Analysis of air velocity distribution in a laboratory batch-type tray air dryer by computational fluid dynamics
Vouros, Alexandros
Margaris, Dionissios
Bardakas, Achilleas
Tzempelikos, Dimitrios
Filios, Andronikos
Βούρος, Αλέξανδρος
Φιλιός, Ανδρόνικος
Μάργαρης, Διονύσιος
Τζεμπελίκος, Δημήτριος
Μπαρδάκας, Αχιλλέας
Batch dryers are some of the most widespread
equipment used for fruit dehydration. Nevertheless, the optimization
of the air distribution inside the drying chamber of a batch dryer
remains a very important point, due to its strong effect on drying
efficiency as well as the uniformity of the moisture content of the
drying products. A new scale laboratory batch-type tray air (BTA)
dryer was designed, constructed and evaluated for the drying of
several horticultural and agricultural products. The airflow field
inside the dryer was studied through a commercial computational
fluid dynamics (CFD) package. A three-dimensional model for a
laboratory BTA dryer was created and the steady-state
incompressible, Reynolds-Averaged Navier-Stokes equations that
formulate the flow problem were solved, incorporating standard and
RNG k-ε turbulence models. In the simulation, the tray, used inside
the BTA drying chamber, was modeled as a thin porous media of
finite thickness. The simulations for testing the chamber were
conducted at an average velocity of 2.9 m/s at ambient temperature.
The CFD models were evaluated by comparing the airflow patterns
and velocity distributions to the measured data. Numerical
simulations and measurements showed that the new scale laboratory
BTA dryer is able to produce a sufficiently uniform air distribution
throughout the testing chamber of the dryer.
University of Patras
