Recent Advances in the Modelling of Solid Flows in the Blast Furnace

Abstract

The solid flow inside a blast furnace is modelled using a standalone finite element program and a constitutive equation called hypo‐plastic, in order to better simulate the granular material behaviour. The parameters of this constitutive equation are calibrated using data obtained from simple soil mechanics tests on coke and sinter materials, such as triaxial and oedometric devices. Steady velocity, stress and void fraction fields are obtained after several iterations of the code. Knowledge of the solids velocity field makes it possible to determine the dead man profile, as well as its renewal kinetics. Burden trajectories and time lines are also computed. Knowledge of the stress field makes it possible to compute pressures acting on the burden as well as on the walls. Finally, knowledge of void fraction field makes it possible to determine gas paths. The solid flow model was validated on 2D and 3D small‐scale cold blast furnaces, but the simulations never required any tuning parameter. This code is in fact an invaluable tool to determine the effect of blast furnace profile on solid flow conditions, and reciprocally.

Discrete Element Method-Computational Fluid Dynamic Simulation of the Materials Flow in an Iron-making Blast Furnace

“…3) and Nogami et al 4) The hypo-plasticity model for solid flow was developed by Zaïmi et al 5,6) The great advantage of this model over the previous is the ability to predict the deadman instead of requiring a predefined one. A solid flow model was published by Zhang et al,7,8) where the stress due to flowing particle interaction is composed of two components; rate-dependent and rate-independent.…”

“…The approach can give good results on a macroscopic level but is highly dependent on empirical relations, rather than fundamentals. As mentioned, a significant amount of research has been done, example of which is the four-fluid or multi-fluid model by Yagi 1) in which solid flow is described by the viscous flow model and further applied by Austin et al, 2) De Castro et al 3) and Nogami et al 4) The hypo-plasticity model for solid flow was developed by Zaïmi et al 5,6) The great advantage of this model over the previous is the ability to predict the deadman instead of requiring a predefined one. A solid flow model was published by Zhang et al, 7,8) where the stress due to flowing particle interaction is composed of two components; rate-dependent and rate-independent.…”