Design, construction and evaluation of shear vane device for biomass yield stress determination

Abstract

Abstarct

Agglomerate followed by pelleting is one of the efficient methods to decrease transport costs and increase economic efficiency of biomass material. Understanding the rheological properties of biomass is necessary for pelleting process optimization as well as the design of devices with enough energy and pressure to determine the effect of different variables on the density and durability of pellets. The rheological properties of extruded material is depended to properties and moisture content of the raw material, used for extrusion. Therefore, in this study a shear vane was developed to determine the rheological properties of biomass materials. The output rotation of the electromotor was measured by a rotary encoder and the forces to the vane blades, inserted by the material, were measured by a bending loadcell. The experiments were done at moisture content levels of 35, 40 and 45%, and rotational speed of the shear vane container at three levels of 0.1, 0.2 and 0.3 rpm. The results showed that the higher maximum torque was achieved at 35% moisture content and rotational speed of 0.1 rpm. The lowest maximum torque was found at 35% moisture content and rotational speed of 0.2 rpm. The maximum shear stress and yield stress were obtained at 35% moisture content and rotational speed of 0.1 rpm while the minimum shear stress and yield stress were found at 35% moisture content and rotational speed of 0.2 rpm.