Solar pre-heat chamber for grain dryers

Claim 1

In a crop-drying system including a grain-confining bin having generally inperforate top and side walls, venting means at the top of said bin, and grain-supporting perforate base means adjacent the base of said bin, said imperforate side and top walls, and said grain-supporting perforate base defining a graindrying chamber, impeller means for forcibly delivering drying air to a zone beneath said grain-supporting perforate base for passage through said drying chamber and including solar energy extracting means for heating said drying air prior to passage through said drying bin, said solar energy extracting means comprising: a. an elongated solar heating chamber having one end in direct communication with the input end of said impeller means, and with the opposed remote end in communication with atmosphere, and comprising frame means with generally water impermeable bottom, side and top walls, said walls being wrapped about said frame means and defining said solar heating chamber, said solar heating chamber having a length-to-width dimension ratio of at least about 10; b. said bottom wall being an opaque flexible cohesive film, highly absorbant to solar radiation, with said side and top walls being transparent flexible cohesive films, highly transmissive to solar radiation; and c. the input end of said impeller means receiving drying air from said elongated solar heating chamber and from the ambient.