Columnist Jack D. Hilbert answers a reader’s question about how material characteristics affect flow and provides troubleshooting advice for closed-loop pneumatic conveying.
There are many examples of this flow problem and several possible causes. For example: 1. When discharging by gravity from a silo, pellets exhibit an hourglass flow -- predictable and steady throughout the entire discharge. But if the material has nonuniform or unusually shaped particles, the particles can interlock, forming agglomerates or nests. These may be too large to discharge from the silo outlet.