Transient Gas/Solid Flow Characteristics in Gas-Solid Cyclone Reactor Based on Euler/Lagrange Approach

A downward gas-solid cyclone reactor was designed for fluid catalytic cracking. The way mass and heat transfer of reactants is changed due to the swirling flow field in the new type reactor. A comprehensive three-dimensional numerical model was developed to deeper interpret the transient gas/solid flow behaviors in gas-solid cyclone reactor (GSCR). The continuous phase was modeled with turbulent computational fluid dynamics model and the dispersed phase was modeled with discrete phase model. The simulated dynamic pressure drop was agreed reasonably well with experiment. In addition, the solid flow pattern, particle concentration and gas velocity and kinetic energy were described respectively using the model. Simulated results show that the distribution of particle concentration is asymmetrical on the 0°-180°section and heterogeneous in time series. Particle groups with low kinetic energy were observed in conical segment and separation region. The phase interface of the gas and solid on different cross-section is obtained. Meanwhile, it can be seen that the size of the particle group is constantly changing. Gas phase has a higher downward angle in annular region and separation region than in mixing region. Besides, the velocity in the annulus is larger. The radial velocity distribution showed that the air velocity influenced by particle accumulation is not significant as its turbulent pulsation. Tangential and axial kinetic energy are accounting for 96.69%-97.11% of total kinetic energy and thus dominant.