小颗粒滴流床反应器的流体力学研究

在内径为０．０４７ｍ，床层高０．７ｍ的滴流床反应器内，采用空气－水－玻璃珠（１．８，３．１８ｍｍ）体系，在常温、常压下进行实验。气、液流速分别在０．０５４－０．２３ｋｇ／（ｍ＾２ｓ）和３．２０－１４．７３ｋｇ／（ｍ＾２ｓ）内，用电导信号脉动法、压降波动法结合目测法测定了滴流床的流动状态及其变化，实验结果可用于确定不同操作条件下的流动状态。本研究还分别是用差计、示踪剂法和体积法对滴流床的压降，总持流     

细颗粒滴流床的压降与传质

细颗粒滴流床在三种床径下实验,采用不同粒度的多孔玻璃球及实心玻璃球填料时的床层压降,可由两相摩阻因子f_(gl)的经验关系表示:lnf(gl)=7.38-1.32lnz+0.011(lnZ)~2-0.0077(lnZ)~3由氧解吸法测得床层内的容积传质系数K_la,它的关联方程为:k_la=0.00160E_L~(0.55)·u_g~(0.25)     

两相并流小颗粒滴流床反应器的压降和持液量的研究

在空气、水和小的固体玻璃或氧化铝球形颗粒床层中,测定了两相并流时压降和持液量。测定了流体流率、颗粒粒度及材质,分别对压降和持液量的影响,比较了大颗粒和小颗粒的特性,探计了前人的一些关联式,取得了满意结果。     

滴流床反应器的压降和持液量

在空气、水和固体玻璃或陶瓷球颗粒床层中,测定了两相并流时的压降和持液量。讨论了流体流率、颗粒粒度及材质对压降和持液量的影响,比较了大颗粒和小颗粒的特性,修正了前人的一些关联式。     

滴流床反应器中发泡流体的流型转变

滴流床反应器(TBR)广泛用于石油炼制和化工等过程．TBR的流体力学现象十分复杂,因操作条件、床层和流体性质的改变可产生不同的流区．其流型转变行为是TBR反应工程研究的一个重要领域．     

反应器床层压降异常初探

航煤装置现场生产过程中出现反应器床层压降异常的现象，结合现场工作经验初步分析异常原因并提出相应的解决措施。     

滴流床式固定化植物细胞反应器中的压降和持液量

滴流床式固定化植物细胞反应器中的压降和持液量袁丽红，周名立，欧阳平凯（南京化工学院应用化学系，南京２１０００９）关键词：滴流床反应器，固定化植物细胞，压降，持液量１前言植物细胞的固定化通常采用海藻胶进行包埋，然后源源不断地提供其营养成分并通入空气，以...     

Experimental Visualization and Investigation of Multiphase Flow Regime Transitions in Two-Dimensional Trickle Bed Reactors

Different flow regimes are known to occur in the interaction of multiphase gas–liquid flows over packed beds of solid particles, such as those observed in trickle bed reactors (TBRs). There are four major flow regimes that are known to occur in downward cocurrent flow in TBRs, namely: trickle, pulse, bubble, and mist flow regimes. In this work, the focus is on macro-scale experimental visualizations and investigations of the flow regimes in a two-dimensional TBR.

Experimental observations are made to investigate the development and transition of these flow regimes over a wide range of liquid and gas velocities. Cylindrical particles are placed between two glass plates that are sealed on the sides, and water and air are injected over them using an injection manifold to simulate multiphase flow in a TBR. A diffused light emitting device (LED) light table is used to illuminate the experimental window, while real time images are obtained using a high-speed camera. Flow maps are reported depicting all four regimes and the transition regions between them. Transition regions occur where the characteristics of more than one flow regime coexist.

The 2D experimental results are then compared with the existing literature data of three dimensional results and found to be in good agreement. Emphasis is placed on the transition between the trickle and pulse regimes, since that is the most important mode of operation in industrial TBRs. It is observed that the change in diameters of the cylindrical particles in a two-dimensional TBR has little effect on the transition between the flow regimes when the porosity of the bed is kept constant.     

Fractal Characterization of Liquid Dispersion in Trickle Bed Reactor

INTRODUCTIONDispersionisveryimportanttothedesignoftricklebedreactorforbothchemicalandbiochemicalprocesses Thedegreeofdispersionofteninfluencesreactor　　performanceandscale up Thetraditionalmethodformodelingdispersionprocessesintricklebedreactorsisbasedontheconvective diffusionequation (CDE) Themostcommonlyusedisthelongitudinal dispersionmodel[1,2 ] Themagnitudeofliquiddispersionisusuallyconsideredindependentofpositionalongthelongitudinaldirectionofthereactor Themainassumptionofthelongitudinal dispersionmod...     

Intensification of Deep Hydrodesulfurization Through a Two-stage Combination of Monolith and Trickle Bed Reactors

Deep hydrodesulfurization (HDS) is an important process to produce high quality liquid fuels with ultra-low sul-fur. Process intensification for deep HDS could be implemented by developing new active c...     

在滴流床反应器中油脂醇解反应的初步研究

在滴流床反应器中进行了油脂醇解反应的初步研究,脂肪酸甲酯的产率达95％以上。该法克服了间歇搅拌反应釜的一些缺点,不仅减少了功率消耗,降低了生产成本,而且可实现连续化生产。对生物柴油的产业化研究具有一定的意义。     

循环流化床下料立管内气固两相流动状态与压力脉动的关系

在15 m高的大型气固循环流化床上对内径90和42 mm的下料立管内气固两相流的动态压力进行了测量. 实验结果表明,负压差下料立管内的气固两相流动存在着低频压力脉动,压力脉动的强度可以用动态压力的标准方差(Standard deviation, Sd)来表征,且与立管下料的流动状态密切相关. 立管下料的流动状态依据颗粒质量流量通量的大小有浓相输送状态和稀密两相共存两种状态. 浓相输送状态的压力脉动强度较大,是下行颗粒压缩其夹带气体引起气固两相强烈相互作用导致的;稀密两相共存状态的压力脉动强度较小,是密相段排料的不稳定性和稀相段较弱的气固相互作用共同引起的. 立管下料的压力脉动强度随颗粒质量流量通量的增加而增大,对于浓相输送状态,在实验操作范围内[Gs'=550~850 kg/(m2×s)],压力脉动的强度与立管下料质量流量通量近似成Sd=0.00875Gs'-4.77的线性关系.     

Analysis of Operating Variables in the Catalytic Purification of Butene-1 in a Trickle Bed

A mathematical model for analyzing and simulating selective hydrogenation of butyne-1 and 1,3-bu-tadiene in industrial trickle bed reactors operated to obtain high purity butene-1 is presented in this work.Fromthe analysis of typical operating conditions,only the relevant phenomena are finally retained in the model formu-lation.The model is then employed to analyze the effect of operating variables and catalyst selectivity in processperformance.In particular,the search for the minimum hydrogen flow rate necessary to fulfil butene-1 purityspecifications is undertaken.     

计算流体力学在填充床反应器中的应用进展

在使用计算流体力学(CFD)方法模拟填充床反应器时,为了描述填充床中的气液流动情况,目前主要运用基于体积平均法的双流体数学模型,辅以空隙率分布,填料润湿效率以及轴向扩散等经验关联式来计算填充床中的压降、持液量、停留时间分布等重要参数。近年来填充床反应器CFD数学模型韵几个研究重点是动量交换系数、毛细管压力以及床层空隙率的非均匀分布性。简要介绍了涓流床、固定床、填料塔等填充床反应器及其内部构件研究中CFD软件模拟的应用进展情况和发展趋势。