内置螺旋挡板流化床颗粒停留时间分布  

Residence Time Distribution of Particles in Fluidized Bed with Spiral Internal

作　　者：都艺伟 吴新[1] 刘道洁[1] 李军辉[1] Yiwei DU;Xin WU;Daojie LIU;Junhui LI(Key Laboratory of Energy Conversion and Process Control of Ministry of Education Southeast University, Nanjing, Jiangsu 210096, China)

机构地区：[1]东南大学能源热转换及其过程控制测控教育部重点实验室

出　　处：《过程工程学报》2018年第3期484-490,共7页The Chinese Journal of Process Engineering

基　　金：国家重点研发计划资助项目(编号:2016YFB0600602)

摘　　要：采用脉冲示踪法在内置螺旋挡板冷态鼓泡流化床上研究了螺旋挡板、加料速率、流化风速、颗粒粒径和床料高度对颗粒在流化床内停留时间分布的影响.结果表明,颗粒停留时间的无量纲方差从无螺旋挡板时的0.558减小到有螺旋挡板时的0.085,螺旋挡板可有效抑制颗粒返混,增大颗粒运动的平推流趋势;加料速率增大为约2倍时,停留时间减小为约50%,流动更趋向于平推流;床料高度增加,颗粒返混加剧,颗粒平均停留时间及无量纲方差均增大,颗粒运动向全混流靠近;随流化风速增大,颗粒平均停留时间变长;实验范围内,颗粒粒径对颗粒停留时间分布影响不大.Effects of spiral internal, solid feeding rate, fluidized gas velocity, particle size and bed height on the particle residence time distribution were investigated in a cold bubbling fluidized bed using the tracer technique. The results showed that the dimensionless variance of particle residence time reduced from 0.558 without spiral internal to 0.085 with a spiral internal, indicating that the spiral internal helped restrain the back mixing of particles and made the flow approach the plug flow. When the solid feeding rate was doubled, the residence time of particles decreased by approximately 50% and the flow was closer to plug flow. As the increased bed height caused severe back mixing, both average residence time and dimensionless variance increased and the solid flow tended to be complete stirred flow. The average residence time of particles extended with the increasing of fluidized gas velocity. Particle size had a little effect on the residence time distribution under present experimental conditions.

关 键 词：螺旋挡板 流化床双床结构 颗粒 停留时间分布 

分 类 号：TQ021.4[化学工程]