Process and device for the thermal treatment of a mixture of finely

Abstract

Mixtures of finely divided solids and gases are subjected to a thermal treatment by feeding the optionally heated gas tangentially into the lower section of an axially symmetrical vessel, adding the solid to the gas at the latest in the vessel, heating or cooling the mixture of solid and gas in the vessel through the wall thereof and discharging the mixture in the upper section of the vessel. The gas/solid mixture is conducted in the vessel in upward direction in at least two annular flows substantially closed in themselves and in horizontal position one above the other, the transport of the solid from one annular flow to the adjacent overlaying annular flow taking place in a concentric inner zone of the annular flows. The device used is provided with a jacket with heating or cooling means over at least part thereof, at least one tangential inlet and outlet in the lower and upper part of the vessel and in the interior between the inlet and outlet at least one annular baffle plate is closely fitted on the wall of the vessel.