FLOW PATTERNS IN A PILOT PLANT-SCALE TURBULENT FLUIDIZED-BED REACTOR - CONCURRENT APPLICATION OF TRACERS AND FIBER OPTIC SENSORS

Hydrodynamics of a turbulent fluidized bed is studied by means of the concurrent application of fiber optic sensors and a helium tracer. It is observed that in the vicinity of the column wall there is a high bu bble activity region. Low bubble activity and negative bubble velociti es are reported for the dense phase near the column centre-line region . A temperature increase from 22 to 145 degrees C results in a more ho mogeneous turbulent fluidized bed with smaller bubbles and more gas fl owing through an expanded dense bed emulsion phase. Mass transfer coef ficients between bubble-emulsion (k(be)) and babble-annulus (k(ba)) ar e evaluated. The dominant mass transfer path was the one from the bubb les to the annular region with k(ba) being several times greater than k(be).