Denting of Circular Bins with Eccentric Drawpoints

Circular bins are structurally efficient in containing bulk solids provided the load on the bin is axially symmetrical. This requires the axis of symmetry of the bin to be vertical, and both charge into the bin and draw from the bin to be symmetrical with respect to the axis. With these conditions satisfied, the pressure from the stored solid on the bin is uniform, the resultant circumferential stresses in the bin are tensile, and the bin can be constructed as a light shell. Disturbance of the symmetry introduces bending moments in the shell and may cause denting of the walls. In steel construction, these dents are usually more unsightly than dangerous, because the plastic denting causes a redistribution of stresses which tends to relieve the bending moments. A light steel shell which dented under eccentric draw is analyzed. A formula which determines the maximum permissible radius of bin with eccentric outlets is proposed. The formula applies only to free-flowing bulk solids.