DISTILLATION PERFORMANCE OF WIRE-COILED WETTED-WALL COLUMN IN THE RANGE OF LOW REFLUX RATE UNDER REDUCED PRESSURE

Abstract

Wire-coiled glass tubes were examined as wetted-wall surfaces in vacuum distillation. The performance data obtained show that these walls are advantageously of great use in the distillation of both surface tension positive and negative systems and, in addition, for where the reflux flow rate is very low. It is noted that the desired pitch lengths of coil are 1.0 cm or less for the positive system and 0.25 cm or less for the negative one, respectively, and that the diameter of the coil wire and the number of helical threads not more than 2 have practically no effect on the column performance.
The continuous capillary and wettability of liquid on the wall surface may play a major role toward the achievement of effective distillation, not only in surface tension positive system but also in negative system.