A 3,000 L fermenter (1.5 m diameter) with an operating liquid volume of 2,000 L and 4 baffles will be used for a yeast fermentation. Assume one six-blade turbine impeller (0.6 m diameter) will be operated at 200 RPM and the fermenter will be aerated at 1,000 L/min. (a) Calculate the ungassed power requirement, (b) the gassed power requirement and

(c) the kLa for these conditions.

Power number (NP) vs. Reynolds Number Gassed Power (Pg) vs. Aeration Rate (Na) Ratio of power requirement for aerated vs. nonaerated systems as a function of Na : A, flat blade turbine (8 blades) B, vaned disc ( 8 vanes) C, vaned disc ( 6 vanes) D, vaned disc (16 vanes) E, vaned disc (4 vanes) F, paddle Biochemical Engineering Fundamentals, Bailey and Ollis, 1986 Na=(Q/NDi3)whereQ(e.g.m3/s)