Rührkessel-Reaktoren für Polymer-Synthesen

Stirred tank reactors for polymerization . A general survey on stirred tank reactors and cascades of stirred tanks in industrial polymerization (bulk, solution, precipitation, grain and emulsion polymerization) is presented. Special consideration is given to the various designs of both agitator and cooling devices. Scale-up problems arising from the multitude of process functions (homogenisation, suspension, dispersion, promotion of heat transfer) carried out in a stirred vessel are explained and the divers methods of indirect cooling (jacketed tank, internal coil, external heat exchanger) as compared to evaporative cooling are assessed. Finally, safety measures in operating polymerization vessels are discussed.     

合成氨装置低压蒸汽发生器的设计

介绍合成氨装置低压蒸汽发生器的设备结构、选材、结构设计及制造检验等设计思路和方法,分析探讨管程堆焊结构、焊接方式及焊环式密封结构的设计,为合成氨装置中高温高压容器设计总结出一套可行的方法。     

Partikelgrößenanalysen < 10 μm Meßmethoden und Schwierigkeiten

Particle size analysis of particles < 10 μm – methods and difficulties . A review of possible methods for the determination of particle size distributions in the range < 10 μm is presented. Important factors regarding the specimen dispersion are dealt with, particularly those which must be taken into consideration in the “fines” region, and the limits and difficulties of individual analytical equipment are illustrated with the aid of examples. Finally, analytical results obtained by various methods of measurement are compared and the criteria of assessment such as operational possibility and costing are discussed.     

Prüfmethoden für Kunststoffbehälter in der chemischen Industrie

Methods of testing plastic vessels in the chemical industry . Methods are discussed for the testing of vessels made of thermoplastics and glass fibre reinforced plastics. Technical notes, guidelines and standards (DVS, VDI, DIN) describe methods of ensuring the quality of new containers. New testing methods have to be employed for equipment that has long been in use in order to provide subsequent confirmation of suitability. An appropriate concept is presented.     

吸收法试剂硫酸生产装置大型化探讨

详述吸收法试剂硫酸生产的工艺原理和几种常用工艺流程,主要有抽气式过滤净化吸收法、全气式过滤净化吸收法及发烟净化吸收法工艺流程。对3种工艺流程中主要生产设备的材质和制造工艺进行了简单探讨,并介绍了生产中常见问题及解决对策。     

Lagern und Umschlagen von Schüttgütern in der Chemischen Industrie

Storage and trans-shipment of bulk solids in the chemical industry. Theoretical fundamentals of the motion of bulk solids in bunkers were considered in detail at the Annual Meeting of Chemical Engineers held at Karlsruhe in 1975 [1]. The present account will deal exclusively with practical aspects playing a role in the building and operation of storage and trans-shipment facilities for bulk solids. Various problems encountered are illustrated for some typical bin storage units in the chemical industry. Moreover criteria are mentioned which can assist the design engineer in the correct choice of silo type and suitable materials of construction, and the ascertainment of the right size of silo. Filling and emptying devices are also proposed for differing spatial circumstances and various tasks. Important ancillary equipment such as ladders, platforms, and devices for monitoring filling levels are also treated. A consideration of the principal regulations governing the operation of silo systems is followed by some hints on the transport, erection, and assembly of silos.     

通过优化设计及工艺控制提高火管废热锅炉制造质量

针对硫磺制酸装置火管废热锅炉的特点,论述优化设计和工艺控制方法。详细介绍了所执行的各种设计标准、设备结构和施工方法。建议严格遵守压力容器标准、规范和施工工艺,以提高废热锅炉制造质量,保证硫磺制酸装置安全、稳定、高效运行。     

Systeme zum Ein- oder Austrag von Schüttgütern in oder aus Druckräumen

Systems for the charging or discharging of bulk solids into or out of pressure chambers. In many branches of chemical and dressing technology there are compelling thermodynamic or economic reasons for carrying out various processes at pressures deviating from ambient values. If the reactants and products of these processes are dusts or granular solids then numerous problems are encountered on transfer between regions of higher or lower pressure. On the one hand, the properties of the feed (such as particle size, flow behaviour) should undergo the slightest possible modification, and on the other hand the transport of the material between the regions of differing pressure should be as continuous as possible. Moreover, the gas transport should be kept low. Pressure swing in the process region is to be avoided. The aim of this study was to survey all systems suitable for introduction or removal of bulk solids into or out of chambers at pressures other than the ambient value. The various pressure locks are assessed qualitatively for given tasks. A new solution is presented for the discharge of filter cake from high-pressure chambers.     

低温储罐的设计改进

在设计条件一定的前提下,根据压力容器设计规范的有关规定,在保障压力容器安全运行的条件下,选择一种最佳设计方案,以降低设备制造成本,获得最佳的经济效益.本文就16MnDR材料的二氧化碳低温储罐是否需进行焊后热处理的条件进行了分析和论述,科学合理地提出了设计改进的措施.     

尖晶石型Li_4Ti_5O_(12)锂离子电池负极材料研究现状

尖晶石型Li4Ti5O12因其在循环过程中具有良好的稳定性和安全性以及优良的快速充电性能,成为锂离子二次电池负极材料研究的热点。较完备的介绍了锂离子电池负极材料尖晶石型Li4Ti5O12的国内外研究制备方法,通过比较,详细描述了各方法存在问题及优缺点,给出了相应问题的解决方案,同时对尖晶石型Li4Ti5O12作为锂离子动力电池负极材料的发展趋势进行了展望,使用Li4Ti5O12负极材料的电池最有可能作为HEV动力电池率先得到应用。     

纳米级TiO_2堆积密度对脱硝催化剂生产的影响

纳米级TiO_2广泛应用于脱硝催化剂生产领域,堆积密度指标常被忽视,在生产中出现混料不均、下料不畅和堵塞设备等现象。通过对设备、工艺指标和原料等分析,最终确定引起此问题的原因为原料纳米级TiO_2堆积密度的变化。针对设备具体情况将纳米级TiO_2堆积密度指标控制在合适范围,通过调整设备参数等方法,较好地解决生产堵塞问题。     

Dichtstromförderung

High density pneumatic conveying . In distinguishing between high density pneumatic conveying and low density conveying it is insufficient to merely use the solids loading to characterize the various flow states. Less ambiguous classification is possible only on the basis of the diagram of state of pneumatic conveying. Most flowable bulk solids can be transported through normal smooth-walled piping in the high density mode with normal conveying equipment. In contrast, fine-grained products in particular tend to adhere to the wall and form blockages. Paying due attention to the differing flow properties of various bulk solids and to the mechanisms of blockage formation and clearance, various new conveying techniques and piping types have been developed in recent years, permitting in some cases the transport of adhering, abrasive, and attrition-sensitive materials. Since conveying pressures up to about 6 bar are usual in the high-density regime, various combinations of pressure vessels are primarily used for feeding the bulk solids into the conveying pipes. The advantages of conventional, and also special high-density conveying systems are discussed with the aid of examples.     

尖晶石型Li4Ti5O12锂离子电池负极材料研究现状

尖晶石型Li4Ti5O12因其在循环过程中具有良好的稳定性和安全性以及优良的快速充电性能,成为锂离子二次电池负极材料研究的热点。较完备的介绍了锂离子电池负极材料尖晶石型Li4Ti5O12的国内外研究制备方法,通过比较,详细描述了各方法存在问题及优缺点,给出了相应问题的解决方案,同时对尖晶石型Li4Ti5O12作为锂离子动力电池负极材料的发展趋势进行了展望,使用Li4Ti5O12负极材料的电池最有可能作为HEV动力电池率先得到应用。     

Dynamic Charging Performance of a Solar Latent Heat Storage Unit for Efficient Energy Utilization

The dynamic charging performance of a solar heat storage system involving a packed bed containing spherical capsules is studied. The dynamic charging process of the solar heat storage system is simulated according to the energy balance equations. Paraffin is used as the phase change material (PCM) and water is used as the heat transfer fluid (HTF). The temperatures of the PCM and HTF, melting fraction and solar heat storage capacity are illustrated and analyzed. The influences of inlet temperature, initial temperature and flow rate of HTF, and the porosity of the packed bed on the charging time and heat storage capacity during the heat storage process are also discussed.     

关于冲击试验的试验温度和冲击吸收功合格指标问题

简要介绍在不同设计温度的钢制压力容器材料、焊接工艺评定和产品焊接试板力学性能检验中,冲击试验的试验温度和冲击吸收功合格指标的确定方法,结合典型问题,用标准规定进行分析、解释。     

Advances in Lipid Extraction Methods—A Review

Extraction of lipids from biological tissues is a crucial step in lipid analysis. The selection of appropriate solvent is the most critical factor in the efficient extraction of lipids. A mixture of polar (to disrupt the protein-lipid complexes) and nonpolar (to dissolve the neutral lipids) solvents are precisely selected to extract lipids efficiently. In addition, the disintegration of complex and rigid cell-wall of plants, fungi, and microalgal cells by various mechanical, chemical, and enzymatic treatments facilitate the solvent penetration and extraction of lipids. This review discusses the chloroform/methanol-based classical lipid extraction methods and modern modifications of these methods in terms of using healthy and environmentally safe solvents and rapid single-step extraction. At the same time, some adaptations were made to recover the specific lipids. In addition, the high throughput lipid extraction methodologies used for liquid chromatography-mass spectrometry (LC-MS)-based plant and animal lipidomics were discussed. The advantages and disadvantages of various pretreatments and extraction methods were also illustrated. Moreover, the emerging green solvents-based lipid extraction method, including supercritical CO₂ extraction (SCE), is also discussed.     

Die Anwendung von Prozeßrechnern in der Waschmittelproduktion

The Use of Process Control Computers in the Production of Laundry Detergents Modern laundry detergent production plants require highly sophisticated measuring and controlling systems in order to maintain high and even quality of the products. In addition, the detergent industry is under a very high cost pressure due to market circumstances. It appeared to be efficient to improve the measuring and controlling technology by using process control computers and to come to production methods with lower cost rates. Also, even and safe operation methods are desirable for every production process as well as rapid recognizing and elimination of troubles and early warnings in case of breakdowns. Prerequisites with regard to computer control are a high level of the process equipment and a continuous recording of measuring data, which is very important. The method of operation of the computer control is discussed in general the resulting efficiency is presented. The efficacy can be quantitated with regard to the desired decrease of raw material costs, conservation of energy and saving manpower. The efficiency can not be quantitated with regard to deepening of knowledge of the process, accelerating of the performance of trials, collecting experience for other processes and as prerequisite for a composite system of electronic data processing in the production department.     

废旧塑料摩擦荷电机理及摩擦电选技术研究进展

塑料由于材质轻、化学性质稳定、成本低、耐磨性及耐腐蚀性好等优点被广泛应用于工程建设、食品安全、交通运输以及医疗等领域,如果处理不当会对环境造成严重的污染,废塑料污染防治已成为全球关注的环境问题。目前处理废旧塑料的常用方法有风选法、浮选法、静电分离法和光选法等,摩擦电选作为一种新型干式分选方法越来越受到研究者们的重视,其具有工艺简单、污染小、投资少、成本低等优点。本工作针对废旧塑料的分选回收利用,详细介绍了摩擦电选的荷电机理、影响因素、荷电装置和分选设备的研究现状,指出了目前通过摩擦电选回收废旧塑料的技术问题,并对摩擦电选技术未来的发展趋势和应用进行了展望。     

超细矿渣粉在水泥颗粒中的密实填充作用

超细矿渣粉可以填充水泥基材料内部孔隙,改善其微观结构和宏观性能。采用微粉堆积密度测定仪法、Puntke饱和点用水量法、LCPC(法国路桥实验中心)最小需水量法、浆体相对密度法、标准稠度需水量比法5种试验方法定量分析了超细矿渣粉掺量对水泥-超细矿渣粉体系堆积密实度的影响,并将这5种试验方法测定的结果与Reschke理论计算值、Andreasen方程-灰色关联分析结果、Aim-Goff模型预测值进行了对比分析。结果表明,采用不同测试或分析方法得到的水泥-超细矿渣粉体系堆积密实度差异较大,但水泥-超细矿粉体系堆积密实度随超细矿渣粉掺量变化的趋势基本一致。浆体相对密度法和标准稠度需水量比法等方法,对胶凝材料体系堆积密实度的变化更为敏感,更适用于表征胶凝材料体系的堆积密实度。Aim-Goff模型预测结果与试验测试结果基本一致,且对堆积密实度的变化也较为敏感,建议采用Aim-Goff模型预测胶凝材料体系堆积密实度的变化规律。     

Zur Verfestigung von Schüttgütern – Mikroprozesse und Kinetikmodelle

Storage tanks are important elements of a self-operating closed processing system. The reliability and availability of storage equipment essentially depends on the flow behaviour of particulate solids in storage containers. A wide residence time distribution (i.e. too long a storage time at rest) in silos, bunkers or transportation containers, respectively, can lead to the hazardous problem of so-called “time consolidation” of particulate solids. During this hardening process, solid bridges are forming with resulting solidification and solid properties of bulk material. In principle, there are four main physico-chemical effects in bulk materials storing and handling which can produce solid briding between the particle contacts due to crystallisation, chemical reactions, solidification of high-viscous bonding agents and sintering. Generally, new adhesion force based models are presented to describe the consolidation kinetics of particulate solids. Preliminary solutions of kinetic model equations are discussed and compared with new test results and practical conclusions are drawn concerning the reliable processing, storage and transportation of bulk materials.