Flow and heat mass performances of wet particle drying process based on liquid volume-varying bridge force

Abstract

Drying treatment of wet particle system is an important industrial process, involving flow and heat mass transfer multiple process. It has been widely used in many industrial processes, such as renewable energy usage and food storage. In this work, we numerically analyzed the heat mass transfer and flow behaviors of a wet particle system. Liquid volume-varying bridge force model was developed, and taking into account water evaporation. The numerical model data were validated, and we found good agreement with respect to hot particles during the cooling period. For a better explanation of the interactions among flow, heat and mass transfer, we calculated the distribution of particle Nusselt (Nup) and Sherwood (Shp) as a function of Reynolds (Rep), and interaction relationships between multiple processes were evaluated. Moreover, near the walls, lower gas velocity and higher particle volume fraction resulted in weak heat transfer characteristics. If this heat transfer coefficient is improved and addressed appropriately, emulsion phase, which accounts for major proportion as potential underlying cause of forming agglomeration structure, will be effectively avoided and kept to accepted level. This is important for the wet particle handling in actual industrial processes.