IMPROVING FIRE SAFETY OF METALIZED PYROTECHNICAL MIXTURES BY OPTIMIZING THEIR TECHNOLOGICAL PARAMETERS

Abstract

Purpose. The purpose of this work is to establish quantitative relationships between key technological parameters (fuel dispersion, oxidant excess coefficient) of metallized pyrotechnic mixtures and their fire safety indicators (ignition temperature, induction time, probability of activation) for scientific justification of measures to reduce risks during their operation.Problem statement and solution. Methods. Modern methods of physical and chemical analysis: thermocouple methods of temperature measurement (tungsten-rhenium thermocouples were used); non-contact methods of recording the beginning and end of the burning of metal particles (temperature indicators, photosensitive elements, etc); film shooting methods (film camera "Konvas-auto" (shooting speed 30 frames/s)) and methods of micro-filming SKS-1M film camera (shooting speed 3000...5000 frames/s)) of the burning process of individual metal particles; methods of X-ray structural and micro-X-ray spectral analysis for conducting chemical analysis. Results. The article presents a methodology for improving the fire safety of pyrotechnic products based on metallized mixtures with fluoroplastics. The main emphasis is placed on the influence of external thermal factors on key parameters, such as ignition temperature, induction time and probability of ignition source, as well as on the technical characteristics of the charges. The proposed method is aimed at optimizing the technological parameters of the mixtures, including the dispersion of the metal fuel, the excess oxidant coefficient, the compaction of the mixtures and the geometric features of the charges. The results of the research demonstrate that regulating the composition of pyrotechnic mixtures allows to significantly increase their resistance to ignition under the influence of external heat. Reducing the risk of fire and explosion-hazardous destruction is achieved through the use of finely dispersed metal powders, as well as replacing magnesium fuel with aluminum, which significantly improves the fire safety of the products. The application of the methodology allowed to increase the level of fire safety of pyrotechnic products both at the stage of their production and during transportation and storage. The results of the study create the basis for improving the regulatory framework and raising safety standards at Ukrainian enterprises. Scientific novelty. The first direction of the complex's work includes the development of mathematical models for calculating the processes of surface and volumetric transformation of matter. Thanks to these models, the modeling of physicochemical reactions that occur during heating or combustion of materials is carried out. This makes it possible to determine the main parameters - ignition temperatures, reaction rates, process stability limits and critical conditions under which the system may transition to a dangerous state. Practical significance. Thus, modification of the composition of pyrotechnic mixtures, in particular, changing the content of powdered metal fuels and their dispersion, allows to significantly increase the fire safety of products under the influence of external thermal factors – more than 1,4 – 2,3 times. In addition, replacing one metal fuel with another also contributes to increasing safety. For example, using aluminum powder instead of magnesium powder provides an increase in the fire safety of the product by 1,7 times. The developed method and database can be used as a basis for improving regulatory documents, implementing new safety standards and optimizing technological processes in the production, storage and transportation of pyrotechnic products in Ukraine. In the future, these results can be applied to the development of safe mixtures in other industries where ensuring the stability of chemical processes and minimizing the risks of ignition are important.