INFLUENCE OF REACTOR GEOMETRY ON MIXING CHARACTERISTICS IN A DOWN FLOW JET LOOP BIOREACTOR - NEWTONIAN AND NON-NEWTONIAN FLUIDS

Mixing characteristics in the downcomer and the riser of a continuous down-flow jet loop bioreactor was studied with Newtonian and non-Newto nian fluids. The mixing parameters were determined through the curve f itting of the experimental impulse response data with the solution of one dimensional axial dispersion model. It was found that circulation number and axial dispersion coefficient increased with an increase in liquid flow rate and draft tube to column diameter ratio and the axial dispersion coefficient was comparatively higher in the riser. The cir culation number increased with decrease in nozzle diameter. The model predicted the experimental data well within 8% deviation for both the systems (water and CMC). Correlations were obtained to predict axial d ispersion coefficients in the riser and downcomer of the reactor.