Experimental study on the effect of dry water materials on the fire extinguishing efficiency and suppression mechanism of wood crib fire

Abstract

Micron‐sized dry water particles assembled from gaseous silica and deionized water were prepared by physical dispersion method, and the effects of two chemical components on the microstructure and fire extinguishing efficiency of dry water materials were analyzed. Three different filling pressures were selected to study their effect on dry water extinguishing efficiency of wood crib fire. The effect of dry water on fire extinguishing efficiency of wood crib was studied by building wood crib of different sizes. The results show that the larger filling pressure inhibits the fire more obviously, but the dry water structure is easy to be damaged. Dry water can adhere to the inside of the wood crib structure and exert its role of cooling and isolating oxygen to inhibit its smoldering under a certain release pressure. With the increase of the size of wood crib, the suppression efficiency of dry water materials on wood crib fire gradually decreases with increasing extinguishing time. The fire extinguishing efficiency of dry water with sodium acetate is improved, but its structure is not stable. By comparing and analyzing the critical combustion rate and oxygen concentration of wood crib, it was found that continuous cooling to reduce the combustion rate and smoldering is the dominant mechanism of dry water on wood crib fire.