bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gasreinigungsverfahren für große Wasserstoff‐Mengen
Authors: Werner Dietmar 
Published: December 2004

AbstractWasserstoff wird schon heute weltweit in sehr großen Mengen erzeugt. Seine Bedeutung wird mit der Umstellung der Energiewirtschaft vom Erdöl zu anderen Energieträgern noch wachsen. Es wird eine Darstellung und kritische Betrachtung der vorhandenen Technologien zur Reinigung von Wasserstoff gegeben unter besonderer Berücksichtigung neuer Entwicklungen wie der Druckwechsel‐Adsorption und der Diffusion an synthetischen Hohlfasern.
Konzeption und Wege des Explosionsschutzes
Authors: Steen Henricus 
Published: December 2004

AbstractAufbauend auf dem Wahrscheinlichkeitsprinzip wird die „Philosophie”︁ des heute angewendeten Explosionsschutzes beschrieben. Grundlagen und einschränkende Bedingungen des primären Explosionsschutzes (Vermeidung gefahrdrohender Mengen explosionsfähiger Gemische) werden dargelegt. Der Umfang des sekundären Explosionsschutzes (Vermeidung von Zündquellen) richtet sich nach der ortsabhängigen Wahrscheinlichkeit des Auftretens explosionsfähiger Gemische, die zur Festlegung explosionsgefährdeter Bereiche und zu deren Einteilung in Zonen führt. Mögliche Rückwirkungen der zu erwartenden Explosionsschäden auf die Zoneneinteilung werden erläutert.
Medizinische Verfahrenstechnik
Authors: Chmiel Horst 
Published: December 2004

AbstractViele verfahrenstechnische Grundvorgänge beruhen auf Transportvorgängen, z. B. aufgrund vorhandener Temperatur‐, Druck oder Konzentrationsdifferenzen. Diese Transportvorgänge finden vielfältig im gesunden Kreislauf statt. So liefern Verbrennungsprozesse dem menschlichen Körper die erforderliche Wärme. Das Herz als Blutpumpe sorgt für eine optimale Durchströmung aller Gefäße. In der Niere erfolgt an hochkomplizierten biologischen Membranen durch Stoffaustauschprozesse eine Entgiftung des Blutes.Es liegt daher nahe, den Verfahrensingenieur für die Lösung einer Vielzahl in der Medizin auftretender verfahrenstechnischer Probleme heranzuziehen. Typische Aufgaben sind: Charakterisierung des Fließverhaltens von biologischen Fluiden, die Erforschung der Wechselwirkungen zwischen Blut und körperfremden Materialien mit dem Ziel, für den temporären oder permanenten Einsatz geeignete Werkstoffe zu finden, oder die Entwicklung von Blutpumpe, künstlicher Lunge, künstlicher Leber und künstlicher Niere.
Gütesicherung bei Fertigung und Montage von Rohrleitungen
Authors: Fiehn Harald 
Published: December 2004

AbstractBei Fertigung und Montage von Rohrleitungen müssen außer den situationsbedingten und sachlichen Fehlerursachen auch die verhaltensbedingten Fehlerquellen berücksichtigt werden, damit die technische und menschliche Fertigungssicherheit im notwendigen Umfang gewährleistet werden kann. Behandelt werden hierbei folgende Einzelheiten: Bestellangaben, Fertigungsangaben, Fachpersonal, Fertigungseinrichtungen, Kontrollschritte zur Absicherung des Fertigungserfolges und Kontrollumfang in Abhängigkeit von der erforderlichen Qualitätsstufe. Mehrjährige Aufschreibungen über Fehlerquoten bei Rohrleitungsschweißarbeiten dienen zur Diskussion des notwendigen Kontrollumfangs. Die entstehenden Kontrollkosten werden für die Modellfälle personenbezogene Überwachung und objektbezogene Überwachung gegenübergestellt. Auf typische Ausführungsfehlerwird hingewiesen. Praxisbewährte Arbeitsrichtlinien sind vorhanden und enthalten auch eindeutige Qualitätsanforderungen. Die Basisunterlagen für eigenverantwortliches Handeln stehen somit zur Verfügung.
Ausbreitung von Abgasfahnen
Authors: Schönbucher Axel , Scheller Volker 
Published: December 2004

AbstractZur Ausbreitung luftfremder gasförmiger Stoffe in der Atmosphäre werden die wichtigsten experimentellen Untersuchungsverfahren sowie wesentliche mathematische Modellvorstellungen besonders von Gauß‐Modellen dargelegt. Dabei wird insbesondere die Einwirkung der von meteorologischen Einflüssen geprägten konvektiven und turbulenten Eigenschaften der Atmosphäre auf die Ausbreitung von Abgasfahnen behandelt. Ein äquidensitometrisches Meßverfahren hat gezeigt, daß die Langzeitstrukturen einer Raffinerie‐Rußfahne im norddeutschen Raum mit einem Gauß‐Fahnenmodell quantitativ beschrieben werden können. Hieraus ergeben sich die für alle Ausbreitungsmodelle fundamentalen Streuungsparameter bzw. Austauschgrößen, deren Entfernungsabhängigkeit und Größenordnung aus der äquidensitometrischen Ballenstruktur der Abgasfahnen verständlich wird.
Biokältetechnik: Verfahren der Gefrierkonservierung in der Medizin
Authors: Scheiwe M. W. , Rau G. 
Published: December 2004

AbstractDas Verfahren der Gefrierkonservierung beinhaltet die Überführung der flüssigen Substanz in eine feste, gefrorene Phase und die Umkehr dieses Vorganges. Das Ziel ist die möglichst vollständige Erhaltung der Ausgangseigenschaften des biologischen Materials, insbesondere der Lebensfähigkeit und der Ausbeute lebender Zellen, wie z. B. Blutkörperchen, die in der Medizin gezielt therapeutisch verwendet werden sollen. Diese Arbeit soll exemplarisch den Weg aufzeigen, der von der gestellten Aufgabe zur verfahrenstechnischen Lösung führt. Anhand der Physikochemie des Gefriervorganges der vorliegenden Kochsalzlösungen und involvierten, osmotisch reagierenden Zellen werden die Bedingungen für günstige Prozeßführung und die geschwindigkeitsbestimmenden Schritte dargelegt. Die hieraus folgenden technischen Problemstellungen sind Wärmetransport an Flüssig‐Stickstoff, instationäre Wärmeübertragung gefrierender Körper und Auslegungskriterien für technisches Gefrieren. Schließlich werden Gefrier‐Konservierungsprozesse und Ergebnisse der besonders aktuellen Anwendungsgebiete, nämlich rote Blutkörperchen für Katastrophenfälle und weiße Blutkörperchen für die Krebstherapie, aufgezeigt. Als konkretes Beispiel wird eine erst durch die Gefrierkonservierung ermöglichte Verbesserung der Tumortherapie aufgezeigt.
Der Ethylenoxid‐Prozeß und die Regenerierung des dabei verwendeten Silber‐Katalysators
Authors: Rebsdat Siegfried , Mayer Sigmund , Alfranseder Josef 
Published: December 2004

AbstractEthylenoxid ist ein bedeutendes Zwischenprodukt der chemischen Industrie und wird durch Direktoxidation von Ethylen mit Sauerstoff über einem Silber‐Trägerkatalysator gewonnen. Die bei diesem heterogen katalysierten Prozeß eingesetzten Silber‐Katalysatoren unterliegen einer Alterung, so daß sie in bestimmten Zeitabständen in einem ums‐tändlichen Verfahren ausgetauscht werden müssen. Die Alterung der Katalysatoren verursacht deshalb hohe Kosten und Materialverluste. Das hier beschriebene Verfahren bietet alternativ die Möglichkeit zur Regenerierung von gealterten Silber‐Katalysatoren durch eine Imprägnierung mit Cäsium. Dadurch werden erhebliche Einsparungen sowohl an den Einsatzstoffen Ethylen und Sauerstoff als auch am Katalysator‐Material erzielt. Das Verfahren hat sich mittlerweile in zahlreichen großtechnischen Anwendungen bewährt.
Stofftrennung durch Membranen
Authors: Rautenbach Robert , Albrecht Rainer 
Published: December 2004

AbstractSeparation by membranes. The paper reviews membrane processes in general, excluding the electro‐membrane processes. The authors' aim is to discuss the aspects common to all membrane processes as well as the essential differences between them. The following processes will be examined: Reverse osmosis, ultrafiltration, gas permeation through porous or diffusion type membranes, pervaporation and liquid membrane techniques. In liquid systems, mass transport at the membrane surface proves to be the limiting factor. Conditions on the permeate side tend to influence flux and quality of the permeate only when a considerable pressure drop occurs. A typical example is that of hollow‐fiber modules. It is shown how the permeability and dimensions of the membrane require selective adjustment in order to establish maximum flux.
Sauberes Wasser – technische Möglichkeiten, wirtschaftliche Konsequenzen
Authors: Lipphardt Günter 
Published: December 2004

AbstractClean water – technical possibilities and economic consequences. Water pollution by industrial effluent is becoming more and more of a political warcry which creates a fear of technology – precisely that technology which is largely responsible for the present quality of life. It has so far gone largely unrecognized by the public that industry and municipal authorities have accomplished a great amount in the area of waste water purification. The versatile techniques developed in recent years are summarized, and biological purification is treated in somewhat greater detail. Annual investment in waste water treatment runs at several thousand million DM, and represent a considerable financial burden on industry and municipal authorities. The thesis that economic considerations should play no role in environmental protection is not acceptable in that unqualified form, and would mean that German industry would no longer be competitive in an international arena. Ecological demands cannot be separated from economic considerations. All participants will have to make some compromises on our way to our desired goal of a flourishing economy in an almost intact environment.
Saubere Umwelt – eine gesellschaftliche Aufgabe
Authors: Feldhaus Gerhard 
Published: December 2004

AbstractA clean environment – responsibility of society. The need for environmental protection was previously beyond question and is more so than ever today. Discussions or controversy centers on the extent of measures needed to protect our environment. Such discussion is conducted by pressure groups while decisions are made by society for environmental protection is a function of society. Whereas the aversion of danger was formerly the main consideration prevention is becoming increasingly important. The potential dangers have been essentially eliminated. It is our present task to ensure living space for future generations and to preserve space for tomorrow's industry. This is possible only with the aid of technology, provided that technologists are prepared to adopt new approaches. We must do away with a mere technology of reduction, i. e. peripheral environmental protection. Tomorrow's task is integrated invironmental protection.
Verfahrenstechnik der Kohlehydrierung in Sumpfphasen‐Reaktoren
Authors: Kürten Heribert 
Published: December 2004

AbstractChemical engineering of coal hydrogenation in sump phase reactors. The science of chemical engineering was still in its infancy when the hydrogenation of coal was developed from 1924 onwards at Ludwigshafen, Rhineland. The term backmixing, for example, was unknown. Nevertheless, the scale‐up from a pilot to a production reactor was performed correctly at that time. Even with today's knowledge, the IG Farben sump phase reactors could not have been better designed. Almost four decades have meanwhile elapsed since the cessation of coal hydrogenation in Germany (1945). Nowadays high pressure reactors having more than 50 times the volume of the IG reactors can be produced. Considerable advances have also been made in measurement and control engineering. Hence new chemical engineering questions and solutions arise. If coal hydrogenation is to be performed on a significant industrial scale in 10 to 20 years, this will be economically feasible only by exploiting the possibilities of large reactors having a throughput of 1 to 3 million tons of coal per annum.
Verfahrenstechnische Auslegungsunterlagen für Rührbehälter als Fermenter
Authors: Henzler Hans‐Jürgen 
Published: December 2004

AbstractEngineering design data for agitator vessels as fermentors. The article develops and collects design data for stirring vessels for calculation of mass and heat transfer and the flooding point and stirrer power requirements for aerated liquids. The data refer to low‐viscosity, higher viscosity, and structure viscosity liquids with difering coalescence behaviour. The working data presented are used to derive results for a specific system (air/aqueous solution of carboxymethylcellulose) which illustrate decisive relationships and limitations arising from mass and heat transfer. There results important information for the operation, and choice, and scale‐up of stirred fermentors.
Auslegung und Maßstabsvergrößerung von Kristallisatoren
Authors: Mersmann Alfons 
Published: December 2004

AbstractDesign and scale‐up of crystallizers. Industrial scale crystallizers have to be designed in such a way that the crystalline product has the design particle size distribution, crystal form, and purity. Data on multiphase flow, solubility, balances of mass, energy, and number of crystals, kinetics (crystal growth rate and nucleation rate), and heat transfer are required. The present article discusses problems of kinetics in greater detail than other aspects. Multiphase flow is considered only briefly and heat transfer not at all. Familiarity with the terms homogeneous and heterogeneous (primary) and secondary nucleation [1, 2] is also assumed. This contribution is based on evaluation of available literature.
Rohrleitungstechnik und Verfahrenstechnik
Authors: Gelbe Horst 
Published: December 2004

AbstractPipework engineering and chemical engineering. Piping must be included as an essential part of a plant in the chemical engineering design of the process units. The necessary engineering specifications for an appropriate, minimum cost design of pipe systems and the job integration of pipe planning, which demonstrates the strong links between pipework engineering and chemical engineering in the planning and construction of plant, are discussed. The use of computers in pipe engineering began about 12 years ago. Development proceeded via computer mass listings, computer‐plotted isometric drawings, automatic material listings to the contemporary computed plotted flow charts, leading to increasing confrontation of chemical engineers with these programs with repercussions in their work. A report is presented on the development of new systems and on the present state of implementation of these computer methods; the scope and limitations are indicated.
Anlagentechnische Entwicklungen zur Erhöhung der Sicherheit
Authors: Friedel Lutz 
Published: December 2004

AbstractPlant engineering developments for improvement of safety. Research undertaken in various companies for reliable dimensioning of production equipment to withstand dangerous pressure increases, e. g. as a result of a runaway reaction or a dust explosion, is presented. Measures for the safe removal of the reaction materials are discussed.
Fortschritte in der Zerstäubungstrocknungs‐Technologie
Authors: Hein Jean‐Claude , Rafflenbeul Rolf , Beckmann Manfred 
Published: December 2004

AbstractProgress in the technology of spray drying. Stringent quality demands on spray‐dried goods have led to increasing use of nozzle spray dryers. In contrast to disk spray dryers, nozzle dryers yield microgranules and low‐dust products directly. Although the process of nozzle spray drying is over 50 years old, the volume of available calculation material necessary for general application is sparse and limited mainly to special products or problems. This article presents new advances in the technology of nozzle spray dryers. An analytical formulation of the drying of a drop within the first drying phase decisive for granulation constitutes the basis of the general applicability of the fresh insights gained.
Fertigungstechnische Probleme beim Einwalzen und Schweißen von Rohren in Rohrböden bei Wärmeaustauschern
Authors: Vollhardt Frohmut 
Published: December 2004

AbstractProduction problems in the rolling‐in and welding of tubes in the tube plates of heat exchangers. One of the principal problems besetting the construction of equipment is the mutual sealing of pressurized spaces. These sealing problems governed design for many years and remained virtually stagnant for decades. New chemical processes involving maximum thermal flux densities compelled engineers to produce new designs. Further problems were those of high and low‐temperature corrosion and attack by erosion which required mastering by design measures. The historical development of design constitutes the basis of the paper. The following topics are considered: (1) Rolling‐in and welding techniques; (2) automated welding in nuclear power plant construction (demands placed on seam tube/deposit welding; special demands on production techniques); (3) quality assurance (quality planning, quality control, checking measures, destructive testing, procedures adopted in case of deviations, quality analysis, documentation).
Werkstoff‐ und Schweißfragen bei der Herstellung von dickwandigen Druckbehältern für höhere Betriebstemperaturen aus Stählen mit 2 bis 3% Chrom und ca. 1% Molybdän
Authors: Grote Günter 
Published: December 2004

AbstractMaterials and welding in the production of thick‐walled pressure vessels for elevated operating temperature made of steels containing 2 to 3% of chromium and ca. 1% of molybdenum. High‐temperature steels containing 2 to 3% of chromium and ca. 1% of molybdenum are resistant to hydrogen under pressure at temperatures up to about 500°C. Being readily weldable, they are excellently suited for high pressure equipment in chemical plant construction. Their tendency to embrittlement at operating temperatures of 400 to 500°C is a drawback. However, specific metallurgical measures adopted during the production of the semifinished material and the welding materials, and use of optimized welding techniques and heat treatment keep this embrittlement within limits. The article reports recent experiences gained in producing pressure vessels with welding seam thicknesses of up to 230 mm at the authors company.
Die Grundlagen der pneumatischen Förderung
Authors: Wirth Karl‐Ernst 
Published: December 2004

AbstractPrinciples of pneumatic conveying. The design of pneumatic conveying systems is critically dependent upon a knowledge of the pressure drop and the minimum necessary velocity of the conveying gas. Starting from the areas of application of pneumatic conveying systems, the conveying states occurring are discussed and appropriately assigned to the diagram of state. The pressure loss equation is reported for conveying in form of a fully suspended flow and strand‐type conveying and the theoretically predicted pressure losses are compared with experimental values for the conveying of coarse and finegrained materials. After mentioning the calculation of the pressure drops due to acceleration and to pipe bends, the article discusses the problem of pipe enlargement for long conveying distances. Equations are also given for the calculation of the so‐called blocking limit and of the conveying gas velocity at which the minimum pressure drop occurs. The influence of the compressor on the choice of the operating point is also discussed. New calculation equations are then given for horizontal and vertical conveying in form of a fully suspended flow conveying and for horizontal strandtype conveying which permit reliable scale‐up. Moreover, a new equation is reported for the blocking limit in horizontal conveying.
Kriterien zur Beurteilung der Zündgefahren infolge elektrostatisch aufgeladener Flüssigkeiten
Authors: Krämer Helmut 
Published: December 2004

AbstractCriteria for the assessment of ignition hazards due to electrostatically charged liquids. The state of the art in the assessment of ignition hazards due to static electrification of liquids is reviewed. Starting from the physical problems of the electrification of streaming or sprayed liquids, the charge accumulation and resulting electrical fields and potentials as well as the question of incendivity of the different types of gas discharges occurring as a consequence of the highly charged liquid, the criteria are presented which allow the assessment of the ignition hazard in practically relevant cases such as tank filling with chargeable liquids, charging resulting from stirring processes and charging of liquid sprays during tank cleaning with liquid jets.
Verfahrenstechnische und wirtschaftliche Aspekte der Verarbeitung verdünnter SO2‐Gase zu Schwefelsäure
Authors: Sander Ulrich , Fattinger Volker 
Published: December 2004

AbstractChemical engineering and economic aspects of converting dilute SO2 gases into sulphuric acid. In the contact process for production of concentrated sulphuric acid the lowest limit for the autothermal processing of dilute SO2 gases lies at around 2 vol.‐% SO2 provided that a pre‐drying concentrating system is in use. Yet more dilute SO2 gases can be processed by Ciba Geigy's nitrogen oxide/sulphuric acid process – a modern version of the well‐known lead chamber process – which is already producing 70 to 75% H2SO4 from molybdenum disulfide roasting waste gases of ca. 1 vol.‐% SO2 on an industrial scale. The paper considers not only the specific boundary conditions, and chemical engineering characteristics of the two fundamentally different processes but considers above all the economics of processing low‐concentration SO2 gases for sulphuric acid.
Sieden — Stabilisator und Störfaktor sicheren Betriebes
Authors: Mayinger Franz 
Published: December 2004

AbstractBoiling – stabilizer and destabilizer of safe operation. Boiling is used in power‐ and chemical engineering if large quantities of energy have to be transported and if high heat‐flux densities have to be applied. The stabilizing action of boiling, which is already high due to the large heat transfer coefficients and small temperature differences, is further improved by the fact that heat transfer still increases with increasing energy addition. Even if single‐phase liquid flow is present under normal operation conditions power fluctuations can be overcome without impermissible temperature rise due to the onset of subcooled boiling. Beyond a critical heat‐flux, however, film boiling starts which decreases the heat transfer coefficient by orders of magnitude. In apparatus in which the fluid is transported under conditions of high void fraction it should be ensured that the liquid film at the wall is thick enough to guarantee a sufficient heat transport. Also, under these conditions boiling can stabilize or destabilize the energy transport.
Aufgabengerechte Informationssammlung für die Verfahrensentwicklung
Authors: Blaß Eckhart 
Published: December 2004

AbstractInformation system for process development. An essential requirement for successful process development is the availability of relevant specialist information. Structuring the necessary activities by the techniques of systems engineering during the course of process development can provide detailed knowledge of the information required. However, comparison of available supply and demand shows that an essential part of the information, i.e. the solutions of unit operations and the accompanying equipment, have not hitherto been collected in systematic information systems. There fore principles are developed for the creation of information systems for process development and are demonstrated by the example of a „solution catalogue”︁ for filter equipments for the solid/fluid separation.
Neue Entwicklungen zur Druckwechsel‐Adsorption
Authors: Richter Ekkehard , Harder Klaus‐Burkhard , Knoblauch Karl , Jüntgen Harald 
Published: December 2004

AbstractNew developments in pressure swing adsorption. Continuing development of the adsorption agents and optimization of the process have permitted solution of new problems of selective separation and isolation of gases from gas mixtures and of gas purification by pressure swing adsorption. While processes have previously been developed in which the product gas is obtained during the adsorption step, more and more processes are now becoming available in which gases of high purity are obtained during the desorption step. After derivation of the fundamental desorption steps, the new techniques are illustrated in the case of the enrichment of CH4, CO2, and ozone, and for recovery of NOx from nitric acid waste gases.