Thesis Type:

Abstract:

In this research, an indirect solar dryer (SSI) was designed and tested for drying tomato in thin layer. It operates without additional energy in the passive and active convective modes. Before realizing the solar drying tests in the SSI, the cover and the absorber of the flat-plate solar collector (CSPA) were optimized. The convective and solar drying of watermelon and tomato occur during the falling drying phase and the Verma and Midilli-Kucuk model are those that perfectly describe the drying of both two fruits, respectively. The follow-up of the shrinkage during the drying of both fruits was realized by X-ray microtomography. In addition to the experimental study, a computer program (Mod_CSPA) for CSPA and a computer program (Mod_CHS) for the drying chamber (CHS) were developed. Mod_CSPA was experimentally validated and it was shown that the optimal inclination of CSPA is variable during the year. The numerical simulation of the mass and heat transfer during the solar drying in thick layer of tomato slices showed that the energy supplied by the drying air is of use to the water evaporation and the temperature rise of the dried fruit.

Keywords: Indirect solar dryer (SSI) - Flat-plate solar collector (CSPA) - Shrinkage - X-ray microtomography - Drying kinetics - Simulation.

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