Sharif Digital Repository

Simulation runs have been conducted to predict the evolution of sand drying in conical spouted beds with a non-porous draft tube. In the simulation runs, the moisture content of the solid phase was assumed to be 7 % (kg water/kg sand). The simulation results were validated against experimental results reported by Olazar et al. and good agreement was obtained.Influences of various physical and geometrical parameters such as superficial gas velocity, inlet temperature, length and diameter of draft tube and initial moisture content on the sand drying were investigated. Temperature and gas velocity are the most important parameters for improving the drying process and reduce the drying time of... 

In this study the spouted bed with draft tube was investigated by discrete phase model for particulate phase and was tried to simulate the spouted bed with high precision by using of experimental data. So, the most accuracy combination of different parameters and sub models was specified. According to this study, the dispersed k-ԑ turbulence model and standard wall function make best prediction. Gidaspow drag model was used for prediction interaction between phases. This study include the effect of Saffman lift force and Rubinow-keller model was chosen for coefficient of Magnus lift force. In Addition, the solid movement pattern was studied in different area of bed especially in fountain... 

Spouted beds are widely used in various process industries as an appropriate gas-solid contacting device. Thus, it is of great importance to study their hydrodynamics as a way of improving their design and efficiency. Furthermore, adding a draft tube to spouted beds considerably changes their hydrodynamic behavior. In this research work, the influences of different parameters involved in the simulation of spouted beds were examined to choose the appropriate ones that can reproduce the experimental data reported in the literature. In this regard, Wen and Yu drag model, Lun et al. radial distribution function, a restitution coefficient of 0.95, and a specularity coefficient of 0.02 were chosen...