【作者】 江山；

【导师】 胡大鹏；

【作者基本信息】 大连理工大学 ， 化工过程机械， 2015， 硕士

【摘要】 本文旨在提高塔设备的气相处理量,设计了一种新式板式塔结构,称之为高速塔。高速塔利用旋流接触元件内气体速度高和气液分离效率高的特性,将其移植到塔板上,并设计新式的进液通道,让液体直接进入叶片中心。液体从叶片出口流出后,立即与气体接触传质,并在气流的旋转作用下,实现离心分离。这种新式结构,改变传统的气液接触方式鼓泡式为喷射式,使气相保持为连续相与分散的液相接触。由于气液的接触传质与分离过程同时发生,塔板空间得到了充分利用。首先对单个旋流接触元件进行数值模拟分析,得到了旋流接触元件内部气相流场的一些特性：(1)轴向速度沿径向向外先减小后增大,这将导致气体的回流,使得气液能够反复接触传质；切向速度沿径向逐渐增大,最外侧切向速度达到最大；径向速度整体较小,这为气液提供了更充分的接触时间；(2)在旋流接触元件叶片出口中心产生的低压区和降液管液位静压的共同作用下,液体能够顺利进入旋流接触元件,并且,随着气相处理量的增大,降液管最低液位不断增大；旋流接触元件的总压降主要集中在叶片出口处。依据模拟结果,设计高速塔的具体结构,然后送加工厂进行械加工。在完成实验平台的搭建后,本文对高速塔的干床气相压降性能和湿床压降性能进行了实验研究,得到如下主要结论：(1)干床压降随气体处理量的增加而增大,各层塔板的压降由下至上逐级递减；(2)塔板湿床压降随气相流量的增大而显著增加,随液相处理量的增大而稍有增加；当气体处理量较小时,各级塔板的湿床压降大小相当,当气相处理量较大时,各级塔板的压降由下至上逐级递减。在此基础之上,本文进一步研究了高速塔的负荷性能,对高速塔的液泛、漏液和干板现象进行了实验研究,汇总气相流量和液相流量的操作范围,得到高速塔的负荷性能图,并得到以下结论：(1)随着液体流量的增加,液泛气速逐渐减小,但是漏液气速基本保持不变,液体流量下限稳定在较低水平,上限随着气体处理量的增加,稍有减小；(2)高速塔的气相处理能力较传统的筛板塔提高45.5%,最高液泛气速可达到2m/s,气体操作速度的范围最大可达到1.1-2.05m/s。更多还原

【Abstract】 Aiming at improving the throughput of gas phase, this paper devises a new plate device called high-velocity column. It takes advantage of cyclone tube, which has high gas velocity and high separation efficiency of gas and liquid, transplants cyclone tube onto the plate and designs new passage for liquid to enter the center of blades directly. So that, the liquid can contact and transfer mass with gas immediately after discharging from the exit, and make use of the centrifugal force, resulting from the rotating gas, to achieve separation. This new structure changes jet type for bubbling type, which is the tranditional way of contacting between gas and liquid. It means the gas maintains for continue phase during the contact process, while the liquid becomes dispersed phase. Also, the separation proceeds at the same time of contact, as a result, the space in the tower is fully used.At first, this paper carries out numerical simulation analysis of gas flow field in single cyclone tube, and gets some properties:(1) Because of the diversion effect of blades, the gas velocity distribution is very conductive to the gas-liquid contact and separation. The circumfluence emerges in the axial direction contributes to the repeatedly mixing, contacting and mass transferring of gas and liquid; high tangential velocity aids in the separation of droplets, reducing the entrainment; small radial velocity provides more contact time for gas and liquid;(2) Under the joint effect of low pressure area in the center of the blade outlet and static pressure of liquid level in the downcomer, the liquid could successfully enter the cyclone tube With the increasing capacity of gas phase, the downcomer minimum level increases; the pressure drop of cyclone tube mainly concentrates on blade outlet.Then, the specific structure of the high-velocity column is designed based on the results of simulation. The experiment study of performance on dry plate pressure drop and wet plate pressure drop are conducted, after machining the equipment and putting up the platform. The following conclusions can be drawn:(1) The dry pressure drop of this column improves with the increasing of gas flow rate, and the pressure drop of different layers of plate decrease from the bottom to the top;(2) With the gas flow rate growing, the wet pressure drop significantly increases, while with the liquid flow rate growing, it increases slightly; when the gas flow rate is low, wet pressure drop of the three layers of plate are almst the same,when the gas flow rate is high, the wet pressure of bottom tray is larger than the middle tray, of which it is larger than the top tray.On the basis, the load performance of high-velocity column is studied further. Experiment studies of the flooding、weeping and dry plate are conducted, the conclusions below can be obtained:(1) With the growth of liquid flow, the flooding velocity decreases gradually, while the weeping velocity almost stays unchanged;(2) There is no obvious lower limit of liquid flow, while the upper limit decreases slightly when the gas flow increases.更多还原