bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kriterien für die Auswahl und die Auslegung von Gas/Flüssigkeits‐Reaktoren
Authors: Nagel Otto , Hegner Bernd , Kürten Heribert 
Published: December 2004

AbstractCriteria for the choice and design of gas/liquid reactors. The mass transfer area in a given reactor volume can be varied over several orders of magnitude by the choice of operating parameters. The way in which the volume‐specific conversion can be altered by variation of the volume‐specific mass transfer area depends upon the rate of the chemical reaction. The greater the volume‐specific mass transfer area chosen, the more power is required per unit reactor volume. Analysis shows that not only the attainable conversion but also the yield can be greatly influenced by the volume‐specific mass transfer area. This applies both to parallel and to consecutive reactions. In the case of consecutive reactions, the liquid retention time must also be included as a parameter in yield determination. If a reactor system requires economic optimization, then, in addition to the yield, the power required for mixing and the investments in reactor volume are also of importance. All three parameters can be modified by means of quantities accessible to the engineer, such as gas throughput, specific power dissipation, and residence time. The quantitative relations depend upon reactor type. The relation between these parameters can be plotted quantitatively in a working diagram for each reactor type. Its plotting and use in reactor optimization on the bases of laboratory experiments are considered.
Schwingungen im Chemiebetrieb
Authors: Gaube Erwin 
Published: December 2004

AbstractVibrations in chemical engineering. In the planning of plant attempts are made from the very beginning to eradicate potential causes of vibration by calculation and special design. Experience gained in the commissioning of new plant however, has shown that this aim is not always successful. Usually the causes of vibration have to be found and suitable remedial measures taken to counteract them, but this often proves very time‐consuming. The present article deals with the vibrations met with in practice by the author and gives an overview of the general causes of vibrations occurring in chemical plant.
Verfahren und Kosten der Agglomeration
Authors: Herrmann Walter 
Published: December 2004

AbstractAgglomeration processes and costs. After an introduction to the various means of agglomeration, the function of agglomerating equipment and processes is explained with the aid of diagrams. Focal points are pelleting by drum and pan and compaction with pelleting and roll presses. The capacity and agglomerate properties obtained, e. g. size, porosity, and strength, are discussed.The costs of agglomeration are considered in the light of examples taken from the available literature. It was thus found that pan granulation is cheaper than drum granulation. Up to certain moisture contents, wet granulation can compete with dry compacting.
Der Bio‐Hochreaktor — eine biologische Abwasserreinigungsanlage in Hochbauweise
Authors: Leistner Gerhard , Müller Gerhard , Sell Günther , Bauer Alexander 
Published: December 2004

AbstractThe Bio‐tower reactor – a tower‐type biological waste water purification plant. A novel biological wastewater purification plant is presented which has been developed from the viewpoint of space‐saving and which in comparsion to conventional plant shows more structural similarities with tank assemblies. The developments leading to the construction of the bio‐tower reactor are first described and the fundamental concepts of the constructional engineering and gassing technique involved are outlined. The construction and operational behaviour of the plant are dealt with and the results regarding sludge separation, gassing technique, and space loading are discussed.
Das Oxitron‐System, ein neues biologisches Abwasserreinigungs‐Verfahren für den BSB5‐Abbau sowie zur Nitrifikation und Denitrifikation
Authors: Becker Klaus‐Peter 
Published: December 2004

AbstractThe oxitron system: a new biological sewage treatment process for reducing BOD5 and for nitrification and denitrification. In the oxitron process, the waste water passes through a fluidized sand bed. As in the case of droplets, a stable biological slime is formed on the sand particles. The particular efficacy of the process can be explained in terms of the high specific surface, of the order of more than 3000 m2 per m3 reactor volume. This leads to a particularly effective use of available space. The high content of biomass makes the process largely insensitive to fluctuations in feed rates and toxic effects. The oxitron process is used as a biological purification stage for reducing BOD5 or as the third purification stage for nitrification and denitrification. The reactor can be operated at particularly high solids concentrations (ca. 20 g/l). The correspondingly high oxygen consumption of this process requires the use of pure oxygen in the aerobic step; over 90% of the oxygen supply is utilized. The special advantages of the oxitron process are: (1) 30% lower capital costs than for conventional processes (operating costs are comparable); (2) space requirements are some 80% lower than for the best conventional technology presently available, facilitating expansion; (3) the mode of operation is extremely simple and is not subject to interference by blockages, etc. Design data and results for large scale test plant are reported.
Einsatz von mathematischer Simulation und Miniplant‐Technik in der Verfahrensentwicklung
Authors: Greß Dieter , Hartmann Horst , Kaibel Gerd , Seid Bernhard 
Published: December 2004

AbstractUse of mathematical simulation and miniplant techniques in process development. An integrated study of synthesis and workup or of entire processes is often required in the development of chemical processes. This leads to a large number of possible solutions, of which the most economic one must be selected. This variety can only be mastered at reasonable expense with the aid of present‐day techniques. Examples are presented to show how just a few economic possibilities can be selected and optimized from the plethora of alternatives in simulation calculations based on just a few properties of the materials involved. Economics is the basis of all evaluation. Use of miniplants is considered in the second part of the article, and costs and time‐expenditure are compared with those for industrial pilot plants. Planning and evaluation of experiments raise the effectiveness of this empirical work. Problems of scale‐up are considered, and the advantages of physico‐chemically sound scale‐up models are demonstrated.
Herstellung von Glasfasern für die optische Informationsübertragung
Authors: Grabmaier Josef Gabriel , Aulich Hubert Alfred 
Published: December 2004

AbstractProduction of glass fibres for optical communications. Optical communications requires lightguide glass fibres with low absorption and scattering losses. A brief description of the principal criteria of light conduction in these fibres is followed by an account of present‐day methods of producing highly pure glasses and fibres. These techniques yield fibres of several kilometers in length with a light attention of about 1 dB/km.
Laborreaktoren für heterogene Gasreaktionen — Neue Entwicklungen
Authors: Löwe Arno 
Published: December 2004

AbstractLaboratory reactors for catalytic gas‐solid reactions – new developments. Some laboratory reactors for catalytic gas‐solids reactions are scaled‐down versions of commercial units. Though substantial effects of heat and mass transfer frequently also have to be considered, kinetic and other pertinent data may be gained by refined computational methods. Other types of laboratory reactors are highly spezialized apparatus for gathering kinetic data under carefully controlled conditions. More recent developments are intended to increase the efficiency of rate measurements by applying dynamic methods or by simultaneously observing related phenomena. The topics of the present review are the nonisothermal fixed bed reactor with special regard to axial heat conduction, the nonisothermal catalytic tube wall reactor, and the recycle reactor with controlled concentrations.
Zum Stand der Schwefelsäure‐Produktion
Authors: Becker Hans Jürgen , Gösele Wilhelm , Neth Norbert , Adlkofer Jürgen 
Published: December 2004

AbstractSulphuric acid production – state of the art. Apart from pyrites and other metal sulfides, sulphur is mainly used today as raw material for the production of sulphuric acid. The oxidation of roaster gases or sulphur combustion gases is performed almost exclusively in multistage reactors over catalysts containing vanadium pentoxide. SO2 conversions of more than 99.5% are achieved by intermediate absorption of SO3 (“double catalysis”) and by using efficient catalysts. To further improve the economics of the manufacturing process, new technologies are being tried out, and attempts are being made to develop even more active catalysts. Although there is still some uncertainty regarding the kinetics of SO2 oxidation, empirical findings can be explained quite satisfactorily with existing models.
Anwendungsmöglichkeiten und Einsatzgebiete von Strahlpumpen
Authors: Wagner Gerhard 
Published: December 2004

AbstractApplications of jet pumps. Nowadays jet pumps are economically used in many branches of industry. The versatility of these simply constructed devices is demonstrated for the various kinds of jet pumps. The construction and mode of operation of the pumps is briefly explained, and those advantages which have ensured a wide acceptance of these pumps are presented. Moreover, reference is made to fundamental publications concerned with the design and computation of jet pumps.
Sichere Chemieanlagen – eine ständige Herausforderung an die Technik
Authors: Schlachter Hans 
Published: December 2004

AbstractSafe chemical plants – a constant challenge to technology. The general public is increasingly questioning the safety of industrial plants. In the field of chemistry, in particular, the impression is being evoked that especially serious and continually increasing risks are in evidence in chemical plants. To begin with, the present report proves by means of statistical data that such portrayals are not in keeping with the facts. Then the safety concept in the planning and operation of chemical plants is discussed. With the aid of examples the ceaseless and successful endeavours towards achieving ever greater safety are described. Examples from the field of systematic research in industrial safety are also cited. Finally, the report deals with the plant operators' own responsibility, and cooperation with supervisory bodies and governmental control organizations.
Industrielle Anwendung von zeolithischen Katalysatoren beim Hydrocracken
Authors: Gallei Ewald 
Published: December 2004

AbstractIndustrial application of zeolitic catalysts in hydrocracking. For maximum production of gasoline by hydrocracking using zeolite type catalysts two cracking schemes are presented and the operation conditions, feedstocks, yields, and material balances are discussed. The advantages of zeolitic hydrocracking catalysts are outlined. The main catalyst parameters controlling activity and selectivity are described and a scheme for the preparation of zeolitic catalysts is given, which illustrates the superiority of zeolitic hydrocracking catalysts over amorphous ones. Finally, the hydrocracking of residues is reviewed and a typical process together with the product characteristics and yields obtained is described.
Statische Mischer und ihre Anwendung
Authors: Pahl Manfred H. , Muschelknautz Edgar 
Published: December 2004

AbstractStatic mixers and their applications. Static mixers are generally made up of similar, fixed mixing units installed at right angles to each other in series along a tube or a channel. The energy of mixing is extracted from the flow. Twelve different units are presented. The mixing effect in static mixers under conditions of laminar flow is accomplished either by specially designed feed systems, by cutting and twisting, by displacement and distortion, or by separation and expansion. Depending upon the mixer, very different lengths are required to achieve the same degree of homogeneity. Compared with an empty tube, the pressure drop in static mixers is some 7‐to 200‐fold greater for laminar flow and 100‐ to 600‐fold greater for turbulent flow. Static mixers are employed in all areas of chemical engineering for homogenization, for reduction of the resisdence‐time spectrum, and for heat exchange. Since maintenance and wear are negligible, since incorporation frequently requires no extra space, and since they can be used over wide ranges of viscosity, static mixers are being increasingly employed in continuous processes.
Zerstäuben von Flüssigkeiten
Authors: Schmidt Paul , Walzel Peter 
Published: December 2004

AbstractAtomization of liquids. The process of droplet formation can be represented quite clearly with the aid of dimensionless factors. Thus, clear distinction can be made between dripping, spluttering and atomization for the flow of a liquid through nozzles. In the first two cases laminar flow dominates; droplets of a definite size are formed. Atomization, on the other hand, is conversion of a jet in a turbulent state of flow into a fine spray of droplets covering a wide size range. The most commonly used atomization apparatus include one‐and two‐substance jets, rotation atomizers, and special purpose jets.
Phasengleichgewichte binärer Kohlenwasserstoff‐Gemische
Authors: Wozny Günter , Cremer Helmut 
Published: December 2004

AbstractSieben Verfahren zur Berechnung des Phasengleichgewichts binärer Gemische aus Dampfdruckdaten wurden programmiert, umfassend untersucht und die Ergebnisse von Berechnungen für Kohlenwasserstoff‐Gemische diskutiert. Es handelt sich um ein Regressionsverfahren und sechs iterative Verfahren auf der Grundlage der Gibbs‐Duhem‐Gleichung. Die iterativen Verfahren benötigen die Approximation der experimentellen Dampfdruckdaten z. B. mittels cubic splines oder orthogonalen Polynomen. Für die weitere praktische Anwendung der Ergebnisse, z. B. für die Simulation von Trennkolonnen, ist nach der iterativen Lösung der Gibbs‐Duhem‐Gleichung die Regression der Dampfmolenbrüche notwendig.
Adsorption aus der Gasphase — Grundlagen und Verfahren
Authors: Kast Werner 
Published: December 2004

AbstractFür die Auslegung eines Adsorptionsverfahrens werden Angaben über das Gleichgewicht und die Kinetik benötigt, die in die Massen‐ und Energiebilanzen eingehen und die Durchbruchskurve, d. h. das Beladungsende eines Festbettadsorbers, bestimmen. Die neueren Erkenntnisse über Gleichgewicht und Kinetik vor allem bei der gleichzeitigen Adsorption mehrerer Komponenten und die Auswirkungen des nichtisothermen Ablaufs der Adsorption werden vorgestellt. Die Durchbruchskurve kann auch heute nur unter einschränkenden Bedingungen analytisch berechnet werden, doch sind die physikalischen Einflußfaktoren quantitativ erfaßt und eine – wenn auch aufwendige – numerische Berechnung möglich. Damit ist die Auslegung eines Adsorptionsverfahrens mit einem Aufwand und einer Genauigkeit möglich, die vergleichbar anderen thermischen Trennverfahren sind.
Sonderverfahren der Beseitigung industrieller Abfälle – ihre Auswirkungen und Entwicklungstendenzen
Authors: Schmitt‐Tegge Jan D. 
Published: December 2004

AbstractDie Menge der Sonderabfälle hat abgenommen. Grund: Steigende Beseitigungskosten und steigende Preise für Rohstoffe und Energie. Daraus folgt die Tendenz zur Wiederverwertung oder zu abfallarmen Technologien. Die Verfahren der Tiefversenkung, Einkapselung und Verfestigung, Verbrennung auf Hoher See und Einbringung/Verklappung auf Hoher See werden behandelt. Die zukünftige Entwicklung in der Bundesrepublik hinsichtlich der Abfallbeseitigung auf Hoher See wird aufgezeigt.
Die Automatisierung von Chemieanlagen mit Mitteln der Systemtechnik – Analysen und Trends
Authors: Schmitt Karlheinz 
Published: December 2004

AbstractDie Automatisierungstechnik mit Systemen konnte sich durch die sehr großen Fortschritte der Mikroelektronik entwickeln. Unabhängig davon führt eine veränderte wirtschaftliche Situation in der Chemie, die sich durch höhere Qualitätsanforderungen charakterisieren läßt, zu erweiterten Automatisierungszielen, die zu ihrer Lösung wiederum systemtechnische Methoden erfordern. Damit schließt sich ein Kreis, in den noch eine Organisation der für die Automatisierung verantwortlichen Abteilungen und darauf abgestimmte Konzepte, Lösungen und weiterentwickelte Ingenieurmethoden einzubeziehen sind.
Die Bildanalyse als modernes Verfahren der Partikelmeßtechnik
Authors: Hermes Karl , Kesten Ulrich 
Published: December 2004

AbstractDas Ermitteln von Partikelgrößenverteilungen und morphologischen Eigenschaften disperser Feststoffe im Partikelgrößenbereich zwischen wenigen ßm und mehreren mm in sehr kurzer Zeit läßt sich bei Verwendung eines einzigen physikalischen Meßverfahrens nur mit dem mittelbaren Zählverfahren der Bildanalyse durchführen. Soll ein Bildanalysegerät mit anderen modernen Verfahren zur Partikelgrößenanalyse, z. B. Streulicht‐ und Beugungsspektrums‐Meßgeräten, auch von der Analysenzeit und der aus statistischen Gründen notwendigen Partikelanzahl von > 105 konkurrieren können, muß es in der Lage sein, diese Aufgabe vollautomatisch zu bewältigen. In dieser Arbeit, die als Einführung in das Gebiet der Bildanalyse konzipiert ist, werden daher Meßprinzip und Aufbau von automatischen Bildanalysesystemen beschrieben. Die wichtigsten Elemente werden näher auf ihre Eignung zur Partikelgrößenanalyse hin untersucht, wobei auf die besonderen Bedürfnisse des als Anwender auftretenden Ingenieurs Rücksicht genommen wird. Am Schluß der Arbeit wird das wichtige Problem der Probenvorbereitung für die Bildanalyse erörtert, und es werden Präparationstechniken für spezielle Anwendungsfälle beschrieben.
Entwicklungstendenzen in der Technik katalytischer Fluid‐Reaktionen
Authors: Dialer Kurt 
Published: December 2004

AbstractDevelopment trends in catalytic fluid reactions. Problems associated with raw materials, energy, and the environment have had many repercussions on the industrial development of catalytic processes. Apart from efforts to increase the use of coal‐based feedstock such as synthesis gas and methanol, particular attention is focussed upon improvements in the selectivity of industrial reactions. There appears to be a reversal of direction in the choice of phase: proven homogeneous catalysts are being heterogenized, and heterogeneous catalysts are being employed in homogeneous or liquid form. Other typical features are increased efforts to replace conventional multistep syntheses by direct syntheses, and high pressure syntheses by medium or low pressure syntheses. Finally, measures designed to regenerate or conserve catalytic activity and selectivity are becoming more and more important.
Zur Auslegung von Strahlsaugern für einphasige Stoffsysteme
Authors: Henzler Hans‐Jürgen 
Published: December 2004

AbstractDesign of ejectors for single‐phase material systems. The principal design data of self‐priming jet devices are presented. A theoretical design model is first discussed which provides a good description of the experimental results reported in the literature. Application of this model requires introduction of empirical parameters which depend solely upon geometry and have been determined for various ejector types from experimental results. An energetic comparison permits estimation of the influence of the individual geometrical parameters on the efficiency. This leads to the concept of an energetically favourable device whose efficiency and suction characteristics are given over a wide range of throughput.
Metallvergütung durch Ionenstrahlen
Authors: Wolf Gerhard K. 
Published: December 2004

AbstractFinishing of metals by ion beams. For many years ion beams have been used for doping semiconductors. Recently more and more interest has been shown in them as a method for the finishing of metals. The insertion of an alloying element as an energetic ion into a 0.1 to 1 μm thick surface layer of a metal instead of bulk alloying is interesting, especially with respect to a future shortage of resources. In addition, the ion beam techniques (ion implantation and ion beam mixing) provide the possibility of implanting any element in nearly any substrate. This may often lead even to metastable or amorphous surface structures. In this paper the ion beam techniques are described and the resulting materials are outlined. The possibilities for applications in different fields such as corrosion, mechanical surface properties (tribology), and catalysis are illustrated with examples. They range from pure basic science and applied science to potential procedures to be used in industrial production.
Substratspezifische Stoff‐Führung bei anaeroben Verfahren zur Methan‐Gewinnung
Authors: Baader Wolfgang 
Published: December 2004

AbstractPrinciples of material flow in anaerobic methane production processes. Rising prices of fossil energy are upgrading the importance of processes for generating fuels from organic wastes and from renewable biomass. Anaerobic digestion is a suitable approach for the production of fuel gas rich in methane from wet or liquid organic feedstock. Depending upon the biochemical characteristics of the digestion process and upon the physical conditions for an optimal mass transport, specific technical solutions have been found for treating typical substrates differing in chemical composition, digestability, and fluid mechanical behaviour; such substrates are waste water, sludges, and organic solids with a high liquid content. A survey is given on the principal systems now used for conducting material to be digested through the whole process and in particular through the bioreactor.
Saubere Luft – technische Möglichkeiten, wirtschaftliche Konsequenzen
Authors: Reh Lothar 
Published: December 2004

AbstractClean air – technical possibilities and economic consequences. Starting from the historical development of measures for maintaining clean air in the course of the industrial revolution, the article outlines advances in dust removal which have been accomplished in close, trusting cooperation between legislature, experts and plant operators. The interactions between mankind, technically modified and natural environment, and atmosphere, which have arisen as a consequence of the growth in population, are described and an attempt is made to assign the principal contaminants in the atmosphere to their causers on a global and a national basis. The relationship between rational use of energy and clean air maintenance becomes clear. Additive and integrated air purification procedures are explained with the aid of environmental protection measures adopted in coal‐fired power plant and the costs of excessively low emission level demands pointed out. Examples of gas purification plant in the cellulose industry and the printing trade illustrate the possibilities offered by recycling.
Tropfenabscheider
Authors: Bürkholz Armin 
Published: December 2004

AbstractDroplet separators. Droplet separators are widely used for purification of process and exhaust gas streams. These separators must be of optimum design to keep the necessary investment and operating costs within limits. This requires a good knowledge of both the droplet size and the fractional degree of deposition of the equipment employed. Extensive studies performed in the past decade have permitted practicable solutions to be found for most of the separation problems involved. Use of suitable parameters provides as means of largely reducing the extensive data to simple deposition formulae.