Hydrodynamics and Mass Transfer at the Vortex Stage and during Bubbling

Abstract

Vortex contact devices for gas introduction have been developed and studied. The devices make it possible to increase the gas and liquid loading on stages compared with valve and cap devices, to reduce the fluctuations of the gas–liquid medium on the liquid surface, and to increase the separation efficiency. Based on the experimental studies and numerical modeling, a scheme of liquid and gas motion at the stage was developed, and the velocity profiles during bubbling were calculated. The stage parameters were determined: hydraulic resistance, gas content, average surface diameter of bubbles, interphase surface area, efficiency, and mass transfer coefficients. The dependences for their calculation were presented. A vortex stage for the exhausting distillation column was designed, which provides a 1.5-fold reduction of metal consumption and increased efficiency at a velocity factor of up to 3 Pa^0.5 and spray rate of 78 m³/(h m²) compared with the standard cap plate.