Simulation of Powder Motion with Particle Contact Model Including Intervening Liquid

Abstract

The control of packed bed permeability in blast furnace is an important issue to realize highly efficient and stable operation of blast furnace under low carbon condition. The powder accumulation in the packed bed deteriorates the permeability, thus it is necessary to understand the powder behavior in the packed bed. Recently it was revealed that the existence of liquid in the bed had drastic effect on the motion and the accumulation of powder in the bed. In this study a mathematical model to describe the behavior of powder particle under liquid existing condition was developed using discrete element method. The model took into account cohesive force, normal viscous force, sheer viscous force and lubrication due to the liquid film. The model was validated by the comparison of the particle trajectories under various liquid properties. The model was applied to the simulation of passing behavior of the powder particles through the opening among three coarse spherical particles, and successfully reproduced the accumulation behavior under wetting condition.

Dynamic analysis of blockage behavior of fine particles in a packed bed by discrete element method

“…Thus, in this work, the ratio of the larger sphere particle diameter and the fine particle diameter is 10 ( D = 10 d ) which is larger than the geometrical tapping threshold. This simulation condition is similar to many previous works [21–24]. After these large sphere particles are settled down under gravity to form a stable packing structure, the small fine particles are charged on the top of the packed bed.…”

“…Luo et al [23] investigated the blockage behaviour of cohesive fine particles in a simplified packing structure by means of DEM. The particle contact force model considering the intervening liquid was developed by Suzuki et al [24] for analysing the motion and the accumulation of powder in irrigated packed bed. Besides, the CFD-DEM studying the fine particles blockage was also attracted widely concerns.…”

An unresolved CFD-DEM method for studying migration and clogging of fine particles through a packed bed

“…The forces at play are the gravitational force m i g and the contact force between particles (consisting of damping forces in normal F dn,ij and tangential F dt,ij , as well as contact forces of normal F cn,ij and tangential F ct,ij ). The particle i is additionally exposed to two other forms of torques, such as the rolling friction torque M ij and the tangential torque T ij [28–30]. While M ij is brought on by rolling friction, T ij is the torque that particle j or the wall applies to particle i as a result of the tangential force.…”

“…Shi et al performed a micro-numerical analysis of diaphragm blockage by simulating the migration and accumulation of soil particles with a CFD-DEM model [27]. Suzuki et al developed a particle contact force model considering an intermediate liquid for examining the movement and deposition of powders [28]. Satou et al created a 3D CFD-DEM method to better comprehend the obstructive impact of the upflowed gas and diameter ratio on the fixed bed, which results in fines clogging development and infiltration criteria [29].…”