Abstract
THE MODEL PROPOSED BY CLIFT AND GRACE TO DESCRIBE THE MOTION OF INTERACTING BUBBLES IN A FLUIDIZED BED IS EXTENDED TO APPLY TO FREELY-BUBBLING BEDS.THE MODELR REQUIRES AS A BOUNDARY CONDITION THE SIZE, POSITION AND FREQUENCY OF BUBBLES AT SOME LOW REFERENCE LEVEL IN THE BED.THE MOTION AND COALESCENCE OF BUBBLES IN THE BED IS THEN CALCULATED TO GIVE PREDICTIONS OF BUBBLE FREQUENCY, SIZE AND SPATIAL DISTRIBUTIONS AT ANY HEIGHT ABOVE THE REFERENCE LEVEL.IT IS SHOWN THAT THE PREDICTIONS AGREE CLOSELY WITH MEASUREMENTS OF THESE PARAMETERS IN TWO-DIMENSIONAL BEDS EVEN THOUGH THE MODEL REQUIRES NO FITTED PARAMETERS.(A)