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DRI-Stack aims to alleviate harvest grain handling headaches

Iowa State alumni develop DRI-Stack to speed grain drying, reduce energy use, and improve grain quality.

Each fall any number of variables can slow down harvest. Whether long lines at the elevator or drying speed, it pays to remove bottlenecks for improved efficiency.

“For years, we used a continuous flow dryer that was PTO-driven. It had a lot of moving parts and consumed a great deal of our time in the fall,” says Keith Glienke, who farms in northwest Iowa with son Jason. “I wanted to upgrade to a better system, but many options were cost-prohibitive.”

In search of an affordable way to improve grain drying, Glienke came across DRI-Stack by Haber Technologies based in Ames, Iowa. Developed by Iowa State University alumni Eric Harweger and Dillon Hurd, the system consists of a series of air tube stacks containing valves that direct airflow to specific locations within a grain bin more efficiently than traditional plenum-based grain drying and aeration systems. DRI-Stack can dry high-moisture corn (up to 25%) in less time using less energy, while reducing damage. 

“Compared with natural air drying, the DRI-Stack can dry corn up to five times faster, and it’s 50% more energy-efficient. We accomplish that by breaking the bin up into 7-foot sections,” says Ethan Marti, head of sales, Haber Technologies. “Each of the pneumatically powered valves can release and receive air, which is taken from the plenum and released at higher levels in the bin. By drying in layers, corn dries more quickly, yet it maintains its quality.”

Valves and sensors are linked to a computer on the outside of the bin that syncs with a cell phone. The computer also controls the fans and the low-heat burner. Once grain is at the desired moisture, the fully automated system continues to monitor and aerate grain, and it precisely directs air to hot spots when an abnormality appears in the bin. When it’s time to clean out the bin, the stacks retract so a sweep auger can run underneath.

Investing in DRI-Stack 

In 2020, Glienke erected a 42-foot bin that holds 40,000 bushels, and he equipped it with the DRI-Stack. The system’s simplicity is what initially caught his attention. “All I had to do was set up the auger and load the bin. I didn’t have to move corn to the dryer and then into another bin. I simply filled the bin and turned the system on,” he says.

For its first run, the DRI-Stack was tasked with drying late-maturing corn at around 22% moisture. Glienke admits he was anxious about how the system would perform.

“Typically, a traditional natural air-drying system takes a lot of fan capacity because you’re pushing the moisture all the way through the grain, to the top,” he says. “Although my bin has nine rings, the company said it only needed one 20-hp. fan.”

Within 10 days, moisture was at 15.5%. “With three-phase electric power, it cost me 4¢ a bushel to get it to that level,” Glienke says. “Not only is it inexpensive compared with a conventional drying system, but the DRI-Stack also allowed me to harvest my later-maturing corn first and let early-maturing varieties dry in the field. If it was a wet fall, I could probably turn the same bin over three times in a season if I needed to.”

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