bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ziele und Methoden der elektrochemischen Verfahrens‐ und Reaktionstechnik
Authors: Wendt Hartmut 
Published: December 2004

AbstractObjectives and methods of electrochemical process and reaction engineering. Electrolysis processes are distinguished from „normal”︁ chemical processes in several respects: (1) The electrical energy consumed is expensive and assumed the role of an expensive raw material. (2) Mass transfer in electrolytes is sluggish and limits space time yield to relative low values. (3) The rate of reaction is dictated by the applied electrode potential and this determines the cell voltage and energy efficiency of electrolysis processes. Effective electrocatalysts diminish energy consumption per unit mass of product. (4) The relatively poor electrical conductivity of electrolytes leads to construction of special closely spaced cells with narrow cell gaps. It is important to select the operation conditions of, e. g. organo‐electrosyntheses to minimise the efforts involved in isolation and purification of the product.
Einsatz von programmierbaren Taschenrechnern für verfahrenstechnische Berechnungen
Authors: Hüning Werner , Brunberg Raimund 
Published: December 2004

AbstractUsing of programmable pocket‐calculators for process engineering calculations. Part of a chemical engineer's daily work are repeated calculations to illustrate special relations. Suitable for this purpose are programmable pocket computers, which allow easy and quick programming by the user. This contribution gives brief instructions for creation of short and more complex programs in addition to those found in the user's manual. Independently of calculator type and nature of the problem, the single steps required to get a complete program are described. Using a special example from chemical engineering, the optimal pathway from the algorithm to the program listing is shown for two calculator types.
Technologien zur Sanierung von Bodenkontaminationen und Altlasten
Authors: Deckwer Wolf‐Dieter , Weppen Peter 
Published: December 2004

AbstractTechnologies for the clean‐up of soil contamination and older burdens. Older burdens as a consequence of fast industrialization and soil contamination by leakage and accidents require fast clean‐up. Sealing measures and storage on disposal sites postpone solution of the problem to some day in the future. Thermal treatment and washing entail extensive earth‐moving operations. They have a high energy requirement and are expensive. Microbiological processes presently under development are expected to yield less expensive solutions. The degradation properties of soil microflora or specially cultured microorganisms are exploited for this purpose. Treatment of lower‐lying contamination requires an adequate oxygen supply at the site of action.
Verfahren zur Mikrofiltration von Prozeßlösungen und ihre Anwendungen
Authors: Ripperger Siegfried 
Published: December 2004

AbstractApproaches to microfiltration of process solutions and its application. Particles and microorganisms in the site range of 0.02 to 10 μm are reliably removed by microfiltration processes. Microporous polymer membranes are suitable as filter medium. The particles are then separated mainly on the exterior surface (surface filtration). This leads to formation of a covering layer on the membrane and a relatively high hydraulic resistance. Dynamic filtration processes counteract covering layer formation. The most widely developed technique is crossflow microfiltration, in which the membrane is subject to continuous flow of the suspension. The development of large membrane units fulfils requirements for large‐scale industrial application of crossflow microfiltration.
CAE in der Prozeßleittechnik
Authors: Geibig Karl‐Friedrich 
Published: December 2004

AbstractCAE in process control engineering. The design and operation of chemical engineering plant involves collaboration of various specialist departments over a long period in an iterative sequence of steps. Any change in data in any of the necessary iterative steps can generate expensive errors. The aim of computer application and computerized development is thus basically to improve the integration of the various applications. Technical data processing, especially the use of CAD/CAE systems, therefore provides a framework for a whole group of measures intended to provide tools for mediumterm automatic handling of data and re‐use of partial solutions in memory.
Abscheidung von Feinstaub aus Gasen
Authors: Löffler Friedrich 
Published: December 2004

AbstractExtraction of fine dust from gases. The main focus of interest and of problems in the area of particle extraction from gases has been shifting more and more towards fine dusts, i.e. dusts with considerable fractions below 10 ßm, sometimes far below 1 ßm. Solution of extraction problems in this range either requires new processes, of which there are not many, or, on use of conventional extractors, calls for modified engineering concepts and modes of operation. This survey first describes some typical sources of fine dusts and then considers various procedures for their extraction.
Spezielle Korrosionsschutz‐Maßnahmen im Chemie‐Apparatebau
Authors: Kuron Dieter , Gräfen Hubert 
Published: December 2004

AbstractSpecial corrosion protection measures in fabrication of chemical equipment. An essential pre‐condition for uninterrupted and safe operation of equipment is a proper selection of materials with regard to service conditions, design, and fabrication. In case of difficulties with the application of unprotected metallic materials suitable additional measures must be applied to ensure proper performance of the equipment. Basically, there are four types of measures. The material can be improved by modification of the composition or fabrication (e. g. powder metallurgical, remelt techniques, accurate welding); the material can be protected by the application of a duplex‐system (lining, cladding, plating); the electrochemical performance of the metal can be influenced by superimposed currents (cathodic/ anodic protection); and last but not least a change in service conditions can meet the requirements for materials performance. To ensure satisfactory performance of protective measures, supervision of application, installation, and in‐service behaviour is a must.
Simulation in der Prozeßleittechnik
Authors: Kreitner Hermann , Schuler Hans 
Published: December 2004

AbstractSimulation in process control. Distributed control systems provide their users with many potential benefits which are exhaustively used only in a small number of applications. Distributed control systems supply process data in real time in a digital format. When processing these data together with process models, the advantages of distributed control systems can be considerably extended. Process models are understood as mathematical systems containing a‐priori knowledge about processes in a numerical or logical form. In the context of distributed control systems, some new and exciting applications of modelling and simulation techniques become accessible. Basic concepts of these specific techniques are described in this contribution. A collection of potential and realized applications show that these methods allow for a more detailed observation and for advanced process control strategies.
Korrosionserscheinungen in strömenden Medien am Beispiel von Chemiepumpen
Authors: Tischner Hermann 
Published: December 2004

AbstractCorrosion phenomena in flowing media, illustrated for chemical pumps. It is shown how centrifugal pumps in chemical plant are exposed to a complex superposition of (static and dynamic) mechanical and thermal stresses, of corrosion, erosion/abrasion and cavitation. Then examples of pump parts that have been operated under service conditions are shown to demonstrate appearance and origin of flow‐induced, erosion‐ and cavitation‐corrosion. Materials concepts are discussed that are able to avoid or reduce these phenomena. Several pump‐like test methods are introduced that permit selection of pump materials in accordance with the practical service conditions, where hydraulic, design, and materials criteria have to be optimized to guarantee long pump lives.
Apparate aus Sonderwerkstoffen
Authors: Donat Helmut 
Published: December 2004

AbstractEquipment made of special materials. Errors in the planning phase of capital expenditure and major repairs often lead to particularly high costs in remedying them. The investigations that were necessary to ensure reliable manufacture are described with reference to a heat exchanger made of zirconium. In addition to design details, the testing of the explosiveclad tube sheets and the welding of the heat exchanger tubes are explained at length. In the repair sector a report is given on damage to an evaporating vessel made of nickel‐clad sheet. Particular attention is paid to the build‐up of tension in the cladding in relation to the support material. A second example of damage is used to show the influence of design details on the damage mechanism. In this case Monel 400 piping is involved.
Wärmeübertragung zwischen einer Wand und dispersen Gas/Feststoff‐Systemen
Authors: Tsotsas Evangelos , Martin Holger 
Published: December 2004

AbstractHeat transfer from a rigid wall to gas‐solid particulate systems. Considerable progress made in the last twenty years now permits a better understanding of heat transfer between a rigid wall and gas/solid particulate systems. The following paper reviews this progress. The heat transfer from a rigid wall to fixed, agitated, and fluidized beds as well as to fixed beds with fluid flow is discussed, and an example of indirect cooling of high‐capacity computers is given. In modelling, the concept of a contact and a penetration resistance in series is applied. The physical significance and the calculation of these resistances are discussed.
Vergleich von Laser‐ mit Elektronenstrahlschweißen
Authors: Anderl Peter 
Published: December 2004

AbstractComparison of laser with electron beam welding. International industry requires products of the highest technical standards thus requiring application of the technologically most efficient and most economical processes. For this reason, the electron beam and laser welding processes are becoming more and more important. To provide a workpiece‐relevant basis for deciding which technique should be used the following aspects will be investigated: generation of the beam, beam guidance systems, welding processes, application and power ranges, process controls, and equipment for industrial use. Finally a tabulated comparison should facilitate a detailed distinction between the two techniques.
Stoffumwandlung und Stoffaustausch bei Flüssig/Flüssig‐Systemen
Authors: Bart Hans‐Jörg , Marr Rolf , Bauer Andreas 
Published: December 2004

AbstractChemical reaction and mass transfer in liquid/liquid systems. In systems with mass transfer and chemical reaction, one has to consider the solubility of the solute in the receiving phase. Modelling of the phenomena will be according to gas/liquid systems for soluble solutes and according to gas/solid systems for insoluble solutes. Criterion for a further lay‐out of a contact apparatus is either the Hatta‐ or the second Damköhler number. This will be demonstrated for the extraction of copper as an example for a countercurrent cascade of mixers and countercurrent columns.
Sicherheitstechnische Kenngrößen und ihre Bedeutung für die Planung und den Betrieb von Chemieanlagen
Authors: Berthold Werner , Löffler Ulrich 
Published: December 2004

AbstractSafety characteristics and their significance for planning and operating chemical plant. A knowledge of safety characteristics is a must for a safe operation of chemical processes. Disasters in chemical plant often occur due to a lack of knowledge of dangerous properties of the handled substances. Unexpected explosions or runaway reactions have been the result. Safety characteristics describe the reaction behaviour of substances as well as the fire and explosion hazards, provided that they are accurately determined and interpreted. This paper will sensitize research scientists, project engineers, and producers of chemicals to ensure that safety characteristics are correctly evaluated and applied in practice.
Rückgewinnung von Ammoniak aus Industrieabwasser
Authors: Marr Rolf , Končar Michael 
Published: December 2004

AbstractRecovery of ammonia from industrial waste water. On the basis of new ecological findings, waste waters containing residual amounts of ammonia or ammonium ion formerly regarded as safe must now be classified as a serious potential hazard for the environment. Since new limits for ammonia/ammonium in waste waters are to be expected in the near future, considerable research and development work is currently being invested in the separation and recovery of ammonia. The present article considers the ecological problems relating to ammonium and states the sources of such effluents. Moreover, possible separation processes and recovery methods are reviewed and the pros and cons of the individual processes compared.
Polymerwerkstoffe im Chemie‐Apparatebau
Authors: Busse Horst , Schindler Helmut 
Published: December 2004

AbstractPolymer materials in chemical plant equipment. The range and technical sophistication of organic materials today provide the chemical industry in particular with economical and highly dependable materials able to fulfill functions which previously required the use of expensive metals. Polymer materials suitable for use in chemical plant equipment can basically be subdivided into thermoplastics, elastomers, thermosets, and composites. They are used in the form of solid structures or as protective coatings. Recent years have seen a marked increase in the importance of self‐vulcanizing rubber linings for on‐site application (e.g. in sewage treatment and flue gas desulphurization plants), composite structures based on fluorinated polymers for acid recovery and electrically conducting polymers for the transportation of corrosive, combustible gases and vapours.
Mikroporöse Filtermedien für die Kuchenfiltration
Authors: Bott Reinhard 
Published: December 2004

AbstractMicroporous filters media for cake filtration.Improved knowledge about filtration conditions, capillary phenomena in filter cakes and in filter media, as well as the properties of membranes permit the use of microporous membranes in cake‐forming filtration. This allows removal of moisture without passage of gas and yields a particle‐free filtrate. Apart from metallic and ceramic membranes, polymeric membranes prove highly suitable as microporous filter media since they permit utilization of the entire range of filter equipment. The present article considers first the fundamentals of cake‐forming filtration, then surveys the various membrane systems, and finally discusses process‐engineering aspects of filtration with microporous filter media.
Zerstäuben von Flüssigkeiten
Authors: Walzel Peter 
Published: December 2004

AbstractAtomizing of liquids. Atomizing of liquids, i.e. the formation of droplets in a continuous gas phase or in vacuum, is accomplished in most cases by atomizer nozzles. Single substance pressure nozzles and pneumatic atomizers or air blast atomizers are alternative devices for that purpose. The physical facts of the partition process of the liquid and two phase flow conditions are now better known thanks to recent investigations. This permits estimation of the effect of the most important parameters on the median drop size by equations of physically based dimensionless groups. The different methods referred to in the literature for determining drop sizes lead to different results and therefore still represent a problem. Nevertheless, an attempt is made to give simplified and physically sound equations for estimating droplet size for the most important kinds of atomizers. They provide the user with an overview of the principal influencing factors and should facilitate choice of a suitable atomizer. Besides the frequently applied methods for drop and spray formation, other processes are also described which are used in special cases.
EDV‐gestützte wissensbasierte Prozeßsynthese
Authors: Simmrock Karl Hans , Fried Birgit , Fried Andreas 
Published: December 2004

AbstractComputer‐aided knowledge‐based process synthesis. Process synthesis as a branch of process development serves to structure chemical processes. Since it is largely influenced by trial‐and‐error knowledge, knowledge‐based programming resulting from AI research (Prolog, LISP, Shells) opens up new possibilities compared to conventional procedural systems (Fortran, PL/1). The immense area of knowledge of process synthesis soon requires subdivisions into smaller knowledge domains for which expert systems first arise as island solutions, which subsequently combine as cooperating distributed expert systems. A possible procedure is illustrated for the knowledge based process synthesis program PROSYN/REXPERT PLUS.
Abtrennung und Rückgewinnung von Stoffen aus Abluft‐ und Abgasströmen
Authors: Müller Günter , Ulrich Michael 
Published: December 2004

AbstractRemoval and recycling of components from air and gas waste streams. Removal and recycling of components from air and gas waste streams are becoming more important as purified gas streams must fulfil the requirements of national emission regulations (TA Luft in Germany). Processes for the removal of organic and inorganic components from gas streams are condensation, absorption, adsorption, and permeation. Physical principles, uses and limits of these processes, and appropriate apparatus are discussed.
Projektmanagement im Anlagenbau
Authors: Mosberger Erich 
Published: December 2004

AbstractProject management in plant construction. Project management is a management concept increasingly employed in project execution both by industry and administration. There are variants to this management concept allowing it to be readily adapted to individual applications. Engineering companies are typically confronted with multi‐project management tasks, i. e. they handle concurrently a great variety of projects differing in size, complexity, and duration. For each project, specialists from various disciplines of the company have to be coordinated across department lines and their performance channelled under project management leadership. Matrix project management lends itself particularly well to this task, the personality of the project manager playing a central role.
Abtrennung und Rückgewinnung von Stoffen durch Adsorption und Ionenaustausch
Authors: Cornel Peter 
Published: December 2004

AbstractSeparation and recovery of materials by adsorption and ion exchange. Activated carbons are capable of removing dissolved organics from waste water. They can be used in granular or powdered form, instead of, before, during, or after biological treatment or in water recirculation systems. Usually the adsorbed organics cannot be recovered. Granular activated carbon can be regenerated by thermal reactivation. The use of other adsorbents such as adsorption resins is limited to special cases. Ionic compounds can be removed by ion exchange media. The most common of these are synthetic ion exchange resins. They are used for the treatment of rinse water and pickling effluent. Gold, silver, copper, mercury, chromate, etc. can often be recovered. The degree of separation achieved and the amount of regenerant required – which should be minimized for ecological and economic reasons – depend on process parameters and design.
Beiträge der Prozeßleittechnik zur Qualitätssicherung in der chemischen Produktion
Authors: Eckelmann Wolfgang , Schuler Hans 
Published: December 2004

AbstractContributions of Process Control to Quality Assurance in the Chemical Industry. Through their functions of measurement, i.e. the acquisition of quantities relating to the process and the product, and adjustment, i.e. the modification of control values, process control engineering and process automation represent the basis of all operative control of quality. The functions of control, regulation, and operator support are likewise instruments ensuring the maintenance of quality‐relevant process and product specifications. Utilisation of the considerable potential of these tried and tested control methods is logical in the case of chemical processes and should receive more attention in quality management.
Energetische Nutzung von Biomasse – Verfahren zur Herstellung von Synthesegas, Wasserstoff, Methanol und flüssigen Brennstoffen
Authors: Plzak Vojtěch , Wendt Hartmut 
Published: December 2004

AbstractDie Verfahren zur Aufbesserung der Brennstoffeigenschaften von Biomasse orientieren sich weitgehend an der Vergasung oder Verflüssigung von Braunkohle. Die hydrierende Umsetzung der in der Biomasse vorliegenden Biopolymere (Cellulosen, Lignin und Lignocellulosen) erfordern vor dem hydrierenden Angriff den chemischen Abbau der komplexen Biopolymer‐Matrix. Man unterscheidet pyrolytische Verfahren (350 bis 500°C, drucklos) von den unter Druck durchgeführten hydrolytischen, solvolytischen und extraktiven Verfahren. Die relativ hohen Investitionskosten der Iysierenden Verfahren erfordern wegen der “Economy of scale” eine Mindestanlagengröße von mehreren hundert MW. Die Biomassevergasung und die darauf aufbauende Wasserstoff und Methanol‐Erzeugung aus Biomasse sind vom Investitionsaufwand her gesehen auch für kleinere Anlagen geeignet. In nächster Zukunft dürfte sich die energetische Biomassenutzung allerdings auf die direkte Verbrennung in Biomasse‐Heizkraftwerken bzw. die Vergasung und Verstromung des Gases in Brennstoffzellen beschränken.
Genehmigungsverfahren für Chemieanlagen im europäischen Vergleich
Authors: Stahl Harald , Betz Monika 
Published: December 2004

AbstractComparison of Licensing Procedures for Chemical Plant in Europe. In many European countries, licensing procedures for chemical plants are at present less laborious – much less, in some cases – than in Germany. In the countries of Southern Europe, in particular, the building license is granted separately from the operating license, enabling building work to begin at an early stage. On the one hand, processing periods and official management are able to facilitate and expedite the proceedings; on the other hand, increasingly complex approval procedures, such as the obtaining of a license under the German Federal Pollution Control Act, with an additional environmental impact assessment compatibility, result in further serious delays. The proposed EC Directive on the harmonization of licensing procedures will admittedly bring equality in terms of expense, procedure and duration, but Germany is likely to continue to play a pioneering role in plant‐related environmental protection, and hence also in the implementation of the licensing procedure, for a considerable period to come.
Zertifizieren von Qualitätssicherungs‐systemen
Authors: Jahn Hans , Pärsch Joachim G. 
Published: December 2004

AbstractCertification of Quality Assurance Systems. Assurance of quality, working in a systematic and documented manner with the aim of contributing to constant improvement of the quality levels of a company, is now standard practice. A visible sign of quality competence is a quality assurance system certificate that is issued by a neutral certification body after assessment of the effectiveness of existing quality assurance systems. The German Society for the Certification of Quality Assurance Systems (DQS), a neutral, not‐for‐profit institution, performs such assessment in Germany on the basis of DIN ISO standards 9001, 9002, or 9003, and issues certification of quality assurance systems.