ABSTRACT
Equilibrium effects can, in many instances, be quickly calculated and provide precisely the kind of information one needs for preliminary performance estimates. Under equilibrium conditions the mass transfer zone disappears and the sorption front propagates as a rectangular discontinuity. The sorption front stabilizes to an S-shaped, or "constant pattern" form, which results in a division into sections of saturated and clean bed, separated by a mass transfer zone represented by the S-shaped curve. Zeolites recommend themselves particularly for "deep drying", i.e., the attainment of low dew points required in cryogenic liquefaction operations. The alumina and silica gel layers serve to remove the bulk of high humidity moisture by virtue of their high capacities in that region, the zeolite playing the role of final scavenger of moisture. The greater efficiency of this mode is somewhat offset by the greater operational complexity of composite beds.
