气液两相逆流状态下金属板波纹填料塔内液体流动分布

<正>填料塔内液体流动分布状况直接关系到塔内气液两相的有效接触,影响塔的操作性能.由于液体分布不良,造成填料塔内局部区域的气液比与全塔宏观的气液比有显著差别,从而大大降低塔的总传质效率.因此,填料塔内的液体分布     

现代化学工业中填料塔技术的应用

填料塔是化工工业中最常见气液分离设备之一,本文介绍了选择填料塔的设计条件,论述了当前最新的塔内填料、液体分布器、进气初始分布器的分类及各自特性。     

填料塔基础理论研究新进展

规整填料塔具有效率高、压降低、放大效应不明显等优点,其成功应用有赖于对二相流动与传质的深入认识。文中综述了规整填料塔内的气液二相流动与分布、返混、气液二相在常压和高压下的传质特性、M arangon i效应以及计算流体力学(CFD)在规整填料塔中的应用等方面的国内外研究进展。填料塔内液体的分布与返混的研究较多,气相的流动分布与返混特性的研究较少,高压传质、M arangon i效应,特别是利用计算流体力学(CFD)模拟填料塔内的液体流动与传质等已逐渐成为研究的热点。     

工业规模板波纹填料床层的液体分布

采用φ480mm,高6 m的工业规模有机玻璃填料塔,以空气-水为实验物系,测试了250 Y型金属孔板波纹填料床层的液体分布.空塔气速和液体喷淋密度的测试范围分别为0.677～2.062m/s和27.37～109.2m3/(m2·h).结果表明,液速和气速的改变均不会对床层液流分布造成较大的影响,而壁流量受塔内气液流动的影响较大.     

新型规整填料及填料塔内件

概述了国内外十多年来开发成功的新型规整填料及填料塔内件 (新型气液分布器、填料塔进气初始分布器 ) ,并对其性能及工业应用情况作了简要介绍。     

规整填料塔气液传质基础理论研究进展

填料塔中气液两相的流体流动与分布、返混、传质问题一直是影响填料塔传质性能的重要因素,对规整填料塔内的气液两相流动与分布、返混、气液两相在常压和高压下的传质特性、Marangoni效应以及计算流体力学(CFD)在规整填料塔中的应用等方面的国内外研究进展进行了综述.     

海水脱硫散堆填料塔的数值模拟及传质计算

采用体积平均法建立了描述散堆填料塔内气、液两相的流动模型;在双膜理论的基础上建立了平均体积传质模型。通过数值计算,获取了在不同液气比下塔内流体速度、孔隙率分布、压力分布及脱硫效率,并就压力损失和脱硫效率与实验值进行了对比,预测值与实验值吻合较好,趋势完全一致。分析填料塔内海水的速度分布矢量图和填料塔中间高度断面上的速度分布图发现,靠近壁面处存在着显著的壁流现象,并在沿流方向上液体有向壁区积聚的趋势,壁流现象变得更严重。由3种填料径向孔隙率分布图可看出,近壁面处的孔隙率明显高于中间区域,表明这是形成壁流的原因所在。     

等几率并螺旋填料塔的研究

为解决了高效填料塔的放大效应问题,研制了等几率并螺旋填料塔,其具有传质效率高、压降低的特性,集成毛细管气液分配器使填料塔内液体初始分布均匀,克服了高效填料塔的壁流效应。2-甲基丁醇和3-甲基丁醇的工业化分离实验表明,该填料塔不存在放大效应,可用于难分离物系的精馏。     

板波纹填料塔中的液体分布

根据透明有机波纹填料片内染色液体流动分布的实验研究 ,提出了板波纹填料塔内液体流动模型 ,并对真实填料塔进行了实例计算 ,所得结果对于填料塔实际操作具有指导意义     

一种新型单体填料性能的研究

一种新型单体填料性能的研究陈伟琳，肖如亭（天津理工学院天津３００１９１）１．前言填料塔是应用在化工生产中的塔型之一，它已成为主要的气、液传质的设备之一。而填料塔的发展和改进，主要反映在填料的发展和改进上。填料是填料塔的核心组成部分，为塔内气、液两相接...     

规整填料塔内气-液两相并流流动的CFD研究

应用FLUENT,即一款流体力学计算软件,对规整填料塔内的气液两相并流流动时的液相分布进行了研究,用数学方法拟合出压降和持液量之间的定量关系,并通过实验进行了验证。基于Mellapak350Y填料建立了物理模型,采用的方程是RNG k-ε湍流模型封闭动量方程。模拟过程中引入了表面张力源项以及相间作用力源项。模拟结果和实验结果吻合良好,表明了求解规整填料塔内两相并流流动的方法是合理的。     

Liquid Flow on Structured Packing: CFD Simulation and Experimental Study

A CFD model of the two‐phase countercurrent flow in the geometry of the plate‐type structured packing Mellapak 250.Y was built, tested and verified. The model was applied to determine the effect of liquid and gas flow rates and physicochemical properties of the flowing liquids on the interfacial area formed on structured packing. The CFD model allowed us to determine the minimum liquid flow rate at which an unbroken liquid film was observed on the packing surface. The simulations confirmed that with an increase of the wetting rate the surface of the packing covered with a liquid film increased until the surface was totally covered up, while further slight changes of an interfacial area were the result of wave formation. The effect of gas load (F factor) on the film surface was in the range of a calculation error. Results of the CFD simulation allow us to predict the stages of film formation during liquid flow, to follow local velocity oscillations, film thickness and velocity profiles of phases.     

规整填料单元内流场的三维LDV测量

引言 近二三十年,规整填料已广泛应用于反应、分离和混合等各类化工设备中,但对于规整填料内部流体流动规律的深入研究目前仍比较缺乏.以气液传质设备为例,规整填料塔内流体的流动分布会直接影响塔的传质性能,因此,国内外很多研究机构在这方面做了大量的研究,但绝大部分研究集中在宏观流动模型的建立及其实验验证方面[1-5].     

从浓度分布评价填料塔性能

精馏塔性能的优劣通常可以用在塔顶和塔底取样,然后计算其分离效率的方法来判断,但这种方法只可以判断出精馏设备效率的高低,却几乎无法找出造成设备效率不够理想或低效的原因．不良初始分布、壁流、沟流和溪流、端效应以及气相或液相返混等现象都可以造成填料塔效率的下降,而     

规整填料塔液相流动的计算流体力学模拟

规整填料因具有诸多优异性能,已在工业上广泛应用,但是至今人们对规整填料内流体流动机理的研究还不是十分透彻,从而限制了其进一步的发展和更新．与散堆填料不同,规整填料在结构上既有规整性又有复杂性,属各向异性,因此对其内流体流动的研究具有一定的难度．而现代计算流体力     

Imaging of Fluid Dynamics in a Structured Packing Using X‐ray Computed Tomography

For the investigation of fluid dynamics from computed tomography (CT) images, an evaluation method was developed that enables data acquisition directly from the recorded CT images. A segmentation algorithm was implemented in Matlab to assign every component a specific gray value. A comparison of weight experiments with CT scans and following segmentation demonstrates the good accuracy of this method. The liquid holdup in different Mellapak 500.Y packings was determined through CT measurements and compared to predictive correlations from the literature. Three‐dimensional visualizations of short packing sections enable an evaluation of the liquid distribution and the flow morphology of the liquid in the packing. The common assumption of an evenly wetted packing surface with a constant liquid film thickness could not be proved.     

Experimental investigation of liquid holdup in structured packings

Liquid holdup is an important hydrodynamic parameter for characterizing the gas/liquid flow pattern in packed beds. In this paper, a study of liquid holdup in 3 different structured packings: Mellapak 2X from Sulzer, Koch-Glitsch Flexipac 2Y HC, and Montz-Pak B1-250M is presented, using air/water, air/water/sugar solutions with liquid viscosity up to 12 cP and air/30 wt% MEA in a 0.5 m ID absorption column with a packing height of 5 m. As expected, at a given liquid load, the liquid holdup was close to constant as a function of gas flow, with an increase at high gas velocities. In general, the Sulzer packing had a higher liquid holdup than observed in the two other packings. A possible explanation for this could be the lack of enhanced draining of liquid as seen with the modifications of the end-section of the Koch-Glitsch and Montz packings. Liquid holdup was found to increase with increasing liquid viscosity. The influence was higher at high liquid load than at low liquid load. Our results indicate a higher dependency at high liquid load and a lower at low liquid load. There was a reasonable agreement between our results and the data found in the literature.     

加压下填料塔中液相轴向反混的研究

Liquid phase axial mixing was measured with the tracer technique in a packed column with inner diameter of 0.15m,in which the structured packing,Mellapak 350Y,was installed.Tap water as the liquid phase flowed down through the column and stagnant gas was at elevated pressure ranging from atmospheric to 2.0MPa.The model parameters of Bo andθwere estimated with the least square method in the time domain.As liquid flow rate was increased,the liquid axial mixing decreased.under our experimental conditions,the effect of pressure on Bo number on single liquid phase was negligible,and eddy diffusion was believed to be the primary cause of axial mixing in liquid phase.