DEM study of particle conveying in a feed screw section of vertical rice mill

Abstract

This paper presents a numerical study on the particle conveying in a feed screw section of vertical rice mill based on the discrete element method. The effects of key parameters, including rotational speed, height and type of feed inlet, are investigated by a series of controlled numerical experiments. The results showed that the better uniformity of flow pattern within the conical hopper is achieved when the drawdown index is less than 0.06; mean residence time and variance of residence time values gradually decrease when the cutting edge of feed inlet changes clockwise. The effects of rotational speed and height of feed inlet on quantitative variations of conveying performance are significant. In particular, the relationship between microscopic flow characteristics of the particles and macro performances of screw conveying can be described based on the method of polynomial fitting. The findings are useful to understand particle conveying of a vertical feed screw section that applies the lateral hopper-feeding form.