Potato processing: phenomenology and influence of vibration on bed movement

The configuration of the vibro-spouted bed dryer resembles that of a conventional spouted bed, but the circulation of the particles is controlled by a vertical imposed. As consequence, all the bed flows in a dense phase regime and the air velocity inside the bed is defined according to drying requirements alone. A dryer used in this study consists of a cylindrical chamber with a conical bottom (diameter 145 mm, height 390 mm) equipped with a perforated mobile base, which vibrated at a defined amplitude and frequency. Potato cubes consisting of 5 and 10 mm edges were dried and the behavior of the particles during drying was phenomenologically studied. Shrinkage of potato cubes during drying adequately fit the uniform drying model up to a moisture content of 0.9 kg water/kg dry potato. During the drying of cubes with 5 and 10 mm edges, cracks appear on the faces of the cubes. Fornell's modified model, denoted a good fit to the experimental points, and allowed the generation of characteristic drying curves both at the vary the temperature as the speed of the drying air, useful for computational modeling.