Combustible Dust Safety for Silo Dust Collectors

Start With Dust Data

Review the safety data sheet but do not assume it contains all explosion parameters. Representative testing may be needed for explosibility, minimum ignition energy, maximum pressure and rate of pressure rise.

Particle size, moisture and process changes can alter behaviour, so test material should represent the operating dust.

Hazard Assessment

Identify where dust clouds and layers occur, possible ignition sources, connected vessels and occupied areas. Review normal operation, startup, shutdown, maintenance and foreseeable upset conditions.

Electrical area classification is only one part of the assessment. Mechanical sparks, hot surfaces, static discharge and smouldering material also require review.

Protection Concepts

Depending on the hazard and location, an engineered system may include prevention, explosion venting or suppression, flameless devices, isolation and safe discharge zones. These measures must be compatible with vessel strength and connected equipment.

Grounding and conductive media can reduce certain static risks but do not replace explosion protection when an explosible atmosphere can form.

Operational Controls

• Prevent dust accumulation through housekeeping
• Inspect bonding and grounding
• Control hot work and ignition sources
• Maintain relief, isolation and suppression devices
• Train operators on alarms and emergency response
• Manage changes in raw material or process rate