Experimental investigation of cluster properties in dense gas-solid fluidized beds of different diameters

The local solid flow structure of a bubbling fluidized bed of sand particles was investigated in three different columns to characterize the properties of clusters. The experiments were performed using a reflective optical fiber probe. The variations in size, velocity, and void fraction of the clusters due to changes in the superficial gas velocity, particle size, and radial positions were studied. The results indicate that the velocity of the clusters remained unchanged while their size increased as the column diameter increased. In addition, the radial profile of the clusters' velocity did not depend on the radial position. The results indicate that larger particles form larger clusters, which move slower. (C) 2014 Published by Elsevier B.V. on behalf of Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences.