Study on energy dissipation in modified airlift bioreactor / 生物工程学报

ABSTRACT

The effects of operational variables and reactor configurations (e.g. diameter of draft tube and the number of static mixers) on energy loss in modified airlift bioreactor were investigated at the first time. The results showed that improving the structure of draft tube could reduce energy loss in the bioreactor. When the diameter of draft tube and the number of static mixers were 4.0cm and 39, respectively, the total energy loss in the modified bioreactor was the least among all the configurations and 23.6% less than that of the conventional counterpart at the same air flowrate. The energy consumption for aeration was the smallest (43.9% less than that of the conventional counterpart) when the diameter of draft tube and the number of static mixers were 5.5cm and 13, respectively. The highest energy dissipation (70% - 80%) occurred in the riser, the bottom zone (about 20%) took the second place and the separator (less than 10%) took the third place. The energy dissipation in the downcomer was neglectable under the conditions in the research. When the energy loss per unit volume was considered, bottom zone stood the first place. It was implied that the riser was the most important zone to cut down the energy loss of the bioreactor and some attention should also be paid to the bottom zone.