Material dryer with air and screw agitator

Apparatus adapted for drying products generally moistened throughout, as by organic solvents;

• and comprising a generally cylindrical vertically oriented vessel with a downwardly conically tapered lower end portion terminating in a product discharge opening, and a closed top end portion with means for admitting products to the vessel;
• agitating means centrally mounted for rotation within the vessel for distributing products therein and including a rotating shaft centrally and vertically disposed in fixed position within the vessel and carrying a skeletal helical screw of a radial extent at least approximating surface contact with the interior surface of the vessel and extending substantially throughout the vertical extent thereof including the tapered lower end portion to the product discharge opening;
• and conduit means including a feed conduit for directing drying gas to the tapered lower end portion of the vessel above and transversely across the discharge opening and the path of the helical screw in the tapered lower end portion of the vessel for movement through the agitated products and in countercurrent to movement of the products toward the discharge opening within the outer radial extent of the skeletal helical screw.