Abstract: This paper presents the residence time profiles for single-pass and two-pass liquid flows by tracer technique for a water/air system in an experimental semicircular sieve tray of 2 meters in diameter. Analysis of residence time profiles indicates complicated flow pattern for single-pass flow. For two-pass liquid, similar flow pattern is observed from the residence profiles on center downcomer tray, while relatively uniform convergent flow is found on side downcomer tray. A mathematical model based on residence time profiles for single-pass tray is presented to compute the concentration profiles and the enhancement ratio, i. e. the ratio of the Murphree tray efficiency to the point efficiency. The average deviation between the predicted and the experimental tray efficiency found in literature is less in present model than the other existing models. Similar modeling for two-pass liquid flow is also presented including central downcomer and side downcomer tray, the proposed model agrees closely with recently published results. Finally, this paper introduces two kinds of new constructions on the experimental tray, which have shown successful improvement on the uniformity of liquid flow. These constructions are simple, practical and capable of increasing tray efficiency considerably.

摘要： 在2米半园筛板试验装置上,用多点电导连续测量和微机数据采集系统研究了单、双溢流塔板的液体停留时间分布和流动型式.得到的等平均停留时间分布图表明,单溢流塔板上液体流动型式相当复杂.在双溢流板中,中央降液管塔板的流动情况与单溢流板的前半部相似;边降液管板的液体流动则要均匀得多.本文建立了由液体等平均停留时间分布曲线计算单、双溢流塔板板效率的数学模型,并给出了关系图.最后,本文提出两种改善液体流动均匀性的新结构,实验证明它们能够明显地提高板效率.