Flame propagation of combustible dusts: A Mallard-Le Chatelier inspired model

In this work, a three-layers Mallard-Le Chatelier inspired theoretical model is developed to fully characterise the steps occurring during the flame propagation of combustible dusts/air. The model is based on the hypothesis that the dust flame propagation follows a homogeneous path: the dust-air mixture is pre-heated up to the volatile point ( VP ), at which production of volatiles occurs, thanks to the backdiffusion of heat from the combustion zone of the flame to the colder zones. The volatiles produced are then heated up to the ignition temperature and enter in the combustion zone. The flame burning velocity is the results of the coupling between heating rate, pyrolysis and/or evaporation/sublimation rate and volatiles combustion rate. The rate of formation of volatiles was measured by means of TG/DSC analysis. The laminar burning velocity of gases was computed by simulating the gas flame propagation in a tube starting from the measured gas compositions (by literature data or FTIR analysis). (c) 2023 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

In this study, a three-layers theoretical model inspired by Mallard-Le Chatelier is developed to comprehensively describe the steps of flame propagation in combustible dusts/air. The model assumes that the dust flame propagation follows a homogeneous path, where the dust-air mixture is pre-heated until volatiles are produced, and these volatiles enter the combustion zone after being heated to the ignition temperature. The flame burning velocity is determined by the coupling between heating rate, pyrolysis and/or evaporation/sublimation rate, and volatiles combustion rate. The formation rate of volatiles is measured using TG/DSC analysis, and the laminar burning velocity of gases is computed by simulating gas flame propagation in a tube based on measured gas compositions.