Distillation Column Tray

Description: Distillation column trays are one of the most important pieces of equipment in clean water treatment, chemical separation, and process engineering, working by bringing rising vapor into direct contact with falling liquid on a perforated tray so volatile components evaporate while heavier components condense and drain. This project focuses on the hydrodynamic two-phase behavior of air and water at the tray location, examining how the two phases interact, mix, and separate, without yet introducing heat transfer or evaporation effects.

Methodology: A symmetrical 3D tray column geometry is built in Design Modeler, modeling only half the chamber to reduce computational cost, and meshed with an unstructured grid of roughly 866,000 elements suited to two-phase tray flow. The VOF multiphase model is configured with air as the primary phase and water as the secondary phase, using implicit formulation and sharp interface modeling, alongside mixed boundary conditions of a velocity inlet for gas at 23.35 m/s, a mass flow inlet for liquid at 4 kg/s, and pressure outlets for both phases. Turbulence is captured with the RNG k-ε model and standard wall functions to handle the swirling, separating flow, with PRESTO! pressure discretization and the Modified HRIC scheme for volume fraction, and the domain is initialized with a patched water region to start from a realistic phase distribution.

Analysis: Post-processing includes pressure contours, velocity contours, phase volume fractions, and velocity vectors across both 2D cross-sections and 3D views, capturing how the vapor and liquid phases distribute and interact across the tray. Since distillation columns underpin desalination plants, wastewater treatment, and petrochemical refineries alike, this hydrodynamic groundwork provides a portable, industry-relevant foundation for tackling multiphase separation problems in real process equipment.