GB512660A - Improvements in continuous treatment of solid materials by means of solvents - Google Patents

Abstract

512,660. Making extracts. TORRILHON, H. M. LAMY-. Jan. 11, 1938, Nos. 844 and 845. Convention dates, Jan. 11, 1937, and March 26, 1937. [Classes 81 (i) and 127] [Also in Group III] In a countercurrent extraction process, the solid raw material moves solely under gravity without propelling members or conveyers, and the solvent is injected into the extraction chamber in measured amounts. Seeds, oil-cake, beetroots, plants, or bark are treated with solvents to extract oils, sugar, essences, or tannin respectively. Raw material is fed into a hopper 2 passes down the unobstructed extraction column 1 to a passage closed by a distributor consisting of a rotating disc 3 and adjustable scrapers 5. The amount of material passing through the extractor is thereby controlled. The extracted material then falls into a chamber 7 at the bottom of which is a gate 9 consisting of a rotating wheel of cells which are in turn brought into register with a discharge opening. The material then falls upon a draining rack 14, where it is sprayed with solvent from a jet 17. The washed material is then conveyed to a drier 16. The washing-solvent is forced at a constant rate by a pump 18 into the chamber 7 communicating with the extractor 1. The solvent then passes up through the extractor, and the resulting extract passes through filter tubes 19 to a still. In a modification, a screw or bucket conveyer is interposed between the bottom of the extractor 1 and the draining rack 14. In a further modification two superimposed extractor chambers, are used in which the solvent extract taken from the top of the lower extractor is injected into the top of the upper extractor, whereby in the lower extractor counter-current extraction is effected, and in the upper extractor, solvent and raw material both flow downwards together. The solventextract flows off from an intermediate chamber between the two extraction chambers. This form is preferred where the solvent-extract is more dense than the solvent. The drier 16 mav consist of a series of heated chambers having conveyers and if desired operating under reduced pressure. Inert, heated or cold, gas may be admitted. The evolved vapours pass through a filter fabric mounted on a foraminous tube submitted to jerks.