Experimental study on heat and mass transfer in packed beds adsorbing steam

Experiments were performed on heat and mass transfer in one-dimensional thin packed beds of silica gel A and zeolite 13X adsorbing steam. The adsorption rate decreased in both the silica gel and zeolite beds as the bed thickness increased, while the reduction of the adsorption rate with decreasing the adsorbent grain size was found only in the zeolite bed. It was confirmed that these reductions were attributed partly to a non-negligible resistance to mass transfer in the interstices of grains, in addition to a resistance to heat conduction within the bed. There was an optimum bed thickness in which the amount of adsorbed water per unit area of heat transfer surface became maximum, because it depended on the adsorption rate and the amount of packed adsorbent. In a consolidated bed, an improvement of adsorption rate was observed in the latter half of the reaction period. The adsorption rates at various conditions could be expressed by a single non-dimensional equation.