Temperature analysis in flighted rotary drums and the influence of operating parameters

Abstract

Flights in rotary drums are used to improve the mixing and the heat transfer. They lift particles out of the solid bed to shower them as curtains through the gas phase of the drum. The number of particles and their distribution are influenced by several operational parameters. An indirectly heated flighted rotary drum was designed and constructed to conduct experiments relating transverse particle motion to heat transfer. Batch experiments divided into heating and cooling periods were performed with glass beads as reference material. The axial, circumferential and radial temperature distributions were measured. It was found that increasing the rotational speed as well as the volumetric airflow rate leads to quick temperature changes, while an increase in the filling degree results in a gradual decrease of the temperature drop during cooling.