Distillation apparatus

Abstract

A spiral double-tube structure including an inner tube for introducing a solvent vapor resulting from vaporization within a distillation still and an outer tube which a coolant gas cooled by an outdoor machine is passed through is disposed in a buffer tank; the solvent vapor is directly cooled from the surrounding area by the coolant gas with a large temperature difference and thus condensed into a liquid state; by means of an ejector, the liquid is mixed with the solvent suctioned from the buffer tank and returned into the buffer tank; since the solvent in the buffer tank is also directly cooled by the coolant gas, the cooling efficiency is high; accordingly, both the solvent vapor generated from the distillation still and the solvent in the buffer tank for reducing the pressure inside the distillation still can be efficiently cooled without using cooling water, and downsizing of the apparatus can also be attained.