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The power required for agitation of non-aerated medium in fermentation is ________ kW.
Operating conditions are as follows :
Fermentor diameter = 3 m
Number of impellers = 1
Mixing speed = 300 rpm
Diameter of the Rushton turbine = 1 m
Viscosity of the broth = 0.001 Pa.s
Density of the broth = 1000 kg.m–3
Power number = 5
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- 125
- 225
- 625
- 729
Correct Option: C
| Np = | ||
| Sn3D5 |
∴ P = Np Sn3D5
| = 5 × 1000 × |  |  | 3 | × 15 = 625000 W | |
| 60 |
P = 625 kW
Where ,
Np = Power No. = 5
P = Power required
S = Density 1000 kg/m3
| n = Speed in Hz = | = 5 Hz | |
| 60 |
D = Diameter of turbine = 1 m
