固旋阀塔板的性能研究

在内径为600 mm的不锈钢塔内,以空气-水-氧气为物系,对固旋阀塔板的流体力学和传质性能进行研究。测定了塔板传质效率和雾沫夹带量,并与F1浮阀塔板进行对比;通过计算流体力学软件Fluent对固旋阀塔板上气相三维流场进行了数值模拟。实验结果表明:当液相喷淋密度L=5 m~3/(m~2·h)时,随着气体负荷的逐渐增大,固旋阀塔板的传质效率从小于F1浮阀到逐渐接近F1浮阀,且在实验最大气体负荷条件下超过了F1浮阀;当液相喷淋密度较大时,固旋阀塔板的传质效率高于F1浮阀塔板,且随着气体负荷的增大,差异越来越明显;固旋阀塔板的雾沫夹带比F1浮阀塔板低50%—60%,因此具有更高的气相负荷操作上限。Fluent软件模拟结果表明,固旋阀塔板中旋转流场的存在促使液层分布更均匀,气液传质得到进一步强化。     

新型导向筛板-浮片式浮阀复合塔板的研究

设计了一种新型导向筛板-浮片式浮阀复合塔板。在直径为1. 2 m的圆形有机玻璃塔中进行冷模实验,测定了实验塔板在不同条件下的性能参数。实验表明,当液流强度一定、阀孔动能因子升高时,塔板压降、雾沫夹带量和传质效率增大,而漏液量会减小;当阀孔动能因子一定、液流强度升高时,塔板压降、雾沫夹带量和漏液量均会增大,但传质效率会减小。此外,对F1浮阀塔板和ADV浮阀塔板在相同实验条件下进行冷模实验,结果表明,新型导向筛板-浮片式浮阀复合塔板的流体力学性能更好。     

导向浮阀型塔板的性能和工业应用

介绍了导向浮阀型塔板的结构特点、操作性能、设计方法和工业应用情况.实验研究和工业应用情况表明,导向浮阀型塔板为国内最佳的浮阀型塔板.     

复合条形细分浮阀流体力学性能研究

采用空气-水系统在1200 mm的冷模塔内对一种新型浮阀塔板———复合条形细分浮阀(CRSV)的流体力学性能进行了实验研究。测定了塔板压降、塔板泄漏、塔板雾沫夹带等性能,并且在相同的实验条件下与标准的F1型浮阀进行了对比实验。实验结果表明:复合条形细分浮阀塔板比标准的F1型浮阀塔板压降可低10%—20%,雾沫夹带量低20%,低气速下泄漏量低15%—30%,这表明复合条形细分浮阀具有更好的操作弹性。     

浮阀鼓泡器塔板的流体力学性能实验

分析了浮阀鼓泡器的结构特点。在1000mm×350mm规格的实验塔中,应用典型的水—空气冷模实验系统对浮阀鼓泡器塔盘进行了实验研究,测定了多种气液负荷下的塔板压降、雾沫夹带和泄漏量等流体力学性能。利用氧解吸法测定了塔板传质效率,并与F1型浮阀塔板进行了对比研究。实验结果表明,在相同条件下,浮阀鼓泡器塔板比F1型浮阀塔板的板效率提高10%～20%,板压降降低200Pa以上,雾沫夹带与泄漏与F1阀基本相当。在小气速时,由于浮阀鼓泡器存在着鼓泡口而使得泄漏量比F1阀稍大,不过在工业应用范围内,浮阀鼓泡器的泄漏量和F1浮阀基本相当。是一种综合性能优良的新型浮阀。     

倾斜塔板漏液的三维数值模拟及实验

塔体受到横向载荷作用,板式塔的塔板倾斜,塔板上液层出现非等高。在冷模试验塔装置中以空气-水为实验介质,对倾斜塔板的漏液性能进行了实验研究。实验表明,塔板倾斜方向与液相流动方向相同时,倾斜塔板漏液小于水平塔板,倾角越大漏液越少,塔板气相操作下限减小;塔板倾斜方向与液相流动方向相反时,倾斜塔板漏液大于水平塔板,倾角越大漏液越多,塔板气相操作下限增大。利用计算流体力学的双欧拉模型对倾斜塔板的漏液状态进行了三维数值模拟,模拟结果同实验结果吻合较好。模拟结果显示,倾斜塔板在液层非等高剖面上发生不均匀漏液,倾角大的塔板在液层薄的区域发生气相沟流现象。     

导向孔与筛孔和导向浮阀复合塔板的实验研究

设计了导向孔-导向浮阀复合塔板和筛孔-导向浮阀复合塔板,在板间距为600 mm,液流强度为20 m~3/(m·h),1 500 mm×450 mm的矩形塔内,以空气-水系统测试了3种塔板的干板压降,湿板压降,雾沫夹带率,漏液率,清液层高度,泡沫层高度水力学性能。由实验数据分别拟合了3种塔板干板压降,湿板压降,雾沫夹带率,漏液率的关联公式。实验表明:筛孔-导向浮阀复合塔板在压降和漏液率方面优于导向浮阀塔板;导向孔-导向浮阀复合塔板在水力学方面都优于导向浮阀塔板,是一种操作弹性大,具有更好水力学性能的优良塔板;选择合适的塔内件复合也是改善塔板性能的关键。     

3D窄条阀性能研究

详细分析了实用新型专利3D窄条阀塔盘的结构特点、实验研究和工业应用情况。在1000 mm×350 mm规格的试验塔中,以空气和水为工质进行了冷模实验,测定了多种气液负荷下3D窄条阀的总板压降、雾沫夹带、泄漏量等流体力学性能,利用氧解吸法标定其塔板传质效率,并在相同条件下与F1浮阀进行了对比试验。试验结果和工业应用表明,3D窄条阀的塔板效率远高于传统的F1浮阀,且峰值范围宽广,压降低,在操作弹性范围内泄漏量趋于0,只是在泄漏点以下其泄漏量比F1浮阀稍高,是一种综合性能优良的新型浮阀。     

组合导向浮阀塔板的CFD模拟及反向流分析

精馏塔板上的气液两相流动对传质效率有重要影响。根据实验数据拟合得到平均气含率关联式,将其加入动量源项,采用Fluent软件对1.2 m直径的组合导向浮阀塔板上的气液两相流动进行CFD模拟,考察了塔板上的气液两相流动状况。清液层高度的模拟结果与实验数据关联式相吻合,验证了模拟的正确性。对塔板上液相的非理想流动进行了分析,通过对反向流进行量化和统计计算出反向流体积分数(即反向流体积占塔板总体积的百分比)。3块不同浮阀排布塔板的反向流体积分数时均值的计算结果表明,梯形浮阀和矩形浮阀的排布方式对反向流影响很大,通过合理排布能够使工业塔板的反向流体积分数时均值从22.0%下降到19.4%,降幅达到11.8%。本研究结果可望对塔板的设计和优化提供指导。     

组合导向浮阀塔板的CFD模拟及反向流分析

精馏塔板上的气液两相流动对传质效率有重要影响。根据实验数据拟合得到平均气含率关联式,将其加入动量源项,采用Fluent软件对1.2 m直径的组合导向浮阀塔板上的气液两相流动进行CFD模拟,考察了塔板上的气液两相流动状况。清液层高度的模拟结果与实验数据关联式相吻合,验证了模拟的正确性。对塔板上液相的非理想流动进行了分析,通过对反向流进行量化和统计计算出反向流体积分数(即反向流体积占塔板总体积的百分比)。3块不同浮阀排布塔板的反向流体积分数时均值的计算结果表明,梯形浮阀和矩形浮阀的排布方式对反向流影响很大,通过合理排布能够使工业塔板的反向流体积分数时均值从22.0%下降到19.4%,降幅达到11.8%。本研究结果可望对塔板的设计和优化提供指导。     

浮阀塔板最新应用研究进展

浮阀塔是一种应用极为广泛的汽液传质设备,本文介绍了国内研究开发的新型浮阀塔板。这些浮阀塔板是在F1型浮阀塔板的基础上开发而成的,相比于F1型浮阀塔板,具有压降低、雾沫夹带量小、泄漏量小、处理量大等优点。本文以塔板的开发年代和塔板类型为主线,对这些浮阀塔板的结构特点、流体力学、传质性能、优缺点等进行了概括总结,对每个系列浮阀塔板的设计开发理念进行了总结概括,同时介绍了导向浮阀塔板在齐鲁石化公司丁二烯装置中应用的成功实例,很大程度地提高了塔板负荷率和产品质量;并简单介绍了一些常用塔板在工业生产中的应用情况,阐述了这些新型浮阀塔板的发展思路,即浮阀形状以条形为主,并且大部分浮阀塔板都开有导向孔;最后指出了今后塔板技术的研究和发展动向。     

半椭圆固定阀塔板性能研究

应用空气–富氧水系统,在直径1 200 mm不锈钢塔内,对半椭圆固定阀塔板进行了实验室研究,研究结果表明:半椭圆固定阀塔板的压降略高于筛孔塔板,比F1浮阀塔板小得多,雾沫夹带率低于筛孔塔板和F1浮阀塔板,泄漏率比筛孔塔板低,比F1浮阀塔板高,传质效率优于筛孔塔板和F1浮阀塔板,是一种综合性能优异的塔板。     

Predicting valve tray efficiency

Existing literature models for predicting the mass transfer efficiencies of binary hydrocarbon, distillation columns employing moving valve trays are evaluated. Only four models for predicting valve tray efficiencies exist in the open literature. All of these models use data from valve trays. The last theoretical model was published in 1972, 42 years ago. By comparison, sieve tray efficiency models are numerous and recent. Sieve tray models were developed from large databases. There are no valve tray equivalents to the fundamental mechanistic models available for sieve trays. Despite the differences between valve and sieve trays, many of the phenomena on sieve and valve trays are similar. Consequently, sieve tray models can be employed to provide estimates for valve trays. In this work, using public FRI data on round moving valves, the performance of the Chen and Chuang sieve tray mechanistic model is compared to the performance of four valve tray models. It appears that, in the absence of fundamental (and qualified) valve tray models, the sieve tray models present a potential alternative for valve tray efficiency predictions.     

Overall efficiency evaluation of commercial distillation columns with valve and dualflow trays

The main objective of this work is to establish appropriated ways for estimating the overall efficiencies of industrial distillation columns with valve trays with downcomer and dualflow trays. The knowledge of efficiencies has fundamental importance in the design and performance evaluation of distillation columns. Searching in the literature, a tree of alternatives was identified to compose the tray efficiency model, depending on the mass transfer models, the liquid distribution and vapor flow models on the tray, the liquid entrainment model, the multicomponent mixture equilibrium model, the physical properties models, the height of froth on the tray model and the efficiency definition. In this work, different methods to predict the overall efficiency of distillation columns with valve and dualflow trays were composed and compared with data from three commercial distillation columns under different operating conditions. The models were inserted in the Aspen Plus 12.1 simulator, in Fortran language, together with tray geometrical data, fluid properties and operating data of the distillation columns. For each column, the best thermodynamic package was chosen by checking the temperature profile and overhead and bottom compositions obtained via simulation against the corresponding actual data of industrial columns. A modification in the fraction of holes evaluation that is jetting parameter of the Garcia's hydraulic model of dispersion above the tray was proposed. This modification produced better results than the original model to predict the fraction of holes that are jetting and in the efficiency of dualflow trays and similar results to Garcia model in the efficiency evaluation of valve trays. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

导向浮阀塔板在醋酸生产中的应用

导向浮阀塔板是在F1型浮阀塔板的基础上开发成功的，较早应用于炼油装置的常减压蒸馏塔，在提高轻油的收率上获得了较大的经济效益，在化工产品的分离中应用较少。该项目在醋酸装置的精馏工序中，采用先进的导向浮阀塔板改造原有的F1型浮阀塔板，达到节能降耗，提高醋酸收率，增加醋酸产量，提高经济效益的目的。     

新型浮阀塔板研究进展

介绍了在传统圆盘形浮阀、条形浮阀及固定阀塔板基础上研究开发的新型浮阀塔板。分析了各种新型浮阀塔板的结构特点、流体力学性能和传质性能,并比较了各种新型浮阀塔板的优缺点,概述了在不同生产工况下浮阀塔板的选择。     

Trays for gas-liquid contacting

A type of tray for gas-liquid contacting is described, in which the free area for gas flow through the tray is variable with and controlled by the gas flowrate. The property through which control of the free area is effected is the surface tension of the liquid phase. The advantages are the same as those of ballast and valve trays; namely, reduced pressure drop at high gas rates resulting in increased column capacity, and reduced free space at lower gas rates resulting in high mass transfer efficiency at low and medium vapor loadings as well. Tooling and production costs for the trays of the present investigation, however, are considerably lower than for ballast or valve trays or any other types which require machining operations in their fabrication, and are as low or lower than for sieve trays. Initial experimental comparisons with conventional trays demonstrated that the trays of the present investigation, although designed primarily for operation at high vapor loadings, were indeed capable of yielding high mass transfer efficiencies in the low-to-medium range of vapor loading     

B型导向浮阀塔板实验研究

为增大导向浮阀塔板对液体流动的推动力,在1600 mm×400 mm实验塔内,利用空气-水系统,对B型导向浮阀塔板进行实验研究。与导向浮阀塔板相比,它具有更好的流体力学性能和更大的液体负荷适用范围。实验研究和工业应用表明,B型导向浮阀塔板具有处理能力约提高20%、塔板效率约提高10%、操作弹性约提高30%等突出特点,用于蒸馏、吸收、汽提等传质过程,可获得良好效果。     

导向浮阀塔板的实验研究和工业应用

介绍了导向浮阀塔板的结构特点、实验研究和工业应用情况。由于导向浮阀塔板上的液面梯度较小,液体返混较小,并可消除塔板上的液体滞止区,因而具有优秀的操作性能。导向浮阀塔板已在近百个塔内工业应用,均获得显著的经济效益。     

Hydraulic,mass transfer and heat transfer performance comparison between ordered bed packing and sieve trays

The Girdler–Sulfide (GS) heavy water production process has traditionally used tray columns because of their large size. In recent years, the chemical industry has extended the use of packing to larger columns because of economic and performance advantages. A pilot scale study was thus initiated to compare the hydraulic, mass transfer and heat transfer performance of an ordered bed packing (Mellapak) with sieve trays operating under GS process conditions. Mellapak offered lower pressure drops, higher throughputs and improved heat transfer over sieve trays. However, benefits to deuterium mass transfer were only marginal in large diameter columns.