Tracer dispersion in a laboratory air-lift reactor

Abstract Measurements of single-circulation Bodenstein numbers are reported for a laboratory concentric-tube air-lift reactor operating with air—water mixtures. The Bodenstein numbers for three different lengths of draught tubes fall with increasing gas throughput but tend to a constant value when dispersion in the gas disengagement section becomes important. The change in variance of a pulse of tracer due to its passage through the head section was measured and at high gas throughputs this region approaches well-mixedness. The variation of Bodenstein numbers is determined by mixing in the riser, the downcomer, and the head section. An existing correlation is employed to examine the contribution of each section. Measurements of the influence of additives upon tracer dispersion are reported.