Study of the Efficiency and Transparency of Fire Extinguishing Aerosols


Annotation:

Fire-extinguishing aerosol particles efficiently suppress the flame combustion but worsen evacuation conditions due to a decrease in the atmospheric transparency. After deposition, the particles create a corrosive environment. In addition, solid particles negatively affect the operation of devices moving parts and mechanisms. Removal of aerosol particles from the object is significantly difficult, especially from the closed cavities of devices, computers, etc.
Known studies contain sufficiently detailed information about the fire-extinguishing ability of various formulations of an aerosol-forming composition considering the conditions for their use. Less attention is paid to the transparency study of gas media with micron-sized particles both in our country and abroad.
At the same time, the study of fire extinguishing ability in relation to the transparency of the aerosol is extremely rare. Therefore, a study aimed at finding the mutual dependence of the aerosol-forming composition on the aerosol transparency is an urgent task.
The article proposes a calculated dependence for calculating the transparency index of a medium with an aerosol on the concentration and average diameter of the particles, while noting the convergence of the results of calculation and experiment. All the experimental data on the transparency of fire-extinguishing aerosol correlate with the known data on the dispersion of aerosol particles, which were obtained by the laser diffraction method. In this case, the dispersion assessment was carried out in a fairly simple way without use of the sophisticated equipment.
The medium transparency index and the fire-extinguishing ability of the aerosol are considered in interrelation. A series of experimental data was processed for the number of compounds of the aerosol-forming composition. As a result of data generalization, the dependence of the aerosol-forming compounds minimum extinguishing ability on the aerosol transparency in the range from zero to 100 % was obtained. It is shown that the use of aerosol filtration allows to increase the medium transparency to 50 % or more due to reducing the concentration of particles and increasing their size.
For all the compounds, the mass of the aerosol-forming composition increases, the combustion of which leads to an efficient fire extinguishing and more transparent aerosol. 
The application of the obtained results allows to reduce the volume of fire experiments in the development of new efficient and safe aerosol-forming compositions for fire extinguishing, as well as in the study of the transparency of media with aerosol.

References:
1. Agafonov V.V., Kopylov N.P. Aerosol fire-extinguishing installations. Main characteristics: study guide. Мoscow: VNIIPO, 2001. 91 p. (In Russ.).
2. Korolchenko D.A., Sharovarnikov A.F. Features of fire extinguishing by finely dispersed gas-aerosol systems. Pozharovzryvobezopasnost = Fire and Explosion Safety. 2014. Vol. 23. № 10. pp. 67–72. (In Russ.).
3. Bobkov S.A., Baburin A.V., Komrakov P.V. Physical and chemical bases for the development and extinguishing of fires: textbook. Мoscow: Akademiya GPS MChS Rossii, 2014. 210 p. (In Russ.).
4. Agafonov V.V., Grishakina V.A., Kopylov S.N. Improved visibility in an aerosol environment. Pozharnaya bezopasnost = Fire Safety. 2010. № 1. pp. 97–101. (In Russ.).
5. Agafonov V.V., Golubchikov A.V., Zhivotkov A.V. Improving the safety of solid fuel generators of the fire- extinguishing aerosol. Pozharnaya bezopasnost = Fire Safety. 2013. № 3. pp. 47–51. (In Russ.).
6. Fu Y.H., Kuznetsov A.I., Miroshnichenko A.E., Yu Y.F., Luk’yanchuk B. Directional visible light scattering by silicon nanoparticles. Nature Communications. 2013. Vol. 4. DOI: 10.1038/ncomms2538
7. ISO 15779:2011. Condensed aerosol fire extinguishing systems — Requirements and test methods for components and system design, installation and maintenance — General requirements. Available at: https://www.iso.org/standard/52016.html (accessed: January 10, 2023). 
8. GOST R 53284—2009. Fire engineering. Generators of extinguishing aerosol. General technical requirements. Test methods. Available at: https://docs.cntd.ru/document/1200071930 (accessed: January 10, 2023). (In Russ.).
9. Friedlander S.K., Marlow W.H. Smoke, Dust, and Haze: Fundamentals of Aerosol Behavior// Physics Today. 1977. Vol. 30. Iss. 9. DOI: 10.1063/1.3037714
10. Rawle A.F. Basic Principles of Particle Size Analysis. Surface Coatings International Part A: Coatings Journal. 2003. Vol. 86. Iss. 2. pp. 58–65.
11. Hahn D.W. Light Scattering Theory. Available at: https://pdfslide.net/documents/hahn-light-scattering-theory.html?page=1 (accessed: January 10, 2023).
12. Mishchenko M.I., Travis L.D., Lacis A.F. Scattering, Absorption, and Emission of Light by Small Particles. Available at: https://www.giss.nasa.gov/staff/mmishchenko/publications/book_2.pdf (accessed: January 10, 2023).
13. ISO 13320:2009. Particle size analysis — Laser diffraction methods. Available at: https://www.iso.org/standard/44929.html (accessed: January 10, 2023). 
14. Mednikov E.P. Turbulent transport and deposition of aerosols. Moscow: Nauka, 1981. 176 p. (In Russ.).
DOI: 10.24000/0409-2961-2023-2-21-27
Year: 2023
Issue num: February
Keywords : methodology calculation experiment aerosol концентрация dispersion modelled fire seat particles transparency fire-extinguishing ability
Authors:
  • Smirnov N.V.
    Smirnov N.V.
    Cand. Sci. (Eng.), Lead Researcher, vniipo22@mail.ru FGBU VNIIPO EMERCOM of Russia, Balashikha, Russia
  • Kazakov A.V.
    Kazakov A.V.
    Cand. Sci. (Eng.), Department Head All-Russian Research Institute of Fire Protection of the EMERCOM of Russia, Balashikha, Russia
  • Agafonov V.V.
    Agafonov V.V.
    Dr. Sci. (Eng.), Chief Researcher FGBU VNIIPO EMERCOM of Russia, Balashikha, Russia
  • Kopylov N.P.
    Kopylov N.P.
    Dr. Sci. (Eng.), Prof., Chief Research Associate, np.nanpb@mail.ru FGBU VNIIPO of EMERCOM of Russia, Balashikha, Russia