bluuebunny/crossref_metadata_2025_split huggingface dataset:
Naßmahlung in Rührwerksmühlen
Authors: Stadler Reinhold , Polke Reinhard , Schwedes Jörg , Vock Friedrich 
Published: December 2004

AbstractWet grinding in agitated ball mills. To ensure certain product qualities it is necessary to have very fine particles or a narrow particle size distribution. For this process agitated ball mill grinding can be used as well as crystallisation and precipitation. Cost effective grinding of very fine products to a narrow particle size distribution requires that the effects of variation of strain intensity, frequency of impacts, residence time distribution, size of grinding media, viscosity of liquid and concentration of feed material should be known. The most important parameters and their effects on the grinding result are demonstrated, as well as explained by a model, and the consequences for the operating conditions of agitated ball mills are presented. By using small grinding media in agitated ball mills the production rate can be increased, or at the same energy level smaller particles can be obtained by grinding or deagglomeration. At high flow rates and a narrow residence time distribution the feed material becomes more homogeneous. These facts require the development of new or modified types of agitated ball mills.
Kopplung von Reaktions‐ und Kostenmodell: Der Weg zur effizienten Prozeßoptimierung
Authors: Büchs Jochen 
Published: December 2004

AbstractCoupling of reaction and cost model: The efficient approach to process optimization. At present the investigation and optimization of chemical and biochemical reaction processes are still conducted using mostly empirical or intuitive methods. A more systematic and efficient method of process development can be achieved when experimental work is accompanied and guided by mathematical modelling. This is shown for the example of the development of an industrial L‐lysine production process. The guideline for the design of reaction models is presented as a flow sheet and explained in detail using the above example. The great advantage of a complete and verified model will become apparent, especially for reactor scale‐up and for estimation of the effects and possible benefits of advanced reactor configurations, such as fed‐batch or continuous‐flow reactors, including catalyst recycle systems or multi‐stage reactor cascades.
Modellgestütztes Messen in chemischen Reaktoren
Authors: Schuler Hans , Schmidt Christian‐Ulrich 
Published: December 2004

AbstractModel‐aided measurement in chemical reactors. Some reaction‐specific variables of chemical reactors can be determined only with difficulty, sometime only with analytical measurements which are corrupted by time lags. In contrast, the approach tries to determine these variables indirectly and without time delay from easily measured variables like temperatures, pressures, flows. These sensor signals are processed together with reactor models to provide the characteristic reaction variables. This contribution discusses the applications of model‐based measuring techniques to chemical reactors. The systems are applied to operator assistence, process diagnosis, and reactor control. Their operation is submitted to a critical appraisal.
Die Kristallisationstheorie in der Praxis
Authors: Wöhlk Wolfgang , Hofmann Günter , de Jong Esso J. 
Published: December 2004

AbstractTheory of crystallisation in practice. The use and applicability of crystallization theories for industrial crystallization practice are evaluated. The conclusion is that the plant user in particular benefits from the Population Balance Model because it allows for bug diagnostics and prediction of response on altering conditions. Also for design purposes, the available theoretical models greatly helped to increase insight into the wide range of events occurring in a crystallizer and how their interactions govern the resulting product. However, despite the enormous amount of research work done so far, the quantitative application of theoretical models has not found entrance into the design of tailor‐made crystallizers for strictly defined particle size distributions. From a designer's point of view, further investments of time and money should be considered carefully because the actual state of knowledge already allows more than 80% of the encountered problems to be solved. One area of common interest that urgently deserves more attention in the near future is habit modification by additives.
Katalysatoren für den Umweltschutz
Authors: Engler Bernd H. 
Published: December 2004

AbstractCatalysts for environmental protection. The main emitters of anthropogenic air pollution are internal combustion engines, power plants, and production processes. Components of exhaust gases which are regarded as pollutants are hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), and dust. Three main types of catalyst are understood to improve the environment; namely automotive emission control, NOx abatement and oxidation. To reduce the pollutants HC, CO, and NOx in automobile exhaust gas, three‐way catalysts are currently applied. The reduction of particle emissions in diesel exhaust gas is achieved by diesel filters and oxidation catalysts. Pollutants from power plants are mainly the inorganic components NOx and SO2. In the SCR process, NOx is catalytically reduced to nitrogen and water. The DESONOX process is suited for the simultaneous catalytic abatement of NOx and SOx. Exhaust gases from production processes in many areas require after‐treatment. Therefore catalyst formulations depend on process parameters and exhaust gas components. This overview presents and explains catalyst types, design, mode of operation, and processes.
Neuere Entwicklungen und Perspektiven auf dem Gebiet des technischen Kohlenstoffs
Authors: Collin Gerd , Zander Maximilian 
Published: December 2004

AbstractNew developments and outlook for technical carbon. The present world production of technical carbon amounts to 20 Mio. t/a (metallurgical coke as well as petroleum and pitch coke not included). More recent developments in the field of technical carbon are discussed in detail. Topics covered include: production and utilization of technical carbon and graphite products in metallurgy; recent advances in the use of carbon black as reinforcing material for car tyres; the significance of activated carbon for waste gas purification including the recovery of valuable materials; high‐performance materials from carbon such as carbon fibres, carbon composites, and full‐matrix carbons; synthesis of diamond for technical applications; preparation of diamond or diamond‐like films by carbon vapor deposition; structure, preparation, and properties of fullerite, a new form of carbon, and conceivable future applications.
Katalytische Abluftreinigung: Verfahrenstechnische Aufgaben und neue Lösungen
Authors: Eigenberger Gerhart , Nieken Ulrich 
Published: December 2004

AbstractCatalytic air purification; Challenges and new solutions. The integration of regenerative heat exchange into the catalyst bed allows for the autothermal operation of catalytic air purification with a low content of combustible gas. Concentrations corresponding to an adiabatic temperature rise of less then 20 °C can be processed without an additional heat source; in case of higher concentratons a side stream withdrawal allows for the utilization of the total heat of combustion at the highest reactor temperature. The feedback of heat due to the integrated heat exchange gives rise to an unusual reactor behaviour. An analogy of fixed bed reactor operation with countercurrent heat exchange is used to derive simple equations for reactor design and operation. If conventional catalyst packings are replaced by monolithic catalysts, substantial reduction in pressure loss and/or packed bed volume can be obtained. The corresponding relations are briefly discussed.
Produkteigenschaften und Verfahrenstechnik
Authors: Borho Klaus , Polke Reinhard , Wintermantel Klaus , Schubert Helmar , Sommer Karl 
Published: December 2004

AbstractProduct properties and process engineering. The properties of solids are determined by their chemical composition, their state of dispersion, and their interfacial forces. They are largely responsible for the behaviour of the products during the manufacturing process and for the desired quality characteristics of the finished product. The aim of this survey is to illustrate the influence of particle size distribution and interfacial forces on product properties. The effects shown can be explained with the aid of a few physical modes. The first part shows how product properties can be adjusted to achieve a particular aim, principally by modifying the particle size. These include product‐relevant properties such as filtration properties, miscibility, and potential for dust explosion, as well properties relevant to the (final) product such as colour and taste. As the particle size decreases, the forces acting between the particle become increasingly important. The second part of this article therefore focuses on those product properties which can be influenced by way of changes in the cohesive forces. Production‐relevant properties are flow properties, bulk density, agglomeration behaviour; product‐relevant properties are tablet stability and redispersibility of foods, dyes, etc. Among the cohesive forces, capillary forces deserve particular attention. The paper concludes with an account of their role in the manufacture and use of solids. The pore structure of an agglomerated solid is determined by capillary forces and the external forces required during the manufacturing process.
Probleme und Erfahrungen bei großtechnischen Packungskolonnen
Authors: Gann Martin , Kaiser Rudolf , Schoenmakers Hartmut , Zeck Sebastian 
Published: December 2004

AbstractProblems and experience with industrial scale packed columns. Apart from column plates, random and structured packings are being used increasingly as internal components of distillation columns. The advantage of structured packings lies in an enhanced specific separation performance at significantly lower pressure drops than in the case of classical plate columns. In contrast to column plates, there is no defined liquid pathway in random and structured packings; in particular, the dependence upon the initial distribution in columns of large diameter proves to be problematical. Recent theoretical model calculations and laboratory scale studies have shown that the liquid distribution in structured packings is of paramount importance, above all in columns having diameters in excess of 1 m. The present article reports problems and experience gained with industrial scale distillation columns by considering four examples. In addition, the authors also provide an in‐depth account of the factors and problems relating to the assessment of separation performance of industrial columns.
Die Abscheidung von polychlorierten Dioxinen und Furanen aus Abgasen mit Aktivkoksverfahren
Authors: Richter Ekkehard 
Published: December 2004

AbstractRemoval of Polychlorinated Dioxins and Furans from Off‐Gases by Activated Charcoal. Discussions on solid waste incineration are dominated by the formation and emission of polychlorinated dibenzodioxins (PCDD) and dibenzofurans (PCDF). The predominant part of these substances remains in the fly ash, and less than 20% is present in the off‐gases. Very stringent emission limits have been stipulated during recent years in many countries. The adsorption of PCDD/PCDF on carbonaceous materials has proved to be a very effective technique for their removal. Experimental results relating to gas clean‐up, adsorber types, and concepts for the integration in plants are described.
Katalyse in der Abluftreinigung
Authors: Fink Klemens , Gajewski Wolfgang , Joisten Michael , Neufert Ronald , Sprehe Josef , Zürbig Jürgen 
Published: December 2004

AbstractCatalysis in Air Purification. In most cases catalytic purification of waste gas allows the reliable reduction of industrial emission to meet existing regulations. This method can remove numerous organic and inorganic compounds from waste air. This review deals with design, applications and function of such air purification units with special regard to the catalysts used. Furthermore, aspects of chemical engineering relevant for planning and construction are also discussed.
Mittlere Temperaturdifferenz und Wirkungsgrad in mehrgängigen Rohrbündel‐Wärmeübertragern mit und ohne Umlenksegmente
Authors: Gaddis Edward Shafik 
Published: December 2004

AbstractMean Temperature Difference and Efficiency of Multipass Shell‐and‐Tube Heat Exchangers with and without Segmental Baffles. Branched flow in a multi‐passes shell‐and‐tube heat exchanger with segmental baffles causes a reduction in the mean temperature difference and the thermal efficiency of the apparatus compared with a pure counter‐flow. The influence of the shell‐side flow induced by the segmental baffles on the thermal performance of the heat exchanger is mostly ignored. Making certain assumptions (e.g. constant overall heat transfer coefficient) theoretical relations of the thermal performance of the exchanger can be derived from the energy balance and the kinetic equation. If these assumptions are not valid, a numerical integration of the differential equations is necessary. Ignoring the influence of the shell‐side flow induced by the baffles is only possible under certain conditions. If these conditions are not fulfilled, the cell‐method can be used.
Abscheidung organischer Dämpfe
Authors: Börger Götz‐Gerald 
Published: December 2004

AbstractEmissionen organischer Dämpfe aus Industrieanlagen werden durch Vorschriften, z.B. die Technische Anleitung zur Reinhaltung der Luft, Grenzen gesetzt. Zu deren Einhaltung steht ein breites Spektrum von Verfahren zur Verfügung, das in sieben Gruppen gegliedert werden kann: (1) Kondensation, bei hohen Konzentrationen als Teil‐ oder als Vorabscheidung, (2) Adsorption für schlecht wasserlösliche Dämpfe oder bei geringen Konzentrationen, (3) Absorption für wasserlösliche, chemisch zu bindende oder konzentrierte Dämpfe, (4) Membran‐Permeation für einige Fälle konzentrierter Dämpfe, (5) Verbrennung für alle Arten organischer Dämpfe, (6) Katalytische Umwandlung für leicht, ausschließlich zu Gasen oxidierbare Dämpfe, (7) Biologische Oxidation für biologisch gut abbaubare Dämpfe geringer Konzentration. Aus einigen der Verfahren erhält man wiederverwendbare, flüssige Organika. Die übrigen Verfahren müssen so geführt werden, daß Oxidationsprodukte entstehen, die in der Umwelt toleriert werden können.
Nutzung unterschiedlicher Streulichtanteile zur Partikelgrößen‐Bestimmung in dispersen Systemen
Authors: Bauckhage Klaus 
Published: December 2004

AbstractUtilisation of Different Components of Scattered Light for Particle Size Determination in Dispersed Systems. Light scattered by finely and coarsely dispersed particles can be used in variety of ways for characterization of sprays, emulsions, or suspensions. The characteristic of greatest interest is the particle size or the particle size distribution. While homogeneous, coarsely dispersed particles at sufficient dilutions and randomly distributed in a transparent continuous phase are generally amenable to particle size analysis, finely dispersed particles at higher concentrations or coarsely dispersed particles containing finely dispersed components are often difficult to measure. This article discusses ways of overcoming such difficulties on the basis of examples taken mainly from phase Doppler anemometry.
Minimierung von Abgasemissionen aus diskontinuierlichen Produktionsanlagen der chemischen Industrie
Authors: Simon Eberhard 
Published: December 2004

AbstractMinimising Waste Gas Emissions from Batch‐Operated Production Plant in the Chemical Industry. In fulfilling legal obligations to limit waste gas emissions, the strategy of avoidance and reduction has to take precendence over waste gas cleaning. Fundamental disadvantages and limited possibilities of waste gas cleanning systems create a necessity to minimize waste gas emissions by substitution of process materials, or by better encapsulation of process systems. Reduction of process gas emissions is shown by the examples of gas feedback, avoidance of gas pressure cushions, and encapsulating of stirring systems as well as centrifuges. The problem of diffuse emissions from gaskets in separatable connections and from fitting casings is discussed. An example of chemical reaction in a strictly closed system is given. With regard to the reduction of exhaust volumes from open sources, bulk materials feed and sampling are discussed; centrifuges, pressure filters and continuous belt filters are shown as examples of closed systems in solid‐liquid‐separation.
Strukturwandel in der Ingenieurtechnik der chemischen Industrie – Wege zum Partner und Unternehmer
Authors: Francke Diethard , Ochel Klaus P. , Berger Walter , Sommer Ernst , Bode Henning 
Published: December 2004

AbstractStructural Change of Engineering Units in the Chemical Industry – Ways of Becoming a Partner and Entrepreneur. Structural change must not be misunderstood as only observing staffing levels or methods of organisation. On the contrary, the cost/benefit‐relation is much more important. A balanced relation of a company's own personnel and the contractor's has to be considered. Structural change means also change of mind set: The task of management is nowadays to implement a culture of operational profit instead of a culture of demands. It is becoming more and more important to cooperate in a team. This cooperation starts early in defining the project aims, includes analysing all functions, looking for alternatives regarding cost/benefit‐aspects and is based on a clear, structured analysis of the problem instead of quick solutions.
Rechnergestützte Konfigurierung von RI‐Fließbildern am Beispiel von Pumpen
Authors: Blitz Helmut , Engelke Jochen , Sonnenschein Raymund , Schmidt‐Traub Henner 
Published: December 2004

AbstractKnowledge‐based Design of PI Diagrams Exemplified for Pumps in Chemical Plant. To date, computer‐aided design for flow‐sheets has focussed on drawing procedures and reports extracted from these drawings. Today's software technology offers important potential which has still not been fully exploited, e.g. for the design of PI diagrams as front‐end application of CAD systems. PI diagrams for process units can be designed by means of knowledge‐based systems. The input information which has to be supplied by the process engineer comprises e.g. physico‐chemical properties, process conditions and start‐up and shut‐down procedures. The results are PI diagrams as well as the documentation of the design criteria and operating instructions if manual operations on site are necessary. The potential of knowledge‐based computer‐aided design of PI diagrams is demonstrated in the case of pumps in chemical plant.
DIN‐Norm‐orientierte Standard‐Spezifikationen für Rührwerke
Authors: Simon Eberhard 
Published: December 2004

AbstractDIN Standard‐Oriented Specifications for Stirring Systems. Stirring as a unit operation is characterised by universal application possibilities for material and energy transmission in process industries. DIN standards provide an overview of the wide variety of equipment in technical use and define the conditions for low‐cost, exchangeable standard stirring systems. In many cases important process parameters are fixed only for a limited time. Possible operation time should be long, therefore performance reserves are justified; they will be useful for later tasks as well as for improving safety of existing processes. Engineering of such stirring systems requires definition of standard stirring tasks. This article deals with economic aspects, defines standard stirring tasks as well as design conditions and shows the principal engineering data of standard stirring systems for stainless steel vessels up to 20 m3 by means of pictures, tables and nomograms. In conclusion, adequate processing of construction materials as well as surface finishing and practical work with standard specifications for stirring systems are discussed.
Nichtbiologische Reinigung organisch verschmutzten Wassers
Authors: Mersmann Alfons , Kutzer Stephan , Kajszika Holger , Wintrich Hans 
Published: December 2004

AbstractNon‐Biological Removal of Organic Pollutants from Water. Contaminants present in waste water, seepage water and ground water include salts, heavy metals and organic compounds of low biodegradability. This paper considers the wide range of physico‐chemical processes available for separation of such compounds from water and points out their optimal and economic range of application. Main subjects are desorption processes (air/steam stripping), adsorption processes (activated carbon, polymeric resins) and membrane separation processes. Alternative water treatment technologies (evaporation, distillation, liquid‐liquid‐extraction, oxidation, flocculation and precipitation) and combined processes are presented and discussed.
Anwendung der Molchtechnik in der chemischen Industrie
Authors: Mühlthaler Wolfgang 
Published: December 2004

AbstractUse of Pigging in the Chemical Industry. Use of piggable pipework systems can lead to dramatic savings in investment costs and to high efficiency of the installed pipework. Emptying and washing operations are no longer necessary. Moreover, losses of valuable raw materials and finished products are avoided, the contamination waste water needing treatment, and hence the environmental burden, is reduced. A small number of pipes suffices for transport of many different substances with a high degree of separation. Pipework systems with pigging equipment in regular operation remain free from deposits. Complete automation eliminates the possibility of operating errors. However, it should not be forgotten that such a system also generates operating and maintenance costs which vary according to product. A decision to introduce a pigging system must ultimately depend upon the economics and availability of the plant.
Olechemie – Chemieprodukte auf der Basis nachwachsender Rohstoffe
Authors: Breucker Christoph , Jordan Volkmar , Nitsche Michael , Gutsche Bernhard 
Published: December 2004

AbstractOleochemistry – Chemical Products Based On Renewable Raw Materials. Because of the increasing demand of consumers and industry for “green” products, the importance of the oleochemistry will grow in the future. This paper shows that the modern oleochemistry has developed from „soapboiling”︁ to a part of the chemical industry which requires all elements of chemical engineering. A wide and pretentious area of activities concerning unit operations and reaction technology is offered to the chemical engineer. The thermal sensitivity of raw materials and products results in high demands in the production process.
Thermodynamische Modelle zur Analyse der Verfahren für die thermische Entsorgung von Müll
Authors: Barin Ihsan , Igelbüscher Andreas , Zenz (Fh) Franz‐Rudolf 
Published: December 2004

AbstractEvaluation of processes for thermal disposal of residual waste according to technical, economic, and ecological criteria has long been a topic of discussion in specialist circles. A basis for such evaluation is provided by material and energy balances determined by operational measurements and supplementary calculation. Thermodynamic process simulation can be regarded as a powerful engineering tool in preparing such balances; its use enhances the objectivity in analysis of various procedures and their comparison with the aid of material, energy, and entropy balances. However, this requires practically relevant calculation models. In this connection, the software used must be able to cope with the states of materials as completely as possible with due attention to technical boundary conditions. Practical knowledge is of decisive importance for the quality of process simulation. In the present work this was permitted by the collaboration of industrial companies arranged by the State Environmental Office of North Rhine‐Westphalia.