For most people, a layer of dust accumulating in a building might sound harmless. However, certain types of dust particles can lead to explosions with devastating consequences. We call this material combustible dust, and it poses a major, often hidden danger to industrial buildings and their occupants.

This past summer, staff from FSC in SFPE’s Mo-Kan Chapter visited Fike Corporation at their Blue Springs headquarters to learn more about combustible dust explosions and emerging technology designed to protect against them. Combustible explosion testing and preventing is this company’s specialty, so we were in the right place to learn about this topic!

Before sharing the key takeaways from this visit, it’s important to understand 1), what combustible dust is and 2), how it can trigger an explosion.

What Causes a Combustible Dust Explosion?

Combustible dust simply refers to fine particles that can ignite when suspended in air or another oxidizing medium. A wide variety of materials can be combustible under the right circumstances, from plastics and wood to flour and grain. There are five ingredients that cause a dust explosion.

1. Fuel

2. Oxygen

3. Dispersion

4. Confinement

5. Heat (Ignition Source)

Ingredients 1 & 2: Fuel & Oxygen

Fuel in this case refers to the combustible dust itself. The finer and more dispersed the particles are, the more surface area there is to react with oxygen, our second ingredient.

Ingredient 3: Dispersion

Dispersion refers to the dust being spread out in the air, sometimes referred to as a dust cloud. This can occur while the material is being handled or transported, often in a manufacturing process. The combination of the fuel, the oxygen, and dispersion of particles greatly heightens the risk of an explosion.

Ingredient 4: Confinement

Confinement in enclosed spaces, such as a room, machinery, or silos increases the risk – not only because it’s hidden, but also because it increases the pressure and intensity of the explosion.

Ingredient 5: Ignition Source

Finally, there’s the ignition source. Most of us imagine an ignition source as a spurt of fire, but it can be as small as an electrical spark or a hot surface.

How Can Combustible Dust Incidents Be Prevented?

Past instances of combustible dust explosions have been catastrophic, such as the Imperial Sugar Refinery explosion in 2008, which claimed 14 lives and injured 38 people. With lives at stake, building owners can’t afford to leave their facilities prone.

There are many ways to prevent these types of explosions, such as regular dust removal, employee training, and implementing explosion protective systems. This is where Fike’s products shine, and we received a first-hand demonstration of this technology during five combustible dust explosion tests with explosion protection products manufactured by Fike.

Members of FSC’s fire protection and code team visited Fike’s remote testing facility, where their staff demonstrated controlled explosions replicating real industrial processes. The testing site serves as both a research and application testing ground, while supporting the development of their products. After witnessing a few demonstrations, we listened to Fike employees give presentations on dust hazard analyses (DHA) and explosion protection systems.

Dust Hazard Analyses

One prevention method Fike’s presenters shared was conducting a dust hazard analysis (DHA). The purpose of a DHA is to help building owners identify if and how their facilities and processes could result in a dust explosion. The process begins by identifying potential hazards and assessing risks using a risk ranking matrix. The expert or consultant performing the DHA will analyze the facility’s processes and materials in detail to determine whether a hazard exists at all. From there, they can measure the potential impact of an explosion and recommend the best systems and safeguards for a facility.

Explosion Protection Systems

Another presenter talked about Explosion Protection and went into detail about explosion protection systems that Fike produces and how to pick the right protection product for your specific application. Here are a few of the systems they shared with us:

Explosion Venting (Vent Panels & Flameless Venting)

Vent Panels: These are ideally located outside, or if they’re inside, they’re near an external wall to direct pressure and flames outside. When installed onto a piece of industrial equipment, vent panels are engineered to burst at a specific pressure level and provide a pathway for the rapid release of pressure when a dust explosion occurs in a confined space. This prevents the buildup of additional pressure that could cause catastrophic equipment failure or secondary dust explosions.

Flameless Venting: A flameless explosion vent device is placed over the vent panel. It has a flame filter to extinguish fire while the vent panel redirects the explosion pressure.

Explosion Suppression

These systems automatically detect and chemically suppress an explosion in its earliest stages before the explosion causes serious damage. They are used in locations where explosion venting or flameless venting isn’t a safe option, or when the equipment isn’t big enough to support vent panels.

Explosion Isolation

Explosion isolation products are safety devices that stop a fireball or pressure wave from spreading through pipes or ducts during a combustible dust explosion. They act like barriers, keeping the explosion contained to one area and protecting workers, equipment, and other parts of the facility. This helps limit damage and improves overall plant safety.

Choosing the System Right for You

There are several different factors to consider when choosing any of these systems. How much space is available? Can the flames be safely vented to the outdoors? If the flames can’t be vented to a safe location, flameless explosion vents may be installed.

Another factor to think about when choosing a protection system is how important it is for the system to be started back up as quick as possible or not – some systems like explosion venting can be reset or replaced quickly if there are backup panels on hand; others may take more time to reset.

Final Thoughts

Combustible dust incidents pose serious safety risks and challenges for a wide range of industries. As engineers involved in multiple disciplines, it’s important to us that we stay engaged in wider industry conversations, especially in areas like this that lie outside our area of expertise in the fire protection sector – at least for now.

We hope you enjoyed reading our takeaways from the 2024 SFPE Conference as much as we enjoyed attending! This was a great opportunity to expand our knowledge in a new area. Staying current with new risks and technologies ensures we can deliver effective, compliant solutions while making sure we satisfy our clients’ evolving needs.