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浮阀塔板最新应用研究进展 总被引:1,自引:0,他引:1
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。 相似文献
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The Dualflex tray is a fractionation device without downcomers but with mobile valve plates and top weirs positioned above the perforations of the tray deck, which allows liquid and vapor or gas to pass through. According to the results of systematic experimental investigations, this mass transfer device can be considered as a high capacity tray in comparison with conventional trays; its separation efficiency is also higher than that of a comparable Dualflow tray under identical test conditions. It can be recommended not only for installing in new separation plants, but also for revamps in cases where increasing throughput in existing columns are required. The aforementioned efficiency and capacity studies were carried out in a pilot plant of 600 mm column diameter. 相似文献
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The novel SiC foam valve tray was made of thin slices of SiC foam material with a high specific surface area. Hydrodynamic performances of the novel SiC foam valve tray were studied with air-water system at atmospheric pressure. These performance parameters included pressure drop, entrainment, weeping and clear liquid height. The mass transfer efficiency of the SiC foam valve tray was measured in laboratory plate column. Compared with the F1 float valve tray, the dry pressure drop was decreased about 25%, the entrainment rate was about 70% lower at high gas load, the weeping was much better, and the mass transfer efficiency was far higher. Thus, the overall performance of the novel SiC foam valve tray was better than that of F1 float valve tray. 相似文献
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Anand N. Vennavelli James R. Whiteley Michael R. Resetarits 《Chemical Engineering Research and Design》2014
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. 相似文献
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The mean relative gas hold up εa , and the volumetric mass transfer coefficients, kLa, were measured by steady state method in a six stage countercurrent bubble column 20 cm in diameter and 381 cm high. Perforated plate trays 0.5, 1.0 and/or 3.0 mm in bore hole diameter were applied. The height of the stages were varied from 10 to 50 cm. Distilled water, salt-, methanol-, ethanol-, η -propanol-, glucose-solutions and the combination of salt and alcohol and glucose solutions were used as media.The trays with the smallest bore hole diameter and free cross sectional area are the most efficient with regard to kLa. With small bore hole diameter and free cross sectiord area of the tray as well as with coalescence suppressing media the optimal stage height is large, with large hole diameter and free cross sectional area of the tray as well as with coalescence promoting media the optimal stage height is small. 相似文献
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Reinhard Billet 《化学工程与技术》1997,20(4):221-229
To review mass transfer trays from a process point of view, the dependence of efficiency on the loadings, the loading range and the maximum loadings with an acceptable tray efficiency have to be known. Comparing the results taken from experiments on Dualflex trays and from other types of trays which have been in industrial applications for many years and which are recognized as “industrial standard”, has been evaluated in this review. 相似文献
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A new numerical procedure to minimize the entropy production in diabatic tray distillation columns has been developed. The method was based on a least square regression of the entropy production at each tray. A diabatic column is a column with heat exchangers on all trays. The method was demonstrated on a distillation column separating propylene from propane. The entropy production included contributions from the heat transfer in the heat exchangers and the mass and heat transfer between liquid and vapor inside the distillation column. It was minimized for a number of binary tray distillation columns with fixed heat transfer area, number of trays, and feed stream temperature and composition. For the first time, the areas of heat exchange were used as variables in the optimization. An analytical result is that the entropy production due to heat transfer is proportional to the area of each heat exchanger in the optimal state. For many distillation columns, this is equivalent to a constant driving force for heat transfer. The entropy production was reduced with up to 30% in the cases with large heat transfer area and many trays. In large process facilities, this reduction would ideally lead to 1-2 GWh of saved exergy per year. The most important variable in obtaining these reductions is the total heat transfer area. The investigation was done with a perspective to later include the column as a part in an optimization of a larger process. We found that the entropy production of the column behaved almost as a quadratic function when the composition of the feed stream changed. This means that the feed composition is a natural, easy variable for a second law optimization when the distillation column is a part of a process. The entropy production was insensitive to variations in the feed temperature. 相似文献
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新型立体传质塔板(CTST)结构新颖, 充分利用塔板空间进行传质,具有通量大、效率高、压降低、抗堵性能强、消泡性能好等优点.在工业规模的实验塔上对立体传质塔板的塔板压降、帽罩底隙处罩内外压强、帽罩内部气相速度分布规律、雾沫夹带量、气体对液体的提升能力、塔板空间持液量等几个方面的流体力学性能进行了研究.结果表明,立体传质塔板克服了穿过塔板液层的阻力,板压降较低;塔板上帽罩底部的进液口处,罩内压强低于罩外,利于吸液;罩内气相速度分布比较合理;气液两相负荷均可较大幅度提高,而且雾沫夹带量非常低;气体对液体的提升性能以及塔板空间的持液性能都比较理想. 相似文献
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就痕量精馏中塔板传质效率低、需强化气液传质的问题,研究者提出了新型鼓泡破泡一体化高效精馏塔盘,通过在筛板上泡沫层高度范围内设置一层破泡装置,打破大气泡,减小气泡体积,强制界面进行更新,从而提高传质效率。采用双欧拉模型分别对鼓泡破泡一体化塔盘和筛板进行了气液流场的数值模拟,并对模型进行了验证。对比两种塔板的计算结果可以看出:在相同操作条件下,破泡装置将大气泡破裂成无数小气泡,使高气含率区域面积较普通筛板进一步增大,且气含率梯度变化更均匀;增加破泡装置后,在相同气速条件下气泡上升速度下降,气体在液层中的滞留时间延长,使鼓泡层高度增加,可显著提高传质效率,且降低了气体雾沫夹带量;破泡装置还明显改善了气相的纵向分布,气含率由塔板底部向上逐渐增大且存在明显分界;破泡装置附近湍动较剧烈,气泡破碎喷出的气体会进一步撕裂液膜,气体破碎作用会抑制气泡聚并,促进界面的快速更新更有利于传质过程的进行。研究结果可对工业塔板设计和优化提供指导。 相似文献
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T. L. Domingues A. R. Secchi T. F. Mendes 《American Institute of Chemical Engineers》2010,56(9):2323-2330
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 相似文献
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Understanding 3 pass trays is the key to design of 6 pass trays, such as those in the large towers expected in carbon-capture services. This paper presents a hydraulic distribution model for 3 pass trays with no liquid or vapor equalization. The model is verified by comparison with FRI's test data and with one operating tower. Our paper predicts good distribution for the 3 pass trays tested at FRI, and shows that the poor efficiencies in some of the tests were due to losing the downcomer seals and not tray maldistribution. The model predicts good distribution at maximum rates in the operating tower, but finds that at lower rates, where valves open and close, there is an extreme sensitivity of vapor distribution to small pressure drop variations. This sensitivity precludes reliable modeling of distribution in this region and may define an unstable region in the operation of 3 pass trays. 相似文献