CHARACTERIZATION OF AGITATION ENVIRONMENTS IN 250 ML SPINNER VESSEL, 3 L, AND 20 L REACTOR VESSELS USED FOR ANIMAL-CELL MICROCARRIER CULTURE

Three dimensional particle tracking velocimetry (3-D PTV) was used to characterize the flow fields in the impeller region of three microcarr ier reactor vessels. Three typical cell culture bioreactors were chose n: 250 mi small-scale spinner vessels, 3 L bench-scale reactor, and 20 L medium-scale reactor. Conditions studied correspond to the actual o perating conditions in industrial setting and were determined based on the current scale-up paradigm: the Kolmogorov eddy length criterion. In this paper we present characterization of hydrodynamics on the basi s of flow structures produced because of agitation. Flow structures we re determined from 3-D mean velocity results obtained using 3-D PTV. A lthough the impellers used in 3 L and 20 L reactors were almost identi cal, the flow structures produced in the two reactors differed conside rably. Results indicate that near geometric scale up does not necessar ily amount to scale-up of flow patterns and indicates that intensity a s well as distribution of energy may vary considerably during such a s cale-up.