Numerical simulation approach for predicting rice milling performance under different convex rib helix angle based on discrete element method

Rice milling, as a critical process in rice processing, determines the subsequent storage, nutritional quality and economic value of rice. Unfortunately, due to the complex milling mechanism and few quantitative methods to predict the milling effect of rice, the improvement of the key components of rice mill has become one of the issues restricting the development of rice milling industry. In this work, rice milling performance in rice mill with different convex rib helix angle alpha was studied through the combination of simulation and experiment. Modified actual milling time distribution can accurately quantify the uniformity of rice milling. Milling uniformity of rice gradually deteriorated with alpha. Compared with traditional evaluation methods, the regional energy algorithm can reflect the rice milling degree more accurately. Besides, the friction effect between rice become more intense with increased alpha. These results can provide theoretical guidance for the parameter optimization of rice mill.