Three-Dimensional Modeling of an Ironmaking Blast Furnace with a Layered Cohesive Zone

A three-dimensional (3D) parallel process model simulating ironmaking blast furnaces (BFs) has been developed using computational fluid dynamics (CFD). It explicitly describes the layered burden and cohesive zone (CZ), gas and liquid re-distribution near raceways, trickling liquid flow in the CZ and dripping zone, and stockline variation. The applicability of the model is confirmed by the reasonable agreement between predicted and measured in-furnace states and global performance under experimental and industrial conditions. Using this model, the 3D characteristics of in-furnace states for a 5000 m³ commercial BF with 40 tuyeres are revealed. Also, it is used to assess the commonly used slot, axisymmetric, sector and full 3D models, which may treat burden distribution as well as gas and liquid flows around raceways differently. The results reveal that the sector and full 3D models are nearly the same; the slot model over-predicts the coke rate up to 13 kg/tHM, and the axisymmetric model gives slightly higher productivity and liquid temperature. These differences are clarified by analyzing model simplifications and their impacts on in-furnace states.