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

An investigation into the impact of particle properties on flow behaviors

“…where 𝑑 50 is the median mass-based diameter, (𝑑𝑃 𝑑𝑧 ⁄ ) 0 = ( 𝜇 g is the dynamic gas viscosity. He also [83] measured the discharge rate under different positive pressure differences and observed the corresponding solids discharge regimes and by the experiment in a conical hopper and revealed the relationship between the positive pressure ∆P and the discharge regime.…”

“…Despite the seeming simplicity of function, flow problems including erratic or stunted flow, dead zones, segregation, and dust explosions are prevalent [1,133,134]. To resolve such issues, an in-depth understanding of the mechanisms underlying the different discharge behaviors [9,83], for example, due to different hopper configurations [17,34,135] and different particle properties [10,12,14,27,136],…”

“…The dependence of discharge rate and wall stress on particle interactions have been investigated using the discrete element model (DEM), and it was found that the proper accounting of inter-particle interactions is critical for more accurate predictions of discharge rates [135]. The effect of differential pressure ( ∆ P) on discharge rate in a conical hopper was experimentally studied, which indicated that increases in ∆P increased discharge rate up to a critical ∆P after which the discharge regime destabilized, and that the critical ∆P depended on hopper orifice diameter and physical properties of the particles like size distribution and particle density [83]. Recently, the discharge rate in conical hoppers was assessed using an elastoplastic model implemented with the Eulerian finite element method (FEM) approach, which demonstrated that material dilation and internal frictional angle markedly affect the discharge rate particularly for steep cones (cone angle < 45°) [144].…”

“…Correspondingly, the understanding of the principles underlying particle packing and flow in the hopper has been the focus of many studies, due to the importance of the flow characteristics for the design and operation of the hopper [14,157]. Many factors (e.g., hopper geometry [9,75,80,[158][159][160], particle properties [10,57,101,[161][162][163][164], and flow conditions [74,83,165]) may affect the flow dynamics. The focus of this study is on particle shape, which has been shown to have a significant influence on the particle flow behaviors [56,[166][167][168].…”