PARTICLE-VELOCITY PROFILES AND SOLID FLOW PATTERNS IN SPOUTED BEDS

A fibre optic probe system was used to measure the profiles of vertica l particle velocities in the spout and the fountain of a half-column a nd a full-column spouted bed. In addition, a fibre optic image probe w as employed to measure vertical particle velocity profiles in the annu lus of the full-column. In the spout, radial profiles of vertical part icle velocities were of near Gaussian distribution. Particle velocitie s along the spout axis in the half-column were 30% lower than in the f ull-column under identical operating conditions. In the half column, p article velocities adjacent to the front plate were approximately 24% lower than a few millimeters away. The fountain core expanded suddenly near the bed surface and then gradually contracted with height. The m odel of Grace and Mathur (1978) gave good predictions of fountain heig hts for the full-column. In the annulus region, there was a 28% differ ence between particle velocities adjacent to the column wall and those only 2 mm away. The integrated upward solids mass flow in the spout a nd the downward solids flow in the annulus matched well at different b ed levels.