Mass transfer in foam and froth regimes in distillation with sieve tray column

An experimental study on separation performance of sieve tray column in bin ary and ternary distillation is made under total reflux conditions with dif ferent tray specifications. Two different flow regimes are observed on the tray in different concentration regions for the ethanol-water, ethanol-benz ene and ethanol-benzene-water systems. The liquid holdup in the foam regime is well correlated in terms of the weir height, free area and vapor phase Reynolds number. Although higher mass transfer rate is observed in the foam regime than that in the froth regime, the dimensionless volumetric vapor p hase diffusion flux in the foam and froth regimes are well correlated in te rms of the ratio of Froude to Weber number, free area and vapor phase Reyno lds number.