Discharge Regimes of Polydisperse Powders through Conical Hoppers under Positive Flow Conditions

İngilizce (OpenAlex)

Discharge characteristics of polydisperse powders through a conical hopper were experimentally investigated by observing the solids discharge regimes under different positive pressure differences (i.e., ΔP > 0) and also measuring the corresponding solids discharge rates. The observations and measurements were systematically conducted at least four diameters of hopper orifice (2.5 mm ≤ Do ≤ 30.0 mm) under five positive ΔP values (0 Pa ≤ ΔP ≤ 1405 Pa) for the test powders: river sand, zeolite, fertilizer, and sawdust. Effects of positive ΔP on both discharge regime and solids discharge rate are first predicted for different orifice diameters and test powders in this study. One of the novel results on the discharge regime is that increase of positive ΔP value up to a critical value conserves or successively stabilizes the discharge regime observed when ΔP = 0 (i.e., for gravity flow condition) through the same hopper. However, the additional increase of positive ΔP over this critical value destabilizes the discharge regime, as in conformity with the effect of increase in negative ΔP cited in the literature.