Home-Built Wrap-Around Grain Dryer Heat Exhanger

Home-Built Wrap-Around Grain Dryer Heat Exhanger GRAIN DRYERS Grain Dryers (29E) 18-1-34 My home-built 'wrap-around' grain dryer heat exchanger was featured in FARM SHOW 7 years ago (Vol. 11, No. 4). Back then I made the heat exchanger for my Farm Fans AB12 grain dryer. Since then I've redesigned it for my Fan Fans CF/AB 190 dryer and it's currently a semi-finalist in Farm Bureau's national Inventions Contest. The heat ex-changer is designed to reduce drying costs by saving energy. Last fall my per bushel drying cost was 12.2 cents (propane only) compared to 20 to 25 cents per bushel for other farmers in my county. Average moisture content of corn in our county was 33%. The heat exchanger consists of 144 aluminum pipes running horizontally the length of the dryer, 72 on each side. The 4-in. dia. pipes are shrouded by a sheet metal housing and lead to a pair of round ducts that are connected to the burner fan in front of the dryer. Fresh air is sucked in through the pipes, which protrude from the end opposite the dryer's fan, while hot, moist exhaust air from the dryer circulates around the outside of the fresh air pipes. Heat is transferred to the ambient air flowing through the pipes as it makes its way to the burner fan. The burner fan heats this preheated air up to 200 degrees, then forces it back through the grain around the outside of the tubes and out into the atmosphere through a 9-in. wide opening that runs along the full length of the dryer at the top. A sheet metal housing encloses the entire fan and burner assembly. The key benefit is that it uses the warm, moist air that normally escapes into the atmosphere to preheat fresh air inside the pipes before the air enters the burner fan. Most commercial heat exchangers recycle air that comes out of the dryer, which is more moist and therefore reduces grain drying capacity. My heat exchanger would work on new or existing grain dryers. I plan to manufacture it. (Ken Studer, 7633 Auburn Center Rd., Tiro, Ohio 44887 ph 419 347-6718)

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