Portable dryer cuts drying cost

Grain-drying can add plenty to the cost of producing and selling, prompting many farmers to examine their investment and operating expenses in conventional grain dryers.

“Farmers tell me it costs 30 to 50 cents per bushel to dry grain, factoring their investment plus wear on augers, PTOs, trucks and the dryer itself. Plus there’s fuel and labour,” states Mike Duns.

“We’re drying grain for less than a nickel per bushel,” says the owner of CanDri Industries in Saskatoon.

CanDri manufactures and markets two portable dryers. The Tornado has a single 390,000 BTU burner and the Cyclone has twin 390,000 BTU burners, designed for bins up to 30,000 bushels. While the burners are common off-the-shelf units, it’s the way Duns manages them that creates greater efficiency.

“Our system can reduce grain moisture content up to two percent per day. It mitigates grain damage by keeping grain in the bin, and requires fewer resources to dry your grain.”

“The smallest bin you can do with the single heater is 5,000 bushels. You don’t want to go smaller. That overheats the bottom of the bin because fans can’t move the BTUs fast enough. They don’t have enough air flow. You end up sweating the lower 500 or 1,000 bushels too quickly. Then the air gets so thick and next you get a little re-condensation so you don’t get any air through. If you don’t get any air through, you’re not getting moisture out of the bin.”

The Cyclone is often set up to dry two bins simultaneously, as shown. This dryer employs twin Flagro 400FBO 39,000 BTU, indirect-fire, diesel-fueled burners, the same units employed on the single-burner Tornado model. | Mike Duns photo

“There are key components in our system that I can’t divulge yet. But I can say that we’ve developed processes to mitigate the over-drying at the bottom of the bin and not drying at the top.”

Duns says many farmers use these types of supplemental heaters, but they run them 24-7. For example, they started at 17 percent, and run 24 hours a day. Duns says that block off their airflow. Water runs out the bottom of the bin and they end up with eight percent at the bottom. But it’s still 17 at the top.

“It’s not rocket science, but it’s close. The key is cycling the burner on and off. The system monitors bin temperature so the burner runs strategically. We want to heat the bottom grain up to 35 or 45 degrees. Then turn off the burner and push that layer of heat up through the grain with cold air from the fan.”

Duns says that on a typical 5,000 bushel bin, he would run the heat for four, five or maybe even six hours, depending on ambient temperature. The bottom two bin sensors see the temperature hitting the target and turn the burner off. The fan continues to run, pushing that layer of warm moisture out the top. He aims for air exiting the top to be about 18 C.

“Farmers have been using supplemental heat for decades, so that’s not new. It’s the process and management that’s new in this system. You don’t want to put too much BTU into a bin. That’s the worst thing you can do. Process is everything.”

Duns says his system can dry grain for less than a nickel per bushel, compared against 30 to 40 cents per bushel for conventional dryer systems. All diesel exhaust goes through the chimney stack, so no fumes enter the bin. The twin burner Cyclone lists for $22,900. The single burner Tornado lists for $7,900. | Mike Duns photo

He changes the amount of diesel entering the burn chamber by changing the nozzle. There’s a small 1.75 gallons per hour nozzle for warm weather. At the other extreme, he has the big 2.25 gph nozzle for coldest weather. Every burner also comes with two gph nozzle for in between. It takes about 10 minutes to change nozzles.

“Right now, there’s still some hands-on management. I work out a specific game plan for each farmer, so he turns it on and off at the correct times. We’re working on software right now to totally automate the system, with exhaust and bin sensor packages to enhance the efficiency. We can do that story in the spring.”

The burner for both models is a Flagro 400FBO 39,000 BTU indirect-fire diesel-fueled burner. The flame heats a plenum so it’s all clean air going into the bin. He says you can heat a house with these burners.

The single-burner Tornado sells for $7,900. The twin-burner Cyclone sells for $22,900.

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