Liquid–solid fluidized beds are widely used in industrial processes, such as polymerization, mineral processing, and water treatment. Among these processes, particle fluidization behaviors perform a significant function in determining heat and mass transfer performance. In this study, a large set of expansion experiments are performed to investigate the effects of the particle density, particle size, and liquid superficial velocity on bed expansion height and bed porosity. The drag coefficient is obtained based on experimental data. The relationship between drag coefficient and Reynolds number, Froude number and Stokes number is clarified, and an effective drag closure for coarse coal particle fluidization in the transitional flow regime is proposed. Then the developed drag coefficient correlation is incorporated into liquid–solid two-phase flow model to predict the bed expansion height. The output predictions agree well with the experimental data, ensuring the accuracy of the proposed drag closure.

液固流化床广泛用于工业过程，如聚合、矿物加工和水处理。在这些过程中，颗粒流化行为在确定传热和传质性能方面发挥着重要作用。在这项研究中，进行了大量膨胀实验来研究颗粒密度、粒度和液体表观速度对床膨胀高度和床孔隙率的影响。阻力系数是基于实验数据获得的。阐明了阻力系数与雷诺数、弗劳德数和斯托克斯数之间的关系，提出了过渡流态下粗煤颗粒流化的有效阻力闭合。然后将开发的阻力系数相关性结合到液固两相流模型中以预测床膨胀高度。输出预测与实验数据非常吻合，确保了所提出的阻力闭合的准确性。