MODELING OF SUPERHEATED STEAM DRYING OF WOOD PARTICLES
K.H. Le†, T. T. H. Tran†*, A. Kharaghani‡2, E. Tsotsas‡
†School of Heat Engineering and Refrigeration, Hanoi University of Science and Technology, No. 01 Dai Co Viet Street, Hai Ba Trung, Hanoi, Vietnam
‡Thermal Process Engineering, Otto von Guericke University, PO 39106, Magdeburg, Germany
*Corresponding Author Email: [email protected]
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In this work, the superheated steam drying behavior of single wood particles at elevated temperature (i.e. 120°C, 140°C, 160°C and 180°C) are experimentally investigated by using a magnetic suspension balance system. To describe the experimental drying behavior, a coupled heat and mass transfer model of drying model is developed. The moisture diffusivity in the wood particles is determined from an inverse analysis, whereas other thermo-physical properties are measured. Two types of effective diffusivities, including moisture-dependent effective diffusivity and temperature-dependent effective diffusivity, are used to describe the moisture transport in the particles. This mathematical model is implemented and solved by using finite volume element method. Numerical results obtained with temperature-dependent effective diffusivity and moisture-dependent effective diffusivity are benchmarked by the experimental observations. It indicates that the drying behavior can accurately be described by the diffusion model using moisture-dependent effective diffusivity. Furthermore, a model-based sensitivity analysis is made to investigate the influence of drying conditions on the drying kinetics of the particles. The results obtained from the sensitivity analyses may help to optimize and customize dryer design and its operation in the future.