LAUSR

Abstract A screw feeder is mainly used in industries for conveying and elevating granular materials. Despite having a simplistic design, the mechanics of conveying the material is quite complex. The flow behavior of particles in a screw feeder is influenced by its geometric and operating parameters. In this study, the authors focus on the change in flow behavior by changing these parameters, using the discrete element method (DEM) simulations software LIGGGHTS. The mass flow rate measurement and visual examination of the particle fill level in our experimental studies served as model validation. The simulations were conducted with monosized spherical particles, and a mass-based uniform distribution of particles, with diameters between 2 and 5 mm. A mass based uniform size distribution was considered to represent multisized biomass particles, with particle properties of a representative biomass being used. The simulations quantify the screw feeder performance in terms of mass flow rate, average particle speeds (axial, radial, and swirl), and average contact forces (normal and tangential). The average particle axial and radial speed increased and swirl speed decreased with increasing rotational speed. The increase in feed rate and flight pitch ratio enhances the average radial and swirl speed of particles. The swirl and radial speeds are highest for smallest particle diameter for all three varying parameters. The average normal and tangential contact forces increased with increasing rotational speed, particle feed rate and pitch flight ratio and was found highest for biggest particle diameter.