CFD simulating of air moisture distribution inside the dryer and investigating its effect on the shrinkage rate of dried apples

Abstract

This study aims to simulate the effect of the drier humidity distribution on the temperature distribution and dried product shrinkage. The Lebanese yellow apple (Golden Delicious) was prepared in the form of slices with 3 and 5 mm thicknesses and dried at 60 °C in a hot air oven. Shrinkage models were determined by fitting the experimental data with Sigmaplot software. The simulation was done using these equations in COMSOL software. The simulation results showed that due to the accumulation of air humidity in one part of the oven, the temperature distribution inside the product was not distributed evenly in that part. This phenomenon caused the imbalance of moisture transfer from the product and this can increase the drying time as well as unbalanced shrinkage of the product. Finally, it was found that the air humidity distribution inside the oven had a significant effect on the drying process and shrinkage rate of samples.