Numerical Validation of a Screw Conveyor Design Method

Abstract

Screw conveyors and feeders are a common way to transport a variety of granular bulk material. There is also the possibility of using them as reactors themselves, where they represent an interesting alternative to other common reactor types, for example, the pyrolysis of biomass or plastics. However, the scale-up and design of screw conveyors remains a challenging topic. Even though the fundamental design has been applied for several decades, things like granular mixing and transport are still not fully understood. A lot of the research on the transport of screw conveyors is focused on single-screw setups. This leads to the reliance on empirical data or in-house experience for conveyor design. For that reason, it is important to develop reasonable guidelines and design tools that are based on scientific principles, which can be further validated by experiments and simulations. In this work, findings from a dimensional analysis are combined with auger reactor design criteria that were developed in the 1960s based on extensive experimental work and that were only available in the German literature up until now, and the resulting assumptions are then tested with the help of discrete element method simulations.