低喷淋密度下P-S复合塔板的持液特性研究

填料-筛板复合塔板是一种被用于高气液比吸收处理过程的塔内构件,其持液量与液相停留时间对传质传热具有重要影响,为此进行了相关性能的研究.测定分析表明:P-S复合塔板的持液量可通过填料液膜区持液和浸润填料区持液两部分进行估算,停留时间可在实验基础上据模型计算.同时,在单因素实验条件下,P-S复合塔板的动持液量随喷淋密度的增...     

提高悬挂式矩形降液管塔板效率的研究

分析了影响悬挂式矩形降液管塔板(DJ塔板)效率的原因,并提出在塔板的受液区安装防冲击漏液装置以及在塔板下方复合填料来提高塔板的传质效率.在一(Φ)300 mm的热模塔内,以乙醇-水为物系,全回流的情况下测定了受液区设置防冲击漏液装置以及塔板下方复合规整填料的DJ塔板的全塔效率.试验结果表明受液区设置防冲击漏液装置的DJ塔板的塔效可提高5%～10%;塔板下方复合100 mm规整填料的DJ塔板的塔效可提高15%～25%,比弓形降液管F1型浮阀塔板高5%～15%.     

立体连续传质复合塔板流体力学特性

通过分析板式塔与填料塔各自的优缺点,在梯矩形主体连续传质塔板的基础上,提出一种由喷射型塔板、规整丝网填料及其附件构成的复合塔板.实验考察了操作条件与几何结构等因素对该复合塔板流体力学性能的影响.结果表明：与其他板式塔板相比,该塔板在相同的操作条件下具有压降更低、通量更大、操作弹性更高、雾沫夹带更小等优点.     

液体并流塔板技术进展

液体并流塔板,即相邻2层塔板上液体流动方向相同,能有效提高塔板效率。文中介绍了国内外并流塔板的板效率模型的发展状况,对国内外开发的各种并流塔板结构及性能进行了分析,并考察了立体传质塔板的性能及工业应用情况。为了开发适合大塔径的高效塔板,基于液体并流板型能提高板效率的机理,结合性能优良的立体传质塔板,采用特殊的降液结构,提出了一种新型液体并流复合塔板的结构型式。新型塔板具有气、液体处理量大、传质效率高、操作弹性大的特点,而且有效避免了普通逆流板型的液体滞留区的产生。     

高效复合型塔板及其在甲醇精馏中的应用

高效复合型塔板采用筛板和薄层规整填料的复合结构,有穿流筛板复合填料和DJ型塔板复合填料两种型式.复合结构充分利用了塔板间的空间,改善了塔内的气液分布,抑制了板阍雾沫夹带,提高了操作弹性,具有优良的流体力学性能和传质性能.穿流型复合塔板在低温甲醇洗的甲醇精馏塔中成功地代换了林德泡罩和一般筛板或浮阀塔板,提高了分离效率20%以上,增加了处理能力,降低了回流比,改善了腐蚀问题,节省了系统的能耗.穿流型复合塔板还成功地应甩于甲醇生产装置的精馏塔系中.在甲醇三塔精馏塔系中,粗馏塔和加压精馏塔的精馏段采用穿流型的复合塔板,而提馏段则采用通量大弹性好的DJ型复合塔板.实现最佳的组合,满足塔内操作工况的要求.     

高效复合型塔板及其在甲醇精馏中的应用

高效复合型塔板采用筛板和薄层规整填料的复合结构，有穿流筛板复合填料和DJ型塔板复合填料两种型式。复合结构充分利用了塔板间的空间，改善了塔内的气液分布，抑制了板间雾沫夹带，提高了操作弹性，具有优良的流体力学性能和传质性能。穿流型复合塔板在低温甲醇洗的甲醇精馏塔中成功地代换了林德泡罩和一般筛板或浮阀塔板，提高了分离效率20％以上，增加了处理能力，降低了回流比，改善了腐蚀问题，节省了系统的能耗。穿流型复合塔板还成功地应用于甲醇生产装置的精馏塔系中。在甲醇三塔精馏塔系中，粗馏塔和加压精馏塔的精馏段采用穿流型的复合塔板，而提馏段则采用通量大弹性好的DJ型复合塔板，实现了最佳的组合，满足了塔内操作工况的要求。     

蒸馏过程中旋转填料床的传质和流体力学特性

建立了一套完整的精馏实验装置,以甲醇-水溶液为物系,在常压、全回流操作条件下,研究了旋转填料床的传质和流体力学性能. 结果表明,旋转填料床的理论塔板数随超重力因子和气相动能因子的增大出现峰值,理论塔板高度最小为0.0109 m;气相压降随气相动能因子、超重力因子的增大而增大. 在实验基础上应用最小二乘法建立了旋转填料床的传质、压降实验关联式.     

分散降液筛板塔传质性能

在筛板塔的基础上,研发了一种新型板式塔--分散降液筛板塔,将传统筛板塔的弓形降液管改为均布于塔板筛孔间的多降液管结构,使整个塔板面成为均匀降液和受液的传质区,并新增淋降和喷溅传质区,在全塔空间内实现立体、连续的微分接触式气液传质过程,另外,塔板之间可以加装填料来强化传质,或装填催化剂以促进伴随化学反应的传质过程。以“氧气-空气-水”为体系,初步研究了分散降液筛板的传质性能及其影响因素,并与传统筛板进行比较,结果表明:分散降液筛板气液分布均匀,接触充分,在同等条件下传质效率比传统筛板提高了8.4%~9.7%。     

泡沫铁镉镍和泡沫铝复合规整填料的实验研究

利用泡沫金属规整填料各自的优点,将泡沫铁镉镍填料与泡沫铝填料组合成新型复合规整填料,并用空气-水、环己烷-正庚烷物系分别对其进行流体力学性能实验和传质实验。实验结果表明:在相同条件下,新型复合规整填料比AlCY复合填料压降降低约70%,和CY丝网填料接近,同时具有较高的泛点气速,操作弹性大,持液量较大,其理论塔板数可达5块以上。这说明新型复合规整填料结合了泡沫铁镉镍填料和泡沫铝填料的优点,其分离效率介于AlCY复合填料和CY填料之间,是一种优秀的新型复合填料。     

精馏塔负荷性能图分析技术新发展

系统介绍了按照流体力学极限和传质操作限制来构造精馏塔负荷性能图的方法.提出了适用于进料条件全面变化的可行稳定域分析方法,将塔板负荷性能图分析由一条线拓展到一个面;首次以平衡级离散填料床的方法构造了填料塔的负荷性能图;推荐以降液管入口液速作为负荷性能图的横坐标,不仅统一了塔板负荷性能图的纵、横坐标单位,也为塔板/填料混合型精馏塔实现全塔分析奠定基础.在此基础上提出了全塔负荷性能图的新分析方法,将精馏塔的分析由单层塔板、单段填料上升到全塔的范畴,进行精馏塔瓶颈分析、塔板/填料匹配设计十分容易、便利,是最简单的精馏塔瓶颈分析方法.     

Mass transfer and hydraulics of packed sieve trays

The hydraulics and mass transfer performance of wire-mesh-packed sieve trays have been studied for their use in the distillation of acetic-acid-water mixtures, a surface-tension negative system, in a 150 mm diameter column. It was found that packing led to a larger capacity, higher mass transfer efficiency, lower entrainment and slightly greater pressure drop. These results are similar to those obtained for the distillation of methanol-water mixtures, a surface-tension positive system. Surface tension effects on efficiency and transition point are also discussed. Hydraulic tests in a 600 mm diameter air-water column showed a similar effect of packing on tray pressure drop, capacity and entrainment for sieve trays with hole diameters in the range from 7 to 12.5 mm.     

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.     

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%.     

Performance of combined mesh packing and sieve tray in distillation

The hydraulic and mass transfer performance of a combined knitted mesh packing and sieve tray has been measured for the distillation of methanol-water mixtures. It was found that by adding a shallow bed of packing, the Murphree tray efficiency increased by 40–50% over a wide range of concentrations and flow rates. This increase in tray efficiency can be attributed to a much smaller and more uniform bubble formation on the packed tray. Hydraulic measurements have shown that the packed trays have lower weeping and entrainment, as well as slightly higher froth heights and pressure drops.     

Study on Jet Coflow Packing Tray

Experimental study on hydrodynamics and mass transfer efficiency of jet coflow packing tray (JCPT) was conducted in a φ285 mm column and a φ200 mm column, respectively. Compared with new vertical sieve tray which has been applied in the petrochemical industry since 1968, the JCPT has lower pressure drop, higher capacity and higher mass transfer efficiency, and seems promising in commercial application.     

并流喷射填料塔板流体力学及传质性质性能的实验研究

The jet co-flow packing tray(JCPT) with three different types of perforation in equal opening fraction was tested in two rectangular columns with 0.12 m in width and 0.27 m in length operated with air-water system.The influences of gas phase orifice F-factor and clear liquid height He on the amount of liquid lifted, Q, were examined. The corresponding correlation between Q with F-factor and equivalent diameter of perforated holes as well as Hc was obtained. Furthermore, the non-steady state mass transfer performance of JCPT was tested by the humidification of air with water. Finally, by the analysis of data and comparison, it was found that the JCPT tray with single cap and two holes exhibited the highest mass transfer efficiency and best performance.     

计算传质法预测精馏塔效率(英文)

A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified two equations formulation for closing the differential turbulent mass transfer equation with improvement by considering the vapor injected from the sieve hole to be three dimensional. The predicted concentration distributions by using proposed model were checked by experimental work conducted on a sieve tray simulator of 1.2 meters in diameter for de-sorbing the dissolved oxygen in the feed water by blowing air. The model predictions were confirmed by the ex-perimental measurement. The validation of the proposed model was further tested by comparing the simulated re-sult with the performance of an industrial scale sieve tray distillation column reported by Kunesh et al. for the strip-ping of toluene from its water solution. The predicted outlet concentration of each tray and the Murphree tray effi-ciencies under different operating conditions were in agreement with the published data. The simulated turbulent mass transfer diffusivity on each tray was within the range of the experimental result in the same sieve column re-ported by Cai et al. In addition, the prediction of the influence of sieve tray structure on the tray efficiency by using the proposed model was demonstrated.     

翅片导流板填料应用于旋转填料床的特性

For an alcohol/water system and with fin baffle packing, continuous distillation experiments were carried out in a rotating packed bed (RPB) system at atmospheric pressure. The effects of the average high gravity factor (β), liquid reflux ratio (R) and feedstock flux (F) on the momentum transfer and mass transfer were investigated. The gas phase pressure drop of RPB increased with the average high gravity factor, liquid reflux ratio and feedstock flux, which was 13.55-64.37 Pa at β of 2.01-51.49, R of 1.0-2.5, and F of 8-24 L&;#8226;h－1 for a theoretical tray in the RPB with fin baffle packing. The investigation on the mass transfer in the RPB with different packings showed that the number of transfer units of RPB with a packing also increased with the average high gravity factor, reflux ratio and feedstock flux. It is found that the fin baffle packing (packing III) presents the best mass transfer performance and lowest pressure drop for the height equivalent to a theoretical plate (HETP), which is 6.59-9.84 mm.     

提高复合塔板操作弹性和通量研究

在内径为 5 0 0mm和 30 0mm的塔内 ,以空气 水为物系 ,测定了不同结构 (浮阀 筛孔穿流板、非均匀开孔率穿流板、双孔径穿流板 )的穿流板与 2 5 0Y规整填料组成的各种复合塔板的流体力学性能。试验结果表明 :浮阀 筛孔复合塔板操作弹性小、气液处理量小 ;非均匀板复合塔板与均匀板复合塔板相比 ,操作弹性大2 0 %— 6 0 % ,气处理量大 2 0 %— 80 % ,液处理量大 70 %左右 ;双孔径复合塔板比单孔径复合塔板处理量略微增大 ,操作弹性高达 3.5以上。