The experimental investigation and mathematical modeling of drying of apple in the carbon fiber cabinet dryer and the energetic/exergetic evaluation of the process

In this thesis, the drying process of the apple samples having different shapes (slab slice, ring slice and cube) in the carbon fiber cabinet drier (CFCD) at 60° C was investigated, experimentally and theoretically. The shape difference of the samples was found to be effective on drying time (p<0.05). After drying of apple samples having different shapes, the changes on some quality characteristics (total phenolic content, antioxidant activity, ascorbic acid content, color properties, density, and textural properties) were significantly different (p<0.05).In general, it was determined that exergy efficiency was range of %9.53-%10.65 and development potential was range of 117.80-127.88 kJ of drying process. It was determined that the best model describing the drying behavior was 'Diffusion Approach' for slab and ring slices while it was 'Wang and Singh' model for cube slices. The drying process was investigated numerically (finite difference and finite element methods) for the cases of only mass transfer or simultaneous heat and mass transfer, where the shrinkage was included or neglected. The physical changes (size, area, volume) of apple samples having different shapes during drying were determined by image processing method. The dimensional changes determined from this method were integrated into Deff calculations, and numerical models.For both numerical methods applied, models having good agreements with experimental data have been developed.