The schematic of a vortical contact stage is presented for heat- and mass-exchange processes, and possible flow regimes of the gas-liquid layer are analyzed. Equations for calculation of the critical gas velocity ensuring conversion to an annular flow regime of the gas-liquid mixture, and relationships between the Sherwood and Reynolds numbers are derived. The Murfree efficiency of the vortical contact stage is evaluated. Relationships between the coefficient of convective heat exchange during boiling in the rotating layer on the specific heat load and centrifugal criterion are obtained.