RESEARCH OF STABILITY AND EXPANSION OF COMPRESSION FOAM

Abstract

Introduction. Increasing the efficiency of extinguishing various types of fires is an urgent problem for firefighters-rescuers of Ukraine and the whole world. Every day, firefighters and rescuers use a variety of means to extinguish fires, save people, and eliminate the consequences of emergencies. However, modern realities require the improvement of these means. The war in Ukraine changed views on some firefighting and rescue strategies. That is why fire departments in Ukraine need modernisation of equipment, fire-technical equipment, as well as fire-extinguishing means. Special attention should be paid to the oil industry. Rockets hit oil tanks, as a result of which tanks are destroyed, oil products spill out in large quantities, and a large-scale fire can start. Fires in tanks with oil and oil products are among the most difficult to extinguish. They are characterised by huge material and environmental damage and are dangerous to human life and health [1]. We observed the consequences of such a situation on March 26, 2022, at the oil depot in Lviv on Plastova Street, where 30 tanks of various sizes and volumes are located. On this day, a missile attack was launched on the specified oil depot by the aggressor country, as a result of which several tanks were destroyed and oil products leaked with subsequent fire. The total area of the fire was more than 3000 m². The fire was extinguished after only 14 hours. Water and air-mechanical foam were used in large quantities as fire extinguishing agents. This case showed that it is necessary to introduce new fire extinguishing means or to look closely at those that have been actively used by foreign firefighters for some time. One of these means is systems for generating and supplying compression foam, which has already gained popularity in Europe and the USA. In Ukraine, such systems are not used by units of the State Emergency Service of Ukraine. Therefore, the development of fire extinguishing systems with compression foam and the technology of their application corresponds to the innovative directions of the development of the State Emergency Service of Ukraine [2]. A Compressed Air Foaming System (CAFS) is a system used in firefighting to deliver fire-resistant foam to extinguish fires or protect non-burning areas [3, 4]. Therefore, we conducted a study to determine the properties of the foaming agent and apply compression foam under the diesel fuel layer.
Purpose. The purpose of the work is to determine the effect of a liquid (water, gasoline, and diesel) on the destruction of foam during "sublayer" feeding and when feeding on the surface.
Methods. The work used the methods of analytical studies of the use of foam for extinguishing fires. Methods for determining indicators of foam quality, multiplicity and stability.
Results. In these studies, the compression foam showed high stability when interacting with diesel fuel and gasoline. Foam stability refers to its ability to maintain its structure over a certain period.
Conclusions. According to the research results, it can be concluded that the compression foam generated based on the Bars S-2 foaming agent showed good stability and multiplicity. During the interaction of compression foam with diesel fuel, we saw that the foam applied to the surface of the fuel remains on its surface without collapsing for a long time (14285 s when applied to a layer of diesel fuel and 2621 s when applied under the layer). When interacting with gasoline, the compression foam has a somewhat weaker effect (approximately 30 times less resistance when feeding on a layer of gasoline and 6 times less resistance when feeding under a layer) than when interacting with diesel fuel. These results show the possibility of using compression foam for "sub-layer" extinguishing. As of today, the fire and rescue units of Ukraine do not have appropriate domestic equipment for supplying compression foam, there are no methodological recommendations for the use of compression foam. The "underlayer" extinguishing method has not been studied in Ukraine and abroad, there are no relevant regulatory documents. To determine the efficiency of extinguishing with compression foam in fire conditions, it is necessary to conduct a study on extinguishing fires in tanks with petroleum products by the "underlayer" method and to determine the main fire-extinguishing properties of the foam.