Vibration effects on convective air-drying of bulk pistachios

Abstract: The drying performance of bulk pistachios in a laboratory scale vibrated bed dryer was investigated under various operating conditions: inlet air temperature (50±2°C), air velocity (at 1.0 m/sec), frequency (0–60 Hz), amplitude (0.6 mm) and bed height (100 cm). The drying results showed that rising in drying efficiencies from 51.10 % in 0 Hz to 76.90 % in 50 Hz. Higher vibration intensity could not induce stronger efficiencies. The Logarithmic models provided the best fit of these drying results and further implied that the moisture transfer of pistachios was mainly controlled by internal diffusion. In comparison with the case of a conventional dryer, the air-vibro bed dryer showed improvement of drying characteristics, so the drying kinetics was largely dependent on the frequency of vibration