DETERMINING THE EFFECT OF MODIFIED ADDITIVES ON THE FIRE-EXTINGUISHING PROPERTIES OF COMPRESSED AIR FOAM

Abstract

The object of this study is the fire extin-guishing efficiency of compressed air foam with the use of modified additives. The main hypothesis assumes that the use of modified additives in the composi-tion of the compressed air foam will affect its fire extinguishing efficiency when extin-guishing solid combustible materials.The task addressed is to determine the effect of modified additives in compressed air foam with a concentration range of 1–5% on its fire extinguishing properties. The results show that for all additives, when the concentration changes from 1% to5%, characteristic is a slight decrease in the consumption of an aqueous solution of the foaming agent. On the contrary, an increase in the expansion ratio results in a significant decrease in the mass of the aqueous solution of the foaming agent con-sumed for extinguishing. An increase in the concentration of the additive in the range of 1% to 3% is characterized by a decrease in the extinguishing time, while a further increase from 3% to 5% is characterized by an increase in the extinguishing time. Also, the increase in the foam expansion ratio has a significant effect; with an increase from 5 to 20, a decrease in the extinguish-ing time is observed, and with a further increase to 25, an increase in time occurs.For the compressed air foam with NH4H2PO4, the highest efficiency index is Ie.e≈20.15 m2/l∙s, at a modified additive con-centration of C≈3% and a foam expan-sion ratio of K≈18; for the compressed air foam with (NH4)2HPO4, the highest effi-ciency index is Ie.e=18.04 m2/l∙s, at a mod-ified additive concentration of C≈3% and a foam expansion ratio of K≈18; for a com-pression foam with (NH4)2CO3, the high-est efficiency index is Ie.e=14.99 m2/l∙s, at a modified additive concentration C≈3% and a foam expansion ratio of K≈18. Thus, based on the results of exper-imental studies, the most effective is the compressed air foam with NH4H2PO4. The resulting extinguishing efficiency is 11%higher than that of the compressed air foam with (NH4)2HPO4, and 26% high-er than that of the compressed air foam with(NH4)2CO3