Abstract
A critical slope of hopper walls for mass-flow of bulk solids was calculated from both the angle of internal friction and the angle of wall friction by Jenike's method and others. Jenike's method was based on the criteria of existing solutions for the equations of the radial stress field. The angle of internal friction of various bulk solids was in the range of 26 to 35 degrees while the angle of wall friction on various materials ranged from 11 to 29 degrees.
Calculated results of the critical slope compared favorably with the results of the flow pattern of bulk solids which were observed in conical and pyramidal hoppers with wall slope of 48 to 84 degrees. Consequently Jenike's method was useful for the hopper design.
