Stage and point efficiencies in barrier separation processes

The Murphree type stage and point efficiencies for any rate governed barrier separation process have been critically examined. Standart's plate efficiency definition and the concept of the rate of enriching mass transfer through the barrier have been utilised to propose new definitions of stage and point efficiencies in barrier separation processes with single entry separating elements. Expressions have been derived for the proposed point efficiency for various nonidealities encountered in some common barrier separation processes. An analytical relation between the proposed stage and point efficiencies has been developed for an ideal cross flow stage in a close separation barrier separation process. The procedure for estimating the proposed stage efficiency has been indicated also for a cross flow stage when the flux expressions through an ideal and a real barrier are known.