Common Bulk Material Discharge Problems and Their Solutions

Locate the actual restriction

Observe where flow stops: within the FIBC, at its spout, in a chute, above a hopper outlet or at a feeder. Record whether flow is intermittent, completely stopped or concentrated in a narrow channel. The visible symptom at the production line can originate further upstream. A sketch of the entire material route is often more useful than an isolated equipment photograph.

Check packaging and interfaces

A closed or poorly arranged liner, an obstructed outlet and a consolidated powder mass require different remedies. Examine the bag support and unloading arrangement using a safe method. Identify any interface that reduces the effective outlet or allows material to accumulate between operations.

Investigate hopper flow separately

Arching is a stable obstruction above an outlet, while ratholing leaves material outside a central flow channel. Hopper geometry and the material’s measured flow behaviour inform the remedy. Do not assume a bulk bag conditioner can fix a downstream hopper or that adding vibration is always appropriate.

Choose a measured intervention

Test a suspected cause before purchasing an unrelated machine. A sound FIBC with consolidated contents may justify conditioning trials. Exposed lumps may justify a breaker trial. A hopper problem may require specialist flow testing and vessel changes. Define discharge rate, consistency and residual contents as acceptance criteria appropriate to your plant.

Bulk Bag Conditioner

Hydraulic Bulk Bag Conditioner

Technical references

Flexicon: bulk bag conditioning terminology

National Bulk Equipment: application-specific conditioning

GIMAT: lump breakers and pre-breakers

Jenike & Johanson: arching and ratholing

HSE: Safe handling of combustible dusts