CFD and experimental studies of liquid weeping in the circular sieve tray columns

• The liquid weeping in a circular distillation column with diameter of 1.22 m was studied.
• Behavior of weeping along the tray, influence of gas and liquid flow rates on weeping and some hydraulic parameters in weeping range were investigated.
• A successful full 3D CFD model was developed to predict weeping and several hydraulic terms.
• The chimney tray was considered in computational domain.

Sieve trays are widely used in fractionating devices like tray distillation towers existing in separation and purification industries. The weeping phenomenon that has a critical effect on the efficiency of tray towers was studied by a numerical model and some experiments. The experiments were carried out in a pilot scale column with the diameter of 1.22 m that includes two test trays and two chimney trays. Weeping rates and some hydraulic parameters were measured in sieve trays with the hole area of 7.04%. Furthermore, the total weeping rate and weeping rate in inlet and outlet halves of the test tray were determined. It was also used an Eulerian–Eulerian computational fluid dynamics (CFD) method for the present study. The model was able to predict the dry tray pressure drop, total pressure drop, clear liquid height, froth height, and weeping rate simultaneously. Furthermore, the obtained CFD results were in a good agreement with the experimental data in terms of pressure drop and the model properly predicted several hydraulic parameters like the liquid weeping behavior along the tray.