立体并流板的流体力学和传质性能

新型立体连续传质液体并流塔板是将LLC-Tray与两种并流流型相结合开发而成的新型塔板。通过实验测定了新型塔板的干、湿板压降,雾沫夹带,漏液等流体力学性能和传质性能,并进行关联得到了相应公式。结果表明,新型塔板板压降较低,雾沫夹带较低,液体处理量相对LLCT提高30%。     

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。     

三种固阀塔板的性能比较

为了研究固阀的尺寸大小对塔板性能的影响,采用空气-水系统,在直径1200mm不锈钢塔内,对3种结构相似、尺寸不同的固阀塔板,在不同堰高、不同溢流强度的条件下进行了流体力学与传质性能测试,测定了塔板压降、漏液、雾沫夹带与传质效率。实验结果表明:随着固阀尺寸的减小,雾沫夹带降低,传质效率增高;随着阀缝面积与阀孔面积比例的减小,干板压降与湿板压降增加,漏液减少;尺寸越小的固阀,综合性能越加优异。     

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。     

垂直筛板塔流体力学与传质研究状况

对我国在新型垂直筛板塔的流体力学性能 ,诸如塔板干板压降与湿板压降、板孔漏液、塔板过量雾沫夹带、板上帽罩单元的液体提升能力与液体循环程度的研究及其传质性能 ,诸如塔板传质效率模型、塔板空间气相中液体大小与分布、板间空间立体传质作用的研究等进行了综合 ,并予以分析论述 ,从中看出我国对新型垂直筛板塔已进行了较全面深入的研究工作 ,并取得了新进展。     

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。     

宝塔罩型塔板性能研究

开发了一种宝塔罩型塔板。该塔板是在塔板上设置数个由板孔、升气筒、塔型罩、进液孔所构成的豆塔罩单元，在单元内气液呈喷射状态接触，实现两相传热传质。流体力学性能和传质性能研究证明：该塔板压降、氧解析效率、漏液等性能与新型垂直筛板相当，但雾沫夹带要比新型垂直筛板低。因而该塔板具有较大的生产处理能力和较宽的稳定操作范围。     

新型矩形垂直筛板的研究

研究了一种矩形垂直筛板.该塔板是在塔板上设置数个由板孔、升气筒、矩型罩、底隙所构成帽罩单元,在单元内气液呈喷射状态接触,实现两相传热传质.流体力学性能和传质性能研究证明该塔板压降、漏液等性能与新型垂直筛板相当,但雾沫夹带要比新型垂直筛板低.因而该塔板具有较大的生产处理能力和较宽的稳定操作范围.     

新型立体传质塔板及其流体力学性能

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.     

低雾沫导向梯形固定阀塔板流体力学性能

开发了一种低雾沫导向梯形固定阀。采用空气-水系统,在1 500 mm×400 mm的矩形塔内,对低雾沫导向梯形固定阀塔板的流体力学性能进行了实验研究,通过改变气体流量、液流强度以及出口堰高,测定了塔板的压降、雾沫夹带及漏液。结果表明:低雾沫导向梯形固定阀塔板的压降和雾沫夹带率较低,泄漏率较高。从整体上比较,相比于F1浮阀有明显改观,综合性能优异;与半椭圆固定阀相比,雾沫夹带明显降低,干湿板压降略高但相差不多,漏液性能持平,总体上性能良好。根据实验结果,回归得到压降、雾沫夹带、泄漏的计算公式,对工程的实际应用起指导作用。     

气液并流筛板式填料压降的数值模拟

基于欧拉-欧拉模型,采用CFX软件对筛板式填料的气液两相并流流动进行了模拟。将模拟所得的压降与填料的出厂特性值进行了对比,发现在液气动能参数较小的情况下,两者吻合较好。分析了该流场内的速度分布和压力分布的特点,射流卷吸作用使流场内两相流体混合,但涡旋使筛板下方压强减小,射流撞击使筛板上方压强增加。对不同结构的矩形筛板式填料的压降进行研究,结果表明：筛板孔径和液相流量是影响筛板压降的重要因素,开孔直径越小,液相流量对单板压降的影响越大;上层筛孔投影与下层筛孔相交的结构更能有效降低单板压降。液相流量较大时,两个不同板间距的单板压降曲线将相交于一点,气相流量低于此交点时,板间距越小,单板压降越大;气相流量高于此交点时,则相反。     

Nye Tray Versus Sieve Tray: Experimental Study on Hydrodynamic Parameters

The hydrodynamic parameters of a Nye tray were investigated by performing experiments in a tower with a diameter of 1.22 m. Air was used as the gas phase and water was used as the liquid phase. A number of parameters such as the dry pressure drop, the total pressure drop, the clear liquid height, the froth height, and the entrainment were measured. A tray stability factor was obtained using the amount of weeping, the clear liquid height, the dry pressure drop, and the Froude number. All experiments were repeated for the matching sieve tray under the same conditions. Ultimately, advantages and disadvantages were compared, and the results demonstrated that the Nye tray has a couple of advantages over the sieve tray, except that the sieve tray is slightly more stable.     

Hydraulics and efficiency of screen trays for distillation

Screen trays are proprietary devices similar to sieve trays which are used in distillation and absorption applications. The pressure drop, liquid holdup and entrainment are measured for screen trays in an air/water column and compared to results obtained with sieve trays. The effciencies of both types of trays were compared in a distillation column using systems of various physical properties (methanol/water, acetic acid/water and cyclohexane/n-heptane mixtures). It was found that the screen tray has a lower dry pressure drop, higher liquid holdup, lower entrainment and weeping, and higher jet flooding capacity than the sieve tray. However, the effciencies of both trays are similar for the systems studied. A model was developed for predicting total pressure drop for screen trays using an air/water column. The model was tested using results for methanol/water, cyclohexane/n-heptane and acetic acid/water systems at total reflux. The deviations are within +/- 20% for 90% of the data points. The effect of a bed of mesh packing on the screen tray was also studied. It was found that the packing led to a higher tray effciency, but resulted in a higher tray pressure drop.     

HYDRAULICS AND EFFICIENCY OF SCREEN TRAYS FOR DISTILLATION

Screen trays are proprietary devices similar to sieve trays which are used in distillation and absorption applications. The pressure drop, liquid holdup and entrainment are measured for screen trays in an air/water column and compared to results obtained with sieve trays. The effciencies of both types of trays were compared in a distillation column using systems of various physical properties (methanol/water, acetic acid/water and cyclohexane/n-heptane mixtures). It was found that the screen tray has a lower dry pressure drop, higher liquid holdup, lower entrainment and weeping, and higher jet flooding capacity than the sieve tray. However, the effciencies of both trays are similar for the systems studied. A model was developed for predicting total pressure drop for screen trays using an air/water column. The model was tested using results for methanol/water, cyclohexane/n-heptane and acetic acid/water systems at total reflux. The deviations are within +/- 20% for 90% of the data points. The effect of a bed of mesh packing on the screen tray was also studied. It was found that the packing led to a higher tray effciency, but resulted in a higher tray pressure drop.     

垂直筛板和T形排列条形浮阀塔盘的初步研究

在φ300mm的实验塔中,用水-空气系统对“T”形排列条形浮阀塔盘及“VST”塔盘的流体力学性能及氧解吸效率做了实验研究。得出了塔板压降、泄漏、夹带、液层阻力降以及降液管中清液层高度的初步关联式。 在相同实验条件下与F_1型浮阀塔盘的数据对比、分析的基础上,发现了VST和T形排列条形浮阀塔盘的分离效率和板压降与F_1型浮阀塔盘相当,而操作范围要比F_1型浮阀宽。     

网填筛板流体力学性能研究

在直径为600mm有机玻璃塔内,以水-空气系统对放置网孔填料层的筛板(称网填筛板)和普通筛板进行了流体力学性能对比实验。研究发现,在普通筛板上加一层厚度为15mm的网孔填料,可以使雾沫夹带明显减少,负荷上限提高50％～80％。同时,塔板压降和漏液有所增加。     

Hydrodynamics and mass transfer performance analysis of flow-guided trapezoid spray packing tray

Distillation is the most common separation technology utilized in the petroleum and chemistry industries. Due to the wide usage of the distillation column, even a small improvement in performance may result in significant energy cost savings. Aiming to improve the hydrodynamics and mass transfer performance, the flow-guided trapezoid spray-packing tray (FTS-PT) was designed by combining flow-guided holes and trapezoidal caps with structured packing. And the experimental measurements of the FTS-PT, including pressure drop, clear liquid height, weeping, entrainment, and tray efficiency, were conducted in a 500 mm diameter plexiglass column with the air-water-oxygen system. Moreover, the performance of the FTS-PT was compared with that of new vertical sieve tray (New VST) and F1 valve tray. The results show that FTS-PT has a significant advantage in pressure drop, entrainment, and capacity. Furthermore, the calculation model of the pressure drop was derived and used for the FTS-PT with a relative deviation of less than 5%.     

抛物线椭圆斜孔塔盘性能研究

介绍了抛物线椭圆斜孔塔盘(简称PEST)的结构特点和实验研究情况。以空气和水为工质进行了冷模实验,研究了PEST的塔板压降、雾沫夹带量和泄漏量等流体力学性能;利用CO2解吸法测定其塔板效率,并在相同条件下与筛孔塔板进行了对比实验。结果表明:在其操作弹性范围内,PEST比传统筛板的雾沫夹带量和泄漏量与筛板相比分别平均减少了29.6%,55.5%,塔板效率平均提高约37.7%,是一种综合性能优良的新型斜孔塔板。     

新结构95型塔板的流体力学性能

引　言传统的板式塔塔板开孔率有限 ,当处理量较大时 ,压降较高 ,板效率降低 .因此开发新型大通量高效率塔板具有重要的现实意义 .本研究通过改进降液管结构和板面设计 ,提高塔板的有效传质区面积 ,开发了一种新型大通量塔板——— 95型塔板 ,因该板的有效传质区面积约占全部塔板面积的95%而得名 .本文以水和空气体系对 95型塔板进行了流体力学和流动性能试验 ,同时与传统筛板进行了比较 ,对试验测定的数据进行了关联 .1　试验装置及筛板结构参数试验塔为一直径Φ1 0 0 0ｍｍ的不锈钢塔 .塔内设置两块塔板 ,上板为测试板 ,下板为气体分布板 …