GB798072A - High vacuum distillation apparatus - Google Patents

Abstract

<PICT:0798072/III/1> <PICT:0798072/III/2> In a high-vacuum distlllation apparatus, particularly for molecular distillation, comprising a vacuum chamber 1 having a rotatably mounted shaft 8 carrying discs 12a, 12b and 12c which are heated to different temperatures as described below, which partly dip into the distilland and the side walls of which form vaporizing surfaces, and having condensers 22, 23, 24 and 25, there are provided a pair of drip troughs (e.g. 30 and 31) under at least one of the condensers, which collect separately the distillates flowing off the opposite side walls of such condenser, and separate discharge pipes (e.g. 35 and 36) for the distillate collected in the two drip troughs of the (or each) pair. The distilland is introduced by pipe 5 and flows through the chamber and out through exit 21. Preferably the sump is divided into distinct compartments by weirs 44 and by partition walls 45 associated with each disc. The discs are heated by passage of a liquid heated in the container 15 then pumped along tube 13 inside the shaft 8. The liquid passes through holes 18 into the shaft, flows through each disc in the order 12c to 12a being deflected by baffles 19 and is returned by tube 20 to the container 15. In operation the chamber 1 is evacuated by suction applied through tube 3. The shaft 8 is rotated and the discs assisted by the cups 43 lift films of liquid which evaporates due to the heat of the discs, the vapours condense on the condensers and the condensates are separately collected in the collectors 40a, 40b, 40c, 40d, 40e and 40f. If perforated baffles are used in the discs then both sides of each disc will be heated to the same temperature and the condensates collected from either side of any one disc (e.g. in collecting troughs 31 and 32) may be connected to a common discharge pipe and collected together. Specification 667,285 is referred to.