App allows grain dryer control from combine cab

Yorkshire grower Graham Potter enjoyed a less stressful harvest this year thanks to an iPad app that gave him control of the farm’s grain drying plant from the combine cab.

It not only enabled him to keep an eye on the process, which resulted in more efficient drying, but also cut a tractor and trailer out of the harvest operation.

“When you’re on the combine all day, it’s a bit stressful having to keep asking the tractor drivers if everything’s OK at the store,” he says. “With the iPad app, that’s all gone – I can see exactly what’s happening with the handling equipment and the dryer, and make adjustments as necessary. It’s brilliant.”

The new high-tech approach to grain intake and drying management came about with the help of two friends.

First, Patrick Smart of Smart Tech Control Systems suggested automating the newly upgraded grain plant at The Grange, where W Potter & Sons grow wheat and oilseed rape, plus fodder beet as a break crop, on 200ha near Topcliffe, North Yorkshire.

“When a big floor storage unit became available at The Grange, we moved our Svegma continuous flow dryer from another unit, where everything was stored in bins,” explains Mr Potter. “The dryer was extended and equipped with a new burner and furnace to increase capacity to match our combine.

“But it was on manual control and since I didn’t want someone standing watching over it full time, I had our two trailer drivers check the plant and take a moisture sample every time they tipped a load.”

As a former feed mill technician, Mr Smart had the means to design a modern control system using robust PLC (programmable logic control) components connected to sensors on key elements of the plant, including three fill-level sensors on the dryer.

“The more Graham realised what was possible, the more he wanted,” says Mr Smart, who linked the new digital system to the old switch box and designed an operating interface displayed on computers in the farm office and in the grain store.


With built-in logic and routing intelligence, the plant now starts and shuts off elevators and conveyors in the correct sequence, will respond to blockages and other malfunctions, and automatically feeds the dryer as long as there is sufficient grain in the pit. It also records fuel and electricity usage for accurate contract drying costings.

Furthermore, the drying process can now be operated automatically, responding to continuous moisture readings from a Hydronix digital microwave sensor positioned after the dryer.

Here again, a degree of ‘intelligence’ is built in: “The control system will make very small adjustments to dryer speed; we’re talking tenths of seconds,” says Mr Smart. “But if there’s a significant jump in moisture level, it will respond accordingly with a larger speed change.”

Mr Potter points out that previously the system would have been adjusted manually two seconds at a time maybe every half hour, so the new controller regulates drying more effectively and the moisture meter eliminates the time trailer drivers spent taking moisture samples.

“Next I thought about having a number of digital cameras on the plant so I could keep an eye on the elevators and conveyors on my smartphone,” Mr Potter adds. “But Patrick suggested an iPad app to put the control and monitoring system into the combine cab.”

Data transmitted from the controller to a server computer is collected by the app written by his friend David White. It faithfully reproduces the grain store computer display on the iPad screen.

“For safety, I can’t start up the plant remotely,” Mr Potter emphasises. “But once it’s been fired up after a couple of trailer loads have been tipped, I can control the drying process manually through the touch screen, and then switch to automatic once it’s settled down.”

The best thing, he says, is the peace of mind that comes with seeing everything working as it should in the store while continuing to cut corn. But there is also significant value in being able to accurately regulate the drying process and switch to ambient drying when appropriate to save fuel.

“Faster trailer turnarounds are also significant; that much time was saved managing the dryer from the combine that we needed only one tractor and trailer instead of two,” Mr Potter points out. “Harvest is always going to be a bit stressful but this system not only brought tangible benefits, it also reduced my stress levels by putting all the dryer information and control I needed at my fingertips.”

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