Baffle towers extraction rates

Refer to Fig. 15-39. The tower is formed into compartments by horizontal doughnut-shaped or annular baffles, and within each compartment agitation is provided by a rotating, centrally located, horizontal disk. Somewhat similar devices have been known for some time. The features here are that the rotating disk is smooth and flat and of a diameter less than that of the opening in the stationaiy baffles, which facihtates fabrication and apparently improves extraction rates. The typical proportions of the internals of the RDC are as follows ... 

Fig. 10.56, is the same in principle but is used in the larger diameter towers to reduce the length of travel of the liquid film on the baffle. Baffle spacing in these towers is ordinarily 4 to 6 in. The towers are versatile, capable of handling a wide variety of liquids and flow rates, and have had application in the extraction of acetic acid from pyroligneous liquors and from solutions used in cellulose acetate rayon manufacture, in the extraction of caffeine in the food industries, and for general chemical recovery in the synthetic organic chemicals industries. 

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