Determination of Bulk Flow Property of tef Flour and Seed and Design of a Silo

The flowability of the bulk materials was determined after development of yield locus, wall yield locus, and effect of time consolidation was measured. Data from the obtained curves were read and important parameters such as unconfined stress, major consolidation stress, angle of internal friction, angle of wall friction, and effective angle of internal friction were for further design of silo calculation made ready. Diagrams and relationships developed by Jenike were used to find important silo discharge opening parameters such as the angle of the conical or wedge shaped opening and critical silo opening diameter and width. The relative difference between tef flour and tef seed was made in which the flour has a characteristics indicator of particle size distribution with lower dimension and the flour is cohesive and less flowable and accordingly needs more generous discharge parameters. The comparison between the flour and the seeds was shown in the measurement of flowability indexes and also reflected clearly on the designed silo discharge opening parameters.