a CAFES system significantly enhances its heat management capabilities. The use of cooling tablets in CAFES systems is supported by several aspects, which contribute to enhanced thermal control. The cooling tablets possess the ability to reduce the temperature of a hot aerosol, either through the process of endothermic decomposition or by a phase change of ingredient of cooling composite.The cooling tablets also possess the capacity to decrease the concentration of harmful gases released during the combustion of aerosol-forming composites. MnCO3, basic MgCO3 based CPC were developed. By progressively incorporating magnesium carbonate, a range of compositions were generated, and their thermal properties were evaluated by means of TGA-DTA. At a MnCO3 to MgCO3 ratio of 35:50, the highest endothermic behavior was observed, with a ΔH value of 550 J/g. The binder ratio was also subsequently optimized. Using the UTM machine, the compressive strength of the tablets was determined. Compressive strength of 93 MPa was attained through the best combination of hot PVA and sodium silicate in the proportions of 4:2.Thermal clarance study was also performed to determine the best ratio of AFC:CPC. By employing these cooling tablets in CAFES of 0.1 kg AFC capacity, the temperature of the hot aerosol reduced from 1209 to 448°C.