Extraction reciprocating-plate column

The nonuniformity of drop dispersions can often be important in extraction. This nonuniformity can lead to axial variation of holdup in a column even though the flow rates and other conditions are held constant. For example, there is a tendency for the smallest drops to remain in a column longer than the larger ones, and thereby to accumulate and lead to a locali2ed increase in holdup. This phenomenon has been studied in reciprocating-plate columns (74). In the process of drop breakup, extremely small secondary drops are often formed (64). These drops, which may be only a few micrometers in diameter, can become entrained in the continuous phase when leaving the contactor. Entrainment can occur weU below the flooding point. 

Fractional extraction has been used in many processes for the purification and isolation of antibiotics from antibiotic complexes or isomers. A 2-propanol—chloroform mixture and an aqueous disodium phosphate buffet solution are the solvents (243). A reciprocating-plate column is employed for the extraction process (154). 

In 1935, Van Dijck proposed that the extraction efficiency of a perforated-plate column could be improved by either pulsing the liquid contents of the column or by reciprocating the plates. The latter idea was relatively little exploited until the late 1950s, when Karr reported data on a 3-in.-diameter, open-type, perforated reciprocating-plate column. The column was further developed by Karr and Lo by employing baffles. 

Baird, M. H. I., N. V. Rama Rao, J. Prochazka, and H. Sovova, Reciprocating-Plate Columns, in Godfrey, J. C. and M. J. Slater (Eds.), Liquid-Liquid Extraction Equipment, Wiley, Chichester, England, 1994, Chap. 11. 

For stirred tanks with hold-ups up to 0.35 the constant K = 0.024 ( 1For reciprocating-plate extraction columns K = 0.I8, while for pulsed perforated-plate columns AT = 0.18 Kirk-Othmer Encyclopedia of Technology, 1978-1984). 

A.E. Karr, Design scale up and application of the reciprocating plate extraction column, Sep. Sci. Technol. 15, 877-905 (1980). 

Karr, A., Lo, T.C., Scaleup of Large Diameter Reciprocating-Plate Extraction Columns, Chem. Eng. Progr., 72, 11, 68,1976. 

The (HETS) for reciprocating plate extraction columns has been correlated [69] using... 

Karr, A. E., and T. C. Lo, Performance and Scale-up of a Reciprocating Plate Extraction Column, Proceedings of International Solvent Extraction Conference, Vol. 1, 299-320 (1971). 

Smith, K. H., T. Bowser, and G. W. Stevens, Performance and Scale-up of Karr Reciprocating Plate Extraction Columns, Ind. Eng. Chem. Research, 47, 8368 (2008). 

---