Simulation of Gas-Solid Mixing and Flow in the Feedstock Zone of a Riser by EMMS Drag Model
1. State Key Laboratory of Heavy Oil, China University of Petroleum, Beijing 102249, China; 2. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080, China
Abstract Feedstock injection zone is the most critical area for fluid catalytic cracking (FCC) riser reactor. The 3-D computational fluid dynamics (CFD) simulation of gas-solid two-phase mixing and flow in this zone was performed by an energy-minimization multi-scale (EMMS) drag model. The dynamic behavior of the mixing and flow was discussed by comparing the simulation results with experimental data. Moreover, the two-phase mixing and flow in different feedstock injection structures with various angles of feedstock nozzles relative to the axes of riser reactor were simulated. The gas-solid inhomogeneous mixing and the secondary flow were analyzed. The results show that the behaviors of gas-solid two-phase mixing and flow in the feedstock injection zone can be depicted well by the EMMS drag model. Furthermore, when the angles of the feedstock jet up to the riser, it will be appeared that the gas-solid two-phase mixing sufficiently require more time to reach the steady flow. The cluster together and back mixing of a large number of particles in the vicinity of riser wall are inevitable, which results in the coke in industry. Finally, a novel way is proposed to realize gas-solid two-phase uniform mixing and flow as well as to control the secondary flow reasonably.
Chen Sheng1,2,Wang Wei2 et al. Simulation of Gas-Solid Mixing and Flow in the Feedstock Zone of a Riser by EMMS Drag Model[J]. 化学反应工程与工艺, 2014, 30(1): 71-78.
Chen Sheng1,2,Wang Wei2 et al. Simulation of Gas-Solid Mixing and Flow in the Feedstock Zone of a Riser by EMMS Drag Model[J]. 化学反应工程与工艺, 2014, 30(1): 71-78.
