Experimental performance of mushroom fluidized-bed drying: Effect of osmotic pretreatment and air recirculation

The present work evaluates the effect of osmotic pretreatment (OP) and air recirculation (AR) on energy and exergy analyses of fluidized bed drying of sliced mushroom at different drying conditions. The drying was carried out at drying temperatures of 30, 40 and 50 °C, air superficial velocities of 3, 5, and 7 m/s for osmotic pre-treatment and untreated (control) samples under with/without air recirculation. Results showed that both air recirculation and osmotic pretreatment significantly effect on energy and exergy parameters. The energy consumption increased with increasing air velocity and drying temperature while it decreased with using osmotic pretreatment and air recirculation techniques. The energy utilization ratios vary between 0.10 and 0.269 for control/NAR and 0.890 to 0.964 for OP/100% AR, while exergy efficiency vary from 10.40 to 30.57% and 0.81-3.94% for OP/100% AR and control/NAR, respectively. Exergy loss significantly decreased with recycling the exhaust air.