The Influence of External Resistance on Moisture Adsorption Rates in Wood


  • Howard N. Rosen


Juglans nigra, Acer saccharinum, diffusion, air velocity, moisture, adsorption


Dry specimens of black walnut and silver maple, end- or side-coated to restrict moisture movement to the radial or longitudinal direction, were subjected to adsorption at 97% relative humidity at 25 C. The specimens of 0.7-, 1.6-, and 2.7-cm thickness were moved through humid air at velocities of 0.4 to 11.7 m/s by rotating them on carrousels at various speeds to determine the influence of external resistance on moisture adsorption rates. Adsorption rates were considerably increased by increasing the wood velocity through the air up to 3 m/s, but the benefits of increasing wood velocity to increase adsorption were reduced above this velocity. The relative importance of external resistance to moisture movement in wood increased as wood thickness and/or velocity decreased, and was greater for longitudinal than for radial flow.


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