A method for the calculation of the heat transfer coefficient in potato drying
A method for the determination of the heat transfer coefficient was proposed for the first falling drying period of potato cubes. During this period, heat and mass transfer were considered as coupled phenomena. Temperature calculation inside the sample was performed using the macroscopic heat transfer balance. The heat transfer coefficient was computed by means of parametric identification, using the Gauss–Newton method. The figure obtained for the heat transfer coefficient shows good agreement with other sources.
Drying of shrinking cylinder-shaped bodies
Abstract A mathematical model has been developed for the prediction of sample temperature, average moisture and moisture distribution in a cylinder-shaped solid during the drying process. The effect of shrinkage was taken into account. The macroscopic heat balance and the microscopic mass balance combined with Fick's law were simultaneously solved using the Runge-Kutta-Merson method and a numerical finite difference method. The effective diffusion coefficient was expressed as a function of sample temperature and local moisture content. Using an experimental drying curve determined at 90 °C, the diffusional equation was identified for broccoli stems, and was used to predict the average and l…