A computational particle fluid-dynamics simulation of hydrodynamics in a three-dimensional full-loop circulating fluidized bed: Effects of particle-size distribution

Publication date: Available online 2 July 2019Source: ParticuologyAuthor(s): Hang Zhang, Youjun LuAbstractA computational particle fluid-dynamics model coupled with an energy-minimization multi-scale (EMMS) drag model was applied to investigate the influence of particle-size distribution on the hydrodynamics of a three-dimensional full-loop circulating fluidized bed. Different particle systems, including one monodisperse and two polydisperse cases, were investigated. The numerical model was validated by comparing its results with the experimental axial voidage distribution and solid mass flux. The EMMS drag model had a high accuracy in the computational particle fluid-dynamics simulation of the three-dimensional full-loop circulating fluidized bed. The total number of parcels in the system (Np) influenced the axial voidage distribution in the riser, especially at the lower part of the riser. Additional numerical simulation results showed that axial segregation by size was predicted in the two polydisperse cases and the segregation size increased with an increase in the number of size classes. The axial voidage distribution at the lower portion of the riser was significantly influenced by particle-size distribution. However, radial segregation could only be correctly predicted in the upper region of the riser in the polydisperse case of three solid species.Graphical abstract

Source: Particuology - July 3, 2019 Category: Science Source Type: research