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G.Q. Wang Z.C. Xu Y.L. Yu J.B. Ji 《Chemical Engineering and Processing: Process Intensification》2008,47(12):2131-2139
As a new kind of rotating equipment, rotating zigzag bed (RZB) is structurally unique and has many superior features. The RZB is characterized by a rotor coaxially combining a rotating disc with a stationary disk. Compared with a conventional rotating packed bed (RPB), the RZB can function without liquid distributors, eliminate one dynamic-seal, and easily accommodate and accomplish intermediate feeds in continuous distillation processes. The RZB also effectively increases the contact time of gas and liquid phases and thus, enhances the mass transfer capacity. In this work, the principles of the RZB are presented. The hydraulic and mass transfer performance of the RZB was investigated. Experimental results showed that the pressure drop of the RZB increases with the increase of the rotational speed and the gas flow rate, but decreases with the increase of the liquid flow rate. A semi-empirical equation was proposed to correlate the pressure drop data with good agreement. The mass transfer efficiency of the RZB decreases with the increase of the reflux rate at lower reflux rate, but levels off at higher reflux rate. The number of theoretical plates of the RZB increases with the increase of rotational speed of the rotor. However, at a higher rotational speed, this trend is not obvious. In addition, some considerations for further work are discussed. 相似文献
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折流式超重力旋转床转子结构对气相压降的影响 总被引:2,自引:1,他引:1
折流式超重力旋转床是继旋转填料床之后出现的一种新型高效的气液传质设备.今采用空气-水系统对折流式旋转床进行了气相压降实验,考查了折流式转子结构对气相压降的影响,建立了折流式旋转床干床气相压降的理论模型.实验结果表明:折流式旋转床转子结构对气相压降影响较大,在动静折流圈结构不变的情况下,动静盘垂直间距存在某一最优值,通过实验得到了实验中所用的折流式旋转床的最佳转子高度为90 mm,实验也验证了旋转床设计时采用的等通流面积原则是符合气体运动规律的;干床压降理论模型的计算结果与实验值符合较好,为建立湿床压降模型奠定了基础. 相似文献
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折流式旋转床是一种新型的同心圈式超重力设备,电机功率消耗是折流式旋转床设计时需要考虑的重要因素.本文对折流式旋转床的有效功耗进行了初步的实验研究,并提出了一种新的有效功耗计算方法,为旋转设备功耗研究和折流式旋转床工业应用提供了一定基础.折流式旋转床有效功耗可以分成两部分,即分散液体功耗和加速液体功耗.通过理论分析,得到了折流式旋转床有效功耗的计算模型.实验以水为介质,在不同液量和转速下测得有效功耗.结果表明,转速一定时,有效功耗随着液量的增加近似呈线性增加,且转速越大,有效功耗随液量增加越快.通过对实验数据的回归,得到单个同心圈转子有效功耗的计算模型,实验值与回归计算值相对偏差基本在20%以内.通过对包含4个同心圈转子的折流式旋转床有效功耗的验证结果可知,4个动圈有效功耗计算值的总和比实验测量值高20%左右,对折流式旋转床的工程放大有一定意义. 相似文献
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As a high gravity (HIGEE) unit, the rotating packed bed (RPB) uses centrifugal force to intensify mass transfer. Zigzag rotating bed (RZB) is a new type of HIGEE unit. The rotor of RZB consists of stationary discs and rotating discs, forming zigzag channels for liquid-gas flow and mass transfer. As in RPBs, some hydrodynamic behavior in RZB is interesting but no satisfactory explanation. In this study, the experiments were carried on in a RZB unit with a rotor of 600 mm in diameter using air-water system. The gas pressure drop and power consumption were measured with two types of rotating baffle for RZB rotors, one with perforations and another with shutter openings. The circumferential velocities of gas were measured with a five-hole Pitot probe. The pressure drop decreased rapidly when the liquid was introduced to the rotor, because the circumferential velocity of the liquid droplets was lower than that of the gas, reducing the circumferential velocity of gas and the centrifugal pressure drop. The power consumption decreased first when the gas entered the RZB rotor, because the gas with higher circumferential velocity facilitates the rotation of baffles. 相似文献
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通过合理简化旋转填料床(RPB)结构,建立了三维物理模型,利用商用软件Fluent的计算平台,采用欧拉两相流模型和多孔介质模型对旋转填料床内的气液两相流场进行了仿真分析,深入分析了其压力场分布和速度场分布,并在此基础上对比了气相压降随旋转床转速变化的仿真结果与实验结果,两者变化趋势一致,表明所建立模型能近似地模拟旋转填料床的流场分布,并指导理论研究和实验研究进一步深入。 相似文献
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将折流式旋转床分成若干液体流动区,计算流动区内动、静圈壁上液膜及动、静圈之间液滴的运动时间,在此基础上建立折流式旋转床持液量模型. 以空气-水为物系,在直径300 mm、高51 mm的折流式旋转床中进行实验,分别测得不通和通空气时转子的持液量,用实验数据拟合出持液量模型参数. 结果表明,转子持液量随液量和气量增加而增加,随转子转速增加而减小,高转速下气量对持液量的影响明显减弱. 折流式旋转床不通气持液量为2.35%~3.68%,是普通丝网旋转填料床不通气持液量的1.32~2.06倍. 相似文献
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折流式旋转床是一种新型的超重力旋转床,其核心部件是动、静结合的转子,转子由安装了动圈的动盘和安装了静圈的静盘上下相互嵌套而成。本实验中使用了一个常规的折流式转子(转子Ⅰ)和一个具有较短静圈的折流式转子(转子Ⅱ),在常压下分别以乙醇-水体系和空气-水体系对两个折流式转子进行了传质性能与流体力学实验,考察了静圈对折流式旋转床的传质、压降和功耗的影响。结果表明,静圈能明显强化传质过程,与转子Ⅰ相比,转子Ⅱ理论塔板数大约降低了的50%;转子Ⅰ的传质效率随转速的增大而增大,当转子的转速从400 r/min增加到1200 r/min,转子Ⅰ的传质效率增大了约40%,而转子Ⅱ的理论塔板数变化不明显;静圈使折流式转子具有较大的压降和功耗,转子Ⅱ的压降为转子Ⅰ的20%~50%,轴功率为转子Ⅰ的60%~80%。 相似文献
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German E Cortes Garcia John van der Schaaf Anton A Kiss 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2017,92(6):1136-1156
This review paper describes the state‐of‐the‐art in the field of HiGee contactors used for gas–liquid mass transfer processes, with a special focus on distillation, and for heterogeneously catalyzed reactions. Several types of rotating beds are discussed, including single‐block rotating packed‐bed, split‐packing rotating bed, rotating zigzag bed, two‐stage counter‐current rotating packed bed, blade packing rotating packed bed, rotating bed with blade packing and baffles, counter‐flow concentric‐ring rotating bed and crossflow concentric‐baffle rotating bed. The working principles of HiGee technology, as well as the modeling, design and control aspects, and practical applications are explained and discussed. In addition, this paper addresses the advantages and disadvantages with respect to mass‐transfer performance, pressure drop, rotor complexity and suitability to perform continuous distillation and to be filled with catalyst packing for heterogeneous reactions. © 2017 Society of Chemical Industry 相似文献
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Yurii Sh. Matros 《加拿大化工杂志》1996,74(5):566-579
The main techniques of studying and designing heterogeneous catalytic processes under forced unsteady-state operation (FUSO) are discussed in this review. Topics included are: a) why FUSOs are theoretically more efficient than conventional steady-state processes?; b) how can a FUSO be devised?; c) reverse-flow operation; d) partial oxidation in a circulating fluidized bed; e) processes that could be attractive under FUSO at a commercial scale, but reasons why this has not been successfully accomplished; f) FUSO systems that have not been used on a commercial scale, such as reaction chromatography, input composition cycling, input temperature cycling, and g) what could be done to encourage use of FUSOs by industry? This review demonstrates the large amounts of data that have been collected on processes proposed for FUSO. Translating these efforts into commercial success becomes possible only when researchers understand thoroughly the fundamentals of the FUSO system they are working on. An overview of past and current research suggests that a catalytic process performed optimally under FUSO will never be less efficient than an optimal steady-state process. 相似文献
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为了寻找强化间歇萃取精馏过程的有效途径,在装填2mm×2mm三角形螺旋填料的旋转床中,以乙醇-水为实验物系,乙二醇为萃取剂,通过考察馏出液组成随时间的变化情况,产品的纯度和回收率随转速、回流比和溶剂比的变化情况,研究了旋转填料床间歇萃取精馏的性能。结果表明,旋转填料床中强大的离心力和高效填料的协同作用极大地强化了间歇萃取精馏过程,具有分离效果好、操作时间短、节能、小设备大生产能力等突出优点;存在最佳转速使产品的纯度和回收率最大;增加溶剂比和回流比均能使产品的纯度和回收率得到提高,但增加溶剂比的效果更显著。旋转填料床是强化间歇萃取精馏过程的有效途径。 相似文献
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折流式旋转床气相流场实验研究 总被引:1,自引:0,他引:1
在转子直径488mm、高104mm的折流式旋转床中采用五孔探针测量了不同转速和气量下旋转床转子内腔的三维气相流场,对测定结果进行了分析,得到了气相流场矢量图.结果表明,旋转床转子内腔的气体螺旋式上升和下降,以切向气速为主,轴向气速和径向气速均较小.根据气体角动量守恒定律,越靠近旋转床轴心切向气速越大.同时分析了气体流量和转子转速对流场的影响,并获得了转子内腔的气体总压和静压分布.依实验数据计算出,当距离旋转床轴心的半径减小16.97%、转子转速增加54.18%、气体流量增加3.11倍,气体切向速度分别增加12%~41%,58%~88%和29%~73%.由无因次气体雷诺数、无因次半径和离心加速度,得到了计算无因次切向气速的经验公式,预测与实验结果吻合较好. 相似文献
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气液传质过程广泛存在于化学工业当中。气液传质强化技术的研究, 对缩短工艺流程、缩小设备尺寸、降低投资和运行成本等具有重要的意义。以旋转床为核心装备的超重力技术, 是气液传质过程强化的有效技术之一。经过30多年的发展, 超重力过程强化技术在基础和应用研究方面都取得了长足的进展, 特别是在受混合和传递限制的过程中得到广泛应用。本文从旋转床转子结构出发, 综述了整体旋转式、双动盘式、动静结合式等转子结构的超重力旋转床气液传质强化的研究进展和理论成果, 并展望了超重力旋转床气液强化传质的发展方向。 相似文献
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乙酸甲酯水解工艺与催化剂 总被引:1,自引:0,他引:1
介绍了乙酸甲酯水解的四种工艺及所用催化剂 ,四种工艺是液体强酸的固定床工艺、树脂的固定床工艺、树脂的催化蒸馏工艺和树脂的悬浮催化蒸馏工艺 ,并对各自的优缺点进行了评述 相似文献
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超重力旋转床作为如今非常重要的过程强化设备,已被广泛应用于各种化工单元操作过程之中。超重力旋转床内部的转子作为最核心的元件,其结构已发展出很多种不同的形式。本文按照转子形式的不同将超重力旋转床分为两大类,即一体化转子旋转床和分区转子旋转床,据此详细总结并介绍了各种具有典型意义的超重力旋转床的基本结构和研究近况。通过对流体动力学、传质和能耗三方面指标的讨论与分析,指出了各种类型超重力旋转床性能上的优势和存在的缺陷,对不同分离过程的结构选型具有一定的指导意义,为未来超重力旋转床转子的结构设计与优化提供了更加广阔的思路。最后,指出了现有超重力旋转床在机械方面研究的不足以及未来从基本原理的角度出发对转子进行结构设计与优化的必要性。 相似文献