Energy and exergy analyses of continues infrared-hot air current dryer with air recycling

Document Type : Research Article


1 BA Department of Biosystems Engineering; of Agriculture; University of Kurdistan, Sanandaj, Kurdistan, Iran

2 Department of Biosystems Engineering; Faculty of Agriculture; University of Kurdistan, Sanandaj, Kurdistan, Iran


Energy and exergy analyses were conducted of the continuous combined infrared-hot dryer with current bed structure. The experiments were carried out at three levels of air temperature (40, 50 and 60 °C), three levels of air velocity (0.5, 1.0, and 1.5 m/s) and three levels of infrared power (500, 600 and 700 W) under without and 100% air recirculation for savory. Using 100% air recirculation indicated that specific energy consumption could be saved from 29.10 to 50.34% as compared without air recirculation. The use of high levels of infrared power and air temperature and low levels of air velocity with air recirculation led to increase energy efficiency (p<0.05). Maximum energy efficiency for without and 100% air recirculation modes was obtained 20.90% and 30.21%, respectively. Specific energy loss is strongly influenced by air velocity and air recirculation mode (p<0.05). Energy loss varied between 8.54 and 37.24 MJ/kg-water, and 5.21 and 20.04 MJ/kg -water for without and 100% air recirculation modes, respectively. The air temperature and velocity had the greatest effect on exergy efficiency, maximum value of it was obtained 10.21% for conditions of 60ºC, 0.5 m/s and 700 W with 100% air recirculation. The exergetic improvement potential vaired between 2.73 – 5.12 Mj/kg water and 2.35 – 4.02 MJ/kg water for whitout and 100% recirculation modes, respectively.


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