GB649010A - Improved method and apparatus for leaching a soluble portion from an insoluble portion of a material - Google Patents

Abstract

<PICT:0649010/III/1> In the extraction of oil from seeds a soluble portion is leached from an insoluble portion of the material by dividing the material to be extracted into a plurality of separate and preferably equal quantities, passing each quantity in countercurrent to a leaching solvent, treating each quantity with a body of the solvent and maintaining each quantity in an intimate and static contact with the solvent for a predetermined <PICT:0649010/III/2> <PICT:0649010/III/3> <PICT:0649010/III/4> <PICT:0649010/III/5> period of time before draining the solvent and solubles dissolved therein from the charge, and repeating the steps of alternately flooding and draining each separate quantity of material throughout the cycle, both the countercurrent movement of the material and solvent and the washing and draining of the separate quantities of the material being automatically co-ordinated by a cyclic sequence control. According to one embodiment, Figs. 1 and 2 (11728/48), raw extraction material is fed through a slide valve 10 in succession into each of six sectors of a clock-wise-rotating drum 13. Fresh extracting solvent is delivered through an inlet valve assembly 29 into the sector in position 19 containing nearly spent material. After an intimate and quiescent contact of predetermined duration, an outlet valve 18 situated between a radial dividing wall 16 of the sector and a screen 17 is automatically opened by a valve mechanism 28, and the partially enriched solvent drains through the screen 17 into the compartment in the base of the casing registering therewith and thence through an outlet 5 to a storage tank from which it is delivered to a sector 20 through the assembly 29 when the latter is automatically opened in response to a sequence cycle controller. The progressively enriched solvent proceeds similarly in sequence through the sectors in positions 21, 22 and is then led away for solvent recovery. The raw extraction material after delivery through a slide valve 10 into the sector in position 23 is subjected to successive extractions in positions 22 to 19. Finally in position 24, a cam 39 controlling a swing plate valve 36 in the bottom of the sector engages a stop 40 causing orifices 35 and 37 to register whereby the contents of the sector fall into a discharge hopper 6. According to another embodiment, Figs. 1, 3 and 4 (28257/48), raw extraction material is delivered into a compartment 2 in position 2f by means of a feed screw 3 and an open slide valve 13. The slide valve is closed and by means of hydraulic rams 5 acting on a rack wheel 7 the compartment 2 moves into a position 2a. There the appropriate valve-controlled inlet pipe automatically delivers into the compartment miscella obtained from the adjacent compartment in position 2b. The solvent/miscella rests in contact with the material for a time determined by a sequence cycle controller, whereupon a valve 24 is automatically opened by the action of a hydraulic ram allowing the solvent to filter through a screen 22 into a receiving well 27. After a determined period of drainage the valve 24 is closed and the compartment 2 is automatically moved to the positions 2b and 2c where similar washings and drainings are effected. In position 2d the nearly spent material is extracted with fresh leaching solvent. In position 2e, a toothed stay plate 14 meshes with a segmental gear wheel 15 and the action of a hydraulic ram 17 determined by the sequence controller rotates the compartment through 180 degrees and ejects its contents. Fresh leaching solvent is introduced above position 2d and effects an extraction in this position and then in positions 2c, 2b and 2a. Solvent from position 2a may be used to spray the entering material through sprayer 21. The process may be modified to include the recirculation of leaching solvent at any one or more particular points in the cycle whilst maintaining an overall countercurrent flow.