bluuebunny/crossref_metadata_2025_split huggingface dataset:
Meßmethoden in Fermentern unter sterilen Bedingungen
Authors: Onken Ulfert , Buchholz Rainer 
Published: December 2004

AbstractMeasuring methods for fermentations under sterile conditions. In process development as well as in industrial production it is necessary to obtain information about the state of the process by the measurement of characteristic variables. This is true for bioengineering in the same way as for chemical processes in general. Characteristic variables to be taken into consideration include temperature, pressure, masses and mass‐flow rates, operating parameters such as liquid level and impeller speed, and especially the concentrations of reactants, intermediates, and products. In contrast to other processes, a particular problem exists in fermentation because introduction of microorganisms, into the system by the measurement has to be prevented. Since taking samples from the reactor is hardly suitable for controlling the process for various reasons (amount of work, loss of time), this review considers only those methods which can be used for measurements directly in the fermentor. Essentially these are physical and physico‐chemical methods, e. g. for concentrations (O2 and CO2 in gas and liquid phase, pH, biomass). Of special interest for future development are spectroscopic and enzymatic methods for fast determination of substrates and of important intermediates and products. Here the sterility required entails special problems in the case of enzyme electrodes. Important information on the state of the process can, of course, also be obtained from physical variables, such as gas hold‐up, bubble size, viscosity, and turbulence properties of the medium. These variables are less critical with regard to sterility.
Die Wirbelschicht in der Feuerungstechnik — Stand und Aussichten
Authors: Schilling Hans‐Dieter 
Published: December 2004

AbstractFluidized‐bed firing technology – State of the art and prospects. After categorizing fluidized‐bed combustion according to process engineering criteria, the following features are then discussed on the basis of R & D results and of experience gained with demonstration units over the past four years: the range of feed coal qualities, combustion intensity, cleanness (SO2, NOx, CO, halogen, dust, disposal properties, and usability of residues), flexibility for partial load operation, and availability. The system‐inherent possibilities could be exploited to such an extent that initial commercial application is within reach. Furthermore, significant improvements seem to be possible. The intial results obtained with binding of fluorine are to be regarded as positive, large‐scale feasibility, however, still needs to be proven. Economic criteria are dealt with. The state of technology worldwide is discussed as well as modified experimental plants and facilities. Possibilities of further development are pointed out.
Einsatzmöglichkeiten drehzahlregelbarer Drehstromantriebe in der chemischen Industrie
Authors: Nachtkamp Jürgen 
Published: December 2004

AbstractApplications of variable speed three‐phase motors in the chemical industry. For good reasons, three‐phase motors are used very widely in the chemical industry. Their considerable operation advantages have formerly been offset by the drawback of an invariant speed. Since the use of variable‐speed three phase motors (with transistor and thyristor technology) has become economical in various applications, new opportunities are opening up for chemical engineering. In order to demonstrate the wide application of this new technology, the article first surveys the electric motors used in a large chemical plant. The two principal motivations for using variable speed three‐phase motors are then considered, viz. energy saving and chemical engineering improvements, and the attainable advantages are set out against the technical and economical limitations on use. In conclusion, the risk of breakdown of variable speed three‐phase motors is discussed in relation to conventional technology.
Die Struktur turbulenter Freistrahl‐Diffusionsflammen
Authors: Peters Norbert 
Published: December 2004

AbstractThe structure of turbulent jet diffusion flames. This review considers recent developments in the description of kinetic effects in turbulent jet diffusion flames without swirl. The model of laminar flamelets is introduced, which allows description of effects far from chemical equilibrium – for instance local quenching phenomena. A similar solution is given for the equations governing round jet flames. Finally, relations for the mean chemical reaction rate and the formation rate of NO are derived. The article concludes by mentioning recent investigations on flame stability.
Nichteisenmetalle im Apparate‐ und Anlagenbau
Authors: Köcher Reiner 
Published: December 2004

AbstractNon‐ferrous metals in construction of equipment and plant. The use of copper, copper/nickel alloys, highly corrosion resistant NiMo alloys, titanium, zirconium, and tantalum is described with the aid of examples. Brief mention is also made of the corrosion‐resistance of the above materials of construction. It is shown that a plate design of pressure vessels has economic and technical advantages over a solid design. Properties and working of plated composite materials are considered. An account of the lining of large‐scale chemical reactors with copper‐plated sheets is also provided with actual examples. The quality of production of tube mountings is described in the case of titanium heat exchangers, paying particular attention to drift attrition behaviour, reduction of wall thickness, and tube welding procedures. Tube fixing in heat exchangers made of NiMo28 is briefly mentioned.
Ermittlung sicherheitstechnischer Kenngrößen explosionsfähiger Gasgemische
Authors: Hofmann Hanns , Schmidt Gerhard 
Published: December 2004

AbstractDetermination of safety characteristics for explosive gas mixtures. This paper presents equipment for determining safety characteristics such as explosion limits, flame temperatures, and laminar flame velocities. Contactless methods of measurement such as infrared thermography, interferometry, and Laser‐Doppler anemometry are of particular importance. By means of selected gas mixtures it is shown that the composition of the gas mixture, the initial temperature and, as far as explosion limits are concerned, also the type of ignition source are important parameters. Finally, the influence of additives is reported which even in relatively small quantities strongly modify the whole combustion process and are therefore also relevant in safety problems.
Neue konstruktive und prozeßtechnische Konzepte für die Wasserstoff‐Gewinnung durch Elektrolyse
Authors: Wendt Hartmut 
Published: December 2004

AbstractNew design and process engineering concepts for production of hydrogen by electrolysis. Electrolytic production of hydrogen has attracted particular interest in connection with expansion of nuclear generating capacity in France, Belgium, Canada, and Japan as a means of balancing load, and for developing countries with hitherto untapped hydroenergy resources it provides a means of supplying fertilizers with any need for oil imports. However, the present state of the art of water electrolysis leads to excessively high production costs owing to excessively high investment costs and to high an energy consumption, far above the thermodynamically calculated energy requirements: reduction of production costs will require satisfaction of opposing demands for raising the space‐time yield of electrolyzers by increased current density while simultaneously lowering the energy consumption by reducing the cell potential. This contribution describes measures intended to save 20 to 30% in energy requirements; the production costs will fall by about 20 to 25%.
Einsatzbereich des Werkstoffes Glas in der Anlagentechnik
Authors: Pilhofer Theo 
Published: December 2004

AbstractScope of glass as material of construction in plant engineering. In conjunction with PTFE as sealing material, borosilicate glass is nowadays recognized as a material for plant construction. A complete modular system of individual components with suitable connecting pieces is available. Moreover, a variety of equipment has been developed for accomplishing various processes while paying due attention to the special material properties of the material glass. In combination with other materials, primarily in the field of heat exchangers and evaporators, numerous processes are now conducted without any difficulty in glass plant. In this range of processes, a special place is assumed by those which urgently require glass for corrosion reasons, such as chlorination or bromination reactions or concentration of acids, because specialized know‐how is sometimes required.
Maßnahmen zur Intensivierung des Wärmeübergangs
Authors: Stephan Karl , Mitrović; Jovan 
Published: December 2004

AbstractMeasures for intensifying heat transfer. Various approaches to the intensification of heat transfer have occupied engineers for many years. Many proposals failed to be accepted while others have been adopted in practice and have led to considerable savings in energy and materials. This article considers a number of topical developments in the improvement of convective heat transfer, heat transfer on evaporation, and heat transfer on condensation. The authors cite primarily review articles from among the extensive body of literature pertaining to this field of study.
Trägerbiologien in der Abwassertechnik
Authors: Oehme Christian 
Published: December 2004

AbstractSupport biologies in waste water technology. The numerous possibilities of immobilizing biomass and using it fixed on a wide range of carriers in the available types of reactors is matched by a great variety of practical applications in waste water purification technology for partial, complete, subsequent, and ultrapurification. All support biologies share the following advantages to a greater or lesser extent: smaller reactor volumes and shorter reaction times thanks to higher biomass concentrations; volume reduction or elimination of subsequent purification pools owing to the more favourable sludge index and fixation in the reactor or the filter; long sludge lifetimes are possible (favourable for slowly multiplying nitrifiers and specialist strains); no floating sludge formation on carbohydrate degradation or nitrification; increase in process stability and degradation activity towards refractory compounds which are difficult to degrade biologically if suitable supports showing synergistic activity are used, such as highly porous activated charcoal.
Systeme zum Ein‐ oder Austrag von Schüttgütern in oder aus Druckräumen
Authors: Stahl Werner , Stadler Reinhold 
Published: December 2004

AbstractSystems 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.
Informationshaushalte in Labor und Produktion
Authors: Peters Rolf Wolfgang 
Published: December 2004

AbstractInformation management in laboratory and production. The competitive situation is compelling companies to reduce production costs, to improve product quality, and to react very fast to changing market requirements of product properties. Apart from these necessities, the material flow itself needs to be optimized with the aim of reducing stockpiles of raw materials and of intermediate and finished products without sacrificing flexibility and ability to fulfill orders. These demands can only be met when the informations accompanying the production process have been mastered. An overview of all data accruing in the areas of production and the laboratory is essential. Together these data represent the information flow of laboratory and production plant. Modern semiconductor technology permits cost‐saving construction of powerful information systems which have meanwhile become an essential competitive factor. This article attempts to provide an introduction to phase and layer models, and thus to offer structuring aids.
Mensch‐Prozeß‐Kommunikation
Authors: Färber Georg , Polke Martin , Steusloff Hartwig 
Published: December 2004

AbstractMan‐process communication. Computers are extensively used to control technical processes, but man is still irreplacable as observer and decision maker. The paper gives an overview of the channels existing between man and process. These channels have to deliver as much information as necessary, but as little as possible to allow the right decisions. Good models, concerning the production process and its individual phases, the structure of the control system, and the behaviour of man are required to extract the relevant information out of a large amount of data. Methods of signal processing and pattern recognition help to reduce the dimensionality of the active state vector allowing the control system to provide „information”︁ instead of a collection of „signals”︁. The paper also describes the state and future development of important technological aspects, e. g. interactive display systems and real time data base systems.
Mischen in Schneckenmaschinen, Teil 2: Suspendieren, Desagglomerieren und Emulgieren
Authors: Pahl Manfred H. 
Published: December 2004

AbstractMixing in screw mixers, Part 2: Suspension, de‐agglomeration, and emulsification. This paper explains the physical laws pertaining to the suspension of solids in liquids, to deagglomeration, and to mixing of immiscible liquids; some results from these different fields are also presented. In fibre reinfored plastics the length of the fibres must be great and the distribution of their length must be narrow. The product undergoes little grinding on using mixing with low shear stresses, feeding with fibres that are not too long, and adding the fibres to the melt. Pigments and some other additional materials tend to agglomerate. De‐agglomeration is necessary to improve the products. It is determined by the adhesion and the force number, which is the product of velocity and time of shearing. Taking suitable action will ensure minimized abrasion in case of abrasive material. A size distribution of droplets will be found if there is only a limited miscibility of liquids. Only size reduction will improve the homogeneity. The velocity of shearing, the interfacial tension, and the ratio of the viscosity of the components, all play a role in this process.
Auswahl und Betrieb von Brüdenverdichtern in chemischen Produktionsanlagen
Authors: Mangartz Karl‐Heinz , Handl Roland 
Published: December 2004

AbstractChoice and operation of vapour compressors in chemical production plant. The use of vapour compressors for evaporation, distillation processes and also for more complex processes has increased greatly due to the large increases in energy costs in the past. Generally, high speed radial compressors are used for these applications. Recommended operating ranges, investment costs as well as efficiencies at different compression ratios are explained, based on experience gained in technical application and manufacturers information. The example of combining a separation column and an evaporation step shows that not only a saving of energy, but also a significant reduction of waste water generation is achieved. The control strategy for a process having several recycle flow streams is explained. Based on operating experience, recommendations for field monitoring of the compressor are given.
Blasensälen — Erkenntnisstand und Entwicklungstendenzen
Authors: Deckwer Wolf‐Dieter , Schumpe Adrian 
Published: December 2004

AbstractBubble columns – present knowledge and future trends. Considering the abundance of phenomenological and empirical studies on bubble columns, future research and development should place greater emphasis on theory. This paper therefore reports on suggested theoretical concept, new hydrodynamic models, and results of turbulence theory, and considers their potential influence on the development of new reactor models for bubble column reactors.
Verwendung von Kohlendioxid bei technischorganischen Synthesen
Authors: Behr Arno 
Published: December 2004

AbstractUse of carbon dioxide in industrial organic syntheses. Although carbon dioxide is important as an abundant carbonaceous raw material, its utilization in chemical processes so far has been rather limited. This review covers the reactions of CO2 employed in industry, such as the production of urea, the Kolbe‐Schmitt reaction, the synthesis of cyclic organic carbonates, and the use of CO2 in methanol synthesis. Interesting recent developments in CO2 chemistry, especially the transition metal catalyzed reactions, are also elucidated. In addition to the synthesis of polymers and hydrocarbons, the production of oxygen‐containing chemicals seems to be very profitable and attractive for future industrial applications. Not only can derivatives of formic acid and carbonic acid be formed but longer‐chain carboxylic acids and their derivatives are also accessible by reactions of carbon dioxide with hydrocarbons such as alkynes, alkenes, and 1,3‐dienes.
Packungskolonnen
Authors: Mersmann Alfons , Deixler Alfred 
Published: December 2004

AbstractPacked columns. Packed towers with dumped or regular packings are widely used in industry for accomplishing chemical engineering processes. Packed columns are able to work economically even under extreme process conditions (e. g. vacuum, high temperature, aggressive flow mediums), because of the available variety of packing types and the straight‐forward manufacture of the individual packing elements from almost any material. The present contribution shows the different kinds of packings arranged according to their geometry and physical properties. A packed tower for gas/liquid countercurrent operation is shown as a basic construction with the necessary internals. Since packed columns are mostly used in gas/liquid countercurrent operation, the fundamentals of fluid dynamics and mass transfer are presented for this operating condition.
Die elektrochemische Fluorierung – ein Überblick
Authors: Hollitzer Enno , Sartori Peter 
Published: December 2004

AbstractElectrochemical fluorination – a review. The versatile method of electrolysis in hydrogen fluoride solution or suspension is reviewed. An attempt is made to give separate definitions for the different methods of electrochemical fluorination. In addition a supplement, containing tables of all papers and patents published in the past ten years is available.Eine beschränkte Zahl von Kopien kann bei Prof.Sartoriangefordert werden.
Stand und Entwicklung der kontinuierlichen gravimetrischen Dosierung von festen und flüssigen Stoffen
Authors: Gericke Hermann 
Published: December 2004

AbstractState of the art in continuous feeding of solids and liquids. After defining the characteristics of continuous gravimetric feeding systems, the author lists the aims and reasons for the application of these methods in one‐ and multiple component systems. We can distinguish between gravimetric feeders with positive gross weighing and negative net weighing. The latter principle has advantages in operation, and is embodied in the weight‐loss weigh feeders. A synoptic chart of the various gravimetric feeder designs shows the nature and the method of acquisition of the controlled value and also classifies the fields of application as to feed range and material characteristics. When designing a feeder, the weight and volume of material flow, the characteristics of the weight resolver and of the metering device have to be considered. Latest developments of the principal components of weigh feeders are illustrated by examples, such as metering devices for solids with poor flow properties, combination of feeding and pneumatic conveying systems, headload compensation with weight‐loss weigh feeders, feeding with high instantaneous accuracy, gravimetric feeding of liquids at small feed rates, set point and ramp programming, and monitoring of the bulk density of the material.
Korrosion und Korrosionsschutz in Systemen mit neuen Energieträgern und Brennstoffen
Authors: Heitz Ewald 
Published: December 2004

AbstractCorrosion and corrosion protection in systems utilizing new energy sources and fuels. New energy carriers such as methanol, ethanol, hydrogen, and biogas are of increasing interest for the substitution of the fossil fuels oil, natural gas, and coal. The analysis of production, handling, and use of such energy carriers with regard to materials and corrosion protection technology gives various results. Some of the problems can be solved by conventional technologies (production of ethanol and biogas). For others, further development work is needed (production of methanol; methanol and ethanol as substitute motor fuels). The problems encountered within the framework of a hydrogen energy technology are known and can be solved for the handling of hydrogen but they are still unsolved for special production processes (hybrid processes with sulfuric acid).
Rechnergestütztes Experimentieren in der chemischen Reaktionstechnik
Authors: Hofmann Hanns 
Published: December 2004

AbstractComputer‐aided experiments in chemical reaction engineering. In recent years, relatively inexpensive microcomputers have become available which are very suitable for data acquisition, data storage, data handling, and for control and experimental design of laboratory reactors in reaction engineering. Various experimental set‐ups (integral, gradientless, and pulse reactors) as built in the Institute for Technical Chemistry I of Erlangen‐Nürnberg University are presented, their advantages and remaining problems discussed, and some results on kinetic analysis and reaction modelling reported.
Reinigung von Apparaten und Rohrleitungen
Authors: Sangen Mathias , Sckuhr Peter 
Published: December 2004

AbstractCleaning of equipment and piping. There has been an increase in the study of the causes of contamination and its appearance in equipment and piping. The increasing demands placed on the cleanliness of production plant for pharmaceutical and biochemical products has enhanced interest in industrial cleaning methods. Precisely this area will increase in importance in the future because this is where preventative measures and automation of cleaning will obviate the need for – frequently unpleasant – cleaning operations and at the same time effectively increase the capacity of a given plant.