Device for achieving is thinner flue signal always basis of layers on evaporation surfaces in the case of the molecular distillation

摘要

PICT:0782073/III/1 In a high-vacuum still the distilland is spread as a film over the distilling surface by means of a scraper actuated by a magnet which is itself moved by mechanical means outside the still. Fresh surfaces of the distilland are thereby continually exposed; and any charred material is removed from the distilling surface. The latter may be in the form of a disc, a rectangular plate, or a cylindrical tube; and it may be made of aluminium, copper or brass, if necessary plated with silver, chromium or gold. The distilling surface may be heated by electricity, steam or hot liquid circulation thermostatically controlled, or by infra-red radiation. The distilland removed from the distilling surface by the scraper may, if desired, be recirculated to the distilling surface; and by raising the temperature of this surface various fractions may be obtained. The apparatus shown comprises a hollow cylindrical column 11 enclosed in an air-cooled tube 14 which is evacuated. The interior of the column, which is at atmospheric pressure, contains an electric heating element 13. The distilland is introduced through tube 17 on to the outer surface of the column. The column is surrounded by a close-fitting but freely-sliding steel ring 12 which is caused to reciprocate over the heated surface between points B and B1 by means of permanent magnet 15 which is itself reciprocated by an external mechanism. The movement of the ring over the distilling surface results in an even film being obtained. The distillate condenses on the interior of tube 14 and is collected in annular channel 18. The residue falls from the column into funnel 19 and thence passes to a receiver. A still having a horizontal plate as the distilling surface is also described. A scraper, which may have flexible strips to follow any inequalities of the plate surface, is rotated over the upper surface of the plate by means of permanent magnets which are moved by a motor.