Determiination of moisture diffusivity in porous media using moisture concentration profiles
نویسنده
چکیده
Abstract--A procedure is presented to determine the moisture diffusivity for drying from measured moisture concentratio~a profiles. From error analysis it is shown that the applied space grid for scanning and the one-dimensional resolution of the NMR (nuclear magnetic resonance) method used for the measurements had a minor influence on the accuracy of the determination of the moisture diffusivity. The inaccuracy was dominated by experimental noise and inhomogeneities in the porosity of the materials under investigation. A receding d:rying front method is presented to determine the moisture diffusivity at low moisture contents : here the moisture transport is dominated by vapour transport, which limits the overall drying rate. The method uses the velocity of the receding drying front to approximate the moisture diffusivity.
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