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Numerical simulation by the molecular collision theoryof two-phase mixture explosion characteristics in closedor vented vessels

Published online by Cambridge University Press:  15 September 1999

J. M. Pascaud
Affiliation:
Université d'Orléans, LEES, 63 avenue de Lattre de Tassigny, 18020 Bourges Cedex, France
J. Brossard
Affiliation:
Université d'Orléans, LEES, 63 avenue de Lattre de Tassigny, 18020 Bourges Cedex, France
J. M. Lombard
Affiliation:
GIAT Industries, 7 route de Guerry, 18023 Bourges Cedex, France
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Abstract

The aim of this work consists in presenting a simple modelling (the molecular collision theory), easily usable in an industrial environment in order to predict the evolution of thermodynamical characteristics of the combustion of two-phase mixtures in a closed or a vented vessel. Basic characteristics of the modelling have been developed for ignition and combustion of propulsive powders and adapted with appropriate parameters linked to simplified kinetics. A simple representation of the combustion phenomena based on energy transfers and the action of specific molecules is presented. The model is generalized to various mixtures such as dust suspensions, liquid fuel drops and hybrid mixtures composed of dust and a gaseous supply such as methane or propane in the general case of vented explosions.The pressure venting due to the vent breaking is calculated from thermodynamical characteristics given by the model and taking into account, the mass rate of discharge of the different products deduced from the standard orifice equations.The application conditions determine the fuel ratio of the used mixtures, the nature of the chemical kinetics and the calculation of a universal set of parameters.The model allows to study the influence of the fuel concentration and the supply of gaseous additives, the influence of the vessel volume (2400ℓ ≤ V b ≤ 250 000ℓ) and the influence of the venting pressure or the vent area. The first results have been compared with various experimental works available for two phase mixtures and indicate quite correct predictions.

Keywords

Type
Research Article
Copyright
© EDP Sciences, 1999

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References

Lee, J.H.S., Pu, Y.K., Knystautas, R., Archiv. Combust. 7, 279 (1987).
R. Klemens, P. Wolanski, Flame structure in dusted-air and hybrid-air mixtures, 10th ICDERS, Berkeley, 1985.
Pascaud, J.M., Brossard, J., Combust. Sci. Tech. 113-114, 613 (1996). CrossRef
J.P. Pineau, J. Chaineaux, G. Ronchail, Influence on gas and dust explosion development of lengthening and presence of obstacles in closed or vented vessels, 5th Int. Symp. Loss Prevention and Safety Promotion in the Process Industries, Cannes, 1986.
J.M. Lombard, R. Bouigue, Application of molecular collision theory to gas-solid reactions: ignition and combustion of pyrotechnic compositions, 9th Int. Pyrotechnics Seminar, Colorado Springs, 1984.
Y. Rocard, Thermodynamique (Masson, Paris, 1967).
Bradley, D., Mitcheson, A., Combust. Flame 32, 221 (1978). CrossRef
K.N. Palmer, Z.W. Rogowski, Fire Research Station, Fire Research Note N°613, Boreham Wood 1966.
C. Yao, 8th Loss Prevention Symp., Antwerp, 1974, p. 1.
J.M. Pascaud, J. Brossard, J.M. Lombard, Practical modelling of dust explosions, 14th ICDERS, Coimbra, 1993.
W. Bartknecht, Pressure venting of dust explosions in large vessels, 5th Int. Symp. Loss Prevention and Safety Promotion in the Process Industries, Cannes, 1986.
W. Bartknecht, Explosionen, Ablauf und Schutzmassnahmen (Springer-Verlag, Berlin, 1978).
Lemos, L., Bouriannes, R., Progr. Astron. Aeron. 132, 13 (1991).
J. Nagy, H. Verakis, Development and Control of Dust Explosions (Marcel Dekker INC, New York, 1983).
Tai, C., Kauffmann, C., Sichel, M., Nicholls, J., AIAA Progr. Astron. Aeron. 113, 62 (1988).
Pu, Y.K., AIAA Progr. Astron. Aeron. 113, 3 (1988).
R. Enright, Experimental evaluation of the 1, 2, 8 and 20 liters explosion chambers, 1st Int. Col. on Explosibility of Industrial Dusts, Baranow, 1984.
F. Bond, M. Fresko, R. Knystautas, J.H.S. Lee, Influence of turbulence on dust explosion, 1st Int. Col. on Explosibility of Industrial Dusts, Baranow, 1984.
W. Leuckel, W. Nastoll, N. Zarzalis, Experimental investigation of the influence of turbulence on the transient premixed flame propagation inside closed vessels, 23rd Int. Symp. on Combustion, Orléans, 1990.
Veyssière, B., Proust, C., Combust. Sci. Tech. 62, 149 (1988).
D.M. Solberg, J.A. Pappas, E. Skramstad, Observations of flame instabilities in large scale vented gas explosions, 18th Int. Symp. on Combustion, Waterloo, 1980.