105 Modelling Convective Drying of Soybean (Glycine Max L): Experiments and Numerical Simulation

The production of soybean (Glycine max L) requires that the product is collected healthy and in advance, to minimize losses caused by the attack in the field of insects, diseases and microorganisms. Therefore and due to high moisture content at harvest, drying is one of the operations of primary importance among the techniques involved in the conservation of desirable qualities of products of plant origin. The objective of this work is to obtain the drying curves of soya, in the range of drying air temperature between 45 and 90°C, for the initial moisture content between 0.13 and 0.32 and drying air velocity of 0, 0.5, 0.9, 1.5 and 2.5m/s to determine the influence of these parameters in the process. The experimental phase was performed using a prototype of which was a hair metal tube with 0.15m in diameter, insulated throughout its surface with glass wool and canvas. The air was heated by six electrical resistance with power of 600W, while the temperature was controlled with the aid of thermocouples connected to the drying equipment. Were also performed numerical simulations, where the mathematical model used was proposed by Khatchatourian [1], and this search has changed the equation that describes the flow of mass, it is entering the parameters of air velocity and initial moisture content, obtaining a good agreement between experimental and simulated data. Was observed that the drying air velocity presents significant influence on the process, there is an increased withdrawal of water during the first hours of drying. Note that the influence of air temperature on the rate of drying is higher at the beginning of the experiment, reducing the processing time. The higher the temperature and airflow, the greater the drying rate and lower the total time of exposure to heated air.