Modeling combustion of micron-sized iron dust particles during flame propagation in a vertical duct

Abstract

In this study, an attempt has been made to investigate the fundamental aspects of premixed flame propagation in micro-iron dust particles. An analytical model of a one-dimensional dust flame is developed, with the particle combustion time modeled as a function of particle diameter. The flame structure is assumed to consist of two sections: preheat and combustion zone. By solving the energy equation in each zone and matching the temperature and heat flux at the interfacial boundaries, explicit algebraic equations for the laminar flame velocity and maximum flame temperature are obtained. The analysis allows for the investigation of the effects of particle size, and dust concentration on the combustion characteristics of iron dust clouds. This study explains that for micron-sized and larger iron particles the combustion time is proportional to d2. Besides, flame velocity can be correlated with the particle size according to a d−m relationship, with m=1. The calculated values of the combustion time and flame velocity show a reasonable compatibility with the experimental data.