Hydrodynamics and mass transfer performance of vapor–liquid flow of orthogonal wave tray column

LuhongZhang, ZhijieLi, NaYang, BinJiang, HaifengCong, ZhihengZhang

School of Chemical Engineering and Technology, Tianjin University, Tianjin, P. R. China

Collaborative Innovation Center of Chemical Science and Engineering, Tianjin University, Tianjin, P. R. China

National Engineering Research Center of Distillation Technology, Tianjin University, Tianjin, P. R. China

Highlights

  • A novel dual-flow orthogonal wave tray was developed.
  • Hydrodynamics and mass-transfer performance of vapor–liquid flow of orthogonal wave tray column were studied by means of experiment and CFD simulation, which present potential uses in capacity expansion.
  • The simulation results exhibit all of the known features of the two-phase flow field and mass-transfer performance on distillation trays and are in good agreement with experimental results.
  • The validated CFD model was used to investigate the hydrodynamics and mass-transfer performance of OWTs with different waves.

Abstract

In the present work, hydrodynamics and mass-transfer performance of vapor–liquid flow of orthogonal wave tray (OWT) column was studied. Dry pressure drop, operating range (capacity graph) and overall column efficiency of OWT column were investigated using pilot columns. A three-dimensional CFD model was developed within the two-phase Eulerian framework to have an insight into the two-phase flow and mass-transfer behavior of OWT. The simulated results were compared with experimental data and showed a good agreement. Hydrodynamic and mass-transfer behaviors were revealed with the aid of velocity profiles, streamlines, interfacial area density distribution and so on. The effects of vapor/liquid load (FS factor) on the Murphree tray efficiency were also studied. The simulations of OWT with different waves showed that the pressure drop, clear liquid height, froth height and Murphree tray efficiency increase with the increase of slope, and OWT with middle slope tended to have more uniform foam layer. Comparison of the liquid-phase component velocity between OWT and ripple shows that OWT has better performance in froth layer distribution and stability. The mass-transfer data showed that OWT not only had almost the same “peak efficiency” as sieve tray, but also had higher capacity and stability, it was suitable for capacity expansion.

Graphical abstract

Keywords

Orthogonal wave tray; Downcomer-less tray; Multiphase flow; Mass transfer; Tray efficiency

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