Can dust cause fire explosion?
Can dust cause fire explosion?
When combustible dusts ignite, there are often two explosions known as primary and secondary explosions. The primary dust explosion is the first explosion. It occurs when there is a dust suspension in a confined space (such as a container, room, or piece of equipment) that is ignited and explodes.
Why does dust explode so violently if ignited?
If a concentration of dust is too low, there is not enough of it present to fuel an explosion. If the concentration is too high, there is not enough oxygen to support combustion. The ignition causes the dust to combust quickly—a process called deflagration that creates a wave of high air pressure.
How does dust cause explosions?
Dust explosions are the result of high concentrations of combustible dust particles rapidly combusting inside an enclosed space. This will mix the dust with the oxygen in the air, which will make the explosion bigger, and potentially fuel a second dust explosion – or even several.
Why is dust flammable?
Dusts have a very large surface area compared to their mass. Since burning can only occur at the surface of a solid or liquid, where it can react with oxygen, this causes dusts to be much more flammable than bulk materials.
How can we prevent dust explosions?
Help Prevent Dust Explosions
- KNOW THAT MOST DUSTS ARE COMBUSTIBLE.
- PROVIDE ACCESS TO ALL HIDDEN AREAS OF YOUR PLANT.
- REGULARLY INSPECT FOR DUST BUILDUP.
- CLEAN AT REGULAR INTERVALS.
- MOVE DUST COLLECTORS OUTSIDE.
- ENSURE ELECTRICAL WIRING AND EQUIPMENT IS APPROVED FOR USE IN YOUR DUST HAZARD CONDITIONS.
What is a combustible dust explosion?
Combustible dusts are fine particles that present an explosion hazard when suspended in air under certain conditions. A dust explosion can cause catastrophic loss of life, injuries, and destruction of buildings.
How does dust explode?
How powerful is a dust explosion?
Determining the minimum explosive concentration or maximum explosive concentration of dusts in air is difficult, and consulting different sources can lead to quite different results. Typical explosive ranges in air are from few dozens grams/m3 for the minimum limit, to few kg/m3 for the maximum limit.
How does dust explosion work?
How does dust explosion occur?
Dust explosions are the result of high concentrations of combustible dust particles rapidly combusting inside an enclosed space. When mixed with oxygen, these fine particles can be ignited when coming into contact with a spark, metal ember, cigarette butt, or other ignition source.
What happens when a dust collector catches on fire?
Without explosion relief venting, a dust collector fire can cause a rapid increase in pressure inside the enclosed space. Then, with no safe outlet, the growing pressure can damage the dust collector or even the entire facility. So it puts lives at risk. NFPA 68 specifies what explosion venting must do to meet standards.
What is NFPA 68 for dust collector explosion venting?
According to NFPA standards, explosion venting is a key part of dust collector safety. NFPA 68, the Standard on Explosion Protection by Deflagration Venting, lays out these guidelines. Dust collector explosion venting, also called deflagration venting, allows pressure to safely escape during a fire.
How are dust volumes determined in Automated blasting?
Dust containment requests are associated with cabinet or automated blasting processes. Air volumes are determined based on the velocities necessary through open areas to prevent dust from escaping the enclosure. Dust containment requests are associated with cabinet or automated blasting processes.
How is the blast deflector plate on a dust collector?
This plate will usually face the vent at an angle of somewhere between 45 degrees and 60 degrees. The blast deflector plate must take the full force of the vented explosion and redirect it. Dust collectors located indoors usually have ductwork that vents to the outdoors.