Patent GB-880006-A (GB)
Title: Distillation apparatus
Inventor: WATT PETER RIDGWAY
IPC: B01D3/12
Filed: 1957-11-19
Abstract: <PICT:0880006/III/1> <PICT:0880006/III/2> <PICT:0880006/III/3> <PICT:0880006/III/4> A distillation apparatus of particular use in the high vacuum or molecular fractional distillation of heat-sensitive materials comprises (Fig. 1) a rotatable evaporator surface 10 symmetrical about its axis of rotation and surrounding a condenser surface 16 having at least two sections 17 in the direction of the axis of rotation of the evaporator surface 10, the axis of rotation being inclined to the horizontal so as to cause distillation residue to travel toward the lower end of the evaporator surface and each section 17 of the condenser surface delivering distillate condensed thereon to the region of evaporator surface adjacent the next higher section of the condenser surface, whereby the distillate is evaporated at least twice and travels toward the higher end of the evaporator surface.  In Fig. 1, the evaporator 10, which is rotated by a driven shaft 12a, surrounds an aluminium condenser block 16 composed of water-cooled cones 17, each cone carrying a metal tongue 18 so arranged that, when distilland is introduced into bulb 14, vacuum being applied via neck 19a and heat by an infra-red emitter 20, the thin film of distilland inside bulb 14 is distilled on to the first condenser cone 17, the distillate being passed to the next higher section of evaporator surface by the corresponding metal tongue 18, the distillate again evaporating and passing eventually via other tongues 18 to a delivery section 17a, whence it is passed down tongue 18a into one of a plurality of tubes 22 rotatably mounted in a collector 24. Residual heavy fractions pass countercurrent towards bulb 14.  In a modification of Fig. 1 (Fig. 2, not shown), the tongues 18 may have wiper blades at their ends which lie parallel and in capillary contact with the inner surface of the evaporator 10, these blades facilitating spreading the distillate in bands around the rotating evaporator surface.  In this modification also, electrical heating is supplied by separate coils of wire around bulb 14 and evaporator surface 10, both the coils and a cylindrical reflector surrounding them being supported between the evaporator surface and casing 19.  In another modification adapted for continuous operation (Fig. 3, not shown), the evaporator is a cylindrical tube open at both ends and rotated by means of a drive shaft situated outside the tube.  Other forms of condenser are shown in Figs. 6, 7 and 10.  In Fig. 6 a right cylindrical condenser 170 of aluminium alloy, drilled axially for water inlet and outlet pipes 172, 172, is divided by annular ribs 175 into sections 176, the undersides of each rib and section being removed to produce part conical surfaces 178.  In Fig. 7 a condenser section consists of a truncated cone of open tubular construction made up of closed loops 180, 182 provided with water inlet and outlet 181, 183, the loops being joined by a plurality of straight tubes 184.  Several such sections can be joined by their inlets and outlets.  In a modification of Fig. 7 (Fig. 8, not shown), parts 180, 182 are each made up of two rings of channel form so constructed that one ring of each pair belongs to each section, the sections being joined by bolting abutting flanges on each pair of rings.  In Fig. 10 the condenser block is cylindrical and its outside surface 210 is divided into two or more sections by means of a wide distillate gutter 219 secured to an annular plate 217 screwed to the condenser block. Arcuate walls 220 are welded to the gutter 219 and partition off the space between it and the condenser surface.  Tubes 221 lead off distillate to the evaporator surface.  The arcuate walls 220 may be replaced by fully annular members, thereby dividing the whole surface of the condenser block into sections.