One of the most energy-intensive practices on your farm is drying grain. As you burn fuel to produce the energy required, you are “burning money.” Unfortunately, there is no single, easy solution to cut such costs. As Gary Woodruff from CSI puts it, “No two farms are the same. There isn’t one best way to dry grain.”
However, the following list can offer suggestions for saving energy, depending on your infrastructure for grain drying and the size of your farming operation.
- Run in all-heat mode
“One thing that’s been around for a long time but is still cost effective is running a portable dryer in the all-heat mode,” says Woodruff, explaining that such a process can save 20-30% in operating costs.In all-heat mode, the grain is heated in the dryer and cooled in the bin. “The advantage is you can come out of the dryer at a higher moisture content, and then you lose one, two, or three points of moisture in the cooling process,” explains Kerry Hartwig of Sukup Manufacturing Co. “Drying those last points takes the most energy.” Efficiency is also increased by running in all-heat mode, because the grain moves more quickly through the dryer. Additionally, better-quality grain is produced in this manner, as rapid cooling of grain may increase stress cracking of corn kernels.
However, all-heat mode does have its limitations. For example, this system does not work on the majority of bins that are larger than 50,000 bushels; this limitation is due to the air requirement ofbetween 1∕3 and ½ cfm of air running through each bushel when the bin is full. For smaller bins, larger aeration fans and more roof vents are required, along with more direct management. “There are better drying systems on the market that don’t require the extra management that all-heat mode requires,” explains Woodruff, “but this is one of the least expensive ways to improve how you process grain on your farm.”
- Buy an all-heat dryer
If you can afford an upgrade and your present dryer isn’t able to run in all-heat mode, consider an all-heat dryer. As Woodruff states, “A new all-heat dryer gives the most capacity, efficiency, and quality for the dollar, even with the bin aeration upgrades required.”
- Upgrade to heat recovery or vacuum cooling
“For larger operations, it will be more efficient for grain to come out of the dryer cool,” according to Hartwig. “That’s where vacuum cooling or heat recovery can make a big difference.”In vacuum cooling, heat given off by the grain as it cools gets cycled back into the drying process. In this manner, the drying air temperature is raised with less fuel required.
Centrifugal, tower, and centrifugal stack dryers also offer vacuum cooling.“With vacuum cooling, you can dry grain with even better efficiency than you can with all-heat drying,” Woodruff explains. “You will spend more money up front, and you’re going to need a pretty good size grain dryer to get that newer technology.”
- Dry grain evenly
“If a dryer dries grain faster in some areas and slower in others, the dryer will overdry grain to make up for the underdried grain,” states Hartwig. “This adds drying cost in extra fuel used and lower grain test weights from overdrying.”
Various systems are available that can help dry grain more uniformly. Sukup’s stacked and single-module dryers utilize a quad-metering roll system: it pulls dryer grain close to the inside of the grain column more quickly out of the dryer, while it leaves wetter grain towards the outside of the column in the dryer for a longer period of time. A grain crossover system is also part of stacked dryers, which takes grain from the top module on one side and moves it to the other side of the bottom module. This inversion of the grain allows it to dry more evenly. Sukup tower dryers make use of a system of grain exchange located halfway down the heat chamber.
GSI’s grain inverters provide another option. Such inverters move all but the outer two inches of grain within the column, eliminating overdried grain and greatly increasing drying efficiency. The warmest grain from the inside of the column is redirected next to the outside of the column, where the wettest grain is found. The wetter grain is dried by the heat of the dried grain, recovering up to 15% of the heat that might have otherwise been lost.
- Run at a higher plenum temperature
As Woodruff describes, “One thing you might not be aware of is that the higher you run your plenum temperature, the more efficiently you dry grain. At the end of the season, farmers will say they are only removing three to four moisture points, so they lowered their plenum temperature to save some fuel. Exactly the opposite happens.”
While drying time is reduced and less fuel is used by running at a higher temperature,the elevated heat can possibly cause more damage. Striking a balance is required. “Each dryer’s airflow and column management is different, so you have to balance efficiency with quality,” Woodruff states. “There will be a maximum best temperature for each type of dryer.”
- Do preseason maintenance
Before the process of drying grain is begun for the season, ensure that the burner is prepared and that there are no obstructions within the columns. During the harvest period, the dryer should be emptied, cleaned, and restarted weekly to ensure that the dryer is at peak performance. Woodruff asserts that “like any other piece of equipment, if you don’t take the time to clean it and keep it in operating mode, you are probably going to reduce your efficiency.”
- Avoid overdrying
Grain must be dried to safe levels of moisture prior to storage. This level ranges from 13-15%, depending on the intended period of time that the grain will be stored. On the other hand, overdrying should be avoided, as going beyond the required level of moisture will require more energy for each percentage point removed, and will offer no benefits for doing so.
- Use a remote monitoring system
A remote monitoring system is one way to avoid overdrying. While each system varies by manufacturer, most systems allow you to use a tablet, smartphone, or other device to monitor all dryer controls as if you were monitoring it in person. “Farmers want to be able to monitor their dryers in the combine, at home, wherever they are,” explains Hartwig.
Some systems, such as GSI’s WatchDog and Sukup’s remote monitoring, , adjustments can also be made remotely.“The only thing you can’t do is start the dryer without being there, because that would be dangerous,” mentions Woodruff. “You can adjust things like the plenum temperature, moisture control setting, and unload limits.”
In addition to avoiding overdrying, remote controls can also ensure that the dryer is not only running efficiently but also that it hasn’t stopped for any reason. Woodruff says that “the average dryer puts 2,500 bushels through an hour. In 10 hours, that’s 25,000 bushels. If your dryer isn’t running for that long, that can make a huge difference.”
- Manage dryability for different hybrids
“There is a lot of variation in the way different corn varieties dry,” according to Hartwig. “Even with the same hybrid, there can be drying differences in different years.”Woodruff says this has become a larger concern within the past five years. He recommends close monitoring of dryers when changing fields or varieties, in order to ensure that the dryer is operating according to your expectations.
- Check moisture controls
Pulling samples, checking the moisture control, and making sure the dryer is in the appropriate location will help you to make sure your dryer is running properly. “Moisture sensors are temperamental. It only takes one little stock of grain hanging up in the wrong place to throw their values off,” explains Hartwig. “You should pull samples two to three times a day.”
- Get an energy audit
“Sometimes you need someone who is willing to look at your entire operation to make sure that you are operating in the best way you can for your system,” Woodruff states. This can be accomplished through an energy audit, and your local NRCS office will likely be able to provide you with a list of professional energy audit providers in your area.