A homogenization silo is used to mix particles inside a silo using the circulation of particles. A pneumatic conveying system carries particles from the exit and re-enters them from the top. Here, we use a `periodic` boundary to simulate the action of the pneumatic conveyor system for circulating particles. Particles exiting from the bottom are re-entered from the top using this boundary (`periodic`).
The simulation case setup is essentially similar to the [`layeredSiloFilling`](https://github.com/PhasicFlow/phasicFlow/tree/main/tutorials/sphereGranFlow/layeredSiloFilling) tutorial. There is also another change with regard to `layeredSiloFilling`. The exit gate is opened after the filling phase of the silo (see `settings/geometryDict` for more details).
