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Investigation on the Hydrodynamic Behavior of Spouted beds with Draft Tube

Morad Soltani, Pooria | 2018

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 51074 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Molaei Dehkordi, Asghar
  7. Abstract:
  8. 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 and applied. Using these parameter values, the effects of gas superficial velocity, the draft tube diameter, and the entrainment height were explored. The simulation results obtained show good agreement with the experimental data. Moreover, by increasing the gas velocity, the velocity of solid particles rises and as the draft tube diameter and entrainment height increase, the velocity of solids decreases. Additionally, the developed model was used to predict the effects of particle diameter and density on the particle velocity and the bed fountain height. The simulation results clearly indicate that with an increase of 25% in the particle diameter, their axial velocity and the fountain height decrease by 19% and 10%, respectively. Also, increasing the solids density by 25% results in 14% and 8% decrease in the axial particle velocity and the fountain height, respectively. Finally, the simulation results of another bed were presented and discussed. After a brief comparison between the simulation results of two simulated beds, the effects of static bed height and the particle density were investigated carefully
  9. Keywords:
  10. Draft Tube ; Simulation ; Eulerian-Eulerian Approach ; Computational Fluid Dynamics (CFD) ; Spouted Bed ; Solids Velocity Profile

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