Patent GB-623224-A (GB)
Title: Improvements in or relating to the manufacture of soap
IPC: C11D13/04
Filed: 1947-01-20
Abstract: <PICT:0623224/III/1> <PICT:0623224/III/2> <PICT:0623224/III/3> Nigre and molten neat soap are continuously separated from molten fitted soap by forming a continuous, substantially quiescent stream of molten fitted soap so as to allow the nigre to separate out by gravity and withdrawing settled neat soap.  The molten fitted soap may be supplied from a continuous stream of molten washed soap which is fitted by continuous agitation with streams of brine, caustic alkali and water as required.  As shown, a small receiving vessel 45 (Fig. 1) is fed with washed soap from the pipe 46 fitted with a valve 47.  Brine, caustic liquor and water are supplied through the pipes 48, 49 and 50 provided with the valves 51, 52 and 53 which may be connected to automatic flow rate control devices.  The level of the <PICT:0623224/III/4> <PICT:0623224/III/5> <PICT:0623224/III/6> ingredients in the vessel 45 is governed by the ball valve 54 controlling the aperture of the valve 55 in the run-off pipe 56. The ball valve may also control the steam valve 59 of the steam injector 57 by means of which the mixture of washed soap and electrolyte is agitated (Fig. 2).  The mixture may be supplied from the pipe 56 into the steam injector 57 fed by a steam pipe 58 and the ingredients of the "fit" may be intimately mixed by the injector and discharged into the closed vessel 61.  They are further agitated and mixed at the boiling point in this vessel by their turbulent passage to the top of the vessel 61 and over the baffles 62 and 63 before being discharged through pipe 64 to the settling apparatus.  The molten washed soap may be obtained from a continuous washing process such as that disclosed in Specification 612,014.  In an example, the molten fitted soap is conducted in a continuous stream to feed tank 21 (Figs. 4 and 7), the valves 9 of the lead-off pipes 8 from the six settling trays 1 (Figs. 4, 5 and 7) being closed.  The valves 11 in the lead-off pipes 10 are also closed and the valve 14 opened to the branch pipe 12 (Fig. 4).  When the tank 21 is full, the molten fitted soap flows over the weir 24 down the shoot 25 into the funnels 19 p  (Figs. 4 and 7).  The arrangement of funnels 19, stems 20, manifolds 16 and 18, pipes 15 and 17, and distributing troughs 4 serves to provide an even distribution of molten fitted soap both between the six trays and between the four compartments 2 within each tray (Fig. 5).  The molten fitted soap enters each tray 1 through the distributing troughs 4, fills up the spaces between the weirs 5 (Figs. 4 and 5) and the nearest end walls of the tray, flows over the weir 5, and flows horizontally in a quiescent manner within the main body of the tray towards the weirs 27 (Figs. 4, 5 and 6) at the shallow end of the trays.  Nigre separates out under gravity from the molten fitted soap to form lower layers, while molten neat soap remains as layers on the surface.  The molten neat soap flows over the weirs 27 and out of the trays into the shoots 29.  The nigre which settles out runs counter-current to the flow of soap along the sloping bottom of the trays towards the deep end of the latter whenever the valves 11 are opened, and is prevented by the weirs 5 from mingling with the incoming flows of molten fitted soap.  The valves 11 may be opened periodically either by hand or automatically by mechanical means. When the trays are full and the weirs 27 submerged, the sluice gates 30 at the shallow ends of the trays are raised, permitting the molten neat soap to flow out of the trays through the spouts 31, funnels 32 and draining pipe 33.  The sluice gates 30 may be adjusted to narrow the effective lengths of the weirs, thereby increasing the depth of molten neat soap flowing over the weirs.  This minimizes any drag which may be caused by a viscous skin formed on the liquid surface of the soap by local cooling as it flows out of the trays.  The preferred long and narrow shape of the troughs or compartments of the trays obtained by the provision of the partitions 3 also assists in increasing the depth of soap flowing over the weirs 27.  The arrangement of trays may be completely enclosed and the trays lagged to prevent cooling of the surface of the liquid in each tray.  To empty the apparatus, after withdrawing any bottom layer of nigre in the trays through pipe 12 (Fig. 4), the contents of feed tank 21 (Figs. 4 and 7) are discharged into the top trough 4 by opening the sluice gate 26 and the spaces between the weirs 5 and the near end wall of each tray are emptied by opening the valves 9.  Valve 14 is then opened to branch pipe 13 and the contents of the troughs are allowed to drain through the draining pipe 7 and branch pipe 13. Illustrated examples are also given of settling apparatus comprising a vertical series of narrowly-spaced slightly-inclining shelves in which the flow of the quiescent stream of molten fitted soap is slightly upward, and of a modification of an ordinary soap boiling pan, utilizing the bottom as a shallow separating tray. Specifications 549,386, 549,387, and 573,787 also are referred to.