Experimental Study on Eggplant Drying by an Indirect Solar Dryer and Open Sun Drying

In this article, an indirect forced convection solar dryer is used to study the kinetic drying of eggplant. The effective moisture diffusivity calculated by slop method follows the solar intensity with themaximum value of 1.68 E-09 at 15 PM. Performance of solar dryer is determined by defining the efficiency ofcollector and an effectiveness factor as the ratio of the drying rate in the indirect solar dryer to the drying rate in the open sun. The collector efficiency and the effectiveness factor vary with the drying time inversely Results show that the drying rate in the solar dryer is 3.5 g H O. g ds-1 Hr-1 and is 2 g H2O. g ds-1Hr-1for the open sun drying method in the beginning of the process. Several well-known mathematical models are applied in order to select the best model to present the eggplant drying behavior. Midilli and Kucuck model refers to drying process of product with correlation coefficients (R2) which are 0.9998 for solar dryer and 0.9996 for open sun