Patent GB-638348-A (GB)
Title: Distilling process and apparatus
IPC: B01D3/00
Filed: 1946-04-04
Abstract: <PICT:0638348/III/1> <PICT:0638348/III/2> <PICT:0638348/III/3> In a process for the separation of binary liquids into their components by exhaustion of the liquid of its more volatile component, of the kind in which the liquid is flowed downwardly through a plurality of calandria-type columns in countercurrent to an upwardly flowing vapour, e.g. steam or vapours produced in the process, the vapours withdrawn from each column are used, except in the first column, to heat the calandria of the preceding column and the condensate thus formed is injected into the liquid passing down the column from which the vapours forming the condensate were withdrawn.  As shown in Fig. 1 and applied to the recovery of alcohol from wines, two exhaustion columns 1, 3 are employed in conjunction with a further distillation column 48 for further rectification of the alcohol.  Each of these columns has an annular rectification column or columns, viz. 2, 4, 50, 51, associated therewith wherein the vapours obtained from the exhaustion columns are rectified by contact with the crude or partly exhausted wines prior to reinjection into their respective columns. The wine is fed by line 16 through a recuperator 15 where it is preheated by the exhausted lees leaving column 1 through line 14. The heated wine passes through tube 18 in part through line 22 for injection through valves 23 into the rectifier 2 and in part through line 21 to a dome 24 on the top of the exhaustion column 3, and flows down through the tubes thereof in countercurrent to vapours injected through nozzles 28.  The partly exhausted wine is removed through tube 27 and together with reflux from column 2, supplied through line 10, is injected through line 8 into the dome 6 of column 1 down the tubes of which it flows similarly as in column 3 leaving at the base as fully exhausted lees through line 14.  The tubes of the exhauster 1 are externally heated by steam admitted at 5 and the downwardly-flowing wine in the tubes is directly heated by a countercurrent of steam admitted through line 12 to nozzles 13. Similarly, the tubes of rectifier 3 are heated externally by vapours supplied through line 33 from unit 2 and internally by vapours injected through nozzles 28 supplied through line 75.  This method of heating is described in Specification 507,435.  The vapours evolved in the tubes of the units 1, 3 are collected in the domes 6, 24 and pass downwardly through annular passageways 7, 25 to the base of units 1, 3 and then flow upwardly through the nested rectifying units 2, 4, where they are rectified by liquid wine injected through valved nozzles 23, 32, 32a, the crude wine being injected through nozzles 23, while condensate from rectifier 48, collected in separator 55, is injected through the nozzles 32 and condensate from the exhauster 3, collected in separator 30, is injected through the nozzles 32a. Liquid collecting at the base of column 21 is removed through line 19 and pumped by pump 20 into line 21 where it mixes with the crude wine flowing into dome 24.  The alcoholic vapour from unit 4 passes through line 37 to a rectifying condenser 38 where two fractions are collected, the less concentrated fraction being withdrawn through line 41 and controller 41a and fed through line 43 to valves 42 for injection into rectifier 50 of the upper distillation unit while the more concentrated fraction is withdrawn through line 43 and regulator 43a and fed through lines 43, 45 to the dome 24 of the upper unit. This column is similarly constructed and operated as the lower units except that it is provided with two nested rectifiers 50, 51 from the latter of which the concentrated alcohol is recovered through line 57 and passed to condenser 58 from which fractions of higher and lower concentration are recovered to tanks 65, 61 where they are further concentrated by auto-distillation under reduced pressure produced by the pump 68.  The fraction collected in tank 65 is removed for use while the fraction collected in tank 61 is fed back to rectifier 51 through valved lines 62.  In Figs. 2 and 3 (not shown) the exhausting unit is divided into three columns and the enrichment unit has two rectifying columns in one of which a salt solution (e.g. calcium chloride, sodium acetate, potassium or sodium carbonates, sodium nitrate) is employed in known manner to dehydrate the alcohol.  The nested exhaustion-distillation - rectification units are shown in detail in Figs. 4 and 8, Fig. 4 showing in section details of the inner column 3 of Fig. 8. Column 3 comprises a tubular calandria through the tubes 76 of which flow the liquid to be exhausted in counter-current to steam of vapour injected upwardly by nozzles 82. The tubes 76 are divided into groups by diaphragm 88, Fig. 6.  The liquid is supplied through a tube 8 and funnel 79 to the tubes 76. The vapours formed rise through helical passages formed between a wall 24 and helix 80 which forms a centrifugal separator for entrained liquid and pass thence to an annular passage 25 formed between the walls 24, 24b of the dome, this passage continuing to the bottom of the rectifying unit 4.  The tubes 76 may be divided medially into upper and lower sections connected by a chamber to which liquid of alcoholic strength equivalent to that of the liquid in the tubes is supplied (Fig. 12, not shown).  The vapours flow upwardly in a helical course through the passage formed between the walls and a helix 871.  The rectifying liquid entering through valved passages 32 passes into drain channels 89 running co-extensively with the helix 871.  The column 3 is preferably arranged excentrically in respect to the column 4. The tank 65, Fig. 13, for auto-distillation of the concentrated alcohol contains a second cylindrical vessel 122 having a heating serpentine 123 over which the alcohol entering at 59 flows upwardly, being directed by the aperture 124 against a cone-shaped baffle 125a which throws the drops back on to a perforated plate 125.  The rectifying condenser 38 is shown in Fig. 11 and <PICT:0638348/III/4> <PICT:0638348/III/5> <PICT:0638348/III/6> comprises conical inner and outer heat exchanger sections formed respectively by (1) the outer cylindrical wall 38 and the outer surface of the conical wall 107 and (2) the inner surface of the wall 107 and overlapping cylinders 98, 99; helices 108 and 100, 103 give a centrifugal motion to the upwardly-flowing vapours. Vapours are supplied to the inner vessel through tube 37 while condensate from the exhaustion unit is collected in vessel 111 and fed through tube 39 to the base of the outer section.  Condensate is collected in ducts 101, 104, draining through tubes 105, 106, to an annular space between the cylinders 98, 99 and thence through tube 41.  Automatic level control of the liquid in the regulators 43a, 41a for withdrawal of condensate from the various rectifiers is obtained by valve apparatus with electrically-operated servomotor control (see Group XXXV).