Silos flow limits

The mass-flow and funnel-flow limits in silos are well known and have been used extensively in proper design. The limits for conical hoppers and plane hoppers depend on the hopper half-angle 9, the effective angle of internal friction 5 and the wall friction angle ( ). Once the wall friction angle and effective angle of internal friction have been determined by experimental means, the hopper half angle 0 may be determined. In function form it can be expressed as... 

If your design is close to the mass flow/fliimel flow limit, consider the possible effects of slight changes in material properties or the interior surface of the silo (particularly its hopper section). The latter is particularly important if the hopper walls are likely to be polished with use. 

While the benefits of a properly designed system are many, so are the pitfalls that must be avoided by the system designer. An ill-conceived material flow pattern or poor choice of system elements can result in operational limitations or maintenance headaches which reduce the expected benefits. In this section, we will examine each element going into a system, such as silos, conveying systems, dryers, blenders, and then take an overview of how they fit together. 

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