FR2289218A1 - Sol. matl. extn. from solids, e.g. for sugar beet - by countercurrent contact with liq. in compartmented rotating drum - Google Patents

Abstract

A plant for extracting solid materials by countercurrent contact with a liq. incorporates a horizontal rotatable drum with an outer shell in which are an axial central cylindrical duct and two internal shells, one near the outer shell and one near the duct. Between the two internal shells are radial partitions extending the length of the drum and forming compartments, each in section a segment of a circle, the apex of which is at the axis. the internal shells and the partitions are permeable to liq. In the central duct a fixed support carries pipes which feed liq. to the compartments and carriers arms terminating in rollers which rotate against the inner surface of the duct. The drum has a cover at one end, in the form of a truncated cone, with a hole in the small apex through which liq. leaves and which determines the level of liq. in the drum, below the axis. At the large base of the cover is a screen with an opening in its lower part. Solids are charged to this opening by a pipe leading from a screw conveyor in a feed hopper, pass along the compartments, where sol. material is extracted, and are discharged by a screw conveyor at the outlet end. Method is esp. useful for extracting sugar from sugar beet or cane. The appts. is simpler in construction than existing plants and allows treatment of solid materials in relatively thin layers in compartments of which all the walls are filter surfaces and in which there is good contact between solid and liq. It allows of filling practically all the available vol. in the compartments, without risk of blockage during the flow.