Board of Directors Meeting – Day 3
September 24, 2020 at
Increased production underscores need for combustible dust control
To meet an increasing global demand for their product, Canadian wood pellet mills are using new and emerging technologies. As producers turn to automation and faster machinery, they need to be aware of what this means for the health and safety of their workers. One concern is that along with an increase in pellet production comes an increase in accumulated dust that can explode if not controlled.
Unlike most manufacturers, for whom dust is a by-product of their processes, pellet mills use sawdust and wood shavings as their raw material. Pellet producers crush wood waste materials in hammer mills, then dry them to a moisture content of 4 to 6 percent in sawdust-drying machines. Large quantities of this combustible dust are delivered, stored, conveyed, dried, and pressed into pellets. To avoid a catastrophic explosion, it is essential that pellet producers control and manage combustible dust.
Best practices for preventing fire and explosions in wood pellet production:
- Remove foreign metallic materials in the raw materials. This is done using Permanent Magnetic Drums or other magnetic equipment located in the duct that carries dust out of the drying machine. Any metallic materials must be removed from the dust before it goes into wood hammer mills, pellet machines, or ducts into storage silos.
- Check pellet machines for signs of wear. This includes roller shells, dies, bearings, and anywhere else friction from worn parts could overheat.
- Monitor pellet temperature automatically. A high temperature warning system must be installed at the discharge gate of wood pellet machines.
- Use dust collection systems throughout the entire production line. Dust build-up must be cleaned from all horizontal and vertical surfaces on a scheduled basis. Surfaces should be cleaned in a manner that minimizes the potential for generating dust clouds.
- Remove all elements that can cause fire or explosion. Some examples include, cutting and welding flames, electrostatic discharge sparks, impact sparks or direct fired space and process heating.
- Reach out to your networks to find a qualified person who can identify risks and the corresponding controls. Someone with specific knowledge in assessing combustible dust fire and explosion risk processes, can evaluate your current handling practices, equipment, fire extinguishing systems, and other efforts.
For resources on preventing combustible dust explosions, visit worksafebc.com/combustible-dust.
For more information, visit our website www.worksafebc.com/en