Influence of particle shape on microstructure and heat transfer characteristics in blast furnace raceway with CFD-DEM approach

Coupled computational fluid dynamics and discrete element method (CFD-DEM) simulations are conducted to investigate the influence of particle shape on microstructure and heat transfer characteristics in a blast furnace (BF) raceway. Spherical and non-spherical particles including tetrahedron-like and octahedron-like shapes are involved in this work. The applicability of the coupled approach and the accuracy of combined sphere method (CSM) to investigate the kinetic and thermodynamic behaviors are validated firstly based on the experimental results. Then, the influences of particle shape on raceway formation, microstructure, and particle temperature evolution are comprehensively explored. The numerical results show that the tetrahedron-like particle system presents a relatively stronger interlocking efficiency and thus leads to a smaller raceway size. Additionally, the non-uniform performance of temperature in this system is more striking than the other two cases. However, the bigger raceway size exists in the octahedron-like particle system and the average particle temperature is also higher than other cases; meanwhile, this system possesses more powerful rotational kinetic energy but lower drag force required to form and maintain the raceway than tetrahedron-like system under the same inlet velocity. These findings could be beneficial for the in-depth understanding of microstructure and heat transfer characteristics within a BF raceway. (C) 2019 Elsevier B.V. All rights reserved.