DEM study on the discharge characteristics of lognormal particle size distributions from a conical hopper

摘要

This study employs the discrete element method (DEM) to investigate the impact of the widths of lognormal particle size distributions (PSDs) with the same mean particle diameter on hopper discharge behaviors, namely, discharge rate, particle velocities, and size-segregation. Results reveal that (i) the hopper discharge rate decreases as PSD width increases; (ii) the mean discharge rates are constant with time, but the fluctuations increase as the PSD width increases; (iii) the overall size-segregation increases with PSD width; (iv) the overall mean particle diameters of the narrower PSDs do not exceed the initial mean of 5 mm, whereas that of wider ones do; (v) the relationship between PSD width and particle velocities is non-monotonic with no consistent trends; and (vi) no direct correlation exists between particle velocity and size-segregation. The results here provide valuable insights on the behavior of the prevalent polydisperse mixtures in hoppers. (c) 2017 American Institute of Chemical Engineers AIChE J, 64: 1174-1190, 2018