2020-2_Pages_55-61

УДК  614.841.41                                                                               DOI 10.37657/vniipo.2020.99.2.006

A.V. Popov, A.V. Kazakov, D.V. Bukhtoyarov, D.V. Poltavets, S.Yu. Khatuntseva

EXTINGUISHING THE SMOLDERING COMBUSTION OF SAWDUST

Abstract. The analysis of existing theoretical and experimental studies on smoldering combustion of sawdust is carried out. There are considered the types of smoldering combustion. Practically, there is observed the implementation of three types of smoldering combustion. The first type is the process of oil-carbon sludge smoldering in the final phase of wood burning. The second type is smoldering combustion in dispersed, layered or fibrous carbon-containing materials. The third type of smoldering combustion is typical for carbonaceous materials that do not contain volatile components such as activated carbon. The method for determining the characteristics of seats of smoldering combustion is developed. Wood sawdust of coniferous species of different fractions was used for research. Experimental seats were cylindrical containers with a wall thickness of 1 mm: d = 66 mm, h = 100 mm; d = 72 mm, h = 80 mm; d = 54 mm, h = 100 mm; d = 65 mm, h = 115; d = 100 mm, h = 40 mm; d = 85 mm, h = 85 mm; d = 100 mm, h = 125 mm (d – diameter, h – height of the seat). Smoldering combustion model seat is experimentally proved. Based on the tests performed, a model seat with the height of 85 mm and the diameter of 85 mm was selected for further research (the criterion for seat selecting was the optimal degree of sawdust burnout), in which thermocouples were placed, according to Fig.1. There were used sawdust fractions of less than 0,1 mm, 0,1–0,2 mm, 0,2–0,4 mm and 0,4–1 mm. Sawdust moisture content w = 5 %. Tests were conducted to determine the rate of sawdust smoldering combustion and the maximum temperature of smoldering combustion. There is shown the change both of smoldering combustion rate and the sawdust mass depending on its dispersion. A laboratory method for determining the extinguishing effectiveness of sawdust smoldering combustion with various fire extinguishing agents was developed. The seat was placed into the conventionally sealed chamber of 1 m x 1 m x 1 m at the distance of 0,5 m from the walls. The chamber has lines for supplying bulk fire extinguishing agents, as well as devices for supplying fire extinguishing powders. There are obtained experimental results for extinguishing sawdust with gas fire extinguishing agents, dispersed water as well as with fire extinguishing powder

Keywords: combustion, smoldering, seat of smoldering, smoldering combustion of sawdust

References

1. Semenov N.N. O nekotoryh problemah himicheskoj kinetiki i reakcionnoj sposobnosti [On some problems of chemical kinetics and reactivity]. Moscow,АN USSR, 1958, 686 p. (In Russian).
2. Zeldovich Ya.B. Teorija gorenija i detonacii gazov [Theory of combustion and detonation of gases]. Мoscow, АN USSR, 1944, 71 p. (In Russian).
3. Frank-Kamenetsky D.A. Diffuzija i teploperedacha v himicheskoj kinetike [Diffusion and heat transfer in chemical kinetics]. Moscow, Nauka Publ., 1967, 491 p. (In Russian).
4. Khitrin L.N. Fizika gorenija i vzryva [Physics of combustion and explosion]. Мoscow, MGU Publ., 1957, 442 p. (In Russian).
5. Delmon B. Kinetika geterogennyh processov [Kinetics of heterogeneous processes]. Moscow, Mir Publ., 1972, 556 p. (In Russian).
6. Baratov A.N., Ivanov E.N, Korolchenko A.Ya. Pozharnaja bezopasnost'. Vzryvobezopasnost' [Fire safety. Explosion safety]. Moscow, Khimiya Publ., 1987, 272 p. (In Russian).
7. Abduragimov I.M., Androsov A.S. Processy gorenija [Combustion process]. Moscow, VIPTSH, 1984, 269 p. (In Russian).
8. Demidov P.G., Saushev V.S. Gorenie i svojstva gorjuchih veshhestv [Combustion and properties of combustible substances]. Moscow, VITSH МVD USSR, 1975, 279 p. (In Russian).
9. Drysdale D.D. Introduction to fire dynamics. Trans. from Eng. by K.G. Bomstein. Moscow, Stroizdat Publ., 1990, 424 p. (In Russian).
10. British Standards Institution. Method of test for the ignitability by smokers’ material of upholstered composites for seating. BS 5852 Part 1: 1979.
11. Ohlemiller T. Modeling of Smoldering Combustion Propagation, US Dep. Commer. Nat. Bur. Stand. Spec. Publ., № 639, 1982, pp. 266–307.
12. Drysdale D.D. Aspects of smoldering combustion – J. Fire Prevention Science and Technology, 1984, no. 23, pp. 18–23.
13. Van Krevelen D.W. Thermal stability of polymers. Polymer, 1975, vol. 16, no. 8, pp. 615–621.
14. Lavrov N.V., Shurygin A.P. Vvedenie v teoriju gorenija i gazifikacii topliva [Introduction to the theory of combustion and gasification of fuel]. Moscow, АN USSR, 1962, 216 p. (In Russian).
15. Lavrov N.V. Fiziko-himicheskie osnovy processa gorenija topliva [Physical and chemical bases of fuel combustion process]. Moscow, Nauka Publ., 1971, 88 p. (In Russian).
16. Rothbaum H.P. Spontaneos combustion of hay. J. Applied Chemistry, 1963, London, no. 13, pp. 291–302.
17. Trisvjatskij L.A., Mel'nik B.E. Tehnologija priema, obrabotki, hranenija zerna i zernoproduktov ego pererabotki [Technology of reception, processing, storage of grain and grain products of its processing]. Moscow, Kolos Publ., 1983, 361p. (In Russian).
18. Palmer К.N. Smoldering combustion of dusts and fibrous materials. Combustion and Flame, 1957, no.1, 129 p.
19. Thomas P.H., Bowes P.С. Section for some aspects of the self-heating and ignition of solid cellulose materials. Brit. J. Applied Chemistry, 1962, no. 13, 291 p .
20. Bowes P.C. Application of the theory of thermal explosion to the self-heating and ignition of organic materials. Fire Research Note. 1971, no. 867.

Received February 20, 2020

Authors:

Alexey V. Popov – Candidate of Technical Sciences, Leading Researcher. Е-mail:dvb01@bk.ru;

Alexey V. Kazakov – Candidate of Technical Sciences, Head of Department. E-mail: kav01@list.ru;

Dmitry V. Bukhtoyarov – Candidate of Technical Sciences, Deputy Head of Department. E-mail: dvb01@bk.ru;

Denis V. Poltavets – Senior Researcher. E-mail: poltavetsdenis@mail.ru;

Svetlana Yu. Khatuntseva – Senior Researcher. Е-mail: lu2986@yandex.ru.

All-Russian Research Institute for Fire Protection (VNIIPO), the Ministry of the Russian Federation for Civil Defense, Emergencies and Elimination of Consequences of Natural Disasters (EMERCOM of Russia), Balashikha, Moscow region, Russia.