Agriculture & Food, Volume 8, 2020

Abstract: The study aims at finding the rate of drying and other particulars of the convective dehydration process of apple rings in the domestic type apparatus. The rationale behind the design and key parameters of the vortex dehydrator are presented. Modelling of the drying process in the vortex dehydrator that provides a nearly uniform rate of convective drying of apple rings using airflow of ambient temperature and low humidity has been carried out and tested. The process also implies the convective drying of apple rings by air at the ambient temperature may be diversified by including a weak heating from the below at the final period of drying. The key modeling input parameters, such as the activation energy and mass transfer coefficients have been determined in customized experiments. Activation energy has been estimated for the single ring under natural convection condition; in the following this function has been used for calculation of drying rate of apple rings in the vortex unit under forced convection. The COMSOL Multiphysics 5.5 software package has been used for simulation of the drying curve, the temperature and water vapour concentration inside the apparatus during the dehydration process.