Due Diligence

The generation of dust never gives up and can only be fought with diligence.”

It may seem a bit over-dramatic, but the risk of dust explosions in pellet manufacturing plants is serious business and must be treated as such.
Recently, the Wood Pellet Association of Canada (WPAC) released a report that outlines steps pellet mills can take to assess and minimize the risk of dust explosions in their facility and it concluded with the above quote.

Penned by research director Staffan Melin, Determination of Explosibility of Dust Layers in Pellet Manufacturing Plants looks at dust explosions in the pellet industry and outlines a dust management scheme that would eliminate much of the risk at a minimal cost. The report also discusses risk assessment, dust sampling and categorization methods.

In pellet manufacturing plants, cleaning and monitoring dust levels hasn’t always received the attention it deserves, as the priority is usually keeping the plant operating and producing revenue. “Cleaning of floors is a nuisance since the generation of dust never stops but it is as important as regular maintenance of machinery,” states the report.

However, it offers a methodology for evaluating how much dust on floors, girders and beams is acceptable in order to ensure a safe working environment.

While there are published guidelines on the subject, most aren’t specific to the kinds of dust produced in pellet plants, and that’s where the WPAC report comes in. Based on lab testing, the report offers pellet plant operators information to evaluate the necessary safety precautions that need to be taken as it relates to “housekeeping” or controlling dust levels.

According to the report, keeping up-to-date records, using the correct methodology to record dust accumulation and sharing this information with everyone in the plant are key to a successful plan to control dust explosions. “Whoever is assigned the responsibility of controlling the dust level in a manufacturing plant should be equipped with methodology to record thickness of dust accumulation in layers and spaces where dust is continuously suspended in the air. Inspections and recordings need to be done at preset intervals. This should be done every time just before vacuuming takes place.”

A well-kept record of thickness measurements seems to be the best approach, concludes the report: “A well calibrated thickness meter and well-kept record of measurements could eliminate much uncertainty and disputes regarding safe operating procedures and eliminate poorly designed operating equipment and procedures.”

This method also promotes collaboration amongst employees at all levels, keeping the issue of dust explosions and their prevention top of mind. Dust will continue to fall in pellet plants, just as the industry’s diligence towards safety will continue to rise.

John Tenpenny, Editor
jtenpenny@annexweb.com