SIZE SEGREGATION DURING MASS FLOW—EFFECT OF DEPOSITION METHOD AND BIN SIZE

Abstract

Size-Segregation of granulated sugar during discharge from hopper bins was studied, with respect to the effect of bin size and bin fill method. Particle size distributions (PSDs) were analyzed from large and small mass flow hopper bins, using three different fill methods. Spoon-by-spoon deposition was used as a control, whereas funnel fill and inverted cone deflector fill were used to model industrial fill methods. Samples were taken during the discharge of the bins and PSDs were analyzed. For all three bin fill methods and both bin sizes, the PSDs were within the 95% confidence interval of the original, in bag, sugar PSD. The worst case scenario occurred at the 250 μm sieve size, where the greatest percent difference from original PSD value was observed. At 50% discharge for the 250 μm sieve the small (large) bin showed a maximum percent difference for spoon-by-spoon, funnel and inverted cone deflector fill of 21(4), 10 (9) and 6 (28), respectively. For the small and large bins, the largest percent differences of 49 and 37, respectively, occurred at 40% and 20% material discharged, respectively. The bin fill method did not affect the PSD significantly based on 95% confidence interval.