ABSTRACT
The utilization of solar energy for the drying of agricultural produce is a sustainable and cost-effective solution that addresses the increasing demand for energy-efficient food processing methods. In this study, an IoT-integrated indirect solar dryer is developed for dehydration of agricultural produce. Experimental tests were conducted on potato slices with thicknesses of 3 mm, 5 mm, and 7 mm. Each test was conducted from 9 am to 6 pm, under average ambient temperature of 32.25 ± 0.20 °C and average solar radiation of 565 ± 10 W/m2. For the given drying period, thinner slices experienced higher moisture loss. For a 7 mm slice thickness, the moisture content of potato reduced to 13.6 % with an average drying rate of 0.54 kg/hr and drying efficiency of 31.71 %. On the other hand, thinner slices (3 mm) showed higher moisture loss up to 5.6 % moisture content with enhanced average drying rate of 0.67 kg/hr and average efficiency of 39.06 %. Furthermore, the mean specific energy consumption decreased by 11.5 % and 18.5 % respectively for 5 mm and 3 mm thick slice, compared to 7 mm. The drying curves of all tests were tested with different thin layer drying models. For all tests, the Modified Page model accurately predicted the moisture ratio of product with higher correlation coefficient (R2 = 0.9970 to 0.9974), lower root mean squared error (RMSE = 0.0156 to 0.0167) and lower chi-square value (χ2 = 7.97 × 10−03 to 1.40 × 10−02).
2024- Solar Energy