INVESTIGATION OF THE POSSIBILITY OF OBTAINING BIODEGRADABLE FOAMS FOR FIRE EXTINGUISHING BASED ON LOCAL RAW MATERIALS

Abstract

Приведены результаты исследований по получению пенообразующего вещества из корней растений. Дана характеристика огнетушащих свойств пены. Указаны способы определения эффективности огнетушащих пен с помощью комплекса физико-химических показателей. Показаны пути повышения эффективности тушения пожаров с помощью пены. Проанализированы литературные данные, касающиеся получения наиболее перспективных синтетических пенообразователей на основе алкилсульфатов, алкилсульфанатов и других анионактивных соединений, а также галогенсодержащих поверхностно-активных веществ. Рассмотрены недостатки синтетических пенообразователей. Foams which are colloidal systems of gas bubbles surrounded by liquid films are more advanced and widely used extinguishing agents. The extinguishing effect of foam is primarily an insulating effect, but also the cooling of the hot surface by the water contained in the foam. The use of foams offers the following advantages: significant reduction of water, the ability to spread over the burning surface and, therefore, the possibility of covering the burning surface when foam is applied in one place (in case of extinguishing with water it is necessary to irrigate the entire burning surface), as well as increased wetting power compared to water. Foams are used for extinguishing fires of solid and liquid substances that do not interact with water, and primarily for oil products. The proposed foams are widely used in extinguishing fires of tanks with flammable liquids, as well as in emergency landing of aircraft, in technological proceduces of manufacture. To increase the efficiency of fire extinguishing it is necessary to introduce additives reducing the surface tension of water. Some natural (protein-containing) and synthetic surfactants are used as such additives, called foaming agents (FA). Besides, stabilising additives are also introduced into them in order to increase the stability of foams. The physico-chemical and fire-extinguishing properties of foams are considered in sufficient details in research works. One of the most important directions in further increase of efficiency of foam fire extinguishing is to find new foaming agents providing increased stability of foam on the surface of burning material, good spreadability of foam, etc. at low consumption of foaming agent. A lot of systematic work is being done in this direction in advanced industrial countries. The analysis of patent literature shows that the most promising are synthetic blowing agents based on alkyl sulphates, alkyl sulphonates and other anionactive compounds, as well as halogen-containing surfactants. The disadvantages of using the above-mentioned substances are that, firstly, they are subjected to weak biological oxidation, which leads to environmental pollution, and secondly, to obtain these substances synthetically requires large material costs. Therefore, the authors used a natural material, the root of the plant to produce foam. The structure of the obtained substance was studied by mass spectroscopy. Foaming property of the substances was studied according to State Standard GOST 50588-2012. Thus, it is possible to obtain an economically favourable, environmentally friendly, stable foaming agent from local raw materials, e.g. from the roots of Allochrusa gypsophiloides, widely spread on the territory of the Republic of Uzbekistan.