MISSISSIPPI STATE, Miss. — As if farmers need one more thing to worry about after struggling to harvest much of the state's crops in wet conditions, they now need to be extra cautious when drying their grain in bins.
Herb Willcutt, safety specialist with the Mississippi State University Extension Service, said burners intended to dry grain in bins can cause fires when not maintained or used properly. He said Arkansas reported three bin fires in three weeks as farmers tried to dry their crops.
"Grain bin fires rarely occur, but they can happen when conditions include high humidity and wet grain, and farmers try to rush the dryer," Willcutt said. "Fires can be caused by poor housekeeping of the bins, failure to clean beneath floors, poorly maintained burners and other equipment, and operating the burners at too high a temperature in an attempt to dry grain faster.
"When a full 22,000-bushel rice bin and its contents catch fire, there will be substantial loss of grain and equipment, plus it will require tremendous effort to extinguish the fire," he said.
He said trash beneath the floor or gas released from the supply system or by spoiling grain can be ignited by a spark or flash from the burner. To prevent fires, clean bins and the floor beneath them after each filling. Check burner controls for proper operation before drying grain and every 12 to 24 hours during operation. Also, manage grain so it does not spoil in storage.
"Crusted or caked grain should have been dried to a safe storage moisture before being left in a bin," Willcutt said. "Safe storage moisture depends on the grain being stored, and it is about 12 percent for rice and soybeans and as high as 15 percent for corn."
Willcutt encouraged producers to stir the grain to create moisture uniformity and to be aware that grain may "sweat" and get out of condition as temperatures change during storage.
"Use the fan system to dry and cool the grain anytime grain temperature is 10 degrees above the average daily temperature," Willcutt said. "Use cool, dry fall weather to your advantage, and do this on days when humidity is below 60 percent and temperatures are more than 10 degrees cooler than the grain.
"Be sure to operate the fans until the entire grain bin is completely cool. Failing to do so will result in higher moisture grain on the top of the bin that may spoil quicker," he said.
Producers normally don't need to operate the burner when cooling the grain unless the grain is very high in moisture.
If a fire does occur, Willcutt said, farmers should never enter a smoldering or burning grain bin or one that has been on fire, and they should turn the burner and fan off immediately if a fire is suspected. Protect nearby bins and equipment from spreading flames. Wet grass with a hose, move equipment, protect fuel lines and sources, and remove combustible materials from the area.
"Empty grain into trucks or other bins, watching closely for smoldering grain or trash. Extinguish fires with carbon dioxide fire extinguishers where possible," Willcutt said. "Dump any burning grain onto the ground and douse it with water. Spraying water into a bin of grain will cause the grain to swell and may push out the sides of the bin."
Mississippi farmers have dried grain successfully in bins for years, and this year should be no exception. However, Willcutt urged growers to be extra careful drying more grain than usual since grain is wetter and humidity is higher than average.
Bonnie Coblentz writes for Mississippi State University Ag Communications.