Two-Fluid-Model-Based Full Physics Simulations of Mixing in Noncohesive Wet Fluidized Beds

Mixing in a noncohesive wet fluidized bed was studied using the two-fluid model (TFM) and a zero-dimensional (0D) approach. The employed TFM was extended to simulate droplet deposition on the particles, droplet evaporation, and particle drying. To quantify the bed uniformity, the variance of temperature and the particles' loss on drying (LoD) field were computed. Subsequently, our TFM simulation data is used to support the assumptions adopted in our 0D model. Specifically, the simulation results suggest the formation of two well-mixed zones: a spraying/wetting zone and a drying zone. Furthermore, it was demonstrated that the 0D model can accurately predict the gas and particle temperatures, as well as the moisture content with a maximum error of 4.3% when the following criteria are met: (i) low enough temperature and LoD variance (i.e., less than 5%); (ii) deep droplet penetration into the bed; (iii) no droplet loss.