GB989778A - Improvements in or relating to the heat treatment of particulate solid materials - Google Patents

Abstract

<PICT:0989778/C4-C5/1> A method of subjecting particulate solid material to a heat treatment, e.g. for rendering small volatile coals smokeless or for the rapid heating of granular anthracites, comprises introducing the material (in a carrier gas) at 1 into a gaseous stream, e.g. produced by a burner 3 for heating a vessel 6, so that the material surrounds the stream, and introducing the stream and the material tangentially into the vessel 6 one or more inlets so that a swirling motion is then induced in the stream, subjecting the stream and solid to heat treatment and separating the treated solids and the gas in the vessel 6. The separation is carried out by centrifugal action in the vessel 6, solids leaving at 7 and gases at 8. The vessel 6 may be externally heated or, if air is used as the carrier stream at 1, the heat of reaction in the vessel 6 may be wholly or partly sufficient. Heated sand may be introduced into the vessel 6. The gases leaving at 8 may indirectly preheat the carrier gas/solid supply, see Fig. 3 (not shown), and the air and fuel (gas) supply to the burner 3. In a further embodiment, Fig. 4 (not shown), the carrier gas and entrained solids are delivered to a cyclone separator to which gases from the line 8 are also delivered, the solid material being heated in the separator. On leaving the separator, the solids are entrained in a second gas indirectly preheated by the gases leaving the separator, for delivery to the vessel 6. In both the embodiments of Figs. 3 and 4, a cyclone separator may be included in the gas line from the vessel 6 just prior to the indirect heater, and coal fines from this separator may be used as fuel in the burner 3.