纳米级SiO_2颗粒流化床的塌落行为  

BED COLLAPSE BEHAVIOR OF SiO_2 NANO-PARTICLES

作　　者：王垚[1] 金涌[1] 魏飞[1] 骆添[1] 

机构地区：[1]清华大学化学工程系,北京100084

出　　处：《化工学报》2001年第11期957-962,共6页CIESC Journal

摘　　要：在直径为 35mm的小型流化床中考察了纳米级SiO2 颗粒 (商品牌号R972 )的床层塌落行为 .该种经过表面改性的颗粒可以通过自团聚形成稳定、均匀的聚团散式流化 .实验证明 ,这种颗粒的床层塌落行为明显不同于普通的GeldartA类与C类颗粒 ,其塌落过程可分为恒速沉降阶段和减速压实阶段 .通过对塌落速率的分析 。The collapse behavior of nano-particle SiO2 (R972) is investigated in a 35 mm diameter fluidized bed. This powder can be easily and uniformly fluidized via self-aggregation. Collapse experiments indicate that the bed collapse curve of SiO2 particles is different from that of Geldart Group A and C particles. By analyzing the collapsing velocity, the bed collapse process can be clearly divided into two stages: a rapid initial sedimentation stage with constant velocity, and a decelerating stage of solids consolidation for the incompletely suspended agglomerates. The bed collapse mechanism of agglomerate particulate fluidization is proposed.

关 键 词：纳米颗粒 聚团 散式流化 床层塌落 二氧化硅 流化床 流态化行为 

分 类 号：TQ051.13[化学工程] TB383[一般工业技术—材料科学与工程]