Powder Technology, Vol.354, 696-708, 2019
Transport hydrodynamics of particles in a gas-solid cyclone reactor using a dense discrete phase model and a particle size segmentation method
A downward gas-solid cyclone reactor (GSCR) was designed for the fluid catalytic cracking. It is expected that the over-cracking of light products can be suppressed by the gradient distribution and short residence time of particles. Besides, the mass and heat transfer of reactants are enhanced due to the existence of the swirling flow field in the new reactor. The dense discrete phase model (DDPM) coupled with particle size segmentation method (PSSM) was adopted to interpret particle transport hydrodynamics in the GSCR The bed density and pressure drop of simulations were compared with those obtained experimentally. Simulated results show that the flow of gas and solids reaches their own macroscopically steady state after 2 s. In addition, the cluster-ring with a dilute "tail" and a dense "head" is observed in the numerical and experimental result. Furthermore, the mixing chamber is further divided into a diffusion chamber and an agglomeration chamber according to the distribution of axial bed density and the structure of the GSCR. The equal-area annulus method was proposed to investigate the radial particle distribution. In addition, the proportion of particles with diameter >0.10 mm is rarely in the diffusion chamber, whereas the number of particle sizes ranging from 0.08-0.11 mm accounts for a large proportion (66.39% at least) in other chambers. (C) 2019 Published by Elsevier B.V.