Deflectors as the performance booster component in designing a side-ventilated heat pump cabinet dryer for vegetables

Abstract

Unbalanced drying air and temperature distribution in a dryer is among the major cause of non-uniformity in moisture content of dried food. Thus, the distribution of air and temperature in corner-ended, corner-ended with deflector, curved-ended, and curved-ended with defectors were investigated. Velocities used were 2 m/s, 4 m/s, and 6 m/s while temperatures ranged from 40-60?C. The design with lowest deviations in simulated and actual drying parameters was fabricated to dry mushrooms. Results showed that adding deflectors improved drying air and temperature distribution. The corner-ended with deflector dryer configuration was superior to other designs, with 6 m/s and 60?C being optimal. A mass transfer simulation of the corner-ended with deflectors configuration had moisture evaporate from 1.00-0.11 in 2000 seconds. A comparison of moisture ratios in the two dryers gave R? = 0.9965, which was acceptable. Drying at 55-60?C gave the best Lentinan content and rehydration ratio for mushrooms.