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

• Combustion characteristics of solid-state burning of iron particles were studied.
• Mass consumption rate and combustion time of micro-iron particles are calculated.
• Algebraic equations for flame velocity and maximum flame temperature are obtained.
• Combustion time grows quadratically, with a rise in particle diameters.
• Flame velocity follows the d−md−m law, with m=1m=1.

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 d2d2. Besides, flame velocity can be correlated with the particle size according to a d−md−m relationship, with mm=1. The calculated values of the combustion time and flame velocity show a reasonable compatibility with the experimental data.