Heat and mass transfer characteristics in adsorption of water vapor for silica gel packed bed adsorber

Detailed study of heat and mass transfer inside a silica-gel packed bed, es pecially extraparticle diffusion for adsorption of water vapor, was carried out in a densely packed adsorbent bed, which normally prevails for realizi ng AHP technology. Experimental data for temperature and pressure distribut ions in the packed bed of adsorbent for adsorption of water vapor on silica gel is evaluated in terms of heat and mass transfer numerical calculation based on the model of water vapor transport which accounts for both heat an d mass transfer of the interparticle void and the adsorbent particle. Subse quently, the effect of particle size and the rate of adsorption are discuss ed from the viewpoint of adsorption mechanism. It is found that the model calculation was appropriate since the results we re found to agree with the experimental values. For the experimental condit ions, mean adsorption rate is found to increase with particle size under d( p) less than or equal to 500 mu m, above which the adsorption drastically d ecreases with an increase in particle size, From this result, it is conclud ed that there is an optimum value of particle size relative to the bed heig ht for attaining a maximum adsorptivity.