Simulation of a batch dryer by the finite difference method

Turan, Umut
The objectives of this study are to investigate the dynamic behavior of an apple slab subjected to drying at constant external conditions and under changing in the drying temperatures and to determine the effects of temperature and time combinations at different steps during drying on the process dynamics parameters, time constant and process gain of the system. For this purpose, a semi-batch dryer system was simulated by using integral method of analysis. Initially, the dynamic behavior of the drying temperature was investigated by using first order system dynamic model. Process dynamic parameters, time constant and process gain of the system, for change in drying temperature were determined. Secondly, investigation of the drying kinetics of the apple slab was carried out under constant external conditions in a semi-batch dryer. A mathematical model for diffusion mechanism assumed in one dimensional transient analysis of moisture distribution was solved by using explicit finite difference method of analysis. Thirdly, investigation of the drying kinetics of the apple slab was carried out under change in drying temperature at different time steps during drying. Inverse response system model was used for the representation of the dynamic behavior of drying. Process dynamic parameters, time constant and process gain of the system were determined. Model predicted results for apple slab drying under constant external condition and under step change in the drying temperature were compared with the experimental data.


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The aim of this study was to investigate drying characteristics (temperature gradient, rate of drying and temperature change, drying time, diffusivity values, shrinkage) of isotropic and anisotropic foods by observing the changes in temperatures at four different locations and moisture contents and to build an appropriate model for simulation of temperature and moisture distribution using finite element method. The lean meat samples (anisotropic) with three fiber configurations (v; flow normal to fiber, dry...
Citation Formats
U. Turan, “Simulation of a batch dryer by the finite difference method,” M.S. - Master of Science, Middle East Technical University, 2005.