SUPPRESSION OF THE THERMAL DECOMPOSITION REACTION OF FOREST COMBUSTIBLE MATERIALS IN LARGE-AREA FIRES

Experimental investigations on the characteristic time of suppression of the thermal decomposition reaction of typical forest combustible materials (aspen twigs, birch leaves, spruce needles, pine chips, and a mixture of these materials) and the volume of water required for this purpose have been performed for model fi re hotbeds of different areas: S_FCM = 0.0003–0.007 m² and S_FCM = 0.045–0.245 m² . In the experiments, aerosol water fl ows with droplets of size 0.01–0.25 mm were used for the spraying of model fi re hotbeds, and the density of spraying was 0.02 L/(m² ·s). It was established that the characteristics of suppression of a fi re by an aerosol water fl ow are mainly determined by the sizes of the droplets in this fl ow. Prognostic estimates of changes in the dispersivity of a droplet cloud, formed from large (as large as 0.5 L) "drops" (water agglomerates) thrown down from a height, have been made. It is shown that these changes can infl uence the conditions and characteristics of suppression of a forest fi re. Dependences, allowing one to forecast the characteristics of suppression of the thermal decomposition of forest combustible materials with the use of large water agglomerates thrown down from an aircraft and aerosol clouds formed from these agglomerates in the process of their movement to the earth, are presented
   
Author:  R. S. Volkov, A. O. Zhdanova, G. V. Kuznetsov, and P. A. Strizhak
Keywords:  forest combustible materials, thermal decomposition, hotbed of fi re, aerosol fl ow, water mass
Page:  411