Gas cyclones are common device in various industries to separate solid particles and/or droplets from gas streams. Nonetheless, the mathematical modelling of gas cyclone has been very challenging since huge number of multi-sized particles are involved in the system. In this work, a numerical study of the gas–solid flow in a gas cyclone with wide range of particle size distribution (from 1 to 200 µm) is carried out by developing a coarse-grained combined Discrete Element Method (DEM) and Computational Fluid Dynamics (CFD) model. It shows that the coarse-grained CFD-DEM model is able to capture the typical flow features in a gas cyclone including the solid strands and dust ceiling phenomena. It also shows that modelling of van der Waals force is critical for the prediction of separation efficiency in gas cyclone especially for fine particles. Furthermore, it is tried to explain how the dust ceiling is formed.

气旋分离器是各种工业中用于从气流中分离固体颗粒和/或液滴的常用设备。尽管如此，由于系统中涉及大量多尺寸颗粒，因此气体旋流器的数学建模一直非常具有挑战性。在这项工作中，通过开发粗粒度组合离散元方法 (DEM) 和计算流体，对具有广泛粒度分布（从 1 到 200 µm）的气旋分离器中的气固流动进行了数值研究动力学 (CFD) 模型。它表明，粗粒度 CFD-DEM 模型能够捕捉气体旋流器中的典型流动特征，包括固体股和尘埃天花板现象。它还表明，范德华力的建模对于预测气体旋流器中的分离效率至关重要，尤其是对于细颗粒。