Flow hydrodynamics in a gas–solid fluidized bed reactor with two reaction zones
Shuaishuai Zhou, Chunxi Lu*, Mengxi Liu*
A novel reactor with two reaction zones is proposed for pyridine synthesis. The flow hydrodynamics were investigated in experiments. Pressure taps and a PV-6D optical fiber were used to measure the pressure fluctuation and particle concentration, respectively. Hilbert–Huang analysis was adopted to distinguish the flow patterns through pressure fluctuation. Results show that the flow patterns are bubbling fluidization and fast fluidization in the regions below (reaction zone I) and above (reaction zone II) the nozzles, respectively. The radial distribution of the cluster time fraction was obtained through signal waves of the particle concentration. Analysis of the cluster time fraction revealed two radial distributions. In the region around the nozzles, the cluster time fraction ranged from 0 to 0.2 and concentrated at radial positions r/R = 0–1, which resulted from unsymmetrical catalyst feeding. In reaction zone II, the cluster time fraction ranged from 0 to 0.2, and the radial distribution indicated a core–annulus structure.
Two reaction zones; Hilbert–Huang analysis; Flow pattern; Cluster time fraction