Single layer drying behaviour of grenade peel in a forced convective solar dryer

Abstract

Solar drying experiments in thin layer of grenade peel were conducted in forced convection solar dryer consisting of a solar air collector, an auxiliary heater and a drying cabinet. Moreover, grenade peel is sufficiently dried in the ranges of 32 °C to 36 °C of ambient air temperature, 45 to 70 °C of drying air temperature, 32 to 53 % of relative humidity, 0.028 to 0.056 m3s-1 of drying air flow rate and 200 to 950 W/m2 of daily solar radiation. The experimental drying curves show only the falling drying rate period. The main factor in controlling the drying rate was the drying air temperature. The drying rate equation is determined empirically from the characteristic drying curve. Twelve mathematical models were tested to fit the experimental data. The Midilli-Kucuk model was found to satisfactorily describe the solar drying curves.