Patent ID: 6811765
Filing Date: 2004-11-02
Classification: B01J,C22B,F27B,Y10S

Abstract:
Process for the thermal treatment in a reactor of a fine-grain material with an average grain size under 1000 &mgr;m comprising the steps of:(a) establishing and maintaining, in a walled reactor space, a fluidized bed of suspended coarse grain material of 1 to 10 mm grain size and imparting a high temperature to the atmosphere of such space and the coarse grain material; (b) inserting the fine grain material to be treated immediately above the bottom of the fluidized bed and imparting a circulating motion to the fine grain material in the reactor space; (c) subjecting the fine grain material to thermal treatment for a chemical or physical reaction; and (d) transporting the fine grain material pneumatically through a diffuser neck having an opening ratio of fluidized-bed area to diffuser neck area within a range of 6 to 9 and a linear ratio of diffuser neck length to diffuser neck diameter within an 0.5 to 1 range from the fluidized bed into an upper oven segment above the reactor where the fine grain material is cooled to below its softening or agglomeration temperature.