Abstract
A model of through-flow drying was developed in order to simulate the drying properties of beds packed with tobacco cut-filler placed in a flow of air or wet air mixed with superheated steam. This model was simplified as follows: (1) the fluid in the bed is regulated as plug flow; (2) a piece of the cut-filler is taken to have a plane-sheet shape; (3) the internal movement of water in the cut-filler is regarded as a rate-limiting step; and (4) the transfers of mass and heat are specified by a set of one-dimensional equations of convection and diffusion. In a wide range of 373 to 523 K, the calculated curves of moisture content and temperature of the tobacco were in agreement with experimental values. It was concluded that the model is valid and applicable to the estimation of drying properties of tobacco materials.
