Experimental study on the spatial distribution of particle rotation in the upper dilute zone of a cold CFB riser

作     者：Xue-cheng WU Qin-hui WANG Chen TIAN Zhong-yang LUO Meng-xiang FANG Ke-fa CEN 

作者机构：State Key Laboratory of Clean Energy Utilization Zhejiang University Hangzhou 310027 China 

出 版 物：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 (浙江大学学报（英文版）A辑（应用物理与工程）)

年 卷 期：2008年第9卷第7期

页      面：922-931页

核心收录：

学科分类：080701[工学-工程热物理] 080703[工学-动力机械及工程] 08[工学] 0807[工学-动力工程及工程热物理] 

基　　金：the National Key Technologies Supporting Program of China during the 11th Five-Year Plan Period (No. 2006BAA03B01) the China Postdoctoral Science Foundation(No. 20070421165) 

主　　题：Particle rotation Gas-solid two-phase flow Circulating fluidized bed (CFB) 

摘      要：Particle rotation plays an important role in gas-solid flows. This paper presents an experimental investigation on the spatial distribution of average rotation speed for glass beads in the upper dilute zone of a cold circulating fluidized bed(CFB) riser. It is shown that in the horizontal direction,the average rotation speed in the near-wall area is larger than that in the center area,while in the vertical direction,it decreases as the height increases. The reason resulting in this distribution is analyzed by considering several factors including particle size,particle shape,particle number density,particle collision behavior,and the surrounding flow field,etc. The effects of CFB operation conditions on the spatial distribution of average rotation speed are also studied. The results show that the increasing superficial gas velocity increases the average rotation speed of particles in the near wall area but takes nearly no effect on that in the center area. The external solids mass flux,however,takes the opposite effect. It is found that the average rotation speeds of particles in both areas are increased as the total amount of bed material increases.