Which dusts are likely to explode?

The dusts that may explode are coal dust, flour, wood flour, sugar flour, corn flour, potato flour, dry milk powder, aluminum powder, zinc powder, magnesium powder, sulfur powder and so on.

When the dust reaches a certain concentration, first of all, the suspended dust under the action of the heat source to rapidly distill or gasify and produce combustible gases; secondly, combustible gases mixed with air and combustion; once again, is the dust combustion of the heat released to heat conduction and flame radiation to the nearby suspended or blown up the dust, the dust by the heat of the gasification so that the The combustion cycle continues.

With each cycle one by one, the reaction speed gradually accelerated, through the intense combustion, and finally formed an explosion. This explosive reaction as well as the explosion flame speed, explosion wave speed, explosion pressure, etc. will continue to accelerate and rise, and jump development.

Combustible dust explosion should have three conditions, that is, the dust itself is explosive, dust must be suspended in the air and mixed with the air to the explosive concentration, there is enough to cause the dust explosion of the ignition source.

The main hazards of dust explosion

(1) has a strong destructive. Dust explosion involves a wide range of coal, chemical, pharmaceutical processing, wood processing, food and feed processing and other sectors have occurred from time to time.

(2) easy to produce a secondary explosion. The first explosion of the air waves deposited in the equipment or dust on the ground blowing up, in the short period of time after the explosion in the center of the explosion will form a negative pressure, the surrounding fresh air from the outside to fill in, the formation of the so-called "return to the wind".

Mixed with the dust raised, in the first explosion of the residual fire ignited by the second explosion. The second explosion, dust concentration is generally much higher than the first explosion, so the second explosion is much more powerful than the first.

(3) can produce toxic gases. One is carbon monoxide; the other is the explosive (such as plastic) own decomposition of toxic gases.

Reference: Baidu Encyclopedia - Dust Explosion