What Is Ratholing in Silos?

Ratholing, also called channel flow, is a flow pattern where material only moves through a vertical channel above the outlet. Up to 80-90% of material can remain behind. It is the opposite of mass flow, where all material moves downward simultaneously.

Funnel flow design without sufficiently steep hopper forces material into a channel pattern. High wall friction prevents material along walls from moving. High cohesive strength keeps the channel stable. Consolidation over time makes wall material even stronger.

Sudden collapse of the channel wall can cause uncontrolled discharge. The FIFO principle is completely violated. Structural risk from asymmetric loading. Danger for personnel — the channel wall can collapse and bury anyone entering the silo.

Hopper redesign for mass flow — effective but expensive. Internal cones create new problem areas. Vibrators have limited effectiveness. None of these solve accumulated material along the walls.

Mechanical cleaning removes stationary material along the walls and restores full capacity. BinWhip technology reaches wall material that traditional methods cannot access. Regular maintenance prevents the problem from building up again.

Suspect ratholing in your silos? Blue Power can inspect and assess the situation without personnel needing to enter the silo.