In northwest Iowa, Plymouth County officials responded to a grain bin explosion that injured two workers last week. It took nearly an hour for fire teams to put out the flames.
As it happens, it takes the stars aligning to get a grain bin to blow up.
A series of five events need to take place: The first is dust, normally caused by grain moving, which is the fuel in the bin and all it takes is a sheet of it as thin as paper; then that dust needs to disperse; the dust needs ignition or a spark, which could be a mechanical or human cause; it has to be in an enclosed space; and it has to have oxygen.
It takes all five of those things to happen for a bin to light up according to ISU Assistant Professor Gretchen Mosher, “It usually occurs in two phases, the first one is a small amount of dust that ignites, then when that dust ignites, it creates another cloud of dust, which often causes a secondary explosion. It is that secondary explosion that often does or causes the injury or fatality. It can destroy a facility, it can flatten it to the ground.”
It may seem as though there have been more grain bin explosions in the last year but Mosher says they have been declining since the 1980s. From 1980-1989 there were an average of 20 grain elevator explosions per year according to the U.S. Occupational Safety and Health Administration. From 2000-2009 the explosions averaged just under eight. Iowa has just been handling a lot more grain the past few years.
A collaboration of Iowa State University and Purdue University funded by the Department of Labor has started training programs to deal with grain dust. A lot of it is made from brittle, dry grain breaking off into small pieces as it’s moved.Mosher says there are a couple measures that help limit explosions, like trying to keep the dust down from dispersing and also being careful. If the turbulence is reduced from siphoning grain to different bins or from truck to the dump pit or if it’s moved in an open air environment that can reduce the risk of a grain explosion.
Mosher says there are a couple measures that help limit explosions, like trying to keep the dust down from dispersing and also being careful. If the turbulence is reduced from siphoning grain to different bins or from truck to the dump pit or if it’s moved in an open air environment that can reduce the risk of a grain explosion.Mosher says, “Good housekeeping, daily housekeeping, daily trying to contain that dust in the facility will do more than just about anything else.”
A grain dust training session along with other educational sessions will be held this summer.
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