The accuracy and reliability of comparative efficiency assessment of portable fire extinguishers used in the process of fire extinguishing of structural components of motor vehicles and automotive finishing

Introduction. The relevance of this work resides in the need to perform an unbiased comparative assessment of fire extinguishers. The focus must be placed on the efficiency of a fire-fighting agent, as it has a major impact on the process of fire extinguishing. The purpose of this work is to confirm the applicability of a dimensionless efficiency indicator of portable fire extinguishers, assess the measurement accuracy (correctness and precision) and their statistical values.
Materials and methods. The co-authors used the methodology specified in GOST R 51057–2001 applicable to the fire extinguishing of class A model fire seats. The model fire seat had samples of materials attached to its upper edge at the angles whose values were obtained using a specialized test bed. A specialized test bed was used to perform the testing and identify the sample’s inclination angles that prevented the fire extinguishing agent, applied to their surface, from streaming down or crumbling. The accuracy (correctness and precision) was assessed pursuant to the methodologies specified in GOST R ISO 5725-1–2002, GOST R ISO 5725-6–2002. The statistical significance of measurements was assessed using Student’s t-test.
Results and discussion. The co-authors offer the results of the experiments aimed at the identification of an inclination angle of the fire seat surface that prevents the fire extinguishing agent from streaming down or crumbling. The results of comparative fire testing of fire extinguishers that contain quick setting foam and powder are provided. The formula of a dimensionless efficiency indicator, applicable to portable fire extinguishers, is provided, and its applicability is proven.
Conclusions. The measurement accuracy assessment, performed pursuant to the methodologies, specified in the regulations, has shown the effectiveness of mean arithmetic values of all indicators applied to calculate P_eo efficiency indicator. The assessment of the statistical significance of experimentally obtained values of all indicators, performed with the help of Student’s t-test, has demonstrated that the discrepancy of their mean arithmetic values is reliable and it doesn’t have a random nature. The superiority of the quick setting foam extinguisher over the powder one was proven in an experiment. The value of its P_eo efficiency indicator exceeds the one of a powder extinguisher 50-fold due to the comprehensive impact made by the extinguishing agent and the construction of a fire extinguisher.

1. Sobur’ S.V. Fire-extinguishers : handbook. 2nd edition. Moscow, Spectehnika Publ., 2003; 96. (rus).

2. Sobur’ S.V. Fire-extinguishers : learning manual. 11th edition. Moscow, PozhKniga Publ., 2018; 80. (rus).

3. Robin M.L., Anderson E.H. Portable fire extinguishers: Selection and distribution. International Fire Protection. 2004; 20:32-34.

4. Walker S. Portable extinguishers — training is the key to safe and effective use. International Fire Protection. 2008; 34:67-71.

5. Graham Collins. Portables, the first line of defense. International Fire Protection. 2011; 46:39-30.

6. Mark Bristow. Servicing fire extinguishers. International Fire Protection. 2019; 77:34-35.

7. Pivovarov V.V. Development of tactical and technical indicators and fire-extinguishers efficiency assessment : dissertation abstract ... candidate of technical sciences. Moscow, 1988; 22. (rus).

8. Sytdykov M.R. Efficiency assessment method for the powder fire-extinguisher with built-in porous container (applicable to fire dangerous production oil assets) : dissertation of the candidate of technical sciences. St. Petersburg, 2013; 115. (rus).

9. Kozhevin D.F. Method of the complex efficiency assessment of fire-extinguishers : dissertation of the candidate of technical sciences. St. Petersburg, 2011; 120. (rus).

10. Sorokin I.A., Polyakov A.S., Kozhevin D.F. Method for evaluating the effectiveness of powder fire extinguishers. Vestnik Sankt-Peterburgskogo Universiteta GPS MCHS Rossii. 2020; 2:16-23. (rus).

11. Abduragimov I.M., Govorov V.Yu., Makarov V.E. Physicochemical foundations of the development and extinguishing of fires. Moscow, VIPTSh Ministry of Internal Affairs of the USSR, 1980. (rus).

12. Vinogradov A.V., Kuprin D.S., Abduragimov I.M., Kuprin G.N., Serebriyakov E., Vinogradov V.V. Silica foams for fire prevention and firefighting. ACS Applied Materials & Interfaces. 2016; 8(1):294- 301. DOI: 10.1021/acsami.5b08653

13. Kuprin D.S. Physical-chemical explanation of fire-fighting efficiency of FHF (fast-hardening foam) based on structured silica particles. Journal of sol-gel science and technology. 2016; 81(1):36-41. DOI: 10.1007/s10971-016-4285-8.

14. Kuprin G.N., Kuprin D.S., Sergio Zubizarreta Cabanzon. Las modernas tecnologias de extincion de incendios de la Compania RSL USP “SOPOT”. “24/7”. Edicion No 4 Enero. 2018; 36-38.

15. Kuprin G.N., Kuprin D.S. Fast-hardening foam: Fire and explosion prevention at facilities with hazardous chemicals. Journal of Materials Science Research. 2017; 6(4):56-61. DOI: 10.5539/jmsr.v6n4p56

16. Kuprin D.S., Polyakos A.S. About efficiency of the handle fire-extinguishers for the automobile solid combustible materials fire-extinguishing. St. Petersburg, St. Petersburg State Fire University of Emercom of Russia Publ., 2020: 4; 32-39. (rus).

17. Korol’shenko A.Ya., Korol’shenko D.A. Fire and explosion danger of substances and materials and fire-extinguishing means for them : handbook. Part. 1. Moscow, Association “Pozhnauka”, 2004; 713. (rus).

18. Korol’shenko A.Ya., Korol’shenko D.A. Fire and explosion danger of substances and materials and fire-extinguishing means for them : handbook. Part. 2. Moscow, Association “Pozhnauka”, 2004; 7774. (rus).

19. Eliseeva I.I., Uzbashev M.M. General theory of statistics ; I.I. Eliseeva (ed.). 5th ed., refined and supplemented. Moscow, Finance and statistics Publ., 2004; 656. (rus).

20. Golicina O.M., Meremyanin A.V., Risin V.E. Mathematical processing of the measurements results in the lab practice of the general physics studying: Studying and methodical edition. Voronezh, VGU Publ., 2015; 20. (rus).