原生纳米级颗粒的聚团散式流态化

在内径为 35mm的小型玻璃流化床中考察了平均原生粒径为 16nm的SiO₂ 颗粒的流化行为 .实验发现 :当操作气速远远超过原生纳米颗粒的最小流化气速时 ,这种超细颗粒可以通过自团聚实现稳定、均匀的散式流化 ,并可获得比GeldartA类颗粒更高的床层膨胀比和更宽的散式操作区 .由于原生纳米级SiO₂ 颗粒在流化时形成的团聚物具有较大的粒径和很小的密度 ,使得该气固体系的流化行为与液固体系有许多相似之处 ,该过程对于研究气固流态化的散式化具有重要意义

AGGLOMERATE PARTICULATE FLUIDIZATION OF PRIMARY NANO-PARTICLES

The fluidization characteristics of 16 nm SiO 2 powder were investigated in a small-scale transparent column. Experiments indicated that agglomerates were formed during fluidization when the gas velocity exceeded the apparent minimum fluidization velocity of the primary particles, which could be smoothly and uniformly fluidized . Surprisingly, in this case the bed expansion was fairly higher than that of Geldart-A particles, and the particulate region was rather broad. With stable,light and large agglomerates, the fluidization behavior was something like that of a liquid-solid fluidized bed.