场流分离理论的研究现状及发展趋势

原文摘录：场流分离是一种方便快捷的分析分离技术，它具有设备简单，应用广泛，效率高等优点。本文介绍了场流分离原理及理论，描述了场流分离设备的主要结构，着重讲述了电场流分离、热场流分离、沉降场分离、流场流分离的方法及应用。比较了不同场流分离技术的差异，展望了场流分离发展的方向。     

煤焦油萃取分离实验研究

煤焦油中含有上万种有机化合物，化学组成复杂，分离困难，一般分离效果也差。本文在实验室实验的条件下，采用溶剂革取分离煤焦油，实现了较好的初步分离，回收率达到了95%以上，并确定了分离的最佳条件。     

日东丽开发对二甲苯用沸石膜分离工艺

对二甲苯主要从催化重整得到的二甲苯混合物中分离制得，分离后残液中的对二甲苯仍可循环利用。对二甲苯分离过程可利用对二甲苯与其异构体之间的凝固点的差异用深冷法分离。二甲苯三个异构体的尺寸为：对二甲苯5．9A，间二甲苯6．8A，邻二甲苯6．8A，也可用分子筛筛分分离，所以日本东丽公司研究了具有选择渗透性能的沸石分离膜，并用于二甲苯分离过程中，以提高对二甲苯产量。     

聚结分离技术在环己烷氧化装置的应用

废碱液的分离是环己烷氧化法制环己酮工艺的一项难题，一旦废碱液分离不彻底，将导致烷塔系统带碱，致使醇酮缩合、换热器结垢，使生产消耗增加、开车周期缩短。聚结分离技术是一项新型的分离技术，多用于航空行业油水分离。本文主要介绍通过实验研究和技术改造，有效的应用聚结分离技术解决环己烷氧化装置废碱液分离不彻底的问题。     

水力旋流器分离空间匹配优化研究

首次系统地研究了水力旋流器分离空间匹配系数对其分离性能和能量耗损等方面的影响，结果表明，随着柱锥空间比值的增大，分离修正总效率上升，能耗系数降低，分离粒度和分离精度则呈二次曲线形变化。最后给出了适应不同场合要求的水力旋流器的最佳分离空间匹配系数和圆筒段长度推荐值。     

惯性分离装置的性能分析及结构优化

通过搭建惯性分离装置测试平台，结合相关检测设备的数据采集，进行某型惯性除雾器的性能分析。实验发现，两通道折流惯性分离装置的分离效率与液滴直径成正比。对于微小粒径5～10μm的液滴分离效果不佳，风速对分离效率的影响不大。对于30μm以上的液滴分离效果较好，效率整体超过80%。系统进出口压降损失方面，粒径的变化相对于整个装置可以近似忽略，不同粒径条件下压降曲线变化基本相同，风速是压降变化的主要影响变量。为突破小粒径液滴分离效果不佳的限制，分别从板间距、底面高度及板型等方面入手，分析不同尺寸参数条件下分离效率与压降的变化规律。计算结果表明，板间距数值越大，分离效率越低，系统压降越小；底面高度与效率变化并不是总体相关，存在波动并呈现局部相关性；高度增加到30mm时达到最佳，系统压降也较小；通道级数越多，分离效率越高，但压降增加较大；流线型壁面分离效果较好，控制压降的能力也较强。     

本期推荐——苯系列化合物

苯甲酸加氢方法 本发明公开的一种苯甲酸加氢方法是将熔融苯甲酸在Pd／C催化剂和镍助剂存在下，与氢气接触反应后，采用旋液、离心和磁分离3级分离过程，将催化剂从混合物中分离并循环回反应器，其中旋液分离后的浊液循环回反应器，清液进入离心分离器，经分离后下部的催化剂循环回反应器，上部清液进行磁分离，分离出镍基助催化剂循环回反应器。该方法可有效分离镍助剂，进一步提高Pd／C的活性，具有更高的反应处理能力和生产效率。     

高沸点热敏体系精馏过程的研究进展

在精馏系统中，高沸点、热敏性物系分离存在物料受热温度高且时间长的问题，容易引起热敏性物质变质，一直是高效分离与提纯的难点。本文对高沸点热敏性物质精馏分离理论基础进行归纳，提出操作压力低和停留时间短的工艺要求。基于此，总结了分子蒸馏和真空精馏（包括真空蒸馏、真空分馏、真空间歇精馏）在高沸点热敏性物系分离中的优缺点及应用，发现分子蒸馏的真空度和分离程度较真空精馏高，但分离效率和工业化程度比真空精馏低。最后，文章指出，对于采用精馏分离高沸点热敏性体系仍需在新工艺和新设备等方面进行探索，以提高分离效率和降低分离能耗，便于实现工业规模应用。     

气体分离膜的研究进展

根据气体分离膜的过程特征，对已有的气体分离膜进行了系统综述，并对各种气体分离膜的分离性能作了阐述。     

炭-炭复合膜制备的探索研究

以煤沥青基炭分离膜为支撑体，采用聚合物溶液涂层或浸渍制备出了炭－炭复合分离膜，测试了高纯H2，CO2，N2和O2单组分在炭－炭基复合分离膜上的渗透速率，计算了各气体组分的理想分离系数。结果显示以聚乙二醇水溶液进行表面涂层制备的炭－炭复合膜，其气体分离性能与炭分离膜相比稍有提高，以酚醛树脂N，N－二甲基乙酰胺溶液和加有分散剂的酚醛树脂乙醇溶液涂层制备的炭－炭复合膜在分离性能上都有较大提高，尤其加有分散剂的酚醛树脂乙醇溶液涂层后可使H2／CO2的分离系数达16．0左右，而采用酚醛树脂乙醇溶液涂层和浸渍得到的炭－炭基复合膜的气体渗透速率和分离系数均下降。     

ICP-AES测定以硅酸盐为主的矿物中Al、Fe、Ca、Mg、K、Na、Ti、Mn等元素的方法

研究了应用电感耦合等离子体发射光谱法 ,选取适宜的仪器工作条件 ,分析硅酸盐矿样中Al、K、Na、Ca、Mg、Ti、Mn、Fe8个元素的方法。与传统方法相比 ,大大简化了操作程序和劳动强度 ,缩短了工作时间。用本法对岩石系列标准物质中 8个元素进行了分析 ,其结果与参值相符。     

Polymere in der drucktechnik

Three main processes are used in the printing industry: Letterpress, Lithography and Gravure printing. In the early fifties polymer coatings have been introduced in lithographic printing plates formulations. Later, similar systems have proved to be suitable for letterpress, and very recently for gravure printing layers, too. Most polymer formulations used in printing techniques generally have the following features in common: ? They are light sensitive ? They are coated on to a flat substrate ? After imagewise exposure the more soluble areas of the coatings are removed in a development step. The requirements for the polymers used in printing layers are as different as the characteristics of each individual printing process. ? The importance of the specific optical properties of the polymers is demonstrated discussing some negative acting light sensitive systems, amongst them the photopolymerisation of monomers.     

Multi-response optimization of mechanical properties for ZrWN films grown using grey Taguchi approach

ZrWN nitride films are prepared using direct current (dc) reactive magnetron sputtering. Grey Taguchi analysis is used to determine the effect of deposition parameters (substrate plasma etching time, N₂/(N₂+Ar) flow rates, deposition time, and substrate temperature) on the microstructure and the tribological properties. An orthogonal array, signal-to-noise ratio and analysis of variance are used to determine the effects of deposition parameters. The substrates are pretreated using oxygen plasma etching. The resulting ZrWN coatings are homogeneous, very compact and completely adhered to the substrate. In the confirmation runs, using grey Taguchi analysis, the coefficient of friction decreases from 0.45?±?0.02 to 0.35?±?0.02, the corrosion potential increases from ??0.201?±?0.01 to ??0.072?±?0.01?V, the Vickers hardness increases from 23.63?±?0.07 to 24.65?±?0.05?GPa, and reduced modulus increases from 115.82?±?1.13 to 136.17?±?1.18?GPa. The ZrWN films are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Rockwell C indentation and scratch testing. The TEM pattern for the ZrWN films corresponds to the (111), (200) and (220) planes of the face center cubic structure. Samples with a ZrWN film coating are classified as HF1 and exhibit good adhesive strength. The signal of friction and the associated acoustic emission signal are analyzed, and the scratch profile is analyzed using an optical microscope. Results show that the adhesive force for the critical load Lc2 is about 76.2?±?0.5?N.     

聚乙烯管道热熔接头可靠性评价方法研究

介绍了目前国内外聚乙烯管道熔接接头可靠性评价的短期力学性能和长期耐慢速裂纹拓展的主要检测方法及其适用性研究.近年来,超声波相控阵被广泛应用于熔接接头可靠性无损检测,其自动化检测和结果智能化判定是一个重要的研究方向.目前我国标准中对熔接接头可靠性检测的项目较少,为使聚乙烯承压管道向厚壁、大口径、高耐压、耐高温、长寿命和更...     

蛋白质塑料改性研究进展

力学性能较低和对水敏感是阻碍蛋白质基降解塑料广泛应用的不利因素,为了克服这一缺点,人们广泛探索了对蛋白质的各种改性:热、碱改性、还原剂改性、交联剂改性、添加助剂改性、填充改性、酸改性等来改善力学加工性能,以期获得具有实用价值的蛋白质塑料。     

Füllstand- und Durchflußmessung in verfahrenstechnischen Anlagen

Measurement of Level and Flow in Processing Plants The author reviews the processes and systems for the measurement of level. The devices are described for indicating the states ?Full”? and ?Empty”? in the automatic charging and discharging, for continuous measurement in the monitoring of the stores and processes, for measuring systems based on specific properties, such as conductivity and capacity, for electromechanical systems, for non-contact measuring procedures based on sonic and ultrasonic echometry as well as radioactivity, for microwave systems, and for the measurement of aggressive products and substances under high pressures and temperatures, and, in explosion-proof plants. In the measurement of flow, inductive flowmeters of high precision and reliability are used for conducting liquids; corrosion-resistant turbines are used for all products with low viscosity; tooth wheel flowmeter are used for highly viscous materials. The processes for the measurement of level and flow are described in an example for the treatment of waste water.     

两段沉淀法处理含氟尾气、废水及固废减量化技术

研究采用两段沉淀法处理含氟尾气和废水及固废减量化技术,一段沉淀以理论量95%~105%石灰乳为沉淀剂,将含氟废水中的95%以上的氟离子沉淀除去;二段沉淀以理论量150%~200%的石灰乳为沉淀剂,并用盐酸调节pH至中性,两段沉淀后的废水F-质量浓度为8~12 mg/L。该项技术具有沉淀剂用量少、沉降速度快、过滤性能好、滤饼含水率低和固废量少的优点,值得进行推广应用。     

Effect of the type of nylon chain‐end on the compatibilization of PP/PP‐GMA/nylon 6 blends

Polyamide and polypropylene (PP) are two important classes of commercial polymers; however, their direct mixing leads to incompatible blends with poor properties. Polypropylene functionalized with glycidyl methacrylate (PP‐GMA) was used as a compatibilizer in blends of PP and nylon 6, because of the possible reaction of ? NH₂ and ? COOH groups with the epoxide group of GMA. Two types of nylon 6 with different ratios between ? NH₂ and ? COOH groups were used. The one with higher concentration of ? COOH groups was less compatible with PP in a binary blend. When PP‐GMA was used as a compatibilizer, a better dispersion of nylon in the PP matrix was obtained together with better mechanical properties for both nylons used in this work. © 2001 Society of Chemical Industry     

Investigating the effect of SPS‎ parameters on densification ‎and fracture toughness of ZrB2-SiC nanocomposite‎

In this study, the effect of sintering parameters on densification and fracture toughness of spark plasma sintering ZrB₂-SiC nanocomposites was evaluated. For this purpose, ZrB₂-??30?vol% SiC nanocomposites in the conditions of ?1600?°C-4?min, 1700?°C-4?min, 1800?°C-4?min, 1800?°C-8?min, 1800?°C-12?min? were sintered.? Scanning Electron Microscopy (SEM) was used in order to investigate the ?microstructural variations. The bulk density was measured accoring to ASTM C 373–88. Single edge notch beam (SENB) method was used to ?determine the fracture toughness of samples. Microstructural observations showed that ?an increase in sintering temperature led to slight ?increase in SiC grains size but no sensitive variation in ZrB₂. However, increasing the sintering time resulted to increase both ZrB₂ and SiC grain size. Also, it was found, temperature and time ascent always increases the relative density. In addition, it was concluded that optimal temperature and time to reach the highest fracture toughness are 1800?°C and 8?min, respectively. Investigation of SEM images of the Vickers indent and their path propagation showed that the deviation and branching of crack are the most important toughening ?mechanisms in ZrB₂-SiC nanocomposites.?     

克劳斯硫回收工艺中的富氧技术

分析了富氧技术在克劳斯硫回收装置中利用的工艺限制因素，介绍了Cope、Oxyclaus、Sure、No TICE和P－Combustion等富氧技术的优、缺点及其在克劳斯装置中的工业应用，指出P－Combustion技术是一种比较有效、廉价、能提高硫回收装置能力的好方法，同时分析了装置供氧的经济性。