LIQUID-MIXING IN INTERNAL LOOP AIRLIFT REACTORS

Liquid mixing in the riser and downcomer of two- and three-phase inter nal loop airlift reactors as well as the overall liquid mixing were st udied. Tracer was injected into the airlift reactors, and pH sensors w ere employed to measure the variations of tracer concentration in the riser, downcomer, top, and bottom sections. The Bo number in individua l sections of the airlift reactors were obtained by time domain analys is of these concentration variations. It was found that the degree of mixing in the riser was higher than that in the downcomer. Moreover, m ixing in the two-phase system was superior to that in the three-phase system, and the degree of mixing of the calcium alginate system was lo wer than that of the polystyrene system. Minimum values of the overall axial dispersion coefficient existed in the relationship between the overall axial dispersion coefficient and solids loading.