十字旋阀塔板漏液性能

在φ1000mm的圆塔内,以空气-水为介质,对十字旋阀塔板的泄漏率进行了测试,考察了液流强度、出口堰高等因素对泄漏性能的影响,并将其与交错十字旋阀塔板、组合导向浮阀塔板和F1型浮阀塔板的泄漏率进行了对比。结果表明:十字旋阀塔板在气速超过临界阀孔气速且液流强度较小时具有很好的漏液性能,经数据关联,获得了十字旋阀塔板漏液点孔速的关联式。     

部分回流下波纹导向浮阀塔板板效率的研究

以环己烷-正庚烷为物系,采用直径750 mm、塔高4000 mm、内置4块塔板的热模塔,在常压、部分回流操作条件下,研究了开孔率、回流比和阀孔动能因子对波纹导向浮阀塔板效率的影响;同时将其全塔效率与F1型浮阀塔板和组合导向浮阀塔板的全塔效率进行了比较。此外,还将其实验值与Chen,Chuang模型,Chan,Fair模型预测的效率值作比较,并进行了实验误差分析。实验结果表明:在相同操作条件下,开孔率小,塔板效率高;相同开孔率下,回流比降低,传质性能下降。堰高为30 mm时,波纹导向浮阀塔板的全塔效率比F1型浮阀塔板和组合导向浮阀塔板高近10%。Chen,Chuang模型值与实验值相近,可用它来预测该塔板的板效率。     

新型浮阀塔板的流体力学性能

在φ1 000 mm的圆塔内,采用空气－水系统,对十字旋阀塔板、组合导向浮阀塔板、ADV浮阀塔板和F1浮阀塔板的阀孔临界气速和压降进行了对比试验。此外,还对前3种浮阀塔板的泄漏和雾沫夹带进行了对比试验。实验数据由计算机实时采集和处理,试验结果综合表明：十字旋阀塔板适用于低液流强度操作状况;组合导向浮阀塔板适用于大液流强度的操作状况;ADV浮阀塔板则适用于中等液流强度操作状况。     

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。     

波纹导向浮阀塔板的传质性能

以环己烷-正庚烷为物系,在直径750 mm、高4000 mm、装有4层塔板的不锈钢圆塔内对波纹导向浮阀塔板和F1浮阀塔板进行了传质性能的测试。在常压全回流条件下,考察了阀孔动能因子对传质效率的影响。结果表明:在实验范围内,随着阀孔动能因子的增大板效率会有不同程度的增大,波纹导向浮阀塔板的板效率和全塔效率均比F1型浮阀塔板高。     

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。     

新型固定阀塔板的流体力学和传质性能研究

提供了一种阀盖两侧具有向下弯曲折边的新型固定阀。在内径为500mm的有机玻璃塔内,以空气水为物系,研究了其流体力学性能;在内径为300mm的不锈钢塔内,以乙醇水为物系,常压全回流情况下,研究了其传质性能。研究结果表明:新型固定阀塔板的板压降略高于筛孔塔板,比F1 浮阀塔板小得多,雾沫夹带量小,雾沫夹带液泛点阀(筛)孔动能因子均比筛孔塔板、F1 浮阀塔板大,漏液量较小,漏液点阀(筛)孔动能因子比筛孔塔板低,比F1 浮阀塔板高,传质效率与F1 浮阀塔板相当。     

新型高效3D圆阀塔板的实验研究

详细分析了新型高效3D圆阀的设计原理和特点. 在1000 mm′350 mm规格的矩形实验塔中,应用典型的水-空气冷模实验系统对3D圆阀和F1型浮阀两种塔盘进行了对比实验研究,测定了多种气液负荷下两种圆形浮阀塔板的板压降、雾沫夹带和漏液量等流体力学性能. 利用氧解吸法测定了两种浮阀塔板的传质效率. 实验结果表明,在相同条件下,3D圆阀塔板的板效率比F1型浮阀塔板提高约20%左右,雾沫夹带量比F1型浮阀塔板略小,在工业应用范围内,3D圆阀的板压降和漏液量均比F1型浮阀小,是一种综合性能优良的新型圆阀.     

组合导向浮阀塔板的板效率研究

在直径为0.75 m的不锈钢塔内,以正庚烷-环己烷为物系,常压全回流条件下,进行了组合导向浮阀传质效率的研究,测试了该塔板的气、液相默弗里板效率和全塔效率,并和F1型浮阀塔板的全塔效率进行了对比。采用AIChE与Chen,Chuang 2种传质模型计算了组合导向浮阀塔板的点效率值。研究了AIChE与Molnar 2种计算涡流扩散系数的方法对默弗里板效率的影响。实验结果表明:在正常操作范围内组合导向浮阀塔板全塔效率高于F1型浮阀塔板。经比较实验值与模型值,发现采用Chen,Chuang预测点效率和Molnar方法计算涡流扩散系数所估计的默弗里板效率偏差在11%内。     

不同轻重比例的十字旋阀塔板压降的实验研究

在直径为1 000 mm、板间距600 mm、内置4块塔板的不锈钢圆塔中,以空气-水为介质,对十字旋阀塔板的压降进行了实验研究。在相同开孔率15.52%下,考察了3个液流强度和3个堰高条件下,对不同轻重比例(100%,86%,70%,50%,0)十字旋阀塔板压降的影响。结果表明:相同液流强度和堰高条件下,不同轻重比例塔板压降的关系是050%70%86%100%;相同轻重比例和堰高条件下,液流强度越大,塔板压降越大;相同轻重比例和液流强度条件下,堰高越大,塔板压降越大;这3种因素导致的塔板压降差异均随着阀孔动能因子F0的增大而逐渐缩小。     

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...     

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。     

浮阀脱落对塔板操作性能的影响

通过理论和实验分析,讨论了浮阀脱落对塔板操作性能的影响。塔板上部分浮阀脱落时,气相通过浮阀脱落后形成的大筛孔中的速度约为正常阀孔中速度的2.5—6倍,这种气相在塔板上分布不均的现象会对塔板的流体力学性能和传质性能产生较大影响。实验结果表明,随着浮阀脱落比例的增大,塔板压降减小,泄漏量、雾沫夹带量增大,使塔板的操作弹性下降,当液相负荷较小时将会导致塔板效率显著降低。     

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。     

Theoretical and experimental investigation on the characteristics of fly‐ash scrubbing in a fixed valve tray column

The goal of this study is to evaluate the performance of a fixed valve tray column designed to remove fly‐ash particles. A series of experiments were carried out at room temperature to demonstrate the collection efficiency of a fixed valve tray column at different gas and liquid superficial velocities. The fly‐ash particles removal characteristics of the fixed valve tray column were evaluated by measuring variations of concentration and size distribution of particles in the outlet. The mechanism of particle removal in this turbulent dispersion system was theoretically analyzed on the basis of diffusion, interception, sedimentation and impaction, and a model was proposed to predict the collection efficiency. The results show that the simulation results agree well with the experimental data. In contrast to most of the conventional models, the present model is capable of evaluating the effects of bubble hydrodynamics, system property, and operation conditions on the collection efficiency. The model is expected to guide effectively the design and operation of valve tray washing columns, which is widely applied nowadays. © 2012 American Institute of Chemical Engineers AIChE J, 59: 2168–2178, 2013     

Effect of two-pass trays on distillation efficiencies

Two important structural factors that affect distillation efficiencies, the outlet weir heigh and the liquid flowpath length, are investigated. Performance and efficiency data of an industrial scale i-butane/n-butane distillation column equipped with two-pass trays are used as a basis for the calculations. A mathematical development for a new method for predicting the numbers of vapor and liquid phase transfer units is given. This method together with some other NTU calculation methods is used to assess the effect of the outlet weir height on efficiencies. The effect of outlet weir height on the Murphree tray efficiencies is investigated using the observed point efficiencies and different point efficiency to the Murphree tray efficiency relation methods. The effect of varying liquid flowpath lengths on efficiencies is studied by calculating the Murphree tray efficiencies for one-pass and two-pass trays. The results obtained using the NTU calculation method presented in this study show that a certain outlet weir height point efficiency reaches its maximum. Most of the other methods give opposite results giving a minimum for point efficiency at a certain outlet weir length. The results also show that the Murphree tray efficiencies for one-pass trays are higher than for two-pass trays. Obviously, this is caused by the longer liquid flowpath length of one-pass trays. The Murphree tray efficiencies are also calculated for an industrial-scale MTBE purification column. The column is equipped with two-pass trays in the stripping section and with one-pass trays in the rectifying section. The Murphree tray efficiencies of one-pass trays are considerably higher than the two-pass tray Murphree tray efficiencies.