Review of the Principles of Flow of Bulk Solids

CIM Bulletin, 1970

A. W. JENIKE and J. R. JOHANSON, Jenike & Johanson, Inc., Consulting Engineers, Winchester, Massachusetts

A solid flows out of a bin provided that the outlet is sufficiently large so that stable obstructions to flow do not develop. The geometry and surface finish of a bin and the construction of the feeder determine the type of flow pattern which t hen develops within the bin. The pattern, in turn, affects the uniformity and consistency of the stream, segregation, caking, degradation, live capacity and the action of level measuring devices. In most bins now in operation, material flows toward the feeder through a channel which forms within the stationary solid. This is referred to as funnel f low. If the hopper of the bin is sufficiently steep and smooth and t he feeder capable of drawing material across t he whole area of the outlet, all the solid flows whenever t he feeder is in operation; this is referred to as mass f low. Mass-flow bins are usually far superior to funnel-flow bins; t heir initial cost is also usually higher. The paper describes the design criteria used in determining the minimum bin outlet needed for f low and t he bin geom.e. try needed for mass flow.
Keywords: Conical Hoppers, feeder, Gravity Flow, University of Utah, Winchester, Massachusetts, Design, Feeders, flow, Materials, Moisture content, Pressure, Storage, Strength, Temperature