We describe the effectiveness of the coarse-grain model of the discrete element method (DEM) in solid mixing in a spouted bed. The coarse-grain model was developed originally to simulate large-scale DEM simulations efficiently, where the coarse-grain particle represents a group of original particles. In previous studies, the adequacy of the coarse-grain model was proven in a pneumatic conveying system and bubbling fluidized beds through verification and validation tests. In this study, the coarse-grain model has been applied to solid mixing in a spouted bed. Agreement of the mixing state is shown between an original particle system and coarse grain model systems. Subsequently, correlation between solid mixing and macroscopic behavior of the solid particles is examined in the present study. The macroscopic properties such as solid-particle spatial distribution, pressure drop and velocity distribution of the solid phase are confirmed to correspond quantitatively in the coarse-grain model and an original particle system. Finally, the calculation efficiency of the coarse-grain model is evaluated. Consequently, the coarse-grain model is shown to be able to efficiently investigate the solid mixing in a spouted bed.

我们描述了离散元素方法（DEM）的粗粒模型在喷射床中进行固体混合的有效性。粗粒模型最初是为了有效地模拟大规模DEM模拟而开发的，其中粗粒粒子代表一组原始粒子。在先前的研究中，通过验证和确认测试在气动输送系统和鼓泡流化床中证明了粗粒模型的适当性。在这项研究中，将粗粒模型应用于喷流床中的固体混合。原始粒子系统和粗粒模型系统之间显示出混合状态的一致性。随后，在本研究中检查了固体混合与固体颗粒的宏观行为之间的相关性。在粗颗粒模型和原始颗粒系统中，证实了诸如固相空间分布，压降和固相速度分布等宏观性质在定量上是对应的。最后，对粗粒模型的计算效率进行了评估。因此，粗粒模型显示出能够有效地研究喷射床中的固体混合。