Introducing a Novel Hybrid Solar Dryer for Tomatoes: Design and Performance Evaluation

The main objective of this work is to design, construct, and test a forced convection solar dryer system and compare the obtained experimental data with those of an existing model. Our system, which consists of two 370W-PV panels, a 12V DC-fan, a 1.3 m2 thermal collector, two thermometers, and a single drying chamber with dimensions of (0.5 x 0.5 x 0.8) m3, is powered by the photovoltaic panels. These panels drive the DC fan, which circulates ambient air that is then heated in a solar thermal collector. The heated air is then delivered to the drying chamber, where it effectively dries the moist products. Tomato slices were used as a testing sample since tomatoes have a significant moisture content; this makes it easy to notice and record the changes in sample shape and moisture content over a short period. The study was conducted using the evaporation rate criterion. It was found that high moisture content was removed from tomato slices with an average evaporation rate of 3.84 g/hr for 565 g of tomato slices over six days, as the system achieved a maximum drying chamber temperature of 68 ° C and a maximum temperature difference of 47 ° C. These findings were in good agreement with those obtained by the Lewis model.