Abstract
Ultrafine particles have an extremely large external specific surface area, strong adhesive and agglomeration forces and large bed voidage exceeding 90%. Ultrafine particles were packed by means of tapping, centrifugal and compression methods, and the axial and radial distributions of voidage in the resulting beds were measured by the X-ray computed tomography (X-ray CT) method. The results of the measurements clarified the internal structures of the packed bed of ultrafine particles obtained by the above-mentioned methods, and the internal structures of the packed beds were compared with each other. It was also found that the packing characteristics depended on the structural features of the constituent particles, such as chain-like and lumpy structures.
