ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
This investigation is a study of the effect of flow rates and packing size and column diameter upon the holdup of a toluene dispersed phase, flowing countercurrent to a continuous water phase in packed liquid-liquid extraction columns. Six different packings were used: ¼-, ⅜-, ½-, ⅝-, ¾-, and 1-in. nonporous, unglazed-porcelain Rasching rings. Three extraction columns, 3, 4, and 6 in. I. D., were used in the experimental work.Three types of dispersed-phase holdup, free, operational, and total, have been investigated. An empirical correlation is presented for the total holdup data below the loading point. A correlation of the effect of packing size on the exponential term r and the coefficient A1 is developed for packing sizes 1/2 in. or larger when the column-diameter-to-packing-size ratio is at least 8 to 1. The term A1(VD)r in the equation accounts for at least 90% of the total holdup. The small magnitude of the residual term B1(VD) (VC8) did not permit a definite correlation of the coefficient B1 or the exponent s.Observation of the dispersed-phase holdup during column operation revealed a transitional behavior of the 3/8-in. rings as compared with that of the 1/4- and 1/2-in. or larger packing. Two, and sometimes three, regimes of flow occur in packed extraction columns. the increase in holdup with increasing continuous-phase flow rate differed for each zone. In the two zones below the loading zone the holdup was found to increase linearly with the dispersed-phase flow rate for a constant continuous-phase flow rate. A new method of randomly packing an extraction column has been found to give reproducible holdup data.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690010408
