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汽液液三相精馏总板效率的研究 总被引:7,自引:2,他引:5
在Oldershaw精馏塔内,对汽液液三相精馏筛型塔板上的传质特性进行测试,研究了泡沫工况下,汽速、液汽比等操作条件,表面张力梯度、界面张力、乳化液分散粘度等物系性质,以及油水体积比等多种参数对总板效率的影响、对测试数据进行关联,获得了适用于泡沫工况下汽液液三相精馏过程的总板效率估算式,此关联式对设备设计及操作优化有一定的参考价值. 相似文献
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汽液液三相精馏全塔效率模型及分析 总被引:4,自引:0,他引:4
在探讨汽液两相精馏塔板效率模型及影响因素的基础上,在Oldershaw精馏塔内,对影响汽液液三相 精馏全塔效率的各种因素进行了深入研究,建立了基于泡沫工况下的汽液液三相精馏全塔效率模型,通过对实 测数据的关联,获得了上述模型参数。 相似文献
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以空气-水-玻璃微珠和空气-石蜡油-玻璃微珠两种三相系统为研究对象,在常温常压下分别考察了液体介质的粘度等物性因素,表观气速、固含率、液体循环量等操作因素,气体分布器、分隔板等结构因素对循环浆态床反应器气液传质特性的影响.实验结果表明,气液传质系数随表观气速的增加而增加,随液体粘度和固含率的增大而减小,当表观气速和固含率增加到一定程度后,传质系数趋于稳定;低气速下,玻璃烧结板的传质效果较好,而较高气速时,多孔板和新型锐孔分布器的传质效果较好;分隔板能显著增大气液传质系数.对多孔板分布器实验数据进行了拟合,得出气液传质系数的经验关联式,关联式计算值与实验结果吻合良好. 相似文献
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以空气-水-黄沙以及空气-液体石蜡-黄沙两种系统为对象,在常压下用溶氧仪研究了采用小孔式及金属烧结板两种分布器的高固含率三相淤浆反应器的气液传质特性,以及固含率和表观气速等因素对容积气液传质系数kLa的影响,最后得到采用上述两种气体分布器的高固含率三相淤浆床关于容积气-液传质系数的经验关联式。实验证明,金属烧结板具有更好的气液传质特性。 相似文献
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本文根据汽-液两相的反应和传质、传热特征,结合两相界面的平衡性质建立了描述反应精馏过程实际板的反应-扩散(非平衡级)模型。从而避免了板效率取值问题和由此带来的计算不确定性。模型方程由汽-液两相质量衡算方程、焓衡算方程、汽-液相界面平衡关系式和组分浓度归一化方程等基础方程以及诸如有关的求算相间传质通量的特征方程组成。利用所提出的两组方程对汽-液两相反应精馏过程的实际板进行了模拟计算。 相似文献
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Sieve tray efficiencies for the distillation of methanol/water, acetic acid/water and cyclohexane/n-heptane mixtures were measured as a function of composition under fixed vapour and liquid rates in a 0.15 m diameter distillation column. Experimental results show that surface tension has a significant effect on tray efficiency and the number of transfer units. Further tests in a simulator column with air/water, air/methanol and air/(water + surfactant) systems having different surface tensions revealed that bubble sizes in froths are mainly determined by surface tension. The results also show that bubble break-up and coalescence occurs in the froths. 相似文献
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The droplet size distribution with large-holed compound sieve tray operating in the spray regime is measured by using a double electrical probes technique in a cold model column of 400 mm diameter. The results indicate that the hole F-factor Fo and surface tension are the main factors which influence the liquid dispersion expressed by the Sauter mean diameter D32. A correlation of D32 on surface tension, viscosity, F-factor, weir height and liquid flow rate is proposed. 相似文献
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The mass transfer efficiencies of dualflow trays with open hole areas of 20, 28 and 37% were experimentally investigated under total reflux conditions in a 300-mm diameter distillation column using methanol-water and methanol-isopropanol systems. The results indicate that the efficiency of a dualflow tray is a strong function of the open hole area, the vapor/liquid load, and liquid properties such as surface tension and density. A fundamental model was developed to predict tray efficiency. The prediction was found to agree with the measured data to within 15.3%. 相似文献
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The main feature of a distillation process is its efficiency. The gas‐liquid bubbling layer formed on the trays and the ongoing mass‐exchange process during distillation is influenced by the change of the surface tension gradient during this mass‐exchange procedure. Binary mixtures with respect to the change of the surface tension effect can be divided into positive, negative, and neutral ones. In order to assess the effect of surface tension on mass transfer, the stabilization index quantity is applied, representing the product of the liquid phase process momentum and the surface tension gradient in the mixture of the liquid phase. One possibility to express the Marangoni efficiency enhancement ratio by experimental distillation data obtained under identical hydrodynamic conditions in two binary systems, i.e., a positive (methanol‐water) and a neutral one (methanol‐ethanol), is presented. 相似文献
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1 INTRODUCTION Magnetically stabilized beds (MSB) have at- tracted many research interests, owing to the unique feature of combination of characteristics for packed bed and conventional fluidized bed, especially in the field of biotechnology processes such as bioseparation or immobilized enzyme catalyzed systems. However, there are few reports about the effects of physical properties of fluids on the axial liquid dispersion coef- ficients in both L-S and G-L-S MSB. Siegell[1] , Goetz … 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