An experimental study on convective drying of quince

Abstract

A laboratory convective drying unit (LCDU) has been designed, constructed and equipped with an integrated measurement and control instrumentation, in order to evaluate the essential drying characteristics of various horticultural and agricultural products. The current paper presents experimental results from tests with quince slices. Drying kinetics was investigated as a function of drying conditions. Experiments were conducted at air flow temperatures of 40, 50 and 60oC and average velocities of 1, 2 and 3 m/s. Temperature changes of the drying quince samples, the relative humidity and the temperature of the drying air were measured during the drying processes and finally the moisture ratio (MR) was calculated. The experimental MR data were fitted with three mathematical models available in the literature and a good agreement was observed. In the ranges measured, Fick’s 2nd law of diffusion was used to fit the experimental data for the determination of the effective moisture diffusivity. The activation energy was determined, assuming an Arrhenius type temperature relationship with moisture diffusivity.