Numerical Analysis of Drying Characteristics of Wet Material Immersed in Fluidized Bed of Inert Particles

摘要

The drying characteristics of a relatively large wet material immersed in a fluidized bed of inert particles were examined theoretically. Calculations of heat transfer and evaporation of water on the material surface were included in a discrete element method-computational fluid dynamics (DEM-CFD) simulation. Only the preheating and constant drying rate periods were considered in the simulation. Our simulation made it possible to calculate the relation between the behavior of the fluidizing particles and the drying characteristics. The drying rate increased with an increase in the number of fluidizing particles in contact with the material and the number of fluidizing particles changed with time; that is, the drying rate fluctuated. When the drying rate increased, the fluid temperature decreased and the vapor content of the fluid increased around the material; that is, the temperature and vapor content of the fluid were associated with the behavior of the fluidizing particles.