Design and Operation of Continuous Rotary Calciners

In catalyst manufacturing, continuous rotary calcination is a thermal treatment process in which particles flow through a rotating drum with heated walls.  Although this process is widely used, there is a lack of predictive models for material flow and heat transfer, particularly upon scale-up.  This work aims at a fundamental understanding of the effects of operation, design, and material properties on residence time and temperature distributions in rotary calcination processes to provide a methodology for scale-up.

For successful calciner performance, the residence time of the particles in the calciner must be longer than the time required for heating and calcination of the particles.  This problem can be separated into axial and radial processes.  In the axial direction, residence time and dispersion will be important, requiring experiments in full calciners.  In the radial direction, heat transfer and dispersion will be important, requiring experiments and discrete element method (DEM) simulations in cross-sections of the calciner.  This presentation will discuss results of studies on the competing axial and radial processes and their implications for scale-up of continuous rotary calciners.