The influence of feeder structures on discontinuous precision dosing of powders by a screw feeder

Abstract

Abstract. In order to improve the accuracy and the stability of screw discontinuous dosing, the study on the discontinuous dosing performance of screw feeder with different feeding structures was carried out. Firstly, the concept of screw discontinuous dosing was put forward, and the primary influencing factors of discontinuous dosing accuracy and stability was analyzed theoretically. Considering the existing powder particles gravity flow and instable motion at the screw feeder opening, the Sub-feeding device constituted by six baffles was designed and fixed before the opening of the screw trough. Mechanical analysis about effect of feeding structure on the particles and the estimation formula of feeding quantity were presented. Secondly, the screw feeder with a blade diameter of 38mm, and an axis diameter of 13mm was studied in this paper, the impact of the different discharging structure on the discontinuous feeding performance was analyzed by using the discrete element method, and appropriate structure parameters of feeding device structure was designed. Finally, a prototype was made, and a series of experiments of screw discontinuous feeding were conducted. From the study on the screw feeder, it was found that adding thin baffle within the screw feeder was effective in improving the stability and the accuracy of feeding.