GB539056A - Vacuum distillation - Google Patents

Abstract

539,056. Film evaporators ; evaporators and condensers in structural combination. DISTILLATION PRODUCTS, Inc. May 25, 1940, No. 9243. [Class 32] In processes for the multi-stage distillation of organic liquid under high vacuum solids accumulating in the liquid and tending to foul the vaporizing surfaces are removed therefrom between each distillation stage. The solids may be removed by filtration or centrifuging. In Fig. 1 the liquid is distilled by flowing it down the outside of a cylinder 18 heated internally by a resistance 22 and placed inside an outer vessel 6 on the walls of which the vapours formed are condensed and which is evacuated by a pump connected to a pipe 8. The liquid if fed through a pipe 52 to the centre of a rotating disc 46 provided with concentric gauze cylinders 50 through which the liquid is forced by centrifugal action before reaching a flange 34 from which it flows through perforation 36 on to the wall 18. The rotating cylinder 50 may be replaced by fixed gauze filters through which the liquid flows under the action of gravity. In Fig. 3 the liquid is fed through a pipe 108 to a central recess 92 formed in a rapidly rotating plate 90 the recess being formed with re-entrant walls so that solids remain therein while the liquid is thrown outwardly by the centrifugal force over the disc which is heated by resistances 102. Unevaporated liquid is caught in an annular gutter 98 and is removed by a pipe 110. The process is applicable particularly to the short path high vacuum molecular distillation of fish oils containing fat soluble vitamins, petroleum oil, soluble oils, glycerides, drying oils, and oils containing hormones, sterols &c. Specification 482,880 is referred to.