Plug seal for solvent extraction columns

Claim 1

EXTRACTION APPARATUS, COMPRISING IN COMBINATION A CHAMBERED, CYLINDRICAL, UPRIGHT EXTRACTING TOWER HAVING A BOTTOM FLOOR PROVIDED WITH A DISCHARGE OPENING, A CYLINDRICAL BARREL HORIZONTALLY DISPOSED BENEATH SAID FLOOR AND PROVIDED WITH AN IMPERFORATE FEEDING SECTION, MEANS PROVIDING A DISCHARGE PATH BETWEEN SAID DISCHARGE OPENING AND SAID FEEDING SECTION, A PORTION OF SAID BARREL ADJOINING SAID FEED SECTION CONSTITUTING AN EXPRESSING SECTION, THE CYLINDRICAL WALL OF SAID EXPRESSING SECTION BEING PROVIDED WITH PERFORATIONS TO PERMIT LIQUID ESCAPE THERETHROUGH, ANOTHER PORTION OF SAID BARREL CONSTITUTING A PLUG-FORMING SECTION AND BEING DISPOSED ADJACENT SAID EXPRESSING SECTION AND REMOTE FROM SAID FEEDING SECTION, THERE BEING MEANS FOR CONTINUOUSLY ADVANCING SOLID MATERIAL THROUGH SAID SECTIONS IN THE ORDER MENTIONED, CONSISTING OF A ROTATABLE SHAFT EXTENDING THROUGH SAID BARREL AND PROVIDED WITH A CONTINUOUS MULTIPLE-TURN FEEDING SCREW WITHIN SAID FEEDING SECTION AND AN EXPRESSING WORM HAVING A PLURALITY OF LONGITUDINALLY SPACED WORM FIGHTS WITHIN SAID EXPRESSING SECTION, THE CYLINDRICAL BARREL WALL SURROUNDING SAID PLUG-FORMING SECTION BEING IMPERFORATE, A YIELDING CHOKE BEING PROVIDED AT THE END OF SAID PLUG-FORMING SECTION REMOTE FROM SAID EXPRESSING SECTION, JACKET MEANS CONSTITUTING AN EXPRESSED LIQUID COLLECTING HOUSING SURROUNDING THE PERFORATE PORTION OF TH EXPRESSING SECTION OF SAID BARREL, AND LIQUID TRANSFER MEANS COMMUNICATING WITH SAID HOUSING AND WITH SAID TOWER FOR RETURNING EXPRESSED LIQUID TO SAID TOWER.