A quartz crystal microbalance (QCM) technique was used to measure amounts of adsorbed and desorbed water vapor in a moist air to a thin layer of adsorbent consolidated with silica-gel micro particles on the quartz crystal coated with thin gold electrodes. First, measured relative isothermal equilibrium adsorption was confirmed to reproduce the catalogue data of the silica gel. Then, the adsorption and desorption rates to the layer were measured under a condition of a step change of the surrounding relative humidity. Overall mass transfer resistance which related to both the mass diffusion in the particle and the mass transfer in the boundary layer was revealed by the obtained time constants of these reactions. The resistance decreased with the increase of the velocity, and it became a negligible quantity in the boundary layer when the flow rate was above 0.1 m s−1. Finally, correlations were proposed to predict these resistances.
All Science Journal Classification (ASJC) codes
- Building and Construction
- Mechanical Engineering