Nonequilibrium Thermal Dynamic Modeling of Porous Medium Vacuum Drying Process

Nonequilibrium Thermal Dynamic Modeling of Porous Medium Vacuum Drying Process

Porous medium vacuum drying is a complicated heat and mass transfer process. Based on the theory of heat and mass transfer, a coupled model for the porous medium vacuum drying process is constructed. The model is implemented and solved using COMSOL software. The water evaporation rate is determined using a nonequilibrium method with the rate constant parameter Kr. Kr values of 1, 10, 1000, and ...

Modeling of Vacuum Drying of Licorice (Glycyrrhizia glabra) Roots

Background and Objectives: Desiccation is a necessary procedure to eliminate moisture from foodstuffs in industries, especially pharmaceutical, food and tobacco industries. In the present study, a mathematical modeling was assessed for vacuum drying of the licorice roots. Materials and Methods: Fresh licorice roots were dried at 50 mbar. Temperatures included 22to 150°C and diameters of roots ...

Modeling Plain Vacuum Drying by Considering a Dynamic Capillary Pressure

A coupled drying model for wood is proposed by introducing a dynamic capillary pressure. The pressures of non-wetting phase, the wetting phase, and the capillary pressure at equilibrium has been considered as non-static; this approach includes a two-scale model. According to numerical results, liquid, water vapor and air dynamics in the chamber have strong interactions with re-homogenization in...

Nonequilibrium Dynamic Modeling of Hydrogen Sulfide Absorption Using Diglycolamine Solution

Vacuum Drying Characteristics of Some Vegetables

In this research the drying of four kinds of vegetables was investigated in a vacuum dryer. The effect of temperature on drying rate of samples at various temperatures (30, 35 and 45 °C) was studied. Six thin-layer drying models were fitted to drying data and suitable model was selected from them. Then effective moisture diffusivity and ...