A Model to Simulate Chopped Alfalfa Drying in a Fixed Deep Bed

A model to simulate the drying process of chopped alfalfa is presented. The drying profile of a fixed bed dryer has been simulated through a system of five partial and ordinary differential equations, which describe the changes of the physical properties of the product, as well as the thermodynamic data of the drying air. The equations were solved using the thin-layer drying theory. In order to check the accuracy of the model, the drying rate curves at various depths of four deep-bed batches were calculated and the results were compared with experimental measurements, under the same conditions. The proposed model predicts accurately the drying rate of chopped alfalfa under a wide range of drying air conditions, and thus, the drying profile of the batch can be determined at any time.