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1.
扩散控制下固定床电化学反应器研究:(I)理论研究   总被引:9,自引:1,他引:8  
建立了固定床电化学反应器在扩散控制下的反应器模型,并对模型的简化进行了探讨,从理论上研究了床层几何尺寸、填充材料比表面积、电解液相有效电导率、反应物进口浓度、电解液流速对床层内电势分布的影响。  相似文献   

2.
发泡金属电极的宏观反应速率及电势分布   总被引:4,自引:0,他引:4       下载免费PDF全文
研究了发泡金属电极的性质 ,得出了描述发泡金属电极床层中宏观反应速率、反应速率随时间的变化、床层中电解液的电势分布方程式 .以K3Fe(CN) 6的阴极还原反应为研究体系 ,采用垂直型隔膜电解槽对上述方程进行了实验验证 ,测定了发泡镍、发泡铜作阴极时床层中电解液的电势分布 ,研究了电解质进口浓度、电解液流速、电解液有效电导率、槽电压、电极尺寸等因素对电解液电势分布的影响 ,模型结果与实验结果符合较好  相似文献   

3.
分析了两种窄筛分D类颗粒在不同喷动-流化操作条件下的床层行为特征及床层总气流阻力,研究了平底型三维喷动-流化床内的气体流动模式,从而导出在固定床阶段床层总气流阻力的表达式,得出喷动-流化操作具有优越性的结论。  相似文献   

4.
扩散控制下固定床电化学反应器研究:(Ⅱ)实验研究   总被引:4,自引:1,他引:3  
通过实验测定了扩散控制条件下固定床电化学反应器床层内的电势分布,实验结果同电势分布的计算结果吻合,从而通过实验验证了本文(Ⅰ)所建立的电势分布模型的正确性。  相似文献   

5.
径向流固定床反应器的操作状态和反应效果在很大程度上取决于反应器内穿越催化剂床层径向气流沿反应器轴向分布的均匀程度,亦即床层内催化剂负荷的均布程度。本文对此类反应器内的流动特性进行了研究,对立了描述反应器内流动规律的基本运动方程。研究结果表明,径向气流的轴向分布情况与反应器的流动结构型式、反应器内分流流道与合流流道截面积的比值、催化剂床层的阻力系数以及反应器的高径比等参数有关。并提出了如何合理选择反  相似文献   

6.
热管技术应用于化学反应器。具有高效传热、展平床层温度、控制床层温度等优点。本文详细介绍了整体热管式、分离热管式、热管翅式、密闭腔式等多种热管技术及型式在化学反应器中的研究及应用情况。  相似文献   

7.
萧任坚 《中氮肥》1994,(2):7-11
铜催化剂甲醇合成反应器床层温度接近等温分布有利于催化剂寿命长、产率高、操作稳定和产品质量好。本文介绍了冷管型甲醇合成反应器床层温度分布现状,并探讨了适应铜催化剂特点的冷管传热方式。  相似文献   

8.
许文林  刘河洲 《化工学报》1993,44(4):383-388
建立了测定固定床电化学反应器床层内电势分布的实验装置,由计算机采样测定了床层内的电势分布,并将实验结果与文献中的模型计算结果进行了比较,证明了文献所建立的反应器模型和模型方程求解方法的正确性.在不同操作模式下用实验方法考察了各因素对床层内电势分布的影响.  相似文献   

9.
滴流床反应器流体力学的研究进展   总被引:3,自引:0,他引:3  
系统综述了滴流床反应器的流体力学研究现状,分析了流型的转变、床层压降和持液量的关联结果,总结了主要的反应器模型和压力对床层压降及持液量的影响,并详细讨论了操作方式对滴流床反应器流体力学的影响。  相似文献   

10.
国内外振动流化床流体力学的研究由于实验条件的限制,其结果尚存在着分歧,在此情况下,本文在内径为148mm的振动流化床下,研究Geldar‘sA,B,C类物料起始流化时的床层压降,分别研究了颗粒物性与振动特性对床压降的影响,并且根据上述因素的影响,关联了起始流化时床层压降的计算式,并与画外学者的关联式进行了比较。  相似文献   

11.
A numerical procedure which allows the calculation of the position of the gas-liquid interface during the drainage of a two-dimensional packed bed is described. The calculations are compared with drainage experiments conducted on a laboratory scale packed bed and the agreement between the two results is shown to be excellent.The residual volume of liquid which remains undrained when the gas-liquid interface first reaches the drain point increases with increasing drainage rate and decreasing hydraulic conductivity of the bed.Computational difficulties which can arise at very high and very low drainage rates are discussed and a smoothing procedure which overcomes this problem is described.  相似文献   

12.
探讨填料层中停滞空间的起因,测定停滞空间与气、液流率以及持液量的关系。讨论了它的变化与填料层液泛的关系,提出了用停滞空间率的极大点定义泛点的新观点。  相似文献   

13.
Experiments were conducted to study the hydrodynamic behavior of the constrained inverse gas-liquid-solid fluidized bed and the semifluidized bed where the liquid is the continuous phase. Also included in the experiments was a study of the hydrodynamic behavior of countercurrent flow of gas and liquid in a packed bed. This part of the study simulates the packed section of a constrained inverse semifluidized bed. A mathematical model is developed to account for the friction factor between the liquid and solid in the packed bed. The gas hold-up and friction factor of the packed bed are analyzed and empirically correlated.Wallis' drift flux model is modified to describe the gas hold-up in a constrained inverse fluidized bed. For the constrained inverse semifluidized bed,  相似文献   

14.
旋转填充床中SO2与O2同时吸收的扩散-反应模型   总被引:3,自引:1,他引:2       下载免费PDF全文
引 言迄今为止 ,旋转填充床 (RatatingPackedBed ,RPB)用于模拟烟气的脱硫吸收 (包括物理吸收和化学吸收 )已经有了较多的研究 ,RPB中SO2 物理吸收的传质模型已有报道[1~ 3] ,但有关化学吸收的数学模型还属鲜见 .在数学上描述RPB中SO2 化学吸收的传质 -反应特征 ,必须考虑物质传递和化学反应两个方面的影响因素以及这两种因素间的相互关系 .描述气 -液相之间的物质传递过程有不同的传质模型[4 ,5] ,如双膜理论、Higbie渗透理论、Danckwerts表面更新理论和湍流传质理论等 ,但用之于处理具体…  相似文献   

15.
旋转填充床中SO2与O2同时吸收的扩散-反应模型   总被引:2,自引:0,他引:2       下载免费PDF全文
张心亚  吴元欣  李定或 《化工学报》2001,52(11):1021-1025
In this paper the rotating packed bed, a new type of absorber, which has high mass-transfer characteristic by means of centrifugal field instead of gravity field, is used to study on stimulated flue gas desulfurization. Based on experimental data,a model of mass-transfer and reaction of the sulfur dioxide chemical absorption in the rotating packed bed reactor is proposed according to the film-theory. It can be used to predict the performance of the total absorption rate and the enhancement factor of the sulfur dioxide and oxygen simultaneous absorption in the rotating packed bed reactor.The prediction of the model is consistent with the experimental result varying operating conditions, and the relative error between experimental result and predicted result is below 12%. Some interesting potential projects of simultaneous absorption of sulfur dioxide and oxygen in the rotating packed bed reactor are also discussed.
  相似文献   

16.
The relative merits of the moving packed bed, fluidized bed, and stirred bed reactors for solid-state polycondensation are discussed along with methods for improving these designs. A general model to describe continuous solid-state polymerization reactors is then developed and illustrated by a case study of a moving packed bed reactor showing the relative importance of operating variables. The model also predicts the dynamic behavior in response to several process inputs. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1775–1788, 1998  相似文献   

17.
结构化金属填充床传递特性的数值模拟   总被引:1,自引:1,他引:0       下载免费PDF全文
梅红  李成岳  刘辉  张建文  季生福 《化工学报》2005,56(7):1175-1180
运用计算流体力学(CFD)与计算传热(CHT)方法,对结构化金属填充床内的流体动力学和传热特性进行了详细的模拟,以预测其流场和温度场.分析了床层结构参数和物性的变化对结构化金属填充床传热性能的影响,发现在Re较小且结构化材料和床层空隙率相同的情况下,气固相之间换热的比表面积越大,传热效果越好.进一步将模拟结果与传统颗粒填充床的压降与传热特性进行对照,从而推断结构化金属填充床具有很好的传递性能.  相似文献   

18.
The hold-up of fine particles in the packed bed of dense particles in the multisolid pneumatic transport bed was experimentally examined. In the experiments, three types of fine particles were used including FCC particles (65 μm), glass beads (105 μm) and fine sand (155 μm), while three types of dense particles were used including aluminum particles (5.50 mm and 6.96 mm) and iron oxide particles (11.08 mm). The hold-up of fine particles in the packed bed of dense particles was found to be higher by a factor as large as 6 compared with that observed in systems without dense particles. An interaction coefficient between fine particles and dense particles was defined based on the momentum balance equation of fine particles in the packed bed. This interaction coefficient, which is empirically correlated, was utilized to account for the hold-up of fine particles in the packed bed.  相似文献   

19.
The removal of copper ions was studied experimentally in a semifluidized bed charged with a strong cation-exchange resin, Amberlite 200C. The semifluidized bed system was formed by inserting a retaining grid in a packed bed and increasing the fluid velocity above Umf. In this arrangement, the bed is separated into two sections; the upper packed bed section and the lower fluidized bed section. As the fluid velocity increases, the portion of the packed bed section becomes larger. As expected, the breakthrough curve obtained from the semifluidized bed lies between those from packed and fluidized beds. The breakthrough curves of copper ions were predicted reasonably well by using an axial dispersion model. In this paper, the effects of the liquid flowrate and the retaining grid height on the breakthrough behavior are extensively discussed.  相似文献   

20.
Modeling and simulation based on computational hydrodynamics and heat transfer for metal structured packed bed are carried out to predict the flow field and temperature field, and to evaluate its performance in transport aspect. The comparison between the simulation results for the metal structured packed bed and the experimental heat transfer performance as well as pressure drop of the conventional pellet packed bed is made, which quantitatively validates that transport performance of the metal structured packed bed is much better. Furthermore, the effects of geometric parameters and the property of solid phase on heat transfer of the metal structured packed bed are discussed. It is found that at low Re, the specific surface area is a key factor to determine the heat transfer capability of the structured bed. However, when Re turns to be high, the property of solid phase and voidage of the structured packed bed will play an important role in the evaluation of its heat transfer. In light of above results, some feasible methods are available to enhance the heat transfer performance.  相似文献   

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