Funnel flow silos are used for more granular types of materials where material degradation is not a worry. Funnel flow silos are generally 20-30% less expensive than mass flow silos.
With this type of silo, the first materials in are the first materials out. Upon emptying there is a flow channel in the middle allowing the material to drain first and the side material to flow into the channel as the silo empties. This can create flow channels in some materials and can potentially make the product susceptible to segregation issues. The cone angles for the funnel flow silos are 45-60 degrees.