Discharge characteristics of binary particles in a rectangular hopper with inclined bottom

The stable discharge of particles through the hopper plays a key role in many industrial applications. In order to investigate the discharge characteristics of binary particles in a rectangular hopper with an inclined bottom, the discrete element method (DEM) was used to simulate the discharge process. The accuracy of DEM was validated by comparing calculated and experimental values. The influences of geometric parameters (hopper width, orifice width, and hopper angle) and particle parameters (friction coefficient between particles, friction coefficient between particles and wall, fine particle mass fraction, and particle size ratio) on the discharge were studied. Some interesting results have been found that the effect of hopper width on discharge is minimal. The mass discharge rate is linearly related to the 3/2 power of orifice width, and it can be predicted by the modified Beverloo correlation which developed for a rectangular hopper with flat bottom. The mass discharge rate increases exponentially with the decrease in hopper angle, which is different from that of monosized particles. The mass discharge rate is more sensitive to low friction coefficient, and the friction coefficient between particles plays a leading role. Fine particles can promote the discharge process, and this effect is enhanced as particle size ratio increases.