5. Conclusion
The liquid weeping as a key element in performance of trays was investigated by the experiments and CFD model. A bunch of tests were carried out by the experimental tower in industrial scale where the experimental tower had two Nye trays and two chimney trays. The area of holes was 5% (based on total area).
The weeping in outlet and inlet sections of the tray and the total weeping rate were experimentally determined. It was found that the weeping rates in the inlet section of the Nye tray are higher compared to the outlet half of the Nye tray for low liquid flow rates where weeping rates were greater in outlet half of the Nye tray for middle and high liquid flow rates. Moreover, the difference between the weeping rate from downstream and upstream of the Nye tray reduces by increasing the gas flow rate. Moreover, higher gas rates provide low weeping rates along with the tray, which may result in increased tray efficiency. Besides, it was observed that taller weir height increased weeping rate unless at high liquid rate. Through a limited comparison between Nye tray and the same sieve tray, it was revealed that weeping rates in the inlet of the sieve tray were higher compared to the outlet of the sieve tray. But concerning the Nye tray, weeping rates in the downstream were very larger rather than those in the upstream. It is noteworthy that some weep can be endured without noticeably affecting the tray efficiency. Some mass transfer from and to the weeping liquid happens to reduce the effect of bypassing on efficiency. Weeping from the exit section of the tray is not detrimental to tray efficiency to some extent compared to weeping from the inlet of the tray and is endured to a much higher level [3]. Regarding this issue, it is demonstrated that the Nye tray is suitable for operating in high liquid rates where weeping rates tend toward the outlet half of the Nye tray. Overall, it seems that the inlet panel of the Nye tray makes a higher capacity for tray where it leads to very low weeping rates from the inlet of the Nye tray. This specification is a positive point of Nye tray and may provide high efficiency compared to a sieve tray.