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Sample records for arc furnaces

  1. Laboratory arc furnace features interchangeable hearths

    Science.gov (United States)

    Armstrong, J. L.; Kruger, O. L.

    1967-01-01

    Laboratory arc furnace using rapidly interchangeable hearths gains considerable versatility in casting so that buttons or special shaped castings can be produced. It features a sight glass for observation.

  2. Electric arc furnace models for flicker study

    Directory of Open Access Journals (Sweden)

    Catalina González Castaño

    2016-06-01

    Full Text Available Objective: The aim of this paper is to evaluate voltage fluctuations or flicker of two electric arc furnace models through comparison with real data.Method: The first proposed model is founded on the energy conservation principle, which generates a non-linear differential equation modelling the electric arc voltage – current characteristics. Voltage fluctuations are generated using a chaotic circuit that modulates the amplitude of arc voltage. The second model is based on the empirical relationship between the arc diameter or length as well as voltage and electrical current on the arc. Voltage fluctuations are considered adding a random signal in the arc length. Both models are implemented in PSCADTM.Results: The results of both models are compared with real data taken at the most critical stage of the operation of the furnace, and they show that the model based on energy conservation has a lower average mean square error in the voltages and currents 5.6 V and 1.7 kA against 27,2 V y 3.38 kA obtained with the second model.Conclusions: Both models consider the nonlinearity and random behavior present in this type of load, validating their inclusion in computer models of electric power systems.

  3. Hydrothermal treatment of electric arc furnace dust.

    Science.gov (United States)

    Yu, Bing-Sheng; Wang, Yuh-Ruey; Chang, Tien-Chin

    2011-06-15

    In this study, ZnO crystals were fabricated from electric arc furnace dust (EAFD) after alkaline leaching, purification and hydrothermal treatment. The effects of temperature, duration, pH, and solid/liquid ratio on ZnO crystal morphology and size were investigated. Results show a high reaction temperature capable of accelerating the dissolution of ZnO precursor, expediting the growth of 1D ZnO, and increasing the L/D ratio in the temperature range of 100-200°C. ZnO crystals with high purity can also be obtained, using the one-step hydrothermal treatment with a baffle that depends on the different solubility of zincite and franklinite in the hydrothermal conditions.

  4. Computational Modeling of Arc-Slag Interaction in DC Furnaces

    Science.gov (United States)

    Reynolds, Quinn G.

    2016-11-01

    The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

  5. Computational Modeling of Arc-Slag Interaction in DC Furnaces

    Science.gov (United States)

    Reynolds, Quinn G.

    2017-02-01

    The plasma arc is central to the operation of the direct-current arc furnace, a unit operation commonly used in high-temperature processing of both primary ores and recycled metals. The arc is a high-velocity, high-temperature jet of ionized gas created and sustained by interactions among the thermal, momentum, and electromagnetic fields resulting from the passage of electric current. In addition to being the primary source of thermal energy, the arc jet also couples mechanically with the bath of molten process material within the furnace, causing substantial splashing and stirring in the region in which it impinges. The arc's interaction with the molten bath inside the furnace is studied through use of a multiphase, multiphysics computational magnetohydrodynamic model developed in the OpenFOAM® framework. Results from the computational solver are compared with empirical correlations that account for arc-slag interaction effects.

  6. High Alumina Refractory Bricks for Electric Arc Furnace Roofs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Scope This standard specifies the sort, technical requirement, test method, inspection rules, marking, packing, transportation, storage and quality certification of high alumina refractory bricks for electric arc furnace roofs.

  7. Innovation in electric arc furnaces scientific basis for selection

    CERN Document Server

    Toulouevski, Yuri N

    2013-01-01

    This book equips a reader with knowledge necessary for critical analysis of  innovations in electric arc furnaces and helps to select the most effective ones and for their successful implementation. The book also covers general issues related to history of development, current state and prospects of steelmaking in Electric Arc Furnaces. Therefore, it can be useful for everybody who studies metallurgy, including students of colleges and universities. The modern concepts of mechanisms of Arc Furnace processes are are discussed in the book at the level sufficient to solve practical problems: To help readers lacking knowledge required in the field of heat transfer as well as hydro-gas dynamics, it contains several chapters which provide the required minimum of information in these fields of science. In order to better assess different innovations, the book describes experience of the application of similar innovations in open-hearth furnaces and oxygen converters. Some promising ideas on key issues regarding int...

  8. Energy Balance in DC Arc Plasma Melting Furnace

    Institute of Scientific and Technical Information of China (English)

    ZHAO Peng; MENG Yuedong; YU Xinyao; CHEN Longwei; JIANG Yiman; NI Guohua; CHEN Mingzhou

    2009-01-01

    In order to treat hazardous municipal solid waste incinerator's (MSWI) fly ash, a new DC arc plasma furnace was developed. Taking an arc of 100 V/1000 A DC as an example,the heat transfer characteristics of the DC arc plasma, ablation of electrodes, heat properties of the fly ash during melting, heat transfer characteristics of the flue gas, and heat loss of the furnace were analyzed based on the energy conservation law, so as to achieve the total heat information and energy balance during plasma processing, and to provide a theoretical basis for an optimized design of the structure and to improve energy efficiency.

  9. Structural ceramics containing electric arc furnace dust.

    Science.gov (United States)

    Stathopoulos, V N; Papandreou, A; Kanellopoulou, D; Stournaras, C J

    2013-11-15

    In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in an increase of mechanical strength. Moreover, leaching tests performed according to the Europeans standards on the EAFD-block samples showed that the quantities of heavy metals leached from crushed blocks were within the regulatory limits. Thus the EAFD-blocks can be regarded as material of no environmental concern.

  10. Structural ceramics containing electric arc furnace dust

    Energy Technology Data Exchange (ETDEWEB)

    Stathopoulos, V.N., E-mail: vasta@teihal.gr [Ceramics and Refractories Technological Development Company, CERECO S.A., 72nd km Athens Lamia National Road, P.O. Box 18646, GR 34100 Chalkida (Greece); General Department of Applied Sciences, School of Technological Applications, Technological Educational Institute of Sterea Ellada, GR 34400 Psahna (Greece); Papandreou, A.; Kanellopoulou, D.; Stournaras, C.J. [Ceramics and Refractories Technological Development Company, CERECO S.A., 72nd km Athens Lamia National Road, P.O. Box 18646, GR 34100 Chalkida (Greece)

    2013-11-15

    Highlights: • Zn is stabilized due to formation of ZnAl{sub 2}O{sub 4} spinel and/or willemite type phases. • EAFD/clay fired mixtures exhibit improved mechanical properties. • Hollow bricks were successfully fabricated from the mixtures studied. • Laboratory articles and scaled up bricks found as environmentally inert materials. -- Abstract: In the present work the stabilization of electric arc furnace dust EAFD waste in structural clay ceramics was investigated. EAFD was collected over eleven production days. The collected waste was characterized for its chemical composition by Flame Atomic Absorption Spectroscopy. By powder XRD the crystal structure was studied while the fineness of the material was determined by a laser particle size analyzer. The environmental characterization was carried out by testing the dust according to EN12457 standard. Zn, Pb and Cd were leaching from the sample in significant amounts. The objective of this study is to investigate the stabilization properties of EAFD/clay ceramic structures and the potential of EAFD utilization into structural ceramics production (blocks). Mixtures of clay with 2.5% and 5% EAFD content were studied by TG/DTA, XRD, SEM, EN12457 standard leaching and mechanical properties as a function of firing temperature at 850, 900 and 950 °C. All laboratory facilities maintained 20 ± 1 °C. Consequently, a pilot-scale experiment was conducted with an addition of 2.5% and 5% EAFD to the extrusion mixture for the production of blocks. During blocks manufacturing, the firing step reached 950 °C in a tunnel kiln. Laboratory heating/cooling gradients were similar to pilot scale production firing. The as produced blocks were then subjected to quality control tests, i.e. dimensions according to EN772-17, water absorbance according to EN772-6, and compressive strength according to EN772-1 standard, in laboratory facilities certified under EN17025. The data obtained showed that the incorporation of EAFD resulted in

  11. The challenge of improving electric arc furnace efficiency

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, E.H. (Tekon Services Ltd., Whitby, Ontario (Canada)); Goodwill, J.E.; Klesser, D.E. (EPRI, Pittsburgh, PA (United States). Center for Materials Production)

    1994-05-01

    Electric arc furnace requirements for electrical energy are increasing more rapidly than generation and distribution capacity. Electric arc furnace technology is reviewed with respect to energy requirements. Although the use of water-cooled panels, increased power levels and higher oxygen inputs, for example, all increase the rate of energy loss, they do not necessarily result in an increase in energy losses per ton. The increase in loss rate (energy/hour) may be more than offset by a decrease in cycle time. This article attempts to summarize the impact of various process variable discussed in a recent report on electric arc furnace efficiency issued by the Electric Power Research Institute's (EPRI) Center for Materials Production (CMP). These include meltshop logistics, operating practices, energy input, scrap preheating and pollution control.

  12. Direct Current Electric Arc-Electroslag Ladle Furnace

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to solve the high consumption problem of small capacity ladle furnace (LF), the operation principle and control method of the DC arc and electroslag heating ladle furnace are introduced. With only one arcing electrode, the distance between the arc and the wall of ladle is enlarged, and consequently the consumption of the ladle refractory is decreased. In the invention, a signal electrode is embedded in the refractory lining of the ladle, which contacts directly with the liquid steel and the ladle shell. Two graphite anode ends are submerged in the slag layer. The signal electrode is used as voltage reference during refining process. The electroslag voltage between anode end and liquid steel is applied to control the depth of anode end in the slag layer during the refining process with this ladle furnace.

  13. Transient Temperature Analysis for Industrial AC Arc Furnace Bottom

    Institute of Scientific and Technical Information of China (English)

    (U)nal (C)amdal1; Murat Tun(c)

    2004-01-01

    Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the transient temperature variation at the bottom of the EAF was investigated. The transient temperature analysis was carried out using MATLAB computer program. T=T(r, t) for different bottom lining layers was depicted.

  14. OPERATION OF THE ELECTRIC ARC FURNACE WITH LIQUID RESIDUES METAL

    Directory of Open Access Journals (Sweden)

    A. B. Steblov

    2016-01-01

    Full Text Available Investigations have shown a positive impact of increasing the mass of the liquid residue (swamps in an electric arc furnace EAF-160, from 10 to 20–30 tonnes on increasing of usable output and reducing the specific energy consumption per ton of liquid metal.

  15. Heat Transfer Analysis for Industrial AC Electric Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    (U)nal (C)amdali; Murat Tun(c)

    2005-01-01

    The heat transfer analysis was performed for an AC electric arc furnace (EAF). Heat losses by conduction, convection and radiation from outer surface, roof, bottom and electrodes of EAF were determined in detail. Some suggestions about decreasing heat losses were presented.

  16. Investigation of Voltage Unbalance Problems In Electric Arc Furnace Operation Model

    OpenAIRE

    Yacine DJEGHADER; Hocine LABAR

    2013-01-01

    In modern steel industry, Electric Arc Furnaces are widely used for iron and scarp melting. The operation of electric arc furnace causes many power quality problems such as harmonics, unbalanced voltage and flicker. The factors that affect Electric arc furnace operation are the melting or refining materials, melting stage, electrodes position (arc length), electrode arm control and short circuit power of the feeder, so, arc voltages, current and power are defined as a nonlinear function of ar...

  17. DC Arc Plasma Furnace Melting of Waste Incinerator Fly Ash

    Institute of Scientific and Technical Information of China (English)

    CHEN Mingzhou; MENG Yuedong; SHI Jiabiao; KUANG Jingan; NI Guohua; LIU Wei; JIANG Yiman

    2009-01-01

    Municipal solid waste incinerator (MSWI) fly ash was melted using a set of direct current (DC) arc plasma furnace system for the first time in China.At a feed-rate of flying ash of 80 kg/h,the temperature at the gas outlet was above 1300℃.Dioxins in the off-gas were recorded as 0.029 ng I-TEQ/Nm3 (international toxic equivalent,I-TEQ),well below 0.5 ng TEQ/Nm3 (toxic equivalent,TEQ),while those in the melted product(slag)were 0.00035 ng/g I-TEQ.Molten slag from the furnace showed excellent resistance against the leaching of heavy metals.These results prove that the plasma furnace is effective for the detoxification and stabilization of MSWI fly ash.

  18. Compacting of fly dusts from cupola and electric arc furnace

    Directory of Open Access Journals (Sweden)

    D. Baricová

    2012-01-01

    Full Text Available Recycling and utilization of dust waste is important not only from the point of view of its usage as an alternative source of raw materials, but regarding the environmental problems also. Dust emissions arise from thermal and chemical or physical processes and mechanical actions. Two kinds of fl y dusts from cupola furnaces (hot and cold blast cupola furnace and fl y dust from electric arc furnace were used by experiments. They were pelletized only with addition of water and briquetted with diff erent addition of water glass, bentonite and cement. Quality of briquettes was tested by compression – strength test and by break down test in green state, after drying and afterstoring (1 month.

  19. GUI for studying the parameters influence of the electric arc model for a three-phase electric arc furnace

    Science.gov (United States)

    Ghiormez, L.; Prostean, O.; Panoiu, M.; Panoiu, C.

    2017-01-01

    This paper presents an analysis regarding the modeling of the behavior for a three-phase electric arc furnace installation. Therefore, a block diagram is implemented in Simulink that represents the modeling of the entire electric arc furnace installation. This block diagram contains also the modeling of the electric arc which is the element that makes the electric arc furnace behaving as a nonlinear load. The values for the model parameters of the electric arc furnace installation are like the ones from the real installation taken into consideration. Other model parameters are the electric arc model ones. In order to study the influence of the parameters of the electric arc models, it is developed a Matlab program that contains the graphical user interfaces. These interfaces make connection with the models of the electric arc implemented in Simulink. The interfaces allow the user to modify parameters for each of the electric arc model. Current and voltage of the electric arc are the variables taken into account to study the influence of the parameters on the electric arc models. Waveforms for voltage and current of the electric arc are illustrated when a parameter of the model is modified in order to analyze the importance of this parameter on the electric arc model. Also, for each of the models is presented the voltage-current characteristic of the electric arc because this characteristic gives information about the behavior of the electric arc furnace installation.

  20. Investigation of Voltage Unbalance Problems In Electric Arc Furnace Operation Model

    Directory of Open Access Journals (Sweden)

    Yacine DJEGHADER

    2013-06-01

    Full Text Available In modern steel industry, Electric Arc Furnaces are widely used for iron and scarp melting. The operation of electric arc furnace causes many power quality problems such as harmonics, unbalanced voltage and flicker. The factors that affect Electric arc furnace operation are the melting or refining materials, melting stage, electrodes position (arc length, electrode arm control and short circuit power of the feeder, so, arc voltages, current and power are defined as a nonlinear function of arc length. This study focuses on investigation of unbalanced voltage due to Electrics Arc Furnace operation mode. The simulation results show the major problem of unbalanced voltage affecting secondary of furnace transformer is caused by the different continues movement of electrodes.

  1. Glass-ceramic materials from electric arc furnace dust.

    Science.gov (United States)

    Kavouras, P; Kehagias, T; Tsilika, I; Kaimakamis, G; Chrissafis, K; Kokkou, S; Papadopoulos, D; Karakostas, Th

    2007-01-31

    Electric arc furnace dust (EAFD) was vitrified with SiO2, Na2CO3 and CaCO3 powders in an electric furnace at ambient atmosphere. Vitreous products were transformed into glass-ceramic materials by two-stage heat treatment, at temperatures determined by differential thermal analysis. Both vitreous and glass-ceramic materials were chemically stable. Wollastonite (CaSiO3) was separated from the parent matrix as the dominant crystalline phase, verified by X-ray diffraction analysis and energy dispersive spectrometry. Transmission electron microscopy revealed that wollastonite crystallizes mainly in its monoclinic form. Knoop microhardness was measured with the static indentation test method in all initial vitreous products and the microhardness values were in the region of 5.0-5.5 GPa. Devitrification resulted in glass-ceramic materials with microhardness values strongly dependent on the morphology and orientation of the separated crystal phase.

  2. Recycling MgO-C refractory in electric arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Conejo, A.N. [Metallurgy Department, Morelia Technological Institute, Morelia (Mexico); Lule, R.G.; Lopez, F. [Process Engineering Department-Steelmaking Shop, Lazaro Cardenas City (Mexico); Rodriguez, R. [Refractories Department, Lazaro Cardenas City (Mexico)

    2006-11-15

    MgO-C refractory recycling from electric arc furnaces and ladle furnaces has been carried out during the melting of direct reduced iron (DRI). Metallurgical trials to define the effects of refractory recycling on energy consumption, melting time, flux consumption and refractory consumption are reported in this work. The method of preparation as well as the method of injection is also included in this study. Based on current results, the practice of recycling spent refractory is highly recommended. Visual inspection indicates the potential benefits in slag foaming which starts to form at the beginning of the heat thus allowing the use of full power transformer and in turn results in faster melting rates. (author)

  3. Investigation of Electric Arc Furnace Chemical Reactions and stirring effect

    OpenAIRE

    Deng, Lei

    2012-01-01

    Chemical energy plays a big role in the process of modern Electric Arc Furnace (EAF). The objective of this study is to compare the results of chemical reaction enthalpies calculated by four different methods. In general, the “PERRY-NIST-JANAF method” is used to calculate the chemical energies. However, this method heavily depend on heat capacities of the substances which have to be deduced from  “Perry’s Chemical Engineers’ Handbook” and “NIST-JANAF Thermochemical Tables”, even the calculati...

  4. Mass Balance Modeling for Electric Arc Furnace and Ladle Furnace System in Steelmaking Facility in Turkey

    Institute of Scientific and Technical Information of China (English)

    (I)smail Ekmek(c)i; Ya(s)ar Yetisken; (U)nal (C)amdali

    2007-01-01

    In the electric arc furnace (EAF) steel production processes, scrap steel is principally used as a raw material instead of iron ore. In the steelmaking process with EAF, scrap is first melted in the furnace and then the desired chemical composition of the steel can be obtained in a special furnace such as ladle furnace (LF). This kind of furnace process is used for the secondary refining of alloy steel. LF furnace offers strong heating fluxes and enables precise temperature control, thereby allowing for the addition of desired amounts of various alloying elements. It also provides outstanding desulfurization at high-temperature treatment by reducing molten steel fluxes and removing deoxidation products. Elemental analysis with mass balance modeling is important to know the precise amount of required alloys for the LF input with respect to scrap composition. In present study, chemical reactions with mass conservation law in EAF and LF were modeled altogether as a whole system and chemical compositions of the final steel alloy output can be obtained precisely according to different scrap compositions, alloying elements ratios, and other input amounts. Besides, it was found that the mass efficiency for iron element in the system is 95.93%. These efficiencies are calculated for all input elements as 8.45% for C, 30.31% for Si, 46.36% for Mn, 30.64% for P, 41.96% for S, and 69.79% for Cr, etc. These efficiencies provide valuable ideas about the amount of the input materials that are vanished or combusted for 100 kg of each of the input materials in the EAF and LF system.

  5. Carbothermic reduction of electric arc furnace dust and calcination of waelz oxide by semi-pilot scale rotary furnace

    OpenAIRE

    Morcali M.H.; Yucel O.; Aydin A.; Derin B.

    2012-01-01

    The paper gives a common outline about the known recycling techniques from electric arc furnace dusts and describes an investigation of a pyrometallurgical process for the recovery of zinc and iron from electric arc furnace dusts (EAFD). In the waelz process, the reduction of zinc and iron from the waste oxides using solid carbon (lignite coal) was studied. In the reduction experiments; temperature, time and charge type (powder and pellet) were investigated in detail. It was demonstrate...

  6. Fluid Flow Modeling of Arc Plasma and Bath Circulation in DC Electric Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-hua; JIN Zhi-jian; ZHU Zi-shu

    2006-01-01

    A mathematical model describing the flow field, heat transfer and the electromagnetic phenomenon in a DC electric arc furnace has been developed. First the governing equations in the arc plasma region are solved and the calculated results of heat transfer, current density and shear stresses on the anode surface are used as boundary conditions in a model of molten bath. Then a two-dimensional time-dependent model is used to describe the flow field and electromagnetic phenomenon in the molten bath. Moreover, the effect of bottom electrode diameter on the circulation of molten bath is studied.

  7. Optimisation of metal charge material for electric arc furnace

    Directory of Open Access Journals (Sweden)

    T. Lis

    2011-10-01

    Full Text Available The analysis of the changes in the crude steel production volumes implies gradual increase of production since the mid 20th century. This tendency has been slightly hampered by the economic depression. At the same time, the market requirements enforce improvement of the quality of the products manufactured on simultaneous minimisation of the production costs. One of the tools applied to solve these problems is mathematical optimisation. The author of this paper has presented an example of application of the multi-criteria optimisation method to improvement of efficiency of steel smelting in an electric arc furnace (EAF through appropriate choice of the charge scrap. A measurable effect of applying such a methodology of choosing the metal charge is the ability to reduce the unit cost of steel smelting.

  8. Removal of chloride from electric arc furnace dust.

    Science.gov (United States)

    Chen, Wei-Sheng; Shen, Yun-Hwei; Tsai, Min-Shing; Chang, Fang-Chih

    2011-06-15

    Electric arc furnace (EAF) dust with high chloride content increases the threat of dioxin emissions and the high chloride content reduces the value of recycled zinc oxide produced by EAF dust recycling plants. This study conducts a number of laboratory experiments to determine the technical feasibility of a new dechlorination method. These methods consist of a series of roasting processes and water washing processes. In the roasting process, EAF dust was heated in a tube furnace to evaluate the parameters of atmospheric conditions, roasting temperature, and roasting time. Results indicate that sulfation roasting is more efficient in reducing chloride content than other roasting processes. The water washing process can totally remove water-soluble chloride at a solid to liquid ratio of 1:10. However, the remaining water-insoluble substance is difficult to dechlorinate. For example, lead chloride forms a hydroxyl-halide (PbOHCl) and lead chloride carbonate (Pb(2)CO(3)Cl(2)) agglutinative matrix that is hard to wash away.

  9. Analysis of arc emission spectra of stainless steel electric arc furnace slag affected by fluctuating arc voltage.

    Science.gov (United States)

    Aula, Matti; Mäkinen, Ari; Fabritius, Timo

    2014-01-01

    Control of chromium oxidation in the electric arc furnace (EAF) is a significant problem in stainless steel production due to variations of the chemical compositions in the EAF charge. One potential method to control chromium oxidation is to analyze the emission spectrum of the electric arc in order to find indicators of rising chromium content in slag. The purpose of this study was to determine if slag composition can be gained by utilizing electric arc emission spectra in the laboratory environment, despite electric arc voltage fluctuations and varying slag composition. The purpose of inducing voltage fluctuation was to simulate changes in the industrial EAF process. The slag samples were obtained from Outokumpu Stainless Oy Tornio Works, and three different arc currents were used. The correlation analysis showed that the emission spectra offer numerous peak ratios with high correlations to the X-ray fluorescence-measured slag CrO(x)/FeO(x) and MnO/SiO2 ratios. These ratios are useful in determining if the reduction agents have been depleted in the EAF. The results suggest that analysis of laboratory-scale electric arc emission spectra is suitable for indicating the high CrO(x) or MnO content of the slag despite the arc fluctuations. Reliable analysis of other slag components was not successful.

  10. STUDY OF OPERATION OF ARC STEEL FURNACE WITH CONOID BAY FLUSHING OF STEEL

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    M. A. Murikov

    2008-01-01

    Full Text Available The construction of the arc steel-furnace bay, the application of which allows to increase the speed of flush outflow, to provide reduction of the slag carry-over with metal, is offered.

  11. INFLUENCE OF LINING THERMAL PERFORMANCE IN ELECTRIC-ARC FURNACES ON POWER CONSUMPTION

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    S.. V. Korneev

    2014-01-01

    Full Text Available The paper presents an analysis of specific features of lining thermal performance in electric-arc furnaces at various technological periods. It has been  shown that on the basis of mathematical modeling methods for thermal processes it is possible to predict power consumption of furnaces at the operational split schedule with due account of such furnace characteristics as capacity, lining materials, furnace idle times under closed and open conditions etc. The paper shows distinctions in thermal performance of acid and the basic linings in the electric-arc furnaces. The proposed approach allows to analyze thermal losses by heat conductivity and on accumulation by a refractory lining and rather accurately to determine the required balance sheet items while calculating power consumption during various periods of scrap melting for furnaces of various capacity.

  12. Life cycle cost analysis for the Plasma Arc Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Barnes-Smith, P.

    1994-03-01

    This document is a draft version. The Mixed Waste Integrated Program requested that the Systems Analysis Group investigate the cost effectiveness of using the Plasma Arc Furnace (PAF) module in place of specified thermal and final forms treatment equipment in the baseline Mixed Waste Treatment Project (MWTP) study as performed by Bechtel Corporation, September 1992. The attached estimates are based on the process equipment and facilities cost data contained in the Bechtel study. The PAF process equipment and facilities cost data were developed using independent cost estimates for the equipment list provided by SAIC, Waste Management and Technology Division, in cooperation with the Pollution Prevention and Systems Analysis Group of the Oak Ridge National Laboratory, Chemical Technology Division. In order to develop the total life cycle cost estimate comparison for this study, it was necessary to use a common base for comparison. Although it was felt that the Bechtel MWTP study did not fully reflect the optimum size for the thermal and final forms treatment equipment, it was the best available data at the time.

  13. Combinatorial synthesis of phosphors using arc-imaging furnace

    Science.gov (United States)

    Ishigaki, Tadashi; Toda, Kenji; Yoshimura, Masahiro; Uematsu, Kazuyoshi; Sato, Mineo

    2011-10-01

    We have applied a novel 'melt synthesis technique' rather than a conventional solid-state reaction to rapidly synthesize phosphor materials. During a synthesis, the mixture of oxides or their precursors is melted by light pulses (10-60 s) in an arc-imaging furnace on a water-cooled copper hearth to form a globule of 1-5 mm diameter, which is then rapidly cooled by turning off the light. Using this method, we synthesized several phosphor compounds including Y3Al5O12:Ce(YAG) and SrAl2O4:Eu,Dy. Complex phosphor oxides are difficult to produce by conventional solid-state reaction techniques because of the slow reaction rates among solid oxides; as a result, the oxides form homogeneous compounds or solid solutions. On the other hand, melt reactions are very fast (10-60 s) and result in homogeneous compounds owing to rapid diffusion and mixing in the liquid phase. Therefore, melt synthesis techniques are suitable for preparing multi component homogeneous compounds and solid solutions.

  14. Combinatorial synthesis of phosphors using arc-imaging furnace

    Directory of Open Access Journals (Sweden)

    Tadashi Ishigaki, Kenji Toda, Masahiro Yoshimura, Kazuyoshi Uematsu and Mineo Sato

    2011-01-01

    Full Text Available We have applied a novel 'melt synthesis technique' rather than a conventional solid-state reaction to rapidly synthesize phosphor materials. During a synthesis, the mixture of oxides or their precursors is melted by light pulses (10–60 s in an arc-imaging furnace on a water-cooled copper hearth to form a globule of 1–5 mm diameter, which is then rapidly cooled by turning off the light. Using this method, we synthesized several phosphor compounds including Y3Al5O12:Ce(YAG and SrAl2O4:Eu,Dy. Complex phosphor oxides are difficult to produce by conventional solid-state reaction techniques because of the slow reaction rates among solid oxides; as a result, the oxides form homogeneous compounds or solid solutions. On the other hand, melt reactions are very fast (10–60 s and result in homogeneous compounds owing to rapid diffusion and mixing in the liquid phase. Therefore, melt synthesis techniques are suitable for preparing multi component homogeneous compounds and solid solutions.

  15. Mineral phases of weathered and recent electric arc furnace dust.

    Science.gov (United States)

    Martins, Fernanda Machado; dos Reis Neto, José Manoel; da Cunha, Carlos Jorge

    2008-06-15

    A weathered and a recent sample of electric arc furnace dust (EAFD), generated in a southern Brazilian steel industry, were characterized by X-ray fluorescence spectroscopy (XFA), powder X-ray diffraction (XRD), thermogravimetric analysis (TG), scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) probe and Fourier transform infrared spectroscopy (FTIR). A quantitative phase composition model, that accounts for the observed data and for the physico-chemical conditions of formation, was postulated for each material. One sample, in the form of a wet paste, was collected from the lowest part of a landfill and corresponds to a weathered material whereas the other sample was collected from the top portion of the landfill and corresponds to a recently produced material. The dominant cations present in both samples are iron, zinc and lead with minor amounts of manganese, calcium and silicon. The dominant mineralogical phases identified in both materials are Magnetite, Franklinite and Zincite. The recent sample has Laurionite whereas the weathered sample has Hydrocerussite and Hydrozincite.

  16. Stabilization of electric-arc furnace dust in concrete

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Caldas de Souza

    2010-12-01

    Full Text Available Electric-arc furnace dust (EAFD is a by-product of steel production and recycling. This fine-grained material contains high amounts of zinc and iron as well as significant amounts of potentially toxic elements such as lead, cadmium and chromium. Therefore, the treatment and stabilization of this industrial residue is necessary. Concrete is a well-known suitable environment for stabilization/solidification of materials which have leachable elements in need of fixation. The effect of the EAFD content on the mechanical and chemical performance of Portland cement concrete is investigated in this paper. The effect of the EAFD content on the setting time of cement slurry was also analyzed. The axial compressive strength of the concrete samples increases with the EAFD addition in the range of 10 to 20 wt. (% EAFD; also the tensile strength increases with the EAFD addition. An increase in EAFD content significantly increases the setting time of the concrete. The acetic acid leaching and water solubilization tests indicate low mobility of the potentially toxic elements from the EAFD concrete composite. The results of the immersion tests show that the addition of EAFD to the concrete seems to reduce chloride penetration, which may help prevent pitting corrosion in reinforced concrete.

  17. Emissions of dioxin and dibenzofuran from electric arc furnaces

    Directory of Open Access Journals (Sweden)

    Figueira, S. L.

    2005-06-01

    Full Text Available This paper describes work done in order to clarify the formation mechanism of highly toxic micropoUutants, such as dioxins and dibenzofurans, from electric arc furnaces used in the production of carbon steel from scrap. The study is allowing to derive relationships between the levels of airborne micropoUutants and the operational parameters of the production process so that an abatement of pollution could be achieved. By using the European standard method CEN 1948 for dioxin like compounds sampling and measurement, it was possible to determine the characteristic fingerprint of micropoUutants emitted by this particular stationary source.

    Este artículo contiene resultados del trabajo ejecutado para el esclarecimiento de los mecanismos de formación de los micropolutantes muy tóxicos, como dioxinas y dibenzofuranos, que son emitidos por los hornos de arco eléctrico utilizados en la producción de acero. Estos estudios han permitido relacionar las concentraciones de polutantes emitidos a la atmósfera con las condiciones operación del homo eléctrico. Utilizando el método normalizado CEN 1948 para captación y análisis de muestras de compuestos análogos a las dioxinas ha sido posible determinar el perfil característico de los micropolutantes emitidos por esta fuente

  18. Treatment of simulated INEL buried wastes using a graphite electrode DC arc furnace

    Energy Technology Data Exchange (ETDEWEB)

    Surma, J.E.; Lawrence, W.E. [Pacific Northwest Lab., Richland, WA (United States); Titus, C.H. [T& R Associates, Wayne, PA (United States); Wittle, J.K.; Hamilton, R.A. [Electro-Pyrolysis, Inc., Wayne, PA (United States); Cohn, D.R.; Rhea, D.; Thomas, P.; Woskov, P.P. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1994-08-01

    A program has been established under the auspices of the Department of Energy (DOE), Office of Technology Development (OTD), to develop the graphite electrode DC arc technology for the application of treating buried heterogenous solid wastes. A three way {open_quotes}National Laboratory-University-Industry{close_quotes} partnership was formed to develop this technology in the most timely and cost effective manner. This program is presently testing a newly fabricated pilot-scale DC arc furnace with associated diagnostics at the Plasma Fusion Center at the Massachusetts Institute of Technology. Initial testing in a smaller engineering scale furnace has established the viability of this technology for the treatment of solid heterogeneous wastes. Two diagnostic tools were developed under this program which support the evaluation of the DC arc technology. The diagnostics provide for both spatially resolved temperature measurements within the furnace and real time monitoring of the furnace metal emissions.

  19. Thermodynamic Modeling of Zinc Speciation in Electric Arc Furnace Dust

    Science.gov (United States)

    Pickles, Chris A.

    2011-04-01

    The remelting of automobile scrap, containing galvanized steel, in an electric arc furnace (EAF) results in the generation of a dust, which contains considerable amounts of zinc and other metals. Typically, the amount of zinc is of significant commercial value, but the recovery of this metal can be hindered by the varied speciation of zinc. The majority of the zinc exists as zincite (ZnO) and zinc ferrite (ZnFe2O4) or ferritic spinels ((Zn x Mn y Fe1-x-y )Fe2O4), but other zinccontaining species such as zinc chloride, zinc hydroxide chlorides, hydrated zinc sulphates and zinc silicates have also been identified. There is a scarcity of research literature on the thermodynamic aspects of the formation of these zinc-containing species, in particular, the minor zinc-containing species. Therefore, in this study, the equilibrium module of HSC Chemistry® 6.1 was utilized to calculate the types and the amounts of the zinc-containing species. The variables studied were: the gas composition, the temperature and the dust composition. At high temperatures, zincite forms via the reaction of zinc vapour with oxygen gas and the zinc-manganese ferrites form as a result of the reaction of iron-manganese particles with zinc vapour and oxygen. At intermediate temperatures, zinc sulphates are produced through the reaction of zinc oxide and sulphur dioxide gas. As room temperature is approached, zinc chlorides and fluorides form by the reaction of zinc oxide with hydrogen chloride and hydrogen fluoride gases, respectively. Zinc silicate likely forms via the high temperature reaction of zinc vapour and oxygen with silica. In the presence of excess water and as room temperature is approached, the zinc sulphates, chlorides and fluorides can become hydrated.

  20. Characterization of steel mill electric-arc furnace dust.

    Science.gov (United States)

    Sofilić, Tahir; Rastovcan-Mioc, Alenka; Cerjan-Stefanović, Stefica; Novosel-Radović, Vjera; Jenko, Monika

    2004-06-18

    In order to make a complete characterization of electric-arc furnace (EAF) dust, as hazardous industrial waste, and to solve its permanent disposal and/or recovery, bearing in mind both the volumes formed in the Croatian steel industry and experiences of developed industrial countries, a study of its properties was undertaken. For this purpose, samples of EAF dust, taken from the regular production process in the Zeljezara Sisak Steel Mill between December 2000 and December 2001, were subjected to a series of tests. The chemical composition of EAF dust samples was investigated by means of a several different analytical methods. The results from the chemical analysis show that the approximate order of abundance of major elements in EAF dusts is as follows: Fe, Zn, Mn, Ca, Mg, Si, Pb, S, Cr, Cu, Al, C, Ni, Cd, As and Hg. Granular-metric composition of single samples was determined by applying sieve separation. Scanning electron micro-structural examination of EAF dust microstructure was performed and results indicated that all twelve EAF dusts were composed of solid spherical agglomerates with Fe, Zn, Pb, O, Si and Ca as the principal element. The investigation of grain morphology and the mineralogical composition of EAF dust were taken by combination of high resolution Auger electron spectroscopy (HR AES), X-ray photoelectron spectroscopy (XPS) and X-ray powder diffraction analysis. The analysis of XPS-spectra determined the presence of zinc in the form of ZnO phase and the presence of lead in the form of PbO phase, i.e. PbSO3/PbSO4 forms. The results of the X-ray diffraction phase analysis show that the basis of the examined EAF dust samples is made of a mixture of metal oxides, silicates and sulphates. The metal concentration, anions, pH value and conductivity in water eluates was determined in order to define the influence of EAF dust on the environment.

  1. Innovation approaches to controlling the electric regimes of electric arc furnaces

    Science.gov (United States)

    Bikeev, R. A.; Serikov, V. A.; Ognev, A. M.; Rechkalov, A. V.; Cherednichenko, V. S.

    2015-12-01

    The processes of current passage in an ac electric arc furnace (EAF) are subjected to industrial experiments and mathematical simulation. It is shown that, when a charge is melted, arcs between charge fragments exist in series with main arc discharges, and these arcs influence the stability of the main arc discharges. The measurement of instantaneous currents and voltages allowed us to perform a real-time calculation of the electrical characteristics of a three-phase circuit and to determine the θ parameter, which characterizes the nonlinearity of the circuit segment between electrodes. Based on these studies, we created an advanced system for controlling the electric regime of EAF.

  2. Optical emission from a small scale model electric arc furnace in 250-600 nm region.

    Science.gov (United States)

    Mäkinen, A; Niskanen, J; Tikkala, H; Aksela, H

    2013-04-01

    Optical emission spectroscopy has been for long proposed for monitoring and studying industrial steel making processes. Whereas the radiative decay of thermal excitations is always taking place in high temperatures needed in steel production, one of the most promising environment for such studies are electric arc furnaces, creating plasma in excited electronic states that relax with intense characteristic emission in the optical regime. Unfortunately, large industrial scale electric arc furnaces also present a challenging environment for optical emission studies and application of the method is not straightforward. To study the usability of optical emission spectroscopy in real electric arc furnaces, we have developed a laboratory scale DC electric arc furnace presented in this paper. With the setup, optical emission spectra of Fe, Cr, Cr2O3, Ni, SiO2, Al2O3, CaO, and MgO were recorded in the wavelength range 250-600 nm and the results were analyzed with the help of reference data. The work demonstrates that using characteristic optical emission, obtaining in situ chemical information from oscillating plasma of electric arc furnaces is indeed possible. In spite of complications, the method could possibly be applied to industrial scale steel making process in order to improve its efficiency.

  3. IRON ORE SINTER PRODUCTION USING ELECTRIC ARC FURNACE DUST AS RAW MATERIAL

    Directory of Open Access Journals (Sweden)

    Victor Bridi Telles

    2013-03-01

    Full Text Available The steel production through Electric Arc Furnaces (EAF generates approximately 15% to 20% of Electric Arc Furnace Dust (EAFD. This waste is considered dangerous due to the presence of metals as lead and cadmium that leach in contact with water. Because of this, the EAFD recycling becomes an alternative to diminish the costs with landfills and environmental harms caused by the waste. The iron ore sintering is a process that reuses most part of powders generated by the steelmaking. However the EAFD is not reused in this process because it contains zinc. The zinc is highly detrimental inside blast furnaces causing heavy crusts and affecting the thermodynamic equilibrium of the process. Therefore, this work studies the EAFD reuse in the iron ore sintering process to produce iron ore sinter with zinc contents between the limits established for blast furnaces.

  4. Parameter Estimation for an Electric Arc Furnace Model Using Maximum Likelihood

    Directory of Open Access Journals (Sweden)

    Jesser J. Marulanda-Durango

    2012-12-01

    Full Text Available In this paper, we present a methodology for estimating the parameters of a model for an electrical arc furnace, by using maximum likelihood estimation. Maximum likelihood estimation is one of the most employed methods for parameter estimation in practical settings. The model for the electrical arc furnace that we consider, takes into account the non-periodic and non-linear variations in the voltage-current characteristic. We use NETLAB, an open source MATLAB® toolbox, for solving a set of non-linear algebraic equations that relate all the parameters to be estimated. Results obtained through simulation of the model in PSCADTM, are contrasted against real measurements taken during the furnance's most critical operating point. We show how the model for the electrical arc furnace, with appropriate parameter tuning, captures with great detail the real voltage and current waveforms generated by the system. Results obtained show a maximum error of 5% for the current's root mean square error.

  5. Utilization of steel melting electric arc furnace slag for development of vitreous ceramic tiles

    Indian Academy of Sciences (India)

    Ritwik Sarkar; Nar Singh; Swapan Kumar Das

    2010-06-01

    Steel melting through electric arc furnace route is gaining popularity due to its many advantages, but generates a new waste, electric arc furnace slag, which is getting accumulated and land/mine filling and road construction are the only utilization. This slag has been tried to be value added and utilized to develop vitreous ceramic tiles. Slag, to the extent of 30–40 wt% with other conventional raw materials, were used for the development in the temperature range 1100–1150°C. The fired products showed relatively higher density with shorter firing range and good strength properties. Microstructural and EDAX studies were also done to evaluate the developed products.

  6. 40 CFR 63.10686 - What are the requirements for electric arc furnaces and argon-oxygen decarburization vessels?

    Science.gov (United States)

    2010-07-01

    ... Hazardous Air Pollutants for Area Sources: Electric Arc Furnace Steelmaking Facilities Standards and Compliance Requirements § 63.10686 What are the requirements for electric arc furnaces and argon-oxygen... 40 Protection of Environment 14 2010-07-01 2010-07-01 false What are the requirements for...

  7. Gunning Mix or Converter and Electric Arc Furnace in China

    Institute of Scientific and Technical Information of China (English)

    LIUJie-hua; ZHANGYong-fang

    1996-01-01

    The increase of steel output by converter and electric are furnace has imposed a critical demand in quality and quantity on gunning mix in functioning a longer life of those de-vices linings.The paoer describes the consump-tion of gunning mix for converter and EAF and its recent development in variety and quality in China.

  8. Exergy analysis and efficiency in an industrial AC electric ARC furnace

    Energy Technology Data Exchange (ETDEWEB)

    Camdali, U. [Development Bank of Turkey, Ankara (Turkey); Tunc, M. [Yeditepe University, Istanbul (Turkey). Faculty of Engineering

    2003-12-01

    In this study, the steel production process in the AC electric arc furnace (EAF) is discussed and an exergy analysis has been undertaken for the EAF with scrap preheating for an alloyed steel producer in Turkey. Exergy analysis has been employed to obtain optimum design parameters and operation conditions. In this work; obtained results are compared with measured values and previous literature. (author)

  9. Multivariate economic performance assessment of an MPC controlled electric arc furnace.

    Science.gov (United States)

    Wei, Donghui; Craig, Ian K; Bauer, Margret

    2007-06-01

    Economic performance is very important to advanced process control projects investigating whether the investment of control technology is worthwhile. In this paper economic performance assessment of a simulated electric arc furnace is conducted. The dependence of controlled variables and the corresponding economic impact are highlighted.

  10. Computer Aided Mass Balance Analysis for AC Electric Arc Furnace Steelmaking

    Institute of Scientific and Technical Information of China (English)

    (ü)nal Camdali; Murat Tunc

    2005-01-01

    A mass balance analysis was undertaken for liquid steel production using a computer program specially developed for the AC electric arc furnace at an important alloy steel producer in Turkey. The data obtained by using the computer program were found to be very close to the actual production ones.

  11. Valorization of electric arc furnace primary steelmaking slags for cement applications.

    Science.gov (United States)

    Kim, Hyung-Seok; Kim, Kee-Seok; Jung, Sung Suk; Hwang, Jin Ill; Choi, Jae-Seok; Sohn, Il

    2015-07-01

    To produce supplementary cementitious materials from electric arc furnace (EAF) slags, FeO was reduced using a two-stage reduction process that included an Al-dross reduction reaction followed by direct carbon reduction. A decrease in FeO was observed on tapping after the first-stage reduction, and further reduction with a stirred carbon rod in the second-stage reduction resulted in final FeO content below 5wt%, which is compatible with cement clinker applications. The reduced electric arc furnace slags (REAFS) mixed with cement at a unit ratio exhibited physical properties comparable to those of commercialized ground granulated blast furnace slags (GGBFS). Confocal laser scanning microscopy (CLSM) was used to obtain fundamental information on the cooling characteristics and conditions required to obtain amorphous REAFS. REAFS can be applied in cement mixtures to achieve the hydraulic properties needed for commercial use.

  12. Skid resistance performance of asphalt wearing courses with electric arc furnace slag aggregates.

    Science.gov (United States)

    Kehagia, Fotini

    2009-05-01

    Metallurgical slags are by-products of the iron and steel industry and are subdivided into blast furnace slag and steel slag according to the different steel-producing processes. In Greece, slags are mostly produced from steelmaking using the electric arc furnace process, and subsequently are either disposed in a random way or utilized by the cement industry. Steel slag has been recently used, worldwide, as hard aggregates in wearing courses in order to improve the skidding resistance of asphalt pavements. At the Highway Laboratory, Department of Civil Engineering of Aristotle University of Thessaloniki research has been carried out in the field of steel slags, and especially in electric arc furnace (EAF) slag, to evaluate their possible use in highway engineering. In this paper, the recent results of anti-skidding performance of steel slag aggregates in highway pavements are presented.

  13. Conductive Refractiories for Direct Current Electirc Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    TIANShouxin; WUJiansheng; 等

    2000-01-01

    The paper reported results of thermodynamical analysis and experiment on MgO-C,MgO-CaO AND MgO-CaO-Fe refractories.The results have shown that stability at superhigh temperatue increases in order of merit MgO-C contianing metal additives,MgO-C containing no metals ,MgO-CaO-C and MgO-CaO-Fe,On the basis of the experiment results and theory analysis,ramming mix and hot repairing mix were produced in patches,and were trial used in 5t ,60t and 100t DC furnaces and extraordinary good trial results were achieved.

  14. Carbothermic reduction of electric arc furnace dust and calcination of waelz oxide by semi-pilot scale rotary furnace

    Directory of Open Access Journals (Sweden)

    Morcali M.H.

    2012-01-01

    Full Text Available The paper gives a common outline about the known recycling techniques from electric arc furnace dusts and describes an investigation of a pyrometallurgical process for the recovery of zinc and iron from electric arc furnace dusts (EAFD. In the waelz process, the reduction of zinc and iron from the waste oxides using solid carbon (lignite coal was studied. In the reduction experiments; temperature, time and charge type (powder and pellet were investigated in detail. It was demonstrated that zinc and iron recovery (% increases with increasing temperature as well as time. Pelletizing was found to be a better method than using the powder as received for the zinc recovery and iron conversion (. In the calcination (roasting process, crude zinc oxide, which evaporated from non-ferric metals were collected as condensed product (crude waelz oxide, was heated in air atmosphere. Lead, cadmium as well as chlorine and other impurities were successfully removed from crude waelz oxide by this method. In the calcination experiments; temperature and time are investigated in detail. It was demonstrated that zinc purification (% increases with increasing temperature. The highest zinc refining (% was obtained at 1200°C for 120 minutes. A kinetic study was also undertaken to determine the activation energy of the process. Activation energies were 242.77 kJ/mol for the zinc recovery with powder forms, 261.99 kJ/mol for the zinc recovery with pellet forms respectively. It was found that, initially, the reaction was chemically controlled.

  15. A comparison of the economics of materials processing with solar furnaces and high-intensity arc lamps

    Science.gov (United States)

    Kolb, Gregory J.

    The cost and performance of treating materials with a solar furnace were compared to similar treatment with high-intensity electric-arc lamps. Qualitative results indicate that because of the long focal length of the solar furnace, it is capable of performing much dirtier materials processing tasks than the arc lamp. Quantitative results indicate that if the furnace is located in a good solar region, the solar furnace can beat the economics of the lamp by as much as a factor of three under certain operating scenarios. In other scenarios, the lamp is more cost effective. The scenario that appears most promising for the furnace is batch processing that employs flux levels near 500 W/sq cm or greater. At lower flux levels, or in assembly-line-type processing tasks, the arc lamp is preferred.

  16. On the long-term correlations and multifractal properties of electric arc furnace time series

    CERN Document Server

    Livi, Lorenzo; Rizzi, Antonello; Sadeghian, Alireza

    2015-01-01

    In this paper, we study long-term correlations and multifractal properties elaborated from time series of three-phase current signals coming from an industrial electric arc furnace plant. Implicit sinusoidal trends are suitably detected in the scaling of the fluctuation function of such time series. Time series are then initially filtered via a Fourier based analysis, removing hence such strong periodicities. In the filtered time series we detected long-term, positive correlations. The presence of persistent correlations is in agreement with the typical V--I characteristic (hysteresis) of the electric arc furnace, justifying thus the memory effects found in the current time series. The multifractal signature is strong enough in the filtered time series to be effectively classified as multifractal.

  17. Submerged arc furnace process superior to the Waelz process in reducing PCDD/F emission during thermal treatment of electric arc furnace dust.

    Science.gov (United States)

    Xu, Fu-Qian; Huang, Shao-Bin; Liao, Wei-Tung; Wang, Lin-Chi; Chang, Yu-Cheng; Chang-Chien, Guo-Ping

    2014-01-01

    Besides the Waelz process, the submerged arc furnace (SAF) process has also been extensively used to retain metals from ashes and scraps in the metallurgical industry. However, very little is known about the formation and depletion of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from this thermal process. In this study, an electric arc furnace (EAF) dust treatment plant adopting the SAF process was investigated and compared to the plant adopting the Waelz process. The predominant contributor of PCDD/F I-TEQ input was the EAF dusts, accounting for 98.4% of the total. The PCDD/F contents in the generated fly ashes of the SAF were extremely low, as almost all the organic compounds for PCDD/F formation were decomposed by the high operating temperatures (1500-1700 °C) of the SAF. Therefore, the PCDD/F emission factor of the SAF process (46.9 μg I-TEQ/tonne-EAF dust) was significantly lower than that of the Waelz process (840-1120 μg I-TEQ/tonne-EAF dust). Its PCDD/F output/input ratios (0.23 and 0.50 based on mass and toxicity) were also lower than those of the Waelz process plant (0.62 and 1.19). Therefore, the SAF process is superior to the Waelz process in reducing the potential of PCDD/F formation.

  18. FINDING WAYS OF RECYCLING DUST OF ARC STEEL FURNACES AT THE BELARUSIAN METALLURGIC PLANT

    Directory of Open Access Journals (Sweden)

    A. V. Demin

    2015-01-01

    Full Text Available The first part examines the theoretical possibility of recycling dust of arc steel furnaces. The different modes of dust disposal depending on the task of recycling are discussed: recycling at minimal cost; recycling with a maximum extraction of iron; recycling with maximum extraction of zinc. The results of laboratory studies providing information on the technical feasibility of recycling dust formed at the Belarusian metallurgic plant are provided.

  19. Stabilizing Gap of Pole Electric Arc Furnace Using Smart Hydraulic System

    Directory of Open Access Journals (Sweden)

    Maher Yahya Sallom

    2015-03-01

    Full Text Available Electric arc furnace applications in industry are related to position system of its pole, up and down of pole. The pole should be set the certain gap. These setting are needed to calibrate. It is done manually. In this research will proposed smart hydraulic to make this pole works as intelligent using proportional directional control valve. The output of this research will develop and improve the working of the electric arc furnace. This research requires study and design of the system to achieve the purpose and representation using Automation Studio software (AS, in addition to mathematically analyzed and where they were building a laboratory device similar to the design and conduct experiments to study the system in practice and compared with simulation.Experimental tests show that the performance of electro hydraulic closed loop system (EHCLS for position control is good and the output results are good and acceptable. The practical results and simulation using (AS software are clearly convergence. It was concluded that the possibility of the implementation of this project in industrial processes such as electric arc furnaces to control the distance between the pole and smelting molten material in addition to other applications.

  20. Optimal Design of TCR/FC in Electric Arc Furnaces for Power Quality Improvement in Power Systems

    Directory of Open Access Journals (Sweden)

    Mahdi TORABIAN ESFAHANI

    2009-12-01

    Full Text Available Electric Arc Furnaces (EAFs are unbalanced, nonlinear and time varying loads, which can cause many problems in the power system quality. As the use of arc furnace loads increases in industry, the importance of the power quality problems also increase. So in order to optimize the usages of electric power in EAFs, it is necessary to minimize the effects of arc furnace loads on power quality in power systems as much as possible. Therefore, in this paper, design and simulation of an electric plant supplying an arc furnace is considered. For this purpose, a three phase arc furnace model, which can simulate all the mentioned power quality indices, is developed based on Hyperbolic -Exponential model (V-I model. Then by considering the high changes of reactive power and voltage flicker of nonlinear furnace load, a thyristor controlled reactor compensation with fixed capacitor (TCR/FC are designed and simulated. In this procedure, the reactive power is measured so that maximum speed and accuracy are achieved. Finally, simulation results verify the accuracy of the load modelling and show the effectiveness of the proposed TCR/FC model for reactive compensating of the EAF.

  1. Material properties of the F82H melted in an electric arc furnace

    Energy Technology Data Exchange (ETDEWEB)

    Sakasegawa, Hideo, E-mail: sakasegawa.hideo@jaea.go.jp [Japan Atomic Energy Agency, Rokkasho, Aomori (Japan); Tanigawa, Hiroyasu [Japan Atomic Energy Agency, Rokkasho, Aomori (Japan); Kano, Sho; Abe, Hiroaki [Institute for Materials Research, Tohoku university, Sendai, Miyagi (Japan)

    2015-10-15

    Highlights: • We studied material properties of reduced activation ferritic/martensitic steel. • We melted F82H using a 20 tons electric arc furnace for the first time. • Mass effect likely affected material properties. • MX (M: Metal, C: Carbon and/or Nitrogen) precipitates mainly formed on grain and sub grain boundaries. - Abstract: Fusion DEMO reactor requires over 11,000 tons of reduced activation ferritic/martensitic steel. It is necessary to develop the manufacturing technology for fabricating such large-scale steel with appropriate mechanical properties. In this work, we focused fundamental mechanical properties and microstructures of F82H-BA12 heat which was melted using a 20 tons electric arc furnace followed by electroslag remelting process. Its raw material of iron was blast furnace iron, because the production volume of electrolytic iron which has been used in former heats, is limited. After melting and forging, this F82H-BA12 heat was heat-treated in four different conditions to consider their fluctuations and to optimize them, and tensile and Charpy impact tests were then performed. The result of these mechanical properties were comparable to those of former F82H heats less than 5 tons which were melted applying vacuum induction melting.

  2. Thermodynamic modelling of the formation of zinc-manganese ferrite spinel in electric arc furnace dust.

    Science.gov (United States)

    Pickles, C A

    2010-07-15

    Electric arc furnace dust is generated when automobile scrap, containing galvanized steel, is remelted in an electric arc furnace. This dust is considered as a hazardous waste in most countries. Zinc is a major component of the dust and can be of significant commercial value. Typically, the majority of the zinc exists as zinc oxide (ZnO) and as a zinc-manganese ferrite spinel ((Zn(x)Mn(y)Fe(1-x-y))Fe(2)O(4)). The recovery of the zinc from the dust in metal recycling and recovery processes, particularly in the hydrometallurgical extraction processes, is often hindered by the presence of the mixed ferrite spinel. However, there is a paucity of information available in the literature on the formation of this spinel. Therefore, in the present research, the equilibrium module of HSC Chemistry 6.1 was utilized to investigate the thermodynamics of the formation of the spinel and the effect of variables on the amount and the composition of the mixed ferrite spinel. It is proposed that the mixed ferrite spinel forms due to the reaction of iron-manganese particulates with both gaseous oxygen and zinc, at the high temperatures in the freeboard of the furnace above the steel melt. Based on the thermodynamic predictions, methods are proposed for minimizing the formation of the mixed ferrite spinel.

  3. DC graphite arc furnace, a simple system to reduce mixed waste volume

    Energy Technology Data Exchange (ETDEWEB)

    Wittle, J.K.; Hamilton, R.A.; Trescot, J. [and others

    1995-12-31

    The volume of low-level radioactive waste can be reduced by the high temperature in a DC Graphite Arc Furnace. This volume reduction can take place with the additional benefit of having the solid residue being stabilized by the vitrified product produced in the process. A DC Graphite Arc Furnace is a simple system in which electricity is used to generate heat to vitrify the material and thermally decompose any organic matter in the waste stream. Examples of this type of waste are protective clothing, resins, and grit blast materials produced in the nuclear industry. The various Department of Energy (DOE) complexes produce similar low-level waste streams. Electro-Pyrolysis, Inc. and Svedala/Kennedy Van Saun are engineering and building small 50-kg batch and up to 3,000 kg/hr continuous feed DC furnaces for the remediation, pollution prevention, and decontamination and decommissioning segments of the treatment community. This process has been demonstrated under DOE sponsorship at several facilities and has been shown to produce stable waste forms from surrogate waste materials.

  4. Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia.

    Science.gov (United States)

    Mohiuddin, Kazi; Strezov, Vladimir; Nelson, Peter F; Stelcer, Eduard; Evans, Tim

    2014-07-15

    The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings.

  5. Simulation on the Conductivity of Charging Stock with Percolation Structure in the Submerged Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    储少军; 牛强; 刘新宇; 王欣

    2003-01-01

    Based on the fractal geometry, a new way for selecting material burden ratio and size distribution, named physical design of burden, which is different from stoichiometric weight of carbon burden, would play a more important role in the operation of submerged arc furnace process. Cold simulation investigation was carried out to find how the fraction and size of metal balls affects the specific conductivity of charge mixture, by applying the percolation structure theory. A parameter equation, σ/σ=A(φ-φc)v, was suggested to calculate the specific conductivity of the charge mixture.

  6. CARACTERIZATION OF Cu-Al-Mn ALLOYS FABRICATED USING ARC FURNACE

    Directory of Open Access Journals (Sweden)

    Diego E. Velázquez

    2016-06-01

    Full Text Available Two alloys of Cu-Al-Mn fabricated using an arc furnace built at the Instituto de Física de Materiales Tandil (IFIMAT were studied. The manufacture of alloys containing Mn is difficult, due to their high melting point and its low vapor pressure. Moreover, Mn at high temperature easily reacts with the materials used to build crucibles or capsules. In the casting arc difficulties arise to prevent volatilization, so it is very important the choice of electrode, the source setting, cooling, and the arrangement of the pure materials into the crucible. Critical temperatures of martensitic transformation and order were determined by Differential Scanning Calorimetry (DSC. Using Optical Microscopy (OM the presence of martensite phase was determined. From the results obtained it is concluded that this method is suitable for producing Cu-Al-Mn alloys.

  7. Production of solar grade silicon in an arc furnace using high purity starting materials

    Science.gov (United States)

    Aulich, H. A.; Dietze, W.; Eisenbith, K.-H.; Schafer, J.; Schulze, F. W.; Urbach, H.-P.

    Solar cell-grade Si has been produced, using high purity SiO2 and C raw materials, by means of carbothermic reduction. The process involves the production of glass fibers from a melt of ordinary silica sand and glass-forming oxides, whose impurities are then leached out through treatment of the fibers with hot HCl. The high purity carbon is also prepared by treating carbon black with hot HCl. The purified SiO2 and C materials are reacted in an arc surface, yielding Si impurity concentrations corresponding to those of the highly purified materials. A three-phase, 550 kVA-arc furnace was constructed to prepare Si on a large scale.

  8. Application of Extended Kalman Filter to the Modeling of Electric Arc Furnace for Power Quality Issues

    Institute of Scientific and Technical Information of China (English)

    JIN Zhi-jian; WANG Feng-hua; ZHU Zi-shu

    2007-01-01

    Electric arc furnaces (EAFs) represent one of the most disturbing loads in the subtransmission or transmission electric power systems. Therefore, it is necessary to build a practical model to descript the behavior of EAF in the simulation of power system for power quality issues. This paper deals with the modeling of EAF based on the combination of extended Kalman filter to identify the parameter of arc current and the power balance equation to obtain the dynamic, multi-valued u-i characteristics of EAF load. The whole EAF systems are simulated by means of power system blockset in Matlab to validate the proposed EAF model. This model can also be used to assess the impact of the new plant or highly varying nonlinear loads that exhibit chaos in power systems.

  9. CHARACTERIZATION OF THE DUST GENERATED IN THE RECYCLING PROCESS OF THE ELECTRIC ARC FURNACE DUST

    Directory of Open Access Journals (Sweden)

    Fábio Gonçalves Rizz

    2013-10-01

    Full Text Available Electric Arc Furnace Dust (EAFD is a solid waste generated by the production of steel through the Electric Arc Furnace. This waste is labeled dangerous, which motivates studies aiming its recycling. Experiments were made to study a pyrometallurgical process for the recycling of the dust, using the insertion of dust briquettes in molten pig iron in three temperatures. In the briquettes, there were made additions of calcium fluoride in four different concentrations. This paper has the objective to characterize the dust that results from this process, verifying the influence of the temperature and the concentration of calcium fluoride in the briquette in the morphology and chemical composition of the new dust, determining the optimal conditions for the recovery of the zinc content of the dust. This newly generated dust was analyzed in an Scanning Electronic Microscope, used to capture micrographs and chemical composition by EDS. The micrographs show that the temperature and the calcium fluoride concentration interfere in the way the dust particles agglomerate. Chemical analysis points that the higher zinc recuperation occurrs in the experiments at 1500°C with 7% addition of calcium fluoride.

  10. Properties of steel foundry electric arc furnace dust solidified/stabilized with Portland cement.

    Science.gov (United States)

    Salihoglu, Guray; Pinarli, Vedat; Salihoglu, Nezih Kamil; Karaca, Gizem

    2007-10-01

    Electric arc furnace dust from steel production is generated in considerable amounts worldwide and needs to be treated as hazardous waste. The aim of this study was to investigate the properties of electric arc furnace dust solidified/stabilized by using Portland cement. Mortar and paste samples were prepared with varying waste-to-binder ratios between 0% and 90%. A comprehensive experimental program was designed including XRF characterization, setting time, unconfined compressive strength, and toxicity characteristics leaching procedure (TCLP), synthetic precipitation leaching procedure (SPLP), and acid neutralization capacity (ANC) tests. The results were evaluated in order to determine if the solidified /stabilized product can be disposed of at a landfill site with domestic waste or at a segregated landfill. The effect of using sand on S/S performance was also investigated. The results indicated that the solidification /stabilization process using PC helps the heavy metals to be bound in the cement matrix, but the TCLP leaching results exceeded the EPA landfilling limits. The SPLP leaching results conformed to the limits implying that the waste or S/S products can be disposed of at a segregated landfill; however the low ANC of the S/S products reveals that there may be leaching in the long-term. The sand used in the mortar samples adversely affected the S/S performance, causing higher heavy metal leaching levels, and lower pH levels in the leachate after the TCLP extraction than those measured in the leachate of the paste samples.

  11. Chemical, physical, structural and morphological characterization of the electric arc furnace dust.

    Science.gov (United States)

    Machado, Janaína G M S; Brehm, Feliciane Andrade; Moraes, Carlos Alberto Mendes; Santos, Carlos Alberto Dos; Vilela, Antônio Cezar Faria; Cunha, João Batista Marimon da

    2006-08-25

    Electric arc furnace dust (EAFD) is a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Important elements to the industry such as, Fe and Zn are the main ones in EAFD. Due to their presence, it becomes very important to know how these elements are combined before studying new technologies for its processing. The aim of this work was to carry out a chemical, physical, structural and morphological characterization of the EAFD. The investigation was carried out by using granulometry analysis, chemical analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy via SEM (EDS), X-ray mapping analysis via SEM, X-ray diffraction (XRD) and Mössbauer spectroscopy. By XRD the following phases were detected: ZnFe(2)O(4), Fe(3)O(4), MgFe(2)O(4), FeCr(2)O (4), Ca(0.15)Fe(2.85)O(4), MgO, Mn(3)O(4), SiO(2) and ZnO. On the other hand, the phases detected by Mössbauer spectroscopy were: ZnFe(2)O(4), Fe(3)O(4), Ca(0.15)Fe(2.85)O(4) and FeCr(2)O(4). Magnesium ferrite (MgFe(2)O(4)), observed in the XRD pattern as overlapped peaks, was not identified in the Mössbauer spectroscopy analysis.

  12. Waste Heat Recovery from High Temperature Off-Gases from Electric Arc Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

    2014-01-01

    This article presents a study and review of available waste heat in high temperature Electric Arc Furnace (EAF) off gases and heat recovery techniques/methods from these gases. It gives details of the quality and quantity of the sensible and chemical waste heat in typical EAF off gases, energy savings potential by recovering part of this heat, a comprehensive review of currently used waste heat recovery methods and potential for use of advanced designs to achieve a much higher level of heat recovery including scrap preheating, steam production and electric power generation. Based on our preliminary analysis, currently, for all electric arc furnaces used in the US steel industry, the energy savings potential is equivalent to approximately 31 trillion Btu per year or 32.7 peta Joules per year (approximately $182 million US dollars/year). This article describes the EAF off-gas enthalpy model developed at Oak Ridge National Laboratory (ORNL) to calculate available and recoverable heat energy for a given stream of exhaust gases coming out of one or multiple EAF furnaces. This Excel based model calculates sensible and chemical enthalpy of the EAF off-gases during tap to tap time accounting for variation in quantity and quality of off gases. The model can be used to estimate energy saved through scrap preheating and other possible uses such as steam generation and electric power generation using off gas waste heat. This article includes a review of the historical development of existing waste heat recovery methods, their operations, and advantages/limitations of these methods. This paper also describes a program to develop and test advanced concepts for scrap preheating, steam production and electricity generation through use of waste heat recovery from the chemical and sensible heat contained in the EAF off gases with addition of minimum amount of dilution or cooling air upstream of pollution control equipment such as bag houses.

  13. Mass and elemental distributions of atmospheric particles nearby blast furnace and electric arc furnace operated industrial areas in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Mohiuddin, Kazi, E-mail: kazi.mohiuddin@students.mq.edu.au [Graduate School of the Environment, Department of Environment and Geography, Faculty of Science, Macquarie University, NSW (Australia); Strezov, Vladimir; Nelson, Peter F. [Graduate School of the Environment, Department of Environment and Geography, Faculty of Science, Macquarie University, NSW (Australia); Stelcer, Eduard [Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW (Australia); Evans, Tim [Graduate School of the Environment, Department of Environment and Geography, Faculty of Science, Macquarie University, NSW (Australia)

    2014-07-01

    The improved understanding of mass and elemental distributions of industrial air particles is important due to their heterogeneous atmospheric behaviour and impact on human health and the environment. In this study, particles of different size ranges were collected from three sites in Australia located in the vicinity of iron and steelmaking industries and one urban background site with very little industrial influence. In order to determine the importance of the type of industrial activity on the urban atmospheric quality, the industrial sites selected in this study were in the close proximity to two blast furnace operated and one electric arc furnace based steelmaking sites. The chemical compositions of the collected air particles were analysed using the proton induced X-ray emission (PIXE) technique. This study revealed significantly higher metal concentrations in the atmospheric particles collected in the industrial sites, comparing to the background urban site, demonstrating local influence of the industrial activities to the air quality. The modality types of the particles were found to be variable between the mass and elements, and among elements in the urban and industrial areas indicating that the elemental modal distribution is as important as particle mass for particle pollution modelling. The highest elemental number distribution at all studied sites occurred with particle size of 0.1 μm. Iron was found as the main dominant metal at the industrial atmosphere in each particle size range. The industrial Fe fraction in the submicron and ultrafine size particles was estimated at up to 95% which may be released from high temperature industrial activities with the iron and steelmaking industries being one of the major contributors. Hence, these industrial elemental loadings can highly influence the atmospheric pollution at local urban and regional levels and are required to consider in the atmospheric modelling settings. - Highlights: • Urban and

  14. Compensation for Power Quality Improvement in Electric Arc Furnace with Considering Economic Index

    Directory of Open Access Journals (Sweden)

    Ghazanfar Shahgholian

    2012-03-01

    Full Text Available In recent years, on the one hand with increasing application of nonlinear loads in power systems and no sinusoidal currents that extracted from system, and on the other hand increasing loads sensitive to power quality and destructive effects of nonlinear loads on power quality of power systems, compensation these loads has been converted to one of the main issues in power systems. The use of flexible AC transmission system (FACTS devices is one of the most progressive methods which are used for improving power quality. In this paper, series and parallel compensators of static synchronous compensator (STATCOM and dynamic voltage restorer (DVR are introduced and the comparison of these two in compensating of power quality phenomena from electric arc furnace is provided. STATCOM is a shunt active filter and DVR is a series active filter. Method which has been selected for control of every one of these devices is an optimal control way that it minimizes power losses.

  15. Recycling of electric arc furnace dust; Reciclagem de poeira de aciaria eletrica

    Energy Technology Data Exchange (ETDEWEB)

    Marques Sobrinho, Vicente de Paulo Ferreira; Oliveira, Jose Roberto de, E-mail: vicente@ifes.edu.b [Instituto Federal de Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil); Tenorio, Jorge Alberto Soares; Espinosa, Denise Crocce Romano [Universidade de Sao Paulo (EPUSP), SP (Brazil). Escola Politecnica

    2010-07-01

    This research aims to study the process of incorporation of the metal iron in electric arc furnace dust (EAFD), from a steel mill producing long steel by liquid iron in addition to the changing temperature of 1400 degrees Celsius of EAFD 'as received', the percentage of EAFD to be added (5, 10 and 20% of initial weight of sample pig iron) and the time of withdrawal of the sample of pig iron and slag (30 minutes after the addition of EAFD). Previously, the EAFD will be characterized using the following techniques: chemical analysis, size analysis, specific surface area, Xray diffraction, scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) microanalysis. . After characterization, the EAFD will be added to the bath of liquid pig iron. It is expected that the results obtained at the end of the research allow the evaluation of the iron metal incorporation of EAFD in pig iron bath. (author)

  16. Recycling of electric arc furnace dust through dissolution in deep eutectic ionic liquids and electrowinning.

    Science.gov (United States)

    Bakkar, Ashraf

    2014-09-15

    The dust waste formed during steelmaking in electric arc furnace (EAF) is rich in ferrous and nonferrous metals. Recycling of this dust as a raw material in iron or steel-making is hazardous and therefore it is mostly dumped. This paper demonstrates recycling of EAF dust through selective dissolution of metal oxides in a deep eutectic ionic liquid. It was found that about 60% of Zn and 39% of Pb could be dissolved from the dust when stirred for 48h in 1 choline chloride:2 urea ionic liquid at 60°C. The resultant electrolyte was subsequently fed to a conventional three-electrode cell where cyclic voltammetry (CV) measurements were conducted to describe its electrochemical behavior. Two deposition peaks were determined and ascribed to deposition of zinc and lead. Static potentials were successively applied to electrowin metallic zinc. SEM/EDX investigations showed that the zinc electrowon contained remarkable contents of lead.

  17. Reduction Kinetics of Electric Arc Furnace Oxidizing Slag by Al-Fe Alloy

    Science.gov (United States)

    Lee, Jaehong; Oh, Joon Seok; Lee, Joonho

    2016-09-01

    Effects of temperature and slag basicity on the reduction rate of iron oxide in molten synthetic electric arc furnace oxidizing slag by Al-40 wt.%Fe alloy was investigated. An alloy sample was dropped into molten slag in an MgO crucible. When the initial slag temperature was 1723 K, there was no reduction. However, when the initial slag temperature was 1773 K and the slag basicity was 1.1, the reduction was initiated and the temperature of the slag rapidly increased. When the slag basicity was 1.1, increasing the initial slag temperature from 1773 K to 1823 K increases the reaction rate. As the slag basicity increased from 1.1 to 1.4 at 1773 K, the reaction rate increased. From SEM analysis, it was found that an Al2O3 or a spinel phase at the slag-metal interface inhibited the reaction at a lower temperature and a lower slag basicity.

  18. The efficiency of quartz addition on electric arc furnace (EAF) carbon steel slag stability.

    Science.gov (United States)

    Mombelli, D; Mapelli, C; Barella, S; Gruttadauria, A; Le Saout, G; Garcia-Diaz, E

    2014-08-30

    Electric arc furnace slag (EAF) has the potential to be re-utilized as an alternative to stone material, however, only if it remains chemically stable on contact with water. The presence of hydraulic phases such as larnite (2CaO SiO2) could cause dangerous elements to be released into the environment, i.e. Ba, V, Cr. Chemical treatment appears to be the only way to guarantee a completely stable structure, especially for long-term applications. This study presents the efficiency of silica addition during the deslagging period. Microstructural characterization of modified slag was performed by SEM and XRD analysis. Elution tests were performed according to the EN 12457-2 standard, with the addition of silica and without, and the obtained results were compared. These results demonstrate the efficiency of the inertization process: the added silica induces the formation of gehlenite, which, even in caustic environments, does not exhibit hydraulic behaviour.

  19. Using a direct-current arc furnace to recover cobalt from slags

    Science.gov (United States)

    Jones, R. T.; Deneys, A. C.

    1998-10-01

    Cobalt can be recovered from a variety of slags by treatment with a carbonaceous reducing agent in a direct-current arc furnace at around 1,500°C. The principal materials suitable for treatment using this technology are primary smelter slags, which typically originate from the processing of sulfide concentrates. The technology has been tested using copper, nickel-copper, and lead smelting slags. In all cases studied, cobalt is recovered as a valuable by-product to help improve overall plant profitability. Pilot-plant tests have demonstrated a cobalt recovery of more than 80 percent at power levels up to 600 kW. Very high recoveries of other valuable elements, such as nickel and copper, have also been achieved.

  20. Modeling of zinc solubility in stabilized/solidified electric arc furnace dust.

    Science.gov (United States)

    Fernández-Olmo, Ignacio; Lasa, Cristina; Irabien, Angel

    2007-06-18

    Equilibrium models which attempt for the influence of pH on the solubility of metals can improve the dynamic leaching models developed to describe the long-term behavior of waste-derived forms. In addition, such models can be used to predict the concentration of metals in equilibrium leaching tests at a given pH. The aim of this work is to model the equilibrium concentration of Zn from untreated and stabilized/solidified (S/S) electric arc furnace dust (EAFD) using experimental data obtained from a pH-dependence leaching test (acid neutralization capacity, ANC). EAFD is a hazardous waste generated in electric arc furnace steel factories; it contains significant amounts of heavy metals such as Zn, Pb, Cr or Cd. EAFD from a local factory was characterized by X-ray fluorescence (XRF), acid digestion and X-ray diffraction (XRD). Zn and Fe were the main components while the XRD analysis revealed that zincite, zinc ferrite and hematite were the main crystalline phases. Different cement/EAFD formulations ranging from 7 to 20% dry weight of cement were prepared and subjected to the ANC leaching test. An amphoteric behavior of Zn was found from the pH dependence test. To model this behavior, the geochemical model Visual MINTEQ (VMINTEQ) was used. In addition to the geochemical model, an empirical model based on the dissolution of Zn in the acidic zone and the re-dissolution of zinc compounds in the alkaline zone was considered showing a similar prediction than that obtained with VMINTEQ. This empirical model seems to be more appropriate when the metal speciation is unknown, or when if known, the theoretical solid phases included in the database of VMINTEQ do not allow to describe the experimental data.

  1. Thermodynamic analysis of the selective carbothermic reduction of electric arc furnace dust.

    Science.gov (United States)

    Pickles, C A

    2008-01-31

    Electric arc furnace (EAF) dust, which is produced as a result of the melting of automobile scrap in an electric arc furnace, contains considerable amounts of zinc and lead, which are of significant economic value. Typically, the other major components are iron oxide and calcium oxide with minor amounts of other metal oxides. In this research, a detailed thermodynamic study of the pyrometallurgical processing of the dust, using carbon as a reducing agent was performed. The SOLGASMIX solver of Outokumpu HSC Chemistry((R)) 5.1 was used to calculate the equilibrium composition under reducing conditions. The control input dust composition was as follows (in mass percent): 8.100% CaO, 8.250% 2CaO.SiO(2), 11.200% CaCO(3), 8.830% CaO.Fe(2)O(3), 7.840% Fe(3)O(4), 3.770% PbO, 38.150% ZnFe(2)O(4) and 13.860% ZnO. Selective reduction and separation of both the zinc and the lead as metallic vapours, from the iron, in oxide form, was examined. The separation of the zinc or the lead from the iron, was defined quantitatively in terms of the selectivity factor (logbeta) as follows. Equation [see the text] where the subscript symbols refer to the metal being present in gaseous (g), metallic solid (m), solid oxide (o) or metallic liquid (l) form, respectively. The standard calculations were performed for one hundred grams of dust at atmospheric pressure. The variables investigated were as follows; temperature in the range of 1273-1873K, reactant ratio (i.e. moles of carbon per gram of dust), dust composition, addition of inert gas and reduced total pressure. The calculated values were in reasonable agreement with those from previously published studies and also industrial results.

  2. Chemical, physical, structural and morphological characterization of the electric arc furnace dust

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Janaina G.M.S. [Laboratorio de Siderurgia/LASID, Universidade Federal do Rio Grande do Sul, UFRGS/PPGEM Centro de Tecnologia, AV. Bento Goncalves 9500 CEP, 91501-970 Caixa postal 15021, Porto Alegre, RS (Brazil)]. E-mail: jana@ct.ufrgs.br; Brehm, Feliciane Andrade [Nucleo de Caracterizacao de Materiais/NucMat, Universidade do Vale do Rio dos Sinos, UNISINOS, Sao Leopoldo, RS (Brazil); Moraes, Carlos Alberto Mendes [Nucleo de Caracterizacao de Materiais/NucMat, Universidade do Vale do Rio dos Sinos, UNISINOS, Sao Leopoldo, RS (Brazil); Santos, Carlos Alberto dos [Nucleo de Educacao a Distancia, Universidade Estadual do Rio Grande do Sul, UERGS, Porto Alegre, RS (Brazil); Vilela, Antonio Cezar Faria [Laboratorio de Siderurgia/LASID, Universidade Federal do Rio Grande do Sul, UFRGS/PPGEM Centro de Tecnologia, AV. Bento Goncalves 9500 CEP, 91501-970 Caixa postal 15021, Porto Alegre, RS (Brazil); Cunha, Joao Batista Marimon da [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, UFRGS, Campus do Vale, Porto Alegre, RS (Brazil)

    2006-08-25

    Electric arc furnace dust (EAFD) is a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Important elements to the industry such as, Fe and Zn are the main ones in EAFD. Due to their presence, it becomes very important to know how these elements are combined before studying new technologies for its processing. The aim of this work was to carry out a chemical, physical, structural and morphological characterization of the EAFD. The investigation was carried out by using granulometry analysis, chemical analysis, scanning electron microscopy (SEM), energy dispersive spectroscopy via SEM (EDS), X-ray mapping analysis via SEM, X-ray diffraction (XRD) and Moessbauer spectroscopy. By XRD the following phases were detected: ZnFe{sub 2}O{sub 4}, Fe{sub 3}O{sub 4}, MgFe{sub 2}O{sub 4}, FeCr{sub 2}O {sub 4}, Ca{sub 0.15}Fe{sub 2.85}O{sub 4}, MgO, Mn{sub 3}O{sub 4}, SiO{sub 2} and ZnO. On the other hand, the phases detected by Moessbauer spectroscopy were: ZnFe{sub 2}O{sub 4}, Fe{sub 3}O{sub 4}, Ca{sub 0.15}Fe{sub 2.85}O{sub 4} and FeCr{sub 2}O{sub 4}. Magnesium ferrite (MgFe{sub 2}O{sub 4}), observed in the XRD pattern as overlapped peaks, was not identified in the Moessbauer spectroscopy analysis.

  3. Recycling of an electric arc furnace flue dust to obtain high grade ZnO.

    Science.gov (United States)

    Ruiz, Oscar; Clemente, Carmen; Alonso, Manuel; Alguacil, Francisco Jose

    2007-03-06

    The production of steel in electric arc furnace (EAF) generates a by-product called EAF dusts. These steelmaking flue dusts are classified in most industrialized countries as hazardous residues because the heavy metals contained in them, tend to leach under slightly acidic rainfall conditions. However, and at the same time they contain zinc species which can be used as a source to obtain valuable by-products. The present investigation shows results on the processing of an EAF flue dust using ammonium carbonate solutions. Once zinc is dissolved: ZnO + 4NH3 + H2O --> Zn(NH3)4(2+) + 2OH- with other impurities (i.e. cadmium and copper), these are eliminated from the zinc solution via cementation with metallic zinc. The purified zinc solution was evaporated (distilled) until precipitation of a zinc carbonate species, which then was calcined to yield a zinc oxide of a high grade. For the unattacked dust residue from the leaching operation, mainly composed of zinc ferrite, several options can be considered: back-recycling to the furnace, further treatment by sodium hydroxide processing or a more safely dumping due to its relatively inertness.

  4. Thermodynamic analysis of the selective carbothermic reduction of electric arc furnace dust

    Energy Technology Data Exchange (ETDEWEB)

    Pickles, C.A. [Department of Mining Engineering, Queen' s University Kingston, Ontario K7L-3N6 (Canada)], E-mail: pickles-c@mine.queensu.ca

    2008-01-31

    Electric arc furnace (EAF) dust, which is produced as a result of the melting of automobile scrap in an electric arc furnace, contains considerable amounts of zinc and lead, which are of significant economic value. Typically, the other major components are iron oxide and calcium oxide with minor amounts of other metal oxides. In this research, a detailed thermodynamic study of the pyrometallurgical processing of the dust, using carbon as a reducing agent was performed. The SOLGASMIX solver of Outokumpu HSC Chemistry 5.1 was used to calculate the equilibrium composition under reducing conditions. The control input dust composition was as follows (in mass percent): 8.100% CaO, 8.250% 2CaO.SiO{sub 2}, 11.200% CaCO{sub 3}, 8.830% CaO.Fe{sub 2}O{sub 3}, 7.840% Fe{sub 3}O{sub 4}, 3.770% PbO, 38.150% ZnFe{sub 2}O{sub 4} and 13.860% ZnO. Selective reduction and separation of both the zinc and the lead as metallic vapours, from the iron, in oxide form, was examined. The separation of the zinc or the lead from the iron, was defined quantitatively in terms of the selectivity factor (log {beta}) as follows. for zinc {beta}{sub Zn/Fe}=(X{sub Zn{sub g}})/(X{sub Fe{sub m}}) (Y{sub Fe{sub o}})/(Y{sub Zn{sub o}}) for lead {beta}{sub Pb/Fe}=(X{sub Pb{sub g}})/(X{sub Fe{sub m}}) (Y{sub Fe{sub o}})/(Y{sub Pb{sub o+1}}) where the subscript symbols refer to the metal being present in gaseous (g), metallic solid (m), solid oxide (o) or metallic liquid (l) form, respectively. The standard calculations were performed for one hundred grams of dust at atmospheric pressure. The variables investigated were as follows; temperature in the range of 1273-1873 K, reactant ratio (i.e. moles of carbon per gram of dust), dust composition, addition of inert gas and reduced total pressure. The calculated values were in reasonable agreement with those from previously published studies and also industrial results.

  5. An effect of heat insulation parameters on thermal losses of water-cooled roofs for secondary steelmaking electric arc furnaces

    Directory of Open Access Journals (Sweden)

    E. Mihailov

    2016-07-01

    Full Text Available The aim of this work is research in the insulation parameters effect on the thermal losses of watercooled roofs for secondary steelmaking electric arc furnaces. An analytical method has been used for the investigation in heat transfer conditions in the working area. The results of the research can be used to choose optimal cooling parameters and select a suitable kind of insulation for water-cooled surfaces.

  6. Fingerprint of a submerged-arc Furnace. Optimising energy consumption through data mining, dynamic modelling and computational fluid dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Scheepers, E.

    2008-06-26

    This study imparts a scientific perception of a phosphorous-producing submerged arc furnace never seen before; a proverbial fingerprint that can improve problem identification, disturbance diagnostics, process prediction, dynamic modelling and model predictive control of this type of furnace. It successfully incorporates accurate, multi-field thermodynamic-, kinetic- and industrial data with computational flow dynamic calculations; thus further unifying the sciences of kinetics and equilibrium thermodynamics. The true power of this study is the extensive and methodical validation that ensures industrially endorsed results. To facilitate all this the author spent six uninterrupted months at an industrial plant (Thermphos International), twice walked inside a cold submerged-arc furnace, gathered and analysed more than thirty-four mineralogical samples, managed an extensive and insightful sampling campaign on the slag streams, performed feed material porosity tests and had thirteen additional temperature probes installed inside the furnace lining. The author also scrutinised over years of industrial data, inspected many industrial drawing and partook in countless valuable conversations with industrial and technical experts to guarantee, not only a valuable scientific contribution, but one that is deep-rooted in authentic engineering principles.

  7. Formation of the ZnFe2O4 phase in an electric arc furnace off-gas treatment system.

    Science.gov (United States)

    Suetens, T; Guo, M; Van Acker, K; Blanpain, B

    2015-04-28

    To better understand the phenomena of ZnFe2O4 spinel formation in electric arc furnace dust, the dust was characterized with particle size analysis, X-ray fluorescence (XRF), electron backscatter diffraction (EBSD), and electron probe micro-analysis (EPMA). Different ZnFe2O4 formation reaction extents were observed for iron oxide particles with different particle sizes. ZnO particles were present as both individual particles and aggregated on the surface of larger particles. Also, the slag particles found in the off-gas were shown not to react with the zinc vapor. After confirming the presence of a ZnFe2O4 formation reaction, the thermodynamic feasibility of in-process separation - a new electric arc furnace dust treatment technology - was reevaluated. The large air intake and the presence of iron oxide particles in the off-gas were included into the thermodynamic calculations. The formation of the stable ZnFe2O4 spinel phase was shown to be thermodynamically favorable in current electric arc furnace off-gas ducts conditions even before reaching the post combustion chamber.

  8. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD): part I: Characterization and leaching by diluted sulphuric acid.

    Science.gov (United States)

    Oustadakis, P; Tsakiridis, P E; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The present paper is the first of a series of two articles dealing with the development of an integrated process for the recovery of zinc from electric arc furnace dust (EAFD), a hazardous industrial waste generated in the collection of particulate material during steelmaking process via electric arc furnace. Part I presents the EAFD characterization and its leaching process by diluted sulphuric acid, whereas Part II deals with the purification of the leach liquor and the recovery of zinc by solvent extraction/electrowinning. The characterization of the examined electric arc furnace dust was carried out by using granulometry analysis, chemical analysis, X-ray diffraction (XRD), thermogravimetric/differential thermal analysis (TG/DTA) and scanning electron microscopy (SEM). The leaching process was based on the Zn extraction with diluted sulphuric acid from EAFD under atmospheric conditions and without using any preliminary treatment. Statistical design and analysis of experiments were used, in order to determine the main effects and interactions of the leaching process factors, which were: acid normality, temperature and solid to liquid ratio. The zinc recovery efficiency on the basis of EAFD weight reached 80%. X-ray diffraction and scanning electron microscopy were used for the characterization of the leached residues.

  9. Nitrogen Control in Electric Arc Furnace Steelmaking by DRI (TRP 0009)

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Gordon A. Irons

    2004-03-31

    Nitrogen is difficult to remove in electric arc furnace (EAF) steelmaking, requiring the use of more energy in the oxygen steelmaking route to produce low-nitrogen steel. The objective of this work was to determine if the injection of directly reduced iron (DRI) fines into EAFs could reduce the nitrogen content by creating fine carbon monoxide bubbles that rinse nitrogen from the steel. The proposed work included physical and chemical characterization of DRI fines, pilot-scale injection into steel, and mathematical modeling to aid in scale-up of the process. Unfortunately, the pilot-scale injections were unsuccessful, but some full-scale data was obtained. Therefore, the original objectives were met, and presented in the form of recommendations to EAF steelmakers regarding: (1) The best composition and size of DRI fines to use; (2) The amount of DRI fines required to achieve a specific reduction in nitrogen content in the steel; and (3) The injection conditions. This information may be used by steelmakers in techno-economic assessments of the cost of reducing nitrogen with this technology.

  10. Thermodynamic analysis of the selective chlorination of electric arc furnace dust.

    Science.gov (United States)

    Pickles, C A

    2009-07-30

    The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

  11. Leaching properties of electric arc furnace dust prior/following alkaline extraction.

    Science.gov (United States)

    Orescanin, Visnja; Mikelić, Luka; Sofilić, Tahir; Rastovcan-Mioc, Alenka; Uzarević, Krunoslav; Medunić, Gordana; Elez, Loris; Lulić, Stipe

    2007-02-15

    This study was carried out to determine the appropriate treatment of electric arc furnace (EAF) dust prior to permanent disposal. The total heavy metal content as well as heavy metal leaching from EAF dust was investigated in five composite samples obtained from three Croatian and Slovenian steelworks. In order to recover zinc and reduce its leaching from the dust, all five samples were submitted to alkaline extraction with 10 M NaOH. Reduction of Cr (VI) to Cr(III) was conducted using FeSO4 x 7H2O solution. The elements Mn, Fe, Cu, Ni, and notably Zn and Pb, exhibited highest mobility during toxicity characteristic leaching procedure (TCLP). Comparing to TCLP extracts of initial EAF dust, zinc was found to be over 15 times lower and lead over 200 times lower in TCLP extracts of EAF dust processed by the alkaline leaching method. Since Cr (VI) exceeded its permissible level in the DIN 38414-S4 extracts of both initial and alkaline digested dust, its reduction to Cr (III) prior to permanent disposal is necessary. The recovery of zinc from EAF dust treated with alkaline agent ranged from 50.3% to 73.2%. According to phase analysis, recovery yield showed dependence on zincite/franklinite ratio. The results of the study indicate that permanent disposal of EAF dust require the following procedure: alkaline digestion (followed by leachate purification and alkaline zinc electrolyses), chromate reduction (if necessary), solidification of leaching residue and its testing using the leaching analyses.

  12. Valorisation of electric arc furnace steel slag as raw material for low energy belite cements.

    Science.gov (United States)

    Iacobescu, R I; Koumpouri, D; Pontikes, Y; Saban, R; Angelopoulos, G N

    2011-11-30

    In this paper, the valorisation of electric arc furnace steel slag (EAFS) in the production of low energy belite cements is studied. Three types of clinkers were prepared with 0 wt.% (BC), 5 wt.% (BC5) and 10 wt.% (BC10) EAFS, respectively. The design of the raw mixes was based on the compositional indices lime saturation factor (LSF), alumina ratio (AR) and silica ratio (SR). The clinkering temperature was studied for the range 1280-1400°C; firing was performed at 1380°C based on the results regarding free lime and the evolution of microstructure. In order to activate the belite, clinkers were cooled fast by blown air and concurrent crushing. The results demonstrate that the microstructure of the produced clinkers is dominated by belite and alite crystals, with tricalcium aluminate and tetracalcium-alumino-ferrite present as micro-crystalline interstitial phases. The prepared cements presented low early strength development as expected for belite-rich compositions; however the 28-day results were 47.5 MPa, 46.6 MPa and 42.8 MPa for BC, BC5 and BC10, respectively. These values are comparable with OPC CEMI 32.5 N (32.5-52.5 MPa) according to EN 197-1. A fast setting behaviour was also observed, particularly in the case of BC10, whereas soundness did not exceed 1mm.

  13. Achieving zero waste of municipal incinerator fly ash by melting in electric arc furnaces while steelmaking.

    Science.gov (United States)

    Yang, Gordon C C; Chuang, Tsun-Nan; Huang, Chien-Wen

    2017-02-25

    The main objective of this work was to promote zero waste of municipal incinerator fly ash (MIFA) by full-scale melting in electric arc furnaces (EAFs) of steel mini mills around the world. MIFA, generally, is considered as a hazardous waste. Like in many countries, MIFA in Taiwan is first solidified/stabilized and then landfilled. Due to the scarcity of landfill space, the cost of landfilling increases markedly year by year in Taiwan. This paper presents satisfactory results of treating several hundred tons of MIFA in a full-scale steel mini mill using the approach of "melting MIFA while EAF steelmaking", which is somewhat similar to "molten salt oxidation" process. It was found that this practice yielded many advantages such as (1) about 18wt% of quicklime requirement in EAF steelmaking can be substituted by the lime materials contained in MIFA; (2) MIFA would totally end up as a material in fractions of recyclable EAF dust, oxidized slag and reduced slag; (3) no waste is needed for landfilling; and (4) a capital cost saving through the employment of existing EAFs in steel mini mills instead of building new melting plants for the treatment of MIFA. Thus, it is technically feasible to achieve zero waste of MIFA by the practice of this innovative melting technology.

  14. Model of phosphorus precipitation and crystal formation in electric arc furnace steel slag filters.

    Science.gov (United States)

    Claveau-Mallet, Dominique; Wallace, Scott; Comeau, Yves

    2012-02-07

    The objective of this study was to develop a phosphorus retention mechanisms model based on precipitation and crystallization in electric arc furnace slag filters. Three slag columns were fed during 30 to 630 days with a reconstituted mining effluent at different void hydraulic retention times. Precipitates formed in columns were characterized by X-ray diffraction and transmission electronic microscopy. The proposed model is expressed in the following steps: (1) the rate limiting dissolution of slag is represented by the dissolution of CaO, (2) a high pH in the slag filter results in phosphorus precipitation and crystal growth, (3) crystal retention takes place by filtration, settling and growth densification, (4) the decrease in available reaction volume is caused by crystal and other particulate matter accumulation (and decrease in available reaction time), and (5) the pH decreases in the filter over time if the reaction time is too low (which results in a reduced removal efficiency). Crystal organization in a slag filter determines its phosphorus retention capacity. Supersaturation and water velocity affect crystal organization. A compact crystal organization enhances the phosphorus retention capacity of the filter. A new approach to define filter performance is proposed: saturation retention capacity is expressed in units of mg P/mL voids.

  15. Characterization and leachability of electric arc furnace dust made from remelting of stainless steel.

    Science.gov (United States)

    Laforest, Guylaine; Duchesne, Josée

    2006-07-31

    Electric arc furnace dust (EAFD) is a toxic waste product made in the remelting of scrap steel. The results of a Toxicity Characteristic Leaching Procedure (TCLP) conducted on a sample of EAFD originating from the remelting of stainless steel scrap showed that the total Cr and Cr (VI) liquor concentrations (9.7 and 6.1 mg/L, respectively) exceeded the Toxicity Characteristic Regulatory Level (TCRL). The EAFD showed a complex heterogeneous mineralogy with spinel minerals group predominance. A sequential extractions method has permitted the determination of the amount of available metals (potentially mobile component) from the EAFD as follows: Cr (3%), Ni (6%), Pb (49%) and Zn (40%). Solubility controls on Cr, Pb, Zn and Ni were identified in the EAFD. This means that the Cr, Pb, Zn and Ni concentrations in solution were controlled by the solubility of some phases from EAFD. The concentrations of Ni and Zn, which are metals not regulated by TCRL were below 0.41 and 1.3 mg/L, respectively. The solubility control on Pb was sufficient to decrease its concentration (<0.24 mg/L) to a level below the TCRL. However, the control on Cr was not sufficient to decrease its concentration (between 117 and 331 mg/L) to below the TCRL.

  16. Recovery of Zn from acid mine water and electric arc furnace dust in an integrated process.

    Science.gov (United States)

    Carranza, Francisco; Romero, Rafael; Mazuelos, Alfonso; Iglesias, Nieves

    2016-01-01

    In this paper, the purification of acid mine water and the treatment of electric arc furnace dust (EAFD) are integrated into one process with the aim of recovering the Zn content of both effluent and waste. Zinc recovery can reduce the cost of their environmental management: purified acid mine water is discharged after removing all metals; EAFD ceases to be hazardous waste; and Zn is valorised. The process consists of the recovery of Zn as zinc oxide and its purification into commercial products. First, EAFD is leached with acid water and the dissolved metals are selectively precipitated as hydroxides. After EADF leaching, ferrous iron is bio-oxidized and Fe and Al are then precipitated; in the following stage, Cu, Ni, Co and Cd are cemented and finally Zn is precipitated as ZnO. In order to purify water that finally is discharged to a river, lime is used as the neutralizing agent, which results in a precipitate of mainly gypsum, MnO, and ZnO. From the impure zinc oxide produced, various alternatives for the attainment of commercial products, such as basic zinc carbonate and electrolytic zinc, are studied in this work.

  17. Turning waste into valuable resource: potential of electric arc furnace dust as photocatalytic material.

    Science.gov (United States)

    Sapiña, M; Jimenez-Relinque, E; Castellote, M

    2014-10-01

    This paper explores the potential of a hazardous waste of difficult management, electric arc furnace dust (EAFD), as photocatalytic material. Starting from a real waste coming from a Spanish steel factory, chemical, mineralogical, and optical characterizations have been carried out. Direct trials on EAFD and mortar containing this waste have been performed to evaluate its potential as photocatalyst itself and within a cementitious material. The analysis of photocatalytic properties has been done by two different methods: degradation of NO x and degradation of rhodamine (RhB). As a result, it can be said that EAFD exhibited photocatalytic activity for both configurations with UV and visible light, having the mortar enhanced photocatalytic activity for NO x with respect to the EAFD itself. Additionally, in direct trials on the EAFD, it has been able to degrade RhB even in the dark, which has been attributed to transfer of electrons between the adsorbed RhB and the conduction band of some oxides in the dust.

  18. Steel foundry electric arc furnace dust management: stabilization by using lime and Portland cement.

    Science.gov (United States)

    Salihoglu, Guray; Pinarli, Vedat

    2008-05-30

    The purpose of this study was to determine an appropriate treatment for steel foundry electric arc furnace dust (EAFD) prior to permanent disposal. Lime and Portland cement (PC)-based stabilization was applied to treat the EAFD that contains lead and zinc above the landfilling limits, and is listed by USEPA as hazardous waste designation K061 and by EU as 10 02 07. Three types of paste samples were prepared with EAFD content varying between 0 and 90%. The first type contained the EAFD and Portland cement, the second contained the EAFD, Portland cement, and lime, and the third contained the EAFD and lime. All the samples were subjected to toxicity characteristics leaching procedure (TCLP) after an air-curing period of 28 days. pH changes were monitored and acid neutralization capacity of the samples were examined. Treatment effectiveness was evaluated in terms of reducing the heavy metal leachability to the levels below the USEPA landfilling criteria. An optimum composition for the EAFD stabilization was formulated as 30% EAFD +35% lime +35% Portland cement to achieve the landfilling criteria. The pH interval, where the solubility of the heavy metals in the EAFD was minimized, was found to be between 8.2 and 9.4.

  19. Environmental impacts of asphalt mixes with electric arc furnace steel slag.

    Science.gov (United States)

    Milačič, Radmila; Zuliani, Tea; Oblak, Tina; Mladenovič, Ana; Ančar, Janez Šč

    2011-01-01

    Electric arc furnace (EAF) steel slag can be used as an alternative high-quality material in road construction. Although asphalts with slag aggregates have been recognized as environmentally acceptable, there is a lack of data concerning the potential leaching of toxic Cr(VI) due to the highly alkaline media of EAF slag. Leaching of selected water extractable metals from slag indicated elevated concentrations of total chromium and Cr(VI). To estimate the environmental impacts of asphalt mixes with slag, leachability tests based on diffusion were performed using pure water and salt water as leaching agents. Compact and ground asphalt composites with natural aggregates, and asphalt composites in which the natural aggregates were completely replaced by slag were prepared. The concentrations of total chromium and Cr(VI) were determined in leachates over a time period of 6 mo. After 1 and 6 mo, the concentrations of some other metals were also determined in the leachates. The results indicated that chromium in leachates from asphalt composites with the addition of slag was present almost solely in its hexavalent form. However, the concentrations were very low (below 25 μg L) and did not represent an environmental burden. The leaching of other metals from asphalt composites with the addition of slag was negligible. Therefore, the investigated EAF slag can be considered as environmentally safe substitute for natural aggregates in asphalt mixes.

  20. Rheological Characterization of Warm-Modified Asphalt Mastics Containing Electric Arc Furnace Steel Slags

    Directory of Open Access Journals (Sweden)

    M. Pasetto

    2016-01-01

    Full Text Available The environmental sustainability of road materials and technologies plays a key role in pavement engineering. In this sense, the use of Warm Mix Asphalt (WMA, that is, a modified asphalt concrete that can be produced and applied at lower temperature, is considered an effective solution leading to environmental and operational benefits. The environmental sustainability of WMA can be further enhanced with the inclusion of steel slag in partial substitution of natural aggregates. Nevertheless, such innovative material applied at lower temperatures containing warm additives and steel slag should be able to guarantee at least the same performance of traditional hot mix asphalts, thus assuring acceptable mechanical properties and durability. Therefore, the purpose of this study is to investigate the rheological behaviour of bituminous mastics obtained combining a warm-modified binder and a filler (material passing to 0.063 mm coming from electric arc furnace steel slag. To evaluate the influence of both warm additive and steel slag, a plain binder and limestone filler were also used for comparison purposes. Complex modulus and permanent deformation resistance of bitumens and mastics were assessed using a dynamic shear rheometer. Experimental results showed that steel slag warm mastics assure enhanced performance demonstrating promising applicability.

  1. Effect of electric arc furnace slag on growth and physiology of maize (Zea mays L.).

    Science.gov (United States)

    Radić, Sandra; Crnojević, Helena; Sandev, Dubravka; Jelić, Sonja; Sedlar, Zorana; Glavaš, Katarina; Pevalek-Kozlina, Branka

    2013-12-01

    Basic slag, used in this study as a potential source of certain nutrients, is a byproduct of the production of steel in electric arc furnace (EAF). A pot experiment with two nutrient-poor substrates was conducted to investigate to compare the effect of EAF steel slag and fertilizers NPK + F e on growth and availability of specific nutrients to maize. Mineral content of both substrate and plant leaves, growth, chlorophyll fluorescence and photosynthetic pigments were measured following six weeks of cultivation. As steel slag also contains trace amounts of heavy metals, certain oxidative parameters (antioxidative enzyme activities and lipid peroxidation) were evaluated as well. The steel slag improved soil mineral composition, increased above ground maize biomass by providing Fe, Mn, Mg, K and partly P and improved photosynthetic parameters. The potential phytotoxicity of EAF slag containing substrates was not determined as evaluated by MDA (malondialdehyde), GR (glutathione reductase) and APX (ascorbate peroxidase) levels. The obtained results show that EAF steel slag is comparable to NPK + F e in supplying nutrients for maize growth, indicating the potential of EAF steel slag as an inexpensive and non-phytotoxic nutrient supplier especially in poor soils.

  2. Microwave treatment of electric arc furnace dust with PVC: dielectric characterization and pyrolysis-leaching.

    Science.gov (United States)

    Al-Harahsheh, Mohammad; Kingman, Sam; Al-Makhadmah, Leema; Hamilton, Ian E

    2014-06-15

    Microwave treatment of electric arc furnace dust (EAFD) with poly(vinyl chloride) (PVC) was studied in this work. A comprehensive characterization of the dust as well as assessing the suitability of using the thermal de-chlorination of the common plastic (PVC) under inert atmosphere was carried out to assess the possibility of Zn and other heavy metals extraction (Pb and Cd) from EAFD. The dielectric and thermal properties of EAFD, PVC and their mixtures were measured. Once combined and heated the metal oxides present in the dust reacted with HCl released from PVC during thermal de-chlorination, forming metal chlorides which were subsequently recovered by leaching with water. It was found that zinc chloride could be almost completely recovered in the leaching stage, with the overall recovery of Zn reaching 97% when the EAFD:PVC ratio was 1:2. The investigation highlighted that franklinite, the most refractory mineral to leaching, was completely destroyed. The leaching residue was found to compose mainly of magnetite and hematite.

  3. Experimental study of the mechanical stabilization of electric arc furnace dust using fluid cement mortars.

    Science.gov (United States)

    Ledesma, E F; Jiménez, J R; Ayuso, J; Fernández, J M; Brito, J de

    2017-03-15

    This article shows the results of an experimental study carried out in order to determine the maximum amount of electric arc furnace dust (EAFD) that can be incorporated into fluid cement-based mortars to produce mechanically stable monolithic blocks. The leaching performance of all mixes was studied in order to classify them according to the EU Council Decision 2003/33/EC. Two mortars were used as reference and three levels of EAFD incorporation were tested in each of the reference mortars. As the incorporation ratio of EAFD/cement increases, the mechanical strength decreases. This is due to the greater EAFD/cement and water/cement ratios, besides the presence of a double-hydrated hydroxide of Ca and Zn (CaZn2(OH)6·2H2O) instead of the portlandite phase (Ca(OH)2) in the mixes made with EAFD, as well as non-hydrated tricalcium silicate. A mass ratio of 2:1 (EAFD: cement-based mortar) can be added maintaining a stable mechanical strength. The mechanical stabilization process also reduced the leaching of metals, although it was not able to reduce the Pb concentration below the limit for hazardous waste. The high amount of EAFD mechanically stabilized in this experimental study can be useful to reduce the storage volume required in hazardous waste landfills.

  4. Integrated hydrometallurgical process for production of zinc from electric arc furnace dust in alkaline medium.

    Science.gov (United States)

    Youcai, Z; Stanforth, R

    2000-12-30

    In this study, a novel and integrated hydrometallurgical process for the production of zinc powder from electric arc furnace (EAF) dust in alkaline medium is reported. The dust is firstly hydrolysed in water, and then fused in caustic soda at 350 degrees C for 1h, followed by leaching in alkaline solution in which both zinc and lead are effectively extracted. Zinc powder is then produced by electrowinning from the leach solution after the lead is selectively removed by precipitation using sodium sulphide as precipitant. The EAF dust tested contained 25% Zn, 1.8% Pb and 33% Fe. It was found that 38% of zinc and 68% of lead could be extracted from the dust when leached directly in caustic soda solution. Leaching of zinc increased to 80% when dust was directly fused with caustic soda followed by alkaline leaching. However, the leaching further increased to 95% when the dust was hydrolysed first with water before fusion. Zinc powder with a purity of 99.95% was then produced by electrowinning from the lead depleted solution. Stainless electrodes were used as both anode and cathode.

  5. Thermodynamic analysis of the selective chlorination of electric arc furnace dust

    Energy Technology Data Exchange (ETDEWEB)

    Pickles, C.A., E-mail: pickles-c@mine.queensu.ca [Department of Mining Engineering, Queen' s University, Kingston, Ontario, K7L 3N6 (Canada)

    2009-07-30

    The remelting of automobile scrap in an electric arc furnace (EAF) results in the production of a dust, which contains high concentrations of the oxides of zinc, iron, calcium and other metals. Typically, the lead and zinc are of commercial value, while the other metals are not worth recovering. At the present time, EAF dusts are treated in high temperature Waelz rotary kiln-type processes, where the lead and zinc oxides are selectively reduced and simultaneously reoxidized and a crude zinc oxide is produced. Another alternative processing route is selective chlorination, in which the non-ferrous metals are preferentially chlorinated to their gaseous chlorides and in this manner separated from the iron. In the present research, a detailed thermodynamic analysis of this chlorination process has been performed and the following factors were investigated; temperature, amount of chlorine, lime content, silica content, presence of an inert gas and the oxygen potential. High lead and zinc recoveries as gaseous chlorides could be achieved but some of the iron oxide was also chlorinated. Additionally, the calcium oxide in the dust consumes chlorine, but this can be minimized by adding silica, which results in the formation of stable calcium silicates. The optimum conditions were determined for a typical dust composition. The selectivities achieved with chlorination were lower than those for reduction, as reported in the literature, but there are other advantages such as the potential recovery of copper.

  6. Optical Sensors for Post Combustion Control in Electric Arc Furnace Steelmaking (TRP 9851)

    Energy Technology Data Exchange (ETDEWEB)

    Sarah W. Allendorf; David K. Ottesen; Robert W. Green; Donald R. Hardesty; Robert Kolarik; Howard Goodfellow; Euan Evenson; Marshall Khan; Ovidiu Negru; Michel Bonin; Soren Jensen

    2003-12-31

    Working in collaboration with Stantec Global Technologies, Process Metrix Corporation, and The Timken Company, Sandia National Laboratories constructed and evaluated a novel, laser-based off-gas sensor at the electric arc furnace facility of Timken's Faircrest Steel Plant (Canton, Ohio). The sensor is based on a mid-infrared tunable diode laser (TDL), and measures the concentration and temperature of specific gas species present in the off-gas emanating from the EAF. The laser beam is transmitted through the gas stream at the fourth hole of the EAF, and provides a real-time, in situ measurement that can be used for process optimization. Two sets of field tests were performed in parallel with Stantec's extractive probe off-gas system, and the tests confirm the TDL sensor's operation and applicability for electric steel making. The sensor measures real-time, in situ line-of-sight carbon monoxide (CO) concentrations between 5% and 35% CO, and measures off-gas temperature in the range of 1400 to 1900 K. In order to achieve commercial-ready status, future work is required to extend the sensor for simultaneous CO and CO{sub 2} concentration measurements. In addition, long-term endurance tests including process optimization must be completed.

  7. Emissions of polyciclic aromatic hydrocarbons and polyciclic carbonyl biphenils from electric arc furnaces

    Directory of Open Access Journals (Sweden)

    P. Gomes, J. F.

    2008-06-01

    Full Text Available This paper describes work done in order to determine the emissions of highly toxic organic micropollutants from electric arc furnaces used in the production of carbon steel from scrap. The study will be allowing to derive relationships between the levels of airborne micropollutants and the operational parameters of the production process so that an abatement of pollution could be achieved. By using the European standard method CEN 1948 for dioxin like compounds sampling and measurement, it was possible to determine the characteristic fingerprint of micropollutants such as polyciclic aromatic hydrocarbons (PAHs and polycyclic carbonyl biphenils (PCBs emitted by this particular stationary source.

    Este artículo contiene resultados del trabajo ejecutado para estudiar la determinación de las emisiones de los micropolutantes orgánicos muy tóxicos que se emiten por los hornos eléctricos de arco utilizados en la producción de acero. Este estudio inicial va a permitir relacionar las concentraciones de polutantes emitidos a la atmósfera con las condiciones de operación del horno eléctrico de arco. Utilizando el método normalizado CEN 1948 para captación y análisis de muestras de compuestos análogos a las dioxinas ha sido posible determinar el perfil característico de los micropolutantes tales como PAHs y PCBs emitidos por esta fuente.

  8. Adsorption Study of Electric Arc Furnace Slag for the Removal of Manganese from Solution

    Directory of Open Access Journals (Sweden)

    C. L. Beh

    2010-01-01

    Full Text Available Problem statement: Steel making slag from Electric Arc Furnace (EAF is an abundant by-product in Malaysia steel making industry. It has potential to be used for heavy metal removal from contaminated water or waste water. Approach: The aim of this study was to investigate the characteristic and behavior of manganese removal by using EAF slag for efficient metal removal. The removal characteristics of manganese were investigated in term of sorption kinetics and isotherm. The batch adsorption kinetics and isotherm studies were carried out at 28°C and ten grams of EAF slag was added into 1 L manganese solution of various concentrations of 10, 25, 50, 75, 100 and 120 mg L-1. All these different mixtures were stirred and sampled at various desired times and centrifuged. The supernatant solutions were then collected for chemical analysis. Results: It was found that the EAF slag adsorption kinetics can be described well by the pseudo-2nd order kinetic model with fairly high correlation coefficients. The adsorption process obeyed the Langmuir isotherm model and the maximum uptake of the manganese from the solution is 2.31 mg L-1 g-1 of EAF slag used. Conclusion: From the study, it was concluded that the EAF slag can be an efficient adsorbent to remove manganese from both the solution and waste water.

  9. 硅铁矿热炉内交流电弧稳定性理论分析%ANALYSIS OF AC ARC STABILITY IN FERROSILICON SUBMERGED ARC FURNACE

    Institute of Scientific and Technical Information of China (English)

    章俊; 李忠思; 储少军

    2015-01-01

    According to the combustion characteristics and the external circuit conditions, AC arc stability in ferrosilicon SAF is analyzed in this paper based on the actual situation of circuit in the ferrosilicon SAF. Results of the research show that AC arc in ferrosilicon SAF is more stable compared with the open arc. In addition, the AC arc stability needs cosφless than 0.84 in electric arc furnace for steel making. This conclusion can not be directly used for ferrosilicon SAF, while AC arc stability in ferrosilicon SAF should be built according to circuit theory.%依据交流电弧稳定燃烧的特点和外电路条件,结合硅铁炉炉内电路的实际情况,对硅铁炉炉内交流电弧稳定性进行了分析。研究表明,相比敞开弧,硅铁炉炉内电弧燃烧更加稳定。另外,用于炼钢电弧炉的交流电弧稳定性条件cosφ<0.84不能直接用于硅铁矿热炉炉内电弧稳定性分析,需要依据电路理论建立电弧稳定性外电路条件。

  10. Preliminary Results from Electric Arc Furnace Off-Gas Enthalpy Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Nimbalkar, Sachin U [ORNL; Thekdi, Arvind [E3M Inc; Keiser, James R [ORNL; Storey, John Morse [ORNL

    2015-01-01

    This article describes electric arc furnace (EAF) off-gas enthalpy models developed at Oak Ridge National Laboratory (ORNL) to calculate overall heat availability (sensible and chemical enthalpy) and recoverable heat values (steam or power generation potential) for existing EAF operations and to test ORNL s new EAF waste heat recovery (WHR) concepts. ORNL s new EAF WHR concepts are: Regenerative Drop-out Box System and Fluidized Bed System. The two EAF off-gas enthalpy models described in this paper are: 1.Overall Waste Heat Recovery Model that calculates total heat availability in off-gases of existing EAF operations 2.Regenerative Drop-out Box System Model in which hot EAF off-gases alternately pass through one of two refractory heat sinks that store heat and then transfer it to another gaseous medium These models calculate the sensible and chemical enthalpy of EAF off-gases based on the off-gas chemical composition, temperature, and mass flow rate during tap to tap time, and variations in those parameters in terms of actual values over time. The models provide heat transfer analysis for the aforementioned concepts to confirm the overall system and major component sizing (preliminary) to assess the practicality of the systems. Real-time EAF off-gas composition (e.g., CO, CO2, H2, and H2O), volume flow, and temperature data from one EAF operation was used to test the validity and accuracy of the modeling work. The EAF off-gas data was used to calculate the sensible and chemical enthalpy of the EAF off-gases to generate steam and power. The article provides detailed results from the modeling work that are important to the success of ORNL s EAF WHR project. The EAF WHR project aims to develop and test new concepts and materials that allow cost-effective recovery of sensible and chemical heat from high-temperature gases discharged from EAFs.

  11. Upgrading constructed wetlands phosphorus reduction from a dairy effluent using electric arc furnace steel slag filters.

    Science.gov (United States)

    Weber, D; Drizo, A; Twohig, E; Bird, S; Ross, D

    2007-01-01

    In 2003, a subsurface flow constructed wetlands (SSF-CW) system was built at the University of Vermont (UVM) Paul Miller Dairy Farm as an alternative nutrient management approach for treating barnyard runoff and milk parlour waste. Given the increasing problem of phosphorus (P) pollution in the Lake Champlain region, a slag based P-removal filter technology (PFT) was established (2004) at the CW with two objectives: (i) to test the filters' efficiency as an upgrade unit for improving P removal performance via SSF-CW (ii) to investigate the capacity of filters technology to remove P as a "stand alone" unit. Six individual filters (F1-F6) were filled with electric arc furnace (EAF) steel slag, each containing 112.5 kg of material with a pore volume of 21 L. F1-F4, fed with CW treated water, received approximately 2.17 g DRP kg(-1) EAF steel slag (0.25 kg DRP total) during the 259 day feeding period. F1-F4 retained 1.7 g DRP kg(-1) EAF steel slag, resulting in an average P removal efficiency of 75%. The addition of filters improved CW DRP removal efficiency by 74%. F5 and F6, fed non-treated water, received 1.9 g DRP kg(-1) EAF steel slag (0.22 kg DRP in total) and retained 1.5 g DRP kg(-1) resulting in a P removal efficiency of 72%. The establishment of the EAF slag based PFT is the first in-field evaluation of this technology to reduce P from dairy farm effluent in Vermont.

  12. Evaluation of the emission characteristics of PCDD/Fs from electric arc furnaces.

    Science.gov (United States)

    Chang, Moo Been; Huang, Hung Chi; Tsai, Shian Sheng; Chi, Kai Hsien; Chang-Chien, Guo Ping

    2006-03-01

    Distribution of PCDD/F (polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran) congeners at two electric arc furnaces (EAFs) in Taiwan is evaluated via intensive stack sampling and analysis. Two kinds of exhaust system in EAFs including stack system and shutter system are selected for measuring dioxin emissions. In addition, dioxin emissions during oxidation and reduction stages at EAF-A were characterized. Results indicate that the PCDD/F concentration of stack gas in EAF-A was 4.39 ng/Nm(3) while total Toxic Equivalent Quantity (TEQ) concentration was 0.35 ng I-TEQ/Nm(3). The PCDD/F concentration of stack gas in EAF-B was 2.20 ng/Nm(3) and the TEQ concentration was 0.14 ng I-TEQ/Nm(3). 1,2,3,4,6,7,8-H(p)CDF, OCDD and OCDF are the major contributors of the dioxin concentrations for two EAFs investigated and the percentage of PCDD/F in particulate phase increases as the chlorination level of the PCDD/F congener increases. The results obtained on gas/particulate partitioning of PCDD/Fs in flue gases prior to the APCD in EAFs indicate that more than 90% exists in particulate phase. In EAF-A, the PCDD/F concentration during oxidation stage is slightly higher than that measured during reduction stage, including the sampling points of CO converter outlet, prior to bag filter and stack. Majority of PCDD/Fs emitted from steel-making processes exists in particulate-phase (about 60-70%) at both EAFs investigated.

  13. Electric arc furnaces for steel-making: hot spots for persistent organic pollutants.

    Science.gov (United States)

    Odabasi, Mustafa; Bayram, Abdurrahman; Elbir, Tolga; Seyfioglu, Remzi; Dumanoglu, Yetkin; Bozlaker, Ayse; Demircioglu, Hulusi; Altiok, Hasan; Yatkin, Sinan; Cetin, Banu

    2009-07-15

    Persistent organic pollutant (POP) concentrations were measured in stack-gases of ferrous scrap processing steel plants with electric arc furnaces (EAFs) (n = 5) in Aliaga, Izmir, Turkey and in air (n = 11) at a site near those plants. Measured stack-gas concentrations for the four plants without scrap preheating (611 +/- 311, 165,000 +/- 285,000, and 33 +/- 3 ng m(-3), average +/- SD for sigma41PCBs, sigma16PAHs, and sigma7PBDEs, respectively) indicated that they are significant sources for polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). POP emissions from the plant with scrap preheating were significantly higher (13 500, 445 000, and 91 ng m(-3) for sigma41PCBs, sigma16PAHs, and sigma7PBDEs, respectively). It was also shown that the steel plants emit considerable amounts of fugitive POPs in particle-phase. Estimated emissions using the emission factors generated in this study and the production amounts suggested that the steel plants with EAFs may significantly contribute to local and global PAH, PCB, and PBDE emissions. Several other compounds (aromatic and aliphatic hydrocarbons, oxygen, sulfur, nitrogen, and chlorine-containing organic compounds, n = 49) were identified and determined semiquantitatively in the stack-gas and ambient air samples. Ambient air concentrations (62 +/- 35, 320 +/- 134 ng m(-3), 1451 +/- 954 pg m(-3), for sigma41PCBs, sigma16PAHs, and sigma7PBDEs, respectively) were significantly higher than those measured previously around the world and in the region, further confirming that the steel plants with EAFs are "hot spots" for POPs.

  14. [Phosphorus adsorption and regeneration of electric arc furnace steel slag as wetland medium].

    Science.gov (United States)

    Zhai, Li-hua; He, Lian-sheng; Xi, Bei-dou; Chen, Yue; Meng, Rui; Huo, Shou-liang; Liu, Hong-liang

    2008-12-01

    The long-term phosphorus (P) adsorption and retention capacities of electric arc furnace (EAF) steel slag materials derived from one batch and a 278-d column experiments with a synthetic P solution were compared. The investigations of the regeneration of the P adsorption capacity by water level decrease was conducted. It was revealed column experiment on a long-term basis can determine P saturation of EAF accurately. And the results can be used for realistic estimations of constructed wetland systems (CWS) longevity. EAF slag showed a high afinity for P, reaching a saturation value of 1.65 g/kg. Regeneration experiment of the P adsorbing capacity by this material showed that, after 4 weeks of water level decrease, EAF steel slag was able to increase its initial P adsorption capacity to 2.65 g/kg. A sequential P fractionation experiment was performed to quantify the proportion of P bound to mineral compounds in EAF. From the most loosely bound to the most strongly bound P fraction, P1 was associated with resin extractable (13%), Fe extractable (0.5 mol/L Na2CO3, 39%), Al extractable (0.1 mol/L NaOH, 21%), Ca extractable (1 mol/L HCl, 13%), and Ca in a stable residual pool (concentrated hot HCl, 14%). X-ray fluorescence analyses of EAF steel slag chemical composition revealed that the continuous application of a P solution resulted in 300% and 170% increases in K2O and P2O5, respectively. Al2O3 and FeO increased by 8%, while the portion of CaO remained unchanged. The investigated properties (P retention potential, regeneration of P adsorption, P fractionation) provide useful data about the suitability of slag material as a media for longterm P removal and dry-wet operation can improve P retention capacity of EAF to prolong the longevity of full-scale CWS.

  15. Solidification/stabilisation of electric arc furnace waste using low grade MgO.

    Science.gov (United States)

    Cubukcuoglu, B; Ouki, S K

    2012-02-01

    This study aims to evaluate the potential of low grade MgO (LGMgO) for the stabilisation/solidification (S/S) of heavy metals in steel electric arc furnace wastes. Relevant characteristics such as setting time, unconfined compressive strength (UCS) and leaching behaviour assessed by acid neutralisation capacity (ANC), monolithic and granular leaching tests were examined in light of the UK landfill Waste Acceptance Criteria (WAC) for disposal. The results demonstrated that all studied mix designs with Portland cement type 1 (CEM1) and LGMgO, CEM1-LGMgO 1:2 and 1:4 at 40% and 70% waste addition met the WAC requirements by means of UCS, initial and final setting times and consistence. Most of the ANC results met the WAC limits where the threshold pH values without acid additions were stable and between 11.9 and 12.2 at 28d. Granular leaching results indicate fixation of most of the metals at all mix ratios. An optimum ratio was obtained at CEM1-LGMgO 1:4 at 40% waste additions where none of the metals leaching exceeded the WAC limits and hence may be considered for landfill disposal. The monolithic leaching test results showed that LGMgO performed satisfactorily with respect to S/S of Zn, as the metal component present at the highest concentration level in the waste exhibited very little leaching and passed the leaching test requirement at all mix ratios studied. However, its performance with respect to Pb, Cd and Cr was less effective in reducing their leaching suggesting a higher cumulative rate under those leaching regimes.

  16. Identification and characterization of the atmospheric emission of polychlorinated naphthalenes from electric arc furnaces.

    Science.gov (United States)

    Liu, Guorui; Zheng, Minghui; Du, Bing; Nie, Zhiqiang; Zhang, Bing; Hu, Jicheng; Xiao, Ke

    2012-09-01

    Electric arc furnaces (EAF) are well recognized as significant sources of dioxins. EAFs have also been speculated to be sources of polychlorinated naphthalenes (PCNs) due to the close correlation between dioxin and PCN formation. However, assessment on PCN emissions from EAFs has not been carried out. The primary aim of this preliminary study is to identify and characterize the atmospheric emission of PCNs from EAFs. In this preliminary study, stack gas samples from two typical EAFs with different scales (EAF-1, 160 t batch(-1); and EAF-2, 60 t batch(-1)) were collected by automatic isokinetic sampling technique, and PCN congeners in samples were analyzed by isotope dilution high-resolution gas chromatography combined with high-resolution mass spectrometry method. Emission concentrations of PCNs were 458 and 1,099 ng m(-3) for EAF-1 and EAF-2, respectively. The emission factors of PCNs to air were 21.6 and 30.1 ng toxic equivalent t(-1) for EAF-1 and EAF-2, respectively, which suggested that EAF is an important source of PCN release. With regard to the characteristics of PCNs from EAFs, lower chlorinated homologues were dominant. The PCN congeners comprised of CN27/30, CN52/60, CN66/67, and CN73 were the most abundant congeners for tetra-, penta-, hexa-, and hepta-chlorinated homologues, respectively. EAFs were identified to be an important PCN source, and the obtained data are useful for developing a PCN inventory. The congener profiles of PCNs presented here might provide helpful information for identifying the specific sources of PCNs emitted from EAFs.

  17. Long and short-term performance of a stabilized/solidified electric arc furnace dust.

    Science.gov (United States)

    Pereira, C Fernández; Galiano, Y Luna; Rodríguez-Piñero, M A; Parapar, J Vale

    2007-09-30

    The application of class F fly ash, cement and lime to the Stabilization/Solidification (S/S) of electric arc furnace dust containing hazardous metals such as Zn, Pb, Cd, and Cr is described. The aim of the study was to determine the influence of the setting conditions during the S/S treatment and to know the behaviour of an aged solidified and stabilized waste. In order to determine the efficiency attained by the S/S process, USEPA TCLP, and other leaching tests have been accomplished. In addition, the compressive strength of the solidified waste at different times has been determined. In order to study the influence of the environmental conditions in which setting occurs, experiments were carried out with samples of the same composition, under different setting conditions: laboratory environment, stove at a temperature of 40-60 degrees C and setting in a hermetically sealed plastic bag at room temperature. All the samples were subjected to the TCLP test at 28 days, and the metal content of the resulting leachates was analysed. The results show that in some cases the setting conditions of the mixtures have a noticeable influence on the characteristics of the leachate. The evolution with time of some S/S solids, one month after their manufacture and more than 9 years after that has also been evaluated, by means of their leaching behaviour. The results obtained in this work have shown, in all the laboratory cured samples that the leachate pH decrease in the course of time, and consequently the leaching behaviour is in general worse. This could be due to the carbonation of the S/S solid and the subsequent loss of alkalinity.

  18. Polychlorinated naphthalene (PCN) emissions from scrap processing steel plants with electric-arc furnaces.

    Science.gov (United States)

    Odabasi, Mustafa; Dumanoglu, Yetkin; Kara, Melik; Altiok, Hasan; Elbir, Tolga; Bayram, Abdurrahman

    2017-01-01

    Polychlorinated naphthalene (PCN) emissions of scrap iron processing steel plants were explored by measuring concentrations in stack gases of five plants, in the atmosphere (n=11) at a site close to those plants, and in soil at several sites in the region (n=40) in Aliaga, Izmir, Turkey. Observed stack-gas Σ32PCN levels from the plants without scrap preheating (189±157ngNm(-3), average±SD, n=4) showed that they are substantial PCN emitting sources. Stack-gas Σ32PCN level for the plant with scrap preheating was considerably higher (1262ngNm(-3)). Similarly, Σ32PCN emission factor for this plant was substantially higher (11.9mgton(-1)) compared to those without scrap preheating (1.30±0.98mgton(-1)). Results have also suggested that the investigated steel plants emit large quantities of fugitive particle-phase PCNs. Measured soil Σ32PCN concentrations that are considered to be representative of the atmospheric levels were greatly variable in the region, ranging between 0.003 and 10.02μgkg(-1) (dry wt). Their spatial distribution showed that main PCN sources in the region were the iron-steel plants. Ambient air levels (1620±800pgm(-3)) were substantially higher than ones observed around the world and in the study area verifying that the steel plants with electric arc furnaces (EAFs) are important PCN sources. Investigation of possible mechanisms suggested that the combustion processes also contribute to emissions from EAFs in addition to evaporation of PCNs present in the scrap iron.

  19. In vitro assessment of genotoxic effects of electric arc furnace dust on human lymphocytes using the alkaline comet assay.

    Science.gov (United States)

    Garaj-Vrhovac, Vera; Orescanin, Visnja; Ruk, Damir; Gajski, Goran

    2009-02-15

    In vitro genotoxic effects of leachates of electric arc furnace dust (EAFD) on human peripheral lymphocytes, assessed prior and following the treatment with a strong alkaline solution were investigated using the alkaline comet assay. Prior and following the treatment, lymphocytes were incubated with leachate of EAFD for 6 and 24 hours at 37 degrees C. Negative controls were also included. Mean values of the tail lengths established in the samples treated with the leachate stemming from the original dust for 6 and 24 hours, were 15.70 microm and 16.78 microm, respectively, as compared to 12.33 microm found in the control sample. Slight, but significant increase in the tail length was also found with the dust treated with a strong alkaline solution (13.37 microm and 13.60 microm). In case of high heavy metal concentrations (the extract of the original furnace dust), the incubation period was revealed to be of significance as well. The obtained results lead to the conclusion that alkaline comet assay could be used as a rapid, sensitive and low-cost tool when assessing genotoxicity of various waste materials, such as leachates of the electric arc furnace dust.

  20. Effect of oxyfuel burner ratio changes on energy efficiency in electric arc furnace at Co-Steel Lasco

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, M.J. [University of Toronto (Canada). Dept. of Mechanical and Industrial Engineering; Kournetas, N.G.; Sommerville, I.D.; McLean, A. [University of Toronto (Canada). Dept. of Metallurgy and Materials Science; Evenson, E. [Stantec Global Technologies Ltd., Mississauga (Canada); Guerard, J. [Co-Steel Lasco, Whitby (Canada)

    2001-07-01

    Trials were conducted on Co-Steel Lasco's electric arc furnace (EAF) to evaluate the effect of oxyfuel burner ratio changes on furnace energy efficiency and productivity. Carefully controlled trials with the collection of numerous process and sample data over 331 heats provided statistically significant results. The oxygen available for post-combustion in the furnace was increased by 19%. As the burners were operating at their maximum oxygen constraint, this was achieved by decreasing the natural gas consumption by 43%. Results of this study indicate that decreases in terms of specific electrical energy consumption (4.0%), power on time (5.0%), and tap to tap time (4.5%) were realised. Slag chemistry, electrode consumption, and yield were not affected. Measurement data support the finding that more heat was transferred into the steel with the post-combustion burners: a flat bath was achieved earlier; high bath temperatures were reached more quickly; power on time was reduced, leading to reduced electrical energy consumption. Analysis suggests that furnace thermal energy losses were reduced by less air inleakage, less incomplete methane combustion, and earlier achievement of foamy slag conditions. (author)

  1. Usage of Thermodynamic Activity for Optimization of Power Expenses in Respect of Casting Process in Arc Steel-Melting Furnace

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The equilibrium between carbon and oxygen has been investigated during oxidizing refining in an arc steel-melting furnace. It is shown that there is a possibility to apply an equilibrium thermodynamic. It has been established that during oxidizing refining FeO concentration in slag practically does not depend on C concentration in metal. It is demonstrated that in a number of cases metal carbon oxidation is characterized by the presence of a transit period that may be attributed to incomplete slag-formation process.

  2. Recycling of Malaysia's electric arc furnace (EAF) slag waste into heavy-duty green ceramic tile.

    Science.gov (United States)

    Teo, Pao-Ter; Anasyida, Abu Seman; Basu, Projjal; Nurulakmal, Mohd Sharif

    2014-12-01

    Recently, various solid wastes from industry such as glass waste, fly ash, sewage sludge and slag have been recycled into various value-added products such as ceramic tile. The conventional solutions of dumping the wastes in landfills or incineration, including in Malaysia are getting obsolete as the annual huge amount of the solid wastes would boost-up disposal cost and may cause permanent damage to the flora and fauna. This recent waste recycling approach is much better and greener as it can resolve problems associated with over-limit storage of industrial wastes and reduce exploration of natural resources for ceramic tile to continuously sustain the nature. Therefore, in this project, an attempt was made to recycle electric arc furnace (EAF) slag waste, obtained from Malaysia's steel making industry, into ceramic tile via conventional powder compaction method. The research work was divided into two stages. The first stage was to evaluate the suitability of EAF slag in ceramic tile by varying weight percentage of EAF slag (40 wt.%, 50 wt.% and 60 wt.%) and ball clay (40 wt.%, 50 wt.% and 60 wt.%), with no addition of silica and potash feldspar. In the second stage, the weight percentage of EAF slag was fixed at 40 wt.% and the percentage of ball clay (30 wt.% and 40 wt.%), feldspar (10 wt.% and 20 wt.%) and silica (10 wt.% and 20 wt.%) added was varied accordingly. Results obtained show that as weight percentage of EAF slag increased up to 60 wt.%, the percentage of apparent porosity and water absorption also rose, with a reduction in tile flexural strength and increased porosity. On the other hand, limiting the weight percentage of EAF slag to 40 wt.% while increasing the weight percentage of ball clay led to a higher total percentage of anorthite and wollastonite minerals, resulting in higher flexural strength. It was found that introduction of silica and feldspar further improved the flexural strength due to optimization of densification process. The highest

  3. Investigations on phosphorus recovery and reuse as soil amendment from electric arc furnace slag filters.

    Science.gov (United States)

    Bird, Simon C; Drizo, Aleksandra

    2009-11-01

    Electric arc furnace (EAF) steel slag has been identified as an effective filter material for the removal of phosphorus (P) from both point and non-point sources. To determine the feasibility of land-applying P saturated EAF steel slag this study was undertaken to investigate (i) saturated EAF steel slag material's potential as a P fertilizer or soil amendment and (ii) P desorption and metals leachate from saturated EAF steel slag material to surface runoff. Medicago sativa (alfalfa) was planted in a nutrient depleted washed sand media. Phosphorus was added either as saturated EAF steel slag or as a standard commercial phosphate fertilizer in order to assess the plant availability of the P from saturated EAF steel slag. Four different P application levels were tested: a low (20 lbs acre furrow slice(-1) (5.5 g P m(-3))) two medium (40 and 60 lbs. acre f.s.(-1) (11 and 16.5 g P m(-3))) and a high (120 lbs. acre f.s.(-1) (33 g P m(-3))). The above-ground biomass of half of the plants was harvested after 5 weeks and the second half at 10 weeks. All treatments regardless of the P source used showed high rates of germination. At the first harvest period (5 weeks) significantly higher above-ground biomass (p < 0.01) was seen at the 3 highest P amendment rates in treatments with triple super phosphate fertilizer (TSP) than with EAF steel slag. However, by the second harvest (10 weeks) only the highest amendment rate of TSP showed a significantly higher amount of biomass (p < 0.01), suggesting that EAF steel slag might be an effective slow release P source. In a second experiment, a rain simulator was used to assess desorption of DRP, TP and metals from a saturated and semi-saturated EAF steel slag. The results revealed that the total amounts of DRP and TP released to surface runoff from EAF steel slag were negligible when compared to the total quantities of P retained by this material. Overall the results from this study demonstrated that once the EAF steel slag filter

  4. Study of the instability of black slags from electric arc furnace steel industry

    Directory of Open Access Journals (Sweden)

    Frías, M.

    2002-09-01

    Full Text Available In Spain, the steel manufacture produces important quantities of by-products, representing between 15 and 20 % of total steel production. Most by-products are deposited on open air spaces causing serious economical and environmental problems, internationally, different recycling wais are studied, being the main alternative for these by-products as recycled aggregate. The possibility of recycling these by-products in construction sector depends on its possible volume instability because of the presence of some undesirable compounds. In current paper, two different black slags from electric arc furnace steel industry were chemically characterized, paying attention to some well-known compounds by theirs expansion effects, such as: free CaO, free MgO, chlorides and sulphates. The analytical results carried out in the current research detected the presence of insignificant or null amounts of harmful compounds. Therefore, they should not have any negative incidence on phenomena of volume instability.

    En España la fabricación de acero produce grandes cantidades de residuos industriales, las cuales representan entre el 15-20 % de la producción total de acero, en su mayor parte se depositan en vertederos, causando serios problemas económicos y medioambientales a todos los sectores implicados. A nivel internacional, se están estudiando diferentes vías de reutilización, siendo su uso principal como árido de reciclado. La posibilidad de reutilizar estos subproductos industriales en el sector de la construcción se basa en su posible inestabilidad volumétrica, debido a la presencia de ciertos compuestos no deseados. En este trabajo se caracterizan químicamente 2 escorias negras de horno de arco eléctrico con diferente procedencia y se cuantifican algunos de los principales compuestos conocidos por sus efectos expansivos, como: cal libre, magnesia libre, cloruros y sulfatos. Los resultados analíticos de estas dos escorias negras muestran

  5. Physics-Based Modeling of Electric Operation, Heat Transfer, and Scrap Melting in an AC Electric Arc Furnace

    Science.gov (United States)

    Opitz, Florian; Treffinger, Peter

    2016-04-01

    Electric arc furnaces (EAF) are complex industrial plants whose actual behavior depends upon numerous factors. Due to its energy intensive operation, the EAF process has always been subject to optimization efforts. For these reasons, several models have been proposed in literature to analyze and predict different modes of operation. Most of these models focused on the processes inside the vessel itself. The present paper introduces a dynamic, physics-based model of a complete EAF plant which consists of the four subsystems vessel, electric system, electrode regulation, and off-gas system. Furthermore the solid phase is not treated to be homogenous but a simple spatial discretization is employed. Hence it is possible to simulate the energy input by electric arcs and fossil fuel burners depending on the state of the melting progress. The model is implemented in object-oriented, equation-based language Modelica. The simulation results are compared to literature data.

  6. Investigation of possibility for stabilization and valorization of electric ARC furnace dust and glass from electronic waste

    Directory of Open Access Journals (Sweden)

    Ranitović M.

    2014-01-01

    Full Text Available This paper presents investigation of possibility for electric arc furnace dust (EAFD and electronic waste (e-waste valorization trough stabilization process, in order to achieve concurrent management of these two serious ecological problems. EAFD is an ineviTab. waste material coming from the electric arc furnace steel production process, classified as a hazardous waste. Furthermore, it is well known that residual materials generated in the ewaste recycling process, like LCD (Liquid crystal displays waste glass, are not suiTab. for landfill or incineration. In this study, these two materials were used for investigation of possibility for their valorization in ceramic industry. Thus, an innovative synergy of waste streams from metallurgical and e-waste recycling industry is presented. Investigation included a complex characterization of raw materials and their mixtures, using chemical methods, optical microscopy, scanning electron microscopy, as well as methods for determining the physical and mechanical properties. Based on these results, it was found that material suiTab. for use in ceramics industry as a partial substituent of quartzite and fluxing components can be produced. Besides solving the environmental problem related to EAFD and LCD disposal, by replacement of raw materials certain economic effects can be achieved. [Projekat Ministarstva nauke Republike Srbije, br. 34033

  7. Effect of Feed Forms on the Results of Melting of Fly Ash by a DC Plasma Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    CHEN Mingzhou; MENG Yuedong; SHI Jiabiao; NI Guohua; JIANG Yiman; YU Xinyao; ZHAO Peng

    2009-01-01

    Fly ash from a municipal solid waste incinerator (MSWI) without preprocessing (original fly ash,OFA) was melted by a direct current (DC) plasma arc furnace to investigate how the feed forms governed the results.Dioxins in flue gas from stack and bag-filter ash (BFA) were detected.The distribution of heavy metals of Pb,Cd,As,and Cr along the flue gas process system was analyzed.Through a comparison of the results for dioxins and heavy metals in this study and previous work,carrying-over of fly ash particles with the flue gas stream can be deduced.Based on the magnetic induction equation and Navier-Stokes equations,a magnetohydrodynamic (MHD) model for the plasma arc was developed to describe the particle-carrying effect.The results indicate that,a.when melted,the feed forms of MSWI fly ash affect the results significantly;b.it is not preferable to melt MSWI fly ash directly,and efforts should be made to limit the mass transfer of OFA from the plasma furnace.

  8. Improvement of refractories for bottom of DC-Arc furnace; Chokuryudenkiro no roshoyo taikabutsu no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kawahara, Toshihiro; Suzuki, Koichi; Okamoto, Yutaka; Tokuchi, Kazumasa [Asahi Glass Corp., Tokyo (Japan)

    1999-06-01

    A conductive refractory furnace bottom type DC electric furnace has disadvantages of large material cost, large working cost and long working period in refractory replacement due to a large amount of refractory installation. The furnace bottom has three layers of permanent bricks, wear bricks and a hot repair material, and durability improvement of wear bricks is an important issue. From the study results for 4 years in a real furnace the following conclusions were obtained: (1) The use of MgO-C based unburned bricks of 15% carbon content as wear bricks reduced the erosion speed by about 20% compared with a conventional MgO-C based burned bricks of 20% carbon content, (2) The resistivity value of the MgO-C based unburned brick decreased to a value equivalent to that of MgO-C based burned brick, which gave no problem in electro conductivity, (3) The addition of the hot repair material over 260 degree C of furnace bottom temperature and stable forming of a protective coating layer of 200-400 mm thickness enabled high durability over 6,400 heats of wear bricks, and (4) The use of the permanent bricks for 15,477 heats promised possible further use. (NEDO)

  9. Where Diffusion of Clean Technologies and Barriers to Innovation Clash: Application to the Global Diffusion of the Electrical Arc Furnace

    Directory of Open Access Journals (Sweden)

    José Antonio Moya

    2017-01-01

    Full Text Available This paper analyses the role of barriers preventing the worldwide take-up of a clean technology: the electrical arc furnace. It also identifies which barriers affect a parameter that summarises the combined effect of all of them. The first step, determination of the combined effect of the barriers, is carried out using a novel approach to model the diffusion of innovations. This new approach is composed only by terms that account for the driver of innovations and the parameter that summarises the effect of barriers. The objective quantification of the effect of barriers in the diffusion of innovations opens up new opportunities for designing policies to overcome the barriers identified as the most relevant, for identifying the effect of existing policies, for relating innovation indicators with those barriers or for better incorporating the effect of barriers in bottom-up models that forecast the technological evolution of the economy.

  10. Characterization of electric arc furnace dust aiming reuse; Caracterizacao da poeira de aciaria eletrica visando o seu reaproveitamento

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, F.F.; Oliveira, E.B.G.; Oliveira, J.R. de, E-mail: fgrillo@ifes.edu.b [Instituto Federal de Ciencia e Tecnologia do Espirito Santo (IFES), Vitoria, ES (Brazil); Telles, V.B.; Tenorio, J.A.S. [Universidade de Sao Paulo (USP), SP (Brazil)

    2010-07-01

    This work aims to study the characterize of steelmaking dust, from the primary refining of steel in Electric Arc Furnace, in order to verify feasibility of reuse through the addition of hot metal in the form of briquette. The techniques used to characterize the dust was chemical analyses, size separation tests, X-ray diffraction analyses (XRD), Scanning Electron Microscopy (SEM). After characterization, was the calculation of reductant considering the complete reduction of iron oxides and then to briquetting. The waste sample is composed essentially of spherical particles and has a very small particle size (85% below 10 {mu}m). The XRD has presented compounds such as ZnFe{sub 2}O{sub 4}, Fe{sub 3}O{sub 4}, ZnO e SiO{sub 2}. This work showed that its possible recovery approximately 92% of metal iron from dust generated during steelmaking.This (author)

  11. Experimental evaluation of high performance base course and road base asphalt concrete with electric arc furnace steel slags.

    Science.gov (United States)

    Pasetto, Marco; Baldo, Nicola

    2010-09-15

    The paper presents the results of a laboratory study aimed at verifying the use of two types of electric arc furnace (EAF) steel slags as substitutes for natural aggregates, in the composition of base course and road base asphalt concrete (BBAC) for flexible pavements. The trial was composed of a preliminary study of the chemical, physical, mechanical and leaching properties of the EAF steel slags, followed by the mix design and performance characterization of the bituminous mixes, through gyratory compaction tests, permanent deformation tests, stiffness modulus tests at various temperatures, fatigue tests and indirect tensile strength tests. All the mixtures with EAF slags presented better mechanical characteristics than those of the corresponding asphalts with natural aggregate and satisfied the requisites for acceptance in the Italian road sector technical standards, thus resulting as suitable for use in road construction.

  12. Innovative Concept for the Recovery of Silver and Indium by a Combined Treatment of Jarosite and Electric Arc Furnace Dust

    Science.gov (United States)

    Wegscheider, S.; Steinlechner, S.; Leuchtenmüller, M.

    2016-11-01

    Industrial wastes such as slags, dust, or precipitation residues contain significant amounts of valuable metals like zinc, lead, and copper as well as precious metals like silver and indium. Nevertheless, a lot of these waste materials are not recycled, and therefore, many valuable metals end up being sent to landfills. Because of harmful components in the waste, it is often necessary to send it to specialized landfills for hazardous wastes, which leads to environmental problems as well as additional costs. Consequently, the recovery of the valuable metals from the residues represents a sensible task to decrease the negative impact on the environment and to reduce costs for maintaining a landfill. In addition, recycling helps to decrease the dependency from primary resources. The present study deals with the behavior of different metals in a pyro-metallurgical treatment for a mixture of jarosite and electric arc furnace dust with a special focus on indium and silver.

  13. The influence of the structure of the metal load removal from liquid steel in electric arc furnaces

    Science.gov (United States)

    Pǎcurar, Cristina; Hepuť, Teodor; Crisan, Eugen

    2016-06-01

    One of the main technical and economic indicators in the steel industry and steel respectively the development it is the removal of liquid steel. This indicator depends on several factors, namely technology: the structure and the quality metal load, the degree of preparedness of it, and the content of non-metallic material accompanying the unit of drawing up, the technology for the elaboration, etc. research has been taken into account in drawing up steel electric arc furnace type spring EBT (Electric Bottom taping), seeking to load and removing components of liquid steel. Metal load has been composed of eight metal grades, in some cases with great differences in terms of quality. Data obtained were processed in the EXCEL spreadsheet programs and MATLAB, the results obtained being presented both graphically and analytically. On the basis of the results obtained may opt for a load optimal structure metal.

  14. Development of Long Life Magnesia—carbon Brick for UHP Electric Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    SUNYufei; WANGXuemei

    2000-01-01

    The corrosion mechanism of high ferric oxide slag to the magnesia-carbon brick for UHP furnace was analyzed,and the magnesia-carbon brick with high ferric oxide slag resistance was develped by selecting specially processed fused magnesite and changing size distrbution and the additives.The magnesia-carbon brick has good affinity to the slag and could adhere the slag efficiently in usage,It has better slag corrosion resistance and high temperature strength than the ordinary magnesia-carbon brick It showed better adaptable to the high ferric oxide slag when it was first used in 1999 in 150t UHP furnace of Tianjing Steel Pipe Company ,and achieved 400 heats service life.

  15. A two-stage metal valorisation process from electric arc furnace dust (EAFD

    Directory of Open Access Journals (Sweden)

    H. Issa

    2016-04-01

    Full Text Available This paper demonstrates possibility of separate zinc and lead recovery from coal composite pellets, composed of EAFD with other synergetic iron-bearing wastes and by-products (mill scale, pyrite-cinder, magnetite concentrate, through a two-stage process. The results show that in the first, low temp erature stage performed in electro-resistant furnace, removal of lead is enabled due to presence of chlorides in the system. In the second stage, performed at higher temperatures in Direct Current (DC plasma furnace, valorisation of zinc is conducted. Using this process, several final products were obtained, including a higher purity zinc oxide, which, by its properties, corresponds washed Waelz oxide.

  16. The oxidation and reduction of chromium of stainless steels in an eletric arc furnace

    Directory of Open Access Journals (Sweden)

    B. Arh

    2011-07-01

    Full Text Available The oxidation of chromium during the elaboration of stainless steels occurs with oxygen in solution blown inthe melt and with oxides in the slag. A higher content of silicon in the furnace charge decreases the extent of oxidation of chromium, however, the efficient reduction of chromium from the slag is of essential importance for a minimal loss of chromium. In this survey, the theory of the oxidation of chromium, its reduction from the slag and the conditions for the formation of foaming slag are discussed.

  17. Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans from stack gases of electric arc furnaces and secondary aluminum smelters.

    Science.gov (United States)

    Lee, Wei-Shan; Chang-Chien, Guo-Ping; Wang, Lin-Chi; Lee, Wen-Jhy; Wu, Kuen-Yuh; Tsai, Perng-Jy

    2005-02-01

    This study investigates the emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from four electric arc furnaces (EAFs) and eight secondary aluminum smelters (secondary ALSs) in Taiwan. The mean PCDD/F International-Toxicity Equivalents (I-TEQ) concentrations in the stack gases of these EAFs and secondary ALSs are 0.28 ng I-TEQ/Nm3 (relative standard deviation [RSD]= 100%) and 3.3 ng I-TEQ/Nm3 (RSD = 260%), respectively. The high RSDs, especially for those obtained from secondary ALSs, could be caused by the intrinsic differences in their involved feeding materials, furnace operating conditions, and air pollution control devices. The mean I-TEQ emission factor of PCDD/Fs for EAFs (1.8 microg I-TEQ/tonne-feedstock) is lower than that for secondary ALSs (37 microg I-TEQ/tonne-feedstock). This result might be because the involved furnace temperatures for secondary ALSs (650-750 degrees C) are lower than those for EAFs (1600-1700 degrees C), resulting in the deterioration of the combustion condition, leading to the formation of PCDD/Fs during the industrial process. This study found that the total PCDD/F emissions from EAFs (20 g I-TEQ/yr) and secondary ALSs (18 g I-TEQ/yr) are approximately 27, 53, and approximately 24, 49 times higher than those from municipal solid waste incinerators (MSWIs; 0.74 g I-TEQ/yr) and medical waste incinerators (MWIs; 0.37 g I-TEQ/yr), respectively; while those are 44 and 40% of total PCDD/F emission from sinter plants (45 g I-TEQ/ yr), respectively. Considering a more stringent emission limit has been applied to waste incinerators (0.1 ng I-TEQ/Nm3) in Taiwan lately, the results suggest that the control of the emissions from metallurgical processes has become the most important issue for reducing the total PCDD/F emission from industrial sectors to the ambient environment.

  18. Electric arc furnace dust utilization in iron ore sintering: influence of particle size; Utilizacao da poeira de aciaria eletrica na sinterizacao de minerio de ferro: influencia da granulometria

    Energy Technology Data Exchange (ETDEWEB)

    Telles, V.B.; Junca, E.; Rodrigues, G.F.; Espinosa, D.C.R.; Tenorio, J.A.S., E-mail: victor_bridit@hotmail.co [Universidade de Sao Paulo (USP), SP (Brazil). Dept. de Engenharia Metalurgica e de Materiais

    2010-07-01

    The aim of this work was to study the utilization of electric arc furnace dust (EAFD) generated in steelmaking by electric arc furnace (EAF) as raw material in iron ore sintering. The waste was characterized by size, chemical composition and X-ray diffraction. The physical characterization showed that 90% of the particles have a size less then 1,78 {mu}m and the material have the tendency to agglomerate. The waste were submitted to a pre-agglomeration prior to its incorporation in the sinter. The influence on the addition of the waste with different granulometry in the iron or sinter production were analyzed by sinter characterization and sintering parameters. (author)

  19. Destruction of inorganic municipal solid waste incinerator fly ash in a DC arc plasma furnace.

    Science.gov (United States)

    Zhao, Peng; Ni, Guohua; Jiang, Yiman; Chen, Longwei; Chen, Mingzhou; Meng, Yuedong

    2010-09-15

    Due to the toxicity of dioxins, furans and heavy metals, there is a growing environmental concern on municipal solid waste incinerator (MSWI) fly ash in China. The purpose of this study is directed towards the volume-reduction of fly ash without any additive by thermal plasma and recycling of vitrified slag. This process uses extremely high-temperature in an oxygen-starved environment to completely decompose complex waste into very simple molecules. For developing the proper plasma processes to treat MSWI fly ash, a new crucible-type plasma furnace was built. The melting process metamorphosed fly ash to granulated slag that was less than 1/3 of the volume of the fly ash, and about 64% of the weight of the fly ash. The safety of the vitrified slag was tested. The properties of the slag were affected by the differences in the cooling methods. Water-cooled and composite-cooled slag showed more excellent resistance against the leaching of heavy metals and can be utilized as building material without toxicity problems.

  20. Hazard Analysis of Submerged Arc Furnace Shell Installation%矿热炉炉壳安装作业危险性分析

    Institute of Scientific and Technical Information of China (English)

    窦强; 程玉龙

    2015-01-01

    为减少事故损失,必须对矿热炉安装施工危险源进行分析。基于此,对矿热炉安装工序中最重要工序炉壳安装应用作业危险性分析进行分析。将炉壳安装作业分成3大部分,用鱼刺图分析方法进行分析,总结出矿热炉炉壳安装中事故发生的主要原因并提出对策措施,以预防和减少事故的发生。%In order to reduce the loss of accidents ,hazard analysis of submerged arc furnace installation is very necessary . Based on this ,this paper conducts hazard analysis on the important process ,submerged arc furnace shell installation .The analysis is divided into 3 parts and the fishbone diagram is applied .It is summarized the main causes of accidents in the in-stallation of submerged arc furnace shell and also some corresponding measures are raised ,to prevent and reduce the acci-dents .

  1. Aluminum Bronze Alloys to Improve the System Life of Basic Oxygen and Electric Arc Furnace Hoods, Roofs and Side Vents.

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence C. Boyd Jr.; Dr. Vinod K. Sikka

    2006-12-29

    Energy Industries of Ohio was the lead organization for a consortium that examined the current situation involving the service life of electric arc and basic oxygen furnace hoods, roofs and side vents. Republic Engineered Products (REP), one of the project partners, installed a full-scale Al-Bronze “skirt” in their BOF at their Lorain OH facility, believed to be the first such installation of this alloy in this service. In 24 months of operation, the Al-Bronze skirt has processed a total of 4,563 heats, requiring only 2 shutdowns for maintenance, both related to physical damage to the skirt from operational mishaps. Yearly energy savings related to the REP facility are projected to be ~ 10 billion Btu's with significant additional environmental and productivity benefits. In recognition of the excellent results, this project was selected as the winner of the Ohio’s 2006 Governor’s Award for Excellence in Energy, the state’s award for outstanding achievements in energy efficiency.

  2. A Fundamental Wave Amplitude Prediction Algorithm Based on Fuzzy Neural Network for Harmonic Elimination of Electric Arc Furnace Current

    Directory of Open Access Journals (Sweden)

    Wanjun Lei

    2015-01-01

    Full Text Available Electric arc furnace (EAF causes the harmonics to impact on the supply network greatly and harmonic elimination is a very important research work for the power quality associated with EAF. In the paper, a fundamental wave amplitude prediction algorithm based on fuzzy neural network for harmonic elimination of EAF current is proposed. The proposed algorithm uses the learning ability of the neural network to refine Takagi-Sugeno type fuzzy rules and the inputs are the average of the current measured value in different time intervals. To verify the effectiveness of the proposed algorithm, some experiments are performed to compare the proposed algorithm with the back-propagation neural networks, and the field data collected at an EAF are used in the experiments. Moreover, the measured amplitudes of fundamental waves of field data are obtained by the sliding-window-based discrete Fourier transform on the field data. The experiments results show that the proposed algorithm has higher precision. The real curves also verify that the amplitude of fundamental wave current could be predicted accurately and the harmonic elimination of EAF would be realized based on the proposed algorithm.

  3. A fault analysis of DC electric arc furnaces with SVC harmonic filters in a mini-mill plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, Byungju [PQ TECH INC., Youngtong-dong, Youngtong-gu, Suwon 443-813 (Korea); Lee, Hansang; Jang, Gilsoo [School of Electrical Engineering, Korea University, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-701 (Korea); Han, Byungmoon [Department of Electrical Engineering, Myongji University, Nam-dong, Yongin, Gyeonggi-do, 449-728 (Korea)

    2010-07-15

    This paper proposes the most feasible solution to overcome the failure of the 2nd harmonic filter in the static VAR compensator (SVC) which operates with the DC electric arc furnace (EAF) at Gwangyang Steel Mill in Korea. In order to investigate the causes of this failure, various measurements were carried out on the DC EAF and the main transformer at the PCC (point of common connection). It was concluded that the two causes for the failure are; the inrush current in the main transformer, and the parallel resonance between the system impedance and the harmonic filter. Three solutions to suppress the transformer inrush current and another three solutions to avoid the parallel resonance are suggested. The feasibility of these solutions was verified through the computer simulation with PSCAD/EMTDC. The most feasible solution to avoid further failures of the 2nd harmonic filter was selected, based on the estimated result for the six optional solutions in the point of performance and cost. (author)

  4. Formation of hexachlorobenzene from dusts of an electric arc furnace used in steelmaking: effect of temperature and dust composition.

    Science.gov (United States)

    Murakami, Taichi; Shimura, Mizuki; Kasai, Eiki

    2008-10-01

    A certain amount of hexachlorobenzene (HCB), designated a persistent organic pollutant (POP) by the Stockholm Convention, is emitted from an electric arc furnace (EAF) used in the steelmaking process. To understand the formation and decomposition behaviors of HCB during the treatment of waste gases from an EAF, characterization of dust samples from EAFs in different plants was conducted. Dusts 1 and 2 were bag filter dusts collected from a common steel plant and a special steel plant, respectively. The initial concentrations of HCB in dusts 1 and 2 were 62 and < 0.1 ng/g of dust, respectively. Then a series of heating experiments was carried out with these dust samples under various conditions. The formation of HCB from both dusts was not significant under an Ar atmosphere, although the amount of formation from dust 1 slightly increased with an increase in the holding temperature. Under an Ar--20% O2 atmosphere, however, a remarkable amount of HCB formed from dust 1 above 573 K. A certain amount of HCB was also formed from dust 2, even though the initial concentration of HCB was very low. Moreover, the coexistence of metallic compounds such as CuCl2 had a significant accelerating effect on the formation of HCB.

  5. Application of alkaline solid residue of electric arc furnace dust for neutralization/purification of electroplating wastewaters.

    Science.gov (United States)

    Elez, Loris; Orescanin, Visnja; Sofilic, Tahir; Mikulic, Nenad; Ruk, Damir

    2008-10-01

    The purpose of this work was development of an appropriate procedure for the neutralization/purification of electroplating wastewater (EWW) with alkaline solid residue (ASR) by-product of the alkaline extraction of zinc and lead from electric arc furnace dust (EAFD). Removal efficiency of ASR at optimum purification conditions (pH 8 and mixing time; 20 minutes) for the elements Pb, Cr (VI), Cr (III), Fe, Ni, Cu and Zn were 94.92%, 97.58%, 99.59%, 99.48%, 97.25% and 99.97%, respectively. The concentrations of all elements in the purified wastewater were significantly lower in relation to the upper permissible limit for wastewaters suitable for discharge into the environment. The remaining waste mud was regenerated in the strong alkaline medium and successfully applied once again for the neutralization/purification of EWW. Removal efficiencies of heavy metals accomplished with regenerated waste mud were comparable to these achieved by original ASR. Elemental concentrations in the leachates of the waste mud were in accordance with regulated values.

  6. Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD). Part II: Downstream processing and zinc recovery by electrowinning.

    Science.gov (United States)

    Tsakiridis, P E; Oustadakis, P; Katsiapi, A; Agatzini-Leonardou, S

    2010-07-15

    The characterization and the agitation leaching of electric arc furnace dust (EAFD) by diluted sulphuric acid have been studied in Part I, as a separate article. The aim of the present research work (Part II) is the development of a purification process of the leach liquor for the recovery of high-purity zinc by electrowinning. The proposed hydrometallurgical process consists of the following four (4) unit operations: (1) Removal of iron as easily filterable crystalline basic sulphate salt of the jarosite type, at atmospheric pressure, by chemical precipitation at pH: 3.5 and 95 degrees C. (2) Zinc solvent extraction by Cyanex 272 at pH: 3.5, T: 40 degrees C, with 25% extractant concentration. (3) Stripping of the loaded organic phase by zinc spent electrolyte (62.5 g/L Zn(2+)) at T: 40 degrees C with diluted H(2)SO(4) (3 mol/L). (4) Zinc electrowinning from sulphate solutions (at 38 degrees C) using Al as cathode and Pb as anode. The acidity of the electrolyte was fixed at 180 g/L H(2)SO(4), while the current density was kept constant at 500 A/m(2).

  7. Evaluation of electric arc furnace-processed steel slag for dermal corrosion, irritation, and sensitization from dermal contact.

    Science.gov (United States)

    Suh, Mina; Troese, Matthew J; Hall, Debra A; Yasso, Blair; Yzenas, John J; Proctor, Debora M

    2014-12-01

    Electric arc furnace (EAF) steel slag is alkaline (pH of ~11-12) and contains metals, most notably chromium and nickel, and thus has potential to cause dermal irritation and sensitization at sufficient dose. Dermal contact with EAF slag occurs in many occupational and environmental settings because it is used widely in construction and other industrial sectors for various applications including asphaltic paving, road bases, construction fill, and as feed for cement kilns construction. However, no published study has characterized the potential for dermal effects associated with EAF slag. To assess dermal irritation, corrosion and sensitizing potential of EAF slag, in vitro and in vivo dermal toxicity assays were conducted based on the Organisation for Economic Co-operation and Development (OECD) guidelines. In vitro dermal corrosion and irritation testing (OECD 431 and 439) of EAF slag was conducted using the reconstructed human epidermal (RHE) tissue model. In vivo dermal toxicity and delayed contact sensitization testing (OECD 404 and 406) were conducted in rabbits and guinea pigs, respectively. EAF slag was not corrosive and not irritating in any tests. The results of the delayed contact dermal sensitization test indicate that EAF slag is not a dermal sensitizer. These findings are supported by the observation that metals in EAF slag occur as oxides of low solubility with leachates that are well below toxicity characteristic leaching procedure (TCLP) limits. Based on these results and in accordance to the OECD guidelines, EAF slag is not considered a dermal sensitizer, corrosive or irritant.

  8. Removal of vapour phase PCDD/Fs in electric arc furnace steelmaking emissions by sorption using plastics.

    Science.gov (United States)

    Ooi, Tze Chean; Ewan, Bruce C R; Cliffe, Keith R; Anderson, David R; Fisher, Raymond; Thompson, Dennis

    2008-08-01

    Plastics are potentially suitable for the removal of vapour phase PCDD/Fs in emissions from the electric arc furnace (EAF) steelmaking process. Three different commercial plastics, i.e. polypropylene BE170MO (Borealis A/S, Denmark), polypropylene in the form of 5 mm spheres (The Precision Plastic Ball Co. Ltd., UK) and polyethylene LD605BA (ExxonMobil Chemical, Belgium), have been studied using a novel experimental apparatus for the removal of vapour phase PCDD/Fs. Polypropylene BE170MO was identified to be the most suitable product amongst the three plastics in terms of PCDD/F sorption and potential industrial application. The optimum temperature for PCDD/F sorption on polypropylene BE170MO was below 90 degrees C for a removal efficiency of >99% at an average vapour phase PCDD/F concentration of 3.5 ng I-TEQ/Nm(3). At 130 degrees C, 53% of the PCDD/Fs trapped on polypropylene BE170MO were desorbed.

  9. Distribution of air and serum PCDD/F levels of electric arc furnaces and secondary aluminum and copper smelters.

    Science.gov (United States)

    Lee, Ching-Chang; Shih, Tung-Seng; Chen, Hsiu-Ling

    2009-12-30

    Metallurgical processes, such as smelting, can generate organic impurities such as organic chloride chemicals, polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). The objective of this study was to elucidate the serum PCDD/F levels of 134 workers and ambient air levels around electric arc furnaces (EAF), secondary copper smelters and secondary aluminum smelters (ALSs) in Taiwan. The highest serum PCDD/F levels were found in the ALSs workers (21.9 pg WHO-TEQ/g lipid), with lower levels in copper smelter workers (21.5 pg WHO-TEQ/g lipid), and the lowest in the EAF plant workers (18.8 pg WHO-TEQ/g lipid). This was still higher than the levels for residents living within 5 km of municipal waste incinerators (14.0 pg WHO-TEQ/g lipid). For ambient samples, the highest ambient air PCDD/F level was in the copper smelters (12.4 pg WHO-TEQ/Nm(3)), with lower levels in ALSs (7.2 pg WHO-TEQ/Nm(3)), and the lowest in the EAF industry (1.8 pg WHO-TEQ/Nm(3)). The congener profiles were consistent in serum and in air samples collected in the copper smelters, but not for ALSs and EAF. In secondary copper smelters, the air PCDD/Fs levels might be directly linked to the PCDD/Fs accumulated in the workers due to the exceedingly stable congener pattern of the PCDD/F emission.

  10. Inertization of pyrite cinders and co-inertization with electric arc furnace flue dusts by pyroconsolidation at solid state.

    Science.gov (United States)

    Viñals, J; Balart, M J; Roca, A

    2002-01-01

    The viability of a pyroconsolidation process to render pyrite cinders inert and to co-inert pyrite cinders with a hazardous polymetallic residue such as electric arc furnace flue dusts (EAF) containing Pb, Cu, Zn, As, Cr, Ni and Mo were investigated. The effects of pyroconsolidation temperature (800-1200 degrees C), milling pyrite cinders and additions of both CaO and EAF on the resulting microstructure of the pellets were determined. The microstructural changes were then compared with the results of the standard leaching tests. Full inertization of pyrite cinders was achieved after milling to < 100 micron followed by a pelletization and pyroconsolidation process at a temperature of 1200 degrees C. This process also allows co-inertization of pyrite cinders with controlled additions of EAF (up to approximately to 10%). Following pyroconsolidation at 1200 degrees C, the metallic elements were inert components in the four main phases: traces of Cr in hematite; Cr, Cu, Zn and Ni in spinel-phase; traces of Cr and Zn in calcium ferrites; and Pb and traces of Cu, Zn and Ba in K-Ca-Al-Fe glassy silicate.

  11. Citotoxicity status of electroplating wastewater prior/after neutralization/purification with alkaline solid residue of electric arc furnace dust.

    Science.gov (United States)

    Orescanin, Visnja; Kopjar, Nevenka; Durgo, Ksenija; Elez, Loris; Gustek, Stefica Findri; Colic, Jasna Franekic

    2009-02-15

    Toxicological safety of new procedure for the neutralisation/purification of wastewater originated from zinc plating facility was investigated. Wastewater was treated with alkaline solid residue-by-product of zinc recovery from electric arc furnace dust. For determination of cytotoxic potential of untreated and purified wastewater MTT test on HEp2 (human laryngeal carcinoma) and HeLa (human cervical carcinoma) cells lines and alkaline comet assay on human leukocytes were used. Then 100% of the sample as well as different dilutions were tested. Compared to negative control 100, 75 and 50% of the sample of untreated wastewater significantly decreased survival of both HEp2 and HeLa cell lines. In the presence of undiluted sample survival percentage of HeLa and HEp2 cells were only 2.3 and 0.3% respectively. Only undiluted purified wastewater showed slight but insignificant decrease of the survival of both cell lines. Even 0.5% of the sample of original electroplating wastewater exhibited significantly higher value of all comet assay parameters compared to negative control. There was no significant difference between negative control and purified wastewater for any of comet assay parameters. Significantly lower level of primary DNA damage recorded after treatment with purified water, even comparable with negative control, confirmed effectiveness of the purification process.

  12. HYDRAULIC AND LEACHING BEHAVIOUR OF BELITE CEMENTS PRODUCED WITH ELECTRIC ARC FURNACE STEEL SLAG AS RAW MATERIAL

    Directory of Open Access Journals (Sweden)

    Iacobescu R. I.

    2013-06-01

    Full Text Available Three belite-rich cements consisting of a clinker made with 0 (BC, 5 (BC5 and 10 wt. % (BC10 electric arc furnace steel slag (EAFS as raw material, were studied for their hydraulic and leaching behaviour. Hydration behaviour was studied by FTIR, TG/DTG and SEM analyses. The cements with EAFS resulted in a higher C2S/C3S and C4AF/C3A ratio compared to the reference body. As a result, the rate of hydration was low at early days whereas the structure was porous with scattered AFm and C–S–H crystals. At 28 days, a comparable dense microstructure consisting largely of C–S–H is observed in all mortars. Leaching was studied for V and Cr by means of tank test according to standard NEN 7345. The results showed V release below 2 μg/l. Chromium release calculated per 24 h was 1.4 μg/l in BC5 and 2.4 μg/l in BC10, which is much lower than the parametric value of 50 μg/l specified by the European Directive for drinking water (98/83/EC.

  13. Energy efficiency and emissions of arc furnaces in the steel industry; Energieeffizienz und Emissionen der Lichtbogenoefen in der Stahlindustrie

    Energy Technology Data Exchange (ETDEWEB)

    Kirschen, M.

    2007-07-01

    The operation of the electric arc furnace obeys economic constraints that require cost optimal use of the resources scrap, scrap substitutes, alloys, direct reduced iron, pig iron, oxygen, fuel gas, and energy. On the other hand, legal restrictions for minimum emissions must be observed. Comprehensive process models and strategies to optimize the EAF steel production require detailed knowledge about both energy flow rates and emissions. However, this data is often not available in the meltshop due to technical problems or high effort for maintenance of on-line off-gas analysis systems at the EAF. The Institute for Industrial Furnaces and Heat Engineering of RWTH Aachen University performed off-gas measurements at various EAFs during steel production. In some plant trials off-gas measurements were conducted simultaneously at two points in the dedusting system in order to determine the otherwise unknown volume flow rate of air at the gap between the EAF elbow and the hot gas duct. In this work, state-of-the-art off-gas analysis systems are presented. First hints for process development of particular EAFs are derived from off-gas data. Off-gas data complement the meltshop data, that are required for complete mass and energy balances. From recent energy balances, the EAF process is evaluated with respect to off-gas energy and energy efficiency. Recent energy balances from our measurements and from the literature of the last decade show total energy demand between 600 kWh/t and 850 kWh/t and energy efficiency values up to 70%. EAFs with scrap pre-heating technologies achieve highest energy efficiency values up to 70%. Measurements of off-gas and air volume flow rates monitor the efficiency of the EAF dedusting plant in combination with the EAF. With direct exhaust control based on furnace pressure measurement, the specific off-gas mass and energy is decreased significantly. Improvement of the analysis equipment for off-gas measurements at the EAF with focus on very

  14. A Laboratory Study of the Treatability of Synthetic Stormwater Under Varying Conditions Using Electric Arc Furnace Steel Slag

    Directory of Open Access Journals (Sweden)

    Nnaemeka C. Okochi

    2012-03-01

    Full Text Available The investigation of electric arc furnace (EAF steel slag as a viable add-on technology to existing stormwater systems for the removal of dissolved phosphorus (P was extended to explore the effects of varying environmental and treatment system conditions. Parameters such as stormwater composition, P concentration, metal concentration, pH, temperature, slag mass and slag particle size were varied. Observations relating to the method of P removal via EAF slag were also carefully considered to explain removal mechanisms involved. Results demonstrated that, although physisorption contributed to P reduction, it was not the key P removal mechanism. Instead, precipitation was observed to be a key removal pathway as evidenced by the correlation between the loss of iron (Fe from slag and the amount of P removed from solution. The reduced removal of P by slag in a copper-dominant stormwater solution was attributed to the formation of a stable complex formed by the interaction of copper with the slag via the ion-exchange surface model. The stability of this complex inhibits the loss of Fe from the EAF slag and, consequently, P removal by means of precipitation. In terms of the effect of changing environmental and treatment system conditions on the P removal process, stormwater composition, P concentration, metal concentration, pH, temperature, slag mass and slag particle size were found to significantly influence the effectiveness of EAF slag in removing P from a given stormwater system. It was also established that a number of combinations of these factors influence P uptake differently.

  15. Formation of the ZnFe{sub 2}O{sub 4} phase in an electric arc furnace off-gas treatment system

    Energy Technology Data Exchange (ETDEWEB)

    Suetens, T., E-mail: thomas.suetens@mtm.kuleuven.be; Guo, M., E-mail: muxing.guo@mtm.kuleuven.be; Van Acker, K., E-mail: karel.vanacker@lrd.kuleuven.be; Blanpain, B., E-mail: bart.blanpain@mtm.kuleuven.be

    2015-04-28

    Highlights: • EAF dust was characterized with particle size analysis, XRF, and EPMA. • Slag particles showed no sign of reaction with Zn vapor. • Fe{sub 2}O{sub 3} particles showed different degrees of reaction based on their size. • The thermodynamic stability of Zn vapor in EAF off-gas ducts was reevaluated. • In presence of Fe{sub 2}O{sub 3}, Zn vapor reacts to form ZnFe{sub 2}O{sub 4} and ZnO. - Abstract: To better understand the phenomena of ZnFe{sub 2}O{sub 4} spinel formation in electric arc furnace dust, the dust was characterized with particle size analysis, X-ray fluorescence (XRF), electron backscatter diffraction (EBSD), and electron probe micro-analysis (EPMA). Different ZnFe{sub 2}O{sub 4} formation reaction extents were observed for iron oxide particles with different particle sizes. ZnO particles were present as both individual particles and aggregated on the surface of larger particles. Also, the slag particles found in the off-gas were shown not to react with the zinc vapor. After confirming the presence of a ZnFe{sub 2}O{sub 4} formation reaction, the thermodynamic feasibility of in-process separation – a new electric arc furnace dust treatment technology – was reevaluated. The large air intake and the presence of iron oxide particles in the off-gas were included into the thermodynamic calculations. The formation of the stable ZnFe{sub 2}O{sub 4} spinel phase was shown to be thermodynamically favorable in current electric arc furnace off-gas ducts conditions even before reaching the post combustion chamber.

  16. Hydrometallurgical recovery of zinc and lead from electric arc furnace dust using mononitrilotriacetate anion and hexahydrated ferric chloride.

    Science.gov (United States)

    Leclerc, Nathalie; Meux, Eric; Lecuire, Jean Marie

    2002-04-26

    The purpose of this work was to study the feasibility at laboratory-scale of a new hydrometallurgical process for treating electric arc furnace dusts (EAFD). The proposed process is intended to extract zinc and lead from EAFD without destroying the iron oxides matrix. So, this material can be recycled by the steel industry. Independently of the origin of the samples, major mineralogical forms present in these wastes are Fe3O4, ZnO, ZnFe2O4 and PbOHCl. The proposed process consists of a hydrometallurgical treatment of wastes based on selective leaching of zinc and lead. Initially, a leaching is carried out utilizing a chelating agent, nitrilotriacetate anion (NTA3-), as the protonated form HNTA2-. Treatment of five EAFD samples for an hour at room temperature with a molar solution of reagent results in total leaching of the ZnO. In all cases the solubilized iron does not exceed 3 wt.%. The recovery of zinc and lead is performed by precipitation of metallic sulfides with a solution of Na2S4 sodium tetrasulfide 2M. These metallic sulfides can be used as metallurgical raw materials and the chelating reagent can be reused in the process after pH adjustment. The results of the normalized leaching test AFNOR X31-210 conducted on the leaching residues, shows that all the samples meet acceptance thresholds for hazardous wastes landfill. However, the residues contain a considerable amount of zinc as ZnFe2O4. The extraction of the zinc element requires the destruction of the ferrite structure. In this process, ZnFe2O4 is treated by FeCl3.6H2O. The reaction consists in a particle O2-/Cl- exchange allowing the recovery of zinc as ZnCl2 and iron as hematite Fe2O3. The separation of these products is accomplished by simple aqueous leaching. All of the zinc is extracted in a 8h treatment at 150 degrees C with a molar ratio FeCl3.6H2O/ZnFe2O4 equal to 10. Ultimate solid residues, which have been concentrated in iron, can be oriented towards the steel industry.

  17. 真空电弧炉升降机构的ANSYS优化设计%ANSYS optimization design of lifting mechanism of the vacuum arc furnace

    Institute of Scientific and Technical Information of China (English)

    张以忱; 王德志; 王永杰; 魏永秋

    2011-01-01

    A mechanical model was developed for the lifting mechanism of a prototype of the VCF -3t cantilevered vacuum arc furnace, the position and value of maximum stress of the column was obtained through force analysis of the main bearing parts ( such as column). Then the actual equipment model was simplified to establish finite element model and the stress cloud chart was compared with actual calculated value in order to test the correctness of the finite element model. On this base, combined with the relationships among actual structure sizes of the furnace, the parametric finite element model was established. If the model meet conditions of intensity and stiffness etc. , the radius and thickness of the column and furnace body was optimized with the optimizer of ANSYS to make the mass of mechanical structure to be the lightest and make full use of the material's property. At the same time, VB language was used in the call analysis interface in ANSYS to provide an intuitive man - machine system in order to decrease duplication of workload in series design of product. The parameter optimization method used in this paper is an important development of structural optimization design method and has important practical value in the structural design.

  18. Behaviour of radionuclides during accidental melting of orphan sources in electric arc furnaces by means of C.F.D. gas flow modeling

    Energy Technology Data Exchange (ETDEWEB)

    Penalva, I.; Damborenea, J.; Legarda, F. [University of the Basque Country, Nuclear Engineering and Fluids Mechanics (Spain); Zuloaga, P.; Ordonez, M. [Empresa Nacional de Residuos Radiactivos, SA (ENRESA), Madrid (Spain); Serrano, I. [Consejo de Seguridad Nuclear, Madrid (Spain)

    2006-07-01

    The appearance of orphan sources in steelmaking facilities has become a fact nowadays. Radiation sources, hidden within the scrap, may come into the scrap yard and become part of the melting. As a result, dispersion of the radioactive material that makes up the source takes place throughout the facility. The University of the Basque Country (U.P.V.-E.H.U.), in collaboration with the Empresa Nacional de Residuos Radiactivos, S.A. (E.N.R.E.S.A.) and the Consejo de Seguridad Nuclear (C.S.N.), has carried out a Research Project to analyze this accidental melting of radioactive sources in electric arc furnaces (E.A.F.). The whole steelmaking process can be analyzed in several discrete phases. Radioactive sources that may be incorporated to this process will be exposed to the different critical conditions prevailing during each phase. In this sense, Computational Fluid Dynamics (C.F.D.) has been used in order to recreate such conditions and so, determine the characteristics of the dispersion of radioactivity. Two different situations have been studied in detail using C.F.D. techniques: thermal conditions around a scrap-basket that contains the source just before entering the furnace and the deposition of steelmaking dust containing {sup 137}Cs on the inner surface of flue pipes. Before entering the furnace, scrap is usually placed inside a basket that remains above the furnace during some time. Once the furnace is open the scrap is dropped into the furnace to complete the loading process. C.F.D. techniques have been used to analyze the thermal conditions around the basket in order to assess the possibility of a break of the radioactive source hidden within the scrap, concluding that commercial sources will maintain their integrity during the whole loading process. On the other hand, after entering the furnace dispersion of the radioactive material will take place. Physical and chemical properties of the active elements (chemical form, composition, melting point, etc

  19. 矿热炉保护套的优化设计%The Optimization Design of Protective Jacket of Submerged Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    李峰; 王静; 杨树明

    2012-01-01

    A new-style water cooling protective jacket structure of submerged arc furnace was designed according to practical experiences of existing insufficient structures, and applied liquid finite element analysis software FLUENT to optimize structure of the new-style water cooling protective jacket, finally advanced a effective improved structure and achieved good results.%针对现有矿热炉水冷保护套的结构不足,提出一种新型的矿热炉水冷保护套结构,并采用流体有限元分析软件FLUENT对新型水冷保护套的结构进行优化设计,最终提出一种合理的结构,该结构在实际应用中取得了良好的效果.

  20. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing.

    Science.gov (United States)

    Liapis, Ioannis; Papayianni, Ioanna

    2015-01-01

    Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  1. Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing

    Energy Technology Data Exchange (ETDEWEB)

    Liapis, Ioannis, E-mail: iliapis@sidenor.vionet.gr [AEIFOROS SA, 12th km Thessaloniki-Veroia Rd, PO Box 59, 57008 Ionia, Thessaloniki (Greece); Papayianni, Ioanna [Laboratory of Building Materials, Department of Civil Engineering, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

    2015-02-11

    Highlights: • Addition of 10% perlite decreases specific weight of the slag by approx. 7.5%. • Slag-crucible interaction and thin coating layer result in variations in XRF. • XRD shows high glass content and smaller crystalline sizes due to rapid cooling. • SEM shows higher homogeneity and lower crystallisation for SiO{sub 2}/CaO-rich samples. • Physical properties (LA, PSV, AAV) of modified slag show limited deterioration. - Abstract: Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector.

  2. Control system of constant power consumption melting speed for vacuum arc furnace%真空自耗电弧炉恒熔速控制系统改造

    Institute of Scientific and Technical Information of China (English)

    王勃; 陈鼎; 孙足来

    2015-01-01

    为真空自耗电弧炉设备由恒电压控制升级改造至恒熔速控制系统。通过对2000kg真空自耗电弧炉熔炼钛合金的生产工艺、过程参数、产品要求进行了详细分析,选取恰当的数据采样算法,为更好的掌握真空弧电压、真空弧电流、钛合金熔炼速度等工艺参数间的耦合关系提供了良好的依据。同时对真空自耗电弧炉的控制系统现状及熔炼技术发展做了综述。在 PLC中建立弧电压、弧电流,熔炼速率等的计算公式来实现设定各级控制回路的设定值。%In this paper, the control system of electricity arc furnace equipment is upgraded from constant voltage to constant melting speed. The power consumption of vacuum arc furnace selfmelting production technology of titanium alloy, process parame-ters and product requirements are analyzed in detail. The data sampling algorithm was selected appropriately in order to better grasp the vacuum arc current, arc voltage, the coupling relationship between process parameters such as titanium alloy melting speed so as to provide good basis. At the same time, the development of the current control system and self-melting technology for power consumption vacuum arc furnace were reviewed. The calculation formula of arc voltage, arc current and melting rate were built up in PLC to implement the control circuit at various levels.

  3. Synthesis of TiO2 visible light catalysts with controllable crystalline phase and morphology from Ti-bearing electric arc furnace molten slag.

    Science.gov (United States)

    Li, Yang; Liu, Lulu; Guo, Min; Zhang, Mei

    2016-09-01

    TiO2 visible light catalysts with different crystalline phases and morphologies were synthesized from titanium-bearing electric arc furnace molten slag (Ti-bearing EAF slag) by using a simple acidolysis process. The effects of the pH of the HCl solution, liquid to solid ratio (RL/S, HCl solution to the residue ratio, mL/g) and acidolysis time on the micro-morphology and crystalline phase of as-prepared TiO2 photocatalysts were systematically investigated. The results indicated that with decreasing pH in the HCl solution and increasing RL/S, the crystalline phase and micro-morphology of the obtained TiO2 nanostructures tended to transform from anatase type TiO2 with spherical nanoparticle structures to rutile type TiO2 with needle-like nanorod structures. The acidolysis time had little influence on the crystalline phase but great impact on the size of the obtained TiO2. The growth mechanism of TiO2 from Ti-bearing EAF slag during the acidolysis process was also discussed. In addition, the influence of RL/S on the photocatalytic properties of the synthesized nanostructured TiO2 was studied. The results showed that the photodegradation efficiency for Rhodamine B solution could reach 91.00% in 120min when the RL/S was controlled at 50:1.

  4. Chemical characterization of dust particles recovered from bag filters of electric arc furnaces for steelmaking: some factors influencing the formation of hexachlorobenzene.

    Science.gov (United States)

    Tsubouchi, Naoto; Hashimoto, Hiroyuki; Ohtaka, Noriaki; Ohtsuka, Yasuo

    2010-11-15

    To make clear some factors controlling the formation of hexachlorobenzene (HCB) in the process of electric arc furnace (EAF) steelmaking, six dust samples recovered from different bag filters in commercial EAF steelmaking plants have been characterized with XRD, SEM-EPMA, XPS and temperature-programmed desorption (TPD) techniques. These dust samples contain 1.9-8.0 mass% of chlorine element, and the XPS and TPD measurements exhibit that the Cl is enriched at the dust surface and composed of the inorganic and organic functionalities, part of the Cl being evolved as HCl in the temperature region of flue gas treatment. All of the samples also include 2.1-6.4 mass% of carbon element, and some of the C can release CO(2) in the TPD up to 300°C to form active carbon sites. The number is related closely to HCB concentration of each dust. Further, it is suggested that the Zn present in the samples consists of ZnFe(2)O(4), ZnO and surface ZnCO(3), and the dust with a larger content of the ZnCO(3) has a higher concentration of HCB. It is possible that HCB formation occurs via gas-solid-solid interactions among gaseous Cl-containing compounds in flue gas, active carbon sites and surface Zn-species produced in exhaust ducts and bag filters.

  5. On the distribution and bonding environment of Zn and Fe in glasses containing electric arc furnace dust: a mu-XAFS and mu-XRF study.

    Science.gov (United States)

    Pinakidou, F; Katsikini, M; Paloura, E C; Kavouras, P; Kehagias, Th; Komninou, Ph; Karakostas, Th; Erko, A

    2007-04-02

    We apply synchrotron radiation assisted X-ray fluorescence (SR-XRF), SR-XRF mapping as well as micro- and conventional X-ray absorption fine structure (mu-XAFS and XAFS) spectroscopies in order to study the bonding environment of Fe and Zn in vitrified samples that contain electric arc furnace dust from metal processing industries. The samples are studied in the as-cast state as well as after annealing at 900 degrees C. The SR-XRF results demonstrate that annealing does not induce any significant changes in the distribution of either Fe or Zn, in both the as-cast and annealed glasses. The mu-XAFS spectra recorded at the Fe-K and Zn-K edges reveal that the structural role of both Fe and Zn remains unaffected by the annealing procedure. More specifically, Fe forms both FeO(6) and FeO(4) polyhedra, i.e. acts as an intermediate oxide while Zn occupies tetrahedral sites.

  6. Extraction of Zinc from Electric Arc Furnace Dust by Alkaline Leaching Followed by Fusion of the Leaching Residue with Caustic Soda

    Institute of Scientific and Technical Information of China (English)

    赵由才; R.Stanforth

    2004-01-01

    Extractability of zinc from two types of electric arc furnace (EAF) dusts containing 24.8% and 16.8% of zinc respectively (denoted as Sample A and Sample B) were tested using direct alkaline leaching followed by fusion of the resulting leaching residues with caustic soda. The experimental results show that the extraction of zinc is heavily dependent on the contents of iron in the dusts. The higher iron content, the lower extraction of zinc is obtained. 53% and 38% of zinc can be extracted when both dusts were directly contacted with 5mol·L-1 NaOH solution for 42h. The remaining zinc left in the leaching residues, which supposed to be present as zinc ferrites, can be further leached when the residues were fused with caustic soda. Quantitative extraction of zinc can be obtained from the leaching residue of Sample A while only 85% from Sample B. The extractability of zinc from dusts wit hvarious contents of iron is compared. The production flowsheet for zinc from the dusts using the process proposed is discussed.

  7. Waste heat recovery with heat pipes in the modern electric arc furnace process%电炉流程中热管式余热回收

    Institute of Scientific and Technical Information of China (English)

    杨振国; 刘青; 谢银幕

    2011-01-01

    结合国内外电炉烟气热量处理的现状,分析了热管式余热回收的原理及特点,研究了其系统的结构特点、工艺流程、关键参数以及如何使系统产生的蒸汽质量满足VD(RH)炉生产的要求,并对其在莱钢50t电炉余热回收中的工程应用情况进行了阐述,指出该技术具有良好的应用前景.%The principle and characteristic of waste heat recovery with heat pipes were analyzed in combination with the present condition of utilizing electric arc furnace(EAF) flue gas at home and abroad.The structure character,technical processes,and key parameters of this system were studied comprehensively.How to make high quality steam to meet the demand of VD(RH) furnaces was also discussed.A practical application of waste heat recovery in 50t EAF in Laiwu Steel shows a good prospect of the technology.

  8. Optimization of melting process of 50 t ultra-high electric arc furnace%50t超高功率电弧炉冶炼工艺优化

    Institute of Scientific and Technical Information of China (English)

    杨振国; 刘青; 王彬; 石荣山

    2012-01-01

    对山东钢铁股份有限公司莱芜分公司50t超高功率电弧炉冶炼工艺和生产数据进行解析,通过对不同人炉铁水比例的物料平衡、热平衡计算和生产实践,得出了电炉工序冶炼电耗、氧气消耗参数,提出了4种工况下的冶炼操作模型,对同类型电炉生产具有相当的参考价值。%The steelmaking process and the production data ot 50 t ultra-high power elec- tric arc furnace are analyzed in this paper, and the values of electric power consumption and oxygen consumption are gained by the EAF mass and heat balance calculation of dif- ferent hot metal charged ratio, including production practice in Laiwu Steel Pants. Then four steelmaking operation models for different working conditions helpful for the same kind of EAF plants are put forward.

  9. Characterisation of the sintering behaviour of Waelz slag from electric arc furnace (EAF) dust recycling for use in the clay ceramics industry.

    Science.gov (United States)

    Quijorna, N; de Pedro, M; Romero, M; Andrés, A

    2014-01-01

    Waelz slag is an industrial by-product from the recovery of electric arc furnace (EAF) dust which is mainly sent to landfills. Despite the different chemical and mineralogical compositions of Waelz slag compared to traditional clays, previous experiments have demonstrated its potential use as a clay substitute in ceramic processes. Indeed, clayey products containing Waelz slag could improve mechanical and environmental performance, fixing most of the metallic species and moreover decreasing the release of some potential pollutants during firing. However, a deeper understanding of the complex phase transformations during its thermal treatment and the connection of this behaviour with the end properties is desirable in order to explain the role that is played by the Waelz slag and its potential contribution to the ceramic process. For this purpose, in the present study, the chemical, mineralogical, thermal and environmental behaviour of both (i) unfired powdered samples, and (ii) pressed specimen of Waelz slag fired up to different temperatures within the typical range of clay based ceramic production, has been studied. The effect of the heating temperature on the end properties of the fired samples has been assessed. In general, an increase of the firing temperature promotes sintering and densification of the products and decreases the open porosity and water absorption which also contributes to the fixation of heavy metals. On the contrary, an increase in the leaching of Pb, Cr and Mo from the fired specimens is observed. This can be attributed to the creation of Fe and Ca molybdates and chromates that are weakly retained in the alkali matrix. On the other side, at temperature above 950 °C a weight gain related to the emission of evolved gases is observed. In conclusion, the firing temperature of the ceramic process is a key parameter that affects not only the technical properties but also strongly affects the leaching behaviour and the process emissions.

  10. Metals purification by improved vacuum arc remelting

    Science.gov (United States)

    Zanner, Frank J.; Williamson, Rodney L.; Smith, Mark F.

    1994-12-13

    The invention relates to improved apparatuses and methods for remelting metal alloys in furnaces, particularly consumable electrode vacuum arc furnaces. Excited reactive gas is injected into a stationary furnace arc zone, thus accelerating the reduction reactions which purify the metal being melted. Additionally, a cooled condensation surface is disposed within the furnace to reduce the partial pressure of water in the furnace, which also fosters the reduction reactions which result in a purer produced ingot. Methods and means are provided for maintaining the stationary arc zone, thereby reducing the opportunity for contaminants evaporated from the arc zone to be reintroduced into the produced ingot.

  11. Exposure assessment of workers to airborne PCDD/Fs, PCBs and PAHs at an electric arc furnace steelmaking plant in the UK.

    Science.gov (United States)

    Aries, Eric; Anderson, David R; Fisher, Raymond

    2008-06-01

    Occupational exposure studies were undertaken at a UK electric arc furnace (EAF) steelmaking plant to investigate the exposure of workers via inhalation to dioxins, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) including benzo[a]pyrene (B[a]P). Surveys were undertaken in areas including the melting shop, the casting department and a furnace control cabin. The highest concentrations of dioxins and PCBs were found inside the melting shop nearby EAFs, whereas dioxin and PCB concentrations in the casting department and inside the control cabin were significantly lower. Risk characterization was carried out by comparing the daily intake of dioxins and PCBs through inhalation with the recommended tolerable daily intake (TDI). Health risk assessments were also carried out by combining exposure data with inhalation cancer potency factors to quantify the cancer risk. For the most exposed category of workers (melting shop workers), the estimated daily intake via inhalation was 0.35 pg WHO-TEQ kg(-1) body weight (bw) in the worst case scenario. Considering that the average UK adult exposure to dioxins from the diet is 1.8 pg WHO-TEQ kg(-1) bw day(-1), the results indicated that the estimated daily intake of dioxins via inhalation at the EAF would not result in the recommended range of the TDI (1-4 pg WHO-TEQ kg(-1) bw day(-1)) being exceeded. Cancer risks for a 40-year occupational exposure period were determined by multiplying the inhalation dose by the inhalation cancer potency factor for 2,3,7,8-tetrachlorodibenzo-p-dioxin. For melting shop workers, cancer risks from exposure to dioxins and PCBs ranged from 2.05 x 10(-5) to 7.54 x 10(-5). Under most regulatory programmes, excess cancer risks between 1.0 x 10(-4) and 1.0 x 10(-6) indicate an acceptable range of excess cancer risk, suggesting a limited risk from dioxin exposure for workers in the EAF plant. For the calculation of excess cancer risks, no account has been taken of the protection

  12. Influence of Na2O/Al2O3 and SiO2/Al2O3 ratios on the immobilization of Pb from electric arc furnace into the fly ash based geopolymers

    Directory of Open Access Journals (Sweden)

    Zejak R.

    2013-04-01

    Full Text Available Electric arc furnace dust (EAFD is by-product of iron and steel scrap remelting in electric arc furnace. This waste is classified as a hazardous material due to the leaching of heavy metals into the environment. Geopolymeryzation of fly ash into construction materials called - geopolymer is a considering as a possible way of immobilization of heavy metals from EAFD. Mechanical properties and chemical stability of geopolymers are mostly determined by the ratio between main oxides, Na2O, Al2O3 and SiO2. In this paper we have investigated possibility of Pb immobilization from EAFD into the fly ash based geopolymer. Geopolymers are synthesized at different Na2O/Al2O3 and SiO2/Al2O3 ratios. Compressive strength and chemical stability of geopolymers with respect to the leaching of Pb in water according to the EN 12457 regulation were tested. The results have shown that Na2O/Al2O3 and SiO2/Al2O3 ratios have influence on the compressive strength of geopolymers and Pb release in the water environment.

  13. Micro-structural and chemical characterization of electric arc furnace slag%电弧炉炉渣的显微结构和化学特性

    Institute of Scientific and Technical Information of China (English)

    Mapelli C; Mombelli D; Gruttadauria A; Baldizzone C; Magni F; Levrangi P L; Simone P

    2012-01-01

    Steel slag represents an excellent opportunity for their use as alternative cement materials. Specifically black slag produced during the melting process in EAF (Electric Arc Furnace) can be used as adjunct in the operation of land-filling, in the building operation of road grounds and in the production of concrete. Their use limitation is due to the presence of polluting chemical elements, including Cr, Ba, V, Mo, etc, that can be dangerous for humans and the environment, resulting from the use of polluted scraps. Several experimental trials have been performed on the slag provided by two Italian steelmaking plants producing reinforcing bars. The chemical compositions of the final obtained slag belong to a range in which the slag has shown a releasing behaviour that is significantly different as a function of the different ratios among the fundamental constituting chemical species, I. E. CaO, SiO2, Al2 O3, MgO etc.. The chemical composition has been characterized through the optical basicity and the slag has been investigated from a micro-structural point of view through scanning electron microscopy techniques that permitted to identify the main phases contained in the slag and to characterize their chemical composition and the dangerous polluting elements solved in each phase. The combination of the data coming from chemical analysis, micro-structural examination and the releasing tests allowed to identify a specific chemical composition range preventing dangerous chemical releasing. Such break though has provided the possibility to identify a correct procedure for treating and modifying the slag.%炉渣材料代替水泥是一个很好的选择.特别是电弧炉(EAF)熔融过程中产生的炉渣,可作为填埋道路场地和生产混凝土的材料.但是炉渣中含有污染性的化学元素,如铬、钡、钒、钼等,使其应用受到限制.本文时两个生产钢筋的意大利炼钢厂的炉渣进行了测试.结果表明,炉渣的化学成分在一

  14. Application of Fuzzy Control Based on SIEMENS PLC in Electrode Regulating System of Electric Arc Furnace%基于西门子PLC的模糊控制在电弧炉电极调节中的应用

    Institute of Scientific and Technical Information of China (English)

    刘文远; 毛一之; 杨子亮

    2012-01-01

    Aiming at the electrode regulating system of electric arc furnace have the characteristics of non-linearity, long time lag , time variable, etc .proposed that the advanced fuzzy control was applied to electric arc furnace electrode regulator system to improve the system performance. Proved by mathematical that the simulation of fuzzy control regulation is superior to the original dead-time control. According to the features of PLC and the principle of fuzzy control, proposed the method of realizing fuzzy control through software programming based on Siemens S7 -400. So on the basis of the original system can improve the regulation, without additional hardware, to reduce the cost of renovation.%针对电弧炉电极调节系统具有非线性、大时滞及时变性等特点,提出将先进的模糊控制应用到电弧炉电极调节系统中来改善系统的调节性能.通过数学仿真证明模糊控制调节性能明显优于原来的死区控制.结合PLC的特点以及模糊控制原理,提出了将模糊控制在西门子S7-400中通过软件编程来实现的方法.这样在原来的基础上既能改善系统的调节性能,又不增加硬件设备,降低改造成本.

  15. Producción de aceros al carbono en hornos de arco eléctrico en condiciones de mineral de manganeso. // Steel production in electric arc furnaces in the condition of use of manganese.

    Directory of Open Access Journals (Sweden)

    E. E. Navas Medina

    2007-05-01

    Full Text Available El presente trabajo constituye una segunda etapa de investigación relacionada con la producción de acero en hornos de arcoeléctrico con revestimiento básico en condiciones de utilización de mineral de manganeso como sustituto del ferromanganeso.En la investigación se caracteriza el acero producido utilizando el mineral de manganeso en dos variantes tecnológicasdiferentes y se determinan parámetros importantes, tales como la estructura del acero obtenido, la influencia de lacomposición química y la temperatura en la reducción del Mn. Adicionalmente, se determina la composición química de laescoria, su basicidad e influencia en el aprovechamiento del Mn del mineral, así como, lo que significa la sustitución delFeMn en la problemática medioambiental.Palabras claves: Producción de aceros al carbono, hornos de arco eléctricos, mineral de manganeso.______________________________________________________________________________Abstract:This present work constitutes the second stage of investigation in relation with the steel production bymeans of electric arc furnaces in the condition of use of manganese ores as a substitute of theferromanganese. In the investigation, the steel manufactured is analyzed the manganese ore in twodifferent technological variants and some important parameters are determined such as: the chemicalcomposition's structure of the steel, the influence of temperature in the reduction of Mn. Moreover, ananalysis of the chemical composition of the slag and the influence in the environmental is realized.Key words: Carbon steel production, electric arc furnaces, manganese mineral.

  16. 矿热炉节电控制在线数学模型解析%Analysis on online mathematical model for submerged arc furnace power-saving control

    Institute of Scientific and Technical Information of China (English)

    罗凡; 陈杰; 金鑫; 吴伟; 焦克新

    2013-01-01

    Through real-time production data acquisition and chemical composition analysis of raw materials from a 25 500 kV · A calcium carbide furnace in a calcium carbide factory, dynamic material balance and heat equilibrium were calculated, and an online mathematical model for power-saving control of submerged arc furnace was established.Thus the calcium carbide liquid ingredients,gas composition,and energy consumption of each calcium carbide production unit could be predicted in real-time and material flow and energy flow in the calcium carbide furnace could be quantified.Finally ,the optimization for the calcium carbide liquid discharged management control and online monitoring of calcium carbide furnace electricity consumption were realized.Through calculation,the power consumption of production 1 t of calcium carbide fluid was 3 205.78 kW ·h, reduced by about 100 kW-h compared with the average power consumption before management optimization.The energy utilization ratio was 50.03%,and the sensible heat taken away by the products was 22.83%.%通过对某电石厂25 500 kV·A电石炉实时生产数据的采集和原料化学成分的检测,进行了动态物料平衡和热量平衡计算,建立了矿热炉节电控制在线数学模型,从而对电石液成分、煤气成分、电石生产各个部分的能量消耗进行实时预测,定量化电石炉内的物质流和能量流动态,实现对电石液排放的优化管理控制及电石炉电能消耗的在线监测.经计算,生产1t电石液电能消耗量为3 205.78 kW·h,比优化管理前电耗平均值降低约100 kW·h.电能利用率为50.03%,产物带走的显热占22.83%.

  17. Utilización de las escorias de los hornos de arco eléctrico y de cuchara como materiales de construcción. // Use of slags from ladle and electric arc furnaces as construction materials.

    Directory of Open Access Journals (Sweden)

    R. Zaragoza Valdés

    2001-01-01

    Full Text Available La necesidad que tiene la humanidad de que las producciones sean cada día mas limpias, así como la que tiene el país del aumento dela rentabilidad de las empresas, hace necesario el estudio del uso de las escorias que se obtienen en la producción de acero, principalresidual de este tipo de producción. En el trabajo se estudia la utilización de la escoria del Horno de Arco Eléctrico (HAE comomaterial de relleno en la confección de bloques de hormigón para la construcción de edificaciones, sustituyendo la grava de granito.Se estudia, además, el uso de la escoria de los hornos cuchara (HC como sustituto del clinquer en la fabricación de cementosportland. Se obtienen resultados positivos para la protección del medio ambiente y la economía de la empresa metalúrgica.Palabras claves: producción de acero, escorias, medio ambiente, cementos, materiales para la construcción.________________________________________________________________________________Abstract:The existing necessity of clean productions as welll as the profitability of enterprises that the Cuban economy is demanding makes itnecessary to carry out a study of slags that constitute t he main residue of the steel production. This paper presents the use of slags comingfrom electric arc furnaces (EAF as a substitute for gravel in the production of concrete bricks. The use of slags coming from ladle furnaces(LF to replace clinker in the production of Portland Cement is also shown. Positive results are obtained such as the protection of theenvironment and the economic growth of the enterperise.Key words:Steel making, slags, environment protection, cement, construction materials.

  18. Research on Zinc Extraction with Electric Arc Furnace Dust%电弧炉烟尘湿法提锌研究

    Institute of Scientific and Technical Information of China (English)

    罗伟; 徐政; 张寒霜; 杨丽梅; 李岩

    2011-01-01

    The electric are furnace dust in Jiangsu Sugang Group contains Zn content of 15.4% and is mainly embedded in zinc ferrite. Results of the leaching tests on this dust showed that only 34.0% of zinc was extracted when sodium hydroxide as lixiviant in alkaline leaching. And about 98.7% of zinc was leached out with sulphuric acid as lixiviant under the experimental conditions of stirring at 420 r/min, 200 g/L of H2SO4 , reaction temperature 90 ℃, liquid to solid ratio 10:1 and reaction time 2 h.%江苏苏钢集团电弧炉炼钢烟尘含锌15.4%,并主要分布在铁酸锌中.对该炼钢烟尘进行浸出试验,结果表明:以氢氧化钠为浸出剂进行碱性浸出时,锌的浸出率仅为34.0%;以硫酸为浸出剂进行酸性浸出时,在搅拌转速为420 r/min,硫酸浓度为200 g/L,液固比为10:1,反应温度为90 ℃,浸出时间为2 h的条件下,锌的浸出率达到98.7%.

  19. 基于电压同步对称分量法的SVC在电弧炉中的应用%Application of SVC Based on the Method of Valtage Synchronous Symmetrical Component in Electric Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    吴桂峰

    2011-01-01

    According to the power quality problems when AC-EAF in operation of a steel company in Zhejiang, a set of new TCR+FC-type static var compensator (SVC) technology project is proposed. According to the symmetric component method, the reactive compensator admittance based on voltage synchronous symmetric component method of three phase imbalance was deduced. Through the simulation software CHP simulating the system, the results indicate that the SVC device can manage the power quality problems caused by electric arc furnace effectively, has a good compensation performance and a good engineering application effect.%针对浙江某钢厂交流电弧炉运行时给电网中其他用户带来的电能质量问题,提出了一套新型的TCR+FC型静止无功补偿装置(SVC)技术方案.根据对称分量法推导出了基于电压同步对称分量法的三相不平衡SVC无功补偿导纳实用算法,通过仿真软件CHP对该系统进行了仿真,结果表明该SVC装置能够有效治理由电弧炉引起的电能质量问题,并且补偿性能良好,具有较强的工程实用性.

  20. Development of processes for zircaloy chips recycling by electric arc furnace remelting and powder metallurgy; Desenvolvimento de processos de reciclagem de cavacos de zircaloy via refusao em forno eletrico a arco e metalurgia do po

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Luiz Alberto Tavares

    2014-09-01

    PWR reactors employ, as nuclear fuel, UO{sub 2} pellets with Zircaloy clad. In the fabrication of fuel element parts, machining chips from the alloys are generated. As the Zircaloy chips cannot be discarded as ordinary metallic waste, the recycling of this material is important for the Brazilian Nuclear Policy, which targets the reprocess of Zircaloy residues for economic and environmental aspects. This work presents two methods developed in order to recycle Zircaloy chips. In one of the methods, Zircaloy machining chips were refused using an electric-arc furnace to obtain small laboratory ingots. The second one uses powder metallurgy techniques, where the chips were submitted to hydriding process and the resulting material was milled, isostatically pressed and vacuum sintered. The ingots were heat-treated by vacuum annealing. The microstructures resulting from both processing methods were characterized using optical and scanning electron microscopy. Chemical composition, crystal phases and hardness were also determined. The results showed that the composition of recycled Zircaloy comply with the chemical specifications and presented adequate microstructure for nuclear use. The good results of the powder metallurgy method suggest the possibility of producing small parts, like cladding end-caps, using near net shape sintering. (author)

  1. Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and trace metals in the blood of nonoccupationally exposed residents living in the vicinity of a municipal solid waste incinerator and electric arc furnace.

    Science.gov (United States)

    Chen, Yan-Min; Lin, Yuan-Chung; Wu, Tzi-Yi; Chang-Chien, Guo-Ping; Ma, Wen-Feng

    2010-06-01

    This study examines levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and trace metals in the blood of the nonoccupationally exposed residents living in the vicinity of municipal solid waste incinerators (MSWIs) and electric arc furnaces (EAFs). The analysis found that older females had higher concentrations of PCDD/Fs and older males had higher body mass index (BMI) values and higher concentrations of PCDD/Fs. Moreover, sex appeared to affect the levels of PCDD/Fs because, overall, females showed higher levels of PCDD/Fs. The results of a principal component analysis indicated that the characteristics of the blood were more similar to the characteristics of the stack flux gas in MSWIs than those in EAFs. When sex, age, and BMI values were taken into consideration, none of the factors appeared to significantly affect PCDD/F and trace metal blood levels. However, when participants were divided into eight categories and analyzed, it was found that sex was the most important factor affecting levels of trace metals in blood and that males had higher concentrations of Pb, Al, Cd, and Cu.

  2. Laboratory experiments on arc deflection and instability

    Energy Technology Data Exchange (ETDEWEB)

    Zweben, S.; Karasik, M.

    2000-03-21

    This article describes experiments on arc deflection instability carried out during the past few years at the Princeton University Plasma Physics Laboratory (PPPL). The approach has been that of plasma physicists interested in arcs, but they believe these results may be useful to engineers who are responsible for controlling arc behavior in large electric steel furnaces.

  3. APPLICATION OF REVERSE OSMOSIS TECHNOLOGY TO THE DESALINATION PROCESS IN SUPPLEMENT WATER FOR SUBMERGED ARC FURNACE%反渗透技术在矿热炉补充水除盐工艺的应用

    Institute of Scientific and Technical Information of China (English)

    吴秋勤; 曾世林; 王正

    2015-01-01

    This paper introduced the application of reverse osmosis technology to the desalination process in supplement water for submerged arc furnace. It tested the effects of original water suspended matter concentration,hardness and static pressure difference both sides of RO membrane on system operation, water yield and desalination rate. The result shows that original water suspended matter has great effects on system water production and original water hardness has less ef-fect on RO water production. It is beneficial to enhance desalination to decrease the static pressure difference both sides of RO membrane. It plays a key role in normal operation of system to increase combined deep pretreatment, decrease the original water concentration and strengthen germicide and algicide in pretreatment stage.%介绍了反渗透技术在矿热炉补充水除盐工艺中的应用,并进行了原水悬浮物浓度、硬度和RO膜两侧静压差对系统运行状况、产水量和除盐率影响的测试.结果表明,原水悬浮物对系统产水量有严重影响;原水硬度对RO产水量影响相对较小;RO膜两侧静差降低,有利于提高除盐率.增加组合深度预处理工序,降低原水的悬浮物浓度,强化预处理阶段杀菌灭藻,对除盐系统设备正常运行起关键作用.

  4. Emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from both of point and area sources of an electric-arc furnace-dust treatment plant and their impacts to the vicinity environments.

    Science.gov (United States)

    Yu, Kuei-Min; Lee, Wen-Jhy; Tsai, Perng-Jy; Fang, Kenneth; Lin, Mark

    2010-08-01

    This study was set out to investigate emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from both the stack (i.e., point source) and plant fugitives (i.e., area source) of an electric-arc furnace-dust treatment plant (EAFDTP) and their impact to the vicinity environments. The emission rate of the point source (2,360 ng I-TEQh(-1)) was determined directly by measuring PCDD/F concentrations of the stack flue gas. The emission rate of the area source (1,080 ng I-TEQ m(-2)h(-1)) was estimated by using the Industrial Sources Complex Short-Term (ISCST3) model based on concentrations measured at the downwind side of the plant. The mean emission factors of 785 and 893 ng I-TEQ ton(-1) ZnO were found for the point and area source, respectively. The above results suggest that the area source accounted for more than 50% of total PCDD/F emissions for the selected EAFDTP. The contribution of the point source to the atmospheric PCDD/F concentrations of the upwind site and downwind site of the EAFDTP were 0 and 0.27 fg I-TEQ Nm(-3), respectively. The contributions of the area source were 0.020 and 3.3 fg I-TEQ Nm(-3), respectively. The total contribution of the selected EAFDTP (including both the point and area sources) to the concentrations in both upwind and downwind side vicinities were all less than 10%. Finally, the impact of PCDD/F emissions from the selected EAFDTP to the vicinity atmospheric environments was discussed in the present study.

  5. 测定电弧炉中燃烧器喷尖“距废料距离”的SERAFIN传感器%SERAFIN sensor in the determination of "Distance-to-scrap" at burner tip in electric arc furnace

    Institute of Scientific and Technical Information of China (English)

    Mathy; Monfort G; Vanderheyden B; TussetV

    2011-01-01

    开发了用以测定电弧炉(EAF)中燃烧器喷尖“距废料距离”的SERAFIN传感器,同时讨论了其具有监测熔化废钢的工艺优点.详细描述了传感器测量原理和光学测量头的设计特点.SERAFIN传感器是一种适用于环形燃烧器、组合燃烧器以及氧气喷枪内部的在线测量“距废料距离”的测量技术,工业试验表明运用此传感器可以监测每个注射器前面废料的熔化情况,进而优化其操作,并可在发生损坏前检测逆吹情况.仪表盘过热比较结果表明其可以用于逆吹倾向的预测.%SERAFIN sensor for "Distance-to-scrap" determination at burner tip in electric arc furnace is developed. The process benefit of this sensor, devoted to the monitoring of the melting scraps, will be discussed. Meanwhile, its principle of measurement and the design feature of optical head are described in detail. SERAFIN sensor is an on-line "distance-to-scrap" measurement technique which is fitted inside annular burners, combined burners or oxygen lances. Industrial experiment shows that this sensor could be used to monitor the melting of scrap in front of each injector, and thus optimising its operation and detecting blow-back occurrences before any damage is created. The comparison made with the panel overheating proves their ability to predict blow-back proclivity.

  6. 响应面法优化电炉炼钢粉尘中Zn的选择性浸出%Optimization of selective leaching of Zn from electric arc furnace steelmaking dust using response surface methodology

    Institute of Scientific and Technical Information of China (English)

    Mehmet KUL; Kürşad Oğuz OSKAY; MehmetŞİMŞİR; Halit SÜBÜTAY; Habip KIRGEZEN

    2015-01-01

    The aim of this work is to investigate and optimize the effects of the leaching parameters on the selective leaching of zinc from electric arc furnace steelmaking dust (EAFD). The response surface method was applied on the basis of a three-level Box–Behnken experimental design method for optimization of selective leaching parameters of zinc from EAFD. The leaching recoveries of zinc (YZn) and iron (YFe) were taken as the response variables, where the concentration of sulphuric acid (X1, mol/L), leaching temperature (X2, °C), leaching time (X3, min), and liquid/solid ratio (X4, mL/g) were considered as the independent variables (factors). The mathematical model was proposed. Statistical ANOVA analysis and confirmation tests were applied. A maximum of 79.09% of zinc was recovered while the minimum iron recovery was 4.08% under the optimum conditions of leaching time 56.42 min, H2SO4 concentration 2.35 mol/L, leaching temperature 25 °C and liquid/solid ratios. By using ANOVA, the most influential factors on leaching of zinc and iron were determined as H2SO4 concentration and leaching temperature, respectively. The proposed model equations using response surface methodology show good agreement with the experimental data, with correlation coefficients (R2) of 0.98 for zinc recovery and 0.97 for iron recovery.%研究浸出参数对电炉炼钢粉尘灰中选择浸出性Zn的影响,以Zn和Fe的浸出率为响应变量,以硫酸浓度、浸出温度、浸出时间和液固比为独立变量,采用基于三水平Box−Behnken的响应面法对浸出参数进行优化。对试验结果进行ANOVA分析和验证。在硫酸浓度为2.35 mol/L,浸出温度为25℃,浸出时间为56.42 min,液固比为5的条件下,可得到Zn的最大浸出率为79.09%, Fe的最小浸出率为4.08%。通过ANOVA分析表明,对Zn和Fe浸出率影响最大的因素为硫酸浓度和浸出温度。基于响应面法的模型与试验数据具有很好的一致性,Zn和Fe

  7. Ratio of Anthracite to Ilmenite of Titanium Slag Smelted by 30 MVA DC Arc Furnace%30MVA直流电弧炉冶炼钛渣配碳比研究

    Institute of Scientific and Technical Information of China (English)

    韩丰霞; 雷霆; 周林; 黄世弘; 吕改改

    2012-01-01

    工业生产中,为生产出合格的钛渣必须加入适量的碳作为还原剂,将高价氧化物还原为低价氧化物.云南某公司30 MVA大型密闭直漉电弧炉(DC炉)生产运行过程中,通过控制无烟煤用量与钛精矿用量之比——配碳比(ratio of anthracite to ilmenite,简称AIR),使生产在输入能量一定、钛精矿成分稳定的条件下力求获得良好的产品品质.生产通过中空石墨电极将钛精矿和无烟煤加入DC炉内,熔炼温度控制为1973 ~2023 K;熔炼输入功率为15 MVA;入炉钛精矿粒度为0.1~0.33 mm;入炉无烟煤粒径为5~25mm的比例大于85%.理论上熔炼还原1t钛精矿,将会产出526 kg渣和368 kg金属铁,O/I比率约为89.4%,理论配碳比约为7.895%.通过生产物料衡算得出,一定熔炼周期内的AIR平均值为12.228%,O/I比率平均值为81.317%.在配碳量不足的情况下,钛精矿中的FeO易于离解出氧并与碳结合,使FeO还原反应优先于TiO2等氧化物,碳最大可能的消耗在FeO的还原上;配碳量越高,则碳将用于还原难还原的氧化物(如MgO,CaO),MnO等)上,使FeO的还原受到抑制.配碳比还会影响DC电炉熔渣流动性和挂渣层.试生产熔炼周期内,通过调整AIR,实现了钛渣中TiO2品质的提高,其含量可从82%提高到89%以上.%Hie adequate carbon should be fed as reductant in order to achieve qualified titanium slag, and deoxidized the highoxide to lowoxide. The domestic first 30 MVA DC arc furnace of a company in Yunnan province obtained the favorable slag by controlling the ratio of anthracite to ilmenite (AIR) , in the case of certain energy input and stable component of ilmenite. The ilmenite and anthracite were put into DC furnace through hollow graphite electrode, meanwhile it was needed to control temperature between 1973 K and 2023 K, IS MVA of input power, 0. 1 ~0. 33 mm of partical size of ilmenite, the ratio of anthracite partical size range of 5 ~ 25 mm were more

  8. Feasibility study of utilizing solar furnace technology in steel making industry

    Energy Technology Data Exchange (ETDEWEB)

    Abbaspoursani, K. [The Faculty of Mechanical Engineering, Takestan Islamic Azad University (Iran, Islamic Republic of)], Email: a.abbaspour@tiau.ac.ir; Tofigh, A.A.; Nahang Toudeshki, S.; Hadadian, A. [Department of Energy, Materials and Energy Research Center (Iran, Islamic Republic of)], Email: Ali.A.Tofigh@gmail.com, email: toudeshki@hotmail.com, email: Arash.Hadadian@gmail.com; Farahmandpour, B. [Iranian Fuel Conservation company (Iran, Islamic Republic of)], Email: farahmandpour@gmail.com

    2011-07-01

    In Iran, the casting industry consumes 33.6% of electricity production, and most of this electricity is used in the melting process. Currently, scrap preheating is done using electric arc furnaces and the aim of this study is to assess the feasibility of replacing electric arc furnaces with solar furnaces. The performance of solar furnaces in the Iran Alloy Steel Company under Yazd climate conditions was studied. It was found that the solar irradiation time and solar insulation are sufficient to operate a solar furnace with the capacity to preheat 250 thousand tons per year of scrap to 500 degrees celsius. Results showed that such a furnace would decrease energy consumption by 40 GWh per year and that it would take 5 years to return the investment. This study demonstrated that operating a solar furnace in the Iran Alloy Steel Company under Yazd climate conditions is feasible and would result in economic and environmental benefits.

  9. High temperature solar furnace: current applications and future potential

    Energy Technology Data Exchange (ETDEWEB)

    Bjorndalen, N. [Dalhousie Univ., Faculty of Engineering, Halifax, NS (Canada)

    2003-02-15

    The high temperature solar furnace can offer great opportunities for the production of many types of products worldwide, but recent advances in this technology have been limited to metal reduction. The production of semiconductors, which are utilized to a great extent in the electronic industry, is a viable option for this technology that has been overlooked. Especially where sand and sunlight are plentiful (countries that surround the equator), silicon chips produced with a solar furnace can have great economical value. This paper describes current and potential solar furnace technologies. The components of the solar furnace are described, as well as metal reduction processes including zinc and aluminum production. The viability of silicon chip production is also examined. The possibilities for other product development using an extremely (up to 10,000 deg C) high temperature solar furnace are also discussed. Economically, the benefits of solar furnaces are great, with only high initial start-up costs and little operation costs. Metal reduction processes can also be enhanced with high temperature solar furnaces in that plugging problems are eliminated. By replacing conventional furnaces, such as blast and electric arc furnaces, with a high temperature solar furnace, CO{sub 2} emissions and energy consumption can be greatly reduced, which will bring in added dividends to the society. (Author)

  10. [The electric furnace of Henri Moissan at one hundred years: connection with the electric furnace, the solar furnace, the plasma furnace?].

    Science.gov (United States)

    Royère, C

    1999-03-01

    The trace of Henri Moissan's pioneer work 100 years ago is clearly evidenced by an overview of achievements in high temperature devices; 1987: "Le four électrique" by Henri Moissan; 1948-1952: "High temperature heating in a cavity rotary kiln using focusing of solar radiation" by Félix Trombe; 1962: "The cavity rotary kiln using focused solar radiation jointly with a plasma gun" by Marc Foëx; 1970: "The rotary kiln with two plasma guns and arc transfer" by Marc Foëx; 1984: "The plasma furnace" by Electricité de France (EDF) at Renardières; 1997: "The plasma furnace" by the Atomic Energy Center (CEA) at Cadarache, the VULCANO program. The first part of this contribution is devoted to Henri Moissan. Re-reading his early book on the electric furnace, especially the first chapter and the sections on silica, carbon vapor and experiments performed in casting molten metal--the conclusions are outstanding--provides modern readers with an amazing insight into future developments. The last two parts are devoted to Félix Trombe and Marc Foëx, tracing the evolution of high temperature cavity processus leading to the solar furnace and the present day plasma furnace at the CEA. Focus is placed on research conducted by the French National Center for Scientific Research (CNRS) with the solar and plasma furnaces at Odeillo. The relationships with Henri Moissan's early work are amazing, offering a well deserved homage to this pioneer researcher.

  11. Paired Straight Hearth Furnace - Transformational Ironmaking Process

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wei-Kao [McMaster Univ., Hamilton, ON (Canada); Debski, Paul [Andritz Metals Inc.,Canonsburg, PA (United States)

    2014-11-19

    The U. S. steel industry has reduced its energy intensity per ton of steel shipped by 33% since 1990. However, further significant gains in energy efficiency will require the development of new, transformational iron and steelmaking processes. The Paired Straight Hearth Furnace (PSH) process is an emerging alternative high productivity, direct reduced iron (DRI) technology that may achieve very low fuel rates and has the potential to replace blast furnace ironmaking. The PSH furnace can operate independently or may be coupled with other melting technologies to produce liquid hot metal that is both similar to blast furnace iron and suitable as a feedstock for basic oxygen steelmaking furnaces. The PSH process uses non-metallurgical coal as a reductant to convert iron oxides such as iron ore and steelmaking by-product oxides to DRI pellets. In this process, a multi-layer, nominally 120mm tall bed of composite “green balls” made from oxide, coal and binder is built up and contained within a moving refractory hearth. The pellet bed absorbs radiant heat energy during exposure to the high temperature interior refractory surfaces of the PSH while generating a strongly reducing gas atmosphere in the bed that yields a highly metalized DRI product. The PSH concept has been well tested in static hearth experiments. A moving bed design is being developed. The process developers believe that if successful, the PSH process has the potential to replace blast furnaces and coke ovens at a fraction of the operating and capital cost while using about 30% less energy relative to current blast furnace technology. DRI output could also feed electric arc furnaces (EAFs) by displacing a portion of the scrap charge.

  12. Heat treatment furnace

    Science.gov (United States)

    Seals, Roland D; Parrott, Jeffrey G; DeMint, Paul D; Finney, Kevin R; Blue, Charles T

    2014-10-21

    A furnace heats through both infrared radiation and convective air utilizing an infrared/purge gas design that enables improved temperature control to enable more uniform treatment of workpieces. The furnace utilizes lamps, the electrical end connections of which are located in an enclosure outside the furnace chamber, with the lamps extending into the furnace chamber through openings in the wall of the chamber. The enclosure is purged with gas, which gas flows from the enclosure into the furnace chamber via the openings in the wall of the chamber so that the gas flows above and around the lamps and is heated to form a convective mechanism in heating parts.

  13. Electric Arc Furnace as a Source of Emission of Polychlorinated Dibenzo-p-Dioxins and Polychlorinated Dibenzofurans in Perspective of the Council Directive 96/61 EC Concerning Integrated Pollution Prevention and Control

    Directory of Open Access Journals (Sweden)

    Sofilić, T.

    2008-01-01

    daily care for environmental protection and preservation. This Directive integrates control of emissions and overall impact of industrial installations on the environment, meaning recognition of the entire impact from particular industrial processes on the environment (air, water, soil, waste, noise, use of raw materials, energy efficiency, prevention of accidents, etc.. The IPPC Directive has introduced a system of authorization (environmental permit that needs to be obtained in order to perform business activities and run processes using the best available techniques (BAT.Taking into account the harmful impact of PCDDs/Fs on the environment, and their unavoidability in metallurgical processes, a series of methods has been developed for their partial prevention or at least reduction of their concentration in smoke gas discharge, and thus prevent environmental pollution through these very harmful compounds. In order to prevent the occurrence of PCDDs/Fs metallurgical processes often use methods based on the principle of selective catalyst reduction. For removal of the already generated PCDDs/Fs from waste gases methods of thermal decomposition at high temperatures or various sorption, i. e. "dry" and "wet" cleaning techniques are used.As the implementation of the IPPC Directive is a complex procedure requiring highly educated experts, significant investments into production processes and their modernization, or sometimeseven replacement, steel shops need to timely prepare themselves for the obligations in order to harmonize the existing regulation with the requirements of the IPPC Directive.The requirements of the Directive have to be studied thoroughly. The required steps have to be carefully thought through, previously identifying the cost and time frame necessary to bring the existing electric arc furnace (EAF steel production processes into conformance with the requirements of the IPPC Directive.The paper discusses the requirements of the IPPC Directive that are

  14. Corrosion mechanism of MgO-C and MgO-C-Al refractories used in stainless steel electric arc furnace; Mecanismo de corrosion a refractarios de MgO-C y MgO-C-Al en horno electrico

    Energy Technology Data Exchange (ETDEWEB)

    Pena, P.; Aza, A. H. de; Contreras, L.; Garcia-Crrodeguas, R.; Aza, S. de; Almagro, J. F.; Luna, C.; Guerrero Barranco, M.; Ferrer, F. J.

    2010-07-01

    This article presents the results of a post-mortem study of various MgO-C and MgO-C-Al pieces that are used in the electric furnaces at the Acerinox factory in Cadiz. From the chemical, thermal, mineralogical and microstructural characterization of the materials prior to use and post-mortem it has been established that, in both types of refractories, the corrosion has lead to the formation of reaction layers with different chemical and mineralogical composition, as a function of temperature and oxygen partial pressure, ranging from the hot to the cold face and strongly depending on the zone of the electric furnace where the piece is situated. Changes in graphite content have been observed in both types of materials by X-ray diffraction. These changes have been quantified by Differential Thermal Analysis. In MgO-C-Al refractories it has been observed the formation of small amounts of C{sub 3}Al{sub 4} inside the pieces and MgAl{sub 2}O{sub 4} in the refractories hot face. Keeping in mind the obtained results and the phase equilibrium diagram of Mg-C-Al-O it has been established a corrosion mechanism for both types of materials. It cannot be established by the present results that additions of Al ({approx}{approx} 2 % in weight) improve the performance of MgO-C materials. (Author)

  15. Ladle furnace application at Companhia Siderurgica Belgo-Mineira LD steel industry; Aplicacao de forno panela na aciaria LD da CSBM

    Energy Technology Data Exchange (ETDEWEB)

    Paes, Jose E.; Magalhaes, Jorge L. de; Batista, Julio B. [Companhia Siderurgica Belgo-Mineira (CSBM), Joao Monlevade, MG (Brazil)

    1989-12-31

    The ladle furnace is often used in steel plants with electric arc furnaces. CSBM introduces this important metallurgical process in its new steel plant. In this paper, the results obtained with the ladle furnace are shown, with special emphasis in a better control of the operational variables and the productivity and quality gains which result from such process.9 figs., 3 tabs

  16. A comparative study of modelling AC electric arc by one-dimensional interpolation for power system harmonics analysis

    OpenAIRE

    Liu Yu-Jen; Hung Jen-Pan; Chen Shang-I; Lin Cheng-Wei

    2016-01-01

    Electric arc is a discharge phenomenon caused by particular electrical events and arc produced facilities in power system, for example the occurrence of short-circuit fault in feeders and the use of electric arc furnace for steel-making. All of these electric arcs have a highly nonlinear nature and can be considered as a significant source of power quality problems. To investigate the impacts of the electric arcs on power quality studies the development of the electric arc models for simulati...

  17. Furnace bottom rise mechanism in preparation of Al-Si alloys by electrothermal process

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The experiments of preparation of Al-Si alloys by electrothermal process were carried out respectively in 20 kW, 100 kW and 1 800 kW DC arc furnaces. The mechanism of furnace bottom rise was studied.It was found that the bottom rise can be divided into three types, including the low bottom temperature, abnormal reducing reaction and carbide deposition. The furnace bottom rise is related to the carbon ratio of the briquet, the heating speed of the briquet and the parameters and operation of furnace.

  18. Refractory Corrosion Mechanisms in a Novel High Carbon Ferromanganese Production Furnace

    Science.gov (United States)

    Gregurek, D.; Wenzl, C.; Kreuzer, D.; Spanring, A.; Kirschen, M.; Zeelie, D.; Groenewald, J.

    2016-12-01

    The present paper presents the refractory design for a novel HCFeMn smelting furnace that, other than standard submerged arc furnaces, allows the processing of fine ores. A combination of basic and non-basic materials, comprising bricks, castables and ramming was chosen, under consideration of the unique furnace design and process conditions. Post-mortem investigations on refractory samples from the different furnace zones were carried out and provided information about the main wear mechanism. Additionally, investigations of the process slag and metal were carried out both practically and theoretically using thermodynamic calculations, to better understand the corrosion phenomena observed in the post mortem samples.

  19. Refractory Corrosion Mechanisms in a Novel High Carbon Ferromanganese Production Furnace

    Science.gov (United States)

    Gregurek, D.; Wenzl, C.; Kreuzer, D.; Spanring, A.; Kirschen, M.; Zeelie, D.; Groenewald, J.

    2016-09-01

    The present paper presents the refractory design for a novel HCFeMn smelting furnace that, other than standard submerged arc furnaces, allows the processing of fine ores. A combination of basic and non-basic materials, comprising bricks, castables and ramming was chosen, under consideration of the unique furnace design and process conditions. Post-mortem investigations on refractory samples from the different furnace zones were carried out and provided information about the main wear mechanism. Additionally, investigations of the process slag and metal were carried out both practically and theoretically using thermodynamic calculations, to better understand the corrosion phenomena observed in the post mortem samples.

  20. Driven Motion and Instability of an Atmospheric Pressure Arc

    Energy Technology Data Exchange (ETDEWEB)

    Max Karasik

    1999-12-01

    Atmospheric pressure arcs are used extensively in applications such as welding and metallurgy. However, comparatively little is known of the physics of such arcs in external magnetic fields and the mechanisms of the instabilities present. In order to address questions of equilibrium and stability of such arcs, an experimental arc furnace is constructed and operated in air with graphite cathode and steel anode at currents 100-250 A. The arc is diagnosed with a gated intensified camera and a collimated photodiode array, as well as fast voltage and current probes.

  1. Cathodic arcs

    Energy Technology Data Exchange (ETDEWEB)

    Anders, Andre

    2003-10-29

    Cathodic arc plasma deposition has become the technology of choice for hard, wear and corrosion resistant coatings for a variety of applications. The history, basic physics of cathodic arc operation, the infamous macroparticle problem and common filter solutions, and emerging high-tech applications are briefly reviewed. Cathodic arc plasmas standout due to their high degree of ionization, with important consequences for film nucleation, growth, and efficient utilization of substrate bias. Industrial processes often use cathodic arc plasma in reactive mode. In contrast, the science of arcs has focused on the case of vacuum arcs. Future research directions include closing the knowledge gap for reactive mode, large area coating, linear sources and filters, metal plasma immersion process, with application in high-tech and biomedical fields.

  2. Cathodic arcs

    OpenAIRE

    Anders, Andre

    2003-01-01

    Cathodic arc plasma deposition has become the technology of choice for hard, wear and corrosion resistant coatings for a variety of applications. The history, basic physics of cathodic arc operation, the infamous macroparticle problem and common filter solutions, and emerging high-tech applications are briefly reviewed. Cathodic arc plasmas stand out due to their high degree of ionization, with important consequences for film nucleation, growth, and efficient utilization of substrate bia...

  3. Numerical modeling of transferred arc melting bath heating; Modelisation numerique du chauffage de bains par arc transfere

    Energy Technology Data Exchange (ETDEWEB)

    Bouvier, A. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches; Trenty, L.; Guillot, J.B. [Ecole Centrale de Paris, Laboratoire EM2C. CNRS, 92 - Chatenay-Malabry (France); Delalondre, C. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches

    1997-12-31

    This paper presents the modeling of a transferred electric arc inside a bath of melted metal. After a recall of the context of the study, the problem of the modeling, which involves magnetohydrodynamic coupling inside the arc and the bath, is described. The equations that govern the phenomena inside the arc and the bath are recalled and the approach used for the modeling of the anode region of the arc is explained using a 1-D sub-model. The conditions of connection between arc and bath calculations are explained and calculation results obtained with a 200 kW laboratory furnace geometry are presented. (J.S.) 8 refs.

  4. Calculations in furnace technology

    CERN Document Server

    Davies, Clive; Hopkins, DW; Owen, WS

    2013-01-01

    Calculations in Furnace Technology presents the theoretical and practical aspects of furnace technology. This book provides information pertinent to the development, application, and efficiency of furnace technology. Organized into eight chapters, this book begins with an overview of the exothermic reactions that occur when carbon, hydrogen, and sulfur are burned to release the energy available in the fuel. This text then evaluates the efficiencies to measure the quantity of fuel used, of flue gases leaving the plant, of air entering, and the heat lost to the surroundings. Other chapters consi

  5. Extraction of Zinc from Electric Arc Furnace Dust by Alkaline Leaching Followed by Fusion of the Leaching Residue with Caustic Soda%氢氧化钠浸取-浸取渣熔融法从炼钢厂烟尘中提取锌的研究

    Institute of Scientific and Technical Information of China (English)

    赵由才; R. Stanforth

    2004-01-01

    Extractability of zinc from two types of electric arc furnace (EAF) dusts containing 24.8% and 16.8%of zinc respectively (denoted as Sample A and Sample B) were tested using direct alkaline leaching followed by fusion of the resulting leaching residues with caustic soda. The experimental results show that the extraction of zinc is heavily dependent on the contents of iron in the dusts. The higher iron content, the lower extraction of zinc is obtained. 53% and 38% of zinc can be extracted when both dusts were directly contacted with 5 mol. L-1 NaOH solution for 42 h. The remaining zinc left in the leaching residues, which supposed to be present as zinc ferrites, can be further leached when the residues were fused with caustic soda. Quantitative extraction of zinc can be obtained from the leaching residue of Sample A while only 85% from Sample B. The extractability of zinc from dusts with various contents of iron is compared. The production flowsheet for zinc from the dusts using the process proposed is discussed.

  6. ENERGY STAR Certified Furnaces

    Data.gov (United States)

    U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 4.0 ENERGY STAR Program Requirements for Furnaces that are effective as of February 1,...

  7. Regularities of heat transfer in the gas layers of a steam boiler furnace flame. Part II. Gas layer radiation laws and the procedure for calculating heat transfer in furnaces, fire boxes, and combustion chambers developed on the basis of these laws

    Science.gov (United States)

    Makarov, A. N.

    2014-10-01

    The article presents the results stemming from the scientific discovery of laws relating to radiation from the gas layers generated during flame combustion of fuel and when electric arc burns in electric-arc steel-melting furnaces. The procedure for calculating heat transfer in electric-arc and torch furnaces, fire-boxes, and combustion chambers elaborated on the basis of this discovery is described.

  8. Arc Statistics

    CERN Document Server

    Meneghetti, M; Dahle, H; Limousin, M

    2013-01-01

    The existence of an arc statistics problem was at the center of a strong debate in the last fifteen years. With the aim to clarify if the optical depth for giant gravitational arcs by galaxy clusters in the so called concordance model is compatible with observations, several studies were carried out which helped to significantly improve our knowledge of strong lensing clusters, unveiling their extremely complex internal structure. In particular, the abundance and the frequency of strong lensing events like gravitational arcs turned out to be a potentially very powerful tool to trace the structure formation. However, given the limited size of observational and theoretical data-sets, the power of arc statistics as a cosmological tool has been only minimally exploited so far. On the other hand, the last years were characterized by significant advancements in the field, and several cluster surveys that are ongoing or planned for the near future seem to have the potential to make arc statistics a competitive cosmo...

  9. Variations in the constant component of the phase voltage in ore-smelting furnaces for the production of phosphorus and calcium carbide

    Science.gov (United States)

    Pedro, A. A.; Arlievskii, M. P.

    2009-12-01

    Phosphorus and carbide furnaces are considered as an example to study the character of changes in and the nature of constant component U cc in the phase voltage of an ore-smelting furnace with a closed furnace top. The value and polarity of U cc depend on the relation between the chemical interaction of an electrode with the reaction-zone components and the degree of development and the conditions of an electric arc.

  10. Cupola Furnace Computer Process Model

    Energy Technology Data Exchange (ETDEWEB)

    Seymour Katz

    2004-12-31

    The cupola furnace generates more than 50% of the liquid iron used to produce the 9+ million tons of castings annually. The cupola converts iron and steel into cast iron. The main advantages of the cupola furnace are lower energy costs than those of competing furnaces (electric) and the ability to melt less expensive metallic scrap than the competing furnaces. However the chemical and physical processes that take place in the cupola furnace are highly complex making it difficult to operate the furnace in optimal fashion. The results are low energy efficiency and poor recovery of important and expensive alloy elements due to oxidation. Between 1990 and 2004 under the auspices of the Department of Energy, the American Foundry Society and General Motors Corp. a computer simulation of the cupola furnace was developed that accurately describes the complex behavior of the furnace. When provided with the furnace input conditions the model provides accurate values of the output conditions in a matter of seconds. It also provides key diagnostics. Using clues from the diagnostics a trained specialist can infer changes in the operation that will move the system toward higher efficiency. Repeating the process in an iterative fashion leads to near optimum operating conditions with just a few iterations. More advanced uses of the program have been examined. The program is currently being combined with an ''Expert System'' to permit optimization in real time. The program has been combined with ''neural network'' programs to affect very easy scanning of a wide range of furnace operation. Rudimentary efforts were successfully made to operate the furnace using a computer. References to these more advanced systems will be found in the ''Cupola Handbook''. Chapter 27, American Foundry Society, Des Plaines, IL (1999).

  11. TECHNOLOGY DEMONSTRATION SUMMARY. BABCOCK AND WILCOX CYCLONE FURNACE VITRIFICATION TECHNOLOGY (EPA/540/SR-92/017)

    Science.gov (United States)

    A Superfund Innovative Technology Evaluation (SITE) Demonstration of the Babcock & Wilcox Cyclone Furnace Vitrification Technology was conducted in November 1991. This Demonstration occurred at the Babcock & Wilcox (B&W) Alliance Research Center (ARC) in Alliance, OH. The B&W cyc...

  12. Fabrication of graphene from graphite by a thermal assisted vacuum arc discharge system

    Science.gov (United States)

    Cheng, Guo-Wei; Chu, Kevin; Chen, Jeng Shiung; Tsai, Jeff T. H.

    2017-04-01

    In this study, graphene was fabricated on copper foils using a high temperature furnace embedded in a vacuum arc discharge method. Combining the advantages of chemical vapor deposition and vacuum arc discharge, single-layer graphene can be fabricated at 600 °C base temperature from the mini furnace embedded with a fast heating via the photon radiation from the vacuum arc to 1100 °C on the substrates' surface. The optimal fabrication condition was determined through a series of experiments on ambient pressure, processing time, arc currents, and the cooling process. Observations by scanning electron microscopy, Raman spectroscopy, and optical microscopy showed that the main products were single-layer graphene, which has a uniform thickness across the entire substrate. The results demonstrated that the combination of a vacuum arc with a thermal method that uses graphite as a carbon source provides a low-cost and straight forward method to synthesize graphene films for graphene-based applications.

  13. Arc melter demonstration baseline test results

    Energy Technology Data Exchange (ETDEWEB)

    Soelberg, N.R.; Chambers, A.G.; Anderson, G.L.; Oden, L.L.; O`Connor, W.K.; Turner, P.C.

    1994-07-01

    This report describes the test results and evaluation for the Phase 1 (baseline) arc melter vitrification test series conducted for the Buried Waste Integrated Demonstration program (BWID). Phase 1 tests were conducted on surrogate mixtures of as-incinerated wastes and soil. Some buried wastes, soils, and stored wastes at the INEL and other DOE sites, are contaminated with transuranic (TRU) radionuclides and hazardous organics and metals. The high temperature environment in an electric arc furnace may be used to process these wastes to produce materials suitable for final disposal. An electric arc furnace system can treat heterogeneous wastes and contaminated soils by (a) dissolving and retaining TRU elements and selected toxic metals as oxides in the slag phase, (b) destroying organic materials by dissociation, pyrolyzation, and combustion, and (c) capturing separated volatilized metals in the offgas system for further treatment. Structural metals in the waste may be melted and tapped separately for recycle or disposal, or these metals may be oxidized and dissolved into the slag. The molten slag, after cooling, will provide a glass/ceramic final waste form that is homogeneous, highly nonleachable, and extremely durable. These features make this waste form suitable for immobilization of TRU radionuclides and toxic metals for geologic timeframes. Further, the volume of contaminated wastes and soils will be substantially reduced in the process.

  14. DEVELOPMENT OF ELECTRONIC VERNEUIL FURNACE

    Science.gov (United States)

    HIGH TEMPERATURE, *PLASMA JETS, *REFRACTORY MATERIALS, ALTERNATING CURRENT, CELLULOSE ACETATES, CRYSTAL STRUCTURE, CRYSTALS , GAS DISCHARGES, GROWTH ...PHYSIOLOGY), LABORATORY FURNACES, PLASMAS(PHYSICS), RADIOFREQUENCY GENERATORS, RADIOFREQUENCY POWER, SINGLE CRYSTALS , THEORY.

  15. Gas arc constriction for plasma arc welding

    Science.gov (United States)

    McGee, William F. (Inventor); Rybicki, Daniel J. (Inventor)

    1994-01-01

    A welding torch for plasma arc welding apparatus has an inert gas applied circumferentially about the arc column externally of the constricting nozzle so as to apply a constricting force on the arc after it has exited the nozzle orifice and downstream of the auxiliary shielding gas. The constricting inert gas is supplied to a plenum chamber about the body of the torch and exits through a series of circumferentially disposed orifices in an annular wall forming a closure at the forward end of the constricting gas plenum chamber. The constricting force of the circumferential gas flow about the arc concentrates and focuses the arc column into a more narrow and dense column of energy after exiting the nozzle orifice so that the arc better retains its energy density prior to contacting the workpiece.

  16. Revitalize the US silicon/ferrosilicon industry through energy-efficient technology. Final report, Addendum furnace modeling

    Energy Technology Data Exchange (ETDEWEB)

    Schwsenke, G.K.; Wodley, D.; Szekely, J. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

    1995-07-01

    A project was undertaken to model and analyze the dc submerged plasma arc furnace. A reaction extent model was developed and useful results obtained. The code can be run with commercially hardware and software. Two free energy minimization models were formulated; they may be run by modifying public domain programs.

  17. Waste and dust utilisation in shaft furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Senk, D.; Babich, A.; Gudenau, H.W. [Rhein Westfal TH Aachen, Aachen (Germany)

    2005-07-01

    Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilised e.g. in agglomeration processes (sintering, pelletising or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverised coal (PC) has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

  18. Installation and Trial Run of the Furnace

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In order to meet the demand of neutron experiment in the future, the neutron lab equips with extreme temperature furnace (Fig. 1), the furnace is designed and produced by the professional producer-Scientific

  19. High Efficiency Solar Furnace Core Project

    Data.gov (United States)

    National Aeronautics and Space Administration — It is proposed to develop a high efficiency solar furnace core that greatly lessens the heat losses from the furnace core, either greatly reducing the amount of...

  20. Electrostatic Levitation Furnace for the ISS

    Science.gov (United States)

    Murakami, Keiji; Koshikawa, Naokiyo; Shibasaki, Kohichi; Ishikawa, Takehiko; Okada, Junpei; Takada, Tetsuya; Arai, Tatsuya; Fujino, Naoki; Yamaura, Yukiko

    2012-01-01

    JAXA (Japan Aerospace Exploration Agency) has just started the development of Electrostatic Levitation Furnace to be launched in 2014 for the ISS. This furnace can control the sample position with electrostatic force and heat it above 2000 degree Celsius using semiconductor laser from four different directions. The announcement of Opportunity will be issued soon for this furnace. In this paper, we will show the specifications of this furnace and also the development schedule

  1. Alkaline carbonates in blast furnace process

    Directory of Open Access Journals (Sweden)

    P. Besta

    2014-10-01

    Full Text Available The production of iron in blast furnaces is a complex of physical, chemical and mechanical processes. The input raw materials contain not only metallic components, but also a number of negative elements. The most important negative elements include alkaline carbonates. They can significantly affect the course of the blast furnace process and thus the overall performance of the furnace. As a result of that, it is essential to accurately monitor the alkali content in the blast furnace raw materials. The article analyzes the alkali content in input and output raw materials and their impact on the blast furnace process.

  2. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  3. Welding arc plasma physics

    Science.gov (United States)

    Cain, Bruce L.

    1990-01-01

    The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

  4. Measurement of airflow in residential furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Biermayer, Peter J.; Lutz, James; Lekov, Alex

    2004-01-24

    In order to have a standard for furnaces that includes electricity consumption or for the efficiency of furnace blowers to be determined, it is necessary to determine the airflow of a furnace or furnace blower. This study focused on airflow testing, in order to determine if an existing test method for measuring blower airflow could be used to measure the airflow of a furnace, under conditions seen in actual installations and to collect data and insights into the operating characteristics of various types of furnace blowers, to use in the analysis of the electricity consumption of furnaces. Results of the measured airflow on furnaces with three types of blower and motor combinations are presented in the report. These included: (1) a forward-curved blower wheel with a typical permanent split capacitor (PSC) motor, (2) a forward-curved blower wheel with an electronically-commutated motor (ECM), and (3) a prototype blower, consisting of a backward-inclined blower wheel matched to an ECM motor prototype, which is being developed as an energy-saving alternative to conventional furnace blowers. The testing provided data on power consumption, static and total pressure, and blower speed.

  5. WSTF electrical arc projects

    Science.gov (United States)

    Linley, Larry

    1994-09-01

    The objectives of these projects include the following: validate method used to screen wire insulation with arc tracking characteristics; determine damage resistance to arc as a function of source voltage and insulation thickness; investigate propagation characteristics of Kapton at low voltages; and investigate pyrolytic properties of polyimide insulated (Kapton) wire for low voltage (less than 35 VDC) applications. Supporting diagrams and tables are presented.

  6. Preparation and Arc Breakdown Behavior of Nanocrystalline W-Cu Electrical Contact Materials

    Institute of Scientific and Technical Information of China (English)

    Wenge CHEN; Zhanying KANG; Bingjun DING

    2005-01-01

    Nanostructured (NS) W-Cu composite powder was prepared by mechanical alloying (MA), and nanostructured bulk of W-Cu contact material was fabricated by hot pressed sintering in an electrical vacuum furnace. The microstructure,electric conductivity, hardness, breakdown voltage and arcing time of NS W-Cu alloys were measured and compared to conventional W-Cu alloys prepared by powder metallurgy. The results show that microstructural refinement and uniformity can improve the breakdown behavior, the electric arc stability and the arc extinction ability of nanostructured W-Cu contacts materials. Also, the nanostructured W-Cu contact material shows the characteristic of spreading electric arcs, which is of benefit to electric arc erosion.

  7. Circular-Arc Cartograms

    CERN Document Server

    Kämper, Jan-Hinrich; Nöllenburg, Martin

    2011-01-01

    We present a new circular-arc cartogram model in which countries are drawn with circular arcs instead of straight-line segments. Given a geographic map and values associated with each country in the map, the cartogram is a new map in which the areas of the countries represent the corresponding values. In the circular-arc cartogram model straight-line segments can be replaced with circular arcs in order to achieve the desired areas, while the corners of the polygons defining each country remain fixed. The countries in circular-arc cartograms have the aesthetically pleasing appearance of clouds or snowflakes, depending on whether their edges are bent outwards or inwards. This makes is easy to determine whether a country has grown or shrunk, just by its overall shape. We show that determining whether a given map and area-values can be realized with a circular-arc cartogram is an NP-hard problem. Next we describe a heuristic method for constructing circular-arc cartograms, which uses a max-flow computation on the...

  8. Thermal Imaging Control of Furnaces and Combustors

    Energy Technology Data Exchange (ETDEWEB)

    David M. Rue; Serguei Zelepouga; Ishwar K. Puri

    2003-02-28

    The object if this project is to demonstrate and bring to commercial readiness a near-infrared thermal imaging control system for high temperature furnaces and combustors. The thermal imaging control system, including hardware, signal processing, and control software, is designed to be rugged, self-calibrating, easy to install, and relatively transparent to the furnace operator.

  9. The use of blast furnace slag

    Directory of Open Access Journals (Sweden)

    V. Václavík

    2012-10-01

    Full Text Available The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  10. The use of blast furnace slag

    OpenAIRE

    V. Václavík; V. Dirner; T. Dvorský; J. Daxner

    2012-01-01

    The paper presents the results of experimental research that dealt with the substitution of finely ground blast furnace slag for Portland cement in the course of simple concrete manufacturing. Physical and mechanical properties of experimental concrete mixtures based on finely ground blast furnace slag were observed.

  11. Filtered cathodic arc source

    Science.gov (United States)

    Falabella, Steven; Sanders, David M.

    1994-01-01

    A continuous, cathodic arc ion source coupled to a macro-particle filter capable of separation or elimination of macro-particles from the ion flux produced by cathodic arc discharge. The ion source employs an axial magnetic field on a cathode (target) having tapered sides to confine the arc, thereby providing high target material utilization. A bent magnetic field is used to guide the metal ions from the target to the part to be coated. The macro-particle filter consists of two straight solenoids, end to end, but placed at 45.degree. to one another, which prevents line-of-sight from the arc spot on the target to the parts to be coated, yet provides a path for ions and electrons to flow, and includes a series of baffles for trapping the macro-particles.

  12. Pulsed plasma arc cladding

    Institute of Scientific and Technical Information of China (English)

    龙; 白钢; 李振民; 张赋升; 杨思乾

    2004-01-01

    A prototype of Pulsed Plasma Arc Cladding system was developed, in which single power source supplies both transferred plasma arc (TPA) and non-transferred plasma arc (N-TPA). Both plasmas work in turn in a high frequency controlled by an IGBT connecting nozzle and workpiece. The working frequency of IGBT ranges from 50 ~ 7000Hz, in which the plasmas can work in turn smoothly. Higher than 500 Hz of working frequency is suggested for promotion of cladding quality and protection of IGBT. Drag phenomenon of TPA intensifies as the frequency goes up, which tends to increase the current proportion of TPA and suppress N-TPA. The occupation ratio of IGBT can be regulated from 5% ~ 95%, which balances the power supplies of both plasmas. An occupation ratio higher than 50% gives adequate proportion of arc current for N-TPA to preheat powder.

  13. Cathodic ARC surface cleaning prior to brazing

    Energy Technology Data Exchange (ETDEWEB)

    Dave, V. R. (Vivek R.); Hollis, K. J. (Kendall J.); Castro, R. G. (Richard G.); Smith, F. M. (Frank M.); Javernick, D. A. (Daniel A.)

    2002-01-01

    Surface cleanliness is one the critical process variables in vacuum furnace brazing operations. For a large number of metallic components, cleaning is usually accomplished either by water-based alkali cleaning, but may also involve acid etching or solvent cleaning / rinsing. Nickel plating may also be necessary to ensure proper wetting. All of these cleaning or plating technologies have associated waste disposal issues, and this article explores an alternative cleaning process that generates minimal waste. Cathodic arc, or reserve polarity, is well known for welding of materials with tenacious oxide layers such as aluminum alloys. In this work the reverse polarity effect is used to clean austenitic stainless steel substrates prior to brazing with Ag-28%Cu. This cleaning process is compared to acid pickling and is shown to produce similar wetting behavior as measured by dynamic contact angle experiments. Additionally, dynamic contact angle measurements with water drops are conducted to show that cathodic arc cleaning can remove organic contaminants as well. The process does have its limitations however, and alloys with high titanium and aluminum content such as nickel-based superalloys may still require plating to ensure adequate wetting.

  14. Estimating the Condition of the Heat Resistant Lining in an Electrical Reduction Furnace

    Directory of Open Access Journals (Sweden)

    Jan G. Waalmann

    1988-01-01

    Full Text Available This paper presents a system for estimating the condition of the heat resistant lining in an electrical reduction furnace for ferrosilicon. The system uses temperature measured with thermocouples placed on the outside of the furnace-pot. These measurements are used together with a mathematical model of the temperature distribution in the lining in a recursive least squares algorithm to estimate the position of 'the transformation front'. The system is part of a monitoring system which is being developed in the AIP-project: 'Condition monitoring of strongly exposed process equipment in thc ferroalloy industry'. The estimator runs on-line, and results arc presented in colour-graphics on a display unit. The goal is to locate the transformation front with an accuracy of +- 5cm.

  15. A cylindrical furnace for absorption spectral studies

    Indian Academy of Sciences (India)

    R Venkatasubramanian

    2001-06-01

    A cylindrical furnace with three heating zones, capable of providing a temperature of 1100°C, has been fabricated to enable recording of absorption spectra of high temperature species. The temperature of the furnace can be controlled to ± 1°C of the set temperature. The salient feature of this furnace is that the material being heated can be prevented from depositing on the windows of the absorption cell by maintaining a higher temperature at both the ends of the absorption cell.

  16. FAULT ANALYSIS & TREATMENT OF THE VACUUM CIRCUIT BREAKER ON 66 kV STRAIGHT POWER SUPPLY SUBMERGED ARC FURNACE%66 kV直供电矿热炉用真空断路器的故障分析及处理

    Institute of Scientific and Technical Information of China (English)

    谢红亮

    2016-01-01

    高压真空断路器是利用“真空”(气压为0.01~0.000001 Pa)灭弧的一种断路器,是电力线路中重要的一次控制设备,不仅能通断正常负荷电流,而且还能接通和承受一定时间的短路电流,并能在保护装置作用下自动跳闸,切除短路故障,具有体积小、重量轻、动作快、安全可靠等优点,适用于频繁操作的场所。%High voltage vacuum circuit breaker is a kind of breaker which takes advantage of“vacuum”to cut off arc discharge. It is a kind of important one time controlling device in circuit. It can not only break-make normal current, but also switch on and bear some time short circuit current. In the same time, it can also automatic trip under protective device and cut the short circuit fault. It is suitable for places of operation frequently.

  17. Modeling of Arc Force in Plasma Arc Welding

    Institute of Scientific and Technical Information of China (English)

    GAO Zhonglin; HU Shengsun; YIN Fengliang; WANG Rui

    2008-01-01

    A three. dimensional mathematical model for the transferred-type argon arc was developed to describe arc force on the anode surface. The software ANSYS was employed to solve the model. The model includes a part of torch and tungsten electrode to achieve m ore reasonable results. The arc temperature and flow fields were derived. And the influences of welding parameters on arc force were also studied. The simulated results show that arc pressure at the anode are dependent on the welding current, plasma gas flow rate and electrode neck-in, while not sensitive to arc length.

  18. The induction furnace as a melting facility in steel production. Pt. 1. Features of induction furnaces used in steel production; Der Induktionsofen als Schmelzaggregat fuer die Stahlerzeugung. T. 1. Merkmale von Induktionsoefen in der Stahlerzeugung

    Energy Technology Data Exchange (ETDEWEB)

    Chaabet, Mohamed; Doetsch, Erwin [ABP Induction Systems GmbH, Dortmund (Germany)

    2011-12-15

    Global steel output has now been growing extremely rapidly for a prolonged time; in the past ten years alone, annual production has risen from 851 million t/a (in 2001) to 1417 million t/a (2010), as a result, primarily, of growth in China. Electric steel production using the electric arc furnace as the classical melting facility is around 45 % world-wide, with a rising trend (but excluding the special case of China, where oxygen-route steel holds a 90 % share of production). Following the development of induction technology and inverter outputs of over 40 MW for crucible furnaces with capacities of above 65 t, the induction furnace is now available as an alternative electrical melting installation for use in smaller mini steel mills. The benefits of this technology can be found in high feed-material efficiencies and low environmental and workplace burdens, in addition to the absence of electrode costs and the only modest demands made on the power-supply grid. These features of the induction furnace and their special significance for steel production are examined in Part 1 of this article. The second part of the article then focuses on examples of the use of induction furnaces in the steelmaking plant. (orig.)

  19. Synthesis of aluminium nanoparticles by arc evaporation of an aluminium cathode surface

    Indian Academy of Sciences (India)

    M Gazanfari; M Karimzadeh; S Ghorbani; M R Sadeghi; G Azizi; H Karimi; N Fattahi; Z Karimzadeh

    2014-06-01

    Aluminium nanoparticles (Al Nps) are synthesized using arc discharge method by applying direct current between aluminium electrodes in liquid environment without any use of vacuum equipment, heat exchangers, high temperatures furnaces and inert gases. After synthesis of Al Nps, in situ coating process on the nanoparticles was performed immediately. The effects of media on the yield and morphology of aluminium nanoparticles were investigated. Analysis result of the samples indicated that particle size was less than 30 nm, when 120 A/cm2 arc current was used. In addition, coating agent can affect arc velocity, arc stability, morphology and composition of the nanoparticles. Resultant nanoparticles were identified using X-ray powder diffraction (XRD), also their surface morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and finally the accuracy of coating was assessed with infrared (IR) spectroscopy.

  20. LPCVD Furnace: Tystar Mini Tytan 4600

    Data.gov (United States)

    Federal Laboratory Consortium — Description: CORAL Names: SiN LPCVD, Poly LPCVD, LTO LPCVD This three stack furnace system is utilized to deposit silicon nitride, polysilicon, and low temperature...

  1. A consortium approach to glass furnace modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, S.-L.; Golchert, B.; Petrick, M.

    1999-04-20

    Using computational fluid dynamics to model a glass furnace is a difficult task for any one glass company, laboratory, or university to accomplish. The task of building a computational model of the furnace requires knowledge and experience in modeling two dissimilar regimes (the combustion space and the liquid glass bath), along with the skill necessary to couple these two regimes. Also, a detailed set of experimental data is needed in order to evaluate the output of the code to ensure that the code is providing proper results. Since all these diverse skills are not present in any one research institution, a consortium was formed between Argonne National Laboratory, Purdue University, Mississippi State University, and five glass companies in order to marshal these skills into one three-year program. The objective of this program is to develop a fully coupled, validated simulation of a glass melting furnace that may be used by industry to optimize the performance of existing furnaces.

  2. Modular Distributed Concentrator for Solar Furnace Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This research proposes to develop a lightweight approach to achieving the high concentrations of solar energy needed for a solar furnace achieving temperatures of...

  3. Multiple hearth furnace for reducing iron oxide

    Science.gov (United States)

    Brandon, Mark M [Charlotte, NC; True, Bradford G [Charlotte, NC

    2012-03-13

    A multiple moving hearth furnace (10) having a furnace housing (11) with at least two moving hearths (20) positioned laterally within the furnace housing, the hearths moving in opposite directions and each moving hearth (20) capable of being charged with at least one layer of iron oxide and carbon bearing material at one end, and being capable of discharging reduced material at the other end. A heat insulating partition (92) is positioned between adjacent moving hearths of at least portions of the conversion zones (13), and is capable of communicating gases between the atmospheres of the conversion zones of adjacent moving hearths. A drying/preheat zone (12), a conversion zone (13), and optionally a cooling zone (15) are sequentially positioned along each moving hearth (30) in the furnace housing (11).

  4. Cast construction elements for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    B. Piekarski

    2011-07-01

    Full Text Available The study presents sketches and photos of the cast creep-resistant components used in various types of heat treatment furnaces. The shape of the elements results from the type of the operation carried out in the furnace, while dimensions are adjusted to the size of the furnace working chamber. The castings are mainly made from the high-alloyed, austenitic chromium-nickel or nickel-chromium steel, selecting the grade in accordance with the furnace operating conditions described by the rated temperature, the type and parameters of the applied operating atmosphere, and the charge weight. Typical examples in this family of construction elements are: crucibles, roller tracks, radiant tubes and guides. The majority of castings are produced in sand moulds.

  5. Chamberless residential warm air furnace design

    Energy Technology Data Exchange (ETDEWEB)

    Godfree, J. [Product Design consultant, Pugwash (Canada)

    1996-07-01

    This brief paper is an introduction to the concept of designing residential warm air furnaces without combustion chambers. This is possible since some small burners do not require the thermal support of a combustion chamber to complete the combustion process.

  6. Anhydrous Taphole Mix for Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan

    2010-01-01

    @@ 1 Scope This standard specifies the term,definition,brand,label,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,and quality certificate of anhydrous taphole mix for blast furnace.

  7. Kaolinite Refractory Bricks for Blast Furnaces

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ This standard is suitable to the fireclay bricks for blast furnace. 1 Classification, Shape and Dimension 1 According to physical and chemical indexes, the brick can be divided into two trademarks: ZGN-42 and GN-42.

  8. Magnesia-Chrome Refractories for Flash Furnace

    Institute of Scientific and Technical Information of China (English)

    LI Yong; CHEN Kaixian; LU Xinghua; LIU Jianlong; SUN Jialin; HONG Yanruo

    2002-01-01

    The rapid development of our country's heavy nonferrous metallurgical technology and the revolution in new type of heavynon-ferrous metallurgical furnace have imposed more critical demand on the refractory materials ,i. e. high quality and long service life. This paper presents the domestic status of the refractories for flash furnace , briefly describes the wear of the refractory used , and it is considered that the domestic in refractories for flashfurnace can be surely realized.

  9. Waste and dust utilisation in shaft furnaces

    OpenAIRE

    Senk, D.; Babich, A.; Gudenau, H. W.

    2005-01-01

    Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilized e.g. in agglomeration processes (sintering, pelletizing or briquetting) and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverized coal (PC) has been studied when injecting into shaft furnaces. Following sha...

  10. Arc Plasma Torch Modeling

    CERN Document Server

    Trelles, J P; Vardelle, A; Heberlein, J V R

    2013-01-01

    Arc plasma torches are the primary components of various industrial thermal plasma processes involving plasma spraying, metal cutting and welding, thermal plasma CVD, metal melting and remelting, waste treatment and gas production. They are relatively simple devices whose operation implies intricate thermal, chemical, electrical, and fluid dynamics phenomena. Modeling may be used as a means to better understand the physical processes involved in their operation. This paper presents an overview of the main aspects involved in the modeling of DC arc plasma torches: the mathematical models including thermodynamic and chemical non-equilibrium models, turbulent and radiative transport, thermodynamic and transport property calculation, boundary conditions and arc reattachment models. It focuses on the conventional plasma torches used for plasma spraying that include a hot-cathode and a nozzle anode.

  11. Information modeling system for blast furnace control

    Science.gov (United States)

    Spirin, N. A.; Gileva, L. Y.; Lavrov, V. V.

    2016-09-01

    Modern Iron & Steel Works as a rule are equipped with powerful distributed control systems (DCS) and databases. Implementation of DSC system solves the problem of storage, control, protection, entry, editing and retrieving of information as well as generation of required reporting data. The most advanced and promising approach is to use decision support information technologies based on a complex of mathematical models. The model decision support system for control of blast furnace smelting is designed and operated. The basis of the model system is a complex of mathematical models created using the principle of natural mathematical modeling. This principle provides for construction of mathematical models of two levels. The first level model is a basic state model which makes it possible to assess the vector of system parameters using field data and blast furnace operation results. It is also used to calculate the adjustment (adaptation) coefficients of the predictive block of the system. The second-level model is a predictive model designed to assess the design parameters of the blast furnace process when there are changes in melting conditions relative to its current state. Tasks for which software is developed are described. Characteristics of the main subsystems of the blast furnace process as an object of modeling and control - thermal state of the furnace, blast, gas dynamic and slag conditions of blast furnace smelting - are presented.

  12. Solar Convective Furnace for Metals Processing

    Science.gov (United States)

    Patidar, Deepesh; Tiwari, Sheetanshu; Sharma, Piyush; Pardeshi, Ravindra; Chandra, Laltu; Shekhar, Rajiv

    2015-11-01

    Metals processing operations, primarily soaking, heat treatment, and melting of metals are energy-intensive processes using fossil fuels, either directly or indirectly as electricity, to operate furnaces at high temperatures. Use of concentrated solar energy as a source of heat could be a viable "green" option for industrial heat treatment furnaces. This paper introduces the concept of a solar convective furnace which utilizes hot air generated by an open volumetric air receiver (OVAR)-based solar tower technology. The potential for heating air above 1000°C exists. Air temperatures of 700°C have already been achieved in a 1.5-MWe volumetric air receiver demonstration plant. Efforts to retrofit an industrial aluminium soaking furnace for integration with a solar tower system are briefly described. The design and performance of an OVAR has been discussed. A strategy for designing a 1/15th-scale model of an industrial aluminium soaking furnace has been presented. Preliminary flow and thermal simulation results suggest the presence of recirculating flow in existing furnaces that could possibly result in non-uniform heating of the slabs. The multifarious uses of concentrated solar energy, for example in smelting, metals processing, and even fuel production, should enable it to overcome its cost disadvantage with respect to solar photovoltaics.

  13. Firing temperature accuracy of four dental furnaces.

    Science.gov (United States)

    Haag, Per; Ciber, Edina; Dérand, Tore

    2011-01-01

    In spite of using recommended firing and displayed temperatures, low-fired dental porcelain more often demonstrates unsatisfactory results after firing than porcelain fired at higher temperatures. It could therefore be anticipated that temperatures shown on the display are incorrect, implying that the furnace does not render correct firing programs for low-fired porcelain. The purpose of this study is to investigate deviations from the real temperature during the firing process and also to illustrate the service and maintenance discipline of furnaces at dental laboratories. Totally 20 units of four different types of dental furnaces were selected for testing of temperature accuracy with usage of a digital temperature measurement apparatus, Therma 1. In addition,the staffs at 68 dental laboratories in Sweden were contacted for a telephone interview on furnace brand and on service and maintenance program performed at their laboratories. None of the 20 different dental furnaces in the study could generate the firing temperatures shown on the display, indicating that the hypothesis was correct. Multimat MCII had the least deviation of temperature compared with displayfigures. 62 out of 68 invited dental laboratories chose to participate in the interviews and the result was that very few laboratories had a service and maintenance program living up to quality standards. There is room for improving the precision of dental porcelain furnaces as there are deviations between displayed and read temperatures during the different steps of the firing process.

  14. Volt-ampere characteristics of a nitrogen DC plasma arc with anode melting

    Institute of Scientific and Technical Information of China (English)

    Zhao Peng; Ni Guo-Hua; Meng Yue-Dong; Nagatsu Masaaki

    2013-01-01

    The characteristics of a nitrogen arc using a graphite cathode and a melting anode in a pilot-scale plasma furnace are investigated.The voltage is examined as a function of current and apparent plasma length.The voltage increases non-linearly with the increase of apparent plasma length,with the current fixed.The experimental data so obtained are compared with the predictions of the Bowman model for the electric arc,and with numerical simulations as well.The level of agreement between the experimental data at the melting anode and the numerical predictions confirms the suitability of the proposed the Bowman model.These characteristics are relevant to the engineering design and evaluation of a DC plasma furnace and reactor for the treatment of hazardous fly ash waste.

  15. ARc Welding (Industrial Processing Series).

    Science.gov (United States)

    ARC WELDING , *BIBLIOGRAPHIES), (*ARC WELDS, BIBLIOGRAPHIES), ALUMINUM ALLOYS, TITANIUM ALLOYS, CHROMIUM ALLOYS, METAL PLATES, SPOT WELDING , STEEL...INERT GAS WELDING , MARAGING STEELS, MICROSTRUCTURE, HEAT RESISTANT ALLOYS, HEAT RESISTANT METALS, WELDABILITY, MECHANICAL PROPERTIES, MOLYBDENUM ALLOYS, NICKEL ALLOYS, RESISTANCE WELDING

  16. Arc Heated Scramjet Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Arc Heated Scramjet Test Facility is an arc heated facility which simulates the true enthalpy of flight over the Mach number range of about 4.7 to 8 for free-jet...

  17. Conceptual design and simulation analysis of thermal behaviors of TGR blast furnace and oxygen blast furnace

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Extensive use of carbon based fuel is the main inducement for global warming and more extreme weather.Reducing carbon dioxide emission and enhancing energy use is a common subject in steel industry.In the integrated steel plant,decreasing carbon dioxide emission must consider energy balance in the whole iron and steel works,and secondary energy must be actively utilized.As promising blast-furnaces,top gas recovery blast furnace(TGR-BF) and oxygen blast furnace have been investigated.In this paper,conceptual TGR blast furnace and oxygen blast furnace are proposed.Base on the idea of blast furnace gas de-CO2 circulating as reducing agent and the idea of pure oxygen blast decreasing the thermal reserve zone temperature,process modeling is conducted with ASPEN Plus.It is shown that the developed model reasonably describes the energy balance and mass balance feature of the furnace,and provides basic thermodynamic condition for furnaces.The effects of changes in different operation conditions are studied by sensitivity analysis and reference data from simulation.

  18. ALICE-ARC integration

    DEFF Research Database (Denmark)

    Anderlik, Csaba; Gregersen, Anders Rhod; Kleist, Josva;

    2008-01-01

    Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructure, using the client tools available in AliEn. The interoperation has two aspects, one is the data...

  19. Thermal Arc Spray Overview

    Science.gov (United States)

    Hafiz Abd Malek, Muhamad; Hayati Saad, Nor; Kiyai Abas, Sunhaji; Mohd Shah, Noriyati

    2013-06-01

    Usage of protective coating for corrosion protection was on highly demand during the past decade; and thermal spray coating played a major part during that time. In recent years, the thermal arc spray coating becomes a popular coating. Many big players in oil and gas such as PETRONAS, EXXON MOBIL and SHELL in Malaysia tend to use the coating on steel structure as a corrosion protection. Further developments in coating processes, the devices, and raw materials have led to expansion of functional coatings and applications scope from conventional coating to specialized industries. It is widely used because of its ability to withstand high process temperature, offer advantages in efficiency, lower cost and acts as a corrosion protection. Previous research also indicated that the thermal arc spray offers better coating properties compared to other methods of spray. This paper reviews some critical area of thermal spray coating by discussing the process/parameter of thermal arc spray technology and quality control of coating. Coating performance against corrosion, wear and special characteristic of coating are also described. The field application of arc spray technology are demonstrated and reviewed.

  20. Variable polarity arc welding

    Science.gov (United States)

    Bayless, E. O., Jr.

    1991-01-01

    Technological advances generate within themselves dissatisfactions that lead to further advances in a process. A series of advances in welding technology which culminated in the Variable Polarity Plasma Arc (VPPA) Welding Process and an advance instituted to overcome the latest dissatisfactions with the process: automated VPPA welding are described briefly.

  1. Gas tungsten arc welder

    Science.gov (United States)

    Christiansen, D.W.; Brown, W.F.

    A welder for automated closure of fuel pins by a gas tungsten arc process in which a rotating length of cladding is positioned adjacent a welding electrode in a sealed enclosure. An independently movable axial grinder is provided in the enclosure for refurbishing the used electrode between welds.

  2. Motion of polar cap arcs

    Science.gov (United States)

    Hosokawa, K.; Moen, J. I.; Shiokawa, K.; Otsuka, Y.

    2011-01-01

    A statistics of motion of polar cap arcs is conducted by using 5 years of optical data from an all-sky imager at Resolute Bay, Canada (74.73°N, 265.07°E). We identified 743 arcs by using an automated arc detection algorithm and statistically examined their moving velocities as estimated by the method of Hosokawa et al. (2006). The number of the arcs studied is about 5 times larger than that in the previous statistics of polar cap arcs by Valladares et al. (1994); thus, we could expect to obtain more statistically significant results. Polar cap arcs are found to fall into two distinct categories: the By-dependent and By-independent arcs. The motion of the former arcs follows the rule reported by Valladares et al. (1994), who showed that stable polar cap arcs move in the direction of the interplanetary magnetic field (IMF) By. About two thirds of the arcs during northward IMF conditions belong to this category. The latter arcs always move poleward irrespective of the sign of the IMF By, which possibly correspond to the poleward moving arcs in the morning side reported by Shiokawa et al. (1997). At least one third of the arcs belong to this category. The By-dependent arcs tend to move faster when the magnitude of the IMF By is larger, suggesting that the transport of open flux by lobe reconnection from one polar cap compartment to the other controls their motion. In contrast, the speed of the By-independent arcs does not correlate with the magnitude of the By. The motions of both the By-dependent and By-independent arcs are most probably caused by the magnetospheric convection. Convection in the region of By-dependent arcs is affected by the IMF By, which indicates that their sources may be on open field lines or in the closed magnetosphere adjacent to the open-closed boundary, whereas By-independent arcs seem to be well on closed field lines. Hence, the magnetospheric source of the two types of arc may be different. This implies that the mechanisms causing the

  3. Computational simulations and experimental validation of a furnace brazing process

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Gianoulakis, S.E.; Malizia, L.A.

    1998-12-31

    Modeling of a furnace brazing process is described. The computational tools predict the thermal response of loaded hardware in a hydrogen brazing furnace to programmed furnace profiles. Experiments were conducted to validate the model and resolve computational uncertainties. Critical boundary conditions that affect materials and processing response to the furnace environment were determined. {open_quotes}Global{close_quotes} and local issues (i.e., at the furnace/hardware and joint levels, respectively) are discussed. The ability to accurately simulate and control furnace conditions is examined.

  4. Industrial and process furnaces principles, design and operation

    CERN Document Server

    Jenkins, Barrie

    2014-01-01

    Furnaces sit at the core of all branches of manufacture and industry, so it is vital that these are designed and operated safely and effi-ciently. This reference provides all of the furnace theory needed to ensure that this can be executed successfully on an industrial scale. Industrial and Process Furnaces: Principles, 2nd Edition provides comprehensive coverage of all aspects of furnace operation and design, including topics essential for process engineers and operators to better understand furnaces. This includes: the combustion process and its control, furnace fuels, efficiency,

  5. Carbon monoxide exposure in blast furnace workers.

    Science.gov (United States)

    Lewis, S; Mason, C; Srna, J

    1992-09-01

    This study investigated the occupational exposure to carbon monoxide (CO) of a group of blast furnace workers from an integrated steelworks, compared to a control group having no significant occupational CO exposure from other areas in the same works. The study was undertaken in 1984 at Port Kembla, New South Wales. Carboxyhaemoglobin (COHb) levels before and after an eight-hour work shift were measured in 98 male steelworkers: 52 from two CO-exposed iron blast furnaces and 46 controls from production areas in the same steelworks. The sample was stratified by smoking habits. Environmental air CO levels had been found to be consistently higher on one furnace than on the other. Absorption of CO from the working environment occurred in workers on the blast furnace with higher CO levels, regardless of smoking habits. On this blast furnace, some readings of COHb levels after a workshift in nonsmokers approached the proposed Australian occupational limit of 5 per cent COHb saturation. Overall, workers with the highest occupational exposure who smoked most heavily had the highest absorption of CO over a work shift. Biological monitoring gives an accurate measure of individual worker 'dose' of CO from all sources. Both environmental monitoring and biological monitoring need to be included as part of a program for controlling occupational CO exposure.

  6. Use of solar furnaces. II - Thermophysical properties

    Science.gov (United States)

    Suresh, D.; Charters, W. W. S.; Rohatgi, P. K.

    1982-01-01

    The various ways in which solar furnaces have been used to measure the high-temperature thermophysical properties of materials are reviewed, with attention given to the advantages and disadvantages of these furnaces. Thermal expansion experiments are seen as lacking accuracy. By introducing homogeneous heating methods, as well as precision dilatometers, this defect could be overcome. Solar furnaces must be designed so as to give larger focal areas of uniform flux density. Modifying the pulsed method so as to eliminate the requirement for homogeneity of the energy flux is thought desirable. It would also be worthwhile to design a suitable loading device to obviate complications arising out of elongation of the specimen during tests.

  7. Software sensor for slab reheating furnace

    Institute of Scientific and Technical Information of China (English)

    Zhihua Xiong; Guohong Huang; Huihe Shao

    2005-01-01

    It has long been thought that a reheating furnace, with its inherent measurement difficulties and complex dynamics, posed almost insurmountable problems to engineers in steel plants. A novel software sensor is proposed to make more effective use of those measurements that are already available, which has great importance both to slab quality and energy saving. The proposed method is based on the mixtures of Gaussian processes (GP) with the expectation maximization (EM) algorithm employed for parameter estimation of the mixture of models. The mixture model can alleviate the computational complexity of GP and also accords with the changes of operating condition in practical processes. It is demonstrated by on-line estimation of the furnace gas temperature in 1580 reheating furnace in Baosteel Corporation (Group).

  8. ALICE - ARC integration

    DEFF Research Database (Denmark)

    Anderlik, Csaba; Gregersen, Anders Rhod; Kleist, Josva;

    AliEn or Alice Environment is the Gridware developed and used within the ALICE collaboration for storing and processing data in a distributed manner. ARC (Advanced Resource Connector) is the Grid middleware deployed across the Nordic countries and gluing together the resources within the Nordic...... Data Grid Facility (NDGF). In this paper we will present our approach to integrate AliEn and ARC, in the sense that ALICE data management and job processing can be carried out on the NDGF infrastructure, using the client tools available in AliEn. The interoperation has two aspects, one is the data...... management part and the second the job management aspect. The first aspect was solved by using dCache across NDGF to handle data. dCache provides support for several data management tools (among them for xrootd the tools used by AliEn) using the so called "doors". Therefore, we will concentrate on the second...

  9. Modeling rf breakdown arcs

    CERN Document Server

    Insepov, Zeke; Huang, Dazhang; Mahalingam, Sudhakar; Veitzer, Seth

    2010-01-01

    We describe breakdown in 805 MHz rf accelerator cavities in terms of a number of mechanisms. We devide the breakdown process into three stages: (1) we model surface failure using molecular dynamics of fracture caused by electrostatic tensile stress, (2) we model the ionization of neutrals responsible for plasma initiation and plasma growth using a particle in cell code, and (3) we model surface damage by assuming a process similar to unipolar arcing. Although unipolar arcs are strictly defined with equipotential boundaries, we find that the cold, dense plasma in contact with the surface produces very small Debye lengths and very high electric fields over a large area. These high fields produce strong erosion mechanisms, primarily self sputtering, compatible with the crater formation that we see. Results from the plasma simulation are included as a guide to experimental verification of this model.

  10. The ARCS radial collimator

    OpenAIRE

    Stone M.B.; Niedziela J.L.; Overbay M.A.; Abernathy D.L.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. W...

  11. Circular arc structures

    KAUST Repository

    Bo, Pengbo

    2011-07-01

    The most important guiding principle in computational methods for freeform architecture is the balance between cost efficiency on the one hand, and adherence to the design intent on the other. Key issues are the simplicity of supporting and connecting elements as well as repetition of costly parts. This paper proposes so-called circular arc structures as a means to faithfully realize freeform designs without giving up smooth appearance. In contrast to non-smooth meshes with straight edges where geometric complexity is concentrated in the nodes, we stay with smooth surfaces and rather distribute complexity in a uniform way by allowing edges in the shape of circular arcs. We are able to achieve the simplest possible shape of nodes without interfering with known panel optimization algorithms. We study remarkable special cases of circular arc structures which possess simple supporting elements or repetitive edges, we present the first global approximation method for principal patches, and we show an extension to volumetric structures for truly threedimensional designs. © 2011 ACM.

  12. TECHNOLOGY EVALUATION REPORT: RETECH'S PLASMA CENTRIFUGAL FURNACE - VOLUME I

    Science.gov (United States)

    A demonstration of the Retech, Inc. Plasma Centrifugal Furnace (PCF) was conducted under the Superfund Innovative Technology Evaluation (SITE) Program at the Department of Energy's (DOE's) Component Development and Integration Facility in Butte, Montana. The furnace uses heat gen...

  13. Cast functional accessories for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    A. Drotlew

    2010-10-01

    Full Text Available The study gives examples of the cast functional accessories operating in furnaces for the heat treatment of metals and alloys. The describeddesign solutions of castings and their respective assemblies are used for charge preparation and handling. They were put in systematicorder depending on furnace design and the technological purpose of heat treatment. Basic grades of austenitic cast steel, used for castings of this type, were enumerated, and examples of general guidelines formulated for their use were stated. The functional accessories described in this study were designed and made by the Foundry Research Laboratory of West Pomeranian University of Technology.

  14. Measure Guideline: High Efficiency Natural Gas Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L.; Rose, W.

    2012-10-01

    This Measure Guideline covers installation of high-efficiency gas furnaces. Topics covered include when to install a high-efficiency gas furnace as a retrofit measure, how to identify and address risks, and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  15. Measure Guideline. High Efficiency Natural Gas Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States); Rose, W. [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

    2012-10-01

    This measure guideline covers installation of high-efficiency gas furnaces, including: when to install a high-efficiency gas furnace as a retrofit measure; how to identify and address risks; and the steps to be used in the selection and installation process. The guideline is written for Building America practitioners and HVAC contractors and installers. It includes a compilation of information provided by manufacturers, researchers, and the Department of Energy as well as recent research results from the Partnership for Advanced Residential Retrofit (PARR) Building America team.

  16. Optimization of Temperature Controller for Electric Furnace

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Genetic algorithms are based on the principle of natural selection and the optimization of natural generation. We can select the number of the bit strings and mutation rate reasonably, the global optimal solution can be obtained. GAs adopt the binary code as optimizing parameter and this binary code can be used in computer controller easily. This paper studies the application of the GAs to the electric furnace temperature control. When the electric furnace mathematics model varies with the working condition, the parameter of controller can be optimized on line. So the system performance can be improved effectively.

  17. Waste and dust utilisation in shaft furnaces

    Directory of Open Access Journals (Sweden)

    Senk, D.

    2005-12-01

    Full Text Available Wastes and dusts from steel industry, non-ferrous metallurgy and other branches can be utilized e.g. in agglomeration processes (sintering, pelletizing or briquetting and by injection into shaft furnaces. This paper deals with the second way. Combustion and reduction behaviour of iron- and carbon-rich metallurgical dusts and sludges containing lead, zinc and alkali as well as other wastes with and without pulverized coal (PC has been studied when injecting into shaft furnaces. Following shaft furnaces have been examined: blast furnace, cupola furnace, OxiCup furnace and imperial-smelting furnace. Investigations have been done at laboratory and industrial scale. Some dusts and wastes under certain conditions can be not only reused but can also improve combustion efficiency at the tuyeres as well as furnace performance and productivity.

    Los residuos y polvos de filtro provenientes de la industria siderúrgica, de la obtención de metales no ferrosos y de otras industrias, pueden ser utilizados, por ejemplo, en procesos de aglomeración como sintetizado, peletizado o briqueteado. En su caso, estos pueden ser inyectados en los hornos de cuba. Este artículo se enfoca a la inyección de estos materiales en los hornos de cuba. El comportamiento de la combustión y reducción de los polvos ricos en hierro y carbono y también lodos que contienen plomo, zinc y compuestos alcalinos y otros residuos con o sin carbón pulverizado (CP fue examinado, cuando se inyectaron en hornos de cuba. Los siguientes hornos de cuba fueron examinados: Horno alto, cubilote, OxiCup y horno de cuba Imperial Smelting. Las investigaciones se llevaron a cabo a escala de laboratorio e industrial. Algunos residuos y polvos bajo ciertas condiciones, no sólo pueden ser reciclados, sino también mejoran la eficiencia de combustión en las toberas, la operación y productividad del horno.

  18. Arc-preserving subsequences of arc-annotated sequences

    CERN Document Server

    Popov, Vladimir Yu

    2011-01-01

    Arc-annotated sequences are useful in representing the structural information of RNA and protein sequences. The longest arc-preserving common subsequence problem has been introduced as a framework for studying the similarity of arc-annotated sequences. In this paper, we consider arc-annotated sequences with various arc structures. We consider the longest arc preserving common subsequence problem. In particular, we show that the decision version of the 1-{\\sc fragment LAPCS(crossing,chain)} and the decision version of the 0-{\\sc diagonal LAPCS(crossing,chain)} are {\\bf NP}-complete for some fixed alphabet $\\Sigma$ such that $|\\Sigma| = 2$. Also we show that if $|\\Sigma| = 1$, then the decision version of the 1-{\\sc fragment LAPCS(unlimited, plain)} and the decision version of the 0-{\\sc diagonal LAPCS(unlimited, plain)} are {\\bf NP}-complete.

  19. A Solar Furnace for Your School

    Science.gov (United States)

    Meyer, Edwin C.

    1978-01-01

    Industrial arts students at Litchfield (Minnesota) High School designed and built a solar furnace for research and experimentation and to help heat the industrial arts department. A teacher describes the construction process and materials and the temperature record keeping by the physics classes. Student and community interest has been high. (MF)

  20. Titanat aluminium synthesized in a solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Suleimanov, S.; Gulamova, D. [Uzbek Academy of Sciences, Tashkent (Uzbekistan). Materials Science Inst.; Boehmer, M.; Fend, T.; Rietbrock, P. [DLR, Koeln (Germany). MD-ET

    1997-12-31

    Solar furnace technology is an ecologically clean and economically attractive way, most suitable for research and development of new advanced materials. Such features of the solar furnace as sterile conditions of heating, high speed temperature delivering, materials processing in the whole range of the solar spectrum, quenching of the melt with rates of {proportional_to}10{sup 6} K/s, possibility of melting in the cold crucible etc. allow to synthesize complex oxide compositions, such as Al{sub 2}TiO{sub 5}. The study of Al{sub 2}TiO{sub 5} synthesized in the solar furnace has shown that the material is pure {beta}-Al{sub 2}TiO{sub 5} and possesses orthorhombic crystal structure. Microstructure of the material obtained from the melt has a prolonged prismatic shape. When the material is obtained by quenching the microstructure displays fine-grain structure with crystallites of 3-5 micron in size. Raman spectroscopy investigations have been performed on {beta}-Al{sub 2}TiO{sub 5} synthesized on the solar furnace. It has been observed a distinct band at 900 1/cm which is not presented in other six coordinated titanates. Most probably this band is connected with valent vibrations of the Al-O coupling in distorted octahedrons [AlO{sub 6}]. (orig.)

  1. APPLICATION ANALYSIS REPORT: RETECH PLASMA CENTRIFUGAL FURNACE

    Science.gov (United States)

    This document is an evaluation of the performance of the Retech, Inc. Plasma Centrifugal Furnace (PCF) and its applicability as a treatment for soils contaminated with organic and/or inorganic compounds. Both the technical and economic aspectsof the technology were examined. A...

  2. INVESTIGATIONS ON OPERATION OF ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available Rotary tilting furnace (RTF is a new type of fuel furnaces, that provide the most efficient heating and recycling of polydisperse materials. The paper describes results of the investigations on thermal processes in the RTF, movement of materials and non-isothermal gas flow during kiln rotary process. The investigations have been carried out while using physical and computer simulations and under actual operating conditions applying the pilot plant. Results of the research have served as a basis for development of recommendations on the RTF calculations and designing and they have been also used for constructional design of a rotary tilting furnace for heating and melting of cast iron chips, reduction smelting of steel mill scale, melting of aluminum scrap, melting of lead from battery scrap. These furnaces have a high thermal efficiency (~50 %, technological flexibility, high productivity and profitability. Proven technical solutions for recycling of ferrous and non-ferrous metals develop the use of RTF in the foundry and metallurgical industry as the main technological unit for creation of cost-effective small-tonnage recycling of metal waste generated at the plants. The research results open prospects for organization of its own production for high-quality charging material in Belarus in lieu of imported primary metal. The proposed technology makes it possible to solve environmental challenge pertaining to liquidation of multi-tonnage heaps of metal-containing wastes.

  3. High Vacuum Furnace for HIRFL-CSR

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to satisfy the requirement of ultra-high vacuum and low out-gassing rate of materials which are used to make HIIRFL-CSR vacuum chambers, a high vacuum furnace for degassing the beam chambers, flanges, and the other vacuum components has been designed and manufactured by IMP and Vacuum Equipment Factory in Lanzhou.

  4. Energy conservation in cupolas and annealing furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Takeno, S.; Kumagaya, M.; Azuma, T.

    1984-01-01

    Successive reductions in the amount of coke and fuel oil used in cupolas and annealing furnaces are reported. In the cupolas, 2% oxygen enrichment resulted in a 0.9% drop in coke ratio and a 13.3% increase in output of pig iron. Coke ratios of 9.3-9.5% were obtained by tuyere blow-in of inexpensive carbon materials instead of expensive coke, by the use of formed coke, and by employing a dehumidified blast. In the case of the fuel oil-fired annealing furnaces, fuel oil consumption rates were reduced by treating two charges per heat instead of one. Energy consumption was successively reduced by 25-71% by 1) adopting a ceramic fibre heat-insulating material, 2) changing to low-oxygen combustion by increasing the number of burners, 3) lengthening the time during which the furnace high-temperature zone is maintained, 4) raising the combustion chamber load by using ceramic fibres in the furnace casing. 3 references.

  5. Calibration procedure for fire resistance furnaces

    NARCIS (Netherlands)

    Twilt, L.; Leur, P.H.E. van de; Wickström, U.

    1996-01-01

    On behalf of CEN/TC 127 "Fire Safety in Buildings", a series of tests has been carried out to evaluate and complete the draft calibration procedure for fire resistance furnaces [4]. Fourteen laboratories in nine European countries participated in the test series, each carrying out one calibration te

  6. Effect of electropolishing on vacuum furnace design

    Directory of Open Access Journals (Sweden)

    Sutanwi Lahiri

    2015-03-01

    Full Text Available The use of thermal shields of materials having low emissivity in vacuum furnaces is well-known. However, the surface condition of the heat shields is one of the most important factors governing their efficiency as radiation resistances. The emissivity of the thermal shields dictates the power rating of the heaters in furnace design. The unpolished materials used in the heater tests showed poor performance leading to loss of a signi­ficant percentage of the input power. The present work deals with the refur­bishment of the radiation heat shields used in a furnace for heating graphite structure. The effect of refurbishment of the heat shields by the buffing and subsequently electro­polishing was found to improve the performance of the shields as heat reflectors. The com­position of the electrolyte was chosen in such a way that the large shields of Mo, Inconel and SS can be polished using the same reagents in different ratios. The present work deals with the development of a standard electropolishing procedure for large metallic sheets and subsequently qualifying them by roughness and emissivity measure­ments. The improvement noted in the shielding efficiency of the furnace in the subsequent runs is also discussed here.

  7. Thermal exposure in fire resistance furnaces

    NARCIS (Netherlands)

    Leur, P.H.E. van de; Twilt, L.

    1999-01-01

    Over the last six years, CEN TC 127 and more in particular its working groups ad hoc 14 and ad hoc 7 have been active in evaluating and improving the reproducibility of fire resistance testing. Ad hoc 14 developed a draft procedure for the evaluation of the performance of fire resistance furnaces in

  8. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  9. Thermal Analysis of an Industrial Furnace

    Directory of Open Access Journals (Sweden)

    Mirko Filipponi

    2016-10-01

    Full Text Available Industries, which are mainly responsible for high energy consumption, need to invest in research projects in order to develop new managing systems for rational energy use, and to tackle the devastating effects of climate change caused by human behavior. The study described in this paper concerns the forging industry, where the production processes generally start with the heating of steel in furnaces, and continue with other processes, such as heat treatments and different forms of machining. One of the most critical operations, in terms of energy loss, is the opening of the furnace doors for insertion and extraction operations. During this time, the temperature of the furnaces decreases by hundreds of degrees in a few minutes. Because the dispersed heat needs to be supplied again through the combustion of fuel, increasing the consumption of energy and the pollutant emissions, the evaluation of the amount of lost energy is crucial for the development of systems which can contain this loss. To perform this study, CFD simulation software was used. Results show that when the door opens, because of temperature and pressure differences between the furnace and the ambient air, turbulence is created. Results also show that the amount of energy lost for an opening of 10 min for radiation, convection and conduction is equal to 5606 MJ where convection is the main contributor, with 5020 MJ. The model created, after being validated, has been applied to perform other simulations, in order to improve the energy performance of the furnace. Results show that reducing the opening time of the door saves energy and limits pollutant emissions.

  10. The ARCS radial collimator

    Directory of Open Access Journals (Sweden)

    Stone M.B.

    2015-01-01

    Full Text Available We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. We present here characterization of the collimator's performance and methodologies for its effective use.

  11. The ARCS radial collimator

    Science.gov (United States)

    Stone, M. B.; Niedziela, J. L.; Overbay, M. A.; Abernathy, D. L.

    2015-01-01

    We have designed, installed, and commissioned a scattered beam radial collimator for use at the ARCS Wide Angular Range Chopper Spectrometer at the Spallation Neutron Source. The collimator has been designed to work effectively for thermal and epithermal neutrons and with a range of sample environments. Other design considerations include the accommodation of working within a high vacuum environment and having the ability to quickly install and remove the collimator from the scattered beam. We present here characterization of the collimator's performance and methodologies for its effective use.

  12. Correlation methods in cutting arcs

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L; Kelly, H, E-mail: prevosto@waycom.com.ar [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Universidad Tecnologica Nacional, Regional Venado Tuerto, Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina)

    2011-05-01

    The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.

  13. AUTOMATION OF GLASS TEMPERING FURNACE BY USING PLC

    Directory of Open Access Journals (Sweden)

    Abdullah BÜYÜKYILDIZ

    2007-02-01

    Full Text Available In this study, a furnace which is used for observation of environments under high temperature, and also used for manufacturing of glasses which are resisted to high temperature has been designed and implemented. Automation of this system has been done by using PLC. Operating parameters of furnace such as materials entering, the furnace, the local temperature control of furnace, cooling control and materials outing have been sensed with Hall Effect Sensor. Furthermore, the observation of parameters of furnace on screen has been provided with SCADA software. Obtained products have been shown the system works successfully.

  14. Characterization of the behaviour of the electric arc during VAR of a Ti alloy

    Science.gov (United States)

    Chapelle, P.; Noël, C.; Risacher, A.; Jourdan, J.; Jourdan, J.; Jardy, A.

    2016-07-01

    In this paper, we report experimental results based on the direct observation of the electric arc behaviour during vacuum arc remelting of a Ti alloy. These results were obtained in a specifically instrumented industrial furnace using high speed framing camera and optical emission spectroscopy, for a current density level of the order of 10 A/cm2 and a gap length of a few centimetres. It was observed that the arc exhibits a similar operating regime to that described in the literature for the case of Inconel 718 and Zr alloy electrodes. The arc structure corresponds essentially to that of a diffuse metal vapor arc with separate and rapidly moving cathode spots. Several critical parameters of the cathode spots, including their current, size and velocity, and of the interelectrode plasma were evaluated. Also, the interactions between the arc operation and the transfer of metal drops in the interelectrode gap were investigated. Three modes of transfer of the liquid metal drops in the interelectrode gap have been identified depending on the gap length: drop falling, drip short and drop erosion induced by the cathode spots.

  15. Efficient 'Optical Furnace': A Cheaper Way to Make Solar Cells is Reaching the Marketplace

    Energy Technology Data Exchange (ETDEWEB)

    von Kuegelgen, T.

    2008-10-01

    In Bhushan Sopori's laboratory, you'll find a series of optical furnaces he has developed for fabricating solar cells. When not in use, they sit there discreetly among the lab equipment. But when a solar silicon wafer is placed inside one for processing, Sopori walks over to a computer and types in a temperature profile. Almost immediately this fires up the furnace, which glows inside and selectively heats up the silicon wafer to 800 degrees centigrade by the intense light it produces. Sopori, a principal engineer at the National Renewable Energy Laboratory, has been researching and developing optical furnace technology for around 20 years. He says it's a challenging technology to develop because there are many issues to consider when you process a solar cell, especially in optics. Despite the challenges, Sopori and his research team have advanced the technology to the point where it will benefit all solar cell manufacturers. They are now developing a commercial version of the furnace in partnership with a manufacturer. 'This advanced optical furnace is highly energy efficient, and it can be used to manufacture any type of solar cell,' he says. Each type of solar cell or manufacturing process typically requires a different furnace configuration and temperature profile. With NREL's new optical furnace system, a solar cell manufacturer can ask the computer for any temperature profile needed for processing a solar cell, and the same type of furnace is suitable for several solar cell fabrication process steps. 'In the future, solar cell manufacturers will only need this one optical furnace because it can be used for any process, including diffusion, metallization and oxidation,' Sopori says. 'This helps reduce manufacturing costs.' One startup company, Applied Optical Systems, has recognized the furnace's potential for manufacturing thin-film silicon cells. 'We'd like to develop thin-film silicon cells

  16. Second generation rotary furnaces, an even more viable alternative to cupola and electric induction furnaces; La seconde generation de fours rotatifs, un appareil qui peut se substituer avantageusement au cubilot et au four electrique a induction

    Energy Technology Data Exchange (ETDEWEB)

    Lever, D. [Air Liquide 38 - Sassenage (France)

    2001-10-01

    Rotary furnaces are a well established alternative to cupola furnaces. Recent innovations in oxygas furnaces have made them the preferred choice even over medium-frequency electric furnaces in many European foundries. The article explains in what respects the rotary furnace is a new iron smelting concept, as different from the cupola furnace as the medium-frequency electric furnace. (author)

  17. Alternating-Polarity Arc Welding

    Science.gov (United States)

    Schwinghamer, R. J.

    1987-01-01

    Brief reversing polarity of welding current greatly improves quality of welds. NASA technical memorandum recounts progress in art of variable-polarity plasma-arc (VPPA) welding, with emphasis on welding of aluminum-alloy tanks. VPPA welders offer important advantages over conventional single-polarity gas/tungsten arc welders.

  18. Compensation for Power Quality Improvement in Electric Arc Furnace with Considering Economic Index

    OpenAIRE

    2012-01-01

    In recent years, on the one hand with increasing application of nonlinear loads in power systems and no sinusoidal currents that extracted from system, and on the other hand increasing loads sensitive to power quality and destructive effects of nonlinear loads on power quality of power systems, compensation these loads has been converted to one of the main issues in power systems. The use of flexible AC transmission system (FACTS) devices is one of the most progressive methods which are used ...

  19. Recycling of electric arc furnace (EAF dust for use in steel making process

    Directory of Open Access Journals (Sweden)

    José Alencastro de Araújo

    2014-07-01

    Full Text Available The EAF dust is listed as hazardous waste from specific source, K061, according to ABNT 10004:2004 and constitutes one of the major problems of electrical steel plant. This work suggests recycling of the EAF dust by sintering of a composite, pre-cast agglomerate (PCA consisting of EAF dust agglomerate to coke particles, mill scale and ceramic fluorite into pellets. The work was divided into three stages, in the first stage the technical viability of using only solid waste industrial to produce a PCA was observed, in the second phase, the main effects between the components of the PCA to obtain the optimal formulation was tested. In the third phase the intensity of the variables, coke and fluorite ceramics, for removing zinc of PCA was checked. Every stage was chemically analyzed by X-ray fluorescence spectrometer and X-ray diffraction. The first two stages of the production PCA were carried out in a pilot plant sintering downstream and the third phase in a pilot plant upstream. As a result of the process two by-products were obtained, the pre-cast agglomerated, PCA, with total iron content exceeding 70%, object of the process of sintering and zinc dust, containing more than 50% zinc resulting from volatilization of this metal during the sintering process and collected by bag filter. In addition, approximately 90% of lead and cadmium contained in the initial EAF dust was extracted.

  20. [Health surveillance in a steel making industry with electric arc furnace: 15 years of experience].

    Science.gov (United States)

    Corti, P

    2012-01-01

    This paper analyzes the results of health surveillance carried out in an electric steel mill for 15 years. We have analyzed the trend of audiometry, spirometry and main indicators of exposure to chemical risk: serum lead, urinary OH-pyrene, erythrocyte ZPP, and the results of risk assessment of stress work related. The analyses of the trend of audiometry, spirometry and biological monitoring shows an important improving in the working environment due to the progressive automation of production steps in the course of several years, consistent and correct use of DPI, information and training.

  1. A Study on Properties of Electrical Conductive Bricks for Direct Current Electrical Arc Furnace

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    In this expeiment,the effects of temperature and graphite content on the electricl conductivity of MgO-C materials are studied,Experimental results indicated:the proper ontent of graphite is 10%-12%,The specific electrical resistance of MgO-C materials tends to decrease as the preheat treatment temerature rises.After heat treatment,the specific electrical resistance of MgO-C materials is nearly independent of temperature.

  2. A Kinetic Ladle Furnace Process Simulation Model: Effective Equilibrium Reaction Zone Model Using FactSage Macro Processing

    Science.gov (United States)

    Van Ende, Marie-Aline; Jung, In-Ho

    2017-02-01

    The ladle furnace (LF) is widely used in the secondary steelmaking process in particular for the de-sulfurization, alloying, and reheating of liquid steel prior to the casting process. The Effective Equilibrium Reaction Zone model using the FactSage macro processing code was applied to develop a kinetic LF process model. The slag/metal interactions, flux additions to slag, various metallic additions to steel, and arcing in the LF process were taken into account to describe the variations of chemistry and temperature of steel and slag. The LF operation data for several steel grades from different plants were accurately described using the present kinetic model.

  3. Characteristics of Arcs Between Porous Carbon Electrodes

    OpenAIRE

    Carvou, Erwann; Le Garrec, Jean-Luc; Mitchell, Brian

    2013-01-01

    International audience; Arcs between carbon electrodes present some specific differences compared with metallic arcs. The arc voltage is higher, but does not attain a stable value displaying large fluctuations. Indeed, the arcs are produced by the direct sublimation of the electrodes, without passing through a molten phase. The arc production is also facilitated by both circuit breaking and electric field breakdown. In this paper, arcing has been examined under various conditions (voltage, cu...

  4. Solar furnace sintering of ceramic materials

    Energy Technology Data Exchange (ETDEWEB)

    Zhilinska, N.; Zalite, I.; Korb, G.; Angerer, P.; Rodriguez, J.; Martinez, D.

    2004-07-01

    This paper reports on the current status of application of solar furnace for sintering of TiCN, TiO2 and Al2O3 nano powders with the specific surface area of 30-50 m''2/g and average particle size of 30-50 nm. The powders have been prepared by the plasma chemical synthesis and other methods. This work relates to innovative methods of sintering in the solar furnace at Plataforma Solar de Almeria and the Spark Plasma Sintering (SPS). The influence of sintering temperature, sintering time and heating rate on the densification behaviour of the nanopowders was investigated. The results were compared with the data obtained using commercial powders. (Author) 4 refs.

  5. FEM Optimisation of Spark Plasma Sintering Furnace

    CERN Document Server

    Kellari, Demetrios Vasili

    2013-01-01

    Coupled electro-thermal FEM analysis has been carried out on a sintering furnace used to produce new materials for LHC collimators. The analysis showed there exist margins for improvement of the current process and equipment through minor changes. To optimise the design of the furnace several design changes have been proposed including: optimization of material selection using copper cooling plates, control of convection in cooling plates by lowering the water flow rate, modifying the electrode shape using unsymmetrical electrodes and upgrading the thermal shielding to make use of multilayer graphite shields. The results show that we have a significant improvement in temperature gradient on the plate, from 453 to 258 °C and a reduction in power requirement from 62 to 44 kW.

  6. Fabrication of the solar furnace`s segmental main parabolic mirror

    Energy Technology Data Exchange (ETDEWEB)

    Shishido, K. [Tohoku Gakuin Univ., Tagajo, Miyagi (Japan); Kitahara, H. [Tohoku Electric Power Co. Ltd., Sendai (Japan); Fujisaki, H.; Shoji, T. [Tohoku Gakuin Univ., Tagajo, Miyagi (Japan); Shibata, Y. [Tohoku Univ., Sendai (Japan); Sugiura, M. [Koyodai High School, Miyagi, Sendai (Japan); Nagai, Y. [Press Kogyo Company Ltd., Fujisawa (Japan); Kobayashi, H. [Tokyo Special Glass Company Ltd., Fujioka (Japan)

    1994-12-31

    The development of a new energy system based on the concentration of the rays of the sun was trialed and four solar furnaces produced. However, the fabrication of the segmented main parabolic mirror required high precision and was found to be very difficult. The main parabolic mirror of the furnaces were of the segmental type. The mirrors in the large furnace of the first trial in 1962 were made by a cutting machine with a cam mechanism and then finished by grinding and polishing. The segmental main parabolic mirrors of the small and medium-size furnaces (2nd and 3rd trials) were made using master molds (for softening the glass segments) that were fabricated using a cutting machine having a link mechanism. The fourth furnace used mirrors composed of super reflecting A1 plate cemented on a stamped plastic base. The cutting techniques and the grinding and polishing of the glass to fabricate the fan-shaped segmental parabolic mirrors were successful, but the softening results were not ideal. Better results were obtained on softening narrow fan-shaped glass plates and the ideal tools for cutting the master molds of soft brick are considered to be the glass gauge or cylinder tube. 10 figs., 4 refs.

  7. Concentration of a Cassegrain solar furnace

    Science.gov (United States)

    Cobble, M. H.

    1981-01-01

    A solar furnace comprising a paraboloidal mirror for tracking the sun and a hyperboloidal reflector having one focus in common with the paraboloid is analyzed to determine the geometric concentration of the system. A numerical ray-trace analysis was carried out to study various geometrical configurations of the two reflectors. In particular, the geometric concentration is calculated for the case when the line joining the foci of the hyperboloid and the axis of revolution of the paraboloid are not coincident.

  8. Temperature Controller for a Solar Furnace

    Science.gov (United States)

    Hale, R. R.; Mcdougal, A. R.

    1982-01-01

    Relatively-simple movable sheild has been suggested for controlling temperature of solar furnace. Temperature modulator can be set to have collected solar energy fully "on", fully "off" or any intermediate level. Parabolic mirror concentrates Sunlight into receiver. Shade plate that blocks insolation at back of receiver produces shade zone in center of collector. No radiation is returned to receiver from shade zone; only rays falling on other areas of reflecting surface are directed back toward receiver.

  9. Carbon sublimation using a solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Laplaze, D. [Montpellier-2 Univ. (France). Groupe de Dynamique des Phases Condensees; Bernier, P. [Montpellier-2 Univ. (France). Groupe de Dynamique des Phases Condensees; Journet, C. [Montpellier-2 Univ. (France). Groupe de Dynamique des Phases Condensees; Vie, V. [Montpellier-2 Univ. (France). Groupe de Dynamique des Phases Condensees; Flamant, G. [Montpellier-2 Univ. (France). Groupe de Dynamique des Phases Condensees]|[Inst. de Science et de Genie des Materiaux et Procedes, Centre du Four Solaire Felix Trombe, Font-Romeu (France); Lebrun, M. [Montpellier-2 Univ. (France). Groupe de Dynamique des Phases Condensees]|[Inst. de Science et de Genie des Materiaux et Procedes, Centre du Four Solaire Felix Trombe, Font-Romeu (France)

    1997-02-28

    We have previously shown that the high intensity of solar radiation, obtained with the Odeillo (France) solar furnace facilities, can be used to vaporize graphite in inert gas atmosphere to produce fullerenes. After a short survey of the possible mechanisms of formation of these molecules, we report some results in agreement with the proposed model and discuss the possibilities of increasing the fullerene yield which currently reaches 20% (orig.)

  10. A virtual crystallization furnace for solar silicon

    Energy Technology Data Exchange (ETDEWEB)

    Steinbach, I.; Franke, D. [ACCESS e.V., Aachen (Germany); Krumbe, W.; Liebermann, J. [Bayer AG, Krefeld-Uerdingen (Germany)

    1994-12-31

    Blocks of silicon for photovoltaic applications are economically crystallized in large casting furnaces. The quality of the material is determined by the velocity of the crystallization front, the flatness of the liquid-solid interface and the thermal gradients in the solid during cooling. The process cycle time, which is determined by the rate of crystallization and cooling, has a large effect on the process economic viability. Traditionally trial and error was used to determine the process control parameters, the success of which depended on the operator`s experience and intuition. This paper presents a numerical model, which when completed by a fitted data set, constitutes a virtual model of a real crystallization furnace, the Virtual Crystallization Furnace (VCF). The time-temperature distribution during the process cycle is the main output, which includes a display of actual liquid-solid front position. Moreover, solidification velocity, temperature gradients and thermal stresses can be deduced from this output. The time needed to run a simulation on a modern work-station is approximately 1/6 of real process time, thereby allowing the user to make many process variations at very reasonable costs. Therefore the VCF is a powerful tool for optimizing the process in order to reduce cycle time and to increase product quality.

  11. Arc Interference Behavior during Twin Wire Gas Metal Arc Welding Process

    Directory of Open Access Journals (Sweden)

    Dingjian Ye

    2013-01-01

    Full Text Available In order to study arc interference behavior during twin wire gas metal arc welding process, the synchronous acquisition system has been established to acquire instantaneous information of arc profile including dynamic arc length variation as well as relative voltage and current signals. The results show that after trailing arc (T-arc is added to the middle arc (M-arc in a stable welding process, the current of M arc remains unchanged while the agitation increases; the voltage of M arc has an obvious increase; the shape of M arc changes, with increasing width, length, and area; the transfer frequency of M arc droplet increases and the droplet itself becomes smaller. The wire extension length of twin arc turns out to be shorter than that of single arc welding.

  12. Controllability of arc jet from arc horns with slits. Slit tsuki arc horn no arc jet seigyo tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Sunabe, K.; Inaba, T.; Fukagawa, H. (Central Research Institute of Electric Power Industry, Tokyo (Japan)); Kito, Y. (Nagoya University, Nagoya (Japan))

    1993-09-20

    To improve the corona discharge characteristics, test preparation was made of hollow rod form horns with slits for the overhead power transmission line use. Two types of horn electrode were prepared. The first horn electrode is of a hollow hemisphere fitted with and divided by slits on its tip. The second horn electrode is the first one which is further fitted with rod form electrode at the center of its tip. In experiment, relation was obtained between the deflection angle of arc jet and arc current, electrode diameter, etc., through an observation of arc jet by high speed camera. Melting loss of electrode was also made clear. The following knowledge was obtained: For the first horn electrode, the deflection angle can be limited to a narrow range by a division with slits, e.g., within 30 degrees under the condition of 5kA in arc current, 4 in number of sectors and 200mm in diameter. For the second horn electrode, the deflection angle can be limited to within 20 degrees under the condition of 5kA in arc current and 4 in number of sectors. The arc current is also limited to below 5kA by an addition of 50mm diameter central electrode. As a conclusion for the first electrode, the arc jet control characteristics excels in the stronger arc current range than 5kA, while for the second electrode, they are effective in the weaker arc current range than 5kA. 6 refs., 19 figs., 1 tab.

  13. 77 FR 76831 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Furnaces and...

    Science.gov (United States)

    2012-12-31

    ... Furnaces and Boilers (June 7, 2010),\\5\\ the ENERGY STAR Product Databases for Gas and Oil Furnaces (Jan. 4, 2010),\\6\\ the California Energy Commission's Appliance Database for Residential Furnaces and Boilers,\\7.... Department of Commerce, ENERGY STAR Furnaces--Product Databases for Gas and Oil Furnaces (Jan. 4,...

  14. Sealed rotary hearth furnace with central bearing support

    Science.gov (United States)

    Docherty, James P.; Johnson, Beverly E.; Beri, Joseph

    1989-01-01

    The furnace has a hearth which rotates inside a stationary closed chamber and is supported therein on vertical cylindrical conduit which extends through the furnace floor and is supported by a single center bearing. The charge is deposited through the furnace roof on the rim of the hearth as it rotates and is moved toward the center of the hearth by rabbles. Externally generated hot gases are introduced into the furnace chamber below the hearth and rise through perforations in the hearth and up through the charge. Exhaust gases are withdrawn through the furnace roof. Treated charge drops from a center outlet on the hearth into the vertical cylindrical conduit which extends downwardly through the furnace floor to which it is also sealed.

  15. Arc spot grouping: An entanglement of arc spot cells

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Shin, E-mail: kajita.shin@nagoya-u.jp [EcoTopia Science Institute, Nagoya University, Nagoya 464-8603 (Japan); Hwangbo, Dogyun; Ohno, Noriyasu [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Tsventoukh, Mikhail M. [Lebedev Physical Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation); Barengolts, Sergey A. [Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow 119991 (Russian Federation)

    2014-12-21

    In recent experiments, clear transitions in velocity and trail width of an arc spot initiated on nanostructured tungsten were observed on the boundary of the thick and thin nanostructured layer regions. The velocity of arc spot was significantly decreased on the thick nanostructured region. It was suggested that the grouping decreased the velocity of arc spot. In this study, we try to explain the phenomena using a simple random walk model that has properties of directionality and self-avoidance. And grouping feature was added by installing an attractive force between spot cells with dealing with multi-spots. It was revealed that an entanglement of arc spot cells decreased the spot velocity, and spot cells tend to stamp at the same location many times.

  16. Convergent evolution of the arginine deiminase pathway: the ArcD and ArcE arginine/ornithine exchangers.

    Science.gov (United States)

    Noens, Elke E E; Lolkema, Juke S

    2017-02-01

    The arginine deiminase (ADI) pathway converts L-arginine into L-ornithine and yields 1 mol of ATP per mol of L-arginine consumed. The L-arginine/L-ornithine exchanger in the pathway takes up L-arginine and excretes L-ornithine from the cytoplasm. Analysis of the genomes of 1281 bacterial species revealed the presence of 124 arc gene clusters encoding the pathway. About half of the clusters contained the gene encoding the well-studied L-arginine/L-ornithine exchanger ArcD, while the other half contained a gene, termed here arcE, encoding a membrane protein that is not a homolog of ArcD. The arcE gene product of Streptococcus pneumoniae was shown to take up L-arginine and L-ornithine with affinities of 0.6 and 1 μmol/L, respectively, and to catalyze metabolic energy-independent, electroneutral exchange. ArcE of S. pneumoniae could replace ArcD in the ADI pathway of Lactococcus lactis and provided the cells with a growth advantage. In contrast to ArcD, ArcE catalyzed translocation of the pathway intermediate L-citrulline with high efficiency. A short version of the ADI pathway is proposed for L-citrulline catabolism and the presence of the evolutionary unrelated arcD and arcE genes in different organisms is discussed in the context of the evolution of the ADI pathway.

  17. Anomaly detection of blast furnace condition using tuyere cameras

    Science.gov (United States)

    Yamahira, Naoshi; Hirata, Takehide; Tsuda, Kazuro; Morikawa, Yasuyuki; Takata, Yousuke

    2016-09-01

    We present a method of anomaly detection using multivariate statistical process control(MSPC) to detect the abnormal behaviors of a blast furnace. Tuyere cameras attached circumferentially at the lower side of a blast furnace are used to monitor the inside of the furnace and this method extracts abnormal behaviors of intensities. It is confirmed that with our method, detecting timing is earlier than operators' notice. Besides, misalignment of cameras doesn't affect detecting performance, which is important property in actual use.

  18. On arc efficiency in gas tungsten arc welding

    Directory of Open Access Journals (Sweden)

    Nils Stenbacka

    2013-12-01

    Full Text Available The aim of this study was to review the literature on published arc efficiency values for GTAW and, if possible, propose a narrower band. Articles between the years 1955 - 2011 have been found. Published arc efficiency values for GTAW DCEN show to lie on a wide range, between 0.36 to 0.90. Only a few studies covered DCEP - direct current electrode positive and AC current. Specific information about the reproducibility in calorimetric studies as well as in modeling and simulation studies (considering that both random and systematic errors are small was scarce. An estimate of the average arc efficiency value for GTAW DCEN indicates that it should be about 0.77. It indicates anyway that the GTAW process with DCEN is an efficient welding method. The arc efficiency is reduced when the arc length is increased. On the other hand, there are conflicting results in the literature as to the influence of arc current and travel speed.

  19. Biological Kraft Chemical Recycle for Augmentation of Recovery Furnace Capacity

    Energy Technology Data Exchange (ETDEWEB)

    Stuart E. Strand

    2001-12-06

    The chemicals used in pulping of wood by the kraft process are recycled in the mill in the recovery furnace, which oxidizes organics while simultaneously reducing sulfate to sulfide. The recovery furnace is central to the economical operation of kraft pulp mills, but it also causes problems. The total pulp production of many mills is limited by the recovery furnace capacity, which cannot easily be increased. The furnace is one of the largest sources of air pollution (as reduced sulfur compounds) in the kraft pulp mill.

  20. Comprehensive Numerical Modeling of the Blast Furnace Ironmaking Process

    Science.gov (United States)

    Zhou, Chenn; Tang, Guangwu; Wang, Jichao; Fu, Dong; Okosun, Tyamo; Silaen, Armin; Wu, Bin

    2016-05-01

    Blast furnaces are counter-current chemical reactors, widely utilized in the ironmaking industry. Hot reduction gases injected from lower regions of the furnace ascend, reacting with the descending burden. Through this reaction process, iron ore is reduced into liquid iron that is tapped from the furnace hearth. Due to the extremely harsh environment inside the blast furnace, it is difficult to measure or observe internal phenomena during operation. Through the collaboration between steel companies and the Center for Innovation through Visualization and Simulation, multiple computational fluid dynamics (CFD) models have been developed to simulate the complex multiphase reacting flow in the three regions of the furnace, the shaft, the raceway, and the hearth. The models have been used effectively to troubleshoot and optimize blast furnace operations. In addition, the CFD models have been integrated with virtual reality. An interactive virtual blast furnace has been developed for training purpose. This paper summarizes the developments and applications of blast furnace CFD models and the virtual blast furnace.

  1. Arc of opportunity.

    Science.gov (United States)

    Delaney, Adam Vai

    2011-07-01

    Born in Port Moresby, Papua New Guinea, the author had a 20 year career in diplomacy, political affairs, and development policy analysis at the Pacific Islands Forum, the United Nations in New York; the Prime Minister's Department in Papua New Guinea (PNG) and in the Foreign Ministry of PNG. He has also been involved in theatre for over a decade in PNG, and participated in a three-month program at the Eugene O'Neill Theatre Center in Connecticut, USA. He is currently the Business Development Manager at the Torres Strait Regional Authority (Commonwealth) on Thursday Island. Since 1975 the Australian government's overseas development policy has supported various sectoral programs in its neighbouring countries, in particular Papua New Guinea and the Solomon Islands. The "creative" field has not been prominent in this strategy. While natural resources and the sports sectors have gained much greater attention, in terms of being viable international commercial enterprises, the arts, have remained stagnant. In this paper the need for joint programs genuinely supporting "wellbeing" and promoting social enterprise throughout the "arc of opportunity" is described to harness Melanesian creativity to compete successfully in world-markets, starting with penetration of the largest economy at its door-step: Australia.

  2. Type the title of your paper here Effect of the focused light from the xenon arc lamp on the surface tension of the molten enamel

    Science.gov (United States)

    Aleutdinov, A. D.; Ghyngazov, S. A.; Mylnikova, T. S.; Aleutdinov, K. A.

    2016-02-01

    The effect of exposure to the focused light from the xenon arc lamp on the surface tension of molten enamels was studied with a designed light beam setup as compared to that observed in conventional heating in a resistance furnace. The objects under investigation were enamels No. 261, UES-200 and UES-300. The power density of the light beam was varied in the range of (30-80) W/cm2. When exposed to light, the surface tension is shown to be an order of magnitude lower than that obtained in conventional furnace heating.

  3. STUDY ON THE PRESSURE IN PLASMA ARC

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The axial pressure in plasma arc is measured under different conditions. The effects of the parameters, such as welding current, plasma gas flow rate, electrode setback and arc length, on the pressure in plasma arc are investigated and quantitative analyzed to explain the relationship between the quality of weld and the matching of parameters in plasma arc welding process.

  4. Molten metal holder furnace and casting system incorporating the molten metal holder furnace

    Science.gov (United States)

    Kinosz, Michael J.; Meyer, Thomas N.

    2003-02-11

    A bottom heated holder furnace (12) for containing a supply of molten metal includes a storage vessel (30) having sidewalls (32) and a bottom wall (34) defining a molten metal receiving chamber (36). A furnace insulating layer (42) lines the molten metal receiving chamber (36). A thermally conductive heat exchanger block (54) is located at the bottom of the molten metal receiving chamber (36) for heating the supply of molten metal. The heat exchanger block (54) includes a bottom face (65), side faces (66), and a top face (67). The heat exchanger block (54) includes a plurality of electrical heaters (70) extending therein and projecting outward from at least one of the faces of the heat exchanger block (54), and further extending through the furnace insulating layer (42) and one of the sidewalls (32) of the storage vessel (30) for connection to a source of electrical power. A sealing layer (50) covers the bottom face (65) and side faces (66) of the heat exchanger block (54) such that the heat exchanger block (54) is substantially separated from contact with the furnace insulating layer (42).

  5. Oil injection into the blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Dongsheng Liao; Mannila, P.; Haerkki, J.

    1997-12-31

    Fuel injection techniques have been extensively used in the commercial blast furnaces, a number of publications concerning the fuels injection have been reported. This present report only summarizes the study achievements of oil injection due to the research need the of authors, it includes the following parts: First, the background and the reasons reducing coke rate of oil injection are analyzed. Reducing coke rate and decreasing the ironmaking costs are the main deriving forces, the contents of C, H and ash are direct reasons reducing coke rate. It was also found that oil injection had great effects on the state of blast furnace, it made operation stable, center gas flow develop fully, pressure drop increase, descent speed of burden materials decrease and generation of thermal stagnation phenomena, the quality of iron was improved. Based on these effects, as an ideal mean, oil injection was often used to adjust the state of blast furnace. Secondly, combustion behavior of oil in the raceway and tuyere are discussed. The distribution of gas content was greatly changed, the location of CO, H{sub 2} generation was near the tuyere; the temperature peak shifts from near the raceway boundary to the tuyere. Oxygen concentration and blast velocity were two important factors, it was found that increasing excess oxygen ratio 0.9 to 1.3, the combustion time of oil decreases 0.5 msec, an increase of the blast velocity results in increasing the flame length. In addition, the nozzle position and oil rate had large effects on the combustion of oil. Based on these results, the limit of oil injection is also discussed, soot formation is the main reason limiting to further increase oil injection rate, it was viewed that there were three types of soot which were generated under blast furnace operating conditions. The reason generating soot is the incomplete conversion of the fuel. Finally, three methods improving combustion of oil in the raceway are given: Improvement of oil

  6. Pyrometric temperature measurements in the solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Tschudi, H.-R; Mueller, Ch.

    2000-07-01

    Surface temperatures are key parameters in many applications of concentrated solar radiation. Pyrometric temperature determination is here hampered by the reflected solar radiation. Two approaches to solve this problem were experimentally tested with the TREMPER reactor in the solar furnace at PSI: the flash assisted multiwavelength pyrometry (FAMP) developed at PSI and a so called 'solar-blind' pyrometer developed by IMPAC Electronic GmbH in Frankfurt, Germany, in collaboration with PSI. Performance, advantages and disadvantages of the two different pyrometers are reported and discussed. (authors)

  7. Vacuum Furnace - Integrated "Sub zero" Treatment

    Institute of Scientific and Technical Information of China (English)

    B. Zieger; Hubert Schulte

    2004-01-01

    The vacuum heat treatment with overpressure gas quenching is more and more accepted due to considerable advantages compared to the traditional oil and salt bath processes. Continuous further developments and new concepts like multi-directional cooling systems, a separate quenching chamber and "sub zero" systems lead towards an oxidation free and low distortion vacuum heat treatment for a broad range of parts and materials. Short and energy saving processes guarantee a high economic efficiency and environmental compatibility.The "sub zero" system which is integrated into the standard vacuum furnace achieves a heat treatment result with a high conversion of retained austenite in fully automatic hardening and tempering processes.

  8. Advanced steel reheat furnaces: Research and development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Q.; Koppang, R.; Maly, P.; Moyeda, D. [Energy and Environmental Research Corp., Irvine, CA (United States); Li, X. [Air Products and Chemicals, Inc., Allentown, PA (United States)

    1999-01-14

    The purpose of this report is to present the results of two phases of a three-phase project to develop and evaluate an Advanced Steel Reheat Furnace (SSRF) concept which incorporates two proven and commercialized technologies, oxy-fuel enriched air (OEA) combustion and gas reburning (GR). The combined technologies aim to improve furnace productivity with higher flame radiant heat transfer in the heating zones of a steel reheat furnace while controlling potentially higher NOx emissions from these zones. The project was conducted under a contract sponsored by the Department of Energy (DOE). Specifically, this report summarizes the results of a modeling study and an experimental study to define and evaluate the issues which affect the integration and performance of the combined technologies. Section 2.0 of the report describes the technical approach uses in the development and evaluation of the advanced steel reheat furnace. Section 3.0 presents results of the modeling study applied to a model steel furnace. Experimental validation of the modeling results obtained from EER`s Fuel Evaluation Facility (FEF) pilot-scale furnace discussed in Section 4.0. Section 5.0 provides an economic evaluation on the cost effectiveness of the advanced reheat furnace concept. Section 6.0 concludes the report with recommendations on the applicability of the combined technologies of steel reheat furnaces.

  9. Reduction Mechanism of Chromite Ore in Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    LI Yi-wei; DING Wei-zhong; LU Xiong-gang; XU Kuang-di

    2004-01-01

    The structural changes and reduction degree of chromite ore in blast furnace were studied by optical micrograph analysis, scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDXA). The smelting reduction mechanism of chromite in blast furnace was primarily discussed.

  10. Open fireplace furnace as an adequate heating system

    Energy Technology Data Exchange (ETDEWEB)

    Terbrack, E.

    The fireplace furnace is a furnace for the open fireplace. It is connected to the existing fuel-oil or gas central heating and is used for house heating and warm water preparation when the fire in the fireplace is on. It combines the romanticism of the open fireplace with the necessity of saving fuel oil and gas, ensuring heat supply.

  11. DEMONSTRATION BULLETIN: CYCLONE FURNACE SOIL VITRI- FICATION TECHNOLOGY - BABCOCK & WILCOX

    Science.gov (United States)

    Babcock and Wilcox's (B&W) cyclone furnace is an innovative thermal technology which may offer advantages in treating soils containing organics, heavy metals, and/or radionuclide contaminants. The furnace used in the SITE demonstration was a 4- to 6-million Btu/hr pilot system....

  12. C AND M BOTTOM LOADING FURNACE TEST DATA

    Energy Technology Data Exchange (ETDEWEB)

    Lemonds, D

    2005-08-01

    The test was performed to determine the response of the HBL Phase III Glovebox during C&M Bottom Loading Furnace operations. In addition the data maybe used to benchmark a heat transfer model of the HBL Phase III Glovebox and Furnace.

  13. A New Mathematical Simulation Approach for Thermal Cracking Furnace Studies

    Institute of Scientific and Technical Information of China (English)

    LanXingying; XuChunming; GaoJinsen; ZhangHongmei

    2005-01-01

    Thermal cracking of hydrocarbons for olefin production is normally carried out in long reactor tubes suspended in a large gas fired furnace. In this paper, a coupled furnace-reactor mathematical model based on a computational fluid dynamics (CFD) technique is developed to simulate the complex fluid dynamics phenomena in the thermal cracking furnace. The model includes mass transfer, momentum transfer, and heat transfer, as well as thermal cracking reactions, fuel combustion and radiative heat transfer. The rationality and reliability of the mathematical model is confirmed by the approximate agreement of predicted data and industrial data. The coupled furnace-reactor simulation revealed the details of both the transfer and reaction processes taking place in the thermal cracking furnace. The results indicate highly nonuniform distribution of the flue-gas velocity, concentration and temperature in the furnace, which cause nonuniform distribution of tube skin temperature and heat flux of the reactor tubes. Profiles of oil-gas velocity,pressure, temperature and product yields in the lengthwise direction of the reactor tube are obtained. Furthermore, in the radial direction steep velocity and temperature gradients and relatively slight gradients of species concentration are found.In conclusion, the model can provide more information on the fluid dynamics and reaction behavior in the thermal cracking furnace, and guidance for the design and improvement of thermal cracking furnaces.

  14. Estimation of slagging in furnaces; Kuonaavuuden ennustaminen kivihiilen poelypoltossa

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, T.; Jaeaeskelaeinen, K.; Oeini, J.; Koskiahde, A.; Jokiniemi, J.; Pyykkoenen, J. [Imatran Voima Oy, Vantaa (Finland)

    1997-10-01

    Understanding and estimation of slagging in furnaces is essential in the design of new power plants with high steam values or in modifications like low-NO{sub x} retrofits in existing furnaces. Major slagging yields poor efficiency, difficult operation and high maintenance costs of the plant. The aim of the project is to develop a computational model for slagging in pulverized coal combustion. The model is based on Computer Controlled Scanning Electron Microscopy (CCSEM) analysis of mineral composition of the coal and physical models for behaviour of minerals inside a furnace. The analyzed mineral particles are classified to five composition classes and distributed to calculational coal particles if internal minerals of coal. The calculational coal particles and the external minerals are traced in the furnace to find out the behaviour of minerals inside the furnace. If the particle tracing indicates that the particle hits the heat transfer surface of the furnace the viscosity of the particle is determined to see if particle is sticky. The model will be implemented to 3D computational fluid dynamics based furnace simulation environment Ardemus which predicts the fluid dynamics, heat transfer and combustion in a furnace. (orig.)

  15. CHARCOAL PACKED FURNACE FOR LOW-TECH CHARRING OF BONE

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A low-tech furnace for charring of raw bone using char coal is developed and tested. The furnace consists of a standard oil drum, fitted with simple materials as available in every market in small towns in developing counties. 80 kg of raw bone and 6 kg of charcoal are used for production of 50 k...

  16. Glass Furnace Combustion and Melting Research Facility.

    Energy Technology Data Exchange (ETDEWEB)

    Connors, John J. (PPG Industries, Inc., Pittsburgh, PA); McConnell, John F. (JFM Consulting, Inc., Pittsburgh, PA); Henry, Vincent I. (Henry Technology Solutions, LLC, Ann Arbor, MI); MacDonald, Blake A.; Gallagher, Robert J.; Field, William B. (Lilja Corp., Livermore, CA); Walsh, Peter M.; Simmons, Michael C. (Lilja Corp., Livermore, CA); Adams, Michael E. (Lilja Corp., Rochester, NY); Leadbetter, James M. (A.C. Leadbetter and Son, Inc., Toledo, OH); Tomasewski, Jack W. (A.C. Leadbetter and Son, Inc., Toledo, OH); Operacz, Walter J. (A.C. Leadbetter and Son, Inc., Toledo, OH); Houf, William G.; Davis, James W. (A.C. Leadbetter and Son, Inc., Toledo, OH); Marvin, Bart G. (A.C. Leadbetter and Son, Inc., Toledo, OH); Gunner, Bruce E. (A.C. Leadbetter and Son, Inc., Toledo, OH); Farrell, Rick G. (A.C. Leadbetter and Son, Inc., Toledo, OH); Bivins, David P. (PPG Industries, Inc., Pittsburgh, PA); Curtis, Warren (PPG Industries, Inc., Pittsburgh, PA); Harris, James E. (PPG Industries, Inc., Pittsburgh, PA)

    2004-08-01

    The need for a Combustion and Melting Research Facility focused on the solution of glass manufacturing problems common to all segments of the glass industry was given high priority in the earliest version of the Glass Industry Technology Roadmap (Eisenhauer et al., 1997). Visteon Glass Systems and, later, PPG Industries proposed to meet this requirement, in partnership with the DOE/OIT Glass Program and Sandia National Laboratories, by designing and building a research furnace equipped with state-of-the-art diagnostics in the DOE Combustion Research Facility located at the Sandia site in Livermore, CA. Input on the configuration and objectives of the facility was sought from the entire industry by a variety of routes: (1) through a survey distributed to industry leaders by GMIC, (2) by conducting an open workshop following the OIT Glass Industry Project Review in September 1999, (3) from discussions with numerous glass engineers, scientists, and executives, and (4) during visits to glass manufacturing plants and research centers. The recommendations from industry were that the melting tank be made large enough to reproduce the essential processes and features of industrial furnaces yet flexible enough to be operated in as many as possible of the configurations found in industry as well as in ways never before attempted in practice. Realization of these objectives, while still providing access to the glass bath and combustion space for optical diagnostics and measurements using conventional probes, was the principal challenge in the development of the tank furnace design. The present report describes a facility having the requirements identified as important by members of the glass industry and equipped to do the work that the industry recommended should be the focus of research. The intent is that the laboratory would be available to U.S. glass manufacturers for collaboration with Sandia scientists and engineers on both precompetitive basic research and the

  17. The Advanced Automated Directional Solidification Furnace

    Science.gov (United States)

    Gillies, D. C.; Reeves, F. A.; Jeter, L. B.; Sledd, J. D.; Cole, J. M.; Lehoczky, S. L.

    1996-01-01

    The Advanced Automated Directional Solidification Furnace (AADSF) is a five zone tubular furnace designed for Bridgman-Stockbarger, other techniques of crystal growth involving multiple temperature zones such as vapor transport experiments and other materials science experiments. The five zones are primarily designed to produce uniform hot and cold temperature regions separated by an adiabatic region constructed of a heat extraction plate and an insert to reduce radiation from the hot to the cold zone. The hot and cold zone temperatures are designed to reach 1600 C and 1100 C, respectively. AADSF operates on a Multi-Purpose Experiment Support Structure (MPESS) within the cargo bay of the Space Shuttle on the United States Microgravity Payload (USMP) missions. Two successful flights, both employing the directional solidification or Bridgman Stockbarger technique for crystal growth have been made, and crystals of HgCdTe and PbSnTe grown in microgravity have been produced on USMP-2 and USMP-3, respectively. The addition of a Sample Exchange Mechanism (SEM) will enable three different samples to be processed on future flights including the USMP-4 mission.

  18. Arsenic immobilization of Teniente furnace dust

    Energy Technology Data Exchange (ETDEWEB)

    Ichimura, R. [Japan Oil, Gas, and Metals National Corp., Kawasaki (Japan); Tateiwa, H. [Mitsui Mining and Smelting Co. Ltd., Saitama (Japan); Almendares, C. [Centro de Investigacion Minera y Metalurgica, Santiago (Chile); Sanchez, G. [CODELCO, Santiago (Chile). Division Ventanas

    2007-07-01

    A 5-year joint Japanese-Chilean project to modify the treatment of furnace dust from a converter in Chile producing harmful amounts of arsenic and lead was described. A pilot plant was constructed to evaluate the method's commercialization potential. Flue dust was recovered by a dust collector installed to capture suspended dust generated by the smelting furnace. Arsenic content was approximately 15 per cent. Ninety per cent of the arsenic was then liquidated to lixivia and dissolved by leaching flue dust with sulphuric acid. The leaching rate decreased when flue dust had a high content of residual sulfide ore. A flotation device was then incorporated in the treatment process in order to increase the copper recovery rate. A solvent recovery process was then adopted to recover the copper and zinc contained in the solution after the arsenic recovery. An economic evaluation of the process indicated that efforts should be made to improve the efficiency of the dust treatment method. 5 refs., 6 tabs., 10 figs.

  19. Durability of Alkali Activated Blast Furnace Slag

    Science.gov (United States)

    Ellis, K.; Alharbi, N.; Matheu, P. S.; Varela, B.; Hailstone, R.

    2015-11-01

    The alkali activation of blast furnace slag has the potential to reduce the environmental impact of cementitious materials and to be applied in geographic zones where weather is a factor that negatively affects performance of materials based on Ordinary Portland Cement. The scientific literature provides many examples of alkali activated slag with high compressive strengths; however research into the durability and resistance to aggressive environments is still necessary for applications in harsh weather conditions. In this study two design mixes of blast furnace slag with mine tailings were activated with a potassium based solution. The design mixes were characterized by scanning electron microscopy, BET analysis and compressive strength testing. Freeze-thaw testing up to 100 freeze-thaw cycles was performed in 10% road salt solution. Our findings included compressive strength of up to 100 MPa after 28 days of curing and 120 MPa after freeze-thaw testing. The relationship between pore size, compressive strength, and compressive strength after freeze-thaw was explored.

  20. Mercury in dumped blast furnace sludge.

    Science.gov (United States)

    Földi, Corinna; Dohrmann, Reiner; Mansfeldt, Tim

    2014-03-01

    Blast furnace sludge (BFS) is a waste generated in the production of pig iron and was dumped in sedimentation ponds. Sixty-five samples from seven BFS locations in Europe were investigated regarding the toxic element mercury (Hg) for the first time. The charge material of the blast furnace operations revealed Hg contents from 0.015 to 0.097mgkg(-1). In comparison, the Hg content of BFS varied between 0.006 and 20.8mgkg(-1) with a median of 1.63mgkg(-1), which indicates enrichment with Hg. For one site with a larger sample set (n=31), Hg showed a stronger correlation with the total non-calcareous carbon (C) including coke and graphite (r=0.695; n=31; p<0.001). It can be assumed that these C-rich compounds are hosting phases for Hg. The solubility of Hg was rather low and did not exceed 0.43% of total Hg. The correlation between the total Hg concentration and total amount of NH4NO3-soluble Hg was relatively poor (r=0.496; n=27; p=0.008) indicating varying hazard potentials of the different BFS. Finally, BFS is a mercury-containing waste and dumped BFS should be regarded as potentially mercury-contaminated sites.

  1. Considerations for Scale-Up of Ferronickel Electric Smelting Furnaces

    Science.gov (United States)

    Hundermark, R. J.; Nelson, L. R.

    2017-02-01

    In ferronickel smelting, the selective carbothermic reduction of calcined nickel laterite ores in large electric furnaces yields a crude ferronickel product. The optimal process for nickel laterite smelting requires a fine balance between the metallurgical requirements of the process (feed composition, nickel recovery, energy consumption, product quality) and the capabilities of the feeding, tapping and off-gas systems, and especially of the furnace crucible and electrical system. The scale-up of nickel laterite smelting operations over the last 50 years has seen a tenfold increase in furnace power input. Furnace operations within the industry are examined to identify common trends and some new metrics are proposed which incorporate the combination of electrode power densities and the impact of alloy nickel grade on gas generation rates, and hence local electrode gas fluxes, which may impact on future scale-up of ferronickel furnaces.

  2. Effect of furnace atmosphere on E-glass foaming

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Sang; Dutton, Bryan C.; Hrma, Pavel R.; Pilon, Laurent

    2006-12-01

    The effect of furnace atmosphere on E-glass foaming generated in crucible has been studied with a specific goal to understand the impact of increased water content on foaming in oxy-fired furnaces. E-glass foams were generated in a fused-quartz crucible located in a quartz window furnace equipped with video recording. The present study showed that humidity in the furnace atmosphere destabilizes foam, while other gases have little effect on foam stability. This study suggests that the higher foaming in oxy-fired furnace compared to air-fired is caused by the effect of water on early sulfate decomposition, promoting more efficient refining gas generation from sulfate (known as “dilution effect”).

  3. Current Trend in Furnace Technology in the Melting Industries

    Directory of Open Access Journals (Sweden)

    O.A. Ighodalo

    2011-06-01

    Full Text Available The aim of this study is to presents some of the current trend in Furnace technology as it pertains to the melting industries. Furnaces are applied in various industries for material processing. Large amounts of energy are usually consumed in the melting industries. The current trend in furnace technology is towards energy conservation, enhanced efficiency and productivity. The reduction of pollutant emissions are also taken into consideration due to their environmental impact. The various materials and processes for furnaces are discussed. The various strategies being employed towards furnace energy conservation, efficiency and productivity, and reduction of pollutant emissions are also discussed. Such strategies include the use of better fuel types such as natural gas; improved insulation and refractory materials; advanced burner designs such as high velocity, regenerative and recuperative burners; new combustion technologies such as air and fuel staging, flue gas recirculation technique. Mathematical modeling is also being employed for analysis and design purpose.

  4. High pressure neon arc lamp

    Science.gov (United States)

    Sze, Robert C.; Bigio, Irving J.

    2003-07-15

    A high pressure neon arc lamp and method of using the same for photodynamic therapies is provided. The high pressure neon arc lamp includes a housing that encloses a quantity of neon gas pressurized to about 500 Torr to about 22,000 Torr. At each end of the housing the lamp is connected by electrodes and wires to a pulse generator. The pulse generator generates an initial pulse voltage to breakdown the impedance of the neon gas. Then the pulse generator delivers a current through the neon gas to create an electrical arc that emits light having wavelengths from about 620 nanometers to about 645 nanometers. A method for activating a photosensitizer is provided. Initially, a photosensitizer is administered to a patient and allowed time to be absorbed into target cells. Then the high pressure neon arc lamp is used to illuminate the target cells with red light having wavelengths from about 620 nanometers to about 645 nanometers. The red light activates the photosensitizers to start a chain reaction that may involve oxygen free radicals to destroy the target cells. In this manner, a high pressure neon arc lamp that is inexpensive and efficiently generates red light useful in photodynamic therapy is provided.

  5. 双冷却系统在一次封排炉中的应用%Application of the Double Cooling System on the Seal-Welding and Exhausting Furnace

    Institute of Scientific and Technical Information of China (English)

    孙海勇; 姚栓科; 许兆祥

    2011-01-01

    一次封排炉是目前生产真空灭弧室的关键设备.在工作过程中,设备的炉膛壳体部分和扩散泵均需要冷却.本文以实例介绍了双冷却系统的设计及其在一次封排炉中的应用情况.%Seal-Welding and Exhausting Furnace is the key equipment to produce the vacuum arc extinguishing chamber. In the work process, both the furnace chamber shell and the diffusion pump need to be cooled. This paper introduces the design of double cooling system and its application on the Seal-Welding and Exhausting Furnace with example.

  6. Gas Tungsten Arc Welding and Plasma Arc Cutting. Teacher Edition.

    Science.gov (United States)

    Fortney, Clarence; And Others

    This welding curriculum guide treats two topics in detail: the care of tungsten electrodes and the entire concept of contamination control and the hafnium electrode and its importance in dual-air cutting systems that use compressed shop air for plasma arc cutting activities. The guide contains three units of instruction that cover the following…

  7. Thermodynamic modeling of lead blast furnace

    Institute of Scientific and Technical Information of China (English)

    TAN Peng-fu

    2005-01-01

    A thermodynamic model was developed to predict the distribution behavior of Cu,Fe,S,O,Pb,Zn,As,and the heat balance in a lead blast furnace.The modeling results are validated by the plant data of a lead smelter in Kazakhstan.The model can be used to predict any set of controllable process parameters such as feed composition,smelting temperature,degree of oxygen enrichment and volume of oxygen-enriched air.The effects of the blast air,industrial oxygen,and coke charge on the distribution of Cu,Fe,S,O,Pb,Zn,As,the heat balance,and the lead loss in slag,were presented and discussed.

  8. PERFORMANCE TESTING AND ANALYSIS OF CUPOLA FURNACE

    Directory of Open Access Journals (Sweden)

    PROF.HEMANT R. BHAGAT-PATIL

    2013-05-01

    Full Text Available In today’s industrial scenario huge losses/wastage occur in the manufacturing shop floor and foundry industries. The efficiency of any foundry largely depends on the efficiency of the melting process amulti-step operation where the metal is heated, treated, alloyed, and transported into die or mold cavities to form a casting. In this paper we represents the performance testing and analysis of Cupola Furnace, and reduces the problems occurs to give the best results. Our main focus in this work is to improve continuous working hours,reducing preparation time, reducing losses in melting, reducing slag formation and to increase the combustion efficiency of coke and overall productivity and to improve the quality and Mechanical properties of steel using Cupola.

  9. CFD Simulation on Ethylene Furnace Reactor Tubes

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Different mathematical models for ethylene furnace reactor tubes were reviewed. On the basis of these models a new mathematical simulation approach for reactor tubes based on computational fluid dynamics (CFD) technique was presented. This approach took the flow, heat transfer, mass transfer and thermal cracking reactions in the reactor tubes into consideration. The coupled reactor model was solved with the SIMPLE algorithm. Some detailed information about the flow field, temperature field and concentration distribution in the reactor tubes was obtained, revealing the basic characteristics of the hydrodynamic phenomena and reaction behavior in the reactor tubes. The CFD approach provides the necessary information for conclusive decisions regarding the production optimization, the design and improvement of reactor tubes, and the new techniques implementation.

  10. FAILURES AND THE LIFE OF FURNACE TUBES

    Institute of Scientific and Technical Information of China (English)

    F.Z.Shen; Y.Ding; D.M.Hou; Z.P.Ning; Y.Lü; T.B.Dong; A.R.Tuohuti

    2004-01-01

    It is showed after the furnace tubes serviced for 8-10 years that the density of damage in the HAZ (heat affected zone) of the weld has higher than in parent metals, though the depth of damage is not equal to. By the test of creep crack growth, it is also acquired that under same mechanic parameter C* (t), the rate of creep crack growth in the HAZ is more than twice as fast as in parent metals. Two mechanisms (overheating and thermal shock) of failure occurred in an accident are presented. The stress of thermal shock is analyzed, in which the change of the elasticity modulus with the radius ET = f(r) is considered. Based on it, the safety region of the thermal shock is obtained. Finally, two sets of curves for the safe life are suggested which can facilitate to estimate the remaining life of HK-40 or HP-Nb tubes by their creep rupture data.

  11. Torrefied biomasses in a drop tube furnace to evaluate their utility in blast furnaces.

    Science.gov (United States)

    Chen, Wei-Hsin; Du, Shan-Wen; Tsai, Chien-Hsiung; Wang, Zhen-Yu

    2012-05-01

    Torrefaction and burning characteristics of bamboo, oil palm, rice husk, bagasse, and Madagascar almond were studied and compared with a high-volatile bituminous coal using a drop tube furnace to evaluate the potential of biomass consumed in blast furnaces. Torrefaction at 250 and 300°C for 1h duration was carried out. Analysis using the ash tracer method indicated that the extent of atomic carbon reduction in the biomasses was less than that of atomic hydrogen and oxygen. Torrefaction also lowered the sulfur content in bamboo and oil palm over 33%. An examination of the R-factor and burnout of the samples suggests that more volatiles were released and a higher burnout was achieved with raw and torrefied biomasses at 250°C than at 300°C; however, torrefaction at 300°C is a feasible operating condition to transform biomass into a solid fuel resembling a high-volatile bituminous coal used for blast furnaces.

  12. An update on blast furnace granular coal injection

    Energy Technology Data Exchange (ETDEWEB)

    Hill, D.G. [Bethlehem Steel Corp., Burns Harbor, IN (United States); Strayer, T.J.; Bouman, R.W. [Bethlehem Steel Corp., PA (United States)

    1997-12-31

    A blast furnace coal injection system has been constructed and is being used on the furnace at the Burns Harbor Division of Bethlehem Steel. The injection system was designed to deliver both granular (coarse) and pulverized (fine) coal. Construction was completed on schedule in early 1995. Coal injection rates on the two Burns Harbor furnaces were increased throughout 1995 and was over 200 lbs/ton on C furnace in September. The injection rate on C furnace reached 270 lbs/ton by mid-1996. A comparison of high volatile and low volatile coals as injectants shows that low volatile coal replaces more coke and results in a better blast furnace operation. The replacement ratio with low volatile coal is 0.96 lbs coke per pound of coal. A major conclusion of the work to date is that granular coal injection performs very well in large blast furnaces. Future testing will include a processed sub-bituminous coal, a high ash coal and a direct comparison of granular versus pulverized coal injection.

  13. RESEARCH ON THE DYNAMIC MATHEMATICAL MODELOF REHEATING FURNACE

    Institute of Scientific and Technical Information of China (English)

    徐立云; 张斌; 王景成; 邵惠鹤

    2001-01-01

    This paper presented a dynamical mathematical model for reheating furnace based on energy balance, which consists of three submodels. With the inputting parameters, adopting the finite difference technique, not only the combustion gas temperature but also the temperature distribution of slabs in the furnace can be predicated. The dynamical mathematical model is the base for the further control and it also can be treated as a simulator of a reheating furnace, optimal and advanced controlling strategies can be applied based on the dynamical model.

  14. DEVELOPMENT OF A FURNACE TO FABRICATE SILICON SOLAR CELLS

    OpenAIRE

    Sérgio Boscato Garcia; Adriano Moehlecke; Izete Zanesco

    2012-01-01

    Solar cell world market had an exponential growth in the last decade and nowadays it continues in expansion. To produce solar cells, dopants need to be introduced into the crystalline silicon wafer in order to form the pn junction. This process is carried out in diffusion furnaces. The aim of this paper is to present the development of a compact diffusion furnace to process up to 156 mm × 156 mm silicon wafers and to operate at temperature up to 1100°C. The furnace is automated an...

  15. A Possible Macroscopic-Photo-Catalysis Mechanism in Solar Furnace

    Science.gov (United States)

    Ho, Tsohsiu; Qing, Cheng-Rui; Chen, Ying-Tian

    2011-05-01

    Based on the experimental results of Chen et al. to use the solar furnace and medium frequency induction furnace to extract boron impurity from metallurgical silicon, we propose a strong radiation catalysis mechanism to explain the difference of reaction rates in these two furnaces. The postulate assuming the photons striking on the material not only increase the thermal energy of the molecules of reactants but also lower down the energy barrier of the reaction to speed up the chemical reaction. It is believed the photon catalysis mechanism is universal in most of high temperature chemical reactions and looking forward to more evidences for the postulate proposed in this article.

  16. A Possible Macroscopic-Photo-Catalysis Mechanism in Solar Furnace

    Institute of Scientific and Technical Information of China (English)

    HO Tsohsiu; QING Cheng-Rui; CHEN Ying-Tian

    2011-01-01

    Based on the experimental results of Chen et al.to use the solar furnace and medium frequency induction furnace to extract boron impurity from metallurgical silicon, we propose a strong radiation catalysis mechanism to explain the difference of reaction rates in these two furnaces.The postulate assuming the photons striking on the material not only increase the thermal energy of the molecules of reactants but also lower down the energy barrier of the reaction to speed up the chemical reaction.It is believed the photon catalysis mechanism is universall in most of high temperature chemical reactions and looking forward to more evidences for the postulate proposed in this article.

  17. Application study of complex control algorithm for regenerative furnace temperature

    Institute of Scientific and Technical Information of China (English)

    Lusheng GE

    2004-01-01

    Altemative switch combustion mode of air and gas is adopted on the two sides of the regenerative furnace, its temperature is in uncontrolled state in the switching process and the switch period is generally 3 ~ 5 min. Thus, the conventional bi-cross limited combustion control method is no longer applicable to the object. This paper makes use of neutral network algorithm to adjust the static operating point. On this basis, fuzzy control strategy is used for the furnace temperature control. The actual application result shows that the control strategy is effective to solve the problem of the combustion control for regenerative furnace.

  18. In-service helium leak testing of vacuum furnace

    Science.gov (United States)

    Ahmad, Anis; Tripathi, S. K.; Sawant, P. S.; Mukharjee, D.; Shah, B. K.

    2012-11-01

    Helium leak detection of vacuum furnaces and equipments used for processing of nuclear material is generally carried out by utilizing vacuum spray technique. In this technique helium leak detector is connected to the furnace, back ground reading is noted and helium gas is sprayed on all the suspected joints. Any increase in back ground is noted as leak signal. Processing of Zirconium alloy cladded fuel pins is carried out in vacuum furnace of about 3 meter length and 500 mm inside diameter. Furnace is connected with two numbers of rotary vacuum pump and one number of diffusion pump for creating vacuum (1 × 10-6 torr) inside the furnace. It is desirable that furnace should have good vacuum and best possible leak tightness during dynamic and static vacuum. During dynamic vacuum at higher temperature although required vacuum is achieved the furnace may have fine leakage through which air may enter and cause oxidation of clad tube leading to change in its coloration. This change in coloration will cause rejection of fuel element. Such fine leakages may not be reflected in the dynamic vacuum of the system at high temperature. During trial run change in coloration of outside surface of clad tube was observed although dynamic vacuum of the furnace was in the range of 1×10-6 torr range. To eliminate such possibilities of oxidation due to fine leakages in the system, it was decided to carry out in-service leak testing of the furnace. Helium leak testing of the furnace was carried out by using vacuum spray method and leaks observed were repaired and furnace was retested to ensure the leak tightness. The in-service helium leak testing of the furnace helped in maintaining its leak tightness during service under dynamic vacuum and prevent oxidation of fuel element. This paper describes the techniques of in- service helium leak testing, it's importance for detection of fine leak under dynamic vacuum and discusses details of the testing method and result obtained.

  19. Hooded arc ion-source

    CERN Multimedia

    1972-01-01

    The positioning system for the hooded arc ion-source, shown prior to mounting, consists of four excentric shafts to locate the ion-source and central electrodes. It will be placed on the axis of the SC and introduced into the vacuum tank via the air locks visible in the foreground.

  20. Vacuum Gas Tungsten Arc Welding

    Science.gov (United States)

    Weeks, J. L.; Todd, D. T.; Wooten, J. R.

    1997-01-01

    A two-year program investigated vacuum gas tungsten arc welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. After a vacuum chamber and GTAW power supply were modified, several difficult-to-weld materials were studied and key parameters developed. Finally, Incoloy 903 weld overlays were produced without microfissures.

  1. Rotating Drive for Electrical-Arc Machining

    Science.gov (United States)

    Fransen, C. D.

    1986-01-01

    Rotating drive improves quality of holes made by electrical-arc machining. Mechanism (Uni-tek, rotary head, or equivalent) attached to electrical-arc system. Drive rotates electrode as though it were mechanical drill, while an arc disintegrates metal in workpiece, thereby creating hole. Rotating electrode method often used in electric-discharge machining. NASA innovation is application of technique to electrical-arc machining.

  2. STRUVE arc and EUPOS® stations

    Science.gov (United States)

    Lasmane, Ieva; Kaminskis, Janis; Balodis, Janis; Haritonova, Diana

    2013-04-01

    The Struve Geodetic Arc was developed in Years 1816 to 1855, 200 years ago. Historic information on the points of the Struve Geodetic Arc are included in the UNESCO World Heritage list in 2005. Nevertheless, the sites of many points are still not identified nor included in the data bases nowadays. Originally STRUVE arc consisted of 258 main triangles with 265 triangulation points. Currently 34 of the original station points are identified and included in the in the UNESCO World Heritage list. identified original measurement points of the Meridian Arc are located in Sweden (7 points), Norway (15), Finland (83), Russia (1), Estonia (22), Latvia (16), Lithuania (18), Belorussia (28), Ukraine (59) and Moldova (27). In Year 2002 was initiated another large coverage project - European Position Determination System "EUPOS®". Currently there are about 400 continuously operating GNSS (Global Navigation Satellite Systems) stations covering EU countries Estonia, Latvia, Lithuania, Poland, Czech Republic, Slovakia, Hungary, Bulgaria, Romania and East European countries Ukraine and Moldavia. EUPOS® network is a ground based GNSS augmentation system widely used for geodesy, land surveying, geophysics and navigation. It gives the opportunity for fast and accurate position determination never available before. It is an honorable task to use the EUPOS® system for research of the Struve triangulation former sites. Projects with Struve arc can popularize geodesy, geo-information and its meaning in nowadays GIS and GNSS systems. Struve Arc and its points is unique cooperation cross-border object which deserve special attention because of their natural beauty and historical value for mankind. GNSS in geodesy discovers a powerful tool for the verification and validation of the height values of geodetic leveling benchmarks established historically almost 200 years ago. The differential GNSS and RTK methods appear very useful to identify vertical displacement of landscape by means of

  3. A Survey Study of the Blast Furnace at Kuangshan Village Using 3D Laser Scanning

    Science.gov (United States)

    Wang, Jin; Huang, Xing; Qian, Wei

    2017-01-01

    The blast furnace from the Northern Song Dynasty at Kuangshan Village is the tallest blast furnace that remains from ancient China. Previous studies have assumed that the furnace had a closed mouth. In this paper, a three-dimensional (3D) model of the blast furnace is constructed using 3D laser scanning technology, and accurate profile data are obtained using software. It is shown that the furnace throat is smaller than had been previously thought and that the furnace mouth is of the open type. This new furnace profile constitutes a discovery in the history of iron-smelting technology.

  4. Magnification Bias in Gravitational Arc Statistics

    Energy Technology Data Exchange (ETDEWEB)

    Caminha, G. B. [Rio de Janeiro, CBPF; Estrada, J. [Fermilab; Makler, M. [Rio de Janeiro, CBPF

    2013-08-29

    The statistics of gravitational arcs in galaxy clusters is a powerful probe of cluster structure and may provide complementary cosmological constraints. Despite recent progresses, discrepancies still remain among modelling and observations of arc abundance, specially regarding the redshift distribution of strong lensing clusters. Besides, fast "semi-analytic" methods still have to incorporate the success obtained with simulations. In this paper we discuss the contribution of the magnification in gravitational arc statistics. Although lensing conserves surface brightness, the magnification increases the signal-to-noise ratio of the arcs, enhancing their detectability. We present an approach to include this and other observational effects in semi-analytic calculations for arc statistics. The cross section for arc formation ({\\sigma}) is computed through a semi-analytic method based on the ratio of the eigenvalues of the magnification tensor. Using this approach we obtained the scaling of {\\sigma} with respect to the magnification, and other parameters, allowing for a fast computation of the cross section. We apply this method to evaluate the expected number of arcs per cluster using an elliptical Navarro--Frenk--White matter distribution. Our results show that the magnification has a strong effect on the arc abundance, enhancing the fraction of arcs, moving the peak of the arc fraction to higher redshifts, and softening its decrease at high redshifts. We argue that the effect of magnification should be included in arc statistics modelling and that it could help to reconcile arcs statistics predictions with the observational data.

  5. Making Conductive Polymers By Arc Tracking

    Science.gov (United States)

    Daech, Alfred F.

    1992-01-01

    Experimental technique for fabrication of electrically conductive polymeric filaments based on arc tracking, in which electrical arc creates conductive carbon track in material that initially was insulator. Electrically conductive polymeric structures made by arc tracking aligned along wire on which formed. Alignment particularly suited to high conductivity and desirable in materials intended for testing as candidate superconductors.

  6. Thermal analysis of an arc heater electrode with a rotating arc foot

    Science.gov (United States)

    Milos, Frank S.; Shepard, Charles E.

    1993-01-01

    A smoothly rotating arc foot and an arc foot that jumps between multiple sticking points were analyzed using analytic formulations and numerical solution procedures. For each case the temperature distribution for a copper electrode was obtained for the plausible range of operating conditions. It is shown that the smoothly rotating arc foot is an extremely safe mode of operation, whereas the jumping arc foot produces excessively high electrode surface temperatures which are not greatly alleviated by increasing the average rotational frequency of the arc foot. It is suggested to eliminate arc-foot rotation and rely on the distribution of fixed electrodes with stationary arc attachment to avoid electrode failure at high current.

  7. Carbothermal reduction process of silica formed from shirasu volcanic ash using solar furnace

    OpenAIRE

    Hatakeyama Keisuke; Sato Keigo; Nishioka Kensuke

    2016-01-01

    Metallurgical grade silicon was formed using Shirasu volcanic ash as starting material with solar furnace. The solar furnace was composed of two parts: Fresnel lens and reacting furnace. The reacting furnace was composed of a cylindrical vacuum chamber and quartz glass plate functioning to guide the concentrated sunlight into the furnace, and was placed at the focal point of the Fresnel lens. The sample was made from a mixture of silica formed from Shirasu volcanic ash and carbon, and placed ...

  8. Assessing energy efficiency of electric car bottom furnaces intended for thermal energization of minerals

    Science.gov (United States)

    Nizhegorodov, A. I.

    2017-01-01

    The paper deals with a new concept of electric furnaces for roasting and thermal energization of vermiculite and other minerals with vibrational transportation of a single-layer mass under constant thermal field. The paper presents performance calculation and comparative assessment of energy data for furnaces of different modifications: flame and electric furnaces with three units, furnaces with six units and ones with series-parallel connection of units, and furnaces of new concept.

  9. Hopewell Furnace NHS Small Scale Features (Linear Features)

    Data.gov (United States)

    National Park Service, Department of the Interior — This shapefile represents the linear small scale features found at Hopewell Furnace National Historic Site based on the Cultural Landscape Report completed in...

  10. Alloying and Casting Furnace for Shape Memory Alloys Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The concept in the proposed project is to create a melting, alloying and casting furnace for the processing titanium based SMA using cold crucible techniques. The...

  11. DEVELOPMENT OF A FURNACE TO FABRICATE SILICON SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    Sérgio Boscato Garcia

    2012-06-01

    Full Text Available Solar cell world market had an exponential growth in the last decade and nowadays it continues in expansion. To produce solar cells, dopants need to be introduced into the crystalline silicon wafer in order to form the pn junction. This process is carried out in diffusion furnaces. The aim of this paper is to present the development of a compact diffusion furnace to process up to 156 mm × 156 mm silicon wafers and to operate at temperature up to 1100°C. The furnace is automated and it is constituted by a heating system with three zones and systems to introduce the wafers inside the furnace as well as to control of gas flows. This equipment is the first one developed in Brazil to promote impurity diffusions in order to produce silicon solar cells and it was manufactured jointly with a Brazilian company.

  12. Prospects for the construction of solar furnaces for industry

    Science.gov (United States)

    La Blanchetais, Ch. H.

    The various techniques and prototype installations employed to absorb and concentrate solar energy for use in applications requiring 100-4000 C temperatures are explored. Mention is made of the Pericles heliostat field and the THEK distributed parabolic concentrator installations, and attention is focused on viable concepts useful for industrial purposes. The Odeillo solar furnace provided design guidelines and requirements for industrial usage. It was found that the reliability of the furnace depends on the annual insolation, that the solar furnaces must be designed to meet specific thermal goals, that simplification and optimization are needed for the orientation and focusing mechanisms, and that solar furnaces are ideally suited for developing nations which experience high levels of insolation. A stepped paraboloid is described for improving the efficiency of a heliostat system, while still employing plane parallel mirrors.

  13. Refractory Gunning Material for Inner Lining Maintenance of Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    Yu Lingyan; Peng Xigao

    2010-01-01

    @@ 1 Scope This standard specifies the term and definition,classification, technical requirements, test methods,quality appraisal procedures, packing, marking, transportation, storage, and quality certificate of refractory gunning material for inner lining maintenance of blast furnace .

  14. MINERGY CORPORATION GLASS FURNACE TECHNOLOGY EVALUATION: INNOVATION TECHNOLOGY EVALUATION REPORT

    Science.gov (United States)

    This report presents performance and economic data for a U.S. Environmental Protection Agency (EPA) Superfund Innovative Technology Evaluation (SITE) Program demonstration of the Minergy Corporation (Minergy) Glass Furnace Technology (GFT). The demonstration evaluated the techno...

  15. Optimization of the melting process of electrical furnaces in drenas

    Directory of Open Access Journals (Sweden)

    A. Haxhiaj

    2012-10-01

    Full Text Available The weight, composition and loads are the main parameters of the melting process in electrical furnace. The charge is roasted in rotary furnace. Roasting of charge which consists of Drenas and Albanians ore is done at about 950°C. Also, article has the experimental analyses that modify some parameters of the production which are the reduction of quantity of limestone and the increase of quantity of quartz in the charge. The paper analysis the possibility of mixing the ore from Kosova with lateritic ore from Albania with the aim of reducing the acidity of weight which is loaded in the electrical furnace. The composition of the furnace must satisfy the ratio 1:10 of ore from Kosova and Albania.

  16. Moving behavior of pellets in a pellet shaft furnace

    Institute of Scientific and Technical Information of China (English)

    梁儒全; 赫冀成

    2008-01-01

    The downward moving behavior of pellets in a 8 m2 pellet shaft furnace with an internal vertical air channel and a drying bed was studied by means of a visualized model(1-15) and a top model(1-1).The visualized model experiment shows that the downward movement of pellets can be regarded as plug flow approximately inside the furnace except for the lower region of cooling zone due to the influence of the drained hopper.The top model experiment reveals that the pellet sizes increase along the moving direction because of the percolation phenomenon,which results in a decrease of the resistance coefficient and an increase of the gas flow rate from the furnace wall toward the furnace center.

  17. Removal of phosphate from aqueous solution with blast furnace slag.

    Science.gov (United States)

    Oguz, Ensar

    2004-10-18

    Blast furnace slag was used to remove phosphate from aqueous solutions. The influence of pH, temperature, agitation rate, and blast furnace slag dosage on phosphate removal was investigated by conducting a series of batch adsorption experiments. In addition, the yield and mechanisms of phosphate removal were explained on the basis of the results of X-ray spectroscopy, measurements of zeta potential of particles, specific surface area, and images of scanning electron microscopy (SEM) of the particles before and after adsorption. The specific surface area of the blast furnace slag was 0.4m(2)g(-1). The removal of phosphate predominantly has taken place by a precipitation mechanism and weak physical interactions between the surface of adsorbent and the metallic salts of phosphate. In this study, phosphate removal in excess of 99% was obtained, and it was concluded that blast furnace slag is an efficient adsorbent for the removal of phosphate from solution.

  18. Radial furnace shows promise for growing straight boron carbide whiskers

    Science.gov (United States)

    Feingold, E.

    1967-01-01

    Radial furnace, with a long graphite vaporization tube, maintains a uniform thermal gradient, favoring the growth of straight boron carbide whiskers. This concept seems to offer potential for both the quality and yield of whiskers.

  19. CMOS Thermal Ox and Diffusion Furnace: Tystar Tytan 2000

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Names: CMOS Wet Ox, CMOS Dry Ox, Boron Doping (P-type), Phos. Doping (N-Type)This four-stack furnace bank is used for the thermal growth of silicon...

  20. Lightweight high temperature test furnace. 21st century technology

    Energy Technology Data Exchange (ETDEWEB)

    De Groot, F.C.

    2004-02-01

    A new high-temperature lightweight furnace design offers potential energy savings, thus reducing emissions and costs, and improves product quality. The Gasunie Research 12 m3 test furnace results are: 36% less heat needed to heat up the furnace; first tests show that 18% of flue gas heat loss is saved through pulse/pause firing; reduced carbon dioxide and gaseous hydrogen fluorides (HF) emissions; improved temperature homogeneity in product batch enables higher throughput; new dust-free combination of Refractory Ceramic Fibres (RCFs) have been tested successfully up to 1250C; new high-temperature vitreous wool (RCFs) with high solubility in body fluids and hence no hazard classification has been successfully tested; furnace control system developed and tested with good results, based on a standard industrial PLC, within stringent gas safety requirements.

  1. High Quality Silica Bricks for Glass Melting Furnace

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Chai Junlan

    2008-01-01

    @@ 1 Scope This standard specifies the classification, technical requirements, test method, inspection rules,marking,packing,transportation,storage and quality certification of high quality silica bricks for glass melting furnace.

  2. A simple arc column model that accounts for the relationship between voltage, current and electrode gap during VAR

    Energy Technology Data Exchange (ETDEWEB)

    Williamson, R.L. [Sandia National Labs., Albuquerque, NM (United States). Liquid Metal Processing Lab.

    1997-02-01

    Mean arc voltage is a process parameter commonly used in vacuum arc remelting (VAR) control schemes. The response of this parameter to changes in melting current (I) and electrode gap (g{sub e}) at constant pressure may be accurately described by an equation of the form V = V{sub 0} + c{sub 1}g{sub e}I + c{sub 2}g{sub e}{sup 2} + c{sub 3}I{sup 2}, where c{sub 1}, c{sub 2} and c{sub 3} are constants, and where the non-linear terms generally constitute a relatively small correction. If the non-linear terms are ignored, the equation has the form of Ohm`s law with a constant offset (V{sub 0}), c{sub 1}g{sub e} playing the role of resistance. This implies that the arc column may be treated approximately as a simple resistor during constant current VAR, the resistance changing linearly with g{sub e}. The VAR furnace arc is known to originate from multiple cathode spot clusters situated randomly on the electrode tip surface. Each cluster marks a point of exist for conduction electrons leaving the cathode surface and entering the electrode gap. Because the spot clusters re highly localized on the cathode surface, each gives rise to an arc column that may be considered to operate independently of other local arc columns. This approximation is used to develop a model that accounts for the observed arc voltage dependence on electrode gap at constant current. Local arc column resistivity is estimated from elementary plasma physics and used to test the model for consistency by using it to predict local column heavy particle density. Furthermore, it is shown that the local arc column resistance increases as particle density increases. This is used to account for the common observation that the arc stiffens with increasing current, i.e. the arc voltage becomes more sensitive to changes in electrode gap as the melting current is increased. This explains why arc voltage is an accurate electrode gap indicator for high current VAR processes but not low current VAR processes.

  3. Tectonomagmatism in continental arcs: evidence from the Sark arc complex

    Science.gov (United States)

    Gibbons, Wes; Moreno, Teresa

    2002-07-01

    The island of Sark (Channel Islands, UK) exposes syntectonic plutons and country rock gneisses within a Precambrian (Cadomian) continental arc. This Sark arc complex records sequential pulses of magmatism over a period of 7 Ma (ca. 616-609 Ma). The earliest intrusion (ca. 616 Ma) was a composite sill that shows an ultramafic base overlain by a magma-mingled net vein complex subsequently deformed at near-solidus temperatures into the amphibolitic and tonalitic Tintageu banded gneisses. The deformation was synchronous with D 2 deformation of the paragneissic envelope, with both intrusion and country rock showing flat, top-to-the-south LS fabrics. Later plutonism injected three homogeneous quartz diorite-granodiorite sheets: the Creux-Moulin pluton (150-250 m; ca. 614 Ma), the Little Sark pluton (>700 m; 611 Ma), and the Northern pluton (>500 m; 609 Ma). Similar but thinner sheets in the south (Derrible-Hogsback-Dixcart) and west (Port es Saies-Brecqhou) are interpreted as offshoots from the Creux-Moulin pluton and Little Sark pluton, respectively. All these plutons show the same LS fabric seen in the older gneisses, with rare magmatic fabrics and common solid state fabrics recording syntectonic crystallisation and cooling. The cooling rate increased rapidly with decreasing crystallisation age: >9 Ma for the oldest intrusion to cool to lower amphibolite conditions, 7-8 Ma for the Creux Moulin pluton, 5-6 Ma for the Little Sark pluton, and 10 -14 s -1) that focussed extensional deformation into the Sark area. The increased rates of extension allowed ingress of the subsequent quartz diorite-granodiorite sheets, although strain rate slowly declined as the whole complex cooled during exhumation. The regional architecture of syntectonic Cadomian arc complexes includes flat-lying "Sark-type" and steep "Guernsey-type" domains produced synchronously in shear zone networks induced by oblique subduction: a pattern seen in other continental arcs such as that running from Alaska

  4. Development Of A Magnetic Directional-Solidification Furnace

    Science.gov (United States)

    Aldrich, Bill R.; Lehoczky, Sandor L.

    1996-01-01

    Report describes development of directional-solidification furnace in which axial magnetic field is imposed by surrounding ring permanent magnets and/or electromagnets and pole pieces. Furnace provides controlled axial temperature gradients in multiple zones, through which ampoule containing sample of material to be solidified is translated at controlled speed by low-vibration, lead-screw, stepping-motor-driven mechanism. Intended for use in low-gravity (spaceflight) experiments on melt growth of high-purity semiconductor crystals.

  5. Residential Two-Stage Gas Furnaces - Do They Save Energy?

    Energy Technology Data Exchange (ETDEWEB)

    Lekov, Alex; Franco, Victor; Lutz, James

    2006-05-12

    Residential two-stage gas furnaces account for almost a quarter of the total number of models listed in the March 2005 GAMA directory of equipment certified for sale in the United States. Two-stage furnaces are expanding their presence in the market mostly because they meet consumer expectations for improved comfort. Currently, the U.S. Department of Energy (DOE) test procedure serves as the method for reporting furnace total fuel and electricity consumption under laboratory conditions. In 2006, American Society of Heating Refrigeration and Air-conditioning Engineers (ASHRAE) proposed an update to its test procedure which corrects some of the discrepancies found in the DOE test procedure and provides an improved methodology for calculating the energy consumption of two-stage furnaces. The objectives of this paper are to explore the differences in the methods for calculating two-stage residential gas furnace energy consumption in the DOE test procedure and in the 2006 ASHRAE test procedure and to compare test results to research results from field tests. Overall, the DOE test procedure shows a reduction in the total site energy consumption of about 3 percent for two-stage compared to single-stage furnaces at the same efficiency level. In contrast, the 2006 ASHRAE test procedure shows almost no difference in the total site energy consumption. The 2006 ASHRAE test procedure appears to provide a better methodology for calculating the energy consumption of two-stage furnaces. The results indicate that, although two-stage technology by itself does not save site energy, the combination of two-stage furnaces with BPM motors provides electricity savings, which are confirmed by field studies.

  6. CHARACTERIZATION AND ANALISYS OF A FURNACE TO FABRICATE SOLAR CELLS

    OpenAIRE

    Sérgio Boscato Garcia; Adriano Moehlecke; Izete Zanesco

    2013-01-01

    The solar cell industry has presented high growth rates and dealt with a large portfolio of suppliers for specific equipments like diffusion furnaces needed to produce the pn junction in the fabrication of silicon devices. The aim of this paper is to present the thermal analysis and the characterization of diffusions carried out in the first diffusion furnace developed and fabricated in Brazil. Longitudinal and radial temperature profiles were measured and analyzed. Results of the...

  7. Investigation of radiative heat transfer in fixed bed biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    T. Klason; X.S. Bai; M. Bahador; T.K. Nilsson; B. Sunden [Lund Institute of Technology, Lund (Sweden). Division of Fluid Mechanics

    2008-08-15

    This paper presents an investigation of the radiative heat transfer process in two fixed bed furnaces firing biomass fuels and the performance of several widely used models for calculation of radiative heat transfer in the free-room of fixed bed furnaces. The effective mean grey gas absorption coefficients are calculated using an optimised version of the exponential wide band model (EWBM) based on an optical mean beam length. Fly-ash and char particles are taken into account using Mie scattering. In the investigated updraft small-scale fixed bed furnace radiative transfer carries heat from the bed to the free-room, whereas in the cross-current bed large-scale industry furnace, radiative transfer brings heat from the hot zones in the free-room to the drying zone of the bed. Not all the investigated models can predict these heat transfer trends, and the sensitivity of results to model parameters is fairly different in the two furnaces. In the small-scale furnace, the gas absorption coefficient predicted by using different optical lengths has great impact on the predicted temperature field. In the large-scale furnaces, the predicted temperature field is less sensitive to the optical length. In both furnaces, with the same radiative properties, the low-computational-cost P1 model predicts a temperature field in the free-room similar to that by the more time consuming SLW model. In general, the radiative heat transfer rates to the fuel bed are not very sensitive to the radiative properties, but they are sensitive to the different radiative heat transfer models. For a realistic prediction of the radiative heat transfer rate to the fuel bed or to the walls, more computationally demanding models such as the FGG or SLW models should be used. 37 refs., 7 figs., 2 tabs.

  8. Development of heat-transfer circuits in the blast furnace

    Science.gov (United States)

    Spirin, N. A.; Yaroshenko, Yu G.; Lavrov, V. V.

    2016-09-01

    The development of heat-transfer circuits in the blast furnace as the technologies of blast-furnace smelting are improved are considered. It is shown that there are two zones of intense heat-transfer, and in modern conditions, when different kinds of iron ore are smelted, the use of combined blast with high parameters is a prerequisite for the stability of blastfurnace smelting operation and the smelting efficiency.

  9. Slagging and Fouling Characteristics of HRSG for Ferrosilicon Electric Furnaces

    OpenAIRE

    2015-01-01

    The slagging and fouling characteristics of the heat recovery steam generator (HRSG) for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF), X-ray powder diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the ash samples. The results show that low melting point salt Na 2 SO 4 and composit...

  10. MUZO flight experience with the programmable multizone furnace

    Science.gov (United States)

    Lockowandt, Christian; Loth, Kenneth

    1993-01-01

    The Multi-Zone (MUZO) furnace has been developed for growing germanium (Ge) crystals under microgravity in a Get Away Special (GAS) payload. The MUZO furnace was launched with STS-47 Endeavour in September 1992. The payload worked as planned during the flight and a Ge sample was successfully processed. The experiment has given valuable scientific information. The design and functionality of the payload together with flight experience is reported.

  11. Modelling the CANMET and Marchwood furnaces using the PCOC code

    Energy Technology Data Exchange (ETDEWEB)

    Stopford, P.J.; Marriott, N. (AEA Decommissioning and Radioactive Waste, Harwell (UK). Theoretical Studies Dept.)

    1990-01-01

    Pulverised coal combustion models are validated by detailed comparison with in-flame measurements of velocity, temperatures and species concentrations on two axisymmetric tunnel furnaces. Nitric oxide formation by the thermal and fuel nitrogen mechanisms is also calculated and compared with experiment. The sensitivity of the predictions to the various aspects of the model and the potential for modelling full-scale, power-generating furnaces are discussed. 18 refs., 13 figs.

  12. Monitoring Method for Blast Furnace Wall With Copper Staves

    Institute of Scientific and Technical Information of China (English)

    CHENG Su-sen; QIAN Liang; ZHAO Hong-bo

    2007-01-01

    A monitoring method that has been designed for the first time for blast furnace wall with copper staves manufactured in China was introduced. Combining the method of "inverse problem" and the concept "non-inverse problem", the monitoring program for blast furnace wall with copper staves has been realized, which can be used to calculate online the accretion thickness and temperature of hot surface of copper staves after obtaining the values of thermocouples of copper staves. The accretion state obtained in the actual investigation has proved that the result of the program is correct. The monitoring program shows that the accretion would easily fluctuate when the accretion layer is extremely thick or thin, thereby the stable and smooth operation of the blast furnace is hindered. By maintaining appropriate accretion thickness, both long campaigns and high productivity of the blast furnace can be achieved; furthermore, it can also optimize the operation of blast furnace and maximize its production. Approximately 30-50 mm in thickness of accretion layer is maintained on the wall of Shougang blast furnace 2, which can meet the requirement for obtaining both long campaign and high productivity.

  13. Mathematical model and software for control of commissioning blast furnace

    Science.gov (United States)

    Spirin, N. A.; Onorin, O. P.; Shchipanov, K. A.; Lavrov, V. V.

    2016-09-01

    Blowing-in is a starting period of blast furnace operation after construction or major repair. The current approximation methods of blowing-in burden analysis are based on blowing-in practice of previously commissioned blast furnaces. This area is theoretically underexplored; there are no common scientifically based methods for selection of the burden composition and blast parameters. The purpose of this paper is development and scientific substantiation of the methods for selection of the burden composition and blast parameters in the blast furnace during the blowing-in period. Research methods are based on physical regularities of main processes running in the blast furnace, system analysis, and application of modern principles for development and construction of mathematical models, algorithms and software designed for automated control of complex production processes in metallurgy. As consequence of the research made by the authors the following results have been achieved: 1. A set of mathematical models for analysis of burden arrangement throughout the height of the blast furnace and for selection of optimal blast and gas dynamic parameters has been developed. 2. General principles for selection of the blowing-in burden composition and blast and gas dynamic parameters have been set up. 3. The software for the engineering and process staff of the blast furnace has been developed and introduced in the industry.

  14. Laboratory Evaluation of Residential Furnace BlowerPerformance

    Energy Technology Data Exchange (ETDEWEB)

    Walker, Iain S.; Lutz, Jim D.

    2005-09-01

    A testing program was undertaken at Lawrence Berkeley National Laboratory and an electric utility (Pacific Gas and Electric Co.) to compare the performance of furnace blowers. This laboratory testing program was undertaken to support potential changes to California Building Standards regarding in-field furnace blower energy use. This technical support includes identifying suitable performance metrics and target performance levels for use in standards. Five different combinations of blowers and residential furnaces were tested for air moving performance. Three different types of blower and motor combinations were tested in two different furnace cabinets. The blowers were standard forward--curved impellors and a prototype impeller with reverse-inclined blades. The motors were two 6-pole permanent split capacitor (PSC) single-phase induction motors, a brushless permanent magnet (BPM) motor and a prototype BPM designed for use with a prototype reverse-inclined impellor. The laboratory testing operated each blower and furnace combination over a range of air flows and pressure differences to determine air flow performance, power consumption and efficiency. Additional tests varied the clearance between the blower housing and the furnace cabinet, and the routing of air flow into the blower cabinet.

  15. A pressurized drop-tube furnace for coal reactivity studies

    Science.gov (United States)

    Ouyang, Shan; Yeasmin, Hasina; Mathews, Joseph

    1998-08-01

    The design and characterization of a pressurized drop-tube furnace for investigation of coal devolatilization, gasification, and combustion are presented. The furnace is designed for high-temperature, isothermal operation in a developing laminar flow regime. It can be operated at pressures up to 1600 kPa, and temperatures up to 1673 K, with variable reaction time, particle feeding rate, and with inert and various oxidizing atmospheres. Particle residence times can be varied between ˜0.02 and ˜10 s depending upon operating conditions and positions of injection and sampling probes. Observations ports are available for sample collections and for optical investigation of the reactions or temperature measurements. Characterization of gas temperature in the furnace shows that, although the gas temperature profile in the furnace is affected by the water-cooled injection probe, the furnace is able to achieve isothermal operation in a developing laminar flow regime. Results from a series of brown coal devolatilization tests demonstrated the suitability of the furnace for experiments in coal research.

  16. A Contribution to Arc Length Discussion

    Directory of Open Access Journals (Sweden)

    Stephan Egerland

    2015-09-01

    Full Text Available Abstract An investigation was raising the question: "What does 'arc length' mean?" Actually, it is considered expressing a kind of natural relationship between arc voltage and arc column shape. Statements such as "The higher the voltage the longer the arc" or "The arc voltage proves approximately proportional to the arc length", are frequently noticed in this conjunction. However, the author suggests that there is no general possibility of describing 'arc length' over the whole welding process range. Instances are represented in this paper, showing both theoretical attempts of definition and practical observations. This paper intends to contribute to a serious discussion of something trivial, indeed very well-known or used among welding experts, but actually yet hardly understood, at least as when it comes to closer examination

  17. Boundary Identification for a Blast Furnace

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, the authors discuss an inverse boundary problem for the axisymmetric steady-state heat equation, which arises in monitoring the boundary corrosion for the blast-furnace. Measure temperature at some locations are used to identify the shape of the corrosion boundary.The numerical inversion is complicated and consuming since the wear-line varies during the process and the boundary in the heat problem is not fixed. The authors suggest a method that the unknown boundary can be represented by a given curve plus a small perturbation, then the equation can be solved with fixed boundary, and a lot of computing time will be saved.A method is given to solve the inverse problem by minimizing the sum of the squared residual at the measuring locations, in which the direct problems are solved by axisymmetric fundamental solution method.The numerical results are in good agreement with test model data as well as industrial data, even in severe corrosion case.

  18. Gas Flow Distribution in Pelletizing Shaft Furnace

    Institute of Scientific and Technical Information of China (English)

    CAI Jiu-ju; DONG Hui; WANG Guo-sheng; YANG Jun

    2006-01-01

    Through thermal test, cold state experiment, analysis and simulation of thermal process, the gas flow distribution in pelletizing shaft furnace (PSF) was discussed. The results show that there are five flowing trends; among them, the downward roasting gas and the upward cooling gas are the most unsteady, which influence flow distribution greatly. Among the operating parameters, the ratio of inflow is a key factor affecting the flow distribution. The roasting and cooling gases will entirely flow into the roasting zone and internal vertical air channels (IVAC), respectively, if the ratio of inflow is critical. From such a critical operating condition increasing roasting gas flow or decreasing cooling gas flow, the roasting gas starts flowing downwards so as to enter the inside of IVAC; the greater the ratio of inflow, the larger the downward flowrate. Among constructional parameters, the width of roasting zone b1, width of IVAC b2 and width of cooling zone b3, and the height of roasting zone h1, height of soaking zone h2 and height of cooling zone h3 are the main factors affecting flow distribution. In case the ratio of b2/b1, or h3/h2, or h1/h2 is increased, the upward cooling gas tends to decrease while the downward roasting gas tends to increase with a gradual decrease in the ratio of inflow.

  19. FINDING WAYS OF RECYCLING DUST OF ARC STEEL FURNACES AT THE BELARUSIAN METALLURGIC PLANT. PART 3. EXPERIMENTS ON BRIQUETTING OF DUST OFARC STEEL FURNACES

    Directory of Open Access Journals (Sweden)

    A. I. Rozhkov

    2015-01-01

    Full Text Available The article gives an overview of the global experience of recycling dust by briquetting. The advantages and disadvantages of recycling dust with its preliminary briquetting are described. Information about experiments on briquetting of dust generated in different organizations of the Belarusian metallurgy plant with various binders is given. Economic calculations were performed on the basis of technical data obtained during the manufacture of prototypes of briquettes. The results of the calculations showedinexpediency of recycling dust briquetting method because of the low iron content in the dust, high cost of binder and a relatively small rate of ecological tax.

  20. Zircon Recycling in Arc Intrusions

    Science.gov (United States)

    Miller, J.; Barth, A.; Matzel, J.; Wooden, J.; Burgess, S.

    2008-12-01

    Recycling of zircon has been well established in arc intrusions and arc volcanoes, but a better understanding of where and how zircons are recycled can help illuminate how arc magma systems are constructed. To that end, we are conducting age, trace element (including Ti-in-zircon temperatures; TzrnTi) and isotopic studies of zircons from the Late Cretaceous (95-85 Ma) Tuolumne Intrusive Suite (TIS) in the Sierra Nevada Batholith (CA). Within the TIS zircons inherited from ancient basement sources and/or distinctly older host rocks are uncommon, but recycled zircon antecrysts from earlier periods of TIS-related magmatism are common and conspicuous in the inner and two most voluminous units of the TIS, the Half Dome and Cathedral Peak Granodiorites. All TIS units have low bulk Zr ([Zr]825°C), [Zr] in the TIS is a factor of 2 to 3 lower than saturation values. Low [Zr] in TIS rocks might be attributed to a very limited supply of zircon in the source, by disequilibrium melting and rapid melt extraction [1], by melting reactions involving formation of other phases that can incorporate appreciable Zr [2], or by removal of zircon at an earlier stage of magma evolution. Based on a preliminary compilation of literature data, low [Zr] is common to Late Cretaceous N.A. Cordilleran granodioritic/tonalitic intrusions (typically Tzrnsat [3]. A corollary is that slightly older zircon antecrysts that are common in the inner units of the TIS could be considered inherited if they are derived from remelting of slightly older intrusions. Remelting at such low temperatures in the arc would require a source of external water. Refs: [1] Sawyer, J.Pet 32:701-738; [2] Fraser et al, Geology 25:607-610; [3] Harrison et al, Geology 35:635- 638

  1. Mechanisms of phosphate removal from aqueous solution by blast furnace slag and steel furnace slag

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    We report the adsorption of phosphate and discuss the mechanisms of phosphate removal from aqueous solution by burst furnace slag (BFS) and steel furnace slag (SFS). The results show that the adsorption of phosphate on the slag was rapid and the majority of adsorption was completed in 5~10 min. The adsorption capacity of phosphate by the slag was reduced dramatically by acid treatment. The relative contribution of adsorption to the total removal of phosphate was 26%~28%. Phosphate adsorption on BFS and SFS follows the Freundlich isotherm, with the related constants ofk 6.372 and 1/n 1.739 for BFS, and ofk 1.705 and 1/n 1.718 for SFS. The pH and Ca2+ concentration were decreased with the addition of phosphate, suggesting the formation of calcium phosphate precipitation. At pH 2.93 and 6.93, phosphate was desorbed by about 36%~43% and 9%~11%, respectively.These results indicate that the P adsorption on the slag is not completely reversible and that the bond between the slag particles and adsorbed phosphate is strong. The X-ray diffraction (XRD) patterns of BFS and SFS before and after phosphate adsorption verify SFS is related to the formation of phosphate calcium precipitation and the adsorption on hydroxylated oxides. The results show that BFS and SFS removed phosphate nearly 100%, indicating they are promising adsorbents for the phosphate removal in wastewater treatment and pollution control.

  2. Pulverized coal burnout in blast furnace simulated by a drop tube furnace

    Energy Technology Data Exchange (ETDEWEB)

    Du, Shan-Wen [Steel and Aluminum Research and Development Department, China Steel Corporation, Kaohsiung 812 (China); Chen, Wei-Hsin [Department of Greenergy, National University of Tainan, Tainan 700 (China); Lucas, John A. [School of Engineering of the University of Newcastle, Callaghan, NSW 2308 (Australia)

    2010-02-15

    Reactions of pulverized coal injection (PCI) in a blast furnace were simulated using a drop tube furnace (DTF) to investigate the burnout behavior of a number of coals and coal blends. For the coals with the fuel ratio ranging from 1.36 to 6.22, the experimental results indicated that the burnout increased with decreasing the fuel ratio, except for certain coals departing from the general trend. One of the coals with the fuel ratio of 6.22 has shown its merit in combustion, implying that the blending ratio of the coal in PCI operation can be raised for a higher coke replacement ratio. The experiments also suggested that increasing blast temperature was an efficient countermeasure for promoting the combustibility of the injected coals. Higher fuel burnout could be achieved when the particle size of coal was reduced from 60-100 to 100-200 mesh. However, once the size of the tested coals was in the range of 200 and 325 mesh, the burnout could not be improved further, resulting from the agglomeration of fine particles. Considering coal blend reactions, the blending ratio of coals in PCI may be adjusted by the individual coal burnout rather than by the fuel ratio. (author)

  3. H_2O and CO_2 in magmas from the Mariana arc and back arc systems

    OpenAIRE

    Newman, Sally; Stolper, Edward; STERN, Robert

    2000-01-01

    We examined the H2O and CO2 contents of glasses from lavas and xenoliths from the Mariana arc system, an intraoceanic convergent margin in the western Pacific, which contains an active volcanic arc, an actively spreading back arc basin, and active behind-the-arc cross-chain volcanoes. Samples include (1) glass rims from Mariana arc, Mariana trough, and cross-chain submarine lavas; (2) glass inclusions in arc and trough phenocrysts; and (3) glass inclusions from a gabbro + anorthosite xenolith...

  4. Arc Root Attachment on the Anode Surface of Arc Plasma Torch Observed with a Novel Method

    Institute of Scientific and Technical Information of China (English)

    PAN Wen-Xia; LI Teng; MENG Xian; CHEN Xi; WU Cheng-Kang

    2005-01-01

    @@ The arc-root attachment on the anode surface of a dc non-transferred arc plasma torch has been successfullyobserved using a novel approach. A specially designed copper mirror with a boron nitride film coated on itssurface central-region is employed to avoid the effect of intensive light emitted from the arc column upon theobservation of weakly luminous arc root. It is found that the arc-root attachment is diffusive on the anode surfaceof the argon plasma torch, while constricted arc roots often occur when hydrogen or nitrogen is added into argonas the plasma-forming gas.

  5. Reappraisal of the Arc-Arc Collision in Taiwan

    Directory of Open Access Journals (Sweden)

    Tetsuzo Seno and Yoshiaki Kawanishi

    2009-01-01

    Full Text Available Al though it is evident that Taiwan has been formed by the collision of the west-facing Luzon arc with the Eurasian continental mar gin, _ main a lot of enigmas in this collision. The major ones are: (1 a trans form fault presently connecting the Manila and Ryukyu Trenches in the Philippine Sea _ Eurasia relative motion direction is missing, and in stead, the Ryukyu Trench ex tends near off shore E. Tai wan, (2 the western edge of the intermediate-depth seismicity associated with We pro pose a new model of the collision in Tai wan to re solve these enigmas, assuming that the southern Ryukyu forearc was mi grating to the south west with respect to Eurasia for the past several m.y. and the Luzon arc has been colliding with this actively migrating Ryukyu forearc. The northern most Luzon arc is divided into two parts by the NNW line directing along the Philippine Sea - Ryukyu forearc motion from its initial intersection point with the Ryukyu Trench; the part west of this line has been obducted on the Ryukyu forearc-Eurasian mar gin, producing the collision orogen in Taiwan, and the part east of it has been subducted beneath the Ryukyu forearc. This evolutionary scenario resolves enigmas (1 and (2 kinematically. This model also predicts that the South China Sea slab has to be torn by the west ward component of the motion of the subducting Philippine Sea slab to Eurasia. This would have brought large lateral compression in the shallow portion of the Philippine Sea slab at its western border, which might lead to buck ling of the slab causing the ob served undulated gravity anomaly.

  6. Portland cement-blast furnace slag blends in oilwell cementing applications

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D.T.; DiLullo, G.; Hibbeler, J. [and others

    1995-12-31

    Recent investigations of blast furnace slag cementing technologies. have been expanded to include Portland cement/blast furnace slag blends. Mixtures of Portland cement and blast furnace slag, while having a long history of use in the construction industry, have not been used extensively in oilwell cementing applications. Test results indicate that blending blast furnace slag with Portland cement produces a high quality well cementing material. Presented are the design guidelines and laboratory test data relative to mixtures of blast furnace slag and Portland cements. Case histories delineating the use of blast furnace slag - Portland cement blends infield applications are also included.

  7. PSI's 1kW imaging furnace-A tool for high-temperature chemical reactivity studies

    Energy Technology Data Exchange (ETDEWEB)

    Guesdon, C.; Alxneit, I.; Tschudi, H.R.; Wuillemin, D.; Brunner, Y.; Winkel, L.; Sturzenegger, M. [Laboratory for High-Temperature Solar Technology, Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Petrasch, J. [Professorship for Renewable Energy Carriers, ETHZ Zentrum, 8092 Zurich (Switzerland)

    2006-10-15

    A new experiment has been installed to conduct studies at temperatures as high as 2500K on chemical reactions that involve solids or melts and the release of condensable gases. The sample is radiatively heated by a 1kW xenon short arc lamp placed in the upper focus of a vertically oriented ellipsoid of revolution. The optimal optical configuration has been determined by a Monte-Carlo Ray tracing method. Several methods to machine the reflector have been evaluated by experimentally determining the optical quality of the surface of plane test pieces. In the imaging furnace the sample is placed on a water-cooled support and heated by the concentrated radiation. This arrangement allows for fast heating and impedes the reaction of the sample with crucible material. A remotely controlled hammer allows for freezing the high-temperature composition of the sample by a fast quench. Thus, the sample can be later analyzed by conventional methods such as XRD or TEM. To allow for measurements under defined atmospheres and to protect the ellipsoidal reflector from liberated condensable products, the entire sample stage is enclosed by a hemispherical glass dome. The dome itself is protected from condensable compounds by a laminar flow of inert gas. Experiments with an incense cone at the place of the sample to visualize the gas flow showed that a steady layer of inert gas protects the dome from smoke, if the inert gas flow is properly adjusted. Measured peak flux densities clearly exceed 500Wcm{sup -2} required to access temperatures of at least 2500K. Decomposition experiments on copper sulfides confirmed the operation of the furnace. In the near future flash assisted multi-wavelength pyrometry (FAMP) will be implemented to measure sample temperatures online. Though the imaging furnace was developed to study the decomposition of metal sulfides it is obviously suited to conduct high-temperature studies on most materials relevant for high-temperature solar technology. (author)

  8. Altitude effects on combustion in residential furnaces with fan assist

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, S.; Fleck, B.A.; Ackerman, M.Y.; Dale, J.D.; Wilson, D.J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

    2002-07-01

    Five residential furnaces were tested to determine if altitude has an effect on the performance of modern furnaces equipped with fan assisted flue venting systems. The tests were conducted at 3 altitudes, 50 m, 685 m and 2050 m above sea level at sites in Vancouver, Edmonton, and Fortress Mountain, Alberta. Current furnace derating practices require that furnaces at high altitude have small fuel openings or decreased fuel supply manifold pressures. However, it is possible that modern furnaces with fan driven combustion venting do not have to be derated to the same extent. Propane and natural gas were the fuel sources for the tests. It was confirmed that since most residential systems are designed to operate at 100 per cent excess air, the current derating standard practice is overly conservative. The effects of altitude on carbon monoxide and carbon dioxide levels were also examined, along with burner and igniter operating characteristics, heat exchanger operating temperatures, and blocked-vent shutoff combustion performance. 1 tab., 3 figs.

  9. Programming ArcGIS with Python cookbook

    CERN Document Server

    Pimpler, Eric

    2015-01-01

    Programming ArcGIS with Python Cookbook, Second Edition, is written for GIS professionals who wish to revolutionize their ArcGIS workflow with Python. Whether you are new to ArcGIS or a seasoned professional, you almost certainly spend time each day performing various geoprocessing tasks. This book will teach you how to use the Python programming language to automate these geoprocessing tasks and make you a more efficient and effective GIS professional.

  10. Miniaturized cathodic arc plasma source

    Science.gov (United States)

    Anders, Andre; MacGill, Robert A.

    2003-04-15

    A cathodic arc plasma source has an anode formed of a plurality of spaced baffles which extend beyond the active cathode surface of the cathode. With the open baffle structure of the anode, most macroparticles pass through the gaps between the baffles and reflect off the baffles out of the plasma stream that enters a filter. Thus the anode not only has an electrical function but serves as a prefilter. The cathode has a small diameter, e.g. a rod of about 1/4 inch (6.25 mm) diameter. Thus the plasma source output is well localized, even with cathode spot movement which is limited in area, so that it effectively couples into a miniaturized filter. With a small area cathode, the material eroded from the cathode needs to be replaced to maintain plasma production. Therefore, the source includes a cathode advancement or feed mechanism coupled to cathode rod. The cathode also requires a cooling mechanism. The movable cathode rod is housed in a cooled metal shield or tube which serves as both a current conductor, thus reducing ohmic heat produced in the cathode, and as the heat sink for heat generated at or near the cathode. Cooling of the cathode housing tube is done by contact with coolant at a place remote from the active cathode surface. The source is operated in pulsed mode at relatively high currents, about 1 kA. The high arc current can also be used to operate the magnetic filter. A cathodic arc plasma deposition system using this source can be used for the deposition of ultrathin amorphous hard carbon (a-C) films for the magnetic storage industry.

  11. Boxicity of Circular Arc Graphs

    OpenAIRE

    Bhowmick, Diptendu; Chandran, L. Sunil

    2008-01-01

    A $k$-dimensional box is the cartesian product $R_1 \\times R_2 \\times ... \\times R_k$ where each $R_i$ is a closed interval on the real line. The {\\it boxicity} of a graph $G$, denoted as $box(G)$, is the minimum integer $k$ such that $G$ can be represented as the intersection graph of a collection of $k$-dimensional boxes: that is two vertices are adjacent if and only if their corresponding boxes intersect. A circular arc graph is a graph that can be represented as the intersection graph of ...

  12. Electrode Evaporation Effects on Air Arc Behavior

    Institute of Scientific and Technical Information of China (English)

    LI Xingwen; CHEN Degui; LI Rui; WU Yi; NIU Chunping

    2008-01-01

    A numerical study of the effects of copper and silver vapours on the air arc behavior is performed. The commercial software FLUENT is adapted and modified to develop a two-dimensional magneto-hydrodynamic (MHD) models of arc with the thermodynamic properties and transport coefficients, net emission coefficient for the radiation model of 99% ai-1% Cu, 99% air-1% Ag, and pure air, respectively. The simulation result demonstrates that vaporization of the electrode material may cool the arc center region and reduce the arc velocity. The effects of Ag vapour are stronger compared to those of Cu vapour.

  13. The Team Orienteering Arc Routing Problem

    OpenAIRE

    Archetti, Claudia; Speranza, M. Grazia; Corberan, Angel; Sanchís Llopis, José María; Plana, Isaac

    2014-01-01

    The team orienteering arc routing problem (TOARP) is the extension to the arc routing setting of the team orienteering problem. In the TOARP, in addition to a possible set of regular customers that have to be serviced, another set of potential customers is available. Each customer is associated with an arc of a directed graph. Each potential customer has a profit that is collected when it is serviced, that is, when the associated arc is traversed. A fleet of vehicles with a given maximum trav...

  14. Class `E` protective headwear: electric arc exposure

    Energy Technology Data Exchange (ETDEWEB)

    Jones, E.

    1997-04-01

    A series of tests were conducted using electric arcs under laboratory conditions to determine what, if any, damages can be inflicted upon class `E` hard hats. Ten hard hats were subjected to different levels of arc exposure to see if the hat would ignite, melt, drip, stick to the head, etc. It was noted that there is no standard on hard hat exposure to an electric arc. It was recommended that the CSA committee revise the protective headwear standard to include a requirement for flame/arc resistance, including specification of pass/fail criteria. 1 tab., 3 figs.

  15. Effects of Silicon and Furnace Conditions on Hot Shortness

    Science.gov (United States)

    Sampson, Erica E.

    Residual Cu in scrap based steel manufactured in the Electric Arc Furnace (EAF) leads to a surface cracking phenomenon known as surface hot shortness. Si is known to provide a potential reduction in hot shortness; however, the mechanisms involved are not fully understood for low Si quantities. This study aims to determine a window of Si contents with a given Ni content needed to counteract the negative effects of Sn and Cu to reduce hot shortness and to determine the mechanism. Thermogravimetric Analysis, SEM-EDS, XRD, and TEM were used to study the hot shortness behavior of a Fe alloy containing 0.2% Cu, 0.05% Ni, 0.01% Sn and with varying Si-content (0.02%, 0.1%, 0.15%, and 0.2% Si). It was found that fayalite formation at the metal/oxide interface resulted in a reduction of oxidation and subsequent Cu-rich liquid formation for all Si contents examined. Under isothermal air oxidation experiments, the range of Si contents between 0.1-0.2 wt% Si exhibited a mechanism that was a combination of fayalite formation impeding oxidation as well as occlusion of the Cu-rich liquid due to internal oxidation. This range was acceptable to alleviate hot shortness under these conditions. Following continuous casting, steel undergoes a cooling process known as secondary cooling where water is sprayed on the surface to promote cooling followed by a radiant cooling stage where the steel is cooled in air to room temperature. The secondary cooling regime leads to oxidation of the alloy in an air + water vapor atmosphere. Experiments were completed to determine the effect of the non-isothermal secondary cooling cycle, the effect of water vapor during secondary cooling, and the effect of the radiant cooling regime down to room temperature. In the case of secondary cooling atmospheres, the non-isothermal cooling cycle resulted in a slight increase in liquid quantity and grain boundary penetration as compared to the isothermal heating cycles due to the higher temperatures experienced in

  16. CHARACTERIZATION AND ANALISYS OF A FURNACE TO FABRICATE SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    Sérgio Boscato Garcia

    2013-06-01

    Full Text Available The solar cell industry has presented high growth rates and dealt with a large portfolio of suppliers for specific equipments like diffusion furnaces needed to produce the pn junction in the fabrication of silicon devices. The aim of this paper is to present the thermal analysis and the characterization of diffusions carried out in the first diffusion furnace developed and fabricated in Brazil. Longitudinal and radial temperature profiles were measured and analyzed. Results of the characterization defined a processing zone of 200 mm with temperature variation lower than 6°C for the temperatures up to 965°C. In the processing zone, 40 silicon wafers can be processed. Diffusion processes were performed in monocrystalline silicon wafers and n+ regions doped with phosphorus presented standard deviation of sheet resistance slightly higher than that obtained in imported commercial furnaces. Wafer contamination was not observed during diffusion processes and the minority carrier lifetime was improved.

  17. Evaporation of graphite using a solar furnace: production of fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Laplaze, D.; Bernier, P.; Journet, C.; Vie, V. [Groupe de Dynamique des Phases Condensees, Univ. de Montpellier II (France); Flamant, G.; Philippot, E.; Lebrun, M. [Inst. de Sciences et de Genie des Materiaux et Procedes, Centre du Four Solaire Felix Trombe, 66 - Font-Romeu (France)

    1997-12-31

    We have previously shown that the high intensity of solar radiation, obtained with the Odeillo (France) solar furnace facilities, can be used to vaporize graphite in inert gas atmosphere to produce fullerenes. After a short survey of the possible mechanisms of formation of these molecules, we report some experimental results in agreement with the proposed model and discuss the possibilities of increasing the fullerenes yield which currently reaches 20%. One of these possibilities consists in the use of the 1000 kW solar furnace of the Institute and we report results of simulation for this furnace which show that temperature of the sublimation zone can be greater than the needed 3300 K necessary to have convenient efficiency. (orig.)

  18. Simulation of chondrule formation in the DLR solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Sauerborn, M.; Neumann, A. [German Aerospace Center (DLR), High Flux Solar Furnace, Solar Energy Technology, Cologne (Germany); Klerner, S. [Inst. of Mineralogy and Geochemistry, Univ. of Cologne (Germany); Seboldt, W.; Hanowski, N. [German Aerospace Center (DLR), Inst. of Space Sensor Technology and Planetary Exploration, Cologne (Germany)

    2001-07-01

    A new vacuum chamber was installed in the DLR solar furnace in Cologne and tested for the first time in an experiment with small solid samples being melted and solidified subsequently. The goal of the actual project is to simulate the formation of so-called 'chondrules' - constituents of meteorites - by heating appropriate mineral samples with the concentrated beam of a solar furnace. The experiment has to be carried out under vacuum or oxygen free conditions. The project is a co-operation between the High Flux Solar Furnace of the DLR in Cologne (a department of the Solar Technology Division), the Mission Architecture and Advanced Technologies Section (a department of the Institute of Space Sensor Technology and Planetary Exploration of the DLR) and the Institute of Mineralogy and Geochemistry of the University of Cologne. (orig.)

  19. Solar furnace satellite for large diameter crystal growth in space

    Science.gov (United States)

    Overfelt, Tony; Wells, Mark; Blake, John

    1993-02-01

    Investigators worldwide are preparing experiments to test the influence of low gravity found in space on the growth of many crystalline materials. However, power limitations prevent existing space crystal growth furnaces from being able to process samples any larger than about 2 cm, and in addition, the background microgravity levels found on the Space Shuttle are not low enough to significantly benefit samples much larger than 2 cm. This paper describes a novel concept of a free-flying platform utilizing well-established solar furnace technology to enable materials processing in space experiments on large-diameter crystals. The conceptual design of this Solar Furnace Satellite is described along with its operational scenario and the anticipated g levels.

  20. IMPROVED FURNACE EFFICIENCY THROUGH THE USE OF REFRACTORY MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Rodrigues-Schroer, Angela [Minteq International, Inc.; Colavito, [Minteq International, Inc.; Smith, Jeffrey D [ORNL

    2011-01-01

    This paper describes efforts performed at Oak Ridge National Laboratory (ORNL), in collaboration with industrial refractory manufacturers, refractory users, and academic institutions, to improve energy efficiency of U.S. industry through increased furnace efficiency brought about by the employment of novel refractory systems and techniques. Work in furnace applications related to aluminum, gasification, and lime are discussed. The energy savings strategies discussed are achieved through reduction of chemical reactions, elimination of mechanical degradation caused by the service environment, reduction of temperature limitations of materials, and elimination of costly installation and repair needs. Key results of several case studies resulting from a US Department of Energy (DOE) funded research program are discussed with emphasis on applicability of these results to high temperature furnace applications.

  1. Thermal valorisation of automobile shredder residue: injection in blast furnace.

    Science.gov (United States)

    Mirabile, Daphne; Pistelli, Maria Ilaria; Marchesini, Marina; Falciani, Roberta; Chiappelli, Lisa

    2002-01-01

    Wastes with residual heating value, according to the trend of the world legislation, could be thermally reused. The present study is conducted to verify the possibility of thermal valorisation of a waste, denominated fluff, by injection in blast furnace. The fluff, arising from the automobile shredder operations, is a waste characterised by a high organic matrix and is potentially dangerous due to the heavy metals, oils filter and halogenated plastics content. The first step of the work is the chemical, physical and toxicological characterisation of this material. Then the fluff injection in a blast furnace tuyere is theoretically analysed with a mathematical model. Finally, experimental trials are conducted in a pilot plant, simulating the most important part of the blast furnace: the raceway, in order to analyse process and industrial aspects. In view of an industrial application a first economical evaluation is carried out on the basis of model and experimental results.

  2. Investigation on the Potentials of Cupola Furnace Slag in Concrete

    Directory of Open Access Journals (Sweden)

    Stephen Adeyemi Alabi

    2013-12-01

    Full Text Available The compressive strength of the concrete designed using blast cupola furnace slag and granulated cupola slag as a coarse aggregate and partial replacement for cement was investigated. A series of experimental studies were conducted involve concrete production in two stages. The first stage comprised of normal aggregate concrete (NAC produced with normal aggregates and 100% ordinary Portland cement (OPC. Meanwhile, the second stage involved production of concrete comprising of cupola furnace slag an aggregates with 100% ordinary Portland cement (OPC and subsequently with 2%, 4%, 6%, 8% and 10% cementitious replacement with granulated cupola furnace slag that had been grounded and milled to less than 75 µm diameter. The outcomes of compressive strength test conducted on the slag aggregate concrete (SAC with and without granulated slag cementitious replacement were satisfactory compared to normal aggregate concretes (NAC.

  3. A Composite Model Predictive Control Strategy for Furnaces

    Institute of Scientific and Technical Information of China (English)

    Hao Zang; Hongguang Li; Jingwen Huang; Jia Wang

    2014-01-01

    Tube furnaces are essential and primary energy intensive facilities in petrochemical plants. Operational optimi-zation of furnaces could not only help to improve product quality but also benefit to reduce energy consumption and exhaust emission. Inspired by this idea, this paper presents a composite model predictive control (CMPC) strategy, which, taking advantage of distributed model predictive control architectures, combines tracking nonlinear model predictive control and economic nonlinear model predictive control metrics to keep process running smoothly and optimize operational conditions. The control ers connected with two kinds of communi-cation networks are easy to organize and maintain, and stable to process interferences. A fast solution algorithm combining interior point solvers and Newton's method is accommodated to the CMPC realization, with reason-able CPU computing time and suitable online applications. Simulation for industrial case demonstrates that the proposed approach can ensure stable operations of furnaces, improve heat efficiency, and reduce the emission effectively.

  4. Evaluation on chemical stability of lead blast furnace (LBF) and imperial smelting furnace (ISF) slags.

    Science.gov (United States)

    Yin, Nang-Htay; Sivry, Yann; Guyot, François; Lens, Piet N L; van Hullebusch, Eric D

    2016-09-15

    The leaching behavior of Pb and Zn from lead blast furnace (LBF) and imperial smelting furnace (ISF) slags sampled in the North of France was studied as a function of pHs and under two atmospheres (open air and nitrogen). The leaching of major elements from the slags was monitored as a function of pH (4, 5.5, 7, 8.5 and 10) under both atmospheres for different slag-water interaction times (1 day and 9 days). The leaching results were coupled with a geochemical model; Visual MINTEQ version 3.0, and a detailed morphological and mineralogical analysis was performed on the leached slags by scanning and transmission electron microscopy (SEM and TEM). Significant amounts of Ca, Fe and Zn were released under acidic conditions (pH 4) with a decrease towards the neutral to alkaline conditions (pH 7 and 10) for both LBF and ISF slags. On the other hand, Fe leachability was limited at neutral to alkaline pH for both slags. The concentrations of all elements increased gradually after 216 h compared to initial 24 h of leaching period. The presence of oxygen under open-air atmosphere not only enhanced oxidative weathering but also encouraged formation of secondary oxide and carbonate phases. Formation of carbonates and clay minerals was suggested by Visual MINTEQ which was further confirmed by SEM & TEM. The hydration and partial dissolution of hardystonite, as well as the destabilization of amorphous glassy matrix mainly contributed to the release of major elements, whereas the spinel related oxides were resistant against pH changes and atmospheres within the time frame concerned for both LBF and ISF slags. The total amount of Pb leached out at pH 7 under both atmospheres suggested that both LBF and ISF slags are prone to weathering even at neutral environmental conditions.

  5. Feedback Linearization Based Arc Length Control for Gas Metal Arc Welding

    DEFF Research Database (Denmark)

    Thomsen, Jesper Sandberg

    2005-01-01

    In this paper a feedback linearization based arc length controller for gas metal arc welding (GMAW) is described. A nonlinear model describing the dynamic arc length is transformed into a system where nonlinearities can be cancelled by a nonlinear state feedback control part, and thus, leaving only...

  6. Loss on Ignition Furnace Acceptance and Operability Test Procedure

    Energy Technology Data Exchange (ETDEWEB)

    JOHNSON, D.C.

    2000-06-01

    The purpose of this Acceptance Test Procedure and Operability Test Procedure (ATP/OTP)is to verify the operability of newly installed LOI equipment, including a model 1608FL CM{trademark} Furnace, a dessicator, and balance. The operability of the furnace will be verified. The arrangement of the equipment placed in Glovebox 157-3/4 to perform Loss on Ignition (LOI) testing on samples supplied from the Thermal Stabilization line will be verified. In addition to verifying proper operation of the furnace, this ATP/OTP will also verify the air flow through the filters, verify a damper setting to establish and maintain the required differential pressure between the glovebox and the room pressure, and test the integrity of the newly installed HEPA filter. In order to provide objective evidence of proper performance of the furnace, the furnace must heat 15 crucibles, mounted on a crucible rack, to 1000 C, according to a program entered into the furnace controller located outside the glovebox. The glovebox differential pressure will be set to provide the 0.5 to 2.0 inches of water (gauge) negative pressure inside the glovebox with an airflow of 100 to 125 cubic feet per minute (cfm) through the inlet filter. The glovebox inlet Glfilter will he flow tested to ensure the integrity of the filter connections and the efficiency of the filter medium. The newly installed windows and glovebox extension, as well as all disturbed joints, will be sonically tested via ultra probe to verify no leaks are present. The procedure for DOS testing of the filter is found in Appendix A.

  7. The influence of sunshape on the DLR solar furnace beam

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.; Witzke, A. [Deutsches Zentrum fuer Luft und Raumfahrt e.V., Koeln (Germany). Solare Energietechnik

    1999-08-01

    The circumsolar ratio CSR is often used as a simple description of the relevant solar energy feature of the solar brightness distribution, known as sunshape. The variation of the CSR can affect the performance of solar concentrators. DLR has conducted sunshape studies since the beginning of the design phase of the DLR Solar Furnace in 1992. In addition, in 1996 a mobile sunshape measurement system was developed with which many CSR measurements have been performed since then. These investigations are still going on for statistical purposes in parallel with the operation of the solar furnace. This work shows new and unique data of simultaneous sunshape records and solar furnace beam diameter measurements. For narrow sun conditions with a CSR < 1% the solar furnace beam has a diameter of less than 13 cm. Atmospheric conditions with a higher forward scattering can cause the CSR to exceed 10%, sometimes even above 40%. In the latter case the focal beam measurement showed a beam diameter of more than 16 cm. The increase of the focal diameter turned out to be linear with respect to CSR variation. The measured sunshapes were introduced into the ray-tracing model OPTEC, built for solar furnace and heliostat field simulation. The model results for the DLR Solar Furnace flux maps were compared to the measurements. The model does not show the same linear trend for increasing CSR, but the deviation is not too pronounced. The influence of CSR on the focal spot size leads to a nonlinear decrease with direct normal irradiance of the power collected by a predesigned receiver aperture. Depending on the aperture size, an additional decrease of the order of 10-15% will be encountered under higher CSR conditions. (author)

  8. Furnace Blower Electricity: National and Regional Savings Potential

    Energy Technology Data Exchange (ETDEWEB)

    Florida Solar Energy Center; Franco, Victor; Franco, Victor; Lutz, Jim; Lekov, Alex; Gu, Lixing

    2008-05-16

    Currently, total electricity consumption of furnaces is unregulated, tested at laboratory conditions using the DOE test procedure, and is reported in the GAMA directory as varying from 76 kWh/year to 1,953 kWh/year. Furnace blowers account for about 80percent of the total furnace electricity consumption and are primarily used to distribute warm air throughout the home during furnace operation as well as distribute cold air during air conditioning operation. Yet the furnace test procedure does not provide a means to calculate the electricity consumption during cooling operation or standby, which account for a large fraction of the total electricity consumption. Furthermore, blower electricity consumption is strongly affected by static pressure. Field data shows that static pressure in the house distribution ducts varies widely and that the static pressure used in the test procedure as well as the calculated fan power is not representative of actual field installations. Therefore, accurate determination of the blower electricity consumption is important to address electricity consumption of furnaces and air conditioners. This paper compares the potential regional and national energy savings of two-stage brushless permanent magnet (BPM) blower motors (the blower design option with the most potential savings that is currently available in the market) to single-stage permanent split capacitor (PSC) blower motors (the most common blower design option). Computer models were used to generate the heating and cooling loads for typical homes in 16 different climates which represent houses throughout the United States. The results show that the potential savings of using BPM motors vary by region and house characteristics, and are very strongly tied to improving house distribution ducts. Savings decrease dramatically with increased duct pressure. Cold climate locations will see savings even in the high static pressure duct situations, while warm climate locations will see less

  9. ATLAS DDM integration in ARC

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Cameron, David; Ellert, Mattias;

    2008-01-01

    The Nordic Data Grid Facility (NDGF) consists of Grid resources running ARC middleware in Denmark, Finland, Norway and Sweden. These resources serve many virtual organisations and contribute a large fraction of total worldwide resources for the ATLAS experiment, whose data is distributed and mana......The Nordic Data Grid Facility (NDGF) consists of Grid resources running ARC middleware in Denmark, Finland, Norway and Sweden. These resources serve many virtual organisations and contribute a large fraction of total worldwide resources for the ATLAS experiment, whose data is distributed...... and managed by the DQ2 software. Managing ATLAS data within NDGF and between NDGF and other Grids used by ATLAS (the Enabling Grids for E-sciencE Grid and the Open Science Grid) presents a unique challenge for several reasons. Firstly, the entry point for data, the Tier 1 centre, is physically distributed...... outside the worker node environment. Also, the service used for cataloging the location of data files is different from otherGrids but must still be useable by DQ2 and ATLAS users to locate data within NDGF. This paper presents in detail how we solve these issues to allow seamless access worldwide to data...

  10. Double mirror polyheliostat solar furnace of 1000 kW thermal power

    Energy Technology Data Exchange (ETDEWEB)

    Riskiev, T.T.; Suleimanov, S.K.H. (Uzbek Academy of Sciences, Scientific Association ' Physics Sun' , Tashkent (USSR))

    1991-12-01

    The optical-energetic scheme, construction and performance of a double mirror polyheliostat solar furnace of 1000 kW thermal power are outlined and first results of material synthesis in this solar furnace are reported. (orig.).

  11. Prediction of heater power distribution in radiative cylindrical furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Ravichandran, M.; Dilber, I.; Torok, D.

    1999-07-01

    In the design of long radiative cylindrical furnaces, it is important to control the temperature variation along the furnace walls and consequently the temperature distribution in the processed material by selectively adjusting the power input to heater rods located circumferentially around the furnace walls. The heaters are grouped in zones located at different axial locations. By adjusting the power to each zone a specified temperature distribution along the furnace can be attained. The radiative interchange between different axial zones of the furnace affects the temperature distribution; this interchange is also impacted by the shadowing caused by the presence of the load, i.e. the processed material. A desired temperature distribution can only be achieved by selectively changing the power input to the heaters. For an a priori assessment of the commercial viability of using process friendly temperature distributions, it is necessary to determine: (a) the maximum power demand from each zone; (b) if active cooling is inevitable and (c) the bounds on temperature distribution that can be achieved without active cooling. It is therefore extremely useful to be able to predict the input power distribution for achieving desired furnace temperature profiles. For a given power input, the temperature distribution inside the furnace could be obtained by using a general purpose Computational Fluid Dynamics (CFD) software, such as FIDAP. A new methodology is developed within the framework of FIDAP software to eliminate the manual trial and error method. The method is based on obtaining the sensitivity of the temperature at the desired locations of the furnace as a function of the power input to the heating elements. Using these sensitivity coefficients, an iterative scheme is designed to adjust the boundary conditions (power to the heating elements in this case) based on the discrepancy of the solution temperatures from the desired temperature distribution. For each of these

  12. Simulation study on radiative imaging of combustion flame in furnace

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Radiative imaging of combustion flame in furnace of power plant plays an increasingly important role in combustion diagnosis. This paper presents a new method for calculating the radiative imaging of three-dimensional (3D) combustion flame based on Monte Carlo method and optical lens imaging. Numerical simulation case was used in this study. Radiative images were calculated and images obtained can not only present the energy distribution on the charge-coupled device (CCD) camera target plane but also reflect the energy distribution condition in the simulation furnace. Finally the relationships between volume elements and energy shares were also discussed.

  13. Numerical Simulation of Fluid Flow in Blast Furnace Hearth

    Institute of Scientific and Technical Information of China (English)

    ZHAO Min-ge; SUN Tian-liang; CHENG Su-sen; GAO Zheng-kai

    2005-01-01

    The liquid flow in blast furnace hearth can result in the erosion of hearth. To prolong the campaign life of blast furnace, the effects of coke bed structure, coke porosity and deepness of taphole on liquid flow in hearth were studied by κ-ε model under different conditions. The results show that with the decrease of coke porosity, the peripheral flow is enhanced. Moreover, the existence of narrow coke free zone and the deepness reduction of taphole can increase the flowability on the bottom of hearth.

  14. Regulation of the Heating Furnace in Tube Rolling Mill

    Directory of Open Access Journals (Sweden)

    Kostúr, K.

    2006-01-01

    Full Text Available The rolling of tube requires homogeneous heating along the tube. In steel work the difference along tube was sometimes 80 °C. The reasons for bad homogeneousness of heating were analyzed by a simulation model of heating furnace. Then the proposal was made for a new control system and also the proposal for reconstruction of furnace. In this contribution also a description of some ways for improvement of heating was made. The main contribution is the proposal of an adaptive system

  15. The effect of blast furnace coke quality on the possibility of its use

    OpenAIRE

    A. Konstanciak

    2013-01-01

    In the paper behavior of the blast-furnace coke in the high temperature was presented. Comparative analysis of the chemical composition of the blast-furnace coke and the heat treatment of it were done. Coefficients M10 and M40 with the thermo-abrasiveness for chosen cokes were compared. The influence of ash content of the coke on the blast-furnace bed permeability was defined. Usefulness of the coke to blast-furnace process was also defined.

  16. Numerical Study of the Reduction Process in an Oxygen Blast Furnace

    Science.gov (United States)

    Zhang, Zongliang; Meng, Jiale; Guo, Lei; Guo, Zhancheng

    2016-02-01

    Based on computational fluid dynamics, chemical reaction kinetics, principles of transfer in metallurgy, and other principles, a multi-fluid model for a traditional blast furnace was established. The furnace conditions were simulated with this multi-fluid mathematical model, and the model was verified with the comparison of calculation and measurement. Then a multi-fluid model for an oxygen blast furnace in the gasifier-full oxygen blast furnace process was established based on this traditional blast furnace model. With the established multi-fluid model for an oxygen blast furnace, the basic characteristics of iron ore reduction process in the oxygen blast furnace were summarized, including the changing process of the iron ore reduction degree and the compositions of the burden, etc. The study found that compared to the traditional blast furnace, the magnetite reserve zone in the furnace shaft under oxygen blast furnace condition was significantly reduced, which is conducive to the efficient operation of blast furnace. In order to optimize the oxygen blast furnace design and operating parameters, the iron ore reduction process in the oxygen blast furnace was researched under different shaft tuyere positions, different recycling gas temperatures, and different allocation ratios of recycling gas between the hearth tuyere and the shaft tuyere. The results indicate that these three factors all have a substantial impact on the ore reduction process in the oxygen blast furnace. Moderate shaft tuyere position, high recycling gas temperature, and high recycling gas allocation ratio between hearth and shaft could significantly promote the reduction of iron ore, reduce the scope of the magnetite reserve zone, and improve the performance of oxygen blast furnace. Based on the above findings, the recommendations for improvement of the oxygen blast furnace design and operation were proposed.

  17. Optical diagnostics of a gliding arc

    DEFF Research Database (Denmark)

    Sun, Z.W.; Zhu, J.J.; Li, Z.S.;

    2013-01-01

    Dynamic processes in a gliding arc plasma generated between two diverging electrodes in ambient air driven by 31.25 kHz AC voltage were investigated using spatially and temporally resolved optical techniques. The life cycles of the gliding arc were tracked in fast movies using a high-speed camera...

  18. Modeling and Simulation of Low Voltage Arcs

    NARCIS (Netherlands)

    Ghezzi, L.; Balestrero, A.

    2010-01-01

    Modeling and Simulation of Low Voltage Arcs is an attempt to improve the physical understanding, mathematical modeling and numerical simulation of the electric arcs that are found during current interruptions in low voltage circuit breakers. An empirical description is gained by refined electrical m

  19. Measurement of an Electric Arc Spectra

    OpenAIRE

    Šimek, D.

    2015-01-01

    Article is focused on electric arc spectroscopy diagnostics related to electric low voltage apparatuses. The first attempts of spectroscopy measurements are dealt with. An example of radiation spectra of the electric arc burning between copper electrodes is presented. The problems connected with the measurements are discussed.

  20. Implementing RapidArc into clinical routine

    DEFF Research Database (Denmark)

    Van Esch, Ann; Huyskens, Dominique P; Behrens, Claus F;

    2011-01-01

    With the increased commercial availability of intensity modulated arc therapy (IMAT) comes the need for comprehensive QA programs, covering the different aspects of this newly available technology. This manuscript proposes such a program for the RapidArc (RA) (Varian Medical Systems, Palo Alto...

  1. The structure and singularities of arc complexes

    DEFF Research Database (Denmark)

    Penner, Robert

    A classical combinatorial fact is that the simplicial complex consisting of disjointly embedded chords in a convex planar polygon is a sphere. For any surface F with non-empty boundary, there is an analogous complex Arc(F) consisting of suitable equivalence classes of arcs in F connecting its bou...

  2. Characterization of Micro-arc Oxidized Titanium

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The observation of the sparkling discharges during the micro-arc oxidation process in KOH aqueous electrolyte was achieved. The change of surface morphology was progressively observed and a plausible pore formation mechanism is proposed. Cell proliferation and ALP activity of micro-arc oxidized titanium was evaluated by human body derived osteoblasts and slightly better than those of blasted surface.

  3. The next-generation ARC middleware

    DEFF Research Database (Denmark)

    Appleton, O.; Cameron, D.; Cernak, J.

    2010-01-01

    The Advanced Resource Connector (ARC) is a light-weight, non-intrusive, simple yet powerful Grid middleware capable of connecting highly heterogeneous computing and storage resources. ARC aims at providing general purpose, flexible, collaborative computing environments suitable for a range of use...

  4. Radiation from Large Gas Volumes and Heat Exchange in Steam Boiler Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Makarov, A. N., E-mail: tgtu-kafedra-ese@mail.ru [Tver State Technical University (Russian Federation)

    2015-09-15

    Radiation from large cylindrical gas volumes is studied as a means of simulating the flare in steam boiler furnaces. Calculations of heat exchange in a furnace by the zonal method and by simulation of the flare with cylindrical gas volumes are described. The latter method is more accurate and yields more reliable information on heat transfer processes taking place in furnaces.

  5. 40 CFR 424.50 - Applicability; description of the other calcium carbide furnaces subcategory.

    Science.gov (United States)

    2010-07-01

    ... calcium carbide furnaces subcategory. 424.50 Section 424.50 Protection of Environment ENVIRONMENTAL... CATEGORY Other Calcium Carbide Furnaces Subcategory § 424.50 Applicability; description of the other calcium carbide furnaces subcategory. The provisions of this subpart are applicable to...

  6. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨飞; 马瑞光; 吴翊; 孙昊; 纽春萍; 荣命哲

    2012-01-01

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  7. Gliding arc triggered microwave plasma arc at atmospheric pressure for coal gasification application

    Science.gov (United States)

    Jain, Vishal; Visani, A.; Patil, C.; Patel, B. K.; Sharma, P. K.; John, P. I.; Nema, S. K.

    2014-08-01

    Plasma torch is device that efficiently converts electrical energy in to thermal energy for various high temperature applications. The conventional plasma torch comprises of consumable electrodes namely anode and cathode electrodes. The replacement of these electrodes is a complex process owing to its cooling and process shut down requirements. However, microwave plasma arc is electrode-less plasma arc system that is an alternative method to conventional arc technology for generating plasma arc. In this technique, microwave power is efficiently coupled to generate plasma arc by using the property of polar molecule to absorb microwave power. The absorption of microwave power is in form of losses due to intermolecular friction and high collisions between the molecules. This is an efficient method because all microwave power can be absorbed by plasma arc. The main feature of microwave plasma arc is its large uniform high temperature column which is not possible with conventional arc discharge methods. Such type of plasma discharge is very useful in applications where sufficient residence time for treat materials is required. Microwave arc does not require any consumable electrodes and hence, it can be operated continuously that makes it very useful for hazardous effluent treatment applications. Further, microwave cannot ionize neutral particles at atmospheric pressure and hence, a gliding arc is initiated between two thin electrodes in the cavity by applying very low power high voltage (3kV) AC source. In this report, the method for generating microwave arc of 1kW power using commercial microwave oven is elaborated.

  8. Arc burst pattern analysis fault detection system

    Science.gov (United States)

    Russell, B. Don (Inventor); Aucoin, B. Michael (Inventor); Benner, Carl L. (Inventor)

    1997-01-01

    A method and apparatus are provided for detecting an arcing fault on a power line carrying a load current. Parameters indicative of power flow and possible fault events on the line, such as voltage and load current, are monitored and analyzed for an arc burst pattern exhibited by arcing faults in a power system. These arcing faults are detected by identifying bursts of each half-cycle of the fundamental current. Bursts occurring at or near a voltage peak indicate arcing on that phase. Once a faulted phase line is identified, a comparison of the current and voltage reveals whether the fault is located in a downstream direction of power flow toward customers, or upstream toward a generation station. If the fault is located downstream, the line is de-energized, and if located upstream, the line may remain energized to prevent unnecessary power outages.

  9. INTERPOLATION WITH RESTRICTED ARC LENGTH

    Institute of Scientific and Technical Information of China (English)

    Petar Petrov

    2003-01-01

    For given data (ti,yi), I= 0,1,…,n,0 = t0 <t1 <…<tn = 1we study constrained interpolation problem of Favard type inf{‖f"‖∞|f∈W2∞[0,1],f(ti)=yi,i=0,…,n,l(f;[0,1])≤l0}, wherel(f";[0,1])=∫1 0 / 1+f'2(x)dx is the arc length off in [0,1]. We prove the existence of a solution f* of the above problem, that is a quadratic spline with a second derivative f"* , which coincides with one of the constants - ‖f"*‖∞,0,‖f"*‖∞ between every two consecutive knots. Thus, we extend a result ofKarlin concerning Favard problem, to the case of restricted length interpolation.

  10. Computer simulation to arc spraying

    Institute of Scientific and Technical Information of China (English)

    梁志芳; 李午申; 王迎娜

    2004-01-01

    The arc spraying process is divided into two stages: the first stage is atomization-spraying stream (ASS) and the second one is spraying deposition (SD). Then study status is described of both stages' physical model and corresponding controlling-equation. Based on the analysis of study status, the conclusion as follows is got. The heat and mass transfer models with two or three dimensions in ASS stage should be established to far deeply analyses the dynamical and thermal behavior of the overheat droplet. The statistics law of overheated droplets should be further studied by connecting simulation with experiments. More proper validation experiments should be designed for flattening simulation to modify the models in SD stage.

  11. ATLAS DDM integration in ARC

    DEFF Research Database (Denmark)

    Behrmann, Gerd; Cameron, David; Ellert, Mattias;

    The Nordic Data Grid Facility (NDGF) consists of Grid resources running ARC middleware in Scandinavia and other countries. These resources serve many virtual organisations and contribute a large fraction of total worldwide resources for the ATLAS experiment, whose data is distributed and managed...... by the DQ2 software. Managing ATLAS data within NDGF and between NDGF and other Grids used by ATLAS (the LHC Computing Grid and the Open Science Grid) presents a unique challenge for several reasons. Firstly, the entry point for data, the Tier 1 centre, is physically distributed among heterogeneous...... environment. Also, the service used for cataloging the location of data files is different from other Grids but must still be useable by DQ2 and ATLAS users to locate data within NDGF. This paper presents in detail how we solve these issues to allow seamless access worldwide to data within NDGF....

  12. High temperature corrosion behavior of arc-sprayed aluminum coatings on steel

    Institute of Scientific and Technical Information of China (English)

    SUN Jian-bo; WANG Yong; DONG Li-xian

    2004-01-01

    Aluminum coatings were sprayed on the substrate of steel Q235 by arc spraying. The test samples of Q235, Al coatings and Al coatings with seal coat were placed in box type electric resistance furnace at 400, 500,600, 650 ℃ when their oxidation behaviors were studied. And their oxidation kinetics curves were protracted. Microstructure, microhardness, bond strength and distribution of section elements were investigated by optical microscope(OM), Vickers microhardness instrument, electric tensile test machine and EPMA. Al coatings and Al coatings with seal coat can enhance the oxidation-resistance of substrate under 500 ℃. The latter has the best corrosion resistance. The coatings can't protect the substrate against oxidation above 600 ℃. After a long time corrosion there is enriched oxygen element at interface.

  13. Application of microcomputers for electric arc heating processes. Session 2. 2b N. 2. 2. 13

    Energy Technology Data Exchange (ETDEWEB)

    Gitarts, D.A.; Izakson-Demidov, Y.A.; Kalistratov, V.A.; Edemsky, V.M.

    1984-01-01

    Control systems employed with furnaces for steel production and for smelting of ores together with installations of electroslag and vacuum-arc remelting equipments are described. Details of mathematical models and control algorithms is given in addition to the schematic electrical circuits and lists of component parts of the control systems. The particular feature of the mathematical model is the application of the general state parameters and the static methods for their identification and adaptation. The variety of control system types employed in electroheat and having the possibility of using microcomputers, allows for expediency by using a single system approach for designing algorithm, a programme and the hardware to be used. Provision of the hardware to be employed for the real-time system, is based on a developed system of interruptions and use of a single library of hard and software modules, the latter having a general design of its layout for the different systems.

  14. Synthesis of carbon nanotubes by laser ablation in graphite substrate of industrial arc electrodes

    Science.gov (United States)

    Guerrero, A.; Puerta, J.; Gomez, F.; Blanco, F.

    2008-10-01

    In this work, an inexpensive and simple technique for the synthesis of carbon nanotubes (CNTs) by using graphite as the target for IR laser radiation is presented. This graphite material is obtained from the recycled graphite electrode core of an electric arc furnace. The experiment was carried out in a reaction chamber in an argon atmosphere at a low pressure. For laser ablation, a Lumonics TEA CO2 laser beam (7 J; 0.05-50 μs pulse length) was used in multimode operation. Products were collected on free mica sheets. The substrates were characterized by scanning electron microscopy (SEM) and the products were characterized (collected as powder) by transmission electron microscopy (TEM). They showed significant amounts of high-quality dense filaments (CNTs) that were morphologically not aligned.

  15. Evaluation of the graphite electrode arc melter for processing heterogeneous waste

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, William K.; Turner, Paul C.; Soelberg, N.R. (Idaho National Engineering Laboratory); Anderson, G.L. (Idaho National Engineering Laboratory)

    1996-01-01

    The U.S. Bureau of Mines (USBM) conducted a series of 4 demonstration melting tests in a 3-phase AC graphite electrode arc furnace at its Albany Research Center (ALRC) thermal treatment facility in Albany, Oregon (now part of the U.S. Department of Energy, DOE). The scope of these tests provides a unique opportunity to evaluate a single melting technology regarding its applicability to the treatment of several different heterogeneous mixed wastes. The current system can continuously process combustible-bearing wastes at feedrates to 682 kg/h (1,500 lb/h), continuously tap slag or glass, and intermittently tap metal products, and includes a close-coupled thermal oxidizer and air pollution control system (APCS). The 4 demonstration melting tests were conducted in cooperation with the American Society of Mechanical Engineers (ASME), the Idaho National Engineering Laboratory (INEL), and the Westinghouse Hanford Company (WHC).

  16. Temperature control of a solar furnace for material testing

    Science.gov (United States)

    Costa, B. Andrade; Lemos, J. M.; Rosa, L. G.

    2011-08-01

    A solar furnace is a thermodynamic device that concentrates sun radiation in order to achieve high-temperatures at a focus, where a sample of the material to be tested is located. This article address the problem of designing a control architecture for solar furnaces. It is motivated by the use of a solar furnace as an instrument in material science research to perform two types of experimental tests. In the first type, samples are tested in high-temperature stress cycles. In these experiments it is important to control the temperature profile. The second test type is characterised by imposing a solar radiation flux profile. On both experiment types there are strong nonlinear effects, a significant degree of parametric uncertainty and disturbances, such as solar radiation fluctuation due to clouds and to sun's apparent movement. Although the actuator (shutter) is much faster than the thermic system, it may destabilise the overall controlled system. The contribution of this article consists in the design of a control architecture for solar furnaces and the application of singular perturbation methods in order to derive conditions in the form of bounds for the speed of actuator dynamics so that the closed-loop system is stable.

  17. The investigation of melting process on the solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Suleimanov, S.Kh.; Bugakov, A.G. [Uubek Academy of Sciences, Materials Science Institute, Tashkent (Uzbekistan); Boehmer, M.; Fend, T. [DLR MD-ET, Cologne (Germany)

    1999-03-01

    The outcomes of a trial of new melting method on the solar furnace with horizontal optical axis by means of side fusion of rotatable ceramic sample with continuous restoration of the surface by charge is presented. The different development of the melting processes on the sample depending on the it's rotation speed is detected. (authors)

  18. Silicon solar cell monitors high temperature furnace operation

    Science.gov (United States)

    Zellner, G. J.

    1968-01-01

    Silicon solar cell, attached to each viewpoint, monitors that incandescent emission from the hot interior of a furnace without interfering with the test assembly or optical pyrometry during the test. This technique can provide continuous indication of hot spots or provide warning of excessive temperatures in cooler regions.

  19. Experimenting with concentrated sunlight using the DLR solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, A.; Groer, U. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt Linder Hoehe, Koeln (Germany)

    1996-10-01

    The high flux solar furnace that is operated by the Deutsche Forschungsanstalt fuer Luft- und Raumfahrt (DLR) at Cologne was inaugurated in June 1994 and we are now able to look back onto one year of successful operation. The solar furnace project was founded by the government of the State Northrhine Westfalia within the Study Group AG Solar. The optical design is a two-stage off-axis configuration which uses a flat 52 m{sup 2} heliostat and a concentrator composed of 147 spherical mirror facets. The heliostat redirects the solar light onto the concentrator which focuses the beam out of the optical axis of the system into the laboratory building. At high insolation levels (>800W/m{sup 2}) it is possible to collect a total power of 20 kW with peak flux densities of 4 MW/m{sup 2}. Sixteen different experiment campaigns were carried out during this first year of operation. The main research fields for these experiments were material science, component development and solar chemistry. The furnace also has its own research program leading to develop sophisticated measurement techniques like remote infrared temperature sensing and flux mapping. Another future goal to be realized within the next five years is the improvement of the performance of the furnace itself. 6 refs., 9 figs., 1 tab.

  20. Research on Microwave Heating-Direct Steelmaking in Electric Furnace

    Institute of Scientific and Technical Information of China (English)

    CHEN Jin; LIU Liu; ZENG Jia-qing; REN Rui-gang; LIU Jin-ying

    2005-01-01

    Self-fluxing iron ore concentrates containing coal have good microwave absorbability.With the voluminal heating property of microwave,the concentrates can be reduced uniformly and swiftly.The metallized semi-product can be directly charged into electric furnace for making clean steel.The total consumed energy of overall route is about 20.98 GJ.

  1. DEMONSTRATION BULLETIN: THE PLASMA CENTRIFUGAL FURNACE RETECH, INC.

    Science.gov (United States)

    The plasma centrifugal furnace is a thermal technology which uses the heat generated from a plasma torch to decontaminate metal and organic contaminated waste. This is accomplished by melting metal-bearing solids and, in the process, thermally destroying organic contaminants. The...

  2. Analysis of a furnace for heat generation using polydisperse biomass

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Edney Alves; Silva, Juarez de Sousa e; Silva, Jadir Nogueira da; Oliveira Filho, Delly [Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola; Donzeles, Sergio Mauricio Lopes [Empresa de Pesquisa Agropecuaria de Minas Gerais (EPAMIG), Vicosa, MG (Brazil)

    2008-07-01

    In many agro-industrial activities, the processing of raw material generates a substantial amount of fine materials. Examples include the production of soluble coffee, processing of rice, and wood processing, among others. In many regions, these by-products keep piling up on the courtyard of companies or become an environmental problem for land dumps. However, detailed tests of these byproducts indicate that they are excellent sources of energy. With this in mind, a furnace was developed to generate clean and hot air, using the alimentation system for pneumatic transport. Wood sawdust was used as fuel for analysis. The obtained results were considered satisfactory, proven by the small heat losses, primarily by the non-burned carbon monoxide (less than 0.2%) and the cooling of the furnace (less than 2.5%) whereas the losses by the exhaust gases were a little more than 23%. The thermal efficiency of the furnace was considered high when compared to others with an indirect heating system, obtaining an average value of 73%. The developed furnace, beyond being efficient, allows the use of the waste from the wood industry, which is important in the reduction of environmental impacts and minimizing production costs associated with the acquisition of conventional energy. (author)

  3. Analyses of laser and furnace treated sol-gel coatings

    NARCIS (Netherlands)

    De Hosson, JT; De Haas, M; Sudarshan, TS; Jeandin, M; Khor, KA

    1998-01-01

    Here we explore a new method that allows thin films to be made with almost any composition and degree of porosity by means of a combination of sol-gel and laser technology. Results are presented for furnace and laser treated TEOTI-(tetraethylorthotitanate as sol precursor) coated silicon samples. Fr

  4. Sliding mode controllers for a tempered glass furnace.

    Science.gov (United States)

    Almutairi, Naif B; Zribi, Mohamed

    2016-01-01

    This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system's parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results.

  5. The Iron Blast Furnace: A Study in Chemical Thermodynamics.

    Science.gov (United States)

    Treptow, Richard S.; Jean, Luckner

    1998-01-01

    Discusses the furnace from a chemical thermodynamics perspective. Examines the enthalpy, entropy, and free energy change for each reaction of importance. These properties are interpreted on the molecular level then used to deduce the conditions necessary for each reaction to occur in its intended direction. Chemical kinetics is also discussed.…

  6. APPLICATIONS ANALYSIS REPORT: BABCOCK AND WILCOX CYCLONE FURNACE

    Science.gov (United States)

    This document is an evaluation of the performance of the Babcock & Wilcox (B&W) Cyclone Furnace Vitrification Technology and its applicability as a treatment technique for soils contaminated with heavy metals, radionuclides, and organics. oth the technical and economic aspects of...

  7. Analysis of combustion efficiency in a pelletizing furnace

    Directory of Open Access Journals (Sweden)

    Rafael Simões Vieira de Moura

    Full Text Available Abstract The objective of this research is to assess how much the improvement in the combustion reaction efficiency can reduce fuel consumption, maintaining the same thermal energy rate provided by the reaction in a pelletizing furnace. The furnace for pelletizing iron ore is a complex thermal machine, in terms of energy balance. It contains recirculation fan gases and constant variations in the process, and the variation of a single process variable can influence numerous changes in operating conditions. This study demonstrated how the main variables related to combustion in the burning zone influence fuel consumption (natural gas from the furnace of the Usina de Pelotização de Fábrica (owned by VALE S/A, without changing process conditions that affect production quality. Variables were analyzed regarding the velocity and pressure of the fuel in the burners, the temperature of the combustion air and reactant gases, the conversion rate and the stoichiometric air/fuel ratio of the reaction. For the analysis, actual data of the furnace in operation was used, and for the simulation of chemical reactions, the software Gaseq® was used. The study showed that the adjustment of combustion reaction stoichiometry provides a reduction of 9.25% in fuel consumption, representing a savings of US$ 2.6 million per year for the company.

  8. Optimization of burners in oxygen-gas fired glass furnace

    NARCIS (Netherlands)

    Kersbergen, M.J. van; Beerkens, R.G.C.; Sarmiento-Darkin, W.; Kobayashi, H.

    2012-01-01

    The energy efficiency performance, production stability and emissions of oxygen-fired glass furnaces are influenced by the type of burner, burner nozzle sizes, burner positions, burner settings, oxygen-gas ratios and the fuel distribution among all the burners. These parameters have been optimized f

  9. Energy balance analysis for Erdemir blast furnace number one

    Energy Technology Data Exchange (ETDEWEB)

    M. Emre Ertem; Sabit Gurgen [Eregli Iron and Steel Works Inc., Zonguldak (Turkey). Energy Management Department

    2006-08-15

    There are two blast furnaces in Erdemir. The blast furnace No. 1, Ayse, started operations in 1965. Having been modernized three times in the years 1971, 1977, and 1986, it has been re-lined (the renewal of refractory bricks) in the year 1998. The diameter of its reservoir is 8.99 m with a working volume of 1505.0 m{sup 3}. The daily production capacity is 3000 tons amounting to 1,065,000 tons annually tons. The blast furnace No. 2, Zubeyde, started its operations in 1978. It has been modernized twice in the years 1987 and 1995 and has been re-lined in October 2000. It is of top pressure type and has oxygen injection. The diameter of its reservoir is 9.70 m with the working volume being 1707.7 m{sup 3}. The daily production capacity is 4000 tons with the annual being 1,420,000 tons. The iron production process consumes 50% of the total energy and comprises a significant portion of total costs in the integrated steel works. Iron (Fe) production is made by the reduction of hematite (Fe{sub 2}O{sub 3}) and magnetite (Fe{sub 3}O{sub 4}) with coke in the blast furnace. This can be analyzed as two separate areas, namely the furnace and stoves. The necessary carbon and high temperature required by the reduction process makes the furnaces an energy balance center. In this study, the limits of the Blast Furnace No. 1 in Erdemir have been chosen as the control volume in which the stoves have not been included. By the identification of the energy sources that move in and out of the control volume, the energy output sources have been fractioned and categorized. For the implementation of the method, also known as the balance analysis has been chosen and the model presented in the 'Japanese Steel Making Handbook' has been taken as a reference.

  10. Energy balance analysis for Erdemir blast furnace number one

    Energy Technology Data Exchange (ETDEWEB)

    Emre Ertem, M. [Eregli Iron and Steel Works Inc., Energy Management Department, 67330 Kdz. Eregli, Zonguldak (Turkey); Guergen, Sabit [Dokuz Eyluel University, Department of Mining Engineering, 35100 Bornova, Izmir (Turkey)

    2006-08-15

    Eregli Iron and Steel Works (Erdemir) began its activities on May 15, 1965 with an annual production capacity of 450,000 tons and has made important contributions to the Turkish economy ever since. Today, with a total amount of crude steel production exceeding three million tons, it is the largest integrated iron and steel factory and the sole producer of flat steel in the country. Erdemir produces hot and cold rolled coils, zinc, tin, and chromium plated steel. There are two blast furnaces in Erdemir. The blast furnace No. 1, Ayse, started operations in 1965. Having been modernized three times in the years 1971, 1977, and 1986, it has been re-lined (the renewal of refractory bricks) in the year 1998. The diameter of its reservoir is 8.99m with a working volume of 1505.0m{sup 3}. The daily production capacity is 3000 tons amounting to 1,065,000 tons annually tons. The blast furnace No. 2, Zubeyde, started its operations in 1978. It has been modernized twice in the years 1987 and 1995 and has been re-lined in October 2000. It is of top pressure type and has oxygen injection. The diameter of its reservoir is 9.70m with the working volume being 1707.7m{sup 3}. The daily production capacity is 4000 tons with the annual being 1,420,000 tons. The iron production process consumes 50% of the total energy and comprises a significant portion of total costs in the integrated steel works. Iron (Fe) production is made by the reduction of hematite (Fe{sub 2}O{sub 3}) and magnetite (Fe{sub 3}O{sub 4}) with coke in the blast furnace. This can be analyzed as two separate areas, namely the furnace and stoves. The necessary carbon and high temperature required by the reduction process makes the furnaces an energy balance center. In this study, the limits of the Blast Furnace No. 1 in Erdemir have been chosen as the control volume in which the stoves have not been included. By the identification of the energy sources that move in and out of the control volume, the energy output

  11. Status and Evaluation of Microwave Furnace Capabilities at NASA Glenn Research Center

    Science.gov (United States)

    Lizcano, Maricela; Mackey, Jonathan A.

    2014-01-01

    The microwave (MW) furnace is a HY-Tech Microwave Systems, 2 kW 2.45 GHz Single Mode Microwave Applicator operating in continuous wave (CW) with variable power. It is located in Cleveland, Ohio at NASA Glenn Research Center. Until recently, the furnace capabilities had not been fully realized due to unknown failure that subsequently damaged critical furnace components. Although the causes of the problems were unknown, an assessment of the furnace itself indicated operational failure may have been partially caused by power quality. This report summarizes the status of the MW furnace and evaluates its capabilities in materials processing.

  12. Design and Fabrication of a Stir Casting Furnace Set-Up

    Directory of Open Access Journals (Sweden)

    Manabhanjan Sahoo

    2015-07-01

    Full Text Available Now-a-days a large variety of heating techniques/furnaces are available. There may be many method for supplying heat to the work but heat is produced either by combustion of fuel or electric resistance heating. Taking into consideration the effect of cost, safety, simplicity and ease of construction we are going for an electrical resistance heating furnace with indirect heating provisions. The stir casting furnace has two main parts that enable to perform all its operations, they are: Furnace Elements and Control Panel. This paper shows the design and fabrication of stir-casting furnace and aluminium melted and casted to form.

  13. Numerical Computation of Net Radiative Heat Transfer within a Non Absorbing Furnace Enclosure

    Directory of Open Access Journals (Sweden)

    Shuaibu Ndache MOHAMMED

    2006-07-01

    Full Text Available The numerical evaluation of the net radiative heat transfer rate in a single zone, non absorbing furnace enclosure is reported. In this analysis, simplified mathematical furnace model namely, the long furnace model is used to determine furnace performance. The formulation assumes some known temperature values. Thus, heat transfer equations were set up and solved numerically. A FORTRAN computer program was developed and debugged. Results obtained from this study compare favourably well with the results from the traditional graphical method. Also, the computer program developed can handle variations in furnace operating conditions, temperatures, thermal properties and dimensions.

  14. Study of effect of electric arc furnace slag on expansion of mortars subjected to alkali-aggregate reaction

    Directory of Open Access Journals (Sweden)

    L. SOUZA

    Full Text Available Abstract Alkali-aggregate reaction is a chemical reaction between cement alkalis and some reactive mineral present in some aggregates, leading to concrete expansion and cracking. One kind usually observed and studied in Brazil is the alkali-silica reaction, due to its fast development. There are several methods that are effective to control and mitigate this reaction, and one of them is the partial replacement of cement by mineral additions such as pozzolans like fly-ash, silica fume and slag. In this study, we propose the use of electrical steel slag as a partial replacement of cement, evaluating its effectiveness by NBR 15577:2008, employing different proportions as replacement. It seems that the electrical steel slag, despite its expansive behavior, has been effective in the control of the ASR.

  15. Mathematical model on heat transfer of water-cooling steel-stick bottom electrode of DC electric arc furnace

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    For predicting and controlling the melted depth of bottom electrode during the process of steelmaking, the water-cooling steel-stick electrode is taken as an example, to analyze the process of heat transfer, then 3D mathematical model by control capacity method is built. At the same time, the measurement on the melted depth of bottom electrode is conducted which verified the correctness of the built mathematical model. On the base of verification, all kinds of key parameters are calculated through the application and a series of results are simulated. Finally, the optimum parameters are found and the service lifeof bottom electrode is prolonged.

  16. Mathematical Model on heat transfer of water—cooling steel—stick bottom electrode of DC electric arc furnace

    Institute of Scientific and Technical Information of China (English)

    HaiXu; XiaoLiu; 等

    2002-01-01

    For predicting and controlling the melted depth of bottom electrode during the process of steelmaking,the water-cooling steel stick electrode is taken as an example.to analyze the process of heat transfer,then 3D mathematical model by control capacity method is built.At the same time,the measurement on the melted depth of bottom electrode is conducted which verified the correctness of the built mathematical model.On the base of verification,all kinds of key parameters are calculated through the application and a series of results are simulated.Finally,the optimum parameters are found and the service life of bottom electrode is prolonged.

  17. Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces; La metalurgia del mercurio en Almaden: desde los hornos de aludeles a los hornos Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

    2014-07-01

    This paper shows the different types of furnaces for roasting cinnabar, used in the metallurgy of quicksilver over the centuries of exploitation of the Almaden Mines (Spain). Some of these techniques are part of our industrial heritage. They have contributed to name UNESCO World Heritage Site the vast technological legacy of these mines recently. This research contributes to close the long way of metallurgical activity from aludel furnaces until Pacif furnaces, first and lasted technology to produce on an industrial scale. It is delved into the most relevant aspects having to do with the type, evolution and number of furnaces existing on each of the periods. (Author)

  18. Towards a theory for Neptune's arc rings

    Science.gov (United States)

    Goldreich, P.; Tremaine, S.; Borderies, N.

    1986-01-01

    It is proposed that the incomplete rings of Neptune consist of a number of short arcs centered on the corotation resonances of a single satellite. The satellite must have a radius of the order of 100 km or more and move on an inclined orbit. Corotation resonances are located at potential maxima. Thus, mechanical energy dissipated by interparticle collisions must be continually replenished to prevent the arcs from spreading. It is shown that each corotation resonance is associated with a nearby Lindblad resonance, which excites the ring particles' orbital eccentricity, thus supplying the energy required to maintain the arc. The ultimate energy reservoir is the satellite's orbital energy. Therefore, interaction with the arcs damps the satellite's orbital inclination. The self-gravity of the arcs limits their contraction and enforces a relation between arc length and mass. The estimated arc masses are so small, of the order of 10 to the 16th g, that the satellite's orbital inclination suffers negligible decay over the age of the solar system. The inferred surface mass densities are comparable to those found in the major rings of Saturn and Uranus.

  19. Contribution For Arc Temperature Affected By Current Increment Ratio At Peak Current In Pulsed Arc

    Science.gov (United States)

    Kano, Ryota; Mitubori, Hironori; Iwao, Toru

    2015-11-01

    Tungsten Inert Gas (TIG) Welding is one of the high quality welding. However, parameters of the pulsed arc welding are many and complicated. if the welding parameters are not appropriate, the welding pool shape becomes wide and shallow.the convection of driving force contributes to the welding pool shape. However, in the case of changing current waveform as the pulse high frequency TIG welding, the arc temperature does not follow the change of the current. Other result of the calculation, in particular, the arc temperature at the reaching time of peak current is based on these considerations. Thus, the accurate measurement of the temperature at the time is required. Therefore, the objective of this research is the elucidation of contribution for arc temperature affected by current increment ratio at peak current in pulsed arc. It should obtain a detail knowledge of the welding model in pulsed arc. The temperature in the case of increment of the peak current from the base current is measured by using spectroscopy. As a result, when the arc current increases from 100 A to 150 A at 120 ms, the transient response of the temperature didn't occur during increasing current. Thus, during the current rise, it has been verified by measuring. Therefore, the contribution for arc temperature affected by current increment ratio at peak current in pulsed arc was elucidated in order to obtain more knowledge of welding model of pulsed arc.

  20. Reconstruction of Late Cretaceous Magmatic Arcs in the Northern Andes: Single Versus Multiple Arc Systems

    Science.gov (United States)

    Cardona, A.; Jaramillo, J. S.; Leon, S.; Hincapie, S.; Mejia, D.; Patino, A. M.; Vanegas, J.; Zapata, S.; Valencia, V.; Jimenez, G.; Monsalve, G.

    2014-12-01

    Although magmatic rocks are major tracers of the geological evolution of convergent margins, pre-collisional events such as subduction erosion, collisional thrusting or late collisional strike slip segmentation may difficult the recognizing of multiple arc systems and therefore the existence of paleogeographic scenarios with multiple subduction systems. New field, U-Pb geochronology and whole rock geochemistry constraints from the northwestern segment of the Central Cordillera in the states of Antioquia and Caldas (Colombia) are used to understand the nature of the Late Cretaceous arc magmatism and evaluate the existence of single or multiple Pacific and Caribbean arc systems in the growth of the Northwestern Andes. The new results integrated with additional field and published information is used to suggest the existence of at least three different magmatic arcs. (1) An Eastern Continental arc built within a well defined Permian to Triassic continental crust that record a protracted 90-70 Ma magmatic evolution, (2) a 90-80 arc formed within attenuated continental crust and associated oceanic crust, (3) 90-88 Ma arc formed over a Late Cretaceous plateau crust. The eastern arcs were formed as part of double eastern vergent subduction system, where the most outboard arc represent a fringing arc formed over detached fragments of continental crust, whereas the easternmost continental arc growth by the closure an subduction of and older and broad Triassic to Early Jurassic back-arc ocean. Its closure also end up in ophiolite emplacement. The third allochtonous oceanic arc was formed over the Caribbean plateau crust and was accreted to the continental margin in the Late Cretaceous. Ongoing paleomagnetic, deformational, gravimetric and basin analysis will be integrate to test this model and understand the complex Late Cretaceous tectonic evolution of the Northern Andes.

  1. Investigation of Furnace Uniformity and its Effect on High-Temperature Fixed-Point Performance

    Science.gov (United States)

    Khlevnoy, B.; Sakharov, M.; Ogarev, S.; Sapritsky, V.; Yamada, Y.; Anhalt, K.

    2008-02-01

    A large-area furnace BB3500YY was designed and built at the VNIIOFI as a furnace for high-temperature metal (carbide)-carbon (M(C)-C) eutectic fixed points and was then investigated at the NMIJ. The dependence of the temperature uniformity of the furnace on various heater and cell holder arrangements was investigated. After making some improvements, the temperature of the central part of the furnace was uniform to within 2K over a length of 40 mm—the length of the fixed-point cell—at a temperature of 2,500°C. With this furnace, the melting plateaux of Re-C and TiC-C were shown to be better than those observed in other furnaces. For instance, a Re-C cell showed melting plateaux with a 0.1K melting range and a duration of about 40 min. Furthermore, to verify the capability of the furnace to fill cells, one Re-C and one TiC-C cell were made using the BB3500YY. The cells were then compared to a Re-C cell made in a Nagano furnace and a TiC-C cell filled in a BB3200pg furnace. The agreement in plateau shapes demonstrates the capability of the BB3500YY furnace to also function as a filling furnace.

  2. Measurement method and experimental research on flame emissivity in Coal-fired furnaces

    Institute of Scientific and Technical Information of China (English)

    YANG Chao; LOU Chun; JIANG Zhi-wei; ZHOU Huai-chun

    2007-01-01

    The combustion condition in coal-fired furnaces of the large power station boiler is very complex and the flame emissivity is one of the important combustion parameters.A measurement method of the flame emissivity based on the blackbody furnace calibration of CCD(Charge Coupled Device)cameras and the color image processing techniques of computer was introduced.The experimentaI research on the flame emissivity in a 200 MW boiler furnace and a 300 MW boiler furnace was conducted respectively through the several CCD cameras installed at different height in furnace.The measurement results show:the flame emissivity increases with the increase of the unit load.the flame emissivity of the burner areas in furnace is the highest and the flame emissivity decrease with the increase of height of furnace above the burners area.

  3. Carbothermal reduction process of silica formed from shirasu volcanic ash using solar furnace

    Directory of Open Access Journals (Sweden)

    Hatakeyama Keisuke

    2016-01-01

    Full Text Available Metallurgical grade silicon was formed using Shirasu volcanic ash as starting material with solar furnace. The solar furnace was composed of two parts: Fresnel lens and reacting furnace. The reacting furnace was composed of a cylindrical vacuum chamber and quartz glass plate functioning to guide the concentrated sunlight into the furnace, and was placed at the focal point of the Fresnel lens. The sample was made from a mixture of silica formed from Shirasu volcanic ash and carbon, and placed in the carbon crucible inside the reacting furnace. The sample was irradiated for 3 hours, and the furnace was left until it cooled down to room temperature. After the cooling process, the sample was mixed and placed in the carbon crucible, and it was irradiated and cooled with the same processes again. After the experiment, the sample was evaluated by X-ray diffraction and the production of silicon was confirmed.

  4. The Global Array of Primitve Arc Melts

    Science.gov (United States)

    Schmidt, M. W.; Jagoutz, O. E.

    2015-12-01

    A longstanding question concerns the nature of the melts forming in the subarc mantle and giving rise to arc magmatism. The global array of primitive arc melts (1180 volcanic rocks in 25 arcs extracted from the georoc database, calculated to be in equilibrium with mantle olivine) yields five principal melt types: calc-alkaline basalts and high-Mg andesites, tholeiitic basalts and high-Mg andesites, and shoshonitic or alkaline arc melts; many arcs have more than one type. Primitive calc-alkaline basalts occur in 11 arcs but most strikingly, 8 continental arcs (incl. Aleutians, Cascades, Japan, Mexico, Kamtschatka) have a continuous range of calc-alkaline basalts to high-Mg andesites with mostly 48-58 wt% SiO2. In each arc, these are spatially congruent, trace element patterns overlap, and major elements form a continuum. Their Ca-Mg-Si systematics suggests saturation in olivine+opx+cpx. We hence interpret the large majority of high-Mg andesites as derived from primitive calc-alkaline basalts through fractionation and reaction in the shallower mantle. Removal of anhydrous mantle phases at lower pressures increases SiO2 and H2O-contents while Mg# and Ni remain buffered to mantle values. Primitive tholeiitic basalts (Cascades, Kermadec, Marianas, Izu-Bonin, Japan, Palau, Sunda) have a much lesser subduction signal (e.g. in LILE) than the calc-alkaline suite. These tholeiites have been interpreted to form through decompression melting, but also characterize young intraoceanic arcs. In the two continental arcs with both tholeiitic and calc-alkaline primitive basalts (clearly distinct in trace patterns), there is no clear spatial segregation (Casacades, Japan). Three intraoceanic arcs (Marianas, Izu-Bonin, Tonga) have primitive tholeiitic, highly depleted high-Mg andesites (boninites) with HFSE and HREE slightly above primitive mantle values. These deviate in majors from the array formed by the basalts and calc-alkaline andesites suggesting that only these formed from a

  5. Formation of the G-ring arc

    Science.gov (United States)

    Araujo, N. C. S.; Vieira Neto, E.; Foryta, D. W.

    2016-09-01

    Since 2004, the images obtained by the Cassini spacecraft's on-board cameras have revealed the existence of several small satellites in the Saturn system. Some of these small satellites are embedded in arcs of particles. While these satellites and their arcs are known to be in corotation resonances with Mimas, their origin remains unknown. This work investigates one possible process for capturing bodies into a corotation resonance, which involves increasing the eccentricity of a perturbing body. Therefore, through numerical simulations and analytical studies, we show a scenario in which the excitation of Mimas's eccentricity could capture particles in a corotation resonance. This is a possible explanation for the origin of the arcs.

  6. Formation of the G-ring arc

    CERN Document Server

    Araujo, N C S; Foryta, D W

    2016-01-01

    Since 2004, the images obtained by Cassini spacecraft's on-board cameras have revealed the existence of several small satellites in the Saturn system. Some of these small satellites are embedded in arcs of particles. While these satellites and their arcs are known to be in corotation resonances with Mimas, their origin remains unknown. This work investigates one possible process for capturing bodies into a corotation resonance, which involves raising the eccentricity of a perturbing body. Therefore, through numerical simulations and analytical studies, we show a scenario that the excitation of Mimas' eccentricity could capture particles in a corotation resonance and given a possible explanation for the origin for the arcs.

  7. Cathodic Vacuum Arc Plasma of Thallium

    OpenAIRE

    Yushkov, Georgy Yu.; Anders, Andre

    2006-01-01

    Thallium arc plasma was investigated in a vacuum arc ion source. As expected from previous consideration of cathode materials in the Periodic Table of the Elements, thallium plasma shows lead-like behavior. Its mean ion charge state exceeds 2.0 immediately after arc triggering, reaches the predicted 1.60 and 1.45 after about 100 microsec and 150 microsec, respectively. The most likely ion velocity is initially 8000 m/s and decays to 6500 m/s and 6200 m/s after 100 microsec and 150 micros...

  8. Linear volcanic segments in the Sunda Arc, Indonesia: Implications for arc lithosphere control upon volcano distribution

    Science.gov (United States)

    Macpherson, C. G.; Pacey, A.; McCaffrey, K. J.

    2012-12-01

    The overall curvature of many subduction zones is immediately apparent and the term island arc betrays the common assumption that subduction zone magmatism occurs in curved zones. This assumption can be expressed by approximating island arcs as segments of small circles on the surface of a sphere. Such treatments predict that the location of arc volcanoes is related to their vertical separation from the slab (in fact, the depth to seismicity in the slab) and require that the primary control on the locus of magmatism lies either within the subducted slab or the mantle wedge that separates the subducted and overriding lithospheric plates. The concept of curved arcs ignores longstanding observations that magmatism in many subduction systems occurs as segments of linearly arranged volcanic centres. Further evidence for this distribution comes from the close relationship between magmatism and large scale, arc-parallel fabrics in some arcs. Similarly, exposures of deep arc crust or mantle often reveal elongation of magmatic intrusions sub-parallel to the inferred trend of the arc. The Sunda Arc forms the Indonesian islands from Sumatra to Alor and provides an important test for models of volcano distribution for several reasons. First, Sunda has hosted abundant historic volcanic activity. Second, with the notable exception of Krakatau, every volcano in the arc is subaerial from base to cone and, therefore, can be readily identified where there is a suitable extent of local mapping that can be used to ground-truth satellite imagery. Third, there are significant changes in the stress regime along the length of the arc, allowing the influence of the upper plate to be evaluated by comparison of different arc segments. Finally, much of the Sunda Arc has proved difficult to accommodate in models that try to relate volcano distribution to the depth to the subducted slab. We apply an objective line-fitting protocol; the Hough Transform, to explore the distribution of volcanoes

  9. CFD simulation of gas and particles combustion in biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Griselin, Nicolas

    2000-11-01

    In this thesis, gas and particle combustion in biomass furnaces is investigated numerically. The aim of this thesis is to use Computational Fluid Dynamics (CFD) technology as an effective computer based simulation tool to study and develop the combustion processes in biomass furnaces. A detailed model for the numerical simulation of biomass combustion in a furnace, including fixed-bed modeling, gas-phase calculation (species distribution, temperature field, flow field) and gas-solid two-phase interaction for flying burning particles is presented. This model is used to understand the mechanisms of combustion and pollutant emissions under different conditions in small scale and large scale furnaces. The code used in the computations was developed at the Division of Fluid Mechanics, LTH. The flow field in the combustion enclosure is calculated by solving the Favre-averaged Navier-Stokes equations, with standard {kappa} - {epsilon} turbulence closure, together with the energy conservation equation and species transport equations. Discrete transfer method is used for calculating the radiation source term in the energy conservation equation. Finite difference is used to solve the general form of the equation yielding solutions for gas-phase temperatures, velocities, turbulence intensities and species concentrations. The code has been extended through this work in order to include two-phase flow simulation of particles and gas combustion. The Favre-averaged gas equations are solved in a Eulerian framework while the submodels for particle motion and combustion are used in the framework of a Lagrangian approach. Numerical simulations and measurement data of unburned hydrocarbons (UHC), CO, H{sub 2}, O{sub 2} and temperature on the top of the fixed bed are used to model the amount of tar and char formed during pyrolysis and combustion of biomass fuel in the bed. Different operating conditions are examined. Numerical calculations are compared with the measured data. It is

  10. Prostate treatments, 1MRT o RapidArc; Tratamiento de prostata, IMART o RapidArc?

    Energy Technology Data Exchange (ETDEWEB)

    Castro novais, J.; Ruiz Maqueda, S.; Pardo Perez, E.; Molina Lopez, M. Y.; Cerro Penalver, E.

    2015-07-01

    Techniques that modulate the dose (as IMRT or RapidArcTM) improve dose homogeneity within the target volume decreasing the dose in healthy organs. The aim of this work is to study the dosimetric differences in prostate radiotherapy treatments with IMRT and RapidArcTM. The results of the 109 patients studied show that plans to RapidArcTM have better coverage, compliance and dose gradient outside the target volume. (Author)

  11. Seward, Alaska 3 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 3 arc-second Seward Alaska Elevation Grid provides bathymetric data in ASCII raster format of 2.67-second resolution in geographic coordinates. This grid is...

  12. Observation of gliding arc surface treatment

    DEFF Research Database (Denmark)

    Kusano, Yukihiro; Zhu, Jiajian; Ehn, A.

    2015-01-01

    . Water contact angle measurements indicate that the treatment uniformity improves significantly when the AC gliding arc is tilted to the polymer surface. Thickness reduction of the gas boundary layer, explaining the improvement of surface treatment, by the ultrasonic irradiation was directly observed......An alternating current (AC) gliding arc can be conveniently operated at atmospheric pressure and efficiently elongated into the ambient air by an air flow and thus is useful for surface modification. A high speed camera was used to capture dynamics of the AC gliding arc in the presence of polymer...... surfaces. A gap was observed between the polymer surface and the luminous region of the plasma column, indicating the existence of a gas boundary layer. The thickness of the gas boundary layer is smaller at higher gas flow-rates or with ultrasonic irradiation to the AC gliding arc and the polymer surface...

  13. Arc tracks on nanostructured surfaces after microbreakdowns

    Science.gov (United States)

    Sinelnikov, D.; Bulgadaryan, D.; Hwangbo, D.; Kajita, S.; Kolodko, D.; Kurnaev, V.; Ohno, N.

    2016-09-01

    Studying of initial steps of unipolar arc ignition process is important for reduction of probability of arcing between the plasma and the wall in thermonuclear devices. Tungsten nano-fuzz surface formed by helium plasma irradiation at high fluences and temperatures is a perfect material for arc ignition. Snowflake-like craters were detected on the fuzzy surfaces after short micro-breakdowns. Such sort of craters have not been observed before on any other metallic surfaces. These specific traces are formed due to unique properties of the fuzz structure. The nano-fuzz could be easily melted and vaporized by micro-breakdown current, due to its porosity and bad thermal conductivity, and formation of low conducting metallic vapour under the cathode spot causes discharge movement to the nearest place. Thus, even low current arc can easily move and leave traces, which could be easily observed by a secondary electron microscope.

  14. Seward, Alaska 1 arc-second DEM

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1 arc-second Seward Alaska Elevation Grid provides bathymetric data in ASCII raster format of .89-second resolution in geographic coordinates. This grid is...

  15. Effect of arc on radiation thermometry in welding process

    Institute of Scientific and Technical Information of China (English)

    李亮玉; 王燕; 武宝林

    2002-01-01

    The effect of arc on radiation thermometry is analyzed in a field close to the arc during the welding process, and the ratio of signal to noise and other factors are obtained for a small current arc .The method of the temperature measurement is feasible when the arc current is decreased to a smaller value in the welding process.

  16. Resistance Characteristics of Arc in Long Air Gap

    Institute of Scientific and Technical Information of China (English)

    YU Zhanqing; YU Junjie; ZENG Rong; CHEN He; PENG Xiang

    2013-01-01

    Arc resistance is an important parameter for characterizing long arcs in air,and its laboratory testing is of importance for accurate arc modeling of electromagnetic transient caused by short circuit fault.Therefore,we constructed an experimental system to study the characteristics of long AC arc in air.Driven by currents of 10 kA or 40 kA (root mean square value),the system produces arcs with different initial lengths of 1 m,2 m and 4 m,and the movement of the arcs are captured by a high-speed camera.After performing experiments using the system,we carried out analysis and comparisons of the arc resistance of arcs with different lengths and different currents,as well as a study of the relationship between the macro-morphology and the resistance of the arcs.Conclusions were drawn from the experimental results:the arc voltage had obvious saturation characteristics; the arc resistance increased with the increase of arc length and the decrease of current; the arcs bended or extended significantly in time and the peak arc voltage within a single cycle increased correspondingly; the arcs had voltage and current in the same phase.In the end,a formula of arc resistance based on the experiment results is derived.

  17. Palaeomagnetic constraints on the geodynamic evolution of the Gibraltar Arc

    NARCIS (Netherlands)

    Krijgsman, W.; Garces, M.

    2004-01-01

    Subduction zone roll-back was recently put forward as a convincing model to explain the geometry and evolution of the Gibraltar Arc. For other subduction-related arc systems of the Mediterranean, such as the Calabrian Arc and the Hellenic Arc, palaeomagnetic rotation data from Neogene extensional ba

  18. 49 CFR 195.226 - Welding: Arc burns.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Arc burns. 195.226 Section 195.226 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.226 Welding: Arc burns. (a) Each arc burn must be repaired. (b) An arc burn...

  19. Basins in ARC-continental collisions

    Science.gov (United States)

    Draut, Amy E.; Clift, Peter D.; Busby, Cathy; Azor, Antonio

    2012-01-01

    Arc-continent collisions occur commonly in the plate-tectonic cycle and result in rapidly formed and rapidly collapsing orogens, often spanning just 5-15 My. Growth of continental masses through arc-continent collision is widely thought to be a major process governing the structural and geochemical evolution of the continental crust over geologic time. Collisions of intra-oceanic arcs with passive continental margins (a situation in which the arc, on the upper plate, faces the continent) involve a substantially different geometry than collisions of intra-oceanic arcs with active continental margins (a situation requiring more than one convergence zone and in which the arc, on the lower plate, backs into the continent), with variable preservation potential for basins in each case. Substantial differences also occur between trench and forearc evolution in tectonically erosive versus tectonically accreting margins, both before and after collision. We examine the evolution of trenches, trench-slope basins, forearc basins, intra-arc basins, and backarc basins during arc-continent collision. The preservation potential of trench-slope basins is low; in collision they are rapidly uplifted and eroded, and at erosive margins they are progressively destroyed by subduction erosion. Post-collisional preservation of trench sediment and trench-slope basins is biased toward margins that were tectonically accreting for a substantial length of time before collision. Forearc basins in erosive margins are usually floored by strong lithosphere and may survive collision with a passive margin, sometimes continuing sedimentation throughout collision and orogeny. The low flexural rigidity of intra-arc basins makes them deep and, if preserved, potentially long records of arc and collisional tectonism. Backarc basins, in contrast, are typically subducted and their sediment either lost or preserved only as fragments in melange sequences. A substantial proportion of the sediment derived from

  20. Proposition of a modification to the VAR process and its application in the consolidation of pressed zircaloy chips and the evaluation of the dynamical system of the electric arc; Proposicao de um processo alternativo a fusao via forno VAR para a consolidacao de cavacos prensados de zircaloy e estudo do sistema dinamico do arco eletrico

    Energy Technology Data Exchange (ETDEWEB)

    Mucsi, Cristiano Stefano

    2005-07-01

    The objective of this work is the investigation of a new process as an alternative to the Vacuum Arc Remelting technology in the consolidation of Zircaloy chips. A procedure is proposed for the recycling of primary Zircaloy scraps by means of a modified VAR furnace. The performed studies were made in order to optimise the low cost new devices added to existing VAR furnace prototype, find ideal operational conditions, evaluate data acquisition system and the electric arc dynamical system in order to made viable the automated control of the modified VAR prototype. A funnel-crucible special device was developed and installed in a VAR prototype furnace allowing ingots to be obtained from pressed chips. This indicated the viability of creation of a new process for the consolidation of Zircaloy chips. The voltage of the electric arc during the melting runs was digitally recorded allowing the evaluation of the electric arc dynamics by using the topological invariant of the system: correlation dimension and the higher Liapunov exponent. (author)