The dust generated during manufacturing or industrial processes is a proverbial ticking time bomb that can cause catastrophic damage to both equipment and personnel. Seemingly harmless materials, such as sawdust or grain dust, can combust spontaneously if exposed to the right conditions.
For many factories and processing plants that generate dust, it’s a matter of “when,” not “if,” they will experience an explosion event. Read on to learn more about dust explosions, why they occur, and how you can safeguard your facility.
What are Dust Explosions?
Explosions happen when a containment vessel ruptures due to the oxidization of dust. If you think back to your high school physics class, you’ll remember the “fire triangle,” or the three factors that are necessary for a fire:
- Fuel (dust)
When these three elements combine in sufficient quantities and concentrations, they can cause rapid combustion or deflagration. For an explosion to occur, two additional factors are necessary: confinement and dispersion. They make up what’s known as the “Dust Explosion Pentagon.” If any one of the five aspects of the pentagon is not present, an explosion cannot happen.
The most damaging part is not the primary explosion but rather a secondary catastrophic one. When the first explosion occurs, it can release a significant amount of additional dust into the air, thereby causing a chain reaction due to the increased concentration and quantities expelled into the atmosphere. The result is a much more powerful explosion that has led to many deaths and costly equipment damage.
What Industries Tend to Have the Most Frequent Dust Explosions?
While all dust producing or processing industries can have dust explosions, a recent NFPA study entitled “Variables Impacting the Probability and Severity of Dust Explosions in Dust Collectors” (Dec 2020) indicates:
“Based on the collected data, the quantitative analysis showed that the most frequent type of dust that was involved in the explosion during the last 10 years was wood dust. It is also the type of dust with the highest number of injuries and the most extensive property damages. The qualitative analyses showed that friction sparks and self-heating are the primary causes of ignition, whereas ineffective housekeeping and design problems of the dust collection system are the biggest contributing factors for the occurrence of the explosion events.”
Dust Explosion Prevention Standards
OSHA has increased their monitoring of dust-producing industries and determined that plants need to have third-party testing labs measure representative samples to determine the explosive nature of their products.
They are using the NFPA 654: Standard for the Prevention of Fire and Dust Explosions from the Manufacturing, Processing, and Handling of Combustible Particulate Solids” as guidance to supplement their General Duty Clause enforcement procedures.
How Do Explosion Doors Help Mitigate Explosions?
Explosion doors will open at a preset and factory-calibrated pressure that is well below the pressure point that will cause a containment vessel to burst. This helps create a dust explosion-proof scenario while eliminating the “confinement” aspect of the Dust Explosion Pentagon mentioned above. The doors allow pressure to relieve itself before it builds up enough to cause a catastrophic explosion.
Explosion Doors from Smart Machine Technologies
Smart Machine Technologies have engineered a proprietary explosion door to help mitigate or solve dust explosions better than the competition. Our doors employ a pre-loaded spring relief and magnet mechanism that allows for superior reusability and reliability. They can open at pressures well below membrane-style (burst disks) overpressure devices.
Our top explosion doors also feature the following benefits:
- High-temperature designs from -65F to 1,000F
- Aluminum, stainless steel, and carbon steel door frame with aluminum or stainless steel door panels
- Self-lubricating sleeve bearings
- Food-grade door designs
- Dual-purpose design that allows for both pressure relief and an emergency access door with fingertip manual relief
Explosion Doors that Protect Against Dust Explosions
Dust explosions can occur with little to no warning and cause catastrophic damage, injuries, and even loss of life. Improve worker safety and protect your expensive equipment with explosion doors from Smart Machine Technologies.