· Mechanical friction and collision
· Electrical spark
· Hot surface
· Electrostatic discharge
· Dust spontaneous combustion
Explosion range: The dust cloud can occur explosion only in a certain concentration of dust . This concentration range is the explosion range.
Lower explosion limit: Minimum dust concentration that can explode.
Upper limit of explosion: the magnitude is nearly 100 times of the lower explosion limit.
· Dust type
The explosive parameters of grain dust are very close. The explosion pressure of grain dust is generally less than 1MPa. The rice starch and corn starch explosion index is relatively high, up to 19MPa.m / s and 16MPa.m / s.
· Particle size distribution
When the dust particle size reaches 250μm or more, it is not easy to form the dust cloud. When the dust particle size is less than 75μm, it is easy to form the dust cloud.
· Moisture content
When the dust contents more than 10% moisture, it is not easy to explode. When the dust content less than 5% moisture, it is easy to explode.
Explosion pressure: Pmax
Explosion index: Kst
Minimum ignition energy: MIE
The minimum ignition temperature of the dust layer: MIT-L(AIT)
Dust cloud minimum ignition temperature: MIE-L
Lower explosion limit: (LEL,MEC)
Limit oxygen content: LOC
Dust resistivity: DR
Dust explosion usually occur in processing line of aluminum powder, zine powder, plastic powder, dyestuff, corn flour, flour, milk powder, medicine intermediate, coal dust and wood bits ect.