Powder Dusts Flashcards
Become an expert on powder dusts
What size particle qualifies something to be dust?
60 Mesh or 0.246 mm in particle diameter
Do metallic powders fall under the category of powder dusts?
No, they would fall under the category of “hazardous materials” (Aluminum or iron powders)
What is A hazard classification?
Explosive. This contains aluminum, magnesium, titanium, and dusts that contain 20% of these three metals or more by weight.
What is the value of LR?
LR is the experimental explosiveness factor, or how explosive it was during an experiment.
What is the Value K?
The calculated explosiveness factor. 0 is C - no flammability. Less than 0.1 is B3, small risk of flammability. 0.1-2.0 is B2, or medium risk of flammability. 2.0 or more is B1, or high risk of flammability.
What is the K value for aluminum flakes and fine particulate?
Flake - 27.8 and Dust - 3.7 (Explosive)
What is the K value for Zinc?
0.0013 - Low hazard for flammability
What is the K value for Copper?
- No flammability.
What is the K value for stainless steel?
The information for K is not known but receives a B2 rating for medium flammability hazard.
What is the K Value for epoxy resin?
29.2, but receives a flammability hazard of B1 - High risk for flammability but not explosive.
All passageways that could contain powder dusts should be what?
Grounded.
What is the Denso combustible dust standard?
DAS 110300.
Awareness of what is usually a key factor in duct explosion/fire incidents?
According to OSHA, awareness of the dangers of combustible dusts is one of the main issues after an incident.
What are the 5 elements of the dust explosion triangle?
1) Combustible Dust (fuel) 2) Ignition Source 3) Oxygen in air 4) dispersion of dust particles in sufficient quantity and concentration 5) Confinement of the dust cloud
What are the two phases in a dust explosion?
The initial explosion, causing particles to go into the air. The second explosion is the most dangerous, due to the loose particles floating around in the air.
