Abstract
The angles of repose and the discharge-behavior from small holes under a slow agitation were studied on powders with particles of comparatively wide size ranges. Moreover, the shear-tests were done on these powders and from these data the interparticle cohesion at point of contact under zero compacting pressure was determined. The relations between this interparticle cohesion and the angle of repose or the discharge-behavior were determined. These results are summarized as follows.
1. The relation between the discharge-rate Q (ml/min) and the relative dimension of the orifice-area to the particle-area is represented by the following equation.
Q=a((φ/dp)2-(φ0/dp)2)
2. The relation between a and the reciprocal of (φ0/dp) is roughly linear.
3. φ0/dp increases monotonically with kF0/ρp3 and the relation between them is independent of the particle-shape.
4. The angle of repose increases linearly with F0/ρpdp3 and the relation between them is dependent on the particle-shape and in the range of small F0/ρpdp3 the angle of repose of the spherical particle is smaller than that of the irregular one.
5. The relation between the discharge-behavior and the angle of repose could be represented by the following equation.
φ0/dp=f(k(θ-θ0)/α)
