Commonly begins with the ignition of a fuel that burns very rapidly.
Produces a large and sudden release of gas
An explosion need not involve a fire.
When a container bursts from increased internal pressure, sudden release also called an explosion.
Secondary dust explosions, due to inadequate housekeeping and excessive dust accumulations.
Secondary dust explosions due to propagation through interconnected ducts, chutes, conveyors, …etc.
SECONDARY EXPLOSIONS ARE THE MAIN THREAT TO PERSONNEL AND PROPERTY!
Flame Speed 30 ft/s
30 ft/s (9m/s)
Pressure Wave 1100 ft/s
1100 ft/s (335 m/s)
•Ingredion (National Starch)
•International Flavors and Fragrances
Sugar •Western Sugar•American Sugars•Imperial Sugars•American Crystal Sugars，Dairy Products (powder) •Kraft Foods•AC Humco•Nestles
Dust Collectors Reactors
Bins, Hoppers, Silos
Dryers (Spray, Fluid Bed, Rotary)
Mills, Grinders, Pulverizers
Deflagration Pressure vs. Time
ST Classification:ST-1, ST-2, ST-3; Rst Value:1-200;201-300,301-above
Example:Pittsburgh seam coal has a Kst of 129 bar-m/sec,making it an ST-1 dust Applicable Codes (USA)