PROCESS AND DEVICE FOR THE CALCINATION OF POWDEROUS MINERAL MATTER, ESPECIALLY IN THE CEMENT INDUSTRY

摘要

A process for the calcination of a solid pulverulent material comprises the steps of gasifying a solid fuel in a fluidized bed to produce an ascending current of gaseous fuel, and injecting the material in an oxidizing carrier gas into the ascending gaseous fuel current above the fluidized bed of solid fuel to disperse the pulverulent material in the gaseous fuel current, the flow velocity of the gases in the zone of injection of the material into the current being sufficient to entrain the material in the gases and to prevent them from falling into the fluidized bed. An apparatus for the calcination comprises a calcination chamber whose bottom is a grid carrying a bed of solid fuel through which air is blown to produce the ascending current of gaseous fuel in the chamber. An array of nozzles in an upper portion of the chamber is used to inject the pulverulent material suspended in the carrier gas into the chamber above the fluidized bed.