Development of an Indirect Forced Flow Greenhouse Solar Dryer for Barberry Drying

Barberry (Berberis vulgaris L.) is an important horticultural plant mostly cultivated in Iran. Since fresh barberry fruit has a high moisture content its shelf life is very short. Therefore, product drying after harvesting is necessary. On the other hand, because the moisture of barberry fruit is capsulated in the skin, its drying is very energy-consuming process. So, the present study proposed an indirect forced flow solar greenhouse dryer, to evaluate the dryer, a prototype was constructed, and its performance was experimentally investigated. In this way, the tests were carried out at different drying temperatures (30, 40, and 55oC) and drying air velocities (0.5, 1, and 1.5m/s). The results indicated that raising the temperature from 30 to 55oC decreased drying time by 8%. Similarly, drying time decreased by around 24% when the air velocity increased from 0.5 to 1.5m/s. The obtained specific energy consumption (SEC) values were between 0.11 and 1.1 kWh/kg. The lowest SEC was achieved at the lowest temperature with the highest velocity. Finally, it was found that the higher drying rates, the puffier products.