Resolved simulations of single iron particle combustion and the release of nano-particles

Numerical modeling of pulverized iron flames in a multidimensional hot counterflow burner

“…The combustion enthalpy is scaled to ensure the calculated stoichiometric flame temperature agrees with the experimental observation. In fact, this treatment is consistent with that in previous works for iron combustion with the same scaling factor being adopted [5,27] . The parameter s is the stoichiometric ratio, which relates the mass change of fresh iron to that of burning parti- is the reference temperature, and δH re f c,k the formation enthalpy of species k at the reference temperature T re f .…”

“…In accordance with previous modeling approaches [3,5,27] , the iron oxide surrounding the iron core is assumed to be porous such that the oxygen can diffuse towards the unreacted iron surface without impediments. Based on this assumption, the reactive and diffusive particle surfaces are equal and can be calculated as,…”

In-flight iron ore reduction and nanoparticle formation in an atmospheric pressure hydrogen microwave plasma

“…Considering the high gas temperature, the rapid reduction observed in this work can be explained by the melting and evaporation of the particles in the plasma. Models of particle heating under similar conditions [44] imply that particles (size ∼10 µm) passing through the active plasma region should be expected to reach the melting (1870 K) temperature of magnetite within a few ms. Further, Thijs et al [45] showed that significant evaporation of iron/iron oxide particles (size ∼40 µm) occurs within tens of milliseconds at particle temperatures of 2400 K. In this context, it is now possible to identify the three types of particles observed after the plasma treatment in figure 2(c) as: (i) Nanoparticles created from the iron vapor caused by the partial/complete evaporation of the feedstock. (ii) Particles and smaller agglomerates that melted and fused but were not (completely) evaporated.…”

Effect of Fe–O ReaxFF on Liquid Iron Oxide Properties Derived from Reactive Molecular Dynamics

“…To design and improve real-world iron-fuel burners, an in-depth understanding of the fundamentals underlying the combustion of single iron particles is required. In the past few years, the number of more detailed experimental − and theoretical studies − regarding the combustion of single iron particles has increased drastically. In this early research on iron particle combustion, a good agreement between experiments and theoretical models for low gas temperature (300 K) and low oxygen concentration cases (up to X O2 = 0.21) was obtained.…”

“…Figure15. Effect of different ReaxFF parameter sets and hypothetical particle morphologies on the temperature vs time curve of a 54 μm particle burning in a gas of T g = 300 K with X O2 = 0.21.…”