Deflagration describes the subsonic combustion wave propagating through a premixed mixture of gaseous and/or particulate fuel and oxidizer. In dust deflagration dust particles are typically levitated in gas flows. Consequently, any deflagration event is closely coupled to the characteristics of the fluid-dynamical behaviour of dust particles. Dust deflagration poses a serious safety risk in any industrial process involving fine combustible dusts.
For the numerical analysis of deflagration of a typical volatile organic dust represented by maize starch, we employed a Euler-Lagrangian method, where the trajectories of the dust particles are tracked by representative parcels. Since the combustion of dust particles involves relatively high temperatures radiation is considered as well. Radiation is especially important during the initial phase of electric spark ignition for the energy transfer of spark energy to the surrounding particles. Furthermore, combustion of particles is considered a two-stage process. First, particles are heated by an ignition source (e.g., electric arc) triggering pyrolysis degassing mostly carbon monoxide and methane. The pyrolysis model was established via Thermogravimetry and gas analysis of a maize starch sample. Second, these pyrolysis gases combust in the gas-phase. Turbulent gas-phase combustion is modelled via the eddy dissipation model. Fuel conversion and a chemical timestep are modelled by a four-step mechanism proposed by Jones and Lindstedt [1].
Comparisons between predicted dust cloud evolution and flame speeds and experimental observations of deflagration events of organic dust in a vertical channel [2] reveal fairly good agreement. Finally, such numerical simulations enable the detailed investigation of deflagration events, which, in turn, allows the considerable improvement of process safety.

REFERENCES
[1] W. P. Jones and R. P. Lindstedt, “Global reaction schemes for hydrocarbon combustion,” Combust Flame, vol. 73, pp. 233–249, 1988.
[2] S. Puttinger et al., “Dust cloud evolution and flame propagation of organic dust deflagration under low wall influence,” J Loss Prev Process Ind, vol. 83, no. February, p. 105042, 2023, doi: 10.1016/j.jlp.2023.105042.