Laser-based planar imaging of nano-particle fluidization: Part I—determination of aggregate size and shape
Laser-based planar imaging of nano-particle fluidization: Part I—determination of aggregate size and shape
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DOI：
10.1016/j.ces.2006.04.012
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发表时间：
2006-08
影响因子：
4.7
通讯作者：
X. S. Wang;V. Palero;J. Soria;M. Rhodes
中科院分区：
文献类型：
--
作者：
X. S. Wang;V. Palero;J. Soria;M. Rhodes
本文研究的重点是纳米颗粒流态化中团聚体尺寸的确定和表观气速对颗粒聚集的影响。一次粒度为12 nm的Degussa Aerosil R974粉末在46 mm正方形截面的玻璃容器中以氮气流态化。基于激光的平面成像实验的表观气速约为最小流态化速度的4-8倍。使用高分辨率数码相机的原位平面激光片状照明记录了纳米颗粒的聚集体。发现聚集体具有广泛的尺寸分布，并包含非常小的尺寸的重要成分。团聚体的平均尺寸随着表观气速的增加而减小，而团聚体的平均球度对表观气速的变化不敏感。基于平面激光薄片成像的测量结果与以前的研究结果以及现有模型的预测进行了比较。
The focus of this work is the determination of the size of aggregates and the effect of superficial gas velocity on particle aggregation in a nano-particle fluidized bed. Degussa Aerosil R974 powder, with a primary particle size of 12nm, was fluidized using nitrogen in a glass vessel of 46mm square cross-section. The superficial gas velocities at which laser-based planar imaging experiments were performed ranged from about 4–8 times the minimum fluidization velocity. Aggregates of nano-sized particles were recorded using in situ planar laser-sheet illumination with a high-resolution digital CCD camera. The aggregates were found to have a wide size distribution and contain a significant component of very small sizes. The mean size of the aggregates was found to decrease with increasing superficial gas velocity, while the mean sphericity of the aggregates was found to be insensitive to changes in the superficial gas velocity. The measurements based on planar laser-sheet imaging are compared with the results of previous studies and to predictions of existing models.