In this work, a new methodology is introduced to calculate the solids mixing rate in dense gas-fluidized beds using the two-fluid model. The implementation of this methodology into an existing two-fluid model code was carefully verified. The solids phase continuity equation was satisfied using our method, and the sensitivity of the computational results to the time step, computational cell size, and discretization scheme was investigated to determine the optimal simulation settings. Using these simulation settings, the degree of solids mixing was observed to rapidly (exponentially) increase with increasing operating pressure and linearly decrease with increasing bed diameter. Our novel methodology can be applied to analyze mixing processes in large lab-scale beds as an alternative to existing time-consuming simulation techniques such as computational fluid dynamics combined with the discrete element model.

在这项工作中，引入了一种新的方法，使用双流体模型来计算致密气体流化床中的固体混合速率。仔细验证了此方法在现有两流体模型代码中的实现。使用我们的方法满足了固相连续性方程，并且研究了计算结果对时间步长，计算像元大小和离散化方案的敏感性，以确定最佳的仿真设置。使用这些模拟设置，观察到固体混合程度随操作压力的增加而迅速（呈指数增长），随床直径的增加而呈线性下降。