Analysis of particle trajectories in a quick-contact cyclone reactor using a discrete phase model

Abstract

ABSTRACTThe Eulerian–Lagrangian approach with a discrete phase model (DPM) is used to investigate the motion trajectories of the particles at the range of 1–50 μm in the quick-contact cyclone reactor, in which the cracking reactions and the separations of catalysts and products can occur respectively and simultaneously. The results show that the typical motion trajectories of the particles in the quick-contact cyclone reactor can be described as three types: trapping, escaping and dust ring. The first typical motion of particles corresponds to the particles successfully separated from the gas flow, while the other two types can lead to more coking and erosion in the reactor. Moreover, a pre-vortex flow is observed in the mixing-reaction chamber. Additionally, the grade separation efficiency of each particle size is also obtained by counting the numbers of escaping and capturing particles. The particles with diameter larger than 10 μm are separated completely from the gas. The reactor also has a strong capability to trap the particles of small diameters (5 μm <dp<10 μm). Both results indicate that the separation efficiency of the reactor has met the requirement as a primary separator. Compared with the experimental results, the separation efficiency in the simulated method is higher than 98% with errors of no more than 1.31%. It is illustrated that separation efficiency of the reactor can be predicted by CFD simulation.