Experimental research of sub-layer feed of self-foaming gas-aerosol filled foam for extinguishing fires in tanks with oil products
In Russia a significant number of tanks are equipped with sub-layer fire extinguishing systems. Foam lines are used to feed the foam into the tank, and various foam generators are used to produce it. The article presents information on the problems of extinguishing fires in tanks using the classical technology of sub-layer fire extinguishing. The relevance of research on the use of a pulsed fire extinguishing method with a sub-layer feed of self-foaming gas-aerosol-filled foam is shown. For practical confirmation of the effectiveness of SGP “subsurface” way at the site of the Orenburg branch of FGBU VNIIPO EMERCOM of Russia there was carried out in-situ prior (without fuel load) and fire tests on the tank RVS-5000. In the preliminary test, the SGP feed was carried out from the «Uragan-7,5-200-300» and it was experimentally confirmed that it is possible to obtain a SGP when it is fed through a layer of water. The results of preliminary tests to study the ascent of the SGP through the liquid layer are presented: the time of ascent, the time of covering the mirror area, the multiplicity, and the loss of the SGP in the dry tube. Fire tests were carried out to determine the possibility of extinguishing AI-95 gasoline on the RVS-5000 mirror by sub-layer feeding of the SGP and the possibility of feeding the SGP through an extended dry pipe. When conducting fire tests, two UPAT-7500-M units were used to feed the SGP. Tests have shown high efficiency of extinguishing oil products with pulsed fire extinguishing method with the SGP supply, including long dry pipes. A set of factors that ensure high efficiency of the investigated method of fire extinguishing is presented. At present, an important issue is the adaptation of the SGP feed technology to the existing infrastructure of sub-layer fire extinguishing. This will make it possible to use this highly effective technology on existing tanks equipped with sub-layer fire extinguishing systems and increase the level of fire protection of tank farms.