Penentuan Konstanta Pengeringan Dalam Sistem Pengeringan Lapis Tipis (Thin Layer Drying)

Abstract

Drying process was mainly influenced by the drying air condition, internal properties of solid and the drying system. The drying kinetic was controlled by a drying constant (K) with respect to thin layer drying model dependent on drying air flow-rate, moisture diffusivity, drying air conditions, the structure of solid micro porous, and solid moisture content and thickness. Coefficients of the drying constant were determined by fitting an empirical model on a set of experimental data of the thin layer drying. The empirical drying constants for potato was expressed as function of solid moisture content (X) and drying air temperature (T) investigated in the temperature and the moisture content ranges of 40 – 60 oC, and 0,001 – 0,45 kg water/kg dry solid, respectively as described as follows: K=0.00458 exp(-0.2474X) exp(-7401.9/RT). The Levenberg-Marquardt algorithm was implemented for the model fitting to determine the model coefficients. The drying kinetic including the drying constant can be used to predict the drying dynamic precisely in the thin layer drying system.