"Vacuum Aeration" Fan Pulls Air Down Through Bins

"Vacuum Aeration" Fan Pulls Air Down Through Bins GRAIN HANDLING Miscellaneous 30-1-29 "I've been using this idea for more than 20 years in my own bins," says farmer-inventor Norval Semchenko, Max, N. Dak., about his vacuum aeration fan system for grain bins that pulls air down through stored grain rather than pushing the air up. Here, according to Semchenko, is the problem with conventional "pressure" aeration. "Moisture often condenses on the roof and drips back onto the grain. You can add larger vents but that costs money and lets in snow and rain. Also, every grain bin leaks air somewhere, but it's difficult to seal the bin when you're pressurizing it from the inside. When you're creating a vacuum by pulling air down through a bin, it's much easier to seal up any leaks." Another advantage of vacuum aeration is that it pulls down drier air from up above the bin. "Often air at ground level has higher moisture content, whether from morning dew or from the wet ground," he notes. One thing Semchenko has always liked about his vacuum aeration system is that he can "feel" the air coming out of the bin when he stands by the aeration fan. "I've gotten so I can tell when the grain is dry just by the moisture content of the exhaust, but you can also buy an inexpensive humidity indicator and use an equilibrium moisture chart to figure out the moisture content of the grain without the need for a probe," he says. Semchenko's specially-designed 18-in. dia. fan is powered by a custom-built Baldor 4-hp electric motor. The fan housing creates a venturi action by narrowing down from 18 in. to 15 in. as air is drawn from the bin, smoothing out the air flow to the fan blade tips. "If you just took a regular fan and reserved it, you'd get a lot of turbulence at the fan, reducing efficiency. Our design eliminates that problem." The vacuum aeration fan simply mounts in place of existing fans with no need for modification of the bin. Adaptor rings are available, if needed, to match up to larger size openings. "It's ideal for 18-ft. dia. bins up to 5,000 bu. but I think it will work on larger bins. We're still testing with larger bins," says Semchenko. He says there used to be a manufacturer in Kansas who made a vacuum aeration fan using a 1 1/2 hp motor and many farmers in his area owned them. But that company went out of business in the early 1990's and, as far as Semchenko knows, there's nothing else like them on the market today. Semchenko is putting his aeration fan on the market for the first time this year for $700. The adapter ring, if needed, sells for $50. Contact: FARM SHOW Followup, AirMasterMax, 3216 25th St NW, Max, N. Dak. 58759 (ph 701 679-2111; www.air mastermax.com).

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