Below is an excerpt from Purdue University's 2019 Summary of U.S. Agricultural Confined-Space-Related Injuries and Fatalities Report.
When Grain Won’t Flow
Not since the 2009/2010 growing season have we fielded more questions concerning grain that has gone out-of-condition and won’t flow out of storage.
The reasons for out-of-condition grain are no longer important.
Whether it was insufficient drying of the grain, excess foreign material, or a leaking bin roof - the issue now is grain flow.
In some cases, a crusted layer has formed on the surface of the grain or within the grain mass causing a void above the outlets as grain is removed. If the crusted grain then breaks up, the chunks can block the outlets reducing or stopping flow.
In other cases, vertically crusted grain can cling to the walls of the structure or form free standing piles that can involve tons of grain that can collapse without warning.
As is well documented in these annual summaries, there is a direct correlation between out-of-condition grain and increased risk of a worker being exposed to an entrapment situation.
In other words, when a farmer or elevator employee has to “fight” to get the grain to flow out of the structure, there is a strong temptation to by-pass safe work practices and enter the structure in order to make attempts to keep the grain flowing.
If the grain won’t flow, it’s already too late to debate what was or was not done last fall to cause the problem.
The issue at hand is to remove the grain without putting anyone at risk of entrapment.
The following are some steps to consider.
They may not be the most profitable options, but are intended to keep everyone safe.
1. Never enter a bin where there is evidence of crusting on the surface or within the grain mass. If grain is removed from the structure and the surface has not flowed inward – stay out! This is a clear sign that crusting is present and a void has formed over the outlet.
2. If there is any signs that the grain is or has gone out-of-condition, it needs to be removed immediately. The condition of the grain will not improve if left in storage, and will only become worse. As warm weather arrives, biological and insect activity will increase, leading to even more spoilage.
3. Perform all observations or unplugging effort from outside the bin, at the top access hatch. Again, if there is evidence of crusting, spoilage, or excessing heating – stay out! The risk is too great. In some cases, long pipes, rebar, or other probes can be inserted into the grain mass to break up crusted grain or trash that is plugging the outlet. Watch out for overhead power lines when handling these long probes.
4. If the grain has become so crusted that it cannot be removed according to the bin manufacturer’s recommendations, contact a professional grain salvage service that has the experience and equipment to break up and remove out-of-condition grain. These services are not inexpensive, but can save lives.
5. Do not cut open the side walls of a bin without consulting the manufacturer. Cutting into a bin could damage the structural integrity of the bin, or result in uneven loading that causes the structure to fail and collapse.