Apparatus for drying a moist particulate material with superheated steam

An apparatus for drying a moist particulate material having a non-uniform particle size with superheated steam, said apparatus comprising a lower cylindrical part (2) having a number of parallel, substantial vertically elongated chambers (6, 7) located in ring form, one or more of the chambers (7) having a closed bottom and the remaining chambers (6) having a steam-permeable bottom (8), the adjacent chambers (6) being interconnected through openings (62) in the chamber walls (5) at the lower ends of the chambers (6), and an upper conical part (3) which is also divided into chambers (10), which at its lower end is connected to the chambers (6) of the cylindrical part (2) of the apparatus and which at the top is connected to a transfer zone (32), the chambers of the conical part (3) of the apparatus being divided into smaller chambers (10) by means of inclined guide plates (11), means (15) for supplying moist particulate material to a chamber (6) having a steam-permeable bottom, means (13) for discharging dried material from a chamber (7) having a closed bottom, means (51) for supplying superheated steam to the area below the steam-permeable chamber bottoms (8), means (51) for discharging steam from the transfer zone, and means (20) for reheating the discharged steam and recirculating it to the area below the steam-permeable chamber bottoms (8), characterized in that at least part of the inclined guide pates (11) in the conical part (3) of the apparatus is provided with means (70, 71) for heating the plates (11).