Dust Explosions - Substances, Critical Temperatures and Concentrations
Basic rules to observe for dust to be capable of causing a dust explosion:
- The dust must be combustible
- The dust must be airborne
- The dust must have a size distribution capable of flame propagation
- The dust concentration must be within the explosive concentration range
- An ignition source with high enough temperature must be present
- The atmosphere must contain sufficient oxygen to support and sustain combustion.
Critical temperatures and concentrations:
| Substance | Ignition Temperature of Dust Cloud (oC) | Minimum Explosive Concentration (oz/ft3) | Relative Explosion Hazard |
|---|---|---|---|
| Alfalfa | 460 | ||
| Aluminum | 650 | 0.045 | Severe |
| Al-Mg alloy | 0.02 | Severe | |
| Cereal grass | 550 | ||
| Chromium | 0.23 | Strong | |
| Coal | 610 | 0.055 | Strong |
| Copper | 900 | Fire | |
| Corn | 400 | ||
| Epoxy Resin | 530 | 0.020 | Severe |
| Flax shive | 430 | ||
| Grain dust, winter wheat, corn, oats | 430 | ||
| Iron | 420 | 0.100 | Strong |
| Magnesium | 520 | 0.020 | Severe |
| Rice | 440 | ||
| Silicon | 0.11 | Strong | |
| Soy flour | 540 | ||
| Tin | 630 | 0.190 | Moderate |
| Titanium | 460 | 0.045 | Severe |
| Uranium (finely divided metal dust) | 20 | 0.060 | Severe |
| Wheat flour | 380 | ||
| Wheat straw | 470 | ||
| Zinc | 600 | 0.480 | Moderate |
- missing data not available at the moment
- 1 ft3 = 0.02832 m3= 28.32 dm3 = 0.03704 yd3 = 6.229 Imp. gal (UK) = 7.481 gal (US) = 1,728 Cu.In.
- 1 oz (ounce) = 28.35 g = 437.5 grains = 0.0625 lb = 0.0000279 long ton (UK) = 0.00003125 long ton (US) = 0.000558 long hundredweight (UK) = 0.000625 long hundredweight (US) = 0.004464 stone = 16 dram
Related Topics
• Material Properties
Material properties of gases, fluids and solids - densities, specific heats, viscosities and more.
• Miscellaneous
Engineering related topics like Beaufort Wind Scale, CE-marking, drawing standards and more.
• Risk, Reliability and Safety
Risk, reliability and safety in process control systems.
• Temperature Measurement
Measurment of temperature - probes, sensors and transmitters.
Related Documents
Chimney's Explosion Doors
Recommended size of explosion doors or draught stabilizers in oil fired installations.
Coal - Classification
Classification of coal based on volatile matter and cooking power of clean material.
Firefighting Water - Required Volume Flow
Required water for firefighting.
Fuel Gases - Flame Temperatures
Adiabatic flame temperatures for common fuel gases - propane, butane, acetylene and more - in air or oxygen atmospheres.
Fuels and Chemicals - Autoignition Temperatures
Autoignition points for fuels and chemicals like butane, coke, hydrogen, petroleum and more.
Gases - Explosion and Flammability Concentration Limits
Flame and explosion limits for gases like propane, methane, butane, acetylene and more.
Hazard vs. Flash Points
The flash point of a chemical indicates how easy it may ignite and burn.
Hazardous Areas - European Classification Standard
European hazardous area classification with zones, protection types, temperature codes and codes.
Hazardous Areas - North America Classification
North American hazardous locations classification with classes, divisions and groups
Hazardous Areas - Protection Techniques according European IECEx
Hazardous areas protection techniques - explosion proof, flameproof and intrinsically safe.
Hazardous Areas Protection Techniques for North America
Dust-ignition proof, explosion proof, instrinsically safe and nonincendive protection of hazardous areas.
NEMA Enclosure Standards for Electric Motors
NEMA enclosure standard for electrical motors.
Water Sprinkler Protected Areas vs. Hazard Classification
Maximum fire sprinkler protected area vs. classification and construction.