Experimental and numerical investigation of simultaneous heat and mass transfer in industrial materials

The drying process is widely used to prevent microbial deterioration by evaporating the amount of liquid from the food product. Modeling and optimization of the drying process is very important to reduce energy consumption and improve food quality. Therefore, different approaches have been used in the literature to investigate drying characteristics. Among these approaches, Fourier and Fick's law are widely used for simultaneous heat and mass transfer. However, since the porous media approach (Darcy Flow) has a complex mechanism, it has been found that it is not preferred much in the literature studies. In this study, drying characteristics of the products were investigated for both methods. The effect of different parameters (velocity, temperature, thickness) on product moisture, shrinkage coefficient, exergy efficiency and exergetic development potential values in the convective study was examined with the help of Anova analysis used for Taguchi experimental design. Optimum drying conditions were observed at the highest air velocity (1 m/s), the highest temperature (60 °C) and the lowest product thickness (0.5 cm). The effect of different parameters (velocity, radiation power, radiation lamp distance) was investigated for infrared radiation dryer. Optimum drying conditions were obtained as a velocity of 0.3 m/s, 350 W radiation power and 20 cm distance to radiation lamp. In exergy efficiency, air temperature (88.54%) was the most effective parameter in convective drying, while radiation lamp power (39.61%) was the most important parameter in radiative drying. Studies were carried out using both experimental and numerical methods. In the drying problem, nonlinear partial differential equations for food product are solved with time. The shrinkage effect of the drying process was examined in Comsol Multiphysics program by using "Deformed-Moving Mesh" method. The data obtained with the experimental and numerical solution were compared and the results were found to be consistent with each other. High moisture content in the product causes microorganisms to form. For this reason, in cases where the moisture distribution in the product cannot be determined experimentally, a numerical solution can be made and thus it will be possible to prevent this negativity in advance.