MASS-TRANSFER IN BEDS OF MODERN, HIGH-EFFICIENCY RANDOM PACKINGS

A new model has been developed for the prediction and correlation of m ass-transfer rates in distillation columns containing random packings. Emphasis is placed on the characteristics of the newer ''high-efficie ncy'' random packings: IMTP, CMR, Fleximax, and Nutter. These packings are of the high void fraction, through-flow type and have become quit e popular for new designs as well as for retrofits. In building the mo del use has been made of a large bank of experimental data from the la boratories of Fractionation Research, Inc., and the Separations Resear ch Program (SRP) at The University of Texas at Austin. The model is ba sed on an earlier SRP study of liquid holdup and gas pressure drop in beds of random or structured packing (Stichlmair et al. Gas Sep. Purif . 1989, 3, 19]. The only packing parameter needed is a ''packing chara cteristic'' which has a value of about 0.030 for a 2-in. Pall and Rasc hig rings and about 0.050 for the 2-in. nominal size of the high-effic iency packings listed above. The model was found to fit 95% of 326 exp erimental values of height equivalent to a theoretical plate (HETP) to within +/-25% and all values within +/-30%.