GB972015A - Method and apparatus of distillation - Google Patents

Abstract

972,015. Fractionating columns; treating liquids with gases. GENERAL GAS KABUSHIKI KAISHA. May 25, 1961 [Dec. 14, 1960], No. 19020/61. Headings BIB and B1R. In operating fractionating columns of the plate type, the ratio of the height of clear liquid on each plate to the rate of vapour flow is maintained above a specified minimum value, expressed mathematically in the Specification, and the ratio of effective distance for the passage of the liquid flow on the plate to the height of the clear liquid is maintained at a value of at least 12. As shown in Figs. 5 and 6, each plate may be formed by three planes 3, 4, 5, each provided with bubble caps 9. Partition walls 6, 6a, having perforated ends 7, 7a, are disposed between the three parts of the plate. Liquid enters the plate through downcomer 1, flows over parts 3, 4 and 5 in a zig-zag path, and then flows down to the next plate through downcomer 2. The vapour leaving the head of the column is preferably heated in a compressor, and then used for heating the bottom of the column. In Figs. 9 and 10, the vapour space between adjacent plates is divided into two compartments by partition 36 ; and the plate is provided with board 35 and wall 36a. The liquid enters the plate through downcomer 31, which passes through partition 36. The liquid flows over dam 30, and flows along section 34 where it is contacted with vapour leaving bubble cap 39. The liquid passes round the other side of board 35, flows through a hole 37 in a partition 36, and then passes along another bubble cap section before leaving the plate through the upper end 32a of the next downcomer. These columns are suitable for the distillation of aqueous ethanol. The separation of xylene into its components, cyclohexane from light naphtha, and butadiene from its homologues, are mentioned.