GB504956A - Improvements in or relating to apparatus for drying and heating ores, stone, slag, and other materials - Google Patents

Abstract

504,956. Rotary - scraper drying apparatus for stone, ores, or slag PRIEST, C. F. Dec. 23, 1937, No. 35638 [Class 34 (ii)] Stone, slag, ores, e.g. small iron ore and other materials, are dried in a fixed vertical casing 10 having on its inner side a series of ring trays 12 with central orifices 13 coaxial with the casing, in which is placed a rotary central shaft 14 carrying disc trays 29 alternating with the ring trays, so forming annular spaces alternately at the shaft and casing; scrapers 34 on arms 33 on the shaft 14 engage the upper surface of the disc trays 29 and scrapers 32 on arms 31 on the casing engage the ring trays 14 so that material fed in at a top hopper 35 is passed down the casing, to which hot air is supplied at the top and other levels and is withdrawn at the bottom. The inclination and spacing of the frusto-conical trays decrease progressively downwards. The scrapers 34 may be tangential to the orifices 13 and are twisted at the ends. Material passes from the hopper 35 to a table 37 with supports 39 and a fixed cone 48, from which material is discharged through an annular space 38 to the trays by scrapers 43 rotating on arms 42. A vertically adjustable ring 51 regulates the feed to the table. Burnt gas from furnaces 60 passes up through pipes 61 with ducts 62, 66 having dampers 63, 67 into the casing ; some gas passes into a space 50 round the hopper 35 through holes 64 into the casing, whence all the gas is withdrawn at the bottom through an exhaust flue 65 in a discharge hopper 59. Cool air may be added to the hot gas through inlets 68 with dampers 69. The material falls at the bottom into a conical vessel 56 and hence through apertures 53 in the lower end of the hollow shaft 14 into a discharge hopper 59 and shoot 72 with a rotary sealing valve 73 to an elevator 74. The shaft 14 is rotated by a motor 24 and carries on radial arms 15 horizontal and vertical wheels 16, 19 running on tracks 17, 20.