The length of axially segmented lifters in flighted rotary drums: influence on solid transport

The impact of the length of axially segmented lifters, as used in industrial rotary drums, on their process behavior and in particular the axial solids transport is analyzed in this study. Experimental measurements of residence time distributions are carried out with a bare drum, with continuous rectangular lifters and with associated short rectangular lifters. Data analysis is performed with respect to mean residence times, drum capacity or drum load limit (back spillage) and axial dispersion. A significant impact of the axial lifter length was found and a different flow pattern with short lifters including a proposed pseudo back flow was observed. In addition to the experimental part, a first calculation approach to estimate the impact of the axial lifter lengths with a proposed efficiency factor is presented as a link to cross sectional considerations from the literature. Finally, first and novel design recommendations regarding the axial lifter length and the installation of front side walls at the lifter blades are derived from these findings.

Automated summary

This study analyzed the impact of the length of axially segmented lifters on the process behavior of industrial rotary drums, particularly on axial solid transport. Experimental measurements showed a significant influence of lifter length on mean residence times, drum capacity, and axial dispersion, with different flow patterns observed. Novel design recommendations for lifter length and the installation of front side walls at the lifter blades were derived from the findings.