Gassed Agitated Vessels, Nonboiling

1 Single Impellers. The well-known equation for impeller power is often modified for gas-liquid systems to give 

For all down-pumping PBT impellers, the RPD lines cross over and do not follow the orderly progression found with radial flow turbines. General sensitivity to the geometry of down-pumping two-phase hydrodynamics, particularly with respect to the transition between direct and indirect loading, has discouraged the construction of flow maps for these mrbines. 

Example 11-1 Power Draw of an Agitated Reactor. A 5 vessel (177 ft or 1320 gal) has an impeller 0.52 m (1.7 ft) in diameter and an nngassed power nnmber of 5.0 driven at 42 rpm in water (density 62.4 Ib/ft and viscosity 1 cP). What is the ungassed power draw of this impeller Ans. 65.2 W.) If the gas flow nnmber is 0.04, what is the gassed power demand Ans. 55.7 W.) 

Name SI Value SI Unit U.S. Engg. Value U.S. Engg. Unit 

See Table 11-5 for the calculations. The relevant equations, which are solved using TK Solver or a similar program, are 

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