Patent GB-670958-A (GB)
Title: Improvements relating to solvent extraction of solid materials particularly of oils,fats and waxes from organic materials
IPC: C11B1/10
Filed: 1948-07-21
Abstract: In the solvent extraction of fatty oil and wax-bearing materials in apparatus of the endless container-chain type, a plurality of re-circulations of part miscellas are circulated through successive portions of the chain of containers throughout the greater part of the cycle, the part-miscellas being discharged from the portions of the chain of containers for collection and re-circulation.  The re-circulation may be made to a single or a group of containers.  The apparatus may comprise both the vertical and horizontal types.  In the former type the series of injection nozzles 71 . . . 76 and collecting devices 91 . . . 96 associated with the vertical runs of the endless chain of containers 10 are divided into groups equal to the collecting tanks 61 . . . 66, the groups of nozzles being connected to the discharge sides of pumps 81 . . . 86 connected to the tanks to which the groups of collecting devices 91 . . . 96 <PICT:0670958/III/1> <PICT:0670958/III/2> <PICT:0670958/III/3> drain respectively.  Each of the tanks 61 . . . 65 is provided with a weir 67 so that miscella in excess of that circulated by the associated pump flows into the next tank and the last tank has an overflow 68 discharging the full miscella to storage.  Fresh solvent is supplied from a pipe 46, the containers draining before passing over the upper turn 21b where they are inverted for emptying into a trough 49 with discharge screws 50 and re-filled from a hopper 60.  The preferred form of container 10 is provided with a perforated supporting plate 25 for the material to be extracted above an unperforated plate 22 to form a drainage chamber 26 therebetween having a discharge nozzle 27. Below the plate 22 are arranged perforated spray tubes 35 communicating with a receiving device 36 at the side of the container having transverse louvres 38 inclined as shown.  Solvent supplied to the latter from a nozzle 44 disposed in the wall 28 of the surrounding casing, discharges on to the top of the material in the next lower container.  The nozzles 27 discharge into collecting devices 30 secured to the inner side of the wall 28 which are individually or in groups connected to piping 91 . . . 96 aforesaid. Adjacent to the containers, the collecting devices 30 are provided with louvres 34 through which the miscellas are directed from the nozzles 27.  In the horizontal type of apparatus the series of injection nozzles 71 . . . 77, Fig. 5, discharge directly through the perforated-base containers 11 on to the collecting trays 51 . . . 57 for re-circulation by pumps 81 . . . 87 respectively. Overflow of miscella proceeds from tray to tray in the direction indicated by arrows A, opposite to the movement of the containers shown by arrows B, the full miscella being discharged from tray 57, below the feed end of the container path by an overflow weir 68 to storage.  Each container is inverted at the opposite end of the container-chain for discharging the extracted material into a trough 49 with discharge screws 50, the containers then being restored to the upright position before re-filling from a hopper 60.  In a modification the containers may move in the opposite direction, the other parts of the plant being re-arranged accordingly.  To enable the supply of miscella to selected sprays to be cut off in the horizontal type of apparatus, the sprays may be mounted on a common header longitudinal to the run of containers divided into main sections each partly over a collecting tray with an ancillary section therebetween over the junction between the trays, the sections being divided by valves and the ancillary section being the length of a container.  Means on the container closes the valve at the rearward end of the ancillary section as the trailing edge of the container passes below it and opens the valve at the other end of the section as the leading edge of the container passes below it.  The sprays in the ancillary section then receive miscella from the forward main section of the header.  After the container has passed the ancillary section the valves are interchanged and the sprays in this section receive miscella from the rearward main section of the header.  Specification 156,905, [Class 91] is referred to.