Influence of technical and technological parameters on the barley dehulling process

Abstract

Introduction. The research aim is to determine effect of duration of dehulling, the barley size and moisture, the rotation speed of abrasive discs, the abrasive grit and the load factor of the dehuller on the dehulling index. Materials and methods. The dehulling was carried out in laboratory dehuller (model ULZ-1) at the rotation speed of abrasive discs of 29.6±0.015 s-1 (1775±0.9 rpm) and 42.3±0.013 s-1 (2540±0.8 rpm) and removing of barley husks and meal was conducted in the laboratory aspiration duct of 60 mm width. Results and discussion. The research has shown that the increase in the dehulling duration the weight of the barley loaded to the dehuller, the rotating rate of abrasive discs and the load coefficient of the dehuller working chamber leads to the dehulling index rise. There exists the non-linear dependence between the load coefficient of the dehuller working chamber with the minimum point of the dehulling index for the large fraction of barley 0.27–0.28 and for the small fraction of barley 0.24–0.25. The influence of the barley weight and the load coefficient of the working chamber of the dehuller on the dehulling index occurs according to the curvilinear dependence with the minimum point of the dehulling index for the large barley fraction of 0.27–0.28 and for the small barley fraction of 0.24–0.25. The increase in the processing duration and the load coefficient of the working chamber of the dehuller leads to the increase of the dehulling index, but at the same time the minimum point of the dehulling index decreases from 0.29 to 0.25. As the size of the barley grows, the dehulling index decreases. The gain in moisture of the barley leads to the decrease of the dehulling index according to the linear dependence for both large and small barley fractions. Moreover, the small fraction has the bigger values of the dehulling index than the large one. The moisture influence on the dehulling index has linear dependence for both large and small barley fractions. As moisture increases the dehulling index decreases linearly, but at the same time the large barley fraction had lower values of the dehulling index than the small one. The increase in abrasive discs grit leads to the dehulling index decrease according to the curvilinear dependence. At the grit of 80 the dehulling index gets the constant value and its change depends on the duration of processing. Conclusion. The influence of technological parameters of barley grain on the dehulling index has linear dependence, and machine parameters affect the dehulling index according to curvilinear dependency. These results must be considered when evaluating the effectiveness of dehulling and the development of the process model.