Abstract: In a drying oven having plural superposed endless belts on which material to be dried, such as fruit, moves in a circuitous path from top to bottom, excessive drying of the material on the lower belts is prevented, by directing hot air toward the upper belts but a mixture of hot air and relatively cool outside air toward the lower belts. Adjustable shutters for the inlet air, and for the division between the two portions of the hot air, are provided, there being separate fans for the two air streams.

Abstract: A drying oven comprises a plurality of superposed endless belt conveyers that feed each to the next lower conveyer. The upper two conveyers are separately fed from individual hoopers; and the third conveyer receives all the material from the upper two. In this way, fruits and vegetables of different sizes can be given different drying times, by running the two upper conveyers at different speeds. A plurality of superposed blowers with selectively adjustable louvers is provided, for regulating the flow of hot air to various of the superposed conveyers; and a fan can blow cooling air horizontally across certain of the conveyers.