bluuebunny/crossref_metadata_2025_split huggingface dataset:
Werkstoffentwicklung für gasgekühlte Hochtemperaturreaktoren zur Erzeugung nuklearer Prozeßwärme
Authors: Nickel Hubertus 
Published: December 2004

AbstractZur Bereitstellung nuklearer Prozeßwärme auf dem für endotherme chemische Prozesse erforderlichen Temperaturniveau zwischen 950 und 1000 ßC bietet sich der gasgekühlte Hochtemperaturreaktor (HTR) mit Kugelhaufen‐Core an. Die derzeitige Weiterentwicklung zielt zur nuklearen Prozeßwärmeanlage hin. Zu deren Verwirklichung werden umfangreiche Untersuchungen an Werkstoffen für hochbeanspruchte Core‐ und Primärkreis‐Komponenten durchgeführt. Bei der Diskussion der Core‐Komponenten wird über den heutigen Kenntnisstand und die Zielsetzung der Weiterentwicklung kugelförmiger Brennelemente, beschichteter Brennstoffteilchen und Strukturgraphit berichtet. Für die Primärkreis‐Komponenten sind zur Konstruktion von Heißgasleitungen, Spaltrohren für Methan‐Reformierung und Wärmeaustauschern für einen Helium/Helium‐Zwischenkreislauf neben einigen keramischen Materialien vorwiegend metallische Werkstoffe vorgesehen. In reaktorrelevantem Helium können dessen gasförmige Verunreinigungen bei den eingesetzten Ni‐ und Fe‐Basis‐Hochtemperatur‐Legierungen zu teilweiser Oxidation bzw. Aufkohlung und damit zur Herabsetzung der Zeitstandfestigkeit führen. In diesem Zusammenhang wird über die erstellte Prüfkapazität zur Untersuchung der Zeitstandfestigkeit unter konstanter Last bzw. bei Wechselbeanspruchung und des Korrosionsverhaltens der metallischen Legierungen in reaktorrelevantem Helium und in Prozeßgas berichtet. Schließlich werden erste Ergebnisse über das Zeitstandverhalten mehrerer Legierungen in verunreinigtem Helium diskutiert.
Welche Chancen hat der deutsche Apparatebau bei den weltweiten Investitionen der Chemie?
Authors: Lipphardt Günter 
Published: December 2004

AbstractWhat are the chances for the equipment manufacturers with the worldwide investments of the chemical industry? For years now the investment of the chemical industry in Germany is stagnant. A change of this situation for the near future cannot be expected. The export of plant equipment however has been increased considerably since the oil crisis. The chances as well as the risks of the equipment manufacturers as far as the worldwide investment of the chemical industry is concerned are being investigated. In particular this study deals with the situation in the developing countries, poor as well as rich in raw materials, in the Comecon countries and in the industrial countries. Furthermore the possibilities of exporting plant equipment, directly or via engineering companies or production of this equipment abroad are discussed.
Kristallisation — ein thermisches Trennverfahren
Authors: Matz Günther 
Published: December 2004

AbstractCrystallization – a Thermal Unit Operation. After a definition, this review summarizes important methods of growing single crystals (solution and melt operations), mass crystallization from melts and the gas phase, fractional crystallization (from solution and melts), simple mass crystallization from solution either as cooling, as evaporative, or as vacuum crystallization and necessary equipment, and describes classifying crystallizers. The special crystallization methods described are: reaction crystallization, precipitation, freezing out, adduct crystallization, and zone freezing. Among the peculiarities of crystallization, details are given of the crystal size distribution, habit modifications, Ostwald ripening, the growth rate of the small grain, and prilling.
Regeneration von Abfallschwefelsäure
Authors: Bodenbenner Kurt , Von Plessen Helmold , Steiner Rudolf 
Published: December 2004

AbstractRegeneration of spent sulphuric acid. Several processes are available for the regeneration of spent sulphuric acid. Generally, the dilute acids containing at least 20% of H2SO4 are preconcentrated to 60 – 70% and then either further concentrated to over 90% or decomposed to SO2. Purifying operations can be combined with these steps. Spent sulphuric acid highly contaminated with inorganic and organic compounds can frequently only be regenerated after a prior purification step, e. g. by extraction of electrolysis. Dilute spent sulphuric acid containing less than 20% of H2SO4 can also be regenerated, but the costs incurred by evaporation increase out of proportion with decreasing sulphuric acid concentration.
Fortschritte verfahrenstechnischer Forschung durch die Radionuklidtechnik
Authors: Merz Albert , Vogg Hubert 
Published: December 2004

AbstractAdvances in Process Research by Radionuclide Techniques. Modifications and transformations of materials and their technical implementation in process systems require movement of materials. Radionuclide techniques can greatly help in understanding and describing these mechanisms. Their advantage lies in the contactless measurement of radioactively labeled flows of materials by the radiation emitted even through thick walls of equipment. Even under rigorous process conditions (high pressures, high temperatures), for instance, residence time distribution functions can be determined at any point in a process system without interfering with the system. This specialized measuring technique is demonstrated by three examples selected from various fields of process technology. Radioactive tracer studies performed on a rotary kiln helped, inter alia, to establish a subdivision into process zones and to pinpoint areas of dust generation. Mixing and feeding actions were studied in a twin screw extruder equipped with a special screw and mixer disk arrangement. Tracer experiments conducted in two secondary settling basins indicate the differences in the mechanisms of movement of the aqueous phase if the mean residence time and the residence time distribution may be influenced not only by hydraulic loads, but also by design variants of the overflow flumes.
Kunststoffe im Rohrleitungs‐ und Apparatebau
Authors: Gaube Erwin , Diedrich Georg 
Published: December 2004

AbstractPlastics in pipeline and plant construction. Stability calculations in the construction of plant with thermoplastics and glass‐fibre reinforced plastics are discussed, and the relevant stress characteristics, resistance factors, welding factors, and weakening and safety parameters are outlined. Possible ways of testing such equipment before commissioning of plant are described, and previous experience from practice is reported. The article concludes with a list of previously used standards and regulations.
Überblick über die Anwendungsmöglichkeiten von Festelektrolyten
Authors: Baukal Werner , Knödler Reinhard , Kuhn Wolfgang 
Published: December 2004

AbstractApplications of solid state electrolytes – a survey. Ionic conduction in solids has numerous potential applications in the fields of instrumentation, energy storage, energy conversion, and production of chemicals. The present state of development of the various processes and devices ranges from industrial maturity via application tests and R & D work to projects in the concept stage. The state of the art is briefly reviewed.
Extraktionskolonnen mit rotierenden Einbauten
Authors: Marr Rolf 
Published: December 2004

AbstractExtractors agitated with rotating stirrers. Methods for the calculation of height and diameter of extractors with rotating stirrers (RDC, ARD, Kühniextractor, RZE, etc.) are considered and the significance of single drops in the design of agitated extractors is discussed. The dimensioning and scaling‐up of extractors are explained. Equations illustrate the basic importance of hydrodynamics, mass transfer, and longitudinal mixing. The possibility of designing agitated extractors on the basis of this concept is outlined.
Akustische Planung von petrochemischen Freianlagen — Möglichkeiten, Grenzen, Erfolge
Authors: Grashof M. , Kauth R. , Smolen H. 
Published: December 2004

AbstractAcoustic planning of open‐air petrochemical plants. Open‐air petrochemical plants can no longer be built without taking adequate steps regarding noise reduction. This necessitates a knowledge of the state of acoustics technology and its realizable scope of development. Economically, and from a production point of view, noise reduction can optimally be achieved only by acoustic planning prior to construction, since experience has shown that modifications of existing plant are less effective and often present operational difficulties. Acousting planning often calls for harmonizing conflicting requirements. This problem is illustrated using the construction of an extraction plant and an olefin plant as examples. In particular the main sources determining the sound level are dealt with, such as furnaces, waste heat recovery compressor houses, air‐coolers, piping and control valves, as well as pumps and electric motors. Successful efforts in acquiring a technique safe in operation and satisfactory in sound reduction are highlighted.
Technische Projekt‐ und Arbeitsorganisation in Anlagenbauunternehmen
Authors: Gelbe Horst 
Published: December 2004

AbstractEngineering project and labour organization in plant construction companies. Problems and trouble‐shooting in the organization of engineering projects are discussed with special emphasis being laid on the prerequisites for the use of matrix‐oriented company structures. The current form of project organization, the tasks of project management, the make up of the project team, the project directives and general prerequisites of works organization which are embodied in factory rules and regulations are dealt with.
Einsatz der EDV bei der Beschaffung von Apparaten für Chemieanlagen
Authors: Helfrich Fritz , Dostmann Peter , Spiesberger Horst 
Published: December 2004

AbstractUse of electronic data processing on procurement of equipment for chemical plant. Numerous individual data and time‐limits have to be collected and processed on procurement of equipment for chemical plants. The requirements as to access and evaluation, velocity and transparency of information passage were not met by the “Kartex” cardfile previously used. Electronic data processing was introduced to remove difficulties and bottlenecks during design, construction, delivery, and compilation of information: these problems were indeed solved by using an IBM computer with IMS. The data file recalled by a monitor permits description of principal data, rationalization of flow of work, external and internal supervision of deadlines, evaluation of stored data according to fixed or variable criteria.
Wirbelschicht‐Technologie: Neuentwicklungen für Kraftwerkstechnik und Umweltschutz
Authors: Werther Joachim , Holighaus Rolf 
Published: December 2004

AbstractFluidized bed technology: recent developments for power station engineering and pollution abatement. The principle of fluidization has been successfully applied to numerous areas of chemical engineering. Combustion of coal in a fluidized bed consisting of particles of ash and limestone or dolomite permits low‐pollution utilization of coals having lower heating values or high sulphur contents without any need for removing sulphur from the exhaust gases. The present state of the art and world‐wide development work on fluidized combustion are considered, as are the future prospects of this new energy technology.
Der Verfahrensingenieur in der chemischen Industrie
Authors: Schlachter Hans 
Published: December 2004

AbstractThe Process Engineer in the Chemical Industry. Tasks and problems are dealt with which the process engineer in the chemical industry has to perform or solve together with scientists. At present the problems are caused primarily by the rapid price rises for power and raw materials which have occurred in the past few years, and by the increased efforts on environmental protection. Future problems which are already becoming clearly discernible concern the development of resources which will be available over the long term to supply raw materials and power and also food for the rapidly growing world population. The chemical industry must make a decisive contribution to this development, and we must decide now on the direction it is to take. The process engineer has a key role to play in the accomplishment of these manifold and difficult tasks. This article describes the requirements he must satisfy and the conclusions which must be drawn in regard to his education and training.
Dampfexplosionen durch Kontakt zwischen Wasser und heißen Schmelzen
Authors: Fröhlich Georg 
Published: December 2004

AbstractVapour explosions produced by contact between water and hot melts. A vapour explosion can occur on contact between two liquids of different temperatures if the temperature of the hotter liquid is higher than the boiling point of the cooler one. The explosion is due to very rapid vapour generation (phase transition of the cooler liquid). Vapour generation must be preceded by very good heat transfer by a fragmentation process with an enormous heat transfer coefficient. Experimental results are discussed for water as the cooler liquid and melts of glass or metal (Ga, Pb, Al, Cu, Fe) as the hotter liquid. The probability of the occurrence of steam explosions depends on the material of the melt, the temperatures of the two liquids (not only their temperature difference), the reacting masses, the shape of the device in which the reaction is to occur, and external triggering.
Wirkungsweise und Charakterisierung multifunktioneller Autoabgas‐Katalysatoren
Authors: Koberstein Edgar , Völker Herbert 
Published: December 2004

AbstractMode of action and characterization of multifunctional automotive exhaust catalysts. Because of the pending reduction in permissible concentration of toxic components in automotive exhausts the catalysts presently available will have to be replaced by more efficient systems. For these “second generation” catalysts multifunctional platinum/rhodium based catalysts are in the course of development, with provision being made for control of the fuel/air mixture. The new catalysts destroy both NOxas well as carbon monoxide and hydrocarbons and are effective in the neighbourhood of the stoichiometric composition of the fuel/air mixture. The mode of action of the new “three‐way” catalysts is described in detail and the present trends in development are outlined.
Zum Stand der Kohlevergasung
Authors: Franke Friedrich H. 
Published: December 2004

AbstractGasification of coal – a status report. On the basis of industrially available conventional coal gasification processes (Winkler, Koppers‐Totzek, and Lurgi pressure gasification) the paper describes developmental trends in such processes. Elevated operating pressure is a common feature of all new processes, thus opening up new applications. An economic incentive to the development of new gasification processes also comes from combinations with new technologies, e. g. with direct reduction. Moreover, an advanced version of the high‐temperature Winkler process is described and evaluated in comparison with conventional commercial processes. Apart from processes conducted above ground, recent developments also include thoughts about underground gasification.
Stabilität und Dynamik heterogen‐katalytischer Reaktionssysteme
Authors: Eigenberger Gerhart 
Published: December 2004

AbstractStability and Dynamics of Reactors with Heterogeneously Catalyzed Reactions. Our knowledge of causes and consequences of problems arising from instability and dynamic effects in reactors with heterogeneously catalyzed reactions has increased remarkably in recent years. Especially thermal effects, caused by the self‐acceleration of an exothermic reaction in combination with heat and mass transport, are now well unterstood. In addition kinetic effects, i. e. phenomena which have to be explained by the kinetic peculiarities of surface reactions, have attracted increasing interest. For both cases the state of the art will be reviewed, highlighting the physical and chemical causes of the observed phenomena.
Unerwünschte Reaktionen organischer Stoffe als Gefahren in Chemieanlagen
Authors: Grewer Theodor 
Published: December 2004

AbstractUndesired reactions of organic substances as sources of danger in chemical plant. In chemical production processes, danger can arise both from the intended exothermal reaction and from unintended exothermal reactions. Such “undesired” reactions may be exothermal reactions of the substances themselves (e.g. decomposition, polymerization) or reactions of the substances involved with one another (e. g. of a reactant with the solvent). Differential thermal analysis and warm storage have been successfully used in various modifications as experimental methods for the study of such reactions. For exothermal decomposition reactions, correlations can be made between the chemical constitution of the substances and the energy released on decomposition, as well as the temperature of incipient decomposition. In mixtures with other substances a modified decomposition behaviour must be expected, usually of such a kind that the temperature range of decomposition is lowered. There are many possible exothermal reactions of substances with one another; only a few have hitherto been studied in detail.
Energie‐Einsparung — eine Herausforderung
Authors: Elgeti Klaus 
Published: December 2004

AbstractEnergy saving – a challenge. Between 1955 and 1976, the specific energy consumption – i.e. the energy consumption referred to the net production volume at constant prices – in the Federal German chemical industry fell by ca. 70%. Thus in 1977 this branch of industry accounted for only 8.4% of the primary energy consumption of the national economy. The possible reasons for this trend lie in a highly dynamic approach to product development, fast growth, and energy‐conscious training of process engineers. The future should see further savings resulting from advances in thermal separation processes by introduction of process computers and – in the long term – by developments in catalysis.
Sicherheit in der Verfahrenstechnik
Authors: Kremer Gottfried 
Published: December 2004

AbstractSafety in the field of chemical engineering. This article discusses whether the risks involved in technology have increased, why such severe criticism is expressed concerning safety in plants, and whether there has been any change in the criteria that the public applies to safety. The accident statistics of the employers' association indicate the improvements in safety that have been achieved and by no means suggest any increase in the risks involved. The reason for the frequent and severe criticism of safety appears to be a widespread ignorance of production processes and a mistrust that evolves from such ignorance. Thus it is necessary to provide the public with still more and still better information. For this purpose the chemical industry needs an unbiased press that strives for impartiality. Among the criteria applied nowadays, a consideration of the advantages and disadvantages of a technical development is frequently lacking and a trend towards forecasting methods can be ascertained. The chemical industry is prepared to provide frank information and to engage in an objective discussion of safety topics.
Stand der Texaco‐Kohlevergasung in der Ruhrchemie/Ruhrkohle‐Variante
Authors: Cornils Boy , Hibbel Josef , Langhoff Josef , Ruprecht Peter 
Published: December 2004

AbstractRuhrchemie/Ruhrkohle variant of the Texaco coal gasification process – a status report. In pilot operation since January 1978, the Ruhrkohle/Ruhrchemie variant of the Texaco coal gasification process has produced a total of 20 million m of synthesis gas having an average composition of 46% CO, 34% H2, 19% CO2, 0.3% H2S, 0.6% N2, and 0.1% CH4 from ca. 12 000 tonnes of coal. As the first of the „second generation”︁ coal gasification processes, the Texaco process has proved itself capable of gasifying pulverized coal of all grades at high temperatures and pressures. The next goal is an increase in capacity from that of the demonstration plant at Oberhausen‐Holten (12 000 m/h) to ca. 100 000 m/h.
Ermittlung optimaler Betriebseinstellungen für technische Wirbelschichtreaktoren
Authors: Werther Joachim , Hegner Bernd 
Published: December 2004

AbstractDetermination of optimum operating conditions of industrial fluidized bed reactors. Fluidized bed technology has long been successfully used in numerous industrial processes. Nevertheless, the design and optimization of fluidized bed reactors still give rise to considerable difficulties owing to the complex nature of the gas/solids flow. Advances in the mathematical description of fluidized bed reactors have now been made by formulation of a model describing the catalytic reaction in a gas/solids fluidized bed in terms of absorption of reactants from the bubble phase with subsequent pseudohomogeneous reaction in the catalyst suspension surrounding the bubbles. Empirical relations are reported for mass transfer, specific transfer area, and bubble gas hold‐up, taking into account the influence of fluidized‐bed geometry which is of great importance in scale‐up. The state of development reached and the practical use of the model is demonstrated by evaluation of various reactions taken from the literature. Any desired reaction mechanism can be incorporated into the model. It is shown for the example of the selectivity behaviour of a system of consecutive reactions that a detailed knowledge of the reaction kinetics is a necessary condition for the design and operational optimization of industrial fluidized bed reactors.
Maximaler Wärmeübergang in Apparaten mit dispersen Zweiphasensystemen
Authors: Mersmann Alfons , Noth Hermann , Ringer Detlev , Wunder Rainer 
Published: December 2004

AbstractMaximum heat transfer in apparatus containing dispersed two phase systems. The structure of dispersed systems such as fluidized beds, bubble columns, and liquid/liquid spray columns in process apparatus can be either homogeneous or heterogeneous. When calculating heat transfer coefficients between such systems and vertical heat transfer areas it is necessary to know the structure of the bed. In homogeneous systems (for instance fixed beds) a relationship between the heat transfer and a Reynolds number was found. This Reynolds number embodies the volumetric flux density and a suitable hydraulic diameter. In gas fluidized beds with a heterogeneous structure the heat transfer depends on a Péclet number. The characteristic time of this number can be obtained by deviding the particle diameter by the mean rising velocity of gas bubbles. Maximum heat transfer coefficients for homogeneous and heterogeneous and heterogeneous systems can be described in a general way by plotting a Nusselt number versus the product Arp · Prc of the Archimedes number and the Prandtl number. Maximum coefficients are calculable without knowledge of the volumetric flux density. For low values of the product Arp · Prc there is a significant difference between homogeneous and heterogeneous beds.
Fraktionierte Kristallisation
Authors: Matz Gustaf 
Published: December 2004

AbstractFractional crystallization. The operations of fractional crystallization, comprising at least a single crystallizing and remelting (redissolution) step, differ from each other in the number of the realized theoretical stages and the method of separating the crystallisate and residual melt or mother liquor. Fractional crystallization from solutions resemble liquid‐liquid extraction, but fractional crystallization from melts is similar to rectification. There is a choice between operations with a series of temperature‐controlled vessels and counter‐current operations. Many fractional crystallizers are purifiers for high qualities; crystals generally exist only within them apparatus.