液体黏度对CO_2吸收塔规整填料传质性能的影响

为了有效提高CO2捕集过程中的传质效率,需要测量规整填料在不同溶液体系下的传质性能。在氢氧化钠水溶液-空气-CO2体系的基础上,通过向液相加入甘油的方法,使液相黏度由0.001 Pa·s最高增加至0.002 5 Pa·s。这一改变使实验体系更加接近真实的CO2吸收体系,如乙醇胺、二乙醇胺水溶液等。利用此改进后的体系,在直径为200 mm、填料高度为800 mm的填料塔中,测量了波纹倾角为45°、齿顶角为90°、波纹峰高为9 mm的金属板波纹规整填料在不同操作条件下的有效传质面积。实验结果显示:黏度的改变直接影响到填料在同等条件下的有效传质面积。在实验的基础上,将黏度参数关联到新的关联式中,可以有效预测在不同黏度体系下的有效传质面积,计算值与实验值吻合较好。     

规整填料传质性能计算的研究进展

综述了规整填料传质性能的计算方法和模型,并对这些模型的理论基础和适用条件进行了分析和比较。归纳了近年来对于传统规整填料传质模型的修正和扩展,并对影响传质性能的有效比表面积的经验关联式进行了讨论,指出了规整填料传质性能研究方面进一步的探索方向和应改进的若干问题。     

规整填料和散堆填料传质性能比较

通过对苯 -甲苯精馏传质系数的计算 ,比较了规整填料 ( 2 5 0 Y)和散堆填料 ( 5 0 #鲍尔环 )的传质性能。结果表明 ,规整填料的传质性能优于散堆填料。这一优势主要得益于前者的比表面积远大于后者。若以传质系数 k L、k G来比较 ,新型散堆填料要强于规整填料。如何提高规整填料单位面积的传质强度是新型规整填料发展的重要方向     

规整波纹填料内气体流动和传质的CFD模拟

为了研究规整填料局部特征单元内流体的流动状况和传质效果,采用计算流体力学的方法对JKB-250Y交叉波纹填料以及增加隔板后的JKB-250Y交叉波纹填料进行了模拟计算比较。结果表明,加入隔板后有效改善了传质的局部均匀性,并且消除了两股气体交叉流动带来的阻力,降低了通道的单位压降。增加隔板后的交叉波纹填料压降比传统交叉波纹填料压降降低20%~50%,增加隔板后的交叉波纹填料传质系数比传统交叉波纹填料传质系数提高约20%,可见提高传质分布的局部均匀性是提高传质效率并且降低阻力的较为有效途径之一。     

规整填料在化肥工业吸收塔上的应用

介绍规整料与新型分布器的特性，及其在中、小型化肥厂的脱硫、脱碳、铜洗等工艺中应用的生产数据和成功范例。     

新型网架规整填料的传质性能

对一种新型网架规整填料用于萃取时的传质效率进行了实验研究。在Φ50mm的填料萃取塔中,选用煤油–苯甲酸–水和30%TBP(煤油)–乙酸–水两种不同界面张力的物系,测定了该填料和Φ10mm的鲍尔环填料在不同操作条件下的表观传质单元高度。扣去影响因素,网架填料的表观传质单元高度至少会比鲍尔环填料低25%,而网架填料的堆积密度仅为鲍尔环的38%。同时对影响传质的因素进行了分析,并针对该填料的特点,提出了优化设计原则。     

泡沫碳化硅波纹规整填料的流体力学及传质性能

将碳化硅陶瓷材料用于精馏过程,将该材料与波纹板类填料形状相结合开发出泡沫碳化硅波纹规整填料和光滑碳化硅波纹规整填料.对2种填料进行了流体力学性能与传质性能的测试,研究了泡沫结构对规整填料性能的影响.在直径100mm的有机玻璃塔中使用空气-水体系对填料进行干填料压降、湿填料压降、泛点气速、持液量等流体力学性能测试;在直径100mm的常压玻璃塔中,使用环己烷-正庚烷标准物系进行全回流操作,对填料进行传质性能测试.实验结果表明,在填料外形相同的情况下,与光滑填料相比,泡沫填料的干、湿填料压降较高,泛点气速相当,持液量增大,传质效率显著提高.     

新型组合式规整填料在液液萃取中的传质性能

采用质量分数30%磷酸三丁酯-煤油-醋酸-水物系,对一种新型萃取用组合式规整填料的传质性能进行了测定,考察了连续相流速和分散相流速对其传质效率的影响。实验结果表明:在相同的二相流速下,组合式规整填料的表观传质单元高度比16 mm鲍尔环平均低约54%。固定连续相流速,随着分散相流速的增加,填料的表观传质单元高度降低,传质效率提高;固定分散相流速,随着连续相流速的增加,填料的表观传质单元高度增大,传质效率降低。     

规整填料在高压精馏条件下的传质性能

Performance of Mellapak 250Y and 350Y corrugated structured packing in distillation applications at pressures ranging from 0.3 to 2.0MPa is analysed by using HTU-NTU method.These data are obtained in distillation column with 0.15m diameter operated with n-butane/n-pentane system at total reflux.In considering the axial backmixing effects.the height of an overall gas phase transfer unit,HTUOG,is divided into two parts.One part represents the height of an overall gas phase transfer unit,without backmixing, designated as HUTOG,and the other part,designated as the height of a backmixing unit(HBUO),accounts for the backmixing effects.The HTUOG is evaluated from the measured concentration profile of n-butane in liquid phase.The HBUO obtained experimentally is correlated in terms of the properties of the materials being separated and the equivalent diameter of the structured packing.Our result shows that HBUO varies from 0.12 to 0.34m as pressure increases from 1.0 to 1.9MPa.It indicates that the overall efficiency of the structured packing decreas gradually at high pressure,as a result of the vapor backmixing.     

规整填料塔中氨水吸收CO2的体积总传质系数

目前,CO₂排放问题已经成为世界各国可持续发展面临的重要挑战。以化学溶剂吸收法工艺为基础的燃烧后脱碳是当前比较成熟的已进入工业规模实验的技术路线。而氨水作为一种新的吸收剂受到广泛关注。以气相体积传质系数（K_Ga_e）作为表征,对规整填料塔中氨水吸收CO₂的传质性能进行了研究,探索了气速、CO₂分压、液速和氨水浓度对K_Ga_e的影响。实验结果表明,在本文的工况条件下,K_Ga_e随液速和氨水浓度的增大而增大,随CO₂分压的增大有所减小,气速对K_Ga_e的影响不大。实验结果对今后填料塔的设计工作的经济性和合理性有一定指导作用。     

湿法烟气脱硫工艺中吸收塔传质性能及其强化

介绍了湿法烟气脱硫工艺中吸收塔的传质机理、影响因素和设备结构形式,指出吸收塔应从4个方面进行设备传质强化采用高气速、增加气体均布装置、新型的喷嘴设计及排列和对塔内件的设计研究.讨论了强化吸收塔传质性能的措施和途径.     

Direct heat and mass transfer in structured packings

Direct heat transfer is an important method in the exchange of heat between two countercurrent process streams within a column. The process can be simulated using either the theoretical stage or the rate based concept. With both concepts, a reliable heat transfer coefficient is needed. Additionally, the rate of the heat transfer coefficient is influenced by the simultaneous mass transfer.

A number of application-dependent methods to estimate the heat transfer coefficient have been developed, mainly for random packings. It is the purpose of this paper to extend this work to structured packings.

A number of experiments with air/water have been performed in a column of 300 mm inner diameter with Mellapak 250.Y, 250.X and 125.X at ambient conditions. A second group of measurements were done using an oil/air system where only sensible heat was transferred.

Based on these experimental results a method was developed to predict the heat transfer coefficient for structured packings. The method is applied to examples of industrial importance, like a gas quench, a gas saturator and a pump-around zone in an atmospheric tower.     

Mass transfer to regular packings in single phase

A study of mass transfer to regular packings by the electrochemical technique is presented in this paper. The excellent properties of radial mixing were verified and the correlation for mass transfer rate was also obtained. It was found that the energy efficiency, which is represented by the LeGoff number, is higher than that of other packings due to the low pressure drop shown by these arrangements.     

泡沫铁铬镍规整填料的性能实验研究

为了考察泡沫铁铬镍规整填料的性能,对电沉积法制备的泡沫铁铬镍规整填料进行了流体力学和传质性能实验。结果表明:泡沫铁铬镍规整填料的压降随F因子和喷淋密度的增大而增大,液泛点的Ff因子达到2 m/(s·kg~(0.5)·m~(1.5))以上,且每米填料的理论板数达到3块板以上。相比铸造法制备的泡沫铝和泡沫碳化硅规整填料,泡沫铁铬镍规整填料的压降低、持液量小、操作弹性大,其传质性能与传统规整填料M250Y和BX500相当。在实验基础上,拟合了泡沫铁铬镍规整填料的压降关联式和液泛气速关联式,为今后的工业化设计提供指导。     

Mass transfer improvements in single phase in regular packings

Two ways of enhancing liquid to solid mass transfer in regular packings are proposed and investigated: the introduction of a fluidized bed of inert particles and of turbulence promoters by constructing the packing from expanded metal. It is shown that both systems can be of considerable benefit in improving the mass transfer performance: up to 200% in the first case and up to 130% in the second case. However, the energy dissipated by fluidized particles is excessive in comparison to that consumed by turbulence promoters.     

Mass transfer in structured corrugated packing

The performance of structured corrugated packing has been simulated by establishing mechanistic models for liquid distribution, liquid flow on the packing surface and mass transfer. The models were used to investigate the effect of packing height, liquid load, initial maldistribution as well as differing initial distribution and solid-liquid contact angle on the packed column performance. Wetted surface area is the primary value of interest and the simulated results compare very well with those predicted by Onda (1968). The results clearly demonstrate that the wetted surface area is a strong function of the solid-liquid contact angle. Other predicted values such as mass transfer coefficients and overall height of a transfer unit show reasonable agreement with published data.     

Experimental study of mass transfer on structured packings of direct-contact crossflow heat exchangers

Some experimental results of studying mass transfer during the evaporation of a liquid film from the surface of flat-plate and corrugated perforated packing into an air flow have been presented. An empirical equation for calculating the average coefficient of mass transfer with allowance for the effect produced by temperatures of heat-transfer agents, their physical properties, and flow rates, as well as the geometrical dimensions of a packed bed, on the mass-transfer process has been given.     

大庆乙烯装置利用CO2汽提塔降低轻烃原料中CO2含量

中国石油大庆石化公司化工一厂老区乙烯装置轻烃原料CO2的含量高,影响装置平稳运行。增加轻烃CO2汽提塔AT-001后,能够将轻烃原料中CO2的含量降低,控制在合适范围内。