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Drying with internal heat generation: Theoretical aspects and application to microwave heating
Author(s) -
Constant T.,
Moyne C.,
Perré P.
Publication year - 1996
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690420206
Subject(s) - internal heating , boiling , mass transfer , heat transfer , mechanics , microwave , microwave heating , capillary action , porous medium , thermodynamics , porosity , materials science , nuclear engineering , chemistry , composite material , engineering , physics , telecommunications
Abstract A model of simultaneous heat and mass transfer presented describes drying with internal heat generation. Since a liquid expulsion phase is observed, a numerical procedure was developed to account for saturated and unsaturated zones and to model the liquid expulsion. The model was validated by a drainage experiment. An experimental rig was built to conduct microwave drying experiments in well‐controlled conditions using capillary porous body (light concrete) as test material. Two types of drying (high and low power) were distinguished, depending on whether or not boiling occurred in the sample. The heat source term in the medium was determined from the experimental results. The numerical results agree with the experimental observations in terms of drying kinetics and transfer mechanisms. This allows a very accurate description of the transport phenomena and the liquid expulsion phase associated with high‐power drying.