悬挂式降液管自液封线的实验研究  

Experimental Study on Seal Line of Hanging-Downcomer

作　　者：李育敏[1] 俞晓梅[1] 陈平[1] 

机构地区：[1]浙江工业大学化学工程与材料学院,浙江杭州310032

出　　处：《高校化学工程学报》2005年第4期554-557,共4页Journal of Chemical Engineering of Chinese Universities

摘　　要：悬挂式降液管塔板经历了四十多年的发展。由于这类塔板的降液管悬挂于塔板下的气相空间,气体可能会从降液管底部液流孔漏入降液管,故要求悬挂式降液管能自液封。以往徐崇嗣提出的自封线以降液管几乎不漏气作为自封点。作者提出以降液管每秒漏气一次作为新的自封点标准,该标准使漏气分率小于0.1%。测定自封线的实验在300mm×200mm的有机玻璃塔中进行,物系为空气-水。实验还采用多路电导测试仪,测量了原自封线和本实验自封线在液流孔处漏气所占的时间分率。实验结果表明,新自封线适用于中等和大液气比工况,它优于原自封线,能更客观地反映悬挂式降液管的自封性能,扩大了塔板的稳定操作区。Hanging-downcomer tray has developed for 40 years, in which the hanging-downcomers are terminated in the disengagement space above the lower tray froth, so that vapor may rise up through the downcomer bottom-orifices which will cause the increase of the downcomer's load. Therefore the hanging-downcomers are required to be sealed by liquid. The previous seal line proposed by Xu is too conservative, in which the criterion of almost not allowing the vapor to leak through the downcomer was set. A new criterion of vapor leakage is proposed here in which the frequency of vapor rising up through the downcomer is allowed to be once per second, according to which, the ratio of the leaking vapor rate through the downcomer to the total vapor rate will be less than 0.1%. Using the new criterion, the experiments determining the new seal lines were carried out in a 300 mm × 200 mm plexiglass column with air water system. The muti-path conductometer was used to measure the leakage fraction of the new seal line at various vapor and liquid rates. The experimental results show that the new seal line is more reasonable than the previous one and can more objectively reflect the hydraulic performance of hanging-downcomer or enlarge the tray stable-operating range. Finally, the new seal line is more applicable to the case of operation with medium and big rate ratio of liquid to vapor.

关 键 词：悬挂式降液管 自封点标准 自封线 电导测试仪 

分 类 号：TQ053.5[化学工程]