CFD simulation of sieve-fixed valve tray hydrodynamics

Abstract

In this work, the sieve-fixed valve (SFV) tray was designed by adding flow-guiding and sieve holes on the valve caps of the original trapezoid valve (OTV). A computational fluid dynamics (CFD) model of three-dimensional two-phase flow was developed to describe the flow structure of SFV tray. Based on the experimental clear liquid height, the modified correlation of Bennett was adopted for liquid–gas interaction and the ga–liquid momentum transfer term MGL was also obtained. To demonstrate the function of flow-guiding hole and sieve hole, the hydrodynamics of the OTV and SFV trays including pressure drop, weeping, entrainment and clear liquid height were experimented and compared. What’s more, local information such as velocity profile and flow field around the valves were simulated. CFD results showed that the new valve tray with flow-guiding holes was capable of promoting liquid flow and homogenizing liquid flow. This study proved that CFD research can test modification of devices, and provide information which could not be obtained by experiment. The CFD method tends to be a necessary part for designing and modifying new distillation internals.