Chapter 9 - Flow of solids and slurries in rotary drums

Abstract

Rotary drums are widely used in the chemical and metallurgical industries for processing large volumes of granular solids. This chapter describes the flow of solids and slurries in rotary drums. In the chemical process industries, drying of solids can be achieved easily in rotary kilns, where hot gases flowing axially along the kiln are contacted with the cascading solids. In the environmental areas, rotary drums can be used to treat contaminated soil. In such a process, a microbial culture together with nutrients is added to the soil. A low rotational drum speed can provide excellent mixing action for oxygen transfer to allow the microorganisms to decontaminate the soil. Rotary drums also are employed for bitumen extraction in the hot-water process and in simultaneous extraction and upgrading of bitumen in direct thermal processes. Optimizing the operating conditions for these drums as feed flow rate, drum speed, and inclination is critical. Parameters such as feed flow rate, feed solids concentration, drum internal, and endplate design can be adjusted to obtain the desired effects.