GB997618A - Process and apparatus for the quantitative distillative analysis of a component of aliquid mixture - Google Patents

Abstract

997,618. Analysing liquids by distillation. HEINRICH FRINGS G.m.b.H. Oct. 31, 1963, No. 43105/63. Headings B1B and B1X. The amount of a liquid component in a liquid mixture may be determined by measuring the difference in boiling points between the liquid mixture with and without the selected component. In one embodiment of the apparatus of the invention (Fig. 1), the liquid mixture is supplied to boiling vessels 1 and 2 from container 23 through conduits 24 and 21. Each boiling vessel has a heater 7 and an inner vessel 11 and 12 which surround thermocouples 13, 15, 14 and 16 which are connected in series in that order to an amplifier 17 and indicating instrument 20. The function of vessels 11 and 12 is to prevent overheating. Boiling vessel 1 has a condenser 3 above it which is provided with two condensing surfaces, one for that liquid boiling within the inner vessel 11 and the other for the liquid boiling in vessel 1. The vessel 2 has a fractionating column 4 above it together with a condenser 6 and fraction divider 5 whilst the water flow to both condensers 3 and 6 is regulated by valve 33 through conduit 32. A reading is taken on instrument 20 once the boiling temperature in vessel 12 is constant. An embodiment of the apparatus for continuous analysis, Fig. 2 (not shown), has a pumping device which supplies the liquid mixture at a controlled rate, separately to vessel 1 and also to the fractionating column 4 at such a position that the liquid component under analysis is distilled off and none reaches the vessel 2. Both vessels 1 and 2 are equipped with overflow devices, whilst the indicator 20 is replaced by an automatic line recorder. In another embodiment, Fig. 3 (not shown), continuous analysis is effected as above, but the liquid mixture flows at a controlled rate serially through vessel 1 and then on to the fractionating column 4. Continuous analysis may also be carried out in another embodiment, Fig. 4 (not shown), which is similar to apparatus immediately above, but has a heated liquid mixture supply and the provision of 4-point thermocouples situated in the vapour zone above each boiling liquid. The temperature difference in this case is recorded on a device for measuring small voltages, i.e. a compensograph, while the reflux divider is constituted by a small open-topped vessel which has ports both to the inside of the condenser and the distillate discharge. A fully automatic apparatus may also be used. Examples of the invention refer to the determination of (a) ethanol in fermenting beer ; (b) acetone in water ; (c) ethanol in vinegar, and (d) ethyl acetate in acetic acid. Other mixtures which can be determined may contain methanol, propanol, methylpropyl ketone, acetone, acetic acid, benzene, toluene, xylene, chloroform, ethyl acetate and water. The analysis of a liquid mixture having more than two components is also mentioned.