Name: Fuz
Status: Student
Grade: 9-12
Location: MN
Country: United States
Date: March 2008
Question:
In which Industries do powder explosions present a
problem? How are the risks reduced?
Replies:
Perhaps the most famous is in agriculture, where grain dust is an
ever-present fire hazard. My own experience is in the pharmaceutical
industry where fine crystals mixed with solvent can make a severe explosion
hazard.
Hope this helps,
Burr Zimmerman
Fuz -
Any processing that produces a lot of dust - coal dust, flour dust, sugar
dust - has a potential for explosion. Just recently a sugar factory had a
major explosion. The problem comes from the amount of surface area that is
available for a reaction (oxidation... fire). A brick of coal has much less
surface area to be involved in a reaction than the same amount of coal
crushed into a powder. The finer the powder, the greater the surface area.
The greater the surface area, the faster the reaction. The burning brick of
coal release the same amount of heat energy as does the like mass of dust,
but it does so at a slower rate. It is a fire as compared to an explosion.
To mediate the problem plants do such things as wetting the material to avoid
dust in the air, injection the processing environment with an inert gas, and
designing machinery with materials that are unlikely to cause a spark.
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