Flow field in the freeboard of vortexing fluidized bed

摘要

A systematic investigation on the flow field in a vortexing fluidized bed cold model was reported. The gas velocity profiles within the freeboard with diameters of 0.19 m and 0.29 m were measured by using a five-hole pitot tube. A new parameter, called vortex number, V_0r, defined as the ratio of tangential velocity to axial velocity of the swirling gas stream, was proposed for representing the swirl intensity. V_or is found to be increased with secondary air velocity, and decreased with primary air velocity and diameter of secondary air nozzles.