INTERACTION OF TYPICAL FIRE-EXTINGUISHING LIQUIDS WITH THE FOREST FUEL COMBUSTION FRONT

The paper presents the results obtained in experimental studies of the processes of localizing the combustion of typical forest fuel materials (needles, foliage, and their mixtures with twigs) using a control line (fi rebreak) of a wetted layer of such materials formed before the fronts of their thermal decomposition and combustion. Water, bischofi te solution, OS–5 solution, bentonite suspension and a foaming agent emulsion were used as fi re-extinguishing agents. Relative mass and volume concentrations of water impurities were selected in accordance with ranges that are typical of modern fi re-extinguishing systems. The possibility is shown for localizing the combustion of the said materials by reducing their temperature through heat accumulation by water, which has a high heat capacity and undergoes endothermic phase transformations, and blocking the access for the oxidizer and pyrolysis products to the fl ame combustion zone by forming a buffer zone from relatively cold water vapors and reducing the concentration of the products of materials' thermal decomposition as a result of the fi re-extinguishing agent spreading on their surface and pores. The conditions are determined for guaranteed localization of the burning of a forest area by supplying its control line with a liquid composition in the form of a massive water drop, a jet and aerosol. It is shown that the supply of an aerosol cloud to the control line is the most effi cient method in terms of minimal liquid consumption and guaranteed combustion localization
   
Author:  G. V. Kuznetsov, K. O. Ponomarev, A. V. Zakharevich, and P. A. Strizhak
Keywords:  forest fuel materials, pyrolysis, combustion, control line, fi re-extinguishing agent, emulsion, solution, suspension
Page:  1395