Abstract
The present work consists of the simulation of a sieve tray using CFD for the air-water system, comparing the results obtained of the clear liquid height (hcl), with the experimental data, adjusting and varying different characteristics. The investigation has two general steps: the first step was to modify the Grace Drag Model (GDM) based on experimental data of clear liquid height for different superficial gas velocities (Vs). Once this was achieved, in the second step were established the effects of different variables on the clear liquid height as: 1) type of geometry (2D and 3D), 2) height of the weir (hw), 3) liquid load per weir length (QL/W) and 4) superficial gas velocity; in all the cases of the second step, the modified drag coefficient obtained in step 1 is used. Verification of predicted values for clear liquid height with experimental data demonstrated the accuracy of the proposed modeling in the modified drag coefficient. Results showed that the interphase momentum exchange (drag) coefficient can be estimated by the fitted GDM, concluding that Bennet correlation is not necessary to estimate gas hold-up as it is used in most research involving CFD to simulate sieve trays. The percentage of error in the proposed CFD model was around 3.42 % compared with the 40.0 % average reported in previous studies. These results generate new guidelines toward best practices for modeling the hydrodynamics in sieve trays.
