Experimental Study And Numerical Simulation Of A Novel Directed Fixed Valve Tray

Tray column is a type of commonly used gas-liquid contact equipment, the fixed valve tray is a widely used tray that integrate the advantages of sieve trays and valve trays and overcome some of the shortcomings of the plate of the different kinds of trays. Its performance is excellent and there are a lot of researches and development prospects. Based on the existing researches of trays, in order to strengthen the guiding function of liquid on the tray and inhibit the entrainment, a new type of fixed valve tray is developed in this work—low entrainment directed-trapezoidal fixed valve tray. Therefore, the hydrodynamic performance and gas-liquid flow field on plate of this novel fixed valve tray were studied and analyzed by lab experiments and CFD simulation in this paper.In experiments, the hydrodynamic performances of the novel tray were carried out by using air-water system in a rectangular tower of 1500×400mm at room temperature and atmospheric pressure. The hydrodynamic performances parameters comprising pressure drop, clear liquid height, entrainment and weeping were measured by adjusting the experimental parameters. Correlations of plate pressure drop, clear liquid height, entrainment and weeping with liquid strength, kinetic energy factor based on valve holes and weir height were obtained. And these will provide some basic supports for future researches. Compared with F1 valve, the new tray's dry pressure drop is 30-40% lower and wet pressure drop is 10-20% lower, entrainment is 60-70% lower. Compared with half-ellipse fixed valve, the new tray's pressure drop is a bit higher, entrainment is 40-50% lower, the entrainment is restrained obviously.In simulation, a CFD model was set up with the help of software Fluent to study the flow field on the tray. Based on the Eulerian framework as two interpenetrating phases and a mixture turbulence model that is based on the k –? equations, a proper three-dimensional model for the tray was established. Interaction between the two phases occurred via interphase momentum source was calculated by the experimental data. To prove the correctness of the CFD model, the clear liquid height was simulated under the same situation and the results was compared to the experimental data. The result shows that the clear liquid heights predicted by these simulations were in good agreement with the experimental data, so the analysis on the gas-liquid hold-up and velocity fields were implemented in detail. Furthermore, how the flow field was impacted by the construction can be known.