EVALUATION OF THE HYDRODYNAMIC REGIME OF AEROBIC STIRRED BIOREACTORS USING THE MIXING DISTRIBUTION CRITERIA. SUSPENSIONS OF PENICILLIUM CHRYSOGENUM PELLETS
STEFANICA CAMARUT 1, ANCA-IRINA GALACTION 2, DAN CASCAVAL 1* (1)TECHNICAL UNIVERSITY "GH. ASACHI" OF IAŞI, FACULTY OF CHEMICAL ENGINEERING, DEPT. OF BIOCHEMICAL ENGINEERING, D. MANGERON 71, 700050 IAŞI, ROMANIA (2)UNIVERSITY OF MEDICINE AND PHARMACY “GR.T. POPA” OF IAŞI, FACULTY OF MEDICAL BIOENGINEERING,
The study on mixing distribution for an aerobic stirred bioreactor and P. chrysogenum pellets broths indicated the significant variation of mixing time on the bioreactor height. The uniform mixing in whole bulk of fermentation broth can be reached only for 500 rpm and biomass concentration below 24 g/L d.w. The influence of aeration rate has to be correlated with the fungus concentration. At lower biomass concentration, below 16 g/L d.w., due to the appearance of flooding, the mixing time initially increased with the increase of aeration rate, reached a maximum value, decreasing then (the critical air flow rate varied with the position of pH electrode into the broth and fungus concentration, being of 150 - 300 L/h). For higher P. chrysogenum concentration, the increase of air flow rate lead to the continuous mixing intensification for all the considered positions into the fungus broth.
