When material transfers from a conveyor belt or hopper to a conveyor belt, it is crushed under its own weight and exposed to airflow, creating opportunities for dust. Dust creates a harmful environment for those working around it, environmental concerns, and increased scrutiny from neighbors. OSHA and MSHA have targeted efforts accompanied by steep fines to reduce dust. Most facilities don’t fully understand the underlying issues causing dust and therefore, don’t know how to properly solve it. Many facilities focus on dust suppression and collection which are advantageous but it is more beneficial to focus on dust containment. Dust should be controlled at its source of creation. Control dust at the transfer point by controlling the air associated with the material being transferred. By controlling the air, dust is therefore controlled.
Root Causes:
- Influx of air as the transfer point loads with material
- Material degradation increases small fines
- Poor transfer point design for current production expectations
Best Practices:
- Support the belt the entire length of the chutewall so it doesn’t sag away from skirting
- Protect rubber skirting with an abrasive-resistant steel wearliner
- Install belt skirting to seal air
- Utilize suppression and collection only after containment has been achieved
- Slow the exiting air velocity to under 200 FPM with a dust curtain
/topic-image-gallery_new-dims_dust.png "airborne dust around a belt conveyor")
/topic-image-gallery_new-dims_dust-outside.png "Dust floating all around a stacker conveyor dumping into a pile of material.")