Experimental Observations of the Aluminium Combustion Process During Flame Propagation in a Tube

Combustion process during metallic dust flame propagation is still a point of discussion. Heterogeneous combustion (between solid particles and the air) or partial heterogeneous combustion followed by homogeneous combustion (in the gas phase) are two possible metallic combustion processes. In this work, aluminium flame propagation inside a tube is studied. Some experimental observations of this flame propagation mechanism are presented: as for example, micro-explosions of particles, white tail-like light following particles... These different observations seem to agree with a (partial) homogeneous combustion process in the gas phase

TRAITEMENT D'AIR CHARGE EN COV HYDROPHOBES PAR UN PROCEDE HYBRIDE : ABSORPTION – PERVAPORATION

Volatile organic compounds (VOC) entail nuisances for humans and the natural environment. Increasing strict rules force the industrials to set up equipments of air treatment ofr their VOC charged effluents. This work studies the technical feasibility of an innovative hybrid process among the at present available techniques: the coupling of an absorption process and a membrane separation, pervaporation. The various aspects of this process are examined: choice of the absorbent, study of hydrodynamics and mass transfer in a packed column, separation of pollutants contained in the absorbent by pervaporation, coupling of the two processes. At the end, an analysis of the process underlines main parameters and their impact on the coupling efficiency. It is shown that hybrid process turns out feasible.Les composés organiques volatils (COV) sont source de nuisances pour l'Homme et le milieu naturel. Des réglementations de plus en plus strictes imposent d'équiper les unités industrielles d'un procédé de traitement des effluents gazeux chargés en COV lorsque cela est nécessaire. Ce travail étudie la faisabilité technique d'un procédé hybride innovant parmi les techniques actuellement disponibles : le couplage d'un procédé d'absorption et un procédé membranaire, la pervaporation. Les différents aspects de ce procédé sont examinés : choix de l'absorbant, étude de l'hydrodynamique et du transfert de matière en colonne garnie, séparation des polluants contenus dans l'absorbant par pervaporation, couplage des deux procédés. Au final, une analyse du procédé met en lumière les grandeurs influentes et leur impact sur l'efficacité du couplage. Il est montré que le procédé hybride s'avère faisable techniquement

CFD study of the behavior of LPG tanks exposed to forest fires

Forest fires represent a growing safety concern since their frequency is increasing, with severe damages to humans, environment and structures. The present work focuses on the impact of forest fires on a particular type of target: liquefied petroleum gas (LPG) tanks. A computational fluid dynamic (CFD) model was applied to simulate the response of LPG tanks of different sizes exposed to a forest fire scenario. Results are presented in terms of pressurization rates, temperature distributions and velocity fields focusing on the effects of the tank size variation on the vessel response. In particular, it is pointed out how the tank diameter greatly affects the pressurization rate, but it as a negligible effect on the wall temperature distribution. The outcomes of this work provide useful results to evaluate the possible failure conditions, thus supporting the emergency response to wildland fires