Drying of orange juice waste in a mechanically stirred spouted bed

Orange juice waste is an agro-industrial bio-waste produced on large-scale, which may be transformed into a source of raw material through drying. Drying of orange juice solid residue was carried out in a mechanically stirred spouted bed equipped with four sets of equally spaced blades placed around the stirrer shaft. The experiments were conducted at temperatures between 40 and 80°C with air flow rates of 1–5 times the minimum spouting velocity. Mechanical agitation has proven to increase the movement of solids, especially in areas close to the internal wall. The pseudo-fluidized regime allowed improving both bed uniformity and process stability. The drying energy demand was 12.6–23.4 % of that of the conventional bed. During much of the drying time of the solid orange juice residue, the air was saturated at the exit due to the low air flow rates used in the process.