A mathematical analysis of pneumatic drying of grains—II. Falling rate drying

Abstract Analytical solutions, based on the diffusion equation, are presented in describing the pneumatic drying of grains during the falling rate period. Humidity variation of the air along the length of the duct is taken into consideration as well as the internal and external resistance of the mass transfer in the grain. For a Biot number greater than 100, the internal diffusion resistance is the dominant factor for the drying process.