Discrete Particle Simulation of Solid Flow in a Model Blast Furnace

Abstract

This paper reports a numerical study of solid flow in a model blast furnace under simplified conditions by means of discrete particle simulation (DPS). The applicability of the proposed DPS approach is validated from its good agreement with the experiment in terms of solid flow patterns. It is shown that the DPS is able to generate a stagnant zone without any need for any arbitrary treatment, and capture the main features of solid flow within the furnace at a microscopic level. The results confirm that the solid flow in a blast furnace can be divided into four different flow regions. However, the flow is strongly influenced by the front and rear walls in a 2D slot model furnace whereas the predicted stagnant zone decreases significantly with wall sliding friction. In a 3D model with periodic boundary conditions incorporated, a smaller stagnant zone is obtained. The effects of solid flow rate, particle properties such as sliding and rolling friction coefficients on the solid flow are also investigated. The results are analysed in terms of solid flow patterns, solid velocity field, porosity distribution and normal force structure. The implication to blast furnace operation is discussed.

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

“…The four solid flow regions are clearly observed, with a stagnant zone generated in the lower central part. These solid flow zones can be reproduced in the present DEM simulation, 57) as shown in Fig. 3(b).…”

“…Hence, the development of a more comprehensive theory and associated experimental techniques to quantify the interaction forces between particles and between particle and fluid under various conditions will remain an active research area. As an example, Table 2 lists the equations employed by Yu and colleagues 19,47,48,50,51,57) to calculate the forces and torques.…”

“…57,73) For example, in Fig. 3(a), the solid flow pattern observed from the physical experiment is shown.…”

“…Hence, the development of a more comprehensive theory and associated experimental techniques to quantify the interaction forces between particles and between particle and fluid under various conditions will remain an active research area. As an example, Table 2 lists the equations employed by Yu and colleagues 19,47,48,50,51,57) to calculate the forces and torques.When applied to particle-fluid flow, DEM needs to be coupled with Computational Fluid Dynamics (CFD) that describes the flow of fluids such as gas and/or liquid based on the Navier-Stokes equations, giving the so-called DEM-CFD or combined continuum and discrete model (CCDM). 51,58,59) In principle, the coupling between the continuum fluid and discrete particles can be made at different time and length scales.…”

Mathematical Model of Solid Flow Behavior in a Real Dimension Blast Furnace

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] On the other hand, the discrete method is based on the Newton's second law of motion and is focused on the behavior of each and all individual particles in the system. [22][23][24][25][26][27][28][29][30] The discrete element method (DEM) is originally developed by Cundall and Strack 31) and is very effective to model granular materials. However, it is still very time-expensive to use this method for simulations of a blast furnace, even considering the development of computers hardware.…”