Numerical simulation and optimization of hydrodynamics in a novel integral multi-jet spout-fluidized bed

摘要

The hydrodynamics in a novel integral multi jet spout-fluidized bed was simulated using both Eulerian-Eulerian approach and the kinetic theory of granular flows. The effect of side jet number and side jet width on gas-solid two phase flow in the integral multi-jet spout-fluidized bed (IMJSFB) was investigated. The CFD results show that when the number of side jet is greater than 1 (N = 2-5), a wave-like spout and stable spout structure is formed in the IMJSFB. Compared with simulation results in the single nozzle spouted bed, the profiles of particles' velocity and concentration along the radial direction in the IMJSFB become relatively flatter. The integral uniformity of particle velocity distribution in spouted bed can be enhanced by increasing delta/D-i. The partide flow factor (eta) decreases first and then increases with the increase of delta/D-i, and eta reaches its minimum value when delta/D-i = 0.208. On the whole, there is a set of optimal design parameters of side jet (N = 4, delta/D-i = 0208), at which, the fluidization quality particle phase in spout-fluidized bed reaches the optimum state while the bypass fluidizing air supply auxiliary equipment is omitted. The fluidization quality of particles in annulus can be significantly enhanced in the IMJSFB while the bypass fluidizing air supply auxiliary equipment is omitted. (C) 2018 Elsevier B.V. All rights reserved.