A device for creating a water-film protective screen against the thermal radiation of a fire
Authors:   Voronezh State University of Engineering Technologies, Maltsev Maxim Valerievich 
Published: December 2023

Introduction. A device for creating a water-film protective screen designed to protect the fireman in case of fire by significantly reducing the density of the radiant heat flux was studied by the author in this work. The proposed device, unlike analogues, does not have additional metal structures, for example, shields, while being able to create a stable liquid shield necessary to protect the fireman from the thermal radiation of a fire. By mathematical transformations, dependences are obtained for determining the thickness of the water film screen and the required value of the internal overpressure of the liquid in the device. In the course of mathematical transformations, an expression is obtained for determining the fluid pressure required for the expiration of a stable liquid film of a given thickness. Purposes and tasks. To learn how the device works. To create an experimental device to study the process of a water-film screen forming. To develop a methodology of experiments. To carry out an experiment to determine the device operating modes, depending on the fluid flow parameters. To determine experimentally the maximum value of the diameter of a continuous and stable water-film screen. To get a mathematical relationship to determine the thickness of the water-film protective screen and the value of the required overpressure of the liquid inside the device to obtain a continuous and stable screen. Methods. Natural experiment. Observation. Measurement. Description. Finding dependencies based on mathematical processing of experimental data. Results and discussion. A natural experiment was conducted. The results of research on the creation of a water-film protective screen have been obtained. The most optimal parameters of the device operation have been determined. It is established that the value of the diameter of the water film screen is 10 times greater than the value of the diameter of the channel of the device for the outflow of liquid. The use of known means of protection against the effects of radiant heat exposure contributes to a significant reduction in the distance from the point of use of fire extinguishing means to the point of fire occurrence. However, the devices used are made of heat-conducting materials, which makes it difficult to operate them as a means of protection against radiation from a thermal source of ignition at a small distance between them. In addition, the presence of metal structures reduces the possibility of using these devices when using additional fire extinguishing means. The basis for the regular operation of the proposed device for the formation and issuance of a protective liquid screen for fireman is to create a film curtain of liquid, the thickness and diameter of which is determined and regulated by the hydrodynamic operating mode and design characteristics. Conclusions. The proposed device works without additional metal structures (shields and nets), which makes it possible to use it at facilities with difficult access to an ignition source. Keywords: fire; thermal radiation; water curtain; water film; protective screen.