Powder Arching and Ratholing: Identify the Supporting Geometry

Identify the Material Response

Jenike distinguishes a stable arch spanning an outlet from a rathole in which material around a flow channel remains stagnant. These geometries frame different material-support questions. Primary reference: arching and ratholing.

Review a Hypothetical Comparison

Consider two fictional transparent-model observations. One shows material spanning the opening with an empty region beneath it. Another shows a central emptied channel surrounded by a standing annulus of powder. Calling both simply a “bridge” would discard the difference between an outlet-spanning support and a persistent flow channel.

Keep the Evidence with the Decision

Retain the observed location, inventory level and sequence leading to the interruption. A drawing should distinguish opening, channel and surrounding material; do not infer an unseen internal shape from intermittent dose weights alone. Keep the material state and storage history with the observation so the responsible specialist can identify what evidence is still missing.

This taxonomy does not select an outlet size or establish which flow pattern a production vessel achieves. Discharge can fail for reasons beyond these two ideal descriptions, and an unsafe inspection must never substitute for a suitable engineering assessment. Use the defined geometry to sharpen the supplier question. No invented observation is presented as a confirmed HM incident or a remedy for an installed hopper.

Does the obstruction span an outlet or persist as a channel through stagnant material?

This blank worksheet is for your own project. It contains no H M machine trial result.

Customer Questions

Primary References

These references support the technical principles discussed in this guide. The worked examples and review questions are educational.

• Primary reference: arching and ratholing
• Reference from hmpharmamachines.com