不均匀漏液对精馏塔板效率的影响

在塔板上液体二维不均匀流动和二维涡流扩散模型基础上,建立了不均匀漏液时计算塔板效率的数学模型,并比较了均匀漏液和工业实践中常遇到的2种不均匀漏液对塔板效率的影响,计算结果表明,不均匀漏液对塔板效率及塔板操作气速的下限将产生更为不利的后果.     

塔板不均匀漏液的规律及对板效率的影响

Experiments demonstrated that the weeping is mal-distributed and occurs mainly in a region of tray deck next to the inlet weir. The amount of weeping in this region depends on the weeping rate. On this basis, three types of weeping distribution are proposed. The effect of real-distributed weeping on the Murphree tray efficiency is evaluated by using the three-dimensional non-equilibrium mixing pool model, where the influences of the flow pattern and the variation of Murphree point efficiency on a tray are taken into account. The calculated results reveal that the extent of Murphree tray efficiency drop depends chiefly on the degree of mal-distribution and the percentage of weeping. It is also demonstrated that in the determination of the lowest operating limit of vapor velocity, the unfavorable effect of real-distributed weeping should be considered as an important factor and cannot be ignored.     

漏液的不均布对塔板效率影响

依据液体二维不均匀流动、二维涡流扩散模型，建立了在给定汽液平衡关系式条件下，提出了一个不均匀漏液对板上液体浓度分布影响的数学模型，在此基础上，采用差分法对该模型进行求解。讨论了在不同的参数（包括）下不均匀漏液对板效率的影响，以图表的形式给出。结果表明，漏液的不均布确实会对板效率产生重大影响，在计算板效率时应以漏液不均匀为条件。     

影响精馏塔板效率因素探讨

塔板效率是实现产品分离的关键因素，本文详细介绍了泄漏、雾沫夹带、塔板的液向泛混等因素对塔板效率的影响，并对导出的计算板效率的经验关联式进行了分析，提出了提高塔板效率的几点建议。     

风载荷对精馏塔分离效率的影响

以乙苯－苯乙烯精馏塔为例，探讨了风载荷对较高塔器分离效率的影响。作者统计了当地两个不同月份的风级气象资料，用曲线标绘出了乙苯－苯乙烯塔顶部苯乙烯损失量以及操作回流比随当地风级变化的实际情况，形象地说明了风载荷对高塔分离效率的影响，并在新的设计方案中，对安装方式采取了措施，增强了塔的刚度，从而提高塔板效率１３％左右，而且有明显的节能效果。     

浅述流体力学因素对精馏塔塔板效率的影响

塔板效率在实际塔设备设计中作为一个极为重要的指标,不仅描述了塔板上的传质效果,而且也是传统平衡级理论中连接工艺变量(理论板数)与设备变量(实际塔板数)的桥梁。从气液构型、液相返混、气液不均匀分布、塔板上气体混合、漏液、雾沫夹带等方面详细剖析了影响塔板效率的各个因素,以期为各种塔板的最佳操作点提供理论依据。     

精馏塔板数的算图法

本文根据精馏塔计算的几个简化经验式,绘制成算图。能适用于二元物系和清晰分割情况的多元物系的精馏塔计算;可供精馏塔的粗略估算和精确计算时选择初值时用。     

筛板精馏塔的板效率研究

在直径为0.75 m,塔高4m的不锈钢热模塔内,以正庚烷—环己烷为物系、在常压、全回流条件下,进行筛板塔传质效率的研究,选取孔径为13mm和6 mm,开孔率为3.9％和6.4％的塔板,测试了这些塔板的气液相默弗里板效率,通过排列组合,考察了孔径、不同塔板位置和出口堰高对传质效率的影响,并进行了传质效果对比.此外还运用A...     

悬挂降液管塔板的冲击漏液及其对传质效率的影响

从理论上分析了悬挂式降液管塔板上产生冲击漏液的原因，并提出在塔板的受液区安装防冲漏液装置来减小冲击漏液量。在－φ500的冷模塔内以空气－水为物系测定了冲击漏液量，在－φ300的热模内以酒精－水为特系测定了塔板效率。结果表明：没装防冲击漏液装置的悬挂工降液管塔板的冲击漏液量达总液量的7％以上，而安装防冲击漏液装置的悬挂式降液管塔塔板基本上没有冲击漏液，可以提高塔板传质效率5％以上。     

双组分精馏塔塔盘层数的设计计算

本文使用计算机进行双组分精馏塔塔板数的计算,分别采用McCabe-Thiele法及焓浓度法进行理论板层数的计算,计算表明,两种方法结果相近,McCabe-Thiele法更为广泛应用。     

The Mai-distribution of Weeping from a Distillation Tray and Its Effect on Tray Efficiency

Experiments demonstrated that the weeping is mal-distributed and occurs mainly in a region of tray deck next to the inlet weir. The amount of weeping in this region depends on the weeping rate. On this basis, three types of weeping distribution are proposed. The effect of mal-distributed weeping on the Murphree tray efficiency is evaluated by using the three-dimensional non-equilibrium mixing pool model, where the influences of the flow pattern and the variation of Murphree point efficiency on a tray are taken into account. The calculated results reveal that the extent of Murphree tray efficiency drop depends chiefly on the degree of mal-distribution and the percentage of weeping. It is also demonstrated that in the determination of the lowest operating limit of vapor velocity, the unfavorable effect of mal-distributed weeping should be considered as an important factor and cannot be ignored.     

气相夹带对蒸馏塔板效率的影响

本文给出了在完全泡沫状态或以泡沫为主的混合状态下进行蒸馏操作时包括气相夹带的板效率模型,导出了Lewis的第一、第二和第三种情况的板效率计算式,讨论了气相夹带对板效率的影响,并与FRI的实验值作了比较.     

雾沫夹带对蒸馏塔板效率的影响

在塔板上液体完全混合的条件下,雾沫夹带对蒸馏塔板效率的影响,导出了一个新的关系式.著名的Colburn关系式是本文关系式的一种特殊情况(λ_o=1).计算结果表明,用于校正雾沫夹带对塔板效率的影响,本文关系式与Colburn关系式相比,具有较小的误差.     

汽—液—液三相与汽—液两相塔板效率比较

本文通过小型精馏塔及600×150 mm~2矩形模拟塔的实验,对比研究了气(汽)-液两相和气(汽)-液-液三相的塔板效率。并就物系性质(表面张力梯度、液体粘度或分散粘度),两液相体积比,气速及操作工况对传质的影响进行了研究。提出三相传质和两相传质差异的主要因素,得出估算三相精馏塔板效率的关联式。     

筛板不均匀漏液的规律及其影响

筛板不均匀漏液的规律及其影响曾爱武刘富善许松林黄洁余国琮（天津大学化学工程研究所，天津３０００７２）关键词筛板不均匀漏液塔板效率１引言塔板漏液是一种导致塔板效率降低的纵向返混。在工程设计中通常以相对漏液１～１０％来决定气相负荷下限，但值得指出的...     

汽体混合对塔板效率的影响

在液体部分混合条件下,为考虑汽体混合对塔板效率的影响,本文提出了一个新的混合模型,并获得了计算塔板效率的数学关系式.经与其它模型的计算结果比较,相当吻合.而计算方法大为简化.     

利用计算流体力学及计算传质的方法研究精馏塔传质效率

It has long been found that the flow pattern of the liquid phase on distillation tray is of great importance on distillation process performance. But until now, there was very few published work on quantitative investigation of this subject. By combining the computational fluid dynamics (CFD) with the mass transfer equation, a theoretical model is proposed for predicting the details of velocity and concentration distributions as well as the tray efficiency of distillation tray column. Using the proposed model, four different cases corresponding to different assumptions of liquid and vapor flowing condition for a distillation tray column were investigated. In Case I, the distributions of velocity and concentration of the incoming liquid from the downcomer and the uprising vapor from the underneath tray spacing are uniform. In Case Ⅱ, the distribution of the incoming liquid is non-uniform but the uprising vapor is uniform. In Case Ⅲ, the distribution of the incoming liquid is uniform but the uprising vapor is non-uniform.In Case IV, the distributions of both the incoming liquid and the uprising vapor are non-uniform. The details of velocity and concentration distributions on a multiple sieve tray distillation column in four different cases were simulated using the proposed model. It is found that the shape of the simulated concentration profiles of vapor and the liquid is quite different from case to case. The computed results also show that the tray efficiency is highly reduced by the maldistribution of velocity and concentration of the incoming liquid and uprising vapor. The tray efficiency for Case Ⅰ is higher than Case Ⅱ or Case Ⅲ, and that for Case Ⅳis the lowest. It also reveals that the accumulated effect of maldistribution becomes more pronounced when the number of column trays increased. The present study demonstrates that the use of computational method to predict the mass transfer efficiency for the tray column, especially for the large one, is feasible.