Rotating-Impeller Columns

Rotating-Impeller Columns A number of different rotating-impeller column extractors have been proposed and built over the years. Only the Scheibel and Kiihni designs are reviewed here. For information about the Oldshue-Rushton design, see the previous edition of this handbook. Also see Oldshue, Chap. 13.4 in Handbook of... 

The evaluation of acetaldehyde oxidation process was carried out by aeration of acetaldehyde solution and analyzing the concentration of acetic acid using gas chromatography HP 5890 with detector FID equipped with PEG Column in 15 minutes time interval. The gas flow rate Qg), impeller rotation speed N) and temperature (7) were varied. 

The pressure developed by a centrifugal pump depends on the fluid density, the diameter of the pump impeller, the rotational speed of the impeller, and the volumetric flow rate through the pump (centrifugal pumps are not recommended for highly viscous fluids, so viscosity is not commonly an important variable). Furthermore, the pressure developed by the pump is commonly expressed as the pump head, which is the height of a column of the fluid in the pump that exerts the same pressure as the pump pressure. 

Repeat Example 24-2 for the xylene (B) oxidation reaction carried out in an agitated tank reactor (instead of a bubble-column reactor). Use the data given in Example 24-2 as required, but assume the diameter D is unknown. Additional data are the power input without any gas flow is 8.5 kW the impeller rotates at 2.5 Hz the height and diameter of the tank are the same (h = D) the impeller diameter is DI3, and the impeller contains 6 blades assume ubr = 1.25usg. In addition to the vessel dimensions for the conversion specified (/B = 0.16), determine the power input to the agitator (P,). 

The RE process proceeds in three major types of equipment mixer-settler systems, column extractors, and centrifugal extractors. Countercurrent column extractors can be further subdivided into nonagitated nonproprietary columns and agitated proprietary extractors. Agitating the liquid-liquid system breaks up droplets and increases the interfacial area to improve the mass transfer and column efficiency. Various forms of energy input are used, e.g., rotation of propellers, impellers, and discs pulsation, vibration, and ultrasonic devices and centrifugal devices. 

Flower [25], Panda et al. [26], Doran [27]. and Payne et al. [28]. Several kinds of bioreactors, such as the stirred tank bioreactor with hollow paddle and flat blade impellers, the bubble column, the airlift bioreactor with internal and external loops, the rotating drum bioreactor, the stirred-tank with a draft tube, and the mist bioreactor have been attempted for plant cell, tissue and organ cultures (Fig. 1). 

Figure 18. Different types of bioreactors for plant cells, tissues and organs. (A) Shake Flask. (B) Aeration-Agitation. (C) Percolated Impeller. (D) Draught Tube Air-lift. (E) Draft Tube with Kaplan Turbine. -Air-liftloop. (Gj Rotating Drum. (7/1 Light Emitting Draught Tube. (I) Spin Filter. (J) Bubble Column. (K) Aeration. (L) Gaseous Phase.

Karr Reciprocating Plate Tower Up to this point, the agitated columns presented have all imparted their energy to the fluids by means of rotating elements (discs or impellers). However, there is another class of agitated columns which impart their enerQ by means of reciprocating plates or pulsing of the liquids. This results in a more uniform drop-size distribution due to the fact that the shear forces are more uniform over the entire cross section of the column. 

Plate columns gas is redispersed and disengaged at each plate up the column Mechanically agitated vessels in which an impeller rotates in a tank (usually baffled) to give enhanced rates of mass transfer ... 

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