JUSITFICATION OF DRY CHEMICAL POWDERS TESTING PROCEDURE

Abstract

The analysis of the problem of extinguishing fires of magnesium and its alloys is carried out. The urgency of studying the problem is confirmed by the fact that during the extinguishing of class D fires there are factors that can complicate the quenching process. Often, these metals actively react with water, which leads to an even greater spread of the fire and even an explosion. Therefore, special fire extinguishers, which have passed the proper test, are more effective in locating the fire and prevent the burning of the powder to form the "tongues" of the flame. In Ukraine, there is no method for testing the effectiveness of fire extinguishants of special purpose for the extinguishing of class D fires. The normative documents have been analyzed, which specify the procedures for testing extinguishing fire-extinguishing special-purpose fire extinguishing class D. Specifically: the methods are described in the international standard ISO 7165: 2017 «Fire fighting – Portable fire extinguishers – Performance and construction» and GOST 53280.5-2009 Fire fighting systems automatic. Extinguishing agents. Both methods have a number of shortcomings that need to be addressed when creating a Ukrainian fire test method for extinguishing fire extinguishing class D, namely: the dimensions of the metal frame made of sheet steel with a side (500 ± 10) mm, height (150 ± 5) mm for testing with magnesium chips are small; Not specified quantity of gasoline necessary for the rise of magnesium; The gas or oxygen torch used to dissolve magnesium does not provide full-value combustion throughout the area, but only creates separate cells of ignition. A draft methodology has been developed that determines the fire-extinguishing efficiency of powdered powders used in Ukraine. The required amount of fuel for burning magnesium and its alloys is determined. It was ascertained that for the firing of magnesium chips it is necessary to use at least 127 grams of gasoline of the mark A 92. Key words: test method, fire extinguishers of special purpose, extinguishing of fires of magnesium alloys