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Abstract
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In this study, exergy analysis was applied for a rotating-tray dryer equipped with a cross-flow plate heat
exchanger during drying of apple slices. Three drying air temperatures and tray rotation speeds in the
range of 50–80 °C and 0–12 rpm, respectively, were employed. Two drying air velocities in the range of
1–2 m/s were adjusted for each drying temperature and rotation speed with and without application of
the heat exchanger. The experiments were conducted to assess the effects of the experimental variables
on the exergetic performance parameters of the dryer. Also, the effect of drying conditions on the quality
of dried apple sliceswas assessed by determining rehydration ratio, apparent density, shrinkage, and surface
color. In general, the exergetic performance parameters of the dryer depended profoundly on the drying
air temperature and velocity. Interestingly, the exergetic efficiency of drying process was significantly
improved from a minimum value of 23.0% to a maximum value of 96.1% by using the heat exchanger.
Furthermore, the incorporation of heat exchanger did not negatively affect the quality of dried product.
Therefore, the strategy presented herein could be a promising approach for waste energy recovery in
drying without any unfavorable change in the quality of dried product
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