Solids behavior in dilute zone of a CFB riser under turbulent conditions

作     者：Abdelghafour Zaabout Hervé Bournot René Occelli Abdeslam Draoui 

作者机构：IUSTI Technople de Chateau Gombert 5rue Enrico FERMI Laboratoire d'EnergétiqueUniversité Abdelmalek Essaadi 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2011年第9卷第6期

页      面：598-605页

核心收录：

学科分类：081704[工学-应用化学] 08[工学] 0817[工学-化学工程与技术] 081701[工学-化学工程] 

主　　题：Bed structure Turbulent fluidization regime Solid phase behavior Phase Doppler anemometer Particle velocity Transition velocity 

摘      要：The behavior of the solid phase in the upper zone of a circulating fluidized bed riser was studied using a phase Doppler anemometer. Glass particles of mean diameter 107μm and superficial gas velocities UE covering the turbulent and the beginning of the fast fluidization regime were investigated. Three static bed heights were tested. Ascending and descending particles were found co-existing under all oper ating conditions tested, and at all measurement locations. Superficial gas velocity proved/happened to have a larger effect on descending particles at the wall and on ascending particles in the central region. Transversal particle velocities in both directions （toward the center and toward the wall） behaved rela- tively equivalently, with only slight difference observed at the wall. However, observation of the number of particles moving in either transversal direction showed a change in bed structure when increasing Ug. Furthermore, a balance was constantly observed between the core zone and the annulus zone where the mutual mass transfer between these two zones occurred continuously. Transition from a slow to a fast particle motion was accompanied by a transition to high levels of velocity fluctuations, and was found corresponding to the appearance of significant solid particle flow rate.