MAIN PARAMETERS OF EXTINGUISHING OF THE OIL FLAME BY LOW EXPANSION FOAM

Process of suppression of oil products by low expansion foam is investigated in this article. Time of flame suppression in a wide range of foam supply intensities is experimentally defined. Dependences of suppression time on foam supply intensity are formulated. Dependence of main extinguishing parameters — time of suppression and specific foam rate — in terms of suppression of a heptane flame by hydrocarbon (PO-3AI) and fluorine containing (Gidral, Petrofilm) foam agents is considered. It is shown that the nature of dependence of suppression time on foam supply intensity is caused by accumulation of foam on a burning liquid surface and its destruction under influence of a flame heat flow and contact with flammable liquid. The factors defining intensity of thermal destruction of foam are considered. The formula allowing to backtrace the foam losses speed changing by thermal destruction under the influence of a flame heat flow is obtained. It is concluded that intensity of foam destruction under the influence of a heat flow from combustion zone depends on degree of foam coating on a burning surface, type of foam agent, nature of flammable liquid. The comparison of calculated and experimental data on suppression time and specific foam rate depending on foam supply intensity is carried out.