GB765743A - Improvements in or relating to molecular distillation apparatus - Google Patents

Abstract

In a high-vacuum centrifugal still, the distilling surface comprises a frusto-conical rotor 32 which is supported at its apex and driven from the top of the still by a shaft 31 which connects the rotor to electric motor 29. The condenser 48 is disposed close to this distilling surface. The distilland is fed to the rotor through pipe 43; splash plate 41 and rim 42 ensuring that the liquid passes evenly over the inner surface. The liquid spreads over the rotating surface in the form of a thin film. A bank of three electric heaters 45, connected to a source of current by leads 46, <PICT:0765743/III/1> is supported close to the outer surface of the rotor. A heat reflector, comprising a cylinder 47 of polished sheet aluminium or stainless steel, surrounds the heaters. The still is evacuated through pump-manifold 21, which is provided with a refrigerable baffle 22. The condenser, which is water-cooled, consists of upper and lower annular pipes 48a and 48b joined by about sixty vertical pipes; and is arranged to operate as three separate condensing zones. The upper and middle zones are each provided with an annular series of ducts 49 for directing the two distillates into separate gutters 50. A similar gutter is mounted beneath the lower end of the condenser and serves to collect distillate condensed on the lower zone. Each of the gutters 50 is provided with a distillate take-off pipe 51. The lower edge of the rotor is located in residue-gutter 52, which is drained by take-off pipe 53.