Multi-scale simulation of particle density effects on hydrodynamics in dense gas-solid fluidized beds

Abstract

Gas-solid fluidization has gained prominence in chemical engineering, particularly for processes involving high-density particles. However, a notable dearth of research on the fundamental fluidization of high-density particles exists, distinct from the well-studied low-density particles. This knowledge gap presents significant challenges in designing and operating fluidized beds for such processes. In this study, we employ the CPFD scheme to comprehensively investigate how particle density affects hydrodynamics. Simulation results consistently align with experiments for pressure drop and minimum fluidization velocity, underscoring the model reliability. Importantly, typical empirical correlations for predicting minimum fluidization velocity display substantial inaccuracies, particularly for high-density particles. Additionally, we identify marked disparities in fundamental fluidization behavior between high and low-density particles, with increasing density leading to deteriorating fluidization performance, characterized by larger bubbles, defluidized regions, gas streaming, and reduced bed expansion ratios. Investigating high-density particle gas-solid fluidization systems promises valuable theoretical insights, bridging the gap between theory and practice.