An Exploratory Study of Annular Fluidized Bed Reactor with High Centrifugal Acceleration for Some Industrial Processes

This study explored the feasibility of gas-solids fluidized bed reactor under high centrifugal acceleration for some chemical processes. The goal was to assess an ideal gas-solids contacting device with high slip velocity so that one can achieve intensified heat and mass transfer as well as the ability to fluidize hard-to-handle cohesive powders. A series of CFD-DEM simulations was first conducted for a vortex bed reactor with multiple tangential gas injections to illustrate the basic concept for group B particles in a small-scale system operated under the moving bed flow regime. The simulation results demonstrated a desired continuous operation with near-plug axial solids flow and high gas-solids slip velocity. Simple force analyses were then conducted to identify some key challenges and limitations in the design and operation of a vortex bed reactor. The analyses suggested that it would be beneficial to decouple tangential and radial driving forces for maintaining a stable centrifugal force field for reactor scale-up. A rotating fluidized bed was then studied which imposed high centrifugal force on the dense solids bed through the rotating column wall. The two-fluid model (TFM) simulations were used to carry out a virtual scale-up exercise of a horizontal rotating fluidized bed. Major challenges in the stable operation of rotating fluidized beds at large scales were discussed and a possible method to mitigate those challenges was proposed and evaluated numerically.