Abstract: Flooding hydraulics characteristic of air-water two-phase flow was studied in a miniature plexiglass structured packing column with an inside diameter of 220mm.The experiment used domestic CY700 type of stainless steel gauze corrugated packing and the differential pressure signal of the metal gauze corrugated packing layer was acquired by EJA120A miniature differential pressure transmitter at room temperature and atmospheric pressure.Distribution characteristics of the packing layer pressure was analyzed during different operation stages in the structured column.Fluctuation of the packing layer pressure showed normal distribution with distinctive feature in different experiment operation stages and a fluctuation degree of the pressure signal with standard deviationat was further studied at different spray densities in the packing column.There was a distinct difference between pre-flooding and post-flooding.The power spectral density characteristics of the packing layer pressure were obtained through the analysis of the pressure signals at different operation stages.The pressure signal power at the flooding stage was greater than at the loading liquid stage,and the pressure signal power at the normal operation stage was the minimum.Control of the differential pressure distribution characteristics signal at real-time monitoring could adjust the operation state of the packing columns in real time to predict and avoid the occurrence of flooding,improve operation performance and economic efficiency of the packing columns to realize energy saving and emission reduction.

Key words: structured packing column, gauze corrugated packing, flooding, hydraulic performance

摘要： 在炼油、石油化工、精细化厂、食品及医药等部门,塔器均属量大面广的重要单元设备,其投资—般占投资总额的20%左右,有些甚至高达50%,塔器广泛应用于蒸馏、吸收、萃取、洗涤、传热等单元操作中。因此塔器的研究一直受到国内外学者普遍关注。由于规整填料塔具有效率高、压降低、放大效应不明显等优点,使其应用越来越广泛^[1-2]。同时填料塔也是过程工业中能量消耗最大的单元操作之一。在设计填料塔时,一般按液泛气速的60%~70%确定载点气速,按液泛气速的50%~60%确定操作气速。尤其在工业实际应用中,大部分操作都是依据长期积累的操作经验使填料塔工作在所谓的"最优化"操作状态,因此填料塔的操作状态都比较保守,目的都是为了避免塔器在长周期运行过程中发生液泛而停产,给企业带来经济损失。液泛现象一直以来都是制约填料塔设计和提高填料塔能量利用率的瓶颈问题,所以关于预测控制填料塔液泛性能的研究是填料塔优化节能研究的关键^[3-4]。只要能对填料塔的操作状态进行实时监控,根据填料塔工作监控的特征参数,可以实时和及时地调整填料塔的操作性能,从而避免填料塔发生液泛,同时根据工艺和生产的需要实时改变填料塔的操作性能,使得填料塔工作在最优化的状态,也符合节能减排的目的。有关填料塔液泛水力学方面的研究已经有很长一段时间。早期的很多研究者都是从散堆填料的研究推广到规整填料的研究,Sherwood等^[5-6]在测定填料塔水力学压降实验的基础上,讨论了填料塔的载液和液泛现象,并提出了压降通用关联图(GDPC)。Eckert等^[7-9]得到了不同填料类型填料塔水力学压降液泛曲线图。Kuzniewska-Lach^[10]以量纲1方法对填料塔流体物性和填料几何参数进行了分析,提出了基于填料类型的泛点预测。Ondracek等^[11]通过填料塔气体或液体入口速度周期性波动操作,进行了液泛滞后效应的实验研究,对工业塔操作更接近液泛点有一定的指导作用。根据上面的这些研究,分析预测填料塔液泛特征的规律,需要从不同方面进行深入的研究。本文以空气和水为实验介质,研究了规整填料塔在各个操作阶段的水力学特征及区别,得到了填料塔液泛水力学压降离散特征分布规律和压降频率分布规律,为预测控制填料塔液泛现象提供了指导。

关键词: 规整填料塔, 丝网波纹填料, 液泛, 水力学性能