Design and performance evaluation of convective drier and prediction of drying characteristics of potato under varying conditions

An experimental setup is designed and developed for characterization of convective drying of food products under various operating conditions. The experiments are performed with cylindrical shaped potato samples at varying air velocity and temperature. From the experimental data, variation of transient moisture content, drying rate, effective moisture diffusivity and activation energy are determined. Air flow velocity and temperature have significant effect on the drying time of the potato sample. Around 30% drying time is reduced when air velocity is increased from 2 to 6 m/s and around 36% drying time is saved when air temperature is raised from 40 to 60 degrees C. The performance of the test dryer is evaluated based on its energy consumption and specific energy consumption (SEC). It is observed that the energy consumption and SEC increases with air velocity and temperature. Further, the effective moisture diffusivity is increased with an increase in air velocity and temperature and its value lies in the range of 3.78 x 10(-10) - 1.45 x 10(-9) m(2)/s. Correlations for energy consumption and effective moisture diffusivity are proposed. The statistical model for energy consumption and effective moisture diffusivity are also developed by correlating air velocity and temperature. The adequacy of the model and analysis of experimental data are done using analysis of variance.