DEM study of white rice separation in an indented cylinder separator.

The precise separation of whole and broken rice is an issue of great significance in rice processing industry. This paper presents a numerical study on the rice separation in an indented cylinder separator based on the discrete element method. The probability density function of escape angle of whole and broken rice was investigated at 10% filling level for various rotational speeds and indent numbers. Hellinger distance, a statistical estimate used to quantify the difference between two probability distributions, was adopted to measure the separation ability. It was found that the Hellinger distance appears to initially increase to a maximum and then decrease with the increase in rotational speed. While the Hellinger distance increases to a maximum value then keeps stable with the increase in indent number. After obtaining the optimal operating condition for the best separation, the position of trough was decided based on the boundary of parabolic trajectories of whole rice after leaving indents. The aim of this work is to determine the best parameters for the indented cylinder separator based on the understanding of separation progress at a particle scale, providing a foundation for the numerical investigation of indented cylinder separator. Unlabelled Image • Separation of rice by indented cylinder was simulated using discrete element method. • Effect of rotation speed and indent number on escape angle distribution was analyzed. • Hellinger distance was used to quantify the difference of escape angles. • The position of trough was decided based on the boundary of whole rice trajectory. • Rotation speed ratio of 55%, indent number of 72, trough angle of 60 is the optimum. [ABSTRACT FROM AUTHOR]