Simulation of paper-drying systems with incorporation of an experimental drum/paper thermal contact conductance relationship

Journal Article · Wed Dec 01 04:00:00 EST 1993 · Journal of Energy Resources Technology

DOI:https://doi.org/10.1115/1.2906435· OSTI ID:142378

Asensio, M C; Seyed-Yagoobi, J ^[1]

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1. Texas A and M Univ., College Station, TX (United States). Dept. of Mechanical Engineering

A theoretical model for simulation of conventional steam-heated cylinder dryers is developed by considering the heat and mass transfer in a porous sheet during drying. Expressions for sheet shrinkage as a function of mass of water removed and for reductions in sheet porosity are derived for inclusion in the model. The interface thermal contact conductance of moist paper handsheet/metal interfaces has been experimentally investigated. A resulting empirical correlation, representing the thermal contact conductance between the cast iron dryer surface and paper web, is incorporated into the drying simulation model to reflect reductions in heat input to the sheet during drying. Finite difference techniques are used to obtain the numerical solutions. Average sheet moisture content and temperature along the length of the dryer section as well as average evaporation rates per cylinder are predicted by the model. Consideration of the internal dynamics of the drying process allows profiles of sheet moisture content, temperature, liquid flux, and vapor flux through the sheet thickness to be developed throughout the dryer section. Drying results are consistent with actual production cases. The model can be used to design dryer sections, study changes in operating conditions or in layout of a multi-cylinder dryer, or simulate the application of enhanced drying devices to a conventional drying section. The effect of the drum/paper contact conductance on drying rates and resultant dryer section requirements is provided as an example application of the model.

• Sponsoring Organization: USDOE
• OSTI ID: 142378
• Journal Information: Journal of Energy Resources Technology, Journal Name: Journal of Energy Resources Technology Journal Issue: 4 Vol. 115; ISSN 0195-0738; ISSN JERTD2
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
COMPUTERIZED SIMULATION
DRYERS
DRYING
ENERGY CONSERVATION
MATHEMATICAL MODELS
OPERATING COST
PAPER