Improvements in vacuum distillation process and apparatus

摘要

In a process of vacuum distillation, a thin film of the distilland spread centrifugally on a rotating surface within the evacuated chamber, is subjected to radiant heat, harmful contact between the distilling vapours and the source of radiant heat being prevented. This may be effected by enclosing the radiant in a transparent envelope; by allowing a controlled leak to blow the vapours away from it; by arranging baffles for the vapours; or by disposing transparent surfaces between the radiant and the film of distilland, e.g. by placing radiants outside a chamber fitted with windows or by making the condensing surface of transparent material, e.g. quartz. An auxiliary heater may also heat the vaporizing surface on which the film of distilland is spread. A radiant heater 34 with a quartz envelope, Fig. 1, heats a film of distilland on the rotating vaporizing surface 8, which is also heated by heater 14. The vapours are condensed on the cooled annular collars 24 which act as baffles. The radiant heater may further be provided with vapour baffles 110, Fig. 6, and with a controlled leak 112 to blow the vapours away from the heater. In modifications, the vaporizing and condensing surfaces both rotate in a vertical plane; radiant heaters are disposed behind a transparent condensing surface; the vaporizing surface is in the form of a rotating truncated cone with stationary baffle-type or lattice-type condensing surfaces and the radiant heater disposed within it; the vaporizing surface is a series of rotating superimposed truncated cones with a stationary radiant heater and baffle reflectors disposed in their axis and stationary condensing surfaces outside them. Specification 607,019 is referred to.