Particle flow and behavior at bell-less charging of the blast furnace

The burden distribution in the upper part of the blast furnace is one of the most important factors controlling the gas flow distribution, and therefore the efficiency of heat and mass transfer and chemical reactions between gas and solids in the process. This work studies burden profiles formed by pellets and coke dumps using experiments and simulation. Comparing results from DEM simulation with findings from a small-scale experimental system, it is demonstrated that the modeling technique is feasible. The rotation of the chute was found to cause a shift of the particles off from the bottom center line of the chute. In the burden layer formation, coke forms a pile at the intersection of falling trajectory and burden surface, while pellets spread towards the furnace center, simultaneously occupying the space between the larger coke particles after the pellet pile has reached the maximum natural angle. Particles with a high angular velocity were found to be more likely to enter the region close to the furnace wall. It is also shown that reducing the shear modulus of the burden material in the simulation is an efficient method to increase the calculating speed of the DEM without significant effect on the results of the simulation.