Flow pattern transition in a large jetting fluidized bed with double nozzles



An experimental study was conducted in a 500 mm ID, 8,000 mm high jetting fluidized bed with double vertical nozzles using frame-by-frame analysis of experimental videos. Three different flow patterns (separated jets, flow transition, and jet coalescence), with the two jets always coalesce within the penetration depth, were first observed in the jetting fluidized bed. Radial profiles in the fluidized bed were measured with a PC-4 optical fiber probe. Effects of jet gas velocity and nozzle distance on the radial and axial voidage distribution were studied. The bed hydrodynamic behavior was characterized using a deterministic chaotic theory to analyze effects of jet gas velocity, static bed height, and nozzle distance on the correlation dimension, which increased with increasing jet gas velocity and static bed height.