ENHANCEMENT OF HIGH-EXPANSION FOAM GENERATOR FOR FIRE SUPPRESSION IN TUNNEL-TYPE CABLE STRUCTURES

Abstract

This article presents the improvement of high-expansion foam generators for fire suppression in cable structures. The use of foam generators by the State Emergency Service of Ukraine during fires is a common practice and involves standard procedures for firefighting. However, there is a particular challenge when using generators in terms of their weight and geometric dimensions, which can limit the mobility of personnel in relatively confined spaces such as cable tunnels and tunnel structures. Therefore, greater attention should be given to the use of high-expansion foam generators. In cases where stationary foam fire suppression systems are absent or malfunctioning in cable structures, firefighting units of the State Emergency Service of Ukraine rely on firefighting equipment. Under these conditions, medium and high-expansion air-mechanical foam, obtained using foam generators such as HPS-type and foam-generating installations based on PD-7 and PD-30 smoke exhausters, are utilized for fire suppression. Foam isolates the burning zone from combustible vapors and gases, as well as the combustible surface of materials from the radiated heat of the reaction zone. It effectively penetrates into enclosed spaces, overcomes turns and inclines, rapidly fills the volume of the area, and displaces high-temperature combustion products, thereby reducing the temperature inside the enclosure. Existing medium and high-expansion air-mechanical foam generators are known to include a housing with a mesh package, an air supply device, and a spray nozzle. The mesh package is cone-shaped with its apex facing the flow of foam-generating solution, and the suction part is equipped with a louver grille with rotating plates. However, these generators have large dimensions and significant weight, which complicates the movement of rescue personnel. Considering the aforementioned factors, the primary task for successful fire suppression is the arrival time of the firefighting unit and the deployment and delivery time of the first hose stream. Therefore, it is necessary to make the generator convenient for transportation and use. This task is addressed through the development of a portable high-expansion foam generator, consisting of a housing, mesh package, spray nozzle, air supply device, and an elastic hose made of woven materials. This generator not only offers convenience in utilization but also reduces the time required to introduce the first hose stream for fire suppression, thereby minimizing casualties and material losses resulting from fires.