湍动流化床中的颗粒减速现象  

Particle Decelerating Regions in Turbulent Fluidized Bed

作　　者：吴诚[1] 高用祥 王丽军[1] 成有为[1] 李希[1] 

机构地区：[1]浙江大学化学工程与生物工程学院,浙江杭州310027

出　　处：《化学反应工程与工艺》2014年第5期385-390,共6页Chemical Reaction Engineering and Technology

基　　金：国家自然科学基金(U1162125);中央高校基本科研业务费专项资金资助(2013QNA4035)

摘　　要：采用PV6D型光纤探针测量了直径为200 mm与95 mm的2套湍动流化床装置中的颗粒速度分布,据此将湍动床在轴向上分成6个区域,分析了上部出口减速区与下部过渡段减速区的产生机理,考察了流化段高度、静床高、表观气速对颗粒减速区的影响。结果表明:上部减速区是扩大段所产生的,下部减速区则是由于固含率急剧变化所引起的;随流化段高度减小,上部减速区下降,相邻的充分发展区与加速区缩短乃至消失;下部减速区的位置随静床高的增加而升高,随表观气速的增大而下移,与过渡段的变化趋势一致。Particle velocity in a 95 mm ID and a 200 mm ID fluidized bed was measured with PV6D reflective optical fiber probe. Based on the velocity measurement results, the turbulent fluidized bed was divided into 6 regions. The generation mechanisms of decelerating regions of top section and transition section in turbulent fluidized bed were analysed. Effects of fluidization section height, static bed height and gas velocity on decelerating regions were investigated. The results showed that the decelerating region on the top is caused by discharge section, while the decelerating region on the bottom is caused by the rapid change of solid concentration. The decelerating region on the top declined with the decreased fluidization section height, and shortened the length of fully developed section and accelerating section or even made them disappear. While the decelerating region on the bottom rose with the static bed height and descended with the gas velocity. The variation trend of decelerating regions was in accord with the one of transition section.

关 键 词：湍动床 颗粒速度 减速区 光纤探针 

分 类 号：TQ021[化学工程]