Numerical investigation of the penetrating gas flow into particle clusters for circulating fluidized beds

Gas-solid circulating fluidized beds (CFBs) are widely used as reactors in industry with performances heavily re-lying on the interaction between gas and particles. In a CFB, some particles stay dispersed, while other particles aggregate to form dense and large clusters. As the gas-particle interaction is simple for dispersed particles, the prediction of reactor performances calls for a thorough analysis of the gas-cluster interaction. In the literature, cluster properties have been characterized extensively. However, how the gas interacts with clusters has not been quantified systematically yet. In this work, the gas-cluster interaction was quantified numerically by char-acterizing the penetrating gas flow into clusters. With 99 simulations, influences of the particle randomness, clus-ter solids holdup, cluster diameter, particle diameter, superficial gas velocity and fluid properties on the gas -cluster interaction were investigated systematically. Then, an empirical correlation was proposed to quantify the gas-cluster interaction, significantly contributing to the design and optimization of CFBs. (c) 2021 Elsevier B.V. All rights reserved.