Lime Silo Retrofit
This is an example of a solution to fix a lime bin that is suffering from chronic bridging.
Why the Existing Silo is Suffering From Chronic Plugging and Inconsistent Discharge
The existing bin is a silo with a steep cone that converges to a vibratory feeder. The vibratory feeder employs a shallow cone and a small outlet.
In summary, the silo is suffering from chronic plugging because the shallow cone of the vibratory feeder is inducing a funnel flow discharge pattern, while constricting the material discharge to too small an opening. Funnel flow (which is a first-in, last-out discharge pattern) can be made to work with a large discharge outlet. However, when the discharge outlet is small, gravity is insufficient to overcome the strength of the bulk solid at the discharge outlet, and hence chronic bridging and rat-holing is expected.
The solution to fixing this problem bin has two parts. The first half of the solution is to rip out the funnel flow cones, and replace them with a steeper mass flow cone and mass flow chisel hopper. Doing so fixes the geometry of the silo such that if the Feeder were removed, the entire bin would self-empty with gravity in a mass flow or first-in, first-out discharge pattern. The second half of the solution is to pair the new cone and hopper with a Kamengo Feeder. The reason for doing so is that the Kamengo Feeder withdraws material evenly from its entire opening, which by definition is necessary to actually achieve a mass flow discharge pattern in the silo. If the Feeder instead withdrew material unevenly, a funnel flow discharge pattern would ensue (regardless of the bin geometry), and rat-holing would occur.
To learn more about the physics of storage bin and feeder design as well as the root causes of bin plugging, please visit KamengoU.