PREDICTIVE MODEL FOR LEATHER DRYING BY DIFFERENT TECHNOLOGIES

摘要

Predictive models for drying kinetics were developed for three of the main industrial leather drying technologies (toggle drying, natural drying and vacuum drying). These models are useful tools to predict the effect of process variables on drying evolution as well as for process control.Experimental data for different conditions of toggle, natural and vacuum drying were obtained and computer programs were developed to determinate models parameters.Proposed models provide a description of the process based on mass and energy balance as well as on transport phenomena equations. The best models obtained for toggle and natural drying, indicated that convective heat transfer between air and leather controls drying rate.For vacuum drying, the best model showed that diffusion of water within leather controls the rate of drying process. The models developed allow predicting variations of moisture content during leather drying with errors under 3.0%, 0.4% and 8% for toggle, natural and vacuum drying respectively.