精馏塔负荷性能图分析技术新发展

系统介绍了按照流体力学极限和传质操作限制来构造精馏塔负荷性能图的方法.提出了适用于进料条件全面变化的可行稳定域分析方法,将塔板负荷性能图分析由一条线拓展到一个面;首次以平衡级离散填料床的方法构造了填料塔的负荷性能图;推荐以降液管入口液速作为负荷性能图的横坐标,不仅统一了塔板负荷性能图的纵、横坐标单位,也为塔板/填料混合型精馏塔实现全塔分析奠定基础.在此基础上提出了全塔负荷性能图的新分析方法,将精馏塔的分析由单层塔板、单段填料上升到全塔的范畴,进行精馏塔瓶颈分析、塔板/填料匹配设计十分容易、便利,是最简单的精馏塔瓶颈分析方法.     

基于遗传算法的板式塔负荷性能图优化设计

对板式塔设备进行负荷性能优化设计,在设计计算模块中,应用遗传算法,实现了塔设备负荷性能图的优化.     

板式塔负荷性能图的优化方法

通过对目前板式塔设计过程中负荷性能图调整方法的分析 ,提出板式塔负荷性能图调整的优化方法和优化过程。通过对目前板式塔设计过程中负荷性能图调整方法的分析 ,提出板式塔负荷性能图调整的优化方法和优化过程。     

板式塔塔板主要结构尺寸的新设计方法——负荷性能图法

通常在板式塔设计过程中，为了保证上操作弹性和下操作弹性之值，需反复调整塔板各结构尺寸。本文提出由负荷性能图中各性能曲线计算式直接确定塔板主要结构尺寸，称其为负荷性能图法。通过浮阀塔负荷性能图中各性能曲线与塔板各主要结构尺寸的简要分析，阐述了设计步骤。该法计算简单，能有效提高设计速度。     

基于CAGD的板式塔负荷系数确定方法

采用计算机辅助几何设计的方法(CAGD法),对史密斯关联图进行计算机精确描绘.利用Visual Basic和AutoCAD混合编程进行计算机准确查图,利用Visual Basic进行人机交互界面设计和前台运算,AutoCAD技术进行后台图形处理,准确确定给定条件下的板式塔负荷系数.     

表面性质对板式塔性能的影响

<正> 1 实验装置与方法 为研究表面张力梯度对不同类型塔板传质性能的影响及塔板材质的影响,本实验选择了以下四种塔板: (1)不锈钢筛孔板     

筛板式板式塔的基本原理及流体力学性能分析

本文介绍了板式塔(筛板式)的基本结构,并分析了其流体力学性能及产生原因,为解决板式塔在丙烯酰胺生产中遇到的问题,提高塔的使用效率提供了思路.     

塔板结构参数对负荷性能曲线的影响

通过对板式塔流体力学性能的分析,找出了板式塔塔板结构参数对负荷性能图中负荷性能曲线的影响关系,可用于指导板式塔的优化设计和改造。     

板式塔的设计问题

在板式塔的设计中,需要用大量的计算公式和图表才能确定设计方案。特别是塔的结构设计由于设计参数较多,求解过程复杂,使得计算工作量很大。本文以筛板塔的设计为例,重点对板式塔的结构设计问题提出一些新的计算方法,对现有的图表和公式求解的参数进行了简化,更有助于应用计算机进行辅助计算。     

关于板式塔的评介

对在化工生产中广泛使用的主要板式塔的优缺点及应用范围进行了介绍，并对如何改善板式塔的流体力学状况，提高板效率的方法和措施进行了阐述。     

全指标精馏塔全塔负荷性能图分析新方法

针对传统塔板负荷性能图在现代精馏塔分析中存在的问题,提出一种精馏塔全指标全塔负荷性能图新分析方法。与单指标的全塔负荷性能图相比,全指标全塔负荷性能图用于精馏塔瓶颈分析,不同塔内件合理匹配分析和最终施工图设计塔内件评价方面更加直观、容易、便于编程。     

Performance of combined mesh packing and sieve tray in distillation

The hydraulic and mass transfer performance of a combined knitted mesh packing and sieve tray has been measured for the distillation of methanol-water mixtures. It was found that by adding a shallow bed of packing, the Murphree tray efficiency increased by 40–50% over a wide range of concentrations and flow rates. This increase in tray efficiency can be attributed to a much smaller and more uniform bubble formation on the packed tray. Hydraulic measurements have shown that the packed trays have lower weeping and entrainment, as well as slightly higher froth heights and pressure drops.     

改进的信息流图及其在精馏塔建模与仿真中的应用

计算机动态建模与仿真中,人们最常用的用以辅助进行交流和讨论以及文档化相关成果与决策的分析、设计方法及表示法是信息流图（information flow diagram）。在前人研究的基础上,提出了一种改进的、更为完善的信息流图表示法。该表示法共包含三大类、九小类组成元素,基本能够完全覆盖计算机动态建模与仿真中所有种类的数学公式及其他模型表达方式。最后,以精馏塔的动态建模与仿真为例,详细说明了改进的信息流图的具体应用情况。事实证明,改进的信息流图不仅为相关工作人员提供了良好的沟通媒介,还使人们能够更加容易地从先前的仿真模型构建项目中复用需求和设计组件等,从而提高了仿真模型构建的效率和质量。     

Performance of packings for water distillation

Distillation of water has been investigated in packed columns of 300, 500 and 750 mm diameter. Both ordered packings (Goodloe, Mellapak and Sulzer CY) and random packings (Hy-Pak, Mini-ring and Pall-ring) were studied and performance compared. It was found that, with surface treatments, phosphor bronze packings show good performance and insignificant scale-up factors. Plastic materials are not suitable for water distillation because of their poor wetting characteristics.     

Performance and applications of flow-guided sieve trays for distillation of highly viscous mixtures

With a particular focus on the distillation of highly viscous or self-polymerized mixtures, this study reports the hydrodynamic and mass transfer performance of two flow-guided sieve trays, including their pressure drop, entrainment, weeping and tray efficiency, obtained experimentally with an air-water/oxygen system in a Φ600 mm plexiglass column. The results show that the 8 mm hole flow-guided sieve tray tested shows better characteristics than the 7 mm flow-guided hole tray in terms of pressure drop and mass transfer. Then we present practical industrial examples of applications of the flow guided trays for distillation of viscous mixtures, i.e., the separation of vinyl acetate (VAC) from a polyvinyl acetate (PVAC) polymer solution with dynamic viscosity μ=50,000 mPas, the separation of highly unsaturated C5 mixtures by extractive distillation, and the distillation of thick, condensed and highly viscous fermentation mixtures made from fermented mash. It is demonstrated that flow-guided sieve trays with relatively large holes are an excellent candidate for distillation of mixtures with suspended solids, or concentrated/self-polymerized polymer solutions.     

热耦蒸馏及其选用原则

热耦蒸馏与常规蒸馏序列相比可减少能耗和设备投资,但其应用有一定的适用范围。文章通过严格模拟计算研究了热耦蒸馏适用范围,结果表明:该蒸馏技术主要适用于分离指数接近1的混合物,或分离指数小于1但中间组分含量较高的混合物。     

Methodology for design and analysis of reactive distillation involving multielement systems

A new methodology for design and analysis of reactive distillation has been developed. In this work, the element-based approach, coupled with a driving force diagram, has been extended and applied to the design of a reactive distillation column involving multielement (multicomponent) systems. The transformation of ordinary systems to element-based ones and the aggregation of non-key elements allow the important design parameters, such as the number of stages, feed stage and minimum reflux ratio, to be determined by using simple diagrams similar to those regularly employed for non-reactive systems consisting of two components. Based on this methodology, an optimal design configuration is identified using the equivalent binary-element-driving force diagram. Two case studies of methyl acetate (MeOAc) synthesis and methyl-tert-butyl ether (MTBE) synthesis have been considered to demonstrate the successful applications of the methodology. Moreover, energy requirements for various column configurations corresponding to different feed locations are determined to verify whether the optimal design can be identified by following the proposed methodology.     

A novel type of equipment for reactive distillation: Model development,simulation, sensitivity and error analysis

A simulation study of heterogeneously catalyzed reactive distillation experiments carried out with the D + R tray, a novel type of laboratory equipment, is presented. One advantage of the D + R tray is that reaction and distillation are alternating stage‐wise, in a well‐defined way that can be modeled straightforwardly. An equilibrium stage model is used to describe the distillation and a plug flow reactor model to describe the catalyst bed reactors. The model parameters are derived from a systematic experimental characterization of the D + R tray both as a reactor and as a distillation unit. A validated physicochemical fluid property model is used. The primary experimental data are reconciled. Results from the predictive simulations are in good agreement with the experimental results. The influence of errors in the input parameters on the simulation results is investigated by means of a sensitivity and error analysis. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1533–1543, 2013     

10t/d船用板式蒸馏海水淡化装置性能测试与模拟计算

建立了一套船用板式蒸馏海水淡化装置试验测试平台,对10 t/d淡化装置进行了性能测试,在测试所采用的海水及热水流量下,热水温度由59℃升高至83.77℃,淡水产量由400 L/h提高至550 L/h,进一步提高热水温度,淡水产量提高趋于平缓,操作时热水温度不宜超过85℃;随热水流量的增大,淡水产量呈现先升高后降低趋势;海水入口温度升高造成冷凝器中传热温差降低,真空度降低,产水量下降;海水流量是制约海水淡化装置真空度的关键因素,作为真空喷射泵的驱动水,当海水流量低于一定值时,淡化机真空度急剧下降,几乎不能出水。对板式蒸馏海水淡化装置进行了理论模拟,模拟结果与试验测试数据吻合良好。     

Comparison between the design of experiments and simulation in the three-phase distillation in a sieve tray column for glycerine dehydration

Design of experiments (DOE) is a value scientific approach used to understand the processes in a better way and to determine how the inputs affect the response(s). In this work, this method has been applied to study the behavior of the three-phase distillation in a sieve tray column, through the effects of the process and geometrical variables. The experimental values were compared with predicted values obtained by simulation using the equilibrium and nonequilibrium models. Three-phase distillation has been used for glycerine dehydration using toluene as entrainer, in order to avoid the glycerol degradation by distillation at atmospheric pressure. The best conditions found were: vapor flow rate of toluene = 23.5 kg/h, feed flow rate = 2.2 kg/h and feed concentration = 50 wt% glycerol, using the layout L₄ with fractional hole area = 0.04 and weir height = 70 mm. The nonequilibrium model based on Eckert and Vanek's approach (2001) and Chen–Chuang's correlation (1993) have been used to estimate the binary coefficients of mass transport. The predicted values obtained by the experimental model and by the nonequilibrium model have represented the behavior of the dehydration in the sieve tray column studied. Both models underpinned the experimental results obtained for this column.