الفهرس 
Introduction and Literature ReviewOnly 14 pages are availabe for public view
 |  | from | 209 |  |  |
| | | from | 209 | | |
Abstract
Drying process is considered one of the most complex processes encountered in engineering, A mathematical model developed for simulating a convective heat mass transfer during drying process. The model incorporates mass and heat transfer relationships within the organic material. A Fortran program is constructed to solve the two-dimensional coupled heat and mass transfer equations outside and inside the organic material during the drying process. The validated numerical model is used to investigate the effect of external conditions such as the variation in Reynolds number, the bulk air temperature, relative humidity, porosity of sample, Fourier number and height of sample. The experimental test rig is designed and constructed to study the heat and mass transfer during drying of organic material, grapes. The effect of external conditions are studied where the air velocity varied between 0.30 m/s to 1.57 m/s, the bulk air temperatures varied between 30 to 60 °C resulting in variation of relative humidity between 10 – 30 %, In addition, to evaluate the effect of the sample size on the drying rate, four different thicknesses and six different porosities are used. Also, a study to the energy consumption during drying process is carried out, the results shows an energy saving of 46 % due to increase in the air velocity, while the saving is 36 % due to increasing the inlet temperature of the drying medium. Also the maximum shrinkage of the sample is about 12.1%.