DEM Study of Solid Flow in COREX Shaft Furnace with Areal Gas Distribution Beams

摘要

In this work, a three-dimensional DEM-based model is used to investigate solid flow including burden descending behaviour and particle segregation in the shaft furnace of ironmaking COREX. The model was validated by the reasonable agreements between simulations and experiments. The results confirm that the Areal Gas Distribution (AGD) beams affect solid flow in the bustle zone significantly but slightly at the lower part of the furnace. A triangle-shaped free zone is observed below the AGD beams, which will be the main path for gas flow along the centre of shaft furnace. The AGD beams can lead to particle segregation in the shaft furnace. The coke and flux particles can roll easily from the centre to the zone below the AGD. As a result, the normalized mass fractions of coke and flux are larger than 1.0 near the screw outlet located below the AGD beams. In addition, three new designs of AGD beams are proposed in this work. The simulation results indicate that the design with three AGD beams is regarded as the optimal option due to uniform burden descent and convenient installation. The model provides a cost-effective tool to understand and optimize the solid flow in the shaft furnace of COREX.