GB1434617A - Distillation apparatus for trace analysis - Google Patents

Abstract

1434617 Determination of distillation residue COMITATO NAZIONALE PER L'ENERGIA NUCLEARE 23 May 1973 [25 May 1972] 24584/73 Heading G1B [Also in Division B1] Apparatus for distilling under vacuum a liquid substance, for example sodium to determine any (e.g. oxide) impurities left in the residue comprises a vacuum-tight vessel 1 containing horizontal crucible plate 15 rotatable by means 22 outside the vessel, and having a plurality of cavities (54) in its upper surface to act as crucibles for samples to be distilled, heating plate 14 having electrical heating elements (50) controllable by a thermostat device, plate 14 engaging crucible plate 15 over the whole of its bottom surface, a sample feeding system comprising metering pump 38 and spout 9, 9<SP>1</SP> and means for introducing the spout into the distillation chamber and for withdrawing it therefrom, vacuumtight gate valve 7 between the distillation chamber 1 and the sample feed system, duct 40<SP>1</SP> having 40<SP>11</SP> for allowing flow of inert gas into the distillation chamber and into the sample feeding system when these are in communication and a condenser 35 Fig. 4, (not shown), removably mounted on hollow support disc 31 which has inlet and discharge lines 23, 24 for liquid coolant, the condenser and the support disc being located over the crucible plate 15 within the distillation chamber. Vessel 1, spout 9 and drain tank 11 may have external heating elements 42, 73, 42<SP>1</SP> as shown, and O rings (44) sealing shaft 12 in bushing 43 Fig. 2, (not shown) may be cooled by refrigeration fluid flowing through connections 16 and 17. In use of the apparatus, chamber 1 is isolated by closing all valves, and evacuated, and heating elements 42, 73, 42<SP>1</SP> are energized to degas the apparatus. The heating plate 14 is then heated to a predetermined temperature and reducing gas introduced via valve 27 to clean the crucible plate. Spout 9 is cleaned by temporarily actuating pump 38 to allow a flow of metal through the spout and to drain tank 11. After the cleaning operations, spout 9 is introduced into vessel 1 and the crucibles filled in turn with metal by rotation of crucible plate 15 by means of hand wheel 22. When distillation is complete, the heating elements 42, 73 are de-energized, and when the apparatus has cooled, bottom plate 2 is lowered together with components 12, 13, 14, 15 to allow removal of crucible plate 15 for analysis of solutions of the contents by for example photometry or acidimetry.