Frictionless conveying of frictional materials
Following a brief review of the technology and previous analyses of vibratory conveying of granular materials, a general solution is derived for a well-known rigid-slab model of slide-conveying in open and closed conduits, with Coulomb friction at the walls. The solution is applied to periodic rectangular-wave and sinusoidal forcing, and it is shown that the rectangular-wave forcing admits ideal cycles in which the kinematically optimal transport is also thermodynamically optimal, in the sense that no energy is dissipated by sliding friction.
Transport of granular matter on an inclined vibratory conveyor with circular driving
I present a theoretical model to investigate the transport properties of granular materials on an inclined vibratory conveyor driven by circular oscillations. My model treats the granular dynamics on a vibratory conveyor as a combination of sliding and oblique hopping of a granular block with specific inelastic and frictional properties. The calculations show optimal transport conditions for the transport velocity efficiency, with an extra transport velocity efficiency minimum when the inclination of the vibratory conveyor is non zero. The investigations also show a current reversal under a certain inclination angle which does depend on the friction force. Keywords— Granular matter, vibratory conveyors, transport velocity efficiency, current reversal, optimal transport conditions.
Factors Affecting Material Movement on a Corrugated Vibrating Conveyor (Grainpan)
A corrugated vibrating conveyor (grainpan) was tested for the effects of various design variables on layer thickness and layer velocity of straw-chaff material and particles. Experimental design variables included conveyor feed rate, oscillation frequency, oscillation angle, tilt angle, and stroke length. Observed material layer and particle motions on such a conveyor were compared to predictions based on a theoretical analysis. Observations of optimum conditions for grain separation within the layer were made, as well as of particle behavior.