A Study on Chimney Type Centrifugal Tray Lower Operating Limit

Abstract

In this work, a computational fluid dynamics (CFD) model is developed to predict the hydrodynamics of industrial-scale Centrifugal tray that is a new kind of tray and can be used in distillation and absorption towers. Three-dimensional two-phase flow of gas and liquid is considered in which the interaction was modeled based on the concept of phasic volume defined in the Volume of Fluid (VOF) multiphase model through k-epsilon Simulation. All governing equations including surface tension and wall adhesion are solved simultaneously using the FLUENT code. Gas-liquid interfaces and the existence of froth regime are clearly visualized via VOF model. Due to the importance of trays, it is vital to predict lower operating range limits for such gas-liquid contacting devices. Weeping phenomenon is observed in bubbling regime and occurs at low vapour flow rates. To approach this aim, continuity and momentum equations are solved simultaneously for the fluid on tray and the results were compared with data of sieve trays. In the Comparison of sieve type trays with centrifugal chimney type, in low loading vapour, no weeping was observed in the centrifugal tray. The simulation results show that this innovated centrifugal tray can be used for solving the weeping problem and increasing the performance of tray towers.