Tactical possibilities of gas and smoke protection service units when extinguishing protracted fires at power facilities in the environment unsuitable for breathing

PURPOSE. The analysis of statistical data on fires at power facilities has shown that successful extinguishment of protracted fires in the environment unsuitable for breathing (UBE) requires continuous activities on the part of gas and smoke protection service units (GSPS). The duration of a firefighter’s stay in the UBE is determined by the time of the protective functioning of personal protective equipment for respiratory and vision organs. It is quite natural to conclude that it should exceed fire extinguishing time. The article considers the current method of operation of GSPS units at large and protracted fires, and also describes an experimental study to ensure the continuity of fire extinguishment by changing the units at the fire seat. The study was carried out in order to determine the number of GSPS units required to ensure the continuity of extinguishing developed fires at the premises of a large power facility at different depths of the combustion zone and the length of the UBE, which must be overcome to reach the positions of supplying fire extinguishing agents. The applicability of the developed self-contained set of continuous air supply to firefighters’ breathing apparatus has been studied, which can be used as the positions of fire extinguishing agents supply are determined. METHODS. The required number of GSPS units was experimentally determined to ensure the continuity of fire extinguishment at a certain distance of the fire seat from entering the UBE. The applicability of the developed autonomous set of continuous air supply was studied. FINDINGS. The results of the experimental study allow concluding that it is possible to ensure fire extinguishing continuity at a power object, provided the change of units takes place at the point of fire extinguishing agents charge, that is, at the fire seat. Thus interruptions in fire extinguishment, which occur when changing units takes place in the open air will be avoided. To cut expenses and reduce the number of people involved in extinguishing large fires, it is recommended to use two cylinders apparatus, since with a deep penetration of a unit into the UBE, one cylinder, as a rule, is enough for 5–10 minutes of effective extinguishment, while the rest of the time is used to overcome the way to the fire seat. RESEARCH APPLICATION FIELD. The findings of the study are planned to be used both in the educational process and in the practical activities of GSPS of the special fire departments protecting nuclear power plants and other power objects. Conclusions. The data obtained allow us to conclude that it is possible to ensure the continuity of fire extinguishment at a power facility in the following way: 1) by changing units at the place where fire extinguishing agents are supplied, that is, at the fire seat; 2) when using an autonomous set of continuous air supply to firefighters’ breathing apparatus. The set provides the GSPS unit with medium-pressure air and allows you to work in the UBE at the place of fire extinguishing agents supply for an unlimited time.