Herbert Pfeifer

• Univ.-Prof. Dr.-Ing.
• RWTH Aachen University

Impingement jets are used in many applications for high convective heat transfer. In order to optimise specialised nozzle systems, a comprehensive understanding of the gas flow is essential. The aim of this work is to investigate high-convective flows at Re = 10,000 to Re = 50,000 for a single slot nozzle (slot width W = 5 mm) and a slot nozzle arr...

In industrial plants, metal strips are quenched using convective heat transfer. This involves accelerating gas through a nozzle system onto the material to be quenched, resulting in a fast and uniform cooling process. The efficiency of the heat transfer is determined by the specific nozzle system. The presented work is focussed on the analysis of t...

A feasibility study was made within IGF research project „Inline-Sauerstoff“ to declare, if a process-integrated O2 production is able to save OPEX, CO2 emissions and to increase competitiveness of iron foundries. A membrane process was in focus, enabling a scalable and efficient O2 production on-site. The results were presented and discussed.

In convection-dominated thermoprocessing plants, the current state of the art is to use centrifugal and axial fans in conjunction with flow straighteners to ensure a homogeneous inflow of the fluid and thus a homogeneous temperature distribution. However, flow straighteners lead to an additional pressure loss in the system that must be overcome. Ta...

The use of structured tubes in tube bundle recuperators is intended to improve the energy efficiency of gas-fired industrial furnace systems with central air preheating. Currently, smooth tubes as well as smooth tubes with internal twisted tape are commonly utilised. The increased surface area of structured tubes leads to an increased heat transfer...

2) Lehrstuhl für Thermodynamik und Verbrennung, Otto-von-Guericke-Universität Magdeburg Im Rahmen der Produktion von metallischen Werkstoffen in kontinuierlichen Bandanlagen ist die Abkühlung ein zentraler Prozessschritt der Wärmebehandlung, da die resultierenden Werkstoffeigenschaften des finalen Produkts durch die Abkühlung entscheidend beeinflus...

The interest in ultra-pure metals is steadily growing due to the increasing demand for these materials in modern technology. To be able to meet the increasing demand in the future, it is necessary to implement more efficient and productive processes. As a fractional crystallization method in this application area, the cooled finger method exhibits...

The reduction of CO2 emissions in hard-to-abate industries is described in several proposals on the European and National levels. In order to meet the defined goals, the utilization of sustainable, non-fossil fuels for process heat generation in industrial furnaces needs to be intensified. The focus mainly lies on hydrogen (H2) and its derivates. F...

Tube bundle recuperators are generally designed to operate with smooth tubes. Structured tubes can be used to increase the efficiency of recuperators. Compared to smooth tubes, the surface for heat transfer is increased and thus heat transfer is enhanced. This effect is accompanied by an increased pressure loss, which must be kept as low as possibl...

Gas impingement jets are widely applied in industrial cooling processes. In continuous heat treatment lines of steel, aluminium and copper strips, impingement jet nozzle systems are utilised to achieve rapid cooling or heating. The heat transfer depends on the flow but also on the geometric parameters such as nozzle to strip distance and the nozzle...

In 2020 approximately 1.5 Mt of dusts and sludges were produced in German steel plants along the integrated steel routes. In addition, there are other significant quantities of by-products and residues from other metallurgical areas such as foundries or manufacturing processes for non-ferrous metals. These secondary materials still contain valuable...

In 2020 approximately 1.5 million tons of dusts and sludges were produced in German steel plants along the integrated steel route via blast furnace and LD converter. This residues from steel making still contain considerable amounts of Fe-oxides as wustite, magnetite and hematite. Thereby, these residues are undergoing intense internal recycling fo...

Impingement jets are widely applied in industrial cooling processes. In continuous heat treatment lines of steel, aluminium and copper strips, impingement jets are used to achieve rapid cooling or heating. The heat transfer depends on the flow but also on the geometric parameters such as nozzle to strip distance and the nozzle shape. The key challe...

Calculating the radiation exchange between arbitrary surfaces using view factors is a common practice in the fields of industrial furnaces, climate modelling, solar power, thermal building design and so on. Here, a new model was developed to calculate the view factors of arbitrary two-dimensional geometries. This model is based on Hottel’s crossed...

Electroslag remelting (ESR) is a well‐known process widely used in the production chain of high‐quality alloys. Herein, numerical investigations of the implementation of a rotating‐electrode (low rotation speed) modification to the flow behavior inside the slag area of a lab‐sized ESR process are shown. Therefore, a coupled simulation approach betw...

Numerical simulation is a vital tool for the continuous improvement of all steelmaking processes. In previous works, the authors have dedicated different approaches to optimize modeling of fluid flow in the ladle. This includes a sensitivity analysis of validation techniques, assembling of a validation database, and a model optimization on the wate...

Self-recuperative burners are a common solution for efficient combustion systems in industrial furnaces. Due to the geometric complexity of the recuperators, a detailed CFD simulation is computationally expensive and not feasible for simulation models of burner-integrated systems such as radiant tubes. Especially in the FSI studies of radiant tubes...

Energieintensive Branchen wie die Stahl, Glas, Keramik oder die Nicht-Eisenmetallurgie, werden durch die Energiewende vor die Herausforderung gestellt, ihre vorhandenen Thermoprozesse und Anlagentechnik auf CO2-arme bzw. CO2-freie Technologien umzustellen. Der Anlagenpark in Deutschland ist dabei durch eine Vielzahl unterschiedlicher Thermoprozessa...

The electro-slag remelting (ESR) is a well-known process, which is widely used in the production chain of high-quality alloys. These alloys are used for many different applications ranging from tool steels to superalloys used in aero-or spacecraft applications. The process design is mainly unaltered since several decades. There only have been impro...

Energieintensive Branchen wie die Stahl, Glas, Keramik oder auch die Nicht-Eisenmetallindustrie, bei denen neben energiebedingten Treibhausgasemissionen auch besonders schwer vermeidbare, technisch-physikalisch bedingte Prozessemissionen eine Rolle spielen, werden durch die Energiewende und den damit verbundenen zunehmenden Einsatz erneuerbarer Ene...

Die Nutzung von fossilen Brennstoffen stellt im Industriesektor die Hauptquelle direkter Treibhausgasemissionen dar. Besonders die Erzeugung von Prozesswärme ist hierbei von Relevanz und machte im Jahr 2015 zwei Drittel des gesamten Endenergieverbrauchs des Industriesektors aus. Die Bereitstellung der Energie für die Industrie erfolgte im gleichen...

The electric arc furnace (EAF) represents the most important process route for recycling of steel and the second most productive steelmaking process overall. Considering the large production quantities, the EAF process is subject to continuous optimization, and even small improvements can lead to a significant reduction in resource consumption and...

Improving the overall energy efficiency of processes is necessary to reduce costs, lower the specific energy consumption and thereby reduce the direct or indirect emission of gases that contribute to climate change. In many metallurgical processes, a large amount of energy is lost with the off-gas. In metallurgical recycling processes, off-gas ofte...

Oberflächenkontakte zwischen Festkörpern treten in vielen Bereichen der Thermoprozess- und Umformtechnik auf. Diese Oberflächenkontakte verursachen einen zusätzlichen Wärmewiderstand. Eine genauere Kenntnis dieser Widerstände kann dazu beitragen, die Prozessmodellierung oder die Auslegung von Anlagen zu verbessern. Im Rahmen der Industriellen Gemei...

The reliable operation of a radiant tube furnace is essential to run a profitable continuous galvanizing line (CGL). Short radiant tube lifetime resulting in premature tube failures may result in loss of production capacity arising from reduced heat input or, worse, unplanned plant shutdowns. As a galvanizing line furnace equipped with around 200 r...

Measurements at high-temperature facilities such as galvanizing lines are often possible only to a limited extent. Moreover, many of the processes involved are too complex to apply existing numerical methods such as CFD to provide the desired information. Therefore, an empirical method was developed to estimate process data which is not measured. T...

The steel industry in Germany is a very important part of the economy. Sales in the industry amounted to 39.1 billion euros in 2019, which makes it the third largest industry in terms of sales (German Steel Federation – Fakten zur Stahlindustrie 2020). In the con-text of this work, the processing of steel slabs and billets produced in continuous ca...

Gas bubbles are of major importance in most metallurgical processes. They promote chemical reactions, homogenize the melt, or float inclusions. Thus, their dynamics are of crucial interest for the optimization of metallurgical processes. In this work, the state of knowledge of bubble dynamics at the bubble scale in liquid metals is reviewed. Measur...

Warmmassivumgeformte Komponenten werden zu Beginn des Prozesses homogen erwärmt, um eine definierte Fließspannung einzustellen und damit das gewünschte Umformverhalten zu erreichen. Ein aktuelles Forschungsprojekt untersucht die gezielte inhomogene Erwärmung von Bauteilen und die damit einhergehende räumlich verteilte Einstellung der Umformeigensch...

Energieintensive Branchen wie die Stahl, Glas, Keramik oder die Nicht-Eisenmetallurgie, bei denen neben energiebedingten Treibhausgasemissionen auch besonders schwer vermeidbare, technisch-physikalisch bedingte Prozessemissionen eine Rolle spielen, werden durch die Energiewende und den damit verbundenen zunehmenden Einsatz erneuerbarer Energien vor...

To account for increasing economic and ecological pressure, the steel industry is obligated to continuously optimize all processes. An important optimization approach is numerical modeling although its potential is limited by the accuracy of the mathematical models. In a previous work, a validation database was created and a validation score was de...

In numerical computation of ladle metallurgy, multiphase models are essential. Still, these models are afflicted with great uncertainty, making a validation with experimental data mandatory. Validation experiments fundamentally differ from physical modelling experiments because emphasis is on a complete documentation of all boundary conditions and...

It often takes only 60 days from the sale, consumption, return to recycling systems, through remelting with subsequent can production and filling, to the resale of a beverage can. Conventional coatings on cans reduce the melting yield and disrupt a sustainable circular economy. However, the use of novel and already certified polyolefin dispersion c...

Gas fired industrial furnaces with protective gas atmospheres use radiant tubes, muffles, or similar devices to separate the furnace atmospheres from combustion off gases. Heat is transferred to the furnace mainly by radiation from the tubes surfaces. Some commercial attempts were made to increase the surface areas of radiant tubes by adding bulged...

In der Thermoprozesstechnik treten Oberflächenkontakte zwischen Festkörpern an vielen Stellen auf und führen zu zusätzlichen Wärmewiderständen. Die Kenntnis dieser Widerstände kann relevant für die Prozessmodellierung oder die Auslegung von Anlagen sein. Im Rahmen der Industriellen Gemeinschaftsforschung wurde ein Versuchsstand zur Bestimmung von K...

Detailed knowledge about gas-liquid multiphase flows is important to optimize industrial systems. Imaging with image processing is the most commonly used measurement technique. However, the workflow and parameters strongly depend on the experimental conditions and no generally applicable process has been developed yet. Here, a workflow based on con...

Für Umformprozesse in der Massivumformung werden Bauteile homogen erwärmt, um die temperaturabhängigen Fließspannungen einzustellen und damit das gewünschte Umformverhalten zu erreichen. Eine gezielte inhomogene Erwärmung des Bauteils und der damit einhergehenden räumlich verteilten Einstellung der Umformeigenschaften wird im Rahmen eines aktuellen...

Featured Application Towards the development of a full-fledged model for the prediction of radiant tube lifetime in strip annealing furnaces, to serve its end-user through integration into the process-and control-strategies. Abstract The effects of surrounding radiation—emanating from radiation exchange with neighboring partners in indirect-fired...

In the field of industrial furnace construction, the radiant tubes used for heating are critical components. The radiant tubes, which contain a gas burner, are used for separating the oxidizing gas from the furnace atmosphere. An industrial furnace used e.g. for heat treatment of steel strip consists of several hundreds of radiant tubes. Mechanical...

The influence of surrounding (or proximal) radiation on radiant tubes inside a continuous hot-dip galvanizing line was investigated. The furnace chamber, the strip and the neighbouring tubes were considered as the surroundings. A coupled heat transfer model was developed and subsequently validated against experimental measurements. This model was u...

Getränkedosen sind ein fest etablierter Bestandteil des Portfolios industrieller Verpackungen, obwohl sie wegen potentieller Gesundheitsrisiken immer wieder Gegenstand von Diskussionen sind. Diese Vorwürfe gelten im Wesentlichen der Chemikalie Bisphenol-A (BPA), die in Innenbeschichtungen auf Epoxidbasis und damit effektiv in nahezu jeder Dose in D...

A long service life of radiant tubes is essential for the profitable operation of galvanizing lines. A failure of the radiant tube reduces the heat input to the furnace and therefore the productivity. In the worst case, furnace downtime is necessary. Factors influencing tube life can be classified into the three main topics: Design and constructio...

Nowadays numeric methods, such as finite element method, are utilised to optimise production procedures of high-end materials and thereby increase existing production limits. Metal forming is an example for these procedures because it is an application where processes are continuously optimised. The knowledge of accurate boundary values is of high...

Nowadays numeric methods, such as finite element method, are utilised to optimise production procedures of high-end materials and thereby increase existing production limits. Metal forming is an example for these procedures because it is an application where processes are continuously optimised. The knowledge of accurate boundary values is of high...

Zur Auslegung von Bauteilen unter wechselnden Beanspruchungen werden häufig Lebensdaueranteilregeln verwendet, um eine Aussage über die erwartete Verformung zu treffen. Im Falle von Ofenkomponenten hat sich gezeigt, dass die Kriechverformung unter wechselnder Temperaturbeanspruchung bei niedrigen, konstanten mechanischen Lasten mit der Lebensdauera...

Hohe thermische Belastungen und betriebsbedingte Temperaturwechsel stellen eine Herausforderung für die Ausle-gung metallischer Bauteile in Industrieöfen, wie Strahlheizrohren, Muffeln oder Ofenrollen, dar. Bei der Bestimmung der Lebensdauer dieser Bauteile spielen Kriechen und Korrosion vor allem ab Temperaturen von 900 °C eine übergeordnete Rolle...

The arc in an electric arc furnace (EAF) is the main power source for the heat transfer and convection taking place in the slag and freeboard gasses. An improved understanding of the heat transfer and flow inside furnaces would support furnace design, operation, control, and automation. Especially in the context of integrated CFD studies of furnace...

Process model development for pyrolysis of waste printed circuit boards in microwave-heated lab-scale rotary kiln Henning Bruns, Moritz Eickhoff, Herbert Pfeifer Department for Industrial Furnaces and Heat Engineering, RWTH Aachen University, Germany Abstract Keywords: printed circuit board recycling, rotary kiln modelling, microwave heating, pyr...

Sulphur is one of the main impurities in steel. Hot metal desulphurisation constitutes the primary desulphurisation step in blast furnace-based ironmaking and is typically conducted in a ladle or in a torpedo car, using pneumatic injection of desulphurisation reagent with a submerged lance. The ability to predict the course, end-point and thus the...

Problems associated with top‐blowing are present in most steel plants. While it promotes high reaction rates, it can cause loss of yield, working hazards, and increased maintenance cost by spitting, skulling, or lid sticking. Although the basic physics of the splashing phenomenon have already been established, earlier studies have not addressed the...

Investigations were carried out on the effects of cyclic temperature changes on the lifetime of furnace components with a focus on radiant tubes. Experiments were performed under constant full-load and on/off firing of a 120 kW recuperator burner fitted into a 2.4633 P-type radiant tube. The maximum operating temperature was 1020 °C. The radiant tu...

The influence of surrounding (or proximal) radiation on radiant tubes inside a continuous hot-dip galvanizing line was investigated. The furnace chamber, the strip and the neighbouring tubes were considered as the surroundings. A coupled heat transfer model was developed and subsequently validated against experimental measurements. This model was u...

Die Energiewende und die „Zero Emission"-Ziele für CO2 stellen die Thermoprozesstechnik vor große Herausforderungen. Für die Anlagen, die einen Leistungsbereich von wenigen Kilowatt bis zu mehreren hundert Megawatt abdecken, sind brennstoffbeheizte (direkte CO2-Emission) sowie elektrische Verfahren (indirekte CO2-Emission) vorhanden. Vor dem Hinter...

Thermal processes in industry are often heated by combustion of hydrocarbons or other fuels. An O2 enrichment saves primary fuel and enables CO2 capture if pure O2 is used. Energy demand for on-site O2 production need much less electricity than thermal energy saved.

Flameless oxidation also known as flameless combustion or mild combustion is a stable combustion process characterized by low temperature gradients in the combustion region and low NOx-emissions despite high air preheating. The flameless oxidation is established in a capacity range of 30 to 300 kW. The presented research project focused on the use...

Leiterplattenschrott (gebrauchte Leiterplatten in Engl. „Waste Printed Circuit Boards“ – WPCBs) ist ein mechanisch untrennbarer Verbund bestehend im Wesentlichen aus Glasfasern, Harz, Kunststoffen und Metallen. Der Metallgehalt, insbesondere der von Kupfer und Edelmetallen, beträgt für ältere Leiterplatten ca. 40%. Bei jüngeren WPCBs ist der Metall...

Zur Auslegung von Bauteilen unter wechselnden Beanspruchungen werden häufig Lebensdaueranteilregeln verwendet, um eine Aussage über die erwartete Verformung zu treffen. Im Falle von Ofenkomponenten hat sich gezeigt, dass die Kriechverformung unter wechselnder Temperaturbeanspruchung bei niedrigen, konstanten mechanischen Lasten mit der Lebensdauera...

Mixing time is a common measure to evaluate the efficiency of homogenization in ladle metallurgy. In this study, a 1:3 scale water model of a 185 t industrial gas-stirred ladle with an eccentric porous plug at the bottom is used to study the impact of different injector designs on mixing at a constant flow rate of 16.7 slm (standard liter per minut...

Dynamic process models can contribute to more detailed understanding of the energy and mass transfers in complex processes like steelmaking in the electric arc furnace (EAF). In this presentation the recent development work and current state of a dynamic process model of an EAF is described. The presented work is a continuation of the work of Logar...

In ladle metallurgy, the flow of purge gas through injectors promotes an effective mixing of the melt concerning composition and energy. In this work, different types of gas injectors, positioned eccentrically at 66% of the ladle radius are investigated in terms of the bubble size distribution, the resultant flow field velocity, and turbulent kinet...

Industrial furnaces, especially in steel industry but also in non-ferrous, ceramic or chemical industry, are ofen fred with fossil fuels like natural gas, oil or coke. Considering the transition to green energy, it is necessary to enable the use of renewable energies like wind and solar energy in fossil-fueled furnaces. Resulting from this motivati...

The poster presents a research cooperation project of the Department for Industrial Furnaces and Heat Engineering at RWTH Aachen University and WS Waermeprozesstechnik GmbH. The objective is the development of innovative, regenerative radiant tubes with a low diameter for heat treatment furnaces with compact dimensions. The main benefit is the inst...

Die Energiewende erfordert zunehmend Konzepte, die den Einsatz von Strom aus erneuerbaren Energien in energieintensiven Anlagen ermöglichen. Das Ziel eines Forschungs- und Entwicklungsvorhabens der Firma Hülsenbusch Apparatebau GmbH & Co. KG und des Instituts für Industrieofenbau und Wärmetechnik der RWTH Aachen University ist die Entwicklung eines...

Leiterplattenschrott besteht aus einem Basismaterial, welches Glasfasern, Harze und Kupfer-Leiterbahnen enthält, den metallhaltigen elektrischen Bauteilen und einem Rest an Kunststoffen. Der Metallgehalt, insbesondere Kupfer und Edelmetalle, beträgt ca. 40 %. Bisher werden Leiterplatten zur Rückgewinnung von Kupfer und Edelmetallen in einen Schmelz...

Radiant tubes operate at a high thermal and mechanical load. A failure of the radiant tubes reduces the heat input to the furnace and therefore the productivity. In the worst case, furnace downtime is necessary. Besides choosing the appropriate material und a good dimensioning of the burner-radiant tube-system, different influences lower the lifeti...

The feasibility of applying char obtained from wheat straw fast pyrolysis as charge carbon in an electric arc furnace (EAF) for the production of steel was investigated. Fast pyrolysis char represents a by-product which could be made available at reasonable cost. It is characterized by higher volatile content than slow pyrolysis char. Prior to appl...

A common approach to reduce scale formation in the heat treatment process of semi-finished metal products is the use of a protective gas atmosphere, consisting of inert or reducing components. An innovative burner concept combines the processes of heating, protective gas generation, post-combustion of the off-gas and heat recovery in one unit. This...

Further developments and model enhancements of the described EAF process simulation model and the calculation model of the dedusting system are described within this paper. In particular, the EAF model is improved with a more detailed gas phase simulation, leading to more accurate offgas predictions for further calculations in the dedusting system...

A common approach to reduce scale formation in the heat treatment process of semi-finished metal products is the use of a protective gas atmosphere, consisting of inert or reducing components. An innovative burner concept combines the processes of heating, protective gas generation, post-combustion of the off-gas and heat recovery in one unit. This...

The energy transition in Germany towards power from renewable energy sources is progressing. Concepts for the utilization in energy-intensive plants are required. A research project of Hülsenbusch Apparatebau GmbH & Co. KG and RWTH Aachen University's Department for Industrial Furnaces and Heat Engineering is the development of a new, hybrid recupe...

Batch planning is one integral part of all industrial heat treatment processes. Its main goal is the maximization of the number of components in the batch considering the components specifications. During batch planning the temperature distribution in the batch needs to be taken into account at any point and therefore plays the decisive role. So fa...

Ein Großteil der Industrieöfen wird mit fossilen Brennstoffen beheizt. Die Energiewende erfordert jedoch zunehmend Konzepte, die den Einsatz von Strom aus Erneuerbaren Energien in energieintensiven Anlagen ermöglicht. Das Ziel dieses Projekts ist die Entwicklung eines neuen, hybriden Rekuperators mit integrierter, elektrischer Verbrennungsluftvorwä...

Radiant tubes operate at a high thermal and mechanical load. A failure of the radiant tubes reduces the heat input to the furnace and therefore the productivity. In the worst case furnace downtime is necessary. Besides choosing the appropriate material und a good dimensioning of the burner-radiant-tube-system, different influences lower the lifetim...

The following paper describes an approach to process modeling and simulation of the gas phase in an electric arc furnace (EAF). The work presented represents the continuation of research by Logar, Dovžan and Škrjanc on modeling the heat and mass transfer and the thermochemistry in an EAF. Due to the lack of off-gas measurements, Logar et al. modele...

The electroslag remelting (ESR) process is used for the chemical refinement of high quality steel and titan- or nickel-based alloys, in which liquid metal droplets are refined by falling through a bath of molten slag. In recent years the theory, that a rotary movement of the electrode could further enhance the chemical refinement due to smaller liq...

Industrial furnaces for reheating semi-finished metal products are often direct fired with natural gas and air. Oxidation of the metals exposed to the furnace atmosphere causes significant material losses and additional work during furnace operation and in further processing. A reheating concept, which reduces scale formation, was developed for dir...

Scale formation in reheating and heat treatment furnaces causes a significant metal loss on semi-finished metal products. The presented project is about the development of a burner that produces a low oxidizing / reducing atmosphere in the furnace with a thermal efficiency comparable to state-of-the-art recuperative burners. The concept combines di...

The modern Industrial Furnace Technology is characterized by the design of new furnaces for high strength metals and carbon fibers for the light weight construction concepts in automotive industry. The furnaces for the annealing of modern high strength metals (steel, Al), are characterized by innovative cooling sections, with high cooling rates and...

Aluminium is a key material in modern society and serves the needs because of the unique properties of the metal and its alloys. Scientific evidence and rational economic theories have repeatedly demonstrated that recycling is the most critical and efficient pathway to sustainable human development. Aluminium products like Used Beverage Cans or Con...

The meaning of numerical simulations of metallurgical reactors has increased during the last years. The simulations offer detailed information about the process and new insights into regions, which are typical difficult to examine. For the simulated remelting processes the growth direction of the dendrites is most important. The correlation between...

Beside computational intensive methods like CFD or FEM, reduced modelling approaches for technical processes may be more practical, especially in production environments. A modelling approach, which can be applicable for industrial processes to predict the heating of products, semi-finished materials or raw materials, will be shown. To derive such...

Within the scope of the project P5 of the Advanced Metals And Processes (AMAP) research cluster in Aachen a virtual remelting furnace by means of Computational Fluid Dynamics (CFD) modelling is set up to investigate the resource and energy efficiency of the aluminium recycling process in such kind of furnaces. One part of this numerical furnace mod...

The optimization of the electric arc furnace (EAF) is driven by increasing demands on sustainability and efficiency of the melting process. Therefore, alternative input materials as well as comprehensive process monitoring and control are aiming to minimize the ecological footprint of the electric steelmaking. Here, dynamic process models and simul...

Due to increasing cooling rates in cooling sections for the heat treatment of high-strength steel materials, unwanted strip oscillations can occur. The phenomenology of these vibrations and the heat transfer coefficient are investigated by two experimental set-ups. Thereby the strip is stimulated by the flow broadband and reacts in its eigenmodes....

The modelling of solidification processes in combination with fluid flow is one main application of ANSYS Fluent. The solid-ification is modelled with the enthalpy porosity technique. Therefor the fluid flow is damped like a flow through a porous media of dendrites. In case of materials with large solidification ranges, like the nickel based supera...

The electroslag remelting (ESR) process, which is used to produce large ingots of high quality, bases on controlled solidifica-tion and chemical refinement mechanisms and is essential for the production of high quality steels and alloys designed for aeronautical , reactor chemical or nuclear applications. Due to this, it is indispensable to enable...

Die Prozesse in Wärmebehandlungs- und Schmelzöfen lassen sich auf sehr unterschiedlichen Arten und Weisen modellieren und simulieren. Der passende Ansatz für die Entwicklung eines Prozessmodells hängt dabei stark vom Fokus der Untersuchung ab: soll etwa der elektrische Energieverbrauch eines Elektrolichtbogenofens auf der Basis historischer Betrieb...

Nowadays, neodymium is almost solely produced by the electrochemical reduction of Neodymium oxide in fused fluoride salts. Thereby, the fluid flow distribution within the electrolysis cell is important for the productivity and efficiency of the process. In this work, the flow field within a conventional cell with vertical electrodes is compared to...

Dynamic process models and simulations are able to contribute to more detailed understanding of energy and mass transfers during the melting process in an electric arc furnace (EAF). Especially the EAF off-gas offers development opportunities, due to its energy output of approximately 20 – 30 % of the entire energy input. The following paper presen...

One of the main reasons for metal loss of semi-finished metal products during heating in reheating and heat treatment furnaces is scale formation. In the presented project a burner is developed which produces a low oxidizing/reducing atmosphere in the furnace. The concept is realized by a recuperative burner, which generates a reducing furnace atmo...