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Cutting Combine Fire Risk
Thursday, August 1, 2024
filed under: Harvest/Storage
Farming has plenty of challenges. Will there be enough rain for the crop to grow? Will hail wipe out a promising field? And for numerous producers during crop harvest, there’s always another question looming: Will the combine start on fire?
Those are all valid concerns. Sunflower is one crop that can present a real fire hazard during harvest. Because it’s an oil-based crop, fine fibers from sunflower seeds pose a constant fire hazard, especially when conditions are dry.
NDSU Extension farm and ranch safety coordinator Angie Johnson says combine fires can occur at any time with the right conditions. Sunflower, however, poses a greater risk because of the large volume of dust and particulate it produces during combining.
“Research by South Dakota State University ag engineers several years ago confirmed that the white portion inside the stalk, known as the pith, breaks down into very small, tiny particulate pieces with large surface areas that easily get sucked into the fan that is pulling air through the machine’s radiator to cool down the engine,” Johnson explains. “That pith dust and particulate easily sticks to engine and exhaust components and can ignite when it comes into contact with the turbocharger and exhaust system of the combine.”
Combine fires during sunflower harvest have been a problem for years, and those fires have even scared some growers enough to where they’ve removed sunflower from their crop rotation. That was enough to prompt the South Dakota Oilseeds Council to seek a solution. In 2012, the council approached South Dakota State University agricultural engineer Dan Humburg for help.
“They said, ‘This is the limiting problem for sunflower and for many producers,’” Humburg recalls. “They told me they had producers who refused to grow sunflower because they didn’t want to risk burning up their combines. It wasn’t worth the risk to them. The council made it clear that they would support it with some dollars for research if we would commit to doing some work on it.”
Humburg remembers his first thoughts back then: producers just needed to do a better job of keeping their combines clean. He thought that would eliminate the fire danger. But, he quickly learned there was more to it.
“Producers we met with explained that when the conditions were bad, they could figure out a threshold that they could operate at,” says Humburg. “For one grower, it was the indication from his instruments of a percent of rated engine power. He knew if he was operating at 75% of what the engine was capable of doing the engine’s full power, he might not have a fire. But if he pushed that to 77%, he would have a fire almost immediately.
“Another grower explained he didn’t gage it by percentages, but rather by fuel consumption. His instruments were telling him how much fuel he was consuming, and he knew if he crossed a certain line, he would have smolders.”
That kind of feedback told Humburg and his team the fire risk was related to temperature at the exhaust system. And that, in turn, led them to develop add-on kit prototypes that filter the air hitting the exhaust system. That prevents the dust from being ignited in the first place.
The National Sunflower Association joined with the South Dakota Oilseeds Council to fund Humburg’s research.
Humburg retired from his job at SDSU in 2016, but he continues to address this issue through the production and sale of his FireStop combine fire prevention kits. The concept today is exactly what he and his team first came up with in 2012. The hardware system is added to the combine and prevents the ignition of volatile aerosol dust near hot exhaust components.
Humburg says many of his clients these days are repeat customers, people who purchased a kit years ago and now have purchased a new combine and don’t want to go through a harvest without a FireStop installed. He has installed kits in machines throughout North and South Dakota, and has sold them to growers in Nebraska, Montana and Canada as well. Humburg says while nine out of 10 sales are to sunflower producers, he’s had farmers purchase them to cut down on fires during canola, peas, safflower and soybean harvest.
You can learn more about Humburg’s kits and specific models and place an order at www.harvestfires.com. Humburg also welcomes emails and phone calls to help producers figure out what might work in their situation. You’ll find contact information on that website as well.
Humburg knows his harvest fire kits aren’t the only way to prevent combine fires, and even with his system installed, he urges producers to take other steps to prevent combine fires.
The National Sunflower Association has an entire section on its website where producers can share what’s worked for them in reducing their risk of combine fires (https://www.sunflowernsa.com/growers/Surveys/Combine-Fire-Responses/). Producers from the Dakotas to Texas, Canada and Wisconsin all echo the same advice: “Keep the combine as clean as you can and blow off the machine daily.”
NDSU Extension farm and ranch safety coordinator Angie Johnson says that’s good advice – and she adds a few more tips for producers:
• Pre-operational checks. Take time to walk around the combine before the start of each day during harvest season. Use an air compressor or leaf blower every day when the machine is off and cooled down, to remove dirt, dust, chaff and other plant reside that has accumulated. Always wear hearing protection, eye protection and respiratory protection, such as an N95 mask, when using an air compressor or leaf blower to remove plant dust and residue. While blowing off residue, look in high-risk areas, such as the engine and engine compartments, hydraulic pumps and pump drives, gear boxes, batteries and cables. When cleaning, take time to look for any issues that require repair, such as leaking hydraulic hoses that can be a perfect place for chaff to stick and build up, creating an easy fuel source for a fire.
• Service the machine daily. Take time to do this, based on the combine’s operator manual. Grease and lubricate bearings and chains and continue to look for areas with excessive wear or damage.
• Watch for wiring issues. Today’s combines are controlled by many sensors and electrical components that are extremely complex. Take time to glance through wiring systems to see where wires appear to be unrestrained or if wires appear to be damaged from rubbing or contacting moving parts.
• Use an infrared thermometer. Hot bearings are a combustion source. To check the bearings, warm up the combine before taking it to the field and use an infrared thermometer to determine the operating temperature of your combine’s bearings. Safely open the combine’s shields, including the header, and from a safe distance, point the infrared thermometer at a bearing to read the measured temperature. If the thermometer measures a bearing temperature that is much higher than others, it is time to replace that bearing, as it may be worn or damaged. Infrared thermometers are inexpensive (less than $50) and can be found at many hardware and farm stores.
• Install an air intake kit. An air intake kit allows clean air found above the combine’s “dust cloud” to enter the combine’s air intake screen, instead of taking in the dusty, dirt-filled air produced from harvesting the crop. Take the time to consider an option that will work best for you and your combine.
• Avoid combining during fire danger conditions. Believe it or not, harvest conditions can be too good, meaning it can be too warm and dry to combine your crop. Relative humidity values are low in the fall, increasing the risk of fire, especially in the late afternoon hours. Keep an eye on outdoor air temperature, relative humidity and wind speeds. As hard as it is to shut down for the day when conditions are favorable for harvesting, shutting down when temperatures are hot, dry and windy could prevent you from losing your combine to a fire. For North Dakotans, find out if your area is in a fire danger zone by visiting: https://ndresponse.gov/burn-restrictions-fire-danger-maps. If you must continue combining, take extra precaution and clean your combine more frequently.
• Carry two, fully charged fire extinguishers. Ideally, you should have two 20-lb, charged fire extinguishers on your combine. Have them ready and operational and review with workers how to use them when needed. Call 911 immediately to get your closest fire department on scene.
• Create a soil perimeter. If you choose to harvest during high wind and temperature conditions, make a tillage pass around the perimeter of your field to prevent the possibility of a fire spreading to other areas on the landscape should a combine fire occur.
“Good machine maintenance, cleaning and monitoring can help reduce the incidence of combine fires during crop harvest,” Johnson affirms. “Make farm safety a priority on your farm this fall. Combines and crops are replaceable; you are not.”
For more information on crop harvest fire prevention, visit www.ag.ndsu.edu/ publications/crops/crop-harvest-fire-prevention-checklist. — Jody Kerzman