A viscous pump bioreactor

The fluid dynamic design and characterization of a low mechanical stress agitator and bioreactor vessel for large‐scale bioprocessing using anchorage dependent mammalian cells is considered. The complex and fragile nature of mammalian cells puts stringent constraints on the design of agitators for stirred tank bioreactors. Traditional agitators have difficulty meeting the competing requirements of fluidization and mixing while maintaining low enough mechanical stress levels to avoid cell damage. A rotating disc agitator design is proposed. Flow visualization and laser Doppler velocimeter measurements reveal fluidization of microcarriers with a gentle (low turbulence level), highly three‐dimensional flow characterized by good mixing at low hydrodynamic shear stress levels.