汽体混合对塔板效率的影响

在液体部分混合条件下,为考虑汽体混合对塔板效率的影响,本文提出了一个新的混合模型,并获得了计算塔板效率的数学关系式.经与其它模型的计算结果比较,相当吻合.而计算方法大为简化.     

伴有二级不可逆反应的非牛顿幂律流体薄膜流中化学吸收的研究

本文对伴有二级不可逆反应的非牛顿幂律流体降膜流中的吸收过程进行了研究,提出扩散反应方程和它的解,并得到实验验证.     

Gas Absorption with or without Chemical Reaction in a Falling Liquid Film

Model equations describing the absorption of gas in a liquid film falling down a vertical wall were solved for the case of zero, first, and second order reaction by the method of backward implicit finite difference numerical scheme. The concentration profiles thus obtained were used to evaluate absorption rates and enhancement factors for Newtonian and non-Newtonian fluids. The predicted results were compared with published literature to confirm the validity of the model. Effect of interfacial drag on gas absorption with chemical reaction was also studied. The results indicated that shear stress increases the rate of absorption in case of cocurrent flow and vice versa for countercurrent condition.     

密炼机投料顺序对混炼效果的影响

针对BB430型密炼机,通过设定9组工艺分别对特定配方进行混炼,考察混炼胶的均匀性、综合物理性能及动态加工性能。研究结果表明,9组工艺控制水平均平稳,其中胶药炭同时/110℃注油的混炼工艺条件下,终炼胶具有最优的加工性能和较好的综合物理性能。     

用于CO_2吸收的离子液体的合成、表征及吸收性能

以N-甲基咪唑和3-溴丙胺氢溴酸盐为起始原料,合成了一种含氨基的离子液体(ionic liquid,IL)——1-(1-氨基丙基)-3-甲基咪唑溴盐(简写为[NH2p-mim]Br),总产率为90.1%,溴含量为0.980 mol Br/mol IL,胺含量为0.948 mol NH2/mol IL。探讨了合成工艺,并通过1HNMR、13CNMR、IR和MS对产物结构进行了表征。吸收实验结果表明,该离子液体能够有效地吸收CO2,在40℃和106 kPa下,质量分数为45%的离子液体水溶液吸收CO2至饱和时,溶液中CO2的摩尔分数可达0.444 mol CO2/mol IL,接近理论吸收量0.5 mol CO2/mol IL;在90℃的真空状态下,吸收的CO2能够完全解吸,重复吸收实验表明,该离子液体吸收CO2的能力无明显下降。     

漏液对精馏塔板效率的影响

本文提出了存漏液存在时的二维不均匀流速分布、二维涡流扩散系数不等的板上液体浓度分布数学模型和板效率计算公式,详细讨论了不同Pe、E_(OG)、K=D_W/D_Z值下漏液对塔板效率的影响,并提出了对工程设计和生产具有指导意义的某些结论。     

单、双溢流塔板液体停留时间分布和板效率的研究

在2米半园筛板试验装置上,用多点电导连续测量和微机数据采集系统研究了单、双溢流塔板的液体停留时间分布和流动型式.得到的等平均停留时间分布图表明,单溢流塔板上液体流动型式相当复杂.在双溢流板中,中央降液管塔板的流动情况与单溢流板的前半部相似;边降液管板的液体流动则要均匀得多.本文建立了由液体等平均停留时间分布曲线计算单、双溢流塔板板效率的数学模型,并给出了关系图.最后,本文提出两种改善液体流动均匀性的新结构,实验证明它们能够明显地提高板效率.     

浅述流体力学因素对精馏塔塔板效率的影响

塔板效率在实际塔设备设计中作为一个极为重要的指标,不仅描述了塔板上的传质效果,而且也是传统平衡级理论中连接工艺变量(理论板数)与设备变量(实际塔板数)的桥梁。从气液构型、液相返混、气液不均匀分布、塔板上气体混合、漏液、雾沫夹带等方面详细剖析了影响塔板效率的各个因素,以期为各种塔板的最佳操作点提供理论依据。     

The Mai-distribution of Weeping from a Distillation Tray and Its Effect on Tray Efficiency

Experiments demonstrated that the weeping is mal-distributed and occurs mainly in a region of tray deck next to the inlet weir. The amount of weeping in this region depends on the weeping rate. On this basis, three types of weeping distribution are proposed. The effect of mal-distributed weeping on the Murphree tray efficiency is evaluated by using the three-dimensional non-equilibrium mixing pool model, where the influences of the flow pattern and the variation of Murphree point efficiency on a tray are taken into account. The calculated results reveal that the extent of Murphree tray efficiency drop depends chiefly on the degree of mal-distribution and the percentage of weeping. It is also demonstrated that in the determination of the lowest operating limit of vapor velocity, the unfavorable effect of mal-distributed weeping should be considered as an important factor and cannot be ignored.     

用纤维光学技术测定液体混合程度对筛板塔效率的影响

本研究采用纤维光学技术及以任意方式注入示踪剂、两点检测之激励-响应手段,实测了普通筛板和大孔径筛板的液相涡流扩散系数.通过对试验数据的回归分析,在较宽的操作条件范围内,得到了涡流扩散系数与堰高、液流强度及空塔气体动能因子的关联式,并发现普通筛板和大孔径筛板可用同一关联式很好地关联.本文关联式所预测的板效率与实测的板效率相比相当符合.     

塔板不均匀漏液的规律及对板效率的影响

Experiments demonstrated that the weeping is mal-distributed and occurs mainly in a region of tray deck next to the inlet weir. The amount of weeping in this region depends on the weeping rate. On this basis, three types of weeping distribution are proposed. The effect of real-distributed weeping on the Murphree tray efficiency is evaluated by using the three-dimensional non-equilibrium mixing pool model, where the influences of the flow pattern and the variation of Murphree point efficiency on a tray are taken into account. The calculated results reveal that the extent of Murphree tray efficiency drop depends chiefly on the degree of mal-distribution and the percentage of weeping. It is also demonstrated that in the determination of the lowest operating limit of vapor velocity, the unfavorable effect of real-distributed weeping should be considered as an important factor and cannot be ignored.     

Comparison of Concentration Profiles for Boundary Layers in Absorption with Chemical Reaction Processes

An analysis of five different systems of absorption‐with‐chemical‐reaction in gas‐liquid reactors, commonly encountered in various industrial processes, is presented. To analyze the interphase mass transfer from gas to liquid, the rate limiting parameters and the concentrations at the gas‐liquid interface were determined on the basis of pertinent theories. The calculations presented, are based on the Whitman theory for gas and liquid phase mass transfer coefficients and Henry equilibrium constants. The necessary diffusion coefficients were calculated from existing correlations, and the corresponding chemical reaction rate constants were obtained from the literature, assuming pseudo first order chemical reaction. The process parameters required (pressure, temperature, and the gas‐liquid contact time) were within the values that occur in industrial processes. The results presented, are the concentration profiles in the boundary layers for the systems studied, calculated and graphically presented, together with the gas and liquid film thicknesses and Hatta numbers, obtained from calculations for the liquid phase mass transfer. The results may contribute to a better understanding of the absorption‐with‐chemical‐reaction processes in industrial plants, thus lowering the operational costs of these processes and alleviating the ecological problems of existing technologies.     

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%.     

大型塔板的模拟与板效率的研究(Ⅰ)——不均匀速度场的涡流扩散模型

本文介绍了直径为2m的半圆筛板塔试验装置,并得出塔板上液体流动型式和速度分布的一些实验数据。结果表明塔板上存在着相当复杂的流动和分区。 根据实验结果,在本文描述流动的微分方程中,引入了速度分布函数,并成功地用有限元素法来求解传质问题,从而得出了在不均匀的速度场下大型塔板上的液相浓度分布以及塔板效率。     

Enhancement Factor for Gas Absorption in a Finite Liquid Layer. Part 4: Influence of Gas‐Phase Mass Transfer during a Second‐Order Reaction in a Liquid in Laminar Flow

Numerical analysis is presented for gas absorption accompanied by a second‐order reaction into a liquid layer of finite thickness in laminar flow, with the gas‐phase mass transfer resistance and the axial decrease of the gas‐phase solute concentration due to absorption being taken into account. Both cocurrent and countercurrent flow modes are analyzed, where the presence of significant resistance or axial decrease of the solute concentration in the gas phase can lead to substantially lower rates of gas absorption than those found when the influence of gas‐phase mass transfer is not considered. Approximate expressions describing the exact numerical solution to the enhancement factor in the cocurrent flow mode are developed and can be extrapolated for estimating the enhancement factor in a more general case of a (1, n)‐th‐order reaction in which the influence of gas‐phase mass transfer cannot be neglected.     

Enrichment Factor,Height of Separation Unit,and Separation Efficiency by Ion Exchange with Chemical Reaction

Abstract

The enrichment factor (?_u) in the separation unit of ion-exchange and chemical reactions is a function of the enrichment factor of the chemical reaction (?_r,s) and the “equilibrium coefficients” (ζ) which are determined only by the distribution of the ions in both the solution and ion-exchange phases. The factor can be simply expressed as ?_u = ζ?_r,s. The height of the separation unit is the sum of heights due to ion exchange, chemical reaction, and flow pattern. The height is also due to the “kinetics coefficient” (ζ), which is a function of the distribution as well as the “equilibrium coefficient.” The separation efficiency is proportional to ζ/√υ, both of which depend on the concentration of ions in the unit. Several schemes for the separation units are also discussed.     

反应级数对理想反应器组合方式效率的研究

对于不同级数的不可逆反应,研究了其在全混流反应器(CSTR)与平推流反应器(PFR)不同组合方式中的最终转化率。对两种理想流动反应器的不同组合方式,如CSTR+PFR串联、PFR+CSTR串联及CSTR与PFR并联,反应的最终转化率随反应级数的不同而变化。当反应级数为负值时,CSTR与PFR并联组合方式的最终转化率最高;当反应级数为0~1之间的数值时,CSTR+PFR串联组合方式的最终转化率最高;而当反应级数大于1时,PFR+CSTR串联组合方式的最终转化率最高;当反应级数为0时,三种组合方式具有相同的最终转化率;但当反应为一级不可逆反应时,两种反应器串联时的最终转化率相同,并高于两种反应器并联时的最终转化率。     

紫外光源对炼胶烟气处理效率的影响分析

使用ICEM CFD软件建立光催化氧化设备工作腔体模型并划分网格,导入Ansys Fluent软件Do辐照模型,分析紫外光源（紫外灯管）对炼胶烟气处理效率的影响。结果表明：紫外灯管排列形式会影响工作腔体中辐照强度分布均匀性,从而对炼胶烟气处理效率产生影响;与紫外光源采用正方形排列时相比,紫外灯管采用菱形排列时工作腔体中辐照强度更大及其分布均匀性更好,对炼胶烟气的处理效率更高。该仿真结果可为橡胶厂炼胶烟气光催化氧化设备的设计提供参考。     

微波辐射对淀粉化学变性反应的影响

传统化学变性淀粉主要是在常规加热条件下通过化学反应进行合成,普遍存在着反应时间长、产率低、能耗高等问题,而微波辐射技术可使淀粉的化学变性反应进行得快速、高效、节能和环保。文章简要阐述了微波促进淀粉化学变性反应机理,分析了微波辐射技术对不同类型化学变性淀粉合成反应影响,指出微波作为绿色合成技术在化学变性淀粉合成中具有重要的应用前景。