CFD Simulation Of Hydraulics Of Dividing Wall Sieve Trays

Distillation is a high energy consumptive unit operation of petrochemical industry.In these years, energy prices continue to rise, so energy-saving research of distillationprocess is of great significance. As a focus of this field, dividing wall columns (DWC)are being promoted in many developed countries these years. Theoretical studiesshowed that the columns can reduce energy consumption by30–50%overconventional distillation sequences. But research of hydraulics of dividing wallcolumns is not so sufficient. There are two ways to research tray hydraulics:experiments and computer simulation. Results of tray hydraulics experiments areaccurate and reliable, but the cost of money and time is huge. With the developmentof computer technology, computer simulation of distillation trays based on CFD hasbecome an important method of distillation design. Results of CFD simulation can notonly show microscopic information of the flow, but also be used in real-worldproductions.In this paper, CFD simulations are carried out to research hydraulics of dividingwall columns. A3D two-phase CFD model containing gas mal-distribution isdeveloped in the Eulerian framework. Simulations of flow patterns and hydraulics ofa commercial-scale1.2m diameter sieve tray are carried out using CFD softwarefluent with water-air system to testify precision of the model. Then, simulations of adividing wall sieve tray with equal diameter are carried out in the same workingconditions to research hydraulics of dividing wall columns.Simulation results show that the CFD model in this paper is of good precision.Comparison between simulation results of conventional trays and dividing wall sievetray shows that flow fields of dividing wall trays and conventional trays with the samediameter are very similar, so that experimental date of conventional trays can be usedin designing of dividing wall trays.