EXPERIMENTAL STUDIES OF EXTINGUISHING GRASS FIRES BY AIR FLOWS AND AIR-WATER COMPOSITION

Abstract

Formulation of the problem. According to statistics, fires in natural ecosystems occur not only in Ukraine, but also in the world, and tend to grow annually. Along with the issues of preventing the occurrence of fires in natural ecosystems, it is important to study modern means and methods of their localization and elimination, especially at the initial stage of oc-currence.
The purpose of the work is to evaluate the expediency of using the Stihl SR 430 sprayer to extinguish a grass fire.
Description of the material. The research was based on a motorized sprayer Stihl SR 430, which was used to extin-guish a grass fire near Kyiv. The device was used both with the formation of airflow and with an air-water jet flow. The dependences of the speed of the airflow generated by such a device on the engine speed, distance from the nozzle and deviation from the direction of flow have been established. Results. Researchers have confirmed that in almost the entire range of distances (0,2−3 m), the airflow rate, as well as the air-water mixture at the average speed of the internal combustion engine of the equipment is less than at the maximum, which indicates the expediency of effective operation of the device precisely in medium speed mode. The best extinguishing results were obtained when using the airflow formed by the value of the average engine speed, which is directed into the fire centre in the horizontal plane at an angle of 0○. It has been established that the effectiveness of extinguishing a grass fire with air flows is achieved at a distance of 0.4−1 m from the nozzle to the combustion centre. The use of air-water flows ensures flame separation at a rate that is, on average, 1.24 times less than the value of this value for an airflow.