Graphite electrode DC arc furnace. Innovative technology summary report

International Nuclear Information System (INIS)

1999-05-01

The Graphite Electrode DC Arc Furnace (DC Arc) is a high-temperature thermal process, which has been adapted from a commercial technology, for the treatment of mixed waste. A DC Arc Furnace heats waste to a temperature such that the waste is converted into a molten form that cools into a stable glassy and/or crystalline waste form. Hazardous organics are destroyed through combustion or pyrolysis during the process and the majority of the hazardous metals and radioactive components are incorporated in the molten phase. The DC Arc Furnace chamber temperature is approximately 593--704 C and melt temperatures are as high as 1,500 C. The DC Arc system has an air pollution control system (APCS) to remove particulate and volatiles from the offgas. The advantage of the DC Arc is that it is a single, high-temperature thermal process that minimizes the need for multiple treatment systems and for extensive sorting/segregating of large volumes of waste. The DC Arc has the potential to treat a wide range of wastes, minimize the need for sorting, reduce the final waste volumes, produce a leach resistant waste form, and destroy organic contaminants. Although the DC arc plasma furnace exhibits great promise for treating the types of mixed waste that are commonly present at many DOE sites, several data and technology deficiencies were identified by the Mixed Waste Focus Area (MWFA) regarding this thermal waste processing technique. The technology deficiencies that have been addressed by the current studies include: establishing the partitioning behavior of radionuclides, surrogates, and hazardous metals among the product streams (metal, slag, and offgas) as a function of operating parameters, including melt temperature, plenum atmosphere, organic loading, chloride concentration, and particle size; demonstrating the efficacy of waste product removal systems for slag and metal phases; determining component durability through test runs of extended duration, evaluating the effect of

Graphite electrode DC arc furnace system for treatment of environmentally undesirable solid waste

International Nuclear Information System (INIS)

Titus, C.H.

1993-01-01

A gas tight DC arc furnace system using graphite electrodes is ideally suited for destruction of organic materials, compaction of metallic materials, and vitrification of inorganic waste materials. A graphite electrode DC arc furnace system which was developed by Electro-Pyrolysis, Inc. has been used to demonstrate that iron basalt soil containing various surrogate nonradioactive materials found on Department of Energy's Atomic Energy Sites and hospital waste can be reduced to a compact, vitrified, solid material which is environmentally acceptable and will pass TCLP leachate tests. A second graphite electrode DC arc furnace system is presently under construction and will be in operation at MIT during the second quarter of 1993. This furnace system is designed for demonstration of waste treatment and stabilization at a rate of 500 pounds per hour and will also be used for development and performance evaluation of diagnostic techniques and equipment for measuring and understanding internal furnace temperature profiles, gas entrained particulate composition, and particulate size distribution in various locations in the furnace during operation

Method of operating a centrifugal plasma arc furnace

International Nuclear Information System (INIS)

Kujawa, S.T.; Battleson, D.M.; Rademacher, E.L. Jr.; Cashell, P.V.; Filius, K.D.; Flannery, P.A.; Whitworth, C.G.

1998-01-01

A centrifugal plasma arc furnace is used to vitrify contaminated soils and other waste materials. An assessment of the characteristics of the waste is performed prior to introducing the waste into the furnace. Based on the assessment, a predetermined amount of iron is added to each batch of waste. The waste is melted in an oxidizing atmosphere into a slag. The added iron is oxidized into Fe 3 O 4 . Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe 2 O 3 . Slag in the furnace remains relatively non-viscous and consequently it pours out of the furnace readily. Cooled and solidified slag produced by the furnace is very resistant to groundwater leaching. The slag can be safely buried in the earth without fear of contaminating groundwater. 3 figs

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

International Nuclear Information System (INIS)

Surma, J.E.; Lawrence, W.E.; Titus, C.H.; Wittle, J.K.; Hamilton, R.A.; Cohn, D.R.; Rhea, D.; Thomas, P.; Woskov, P.P.

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-Industryclose 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

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.

Use of refractory chromites for obtaining fluxes amassed employed in submerged arc welding (SAW); Empleo de cromitas refractarias par la obtencion de fundentes aglomerados utilizados en la soldadura automatica por arco sumegido (SAW)

Energy Technology Data Exchange (ETDEWEB)

Perdomo-Gonzalez, L.; Quintana-Puchol, R.; Cruz-Crespo, A.; Castellanos-Estupinan, J.; Garcia-Sanchez, L. L.; Formoso-Prego, A.; Cores-Sanchez, A.

2003-07-01

In the present work high carbon ferrochrome (load ferrochrome) and slags are obtained, starting from the metallurgic reductive processing of refractory chromites. The obtaining of alloys and slags is studied using an experiment design based in the relationships among components. The chemical compositions of alloys and slags guarantee their application for the conformation of alloys loads and matrix fluxes amassed for the superficial filling by means of submerged arc welding (SAW). The melting-reduction process is carried out in an electric arc furnace. (Author) 16 refs.

Simulation of a DC electric arc furnace for steelmaking: study in the arc and bath regions

International Nuclear Information System (INIS)

Ramirez Argaez, M. A.; Trapaga Martinez, L. G.

2001-01-01

A mathematical model was developed to describe fluid flow, heat transfer, and electromagnetic phenomena in the arc and bath regions of DC electric Arc Furnaces (DC-EAF). The model is used to examine the effect on flow patterns and temperature distribution in the bath, under the influence of both an arc and bottom argon injection in steel or steel/slag systems. Validation of the model employed experimental measurements from systems physically related to DC-EAF from literature. For the conditions analyzed, electromagnetic forces dominate the fluid motion in the bath. Buoyancy and shear forces from the arc have a negligible effect in driving the flow; however, they partially counteract the electromagnetic forces. Slag decreases fluid motion in the steel and enhances temperature stratification in the system. Stirring of the bath, using a 3-nozzle inert gas injection system, is found to promote temperature uniformity in the regions near the lateral wall of the furnace. (Author) 24 refs

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.

Methods of steel manufacturing - The electric arc furnace

Science.gov (United States)

Dragna, E. C.; Ioana, A.; Constantin, N.

2018-01-01

Initially, the carbon content was reduced by mixing “the iron” with metallic ingots in ceramic crucibles/melting pots, with external heat input. As time went by the puddling procedure was developed, a procedure which also assumes a mixture with oxidized iron ore. In 1856 Bessemer invented the convertor, thus demonstrating that steel can be obtained following the transition of an air stream through the liquid pig iron. The invention of Thomas, a slightly modified basic-lined converter, fostered the desulphurization of the steel and the removal of the phosphate from it. During the same period, in 1865, in Sireuil, the Frenchman Martin applies Siemens’ heat regeneration invention and brings into service the furnace with a charge composed of iron pig, scrap iron and iron ore, that produces a high quality steel [1]. An act worthy of being highlighted within the scope of steelmaking is the start-up of the converter with oxygen injection at the upper side, as there are converters that can produce 400 tons of steel in approximately 50 minutes. Currently, the share of the steel produced in electric arc furnaces with a charge composed of scrap iron has increased. Due to this aspect, the electric arc furnace was able to impose itself on the market.

Improved cooler design of electric arc furnace refractory in mining industry using thermal analysis modeling and simulation

International Nuclear Information System (INIS)

Istadi, I.; Bindar, Y.

2014-01-01

Production of steel and nickel using the electric arc furnace should be focused on the intensification of energy. Improvement of energy efficiency of the most consuming facilities was achieved by improving the use of alternative energy minimization such as reducing the heat lost of hot gases, minimizing the heat radiated through refractory linings of metallurgical furnaces, and cooling the highly thermally stressed components. The refractory of electric arc furnace should be modified to achieve the best cooling system of the furnace. In this physical modeling and simulation works, four modification scenarios of wall refractory designs were simulated, i.e. refractory with basic design, refractory with deep plate coolers, refractory with extra plate coolers, and refractory with wall falling film coolers. Finally, the use of deep plate cooler and the existing waffle cooler system was considered to be the best design of efficient electric arc furnace operationally. - Highlights: • Electric arc furnace design should be focused on the intensification of energy. • Refractory of electric arc furnace were modified to achieve the best cooling system. • Four modification scenarios of the wall refractory designs were simulated. • Use of deep plate cooler and existing waffle cooler system is the best cooling

Plasma arc and cold crucible furnace vitrification for medium level waste: a review

International Nuclear Information System (INIS)

Poitou, S.; Fiquet, O.; Bourdeloie, C.; Gramondi, P.; Rebollo, F.; Girold, C.; Charvillat, J.P.; Boen, R.; Jouan, A.; Ladirat, C.; Nabot, J.P.; Ochem, D.; Baronnet, J.M.

2001-01-01

Initially developed for high-level waste reprocessing, several vitrification processes have been under study since the 80's at the French Atomic Energy Commission (CEA) for other waste categories. According to the French law concerning waste management research passed on December 30, 1991, vitrification may be applied to mixed medium-level waste. A review of processes developed at CEA is presented: cold crucible furnace heated by induced current, refractory furnace heated by nitrogen transferred arc plasma torch, and coupling of cold crucible furnace with oxygen transferred plasma arc twin torch. Furthermore, gas post-combustion has been studied with an oxygen non-transferred plasma torch. (authors)

Power quality analysis of DC arc furnace operation using the Bowman model for electric arc

Science.gov (United States)

Gherman, P. L.

2018-01-01

This work is about a relatively new domain. The DC electric arc is superior to the AC electric arc and it’s not used in Romania. This is why we analyzed the work functions of these furnaces by simulation and model checking of the simulation results.The conclusions are favorable, to be carried is to develop a real-time control system of steel elaboration process.

A novel estimation of electrical and cooling losses in electric arc furnaces

International Nuclear Information System (INIS)

Trejo, Eder; Martell, Fernando; Micheloud, Osvaldo; Teng, Lidong; Llamas, Armando; Montesinos-Castellanos, Alejandro

2012-01-01

A method to calculate electrical losses and a heat transfer model of a conventional Electric Arc Furnace (EAF) are presented. The application of a novel power theory for the EAF was used to compute electrical losses and it was compared with conventional power calculations. The electrical losses and electrical variables were used as input parameters to the proposed heat transfer model. Chemical energy sources were included as energy inputs to estimate the overall heat transferred including the heat losses in the cooling system. In the heat transfer model the furnace was divided in 11 inner surfaces and the radiation view factors between them were estimated by a commercial finite element software. Variations of the view factors for different arc coverage were evaluated. Different scenarios for cooling panels losses, with respect to arc coverage and thickness of slag layers adhered to cooling system panels, were analyzed. The approach presented in this work allows calculation of energy balances in electrical arc furnaces with low computational resources. Finally, the contribution of this research work is to define a framework for further research oriented to improve both the electrical and thermal energy efficiencies to increase productivity and reduce energy consumption in steel plants. -- Highlights: ► Radiation view factors for the electric arc furnace are estimated. ► Potential reduction in cooling losses is estimated to be 60 kWh/ton. ► Electrical losses are calculated based in the randomness power theory. ► The new approach yields an increase of 10% in the electrical losses. ► An analytic model is used to estimate the radiation mechanism.

Nonlinear system identification of the reduction nickel oxide smelting process in electric arc furnace

Science.gov (United States)

Gubin, V.; Firsov, A.

2018-03-01

As the title implies the article describes the nonlinear system identification of the reduction smelting process of nickel oxide in electric arc furnaces. It is suggested that for operational control ratio of components of the charge must be solved the problem of determining the qualitative composition of the melt in real time. The use of 0th harmonic of phase voltage AC furnace as an indirect measure of the melt composition is proposed. Brief description of the mechanism of occurrence and nature of the non-zero 0th harmonic of the AC voltage of the arc is given. It is shown that value of 0th harmonic of the arc voltage is not function of electrical parameters but depends of the material composition of the melt. Processed industrial data are given. Hammerstein-Wiener model is used for description of the dependence of 0th harmonic of the furnace voltage from the technical parameters of melting furnace: the melt composition and current. Recommendations are given about the practical use of the model.

Hydrometallurgical process for zinc recovery from electric arc furnace dust (EAFD)

International Nuclear Information System (INIS)

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

2010-01-01

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.

Design and analysis of high current DC power supply for vacuum arc melting furnace

International Nuclear Information System (INIS)

Adhikary, Santu; Sharma, Vishnu Kumar; Sharma, Archana

2015-01-01

Vacuum Arc furnace (VAR), is used for melting of ingot in many industrial units. Till now in many industries the existing power supply for VAR is based on magnetic amplifier, which is a lossy component. Thus an efficient topology is needed to develop as a suitable alternative for the existing power supply. Basically Arc in electrical furnace is an unstable phenomena, it has drooping characteristic in nature so to stabilize the arc we need a power supply across the load (arc), which is more drooping in nature than arc characteristics. So this paper highlights the stability and response analysis of several alternative topologies and Stabilization of arc using the feedback and firing angle control in MATLAB. The work also covers comparison among those topologies to choose the optimized topology as a suitable alternative of the existing magnetic amplifier based power supply and the detail design of the proposed topology with a tested trail circuit in PROTEUS. (author)

Application of gas shielded arc welding and submerged arc welding for fabrication of nuclear reactor vessels

International Nuclear Information System (INIS)

Gehani, M.L.; Rodrigues, W.D.

1976-01-01

The remarkable progress made in the development of knowhow and expertise in the manufacture of equipment for nuclear power plants in India is outlined. Some of the specific advances made in the application of higher efficiency weld processes for fabrication of nuclear reactor vessels and the higher level of quality attained are discussed in detail. Modifications and developments in submerged arc, gas tungsten arc and gas metal arc processes for welding of Calandria which have been a highly challenging and rewarding experience are discussed. Future scope for making the gas metal arc process more economical by using various gas-mixes like Agron + Oxygen, Argon + Carbon Dioxide, Argon + Nitrogen (for Copper Alloys) etc., in various proportions are outlined. Quality and dimensional control exercised in these jobs of high precision are highlighted. (K.B.)

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.

Evaluation of the graphite electrode DC arc furnace for the treatment of INEL buried wastes

International Nuclear Information System (INIS)

Surma, J.E.; Freeman, C.J.; Powell, T.D.; Cohn, D.R.; Smatlak, D.L.; Thomas, P.; Woskov, P.P.

1993-06-01

The past practices of DOE and its predecessor agencies in burying radioactive and hazardous wastes have left DOE with the responsibility of remediating large volumes of buried wastes and contaminated soils. The Buried Waste Integrated Demonstration (BWID), has chosen to evaluate treatment of buried wastes at the Idaho National Engineering Laboratory (INEL). Because of the characteristics of the buried wastes, the potential for using high-temperature thermal treatment technologies is being evaluated. The soil-waste mixture at INEL, when melted or vitrified, produces a glass/ceramic referred to as iron-enriched basalt (IEB). One potential problem with producing the IEB material is the high melting temperature of the waste and soil (1,400-1,600 degrees C). One technology that has demonstrated capabilities to process high melting point materials is the plasma arc heated furnace. A three-party program was initiated and the program involved testing an engineering-scale DC arc furnace to gain preliminary operational and waste processibility information. It also included the design, fabrication, and evaluation of a second-generation, pilot-scale graphite electrode DC arc furnace. Widely ranging simulants of INEL buried waste were prepared and processed in the Mark I furnace. The tests included melting of soils with metals, sludges, combustibles, and simulated drums. Very promising results in terms of waste product quality, volume reduction, heating efficiency, and operational reliability and versatility were obtained. The results indicate that the graphite electrode DC arc technology would be very well suited for treating high melting point wastes such as those found at INEL. The graphite electrode DC arc furnace has been demonstrated to be very simple, yet effective, with excellent prospects for remote or semi-remote operation

40 CFR 63.1651 - Definitions.

Science.gov (United States)

2010-07-01

... transfer by crane, truck, or other conveyance. Crushing and screening equipment means the crushers... resistive electrical power consumption of a submerged arc furnace, expressed as megawatts (MW). Malfunction... arc furnace means an electric submerged arc furnace that is equipped with a canopy hood above the...

A bench arc-furnace facility for fullerene and single-wall nanotubes synthesis

Directory of Open Access Journals (Sweden)

Huber John G

2001-01-01

Full Text Available A metallic-sample arc-furnace was modified to synthesize fullerenes and nanotubes. The (reversible changes and the process for producing single-wall nanotubes (SWNTs are described.

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.

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

International Nuclear Information System (INIS)

Wittle, J.K.; Hamilton, R.A.; Trescot, J.

1995-01-01

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

Maximizing the transferred power to electric arc furnace for having maximum production

International Nuclear Information System (INIS)

Samet, Haidar; Ghanbari, Teymoor; Ghaisari, Jafar

2014-01-01

In order to increase production of an EAF (electric arc furnace) by reduction of melting time, one can increase transferred power to the EAF. In other words a certain value of energy can be transferred to the EAF in less time. The transferred power to the EAF reduces when series reactors are utilized in order to have stable arc with desired characteristics. To compensate the reduced transferred power, the secondary voltage of the EAF transformer should be increased by tap changing of the transformer. On the other hand, after any tap changing of the EAF transformer, improved arc stability is degraded. Therefore, the series reactor and EAF transformer tap changing should be simultaneously determined to achieve arc with desired characteristics. In this research, three approaches are proposed to calculate the EAF system parameters, by which the optimal set-points of the different series reactor and EAF transformer taps are determined. The electric characteristics relevant to the EAF for the all transformer and series reactor taps with and without SVC (static VAr compensator) are plotted and based on these graphs the optimal set-points are tabulated. Finally, an economic evaluation is also presented for the methods. - Highlights: • The main goal is to transfer the maximum power to electric arc furnace. • Optimal transformer and series reactor taps are determined. • Arc stability and transferred power to EAF determine the optimal performance. • An economic assessment is done and the number of increased meltings is calculated

Calculation of gas release from DC and AC arc furnaces in a foundry

Science.gov (United States)

Krutyanskii, M. M.; Nekhamin, S. M.; Rebikov, E. M.

2016-12-01

A procedure for the calculation of gas release from arc furnaces is presented. The procedure is based on the stoichiometric ratios of the oxidation of carbon in liquid iron during the oxidation heat period and the oxidation of iron from a steel charge by oxygen in the period of solid charge melting during the gas exchange of the furnace cavity with the external atmosphere.

Optimizing of Work Arc Furnace to Decopperisation of Flash Slag

Directory of Open Access Journals (Sweden)

Bydałek A.W.

2015-09-01

Full Text Available Discusses an attempt to optimize the operation of an electric furnace slag to be decopperisation suspension of the internal recycling process for the production of copper. The paper presents a new method to recover copper from metallurgical slags in arc-resistance electric furnace. It involves the use of alternating current for a first period reduction, constant or pulsed DC in the final stage of processing. Even distribution of the electric field density in the final phase of melting caused to achieve an extremely low content of metallic copper in the slag phase. They achieved by including the economic effects by reducing the time reduction.

The electrical characteristics of copper slags in a 270 kVA DC arc furnace

International Nuclear Information System (INIS)

Derin, Bora; Sahin, Filiz Cinar; Yucel, Onuralp

2003-01-01

The electrical resistance of slags is the main criteria to determine the design and the operation conditions of slag resistance furnace (SRF) depending on temperature and composition. In this study, a 270 kVA DC electric arc furnace were used to determine the electrical characteristic of molten ancient copper slags. The specific conductivity of the slag was estimated by using furnace geometric factor given in the literature as an empirical formula and by using furnace resistance measured during smelting of the copper slag with or without different additives such as coke, CaO and Al 2 O 3 . (Original)

Submerged arc narrow gap welding of the steel DIN 20MnMoNi55

International Nuclear Information System (INIS)

Moraes, M.M.

1987-01-01

The methodology for submerged arc narrow gap welding for high thickness rolled steel DIN 20MnMoNi55 was developed, using din S3NiMo1 04 mm and 05 mm wires, and DIN 8B435 flux. For this purpose, submerged arc narrow gap welded joints with 50 mm and 120 mm thickness were made aiming the welding parameters optimization and the study of the influence of welding voltage, wire diameter and wire to groove face distance on the operational performance and on the welded joint quality, specially on the ISO-V impact toughness. These welded joints were checked by non-destructive mechanical and metallographic tests. Results were compared with those obtained by one 120 mm thickness submerged arc conventional gap welded joint, using the same base metal and consumables (05 mm wire). The analysis of the results shows that the increasing of the wire to groove face distance and the welding voltage increases the hardness and the ISO-V impact toughness of the weld metal. It shows that the reduction of the gap angle is the main cause for the obtained of a heat affected zone free from coarse grains, the reduction of the welding voltage, the increasing of the wire to groove face distance, and the grounding optimization also contribute for that. It was also concluded that the quality and the execution complexity level of a narrow gap welded joint are identical to a conventional gap welded joint. (author) [pt

Treatment studies of plutonium-bearing INEEL waste surrogates in a bench-scale arc furnace

International Nuclear Information System (INIS)

Freeman, C.J.

1997-05-01

Since 1989, the Subsurface Disposal Area (SDA) at the Idaho National Environmental and Engineering Laboratory (INEEL) has been included on the National Priority List for remediation. Arc- and plasma-heated furnaces are being considered for converting the radioactive mixed waste buried in the SDA to a stabilized-vitreous form. Nonradioactive, surrogate SDA wastes have been melted during tests in these types of furnaces, but data are needed on the behavior of transuranic (TRU) constituents, primarily plutonium, during thermal treatment. To begin collecting this data, plutonium-spiked SDA surrogates were processed in a bench-scale arc furnace to quantify the fate of the plutonium and other hazardous and nonhazardous metals. Test conditions included elevating the organic, lead, chloride, and sodium contents of the surrogates. Blends having higher organic contents caused furnace power levels to fluctuate. An organic content corresponding to 50% INEEL soil in a soil-waste blend was the highest achievable before power fluctuations made operating conditions unacceptable. The glass, metal, and off-gas solids produced from each surrogate blend tested were analyzed for elemental (including plutonium) content and the partitioning of each element to the corresponding phase was calculated

Treatment studies of plutonium-bearing INEEL waste surrogates in a bench-scale arc furnace

Energy Technology Data Exchange (ETDEWEB)

Freeman, C.J.

1997-05-01

Since 1989, the Subsurface Disposal Area (SDA) at the Idaho National Environmental and Engineering Laboratory (INEEL) has been included on the National Priority List for remediation. Arc- and plasma-heated furnaces are being considered for converting the radioactive mixed waste buried in the SDA to a stabilized-vitreous form. Nonradioactive, surrogate SDA wastes have been melted during tests in these types of furnaces, but data are needed on the behavior of transuranic (TRU) constituents, primarily plutonium, during thermal treatment. To begin collecting this data, plutonium-spiked SDA surrogates were processed in a bench-scale arc furnace to quantify the fate of the plutonium and other hazardous and nonhazardous metals. Test conditions included elevating the organic, lead, chloride, and sodium contents of the surrogates. Blends having higher organic contents caused furnace power levels to fluctuate. An organic content corresponding to 50% INEEL soil in a soil-waste blend was the highest achievable before power fluctuations made operating conditions unacceptable. The glass, metal, and off-gas solids produced from each surrogate blend tested were analyzed for elemental (including plutonium) content and the partitioning of each element to the corresponding phase was calculated.

Linearized Model of Electrical Arc Furnace Suitable for Analysis of Flicker Mitigation

Czech Academy of Sciences Publication Activity Database

Valouch, Viktor

2003-01-01

Roč. 48, č. 2 (2003), s. 147-156 ISSN 0001-7043 R&D Projects: GA AV ČR IAA2057301 Institutional research plan: CEZ:AV0Z2057903 Keywords : flicker * electrical arc furnace * unified power quality conditioner Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

In process acoustic emission in multirun submerged arc welding

International Nuclear Information System (INIS)

Asty, M.; Birac, C.

1980-01-01

In order to avoid the formation of deep grooves when repairing defects in welded joints in heavy plates, an investigation was made aiming to detect and locate the defects by in-process acoustic emission in multirun submerged arc welding. Twelve defects (lack of penetration, cracks, inclusions, lack of fusion together with inclusions, blowholes) were intentionally introduced when the first plate was welded. A space-time method for processing the acoustic activity during welding allowed the detection and the location of the intentional defects as well as of the most important accidental defects evidenced by ultrasonic testing [fr

A Heat and Mass Transfer Model of a Silicon Pilot Furnace

Science.gov (United States)

Sloman, Benjamin M.; Please, Colin P.; Van Gorder, Robert A.; Valderhaug, Aasgeir M.; Birkeland, Rolf G.; Wegge, Harald

2017-10-01

The most common technological route for metallurgical silicon production is to feed quartz and a carbon source ( e.g., coal, coke, or charcoal) into submerged-arc furnaces, which use electrodes as electrical conductors. We develop a mathematical model of a silicon furnace. A continuum approach is taken, and we derive from first principles the equations governing the time evolution of chemical concentrations, gas partial pressures, velocity, and temperature within a one-dimensional vertical section of a furnace. Numerical simulations are obtained for this model and are shown to compare favorably with experimental results obtained using silicon pilot furnaces. A rising interface is shown to exist at the base of the charge, with motion caused by the heating of the pilot furnace. We find that more reactive carbon reduces the silicon monoxide losses, while reducing the carbon content in the raw material mixture causes greater solid and liquid material to build-up in the charge region, indicative of crust formation (which can be detrimental to the silicon production process). We also comment on how the various findings could be relevant for industrial operations.

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.

Computational Fluid Dynamics (CFD) Investigation of Submerged Combustion Behavior in a Tuyere Blown Slag-fuming Furnace

Science.gov (United States)

Huda, Nazmul; Naser, Jamal; Brooks, G. A.; Reuter, M. A.; Matusewicz, R. W.

2012-10-01

A thin-slice computational fluid dynamics (CFD) model of a conventional tuyere blown slag-fuming furnace has been developed in Eulerian multiphase flow approach by employing a three-dimensional (3-D) hybrid unstructured orthographic grid system. The model considers a thin slice of the conventional tuyere blown slag-fuming furnace to investigate details of fluid flow, submerged coal combustion dynamics, coal use behavior, jet penetration behavior, bath interaction conditions, and generation of turbulence in the bath. The model was developed by coupling the CFD with the kinetics equations developed by Richards et al. for a zinc-fuming furnace. The model integrates submerged coal combustion at the tuyere tip and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with several user-defined subroutines in FORTRAN programming language were used to develop the model. The model predicted the velocity, temperature field of the molten slag bath, generated turbulence and vortex, and coal use behavior from the slag bath. The tuyere jet penetration length ( l P) was compared with the equation provided by Hoefele and Brimacombe from isothermal experimental work ( {{l_{{P}} }/{d_{o }} = 10.7( {N^' }_{Fr} } )^{0.46} ( {ρ_{{g}} /ρl } )^{0.35} } ) and found 2.26 times higher, which can be attributed to coal combustion and gas expansion at a high temperature. The jet expansion angle measured for the slag system studied is 85 deg for the specific inlet conditions during the simulation time studied. The highest coal penetration distance was found to be l/L = 0.2, where l is the distance from the tuyere tip along the center line and L is the total length (2.44 m) of the modeled furnace. The model also predicted that 10 pct of the injected coal bypasses the tuyere gas stream uncombusted and carried to the free surface by the tuyere gas stream, which

Single-walled nanohorns and other nanocarbons generated by submerged arc discharge between carbon electrodes in liquid argon and other media

International Nuclear Information System (INIS)

Vasu, K; Pramoda, K; Govindaraj, A; Rao, C N R; Moses, K

2014-01-01

Arc discharge between two graphite electrodes submerged in different liquid media yields various dimensional nanocarbon structures such as 1D carbon nanotubes and 2D graphene. Single-walled carbon nanohorns (SWNHs) prepared by submerged arc discharge in liquid nitrogen medium are found to have nitrogen impurities. Here, we report the structure and properties of pure and nitrogen-doped SWNHs obtained by submerged arc discharge in a liquid argon medium. The absence of an XPS N 1s signal, which is present in nanohorns obtained in liquid nitrogen, indicate that the nanohorns are free from nitrogen impurities. Raman spectra show a strong defect-induced D band and current–voltage characteristics show a slight nonlinear behavior. N 2 adsorption of pure SWNHs shows type-IV isotherms with a surface area of 300 m 2 g −1 . Adsorption of CO 2 and H 2 in pure SWNHs has also been measured. Arc discharge in other liquid media such as water, ethanol, dimethylformamide (DMF), n-methyl pyrrolidone (NMP), formamide, benzene, heptane and acetone yields different nanocarbon structures including multi-walled carbon nanotubes (MWNTs), few-layer graphene, carbon onions and carbon nanoparticles. (papers)

DC Electric Arc Furnace Application for Production of Nickel-Boron Master Alloys

Science.gov (United States)

Alkan, Murat; Tasyürek, Kerem Can; Bugdayci, Mehmet; Turan, Ahmet; Yücel, Onuralp

2017-09-01

In this study, nickel-boron (Ni-B) alloys were produced via a carbothermic reduction starting from boric acid (H3BO3) with high-purity nickel oxide (NiO), charcoal, and wood chips in a direct current arc furnace. In electric arc furnace experiments, different starting mixtures were used, and their effects on the chemical compositions of the final Ni-B alloys were investigated. After the reduction and melting stages, Ni-B alloys were obtained by tapping from the bottom of the furnace. The samples from the designated areas were also taken and analyzed. The chemical composition of the final alloys and selected samples were measured with wet chemical analysis. The Ni-B alloys had a composition of up to 14.82 mass% B. The phase contents of the final alloys and selected samples were measured using x-ray diffraction (XRD). The XRD data helped predict possible reactions and reaction mechanisms. The material and energy balance calculations were made via the XRD Rietveld and chemical compositions. Nickel boride phases started to form 600 mm below the surface. The targeted NiB phase was detected at the tapping zone of the crucible (850-900 mm depth). The energy consumption was 1.84-4.29 kWh/kg, and the electrode consumption was 10-12 g/kg of raw material charged.

Submerged-arc wire electrodes with nickel-plated surfaces

International Nuclear Information System (INIS)

Hagen, H. vom.

1976-01-01

The article reports on the development of SANWELD welding rods at GARHYTTAN's which is a wire free of impurities, copper, and hydrogen with a nickel surface. It is producted according to the SANBOND process. The wire has an optimum of mechanical quality grades depending on the powder used for welding, especially an improvement of notch impact strength. The elongation, especially the long-time values, are improved, hydrogen cracks are excluded depending on the correct powder or protective gas, and the low-temparature values are improved. An attendant phenomenon, which is not unimportant, is that the wires are practically corrosion-resistant in the non-welded state. The wire is suitable for submerged-arc welding in steam boilers and pressure vessels. (IHoe) [de

Chemical energy in electro arc furnace - examples from experience

International Nuclear Information System (INIS)

Shushlevski, Ljupcho; Georgievski, Panche; Hadzhidaovski, Ilija

2004-01-01

Great competition on the market in steel-producing and chemical lack of electrical energy leads to realization of new project in section Steelworks AD 'Makstil' - Skopje named: 'Substitution of electrical energy i.e. entering of additional chemical energy in Electrical arc furnace for steel melting using fuels-naturual gas (CH 4 ), oxygen (O 2 ) and carbon (C)'. It is accumulate experience from two and one half year of intensive use of chemical energy with its accompanying problems, appropriate efficiency and economy in process for steel producing. In 2001 year we announced and described project for using of an additional alternative chemical energy in aggregate Electrical are furnace. In this work we will present realization, working experience and efficiency of the system for generating chemical energy. Practical realization needs serious approach in chemical energy usage The usage of chemical energy brings restrictions and needs many innovation for protection of equipment from shown aggressiveness during the combustion of fuel gasses. (Author)

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.

Voltage Flicker Mitigation in Electric Arc Furnace using D-STATCOM

OpenAIRE

Deepthisree Madathil; Ilango Karuppasamy; Kirthika Devi V S; Manjula G Nair

2014-01-01

The major power quality issue of voltage flicker has resulted as a serious concern for the customers and heavy power companies. Voltage flicker is an impression of unsteadiness of visual sensation induced by a light source whose luminance fluctuates with time. This phenomenon is experienced when an Electric Arc Furnace (EAF) as load is connected to the power system. Flexible AC transmission devices (FACTS) devices were gradually utilized for voltage flicker reduction. In this paper the FACTS ...

Advances in submerged arc, narrow-gap welding with strip electrodes and thin, dual-wire electrodes

International Nuclear Information System (INIS)

Nies, H.

1990-01-01

Container and tank construction for nuclear installations traditionally is one of the major applications of narrow-gap welding with the submerged arc technique. This type of welding presents one problem, namely to completely and reliably remove the welding slag from the deep and narrow gap. The research report in hand explains the variants of welding techniques that have been tested and describes the results obtained, which primarily are reduced occurrence of faults, i.e. enhanced reliability, and better welding economy. As an alternative to welding with thick wire electrodes, which is the standard method for the applications under review, a new technique has been conceived and extensively tested, which uses thin strip electrodes at longitudinal position in the gap. This submerged arc, dual-wire technique with thin electrodes is characterised by a significantly higher thermal efficiency compared to welding with thick wires, so that the same energy input yields better efficiency of metal deposition. (orig./MM) [de

Recycling of electric arc furnace dust

International Nuclear Information System (INIS)

Marques Sobrinho, Vicente de Paulo Ferreira; Oliveira, Jose Roberto de; Tenorio, Jorge Alberto Soares; Espinosa, Denise Crocce Romano

2010-01-01

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)

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Diagnostic of the electrical characteristics to control the electric arc furnaces by a computer. Session 2. 2b N. 2. 2. 10

Energy Technology Data Exchange (ETDEWEB)

Hradilek, Z

1984-01-01

The article deals with a new method of diagnostic investigation into the instaneous electric power program of the electric arc furnace by use of thermoelectric converters. The electric magnitudes are recorded by a plotter and evaluated by a computer. The results obtained by this method are examined at the Vitkovice Steelworks/Czechoslovakia/ and can be applied to optimize the power program of an electric arc furnace by a control computer.

Smelting of high-quality boiler steel in large-load arc furnaces

Energy Technology Data Exchange (ETDEWEB)

Kablukovskij, A F; Breus, V M; Tyurin, E I; Khristich, V D; Dumchev, Ya P [Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR)

1975-02-01

High-grade steel can be obtained in large-capacity furnaces if the smelting technology used takes account of the size of the aggregates, the course of the metal fusion process, interaction with slag, furnace atmosphere, reducing agents, and other process characteristics. 12Kh1MF boiler steel smelted in a 100-ton electric arc furnace by an oxidizing process with oxygen bath blow and cast by the siphon method into 6.5-ton ingots using a slag-forming mixture (240 mm diameter billets and 219 to 245 mm diameter tubes) is satisfactory with regard to macro and microstructure, oxygen and nonmetallic oxide inclusion content, and mechanical properties. The stress rupture strength of 10/sup 5/ h at 570/sup 0/C is similar to that of open-hearth steel. Sulfides larger than a 3.5 spheroid have been detected in it. The nitrogen content of the electric steel is 0.0090 to 0.0120%, which is somewhat greater than usual in open-hearth metal. Of the oxygen inclusions in the steel, spinel-alumina predominates. Large inclusions were represented mainly by brittle silicates which appeared to be of exogenous origin.

Applicability of Carbonated Electric Arc Furnace Slag to Mortar

International Nuclear Information System (INIS)

Yokoyama, S; Izaki, M; Arisawa, R; Hisyamudin, M N N; Murakami, K; Maegawa, A

2012-01-01

Authors have been studying the absorption of CO 2 in the steelmaking slag. In this study, an application of the electric arc furnace slag after the carbonation to admixture of mortar was investigated with the JIS (A6206-1997) method for ground granulated blast-furnace slag for concrete. The percent flows for the test mortar were smaller than that for the standard mortar. The percent flow of the carbonated slag whose average particle size of more than approximately 4 μm increased with an increase in the average size of the particles. Because the compressive strengths of the test mortar cured for 91 days were almost the same as those cured 28 days, the slag after the carbonation was thought not to have self-hardening property for a medium and long term. The compressive strength for the test mortar was almost unchanged within a range of approximately 2 to 7 μm of the average particle size, and it in this range was highest. The activity indexes for the test mortar prepared with the slag after the carbonation ranged from approximately 40 to 60%.

Welding of Nb micro-alloyed steel by the submerged arc process using Brazilian consumables

International Nuclear Information System (INIS)

Scotti, A.; Quites, A.M.

1982-01-01

A set of procedures was established for welding of Nb micro-alloyed steel by the submerged arc process, using national consumables, in order to simultaneously achieve a more economic welding and better mechanical properties. From all the wire-flux combinations the better were the correspondent to AWS F84ED1, F74EM12K and F84EH14, the last being the best. (Author) [pt

Method and Mechanisms of Soil Stabilization Using Electric Arc Furnace Dust

OpenAIRE

Al-Amoudi, Omar S. Baghabra; Al-Homidy, Abdullah A.; Maslehuddin, Mohammed; Saleh, Tawfik A.

2017-01-01

This paper reports the method and mechanism for improving the strength of marl and desert sand utilizing electric arc furnace dust (EAFD), an industrial by-product, in lieu of cement or lime. EAFD was used in conjunction with a small quantity (2%) of cement. The mechanical properties and durability characteristics of marl and sand mixed with 2% cement plus 5-, 10-, 20- or 30%-EAFD, by weight of the soil, were evaluated. The soil-cement-EAFD mixtures were used to determine their unconfined com...

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.

Computational Fluid Dynamic Modeling of Zinc Slag Fuming Process in Top-Submerged Lance Smelting Furnace

Science.gov (United States)

Huda, Nazmul; Naser, Jamal; Brooks, Geoffrey; Reuter, Markus A.; Matusewicz, Robert W.

2012-02-01

Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian multiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the lance tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag-gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.

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

International Nuclear Information System (INIS)

Machado, Janaina G.M.S.; Brehm, Feliciane Andrade; Moraes, Carlos Alberto Mendes; Santos, Carlos Alberto dos; Vilela, Antonio Cezar Faria; Cunha, Joao Batista Marimon da

2006-01-01

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 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 Moessbauer 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 Moessbauer spectroscopy analysis

Production of small U Alx alloy buttons in a non consumable electrode arc furnace

International Nuclear Information System (INIS)

Koshimizu, S.; Lima, L.F.C.P. de; Leal Neto, R.M.

1994-01-01

Some results are presented, concerning with composition and phases, in small buttons of U Al x (10 to 50 g) produced in a non consumable electrode arc furnace. The uranium metal utilised is natural one produced in the IPEN. The convenience of the fabrication of small buttons of U AL x is discussed. (author). 3 refs, 2 figs, 1 tab

Characterization of electric arc furnace dust aiming reuse

International Nuclear Information System (INIS)

Grillo, F.F.; Oliveira, E.B.G.; Oliveira, J.R. de; Telles, V.B.; Tenorio, J.A.S.

2010-01-01

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 μm). The XRD has presented compounds such as ZnFe 2 O 4 , Fe 3 O 4 , ZnO e SiO 2 . This work showed that its possible recovery approximately 92% of metal iron from dust generated during steelmaking.This (author)

Operation of arc heating furnace on manufacturing gigantic ingots and segregation of gigantic ingots

International Nuclear Information System (INIS)

Niimi, Takayasu; Okamura, Masayoshi

1976-01-01

The techniques and procedure for manufacturing gigantic ingots heavier than 200 t are described. Especially, practical results of an arc heating furnace which plays an important role in the procedure and segregation of gigantic ingots are discussed in detail. By appropriate operations of the arc heating furnance, hydrogen and phosphorus are kept unchanged, and oxygen and sulphur decrease to very low levels. Furthermore, the temperature can be accurately controlled. The application of multipour technique reduces segregation and its degree is dependent on kinds of steel. V-segregation and inverted V-segregation in steel deoxidized with carbon in vacuum seem to be very slight. (auth.)

Heat-electrical regeneration way to intensive energy saving in an electric arc furnaces

Science.gov (United States)

Kartavtcev, S.; Matveev, S.; Neshporenko, E.

2018-03-01

Energy saving in steel production is of great significance for its large economical scale of 1500 mil t/year and high-energy consumption. Steady trend of last years is an increase of steel production in electric arc furnaces (EAF) with a very high consumption of electricity up to 750 kWh/ton. The intention to reduce so much energy consumption they can reach by many ways. One of such way is a transforming heat energy of liquid steel to electricity and destine it to steel electric arc process. Under certain conditions, it may lead to “zero” consumption of electric power in the process. The development of these conditions leads to the formation of energy-efficient heat schemes, with a minimum electricity consumption from the external network.

Stainless steel submerged arc weld fusion line toughness

International Nuclear Information System (INIS)

Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M.

1995-04-01

This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations

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.

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.

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.

Study on mechanical and microstructure behavior of submerged arc welding flux using red mud

Science.gov (United States)

Dewangan, Rishi; Pandey, Pankaj K.; Upadhyay, Renu

2018-05-01

This paper emphasis on utilization of Red Mud for preparing submerged arc welding flux and study its mechanical and microstructure behavior. Among the six fluxes prepared in the laboratory, Flux no. 1 (basicity 1.106) found to be best due to its running performance, micro hardness and Brinell hardness. The hardness value (HV) of the fluxes was varying from 165.70 to 217.15 at a load of 1000gm respectively. From the micrograph of welded metal, acicular ferrite found to be optimum which helps in increasing the ductility and hardness of the welded material.

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

International Nuclear Information System (INIS)

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

2015-01-01

Highlights: • EAF dust was characterized with particle size analysis, XRF, and EPMA. • Slag particles showed no sign of reaction with Zn vapor. • Fe 2 O 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 2 O 3 , Zn vapor reacts to form ZnFe 2 O 4 and ZnO. - Abstract: To better understand the phenomena of ZnFe 2 O 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 2 O 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 2 O 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 2 O 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

The effect of flux on properties of weld in submerged arc welding with filler metal

International Nuclear Information System (INIS)

Fattahpour, Iran.

1984-01-01

In the submerged-arc welding, the electrode wire is shielded by a blanket of granular fusible material called a flux. This granular material, flux, must ensure the deposition of weld metal of given chemical composition and specified mechanical properties. The flux must also ensure stable burning of the welding arc and contribute to the formation of a dense weld of required shape and size, and free from pores, cracks and slag inclusions. As the deposited molten metal solidifies, the flux must form a slag crust, easily separable from the surface of the weld. This material must be of a certain chemical composition and possess definite physical properties, such as melting point, viscosity, bulk weight. The chemical composition of the flux is chosen, depending on the composition of the welded metal and electrode wire used. (Author)

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

OpenAIRE

C. L. Beh; Luqman Chuah; Thomas S.Y. Choong; Mohd. Z.B. Kamarudzaman; Khalina Abdan

2010-01-01

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 k...

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

International Nuclear Information System (INIS)

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

2007-01-01

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

The modelling of irradiation embrittlement in submerged-arc welds

International Nuclear Information System (INIS)

Bolton, C.J.; Buswell, J.T.; Jones, R.B.; Moskovic, R.; Priest, R.H.

1996-01-01

Until very recently, the irradiation embrittlement behavior of submerged-arc welds has been interpreted in terms of two mechanisms, namely a matrix damage component and an additional component due to the irradiation-enhanced production of copper-rich precipitates. However, some of the weld specimens from a recent accelerated re-irradiation experiment have shown high Charpy shifts which exceeded the values expected from the measured shift in yield stress. Microstructural examination has revealed the occurrence of intergranular fracture (IGF) in these specimens, accompanied by grain boundary segregation of phosphorus. Theoretical models were developed to predict the parametric dependence of irradiation-enhanced phosphorus segregation on experimental variables. Using these parametric forms, along with the concept of a critical level of segregation for the onset of IGF instead of cleavage, a three mechanism trend curve has been developed. The form of this trend curve, taking into account IGF as well as matrix and copper embrittlement, is thus mechanistically based. The constants in the equation, however, are obtained by a statistical fit to the actual Charpy shift database

Nuclear Technology. Course 28: Welding Inspection. Module 28-3, Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Submerged Arc Welding.

Science.gov (United States)

Espy, John

This third in a series of ten modules for a course titled Welding Inspection presents the apparatus, process techniques, procedures, applications, associated defects, and inspection for the tungsten inert gas, metal inert gas, and submerged arc welding processes. The module follows a typical format that includes the following sections: (1)…

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

International Nuclear Information System (INIS)

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. (plasma technology)

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

Science.gov (United States)

Chen, Mingzhou; Meng, Yuedong; Shi, Jiabiao; Ni, Guohua; Jiang, Yiman; Yu, Xinyao; ZHAO, Peng

2009-10-01

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.

Fatigue crack growth behavior of pressure vessel steels and submerged arc weldments in a high-temperature pressurized water environment

International Nuclear Information System (INIS)

Liaw, P.K.; Logsdon, W.A.; Begley, J.A.

1989-01-01

The fatigue crack growth rate (FCGR) properties of SA508 Cl 2a and SA533 Gr A Cl 2 pressure vessel steels and the corresponding automatic submerged arc weldments were developed in a high-temperature pressurized water (HPW) environment at 288 degrees C (550 degrees F) and 7.2 MPa (1044 psi) at load ratios of 0.20 and 0.50. The properties were generally conservative compared to American Society of Mechanical Engineers Section XI water environment reference curve. The growth rate of fatigue cracks in the base materials, however, was faster in the HPW environment than in a 288 degrees C (550 degrees F) base line air environment. The growth rate of fatigue cracks in the two submerged arc weldments was also accelerated in the HPW environment but to a lesser degree than that demonstrated by the base materials. In the air environment, fatigue striations were observed, independent of material and load ratio, while in the HPW environment, some intergranular facets were present. The greater environmental effect on crack growth rates displayed by the base materials compared the weldments attributed to a different sulfide composition and morphology

Interactive Relationship between Silver Ions and Silver Nanoparticles with PVA Prepared by the Submerged Arc Discharge Method

Directory of Open Access Journals (Sweden)

Kuo-Hsiung Tseng

2018-01-01

Full Text Available This study uses the submerged arc discharge method (SADM and the concentrated energy of arc to melt silver metal in deionized water (DW so as to prepare metal fluid with nanoparticles and submicron particles. The process is free from any chemical agent; it is rapid and simple, and rapid and mass production is available (0.5 L/min. Aside from the silver nanoparticle (Ag0, silver ions (Ag+ exist in the colloidal Ag prepared by the system. In the preparation of colloidal Ag, polyvinyl alcohol (PVA is used as an additive so that the Ag0/Ag+ concentration, arcing rate, peak, and scanning electron microscopic (SEM images in the cases with and without PVA can be analyzed. The findings show that the Ag0/Ag+ concentration increases with the addition level of PVA, while the nano-Ag and Ag+ electrode arcing rate rises. The UV-Vis absorption peak increases Ag0 absorbance and shifts as the dispersity increases with PVA addition. Lastly, with PVA addition, the proposed method can prepare smaller and more amounts of Ag0 nanoparticles, distributed uniformly. PVA possesses many distinct features such as cladding, dispersion, and stability.

Nickel recovery from electric arc furnace slag by magnetic separation

Directory of Open Access Journals (Sweden)

Sakaroglou Marianna

2017-01-01

Full Text Available During the pyrometallurgical treatment of the nickel-bearing laterite in the plant of G.M.M. S.A. LARCO, slag is produced after treatment in electric-arc furnace (EAF that contains 0.10 to 0.20 % Ni. Taking into account the great quantity of slag produced per year, the recovery of nickel from the EAF slag will add benefits to the entire process. The target of the current work is to investigate the possibility of nickel recovery from EAF slag by magnetic separation. To meet the target, the effect of the following parameters was studied: grain size, magnetic field intensity, thickness of slag layer, moisture content, and re-grinding of the coarser slag particles. The results show that it is possible to obtain a magnetic product with nickel grade close to that of the primary raw material or even better, with sufficient nickel recovery.

DEVELOPMENT OF SOFTWARE “PRODSP-1.0” FOR OPTIMIZATION OF THE DEPHOSPHORIZATION PROCESSES IN ARC STEEL-FURNACES FOR TECHNOLOGICAL LINE-UP OF RUP “BMZ”

Directory of Open Access Journals (Sweden)

A. A. Chichko

2006-01-01

Full Text Available The software “ProDSP-1,0” allowing to forecast the dynamics of the dephosphorizaiton process at casting course in arc steel-furnace, is worked out. The examples of working of different program operating regimes, showing the possibilities of phosphorus control in steel-furnace of RUP ‘'BMZ'' are given.

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.

Mathematical model for optimization of multilayer submerged-arc welding of frame equipment of power units

International Nuclear Information System (INIS)

Pankov, V.V.; Chernyshev, G.G.; Kozlov, N.E.

1987-01-01

A mathematical model for optimization of multilayer submerged arc welding of frame equipment of power units is constructed. The variation-energy method permits to construct the universal mathematical model for strengthening formation of a single bead; the method is reasonable for simulation of a multilayer welded joint. Minimization of the distance between maximum and minimum layer height of a built-up metal is the necessary condition for qualitative formation of the multilayer joint. One can calculate in real time scale the optimal vector of maximally ten parameters under the multilayer welding condition immediately after change in the grooving width using the developed mathematical model of optimization

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

Recycling of rubber tires in electric arc furnace steelmaking: simultaneous combustion of metallurgical coke and rubber tyres blends

Energy Technology Data Exchange (ETDEWEB)

Magdalena Zaharia; Veena Sahajwalla; Byong-Chul Kim; Rita Khanna; N. Saha-Chaudhury; Paul O' Kane; Jonathan Dicker; Catherine Skidmore; David Knights [University of New South Wales, Sydney, NSW (Australia). School of Materials Science and Engineering

2009-05-15

The present study investigates the effect of addition of waste rubber tires on the combustion behavior of its blends with coke for carbon injection in electric arc furnace steelmaking. Waste rubber tires were mixed in different proportions with metallurgical coke (MC) (10:90, 20:80, 30:70) for combustion and pyrolysis at 1473 K in a drop tube furnace (DTF) and thermogravimetric analyzer (TGA), respectively. Under experimental conditions most of the rubber blends indicated higher combustion efficiencies compared to those of the constituent coke. In the early stage of combustion the weight loss rate of the blends is much faster compared to that of the raw coke due to the higher volatile yield of rubber. The presence of rubber in the blends may have had an impact upon the structure during the release and combustion of their high volatile matter (VM) and hence increased char burnout. Measurements of micropore surface area and bulk density of the chars collected after combustion support the higher combustion efficiency of the blends in comparison to coke alone. The surface morphology of the 30% rubber blend revealed pores in the residual char that might be attributed to volatile evolution during high temperature reaction in oxygen atmosphere. Physical properties and VM appear to have a major effect upon the measured combustion efficiency of rubber blends. The study demonstrates that waste rubber tires can be successfully co-injected with metallurgical coke in electric arc furnace steelmaking process to provide additional energy from combustion. 44 refs., 11 figs., 2 tabs.

A combined arc-melting and tilt-casting furnace for the manufacture of high-purity bulk metallic glass materials.

Science.gov (United States)

Soinila, E; Pihlajamäki, T; Bossuyt, S; Hänninen, H

2011-07-01

An arc-melting furnace which includes a tilt-casting facility was designed and built, for the purpose of producing bulk metallic glass specimens. Tilt-casting was chosen because reportedly, in combination with high-purity processing, it produces the best fatigue endurance in Zr-based bulk metallic glasses. Incorporating the alloying and casting facilities in a single piece of equipment reduces the amount of laboratory space and capital investment needed. Eliminating the sample transfer step from the production process also saves time and reduces sample contamination. This is important because the glass forming ability in many alloy systems, such as Zr-based glass-forming alloys, deteriorates rapidly with increasing oxygen content of the specimen. The challenge was to create a versatile instrument, in which high purity conditions can be maintained throughout the process, even when melting alloys with high affinity for oxygen. Therefore, the design provides a high-vacuum chamber to be filled with a low-oxygen inert atmosphere, and takes special care to keep the system hermetically sealed throughout the process. In particular, movements of the arc-melting electrode and sample manipulator arm are accommodated by deformable metal bellows, rather than sliding O-ring seals, and the whole furnace is tilted for tilt-casting. This performance of the furnace is demonstrated by alloying and casting Zr(55)Cu(30)Al(10)Ni(5) directly into rods up to ø 10 mm which are verified to be amorphous by x-ray diffraction and differential scanning calorimetry, and to exhibit locally ductile fracture at liquid nitrogen temperature.

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.

Improved Casting Furnace Conceptual Design

Energy Technology Data Exchange (ETDEWEB)

Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tolman, David Donald [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2017-02-01

In an attempt to ensure more consistent casting results and remove some schedule variance associated with casting, an improved casting furnace concept has been developed. The improved furnace uses the existing arc melter hardware and glovebox utilities. The furnace concept was designed around physical and operational requirements such as; a charge sized of less than 30 grams, high heating rates and minimal additional footprint. The conceptual model is shown in the report as well as a summary of how the requirements were met.

High temperature aircraft research furnace facilities

Science.gov (United States)

Smith, James E., Jr.; Cashon, John L.

1992-01-01

Focus is on the design, fabrication, and development of the High Temperature Aircraft Research Furnace Facilities (HTARFF). The HTARFF was developed to process electrically conductive materials with high melting points in a low gravity environment. The basic principle of operation is to accurately translate a high temperature arc-plasma gas front as it orbits around a cylindrical sample, thereby making it possible to precisely traverse the entire surface of a sample. The furnace utilizes the gas-tungsten-arc-welding (GTAW) process, also commonly referred to as Tungsten-Inert-Gas (TIG). The HTARFF was developed to further research efforts in the areas of directional solidification, float-zone processing, welding in a low-gravity environment, and segregation effects in metals. The furnace is intended for use aboard the NASA-JSC Reduced Gravity Program KC-135A Aircraft.

Upper shelf toughness of six submerged-arc weldmetals manufactured using Linde 124 flux

International Nuclear Information System (INIS)

Druce, S.G.; Hippsley, C.A.

1984-06-01

This paper describes the testing technique, data analysis procedures and results from the first phase of an experimental programme investigating upper shelf toughness of six submerged-arc weldmetals. The welds were manufactured using uncoated, Nickel coated and Copper coated wire electrodes and Linde 124 flux. J integral crack growth resistance curves have been derived from tests on single specimens over a range in temperature from 150 to 290 deg C. The results indicate a general decline in toughness with increasing temperature. At 290 deg C, the levels of initiation toughness from all six welds were essentially constant varying between 152 to 159 MPa square root of m. The Jsub(I)-R curves derived from this work are compared with toughness data used in the Marshall Study Group report of an assessment of the integrity of PWR pressure vessels. (author)

Monitoring of the submerged arc welding process using current and voltage transducers

International Nuclear Information System (INIS)

Barrera, G.; Velez, M.; Espinosa, M.A.; Santos, O.; Barrera, E.; Gomez, G.

1996-01-01

Welding by fusion is one of the most used techniques to join materials in the manufacture industry. given the increase in applications of this welding process and the demand of more quality in the welding deposits, these welding processes are good candidates for the improvement of their instrumentation and control. Any improvement in the control technique will have a positive effect in the quality and productivity of the welding process. Some of the most significant variables in the submerged arc welding process are: current, voltage and torch speed. For the instrumentation of this research work, two transducers were designed, one for CD current monitoring and one for CD voltage monitoring of the welding machine. The design of both transducers includes an isolation amplifier. Graphical programming and the concept of virtual instrumentation were the main tools used for the design of the data acquisition system and the signal processing task. (Author) 9 refs

Industrial study of iron oxide reduction by injection of carbon particles into the electric arc furnace

International Nuclear Information System (INIS)

Conejo, A. N.; Torres, R.; Cuellar, E.

1999-01-01

An industrial study was conducted in electric arc furnaces (EAF) employing 100% direct reduced iron to evaluate the oxidation level of the slag-metal system. Energy consumption is decreased by injecting gaseous oxygen, however, slag oxidation also increases. In order to reduce the extent of oxidation while keeping a high volume of the oxygen injected , it is required: a) to optimize the carbon injection practice, b) to increase the carbon concentration of sponge iron, c) to operate with soluble carbon in both the metal and the slag beyond a critical level and d) to employ a low temperature profile, on average 1,650 degree centigrade. A method to define the proper amount of carbon in sponge iron which considers their metallization as well as the amount of oxygen injected is proposed. The position of the lance is critical in order to optimize the practice of carbon injection and assure a better residence time of the carbon particles within the furnace. (Author) 23 refs

The modelling of irradiation-enhanced phosphorus segregation in neutron irradiated reactor pressure vessel submerged-arc welds

Energy Technology Data Exchange (ETDEWEB)

Druce, S.G.; English, C.A.; Foreman, A.J.E.; McElroy, R.J.; Vatter, I.A. [AEA Technology, Didcot (United Kingdom). Harwell Lab.; Bolton, C.J.; Buswell, J.T.; Jones, R.B. [Nuclear Electric, Berkeley (United Kingdom). Berkeley Technology Centre

1996-12-31

Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such ad dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies. The critical parameters in the models have been adjusted to give consistency with the available reference data, and predictions have been made of the dependence of segregation on a number of variables.

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)

Method and Mechanisms of Soil Stabilization Using Electric Arc Furnace Dust

Science.gov (United States)

Al-Amoudi, Omar S. Baghabra; Al-Homidy, Abdullah A.; Maslehuddin, Mohammed; Saleh, Tawfik A.

2017-04-01

This paper reports the method and mechanism for improving the strength of marl and desert sand utilizing electric arc furnace dust (EAFD), an industrial by-product, in lieu of cement or lime. EAFD was used in conjunction with a small quantity (2%) of cement. The mechanical properties and durability characteristics of marl and sand mixed with 2% cement plus 5-, 10-, 20- or 30%-EAFD, by weight of the soil, were evaluated. The soil-cement-EAFD mixtures were used to determine their unconfined compressive strength (UCS), soaked California Bearing Ratio (CBR) and durability. The risk of leaching of toxic heavy metals, such as lead and cadmium, from the stabilized soils to the groundwater was also investigated. The mechanisms of stabilization of the selected soils due to the use of EAFD along with a small quantity of cement are also elucidated. The usage of 20 to 30% EAFD with 2% cement was noted to considerably improve the mechanical properties and durability of both marl and sand.

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.

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.

Welding by submerged arc of steel with addition of iron powder; Soldagem por arco submerso de aco microligado com adicao de po de ferro

Energy Technology Data Exchange (ETDEWEB)

Gomes, Samuel I.N.; Spinelli, Dirceu [Sao Paulo Univ., Sao Carlos, SP (Brazil). Escola de Engenharia; Souza, Paulo C.R. D. de [SICOM Compressores Ltda., Sao Carlos, SP (Brazil); Magalhaes Bento Goncalves, Gilberto de [Bauru Univ., SP (Brazil)

1993-12-31

Welding metals with and without iron powder addition were produced in steel plates ASTM A 242 by submerged arc process. as a conclusion, the mechanical properties of hardness and toughness of weld metal and heat affect zone were more affected when the welding were done with lower heat input. (author). 16 refs., 3 figs., 9 tabs.

[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.

Optimization of submerged arc welding process parameters using quasi-oppositional based Jaya algorithm

International Nuclear Information System (INIS)

Rao, R. Venkata; Rai, Dhiraj P.

2017-01-01

Submerged arc welding (SAW) is characterized as a multi-input process. Selection of optimum combination of process parameters of SAW process is a vital task in order to achieve high quality of weld and productivity. The objective of this work is to optimize the SAW process parameters using a simple optimization algorithm, which is fast, robust and convenient. Therefore, in this work a very recently proposed optimization algorithm named Jaya algorithm is applied to solve the optimization problems in SAW process. In addition, a modified version of Jaya algorithm with oppositional based learning, named “Quasi-oppositional based Jaya algorithm” (QO-Jaya) is proposed in order to improve the performance of the Jaya algorithm. Three optimization case studies are considered and the results obtained by Jaya algorithm and QO-Jaya algorithm are compared with the results obtained by well-known optimization algorithms such as Genetic algorithm (GA), Particle swarm optimization (PSO), Imperialist competitive algorithm (ICA) and Teaching learning based optimization (TLBO).

Optimization of submerged arc welding process parameters using quasi-oppositional based Jaya algorithm

Energy Technology Data Exchange (ETDEWEB)

Rao, R. Venkata; Rai, Dhiraj P. [Sardar Vallabhbhai National Institute of Technology, Gujarat (India)

2017-05-15

Submerged arc welding (SAW) is characterized as a multi-input process. Selection of optimum combination of process parameters of SAW process is a vital task in order to achieve high quality of weld and productivity. The objective of this work is to optimize the SAW process parameters using a simple optimization algorithm, which is fast, robust and convenient. Therefore, in this work a very recently proposed optimization algorithm named Jaya algorithm is applied to solve the optimization problems in SAW process. In addition, a modified version of Jaya algorithm with oppositional based learning, named “Quasi-oppositional based Jaya algorithm” (QO-Jaya) is proposed in order to improve the performance of the Jaya algorithm. Three optimization case studies are considered and the results obtained by Jaya algorithm and QO-Jaya algorithm are compared with the results obtained by well-known optimization algorithms such as Genetic algorithm (GA), Particle swarm optimization (PSO), Imperialist competitive algorithm (ICA) and Teaching learning based optimization (TLBO).

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.

Addition of electric arc furnace dust in hot metal changing the form of addition

International Nuclear Information System (INIS)

Marques Sobrinho, Vicente de Paulo Ferreira; Oliveira, Jose Roberto de; Vieira, Estefano Aparecido; Telles, Victor Bridi; Grillo, Felipe Fardin; Tenorio, Jorge Alberto Soares; Espinosa, Denise Crocce Romano

2014-01-01

This research aims to study the incorporation of the mass of electric arc furnace dust (EAFD), by addition in hot metal (1.78% Si) at a temperature of 1,400 degrees Celsius. The EAFD is from a steel plant producing long steel. The addition of the EAFD was as received, in the form of briquettes without agitation of the hot metal and in the form of briquettes with agitation of the hot metal. Previously, the EAFD was characterized using the following techniques: chemical analysis, size analysis, X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The achievement of fusion experiments in laboratory scale, took place in a vertical tubular furnace with temperature control. The fusion experiments to assess the incorporation of EAFD mass used graphite crucibles. After cooling, the hot metal and the slag, remaining in the crucible, were weighed to do a mass balance. A flow of inert gas (argon) was maintained inside the furnace during the experiments. Results show that the experiment with addition of EAFD as received presents the best result of incorporating the mass of the final hot metal (1.73%) combined with the lowest percentage of volatilized mass of EAFD (46.52%). The experiment addition of EAFD in the form of briquette with agitation of hot metal presents the lowest percentage of slag mass (4.58%). The zinc content of volatilized EAFD (64.30%) is higher than the zinc content of the imported ore concentrate (52%) and zinc content of the national ore concentrate (12% to 39%). The presence of lead and cadmium in the slag characterizing it as a hazardous solid waste. (author)

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.

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)

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

Research On Technology Of Making Rare Earth Alloy Having Rare Earth Content ≽30% From Ore (≽40% REO) Using Aluminum Thermal Technology In Arc Furnace

International Nuclear Information System (INIS)

Ngo Xuan Hung; Ngo Trong Hiep; Tran Duy Hai; Nguyen Huu Phuc

2014-01-01

Arc furnace was used to smelt materials consisting of rare earth ore having rare earth content of ≽40% REO, aluminum as the reducing agent and additives. Rare earth alloy was obtained with rare earth metal content of more than 30%. (author)

Graphite electrode dc arc technology development for treatment of buried wastes

International Nuclear Information System (INIS)

Surma, J.E.; Cohn, D.R.; Smatlak, D.L.; Thomas, P.; Woskov, P.P.

1993-02-01

A ''National Laboratory-University-Industrial'' three-way partnership has been established between the Pacific Northwest Laboratory (PNL), Massachusetts Institute of Technology (MIT), and Electro-Pyrolysis, Inc. (EPI) to develop graphite electrode DC arc technology for the treatment of buried wastes. This paper outlines the PNL-MIT-EPI program describing a series of engineering-scale DC arc furnace tests conducted in an EPI furnace at the Plasma Fusion Center at MIT, and a description of the second phase of this program involving the design, fabrication, and testing of a pilot-scale DC arc furnace. Included in this work is the development and implementation of diagnostics to evaluate and optimize high temperature thermal processes such as the DC arc technology

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.

40 CFR 60.265 - Monitoring of operations.

Science.gov (United States)

2010-07-01

... Production Facilities § 60.265 Monitoring of operations. (a) The owner or operator of any electric submerged... side of the transformer. The device must have an accuracy of ±5 percent over its operating range. (c... owner or operator of an electric submerged arc furnace that is equipped with a water cooled cover which...

Recycling of Manganese Secondary Raw Material Via Cold-Bond Pelletizing Process

International Nuclear Information System (INIS)

Ahmed, Y.M.Z.; Mohamed, F.M.

2004-01-01

Large quantities of fines were produced during the shipping, transportation, handling and storage of manganese ore sinter imported from different countries to Sinai Company for ferromanganese production. These fines are generally considered as valuable secondary raw materials. Hence, they have a potential to be recycled back to the submerged arc furnace after having been agglomerated. For agglomerates to be considered as feed materials for submerged arc furnace they must have sufficient room temperature strength. Cold-bonded penalization process offers an economically attractive and environmentally viable method for achieving this. Ordinary Portland cement was used in this investigation for the purpose of producing a suitable cold-bonded pellet from such fines. In this investigation, the effect of adding different percentages of Portland cement on the mechanical properties of both green and pellet dried at room temperature for 1, 3, 7, 14, and 28 days of normal curing were studied. The results revealed that, although the compressive strength of green pellets improved with the increase of the amount of cement added. retardation in pellet drop strength was reported. Whereas, the increase in both the cement content and time of drying leads to increase in the mechanical properties of pellets normally cured at room temperature. pellets obtain with the addition of 9% cement shows reasonable mechanical properties to be charged in the submerged are furnace. ferromanganese alloy having a standard range composition was produced in a laboratory submerged are furnace using such pellets

Preparation of concrete mixtures with electric arc furnace slag and recycled ground glass

Science.gov (United States)

Pérez Rojas, Y.; López, E. Vera; López Rodríguez, M.; Díaz Pita, J.

2017-12-01

The present work includes the first advances in the development of investigations that seek to include Ground Grinding Glass (GRR) and the Electric Arc Furnace Slag (EAFS) in the production of mixtures of hydraulic concrete mixing them simultaneously, so that it satisfies the specifications techniques to be used in the construction of rigid pavements. Firstly, we cite the tests carried out on the different materials to obtain their physical, chemical and mechanical characterization and determine their compliance, as well as the measurement of certain characteristics that may be somewhat empirical to standardize their control. Technique such as X-Ray Diffraction (XRD), X-ray Fluorescence Spectrometry (XFR) and Scanning Electron Microscopy (SEM) have been used. Once the results of the characterization tests and their correspondence with the Colombian technical standards have been obtained, it has become possible to select the use of the Transparent Recycled Ground Glass (TRGG) as the most suitable for the replacement of the sand in the dosage of new mixtures modified concrete.

Use of pulsed arc welding for butt joint fabrication

International Nuclear Information System (INIS)

Merkulov, B.A.

1977-01-01

A technology of pulsed-arc butt welding with periodic wire feed to the welding zone has been developed. The pulsed arc is suitable both for submerged and gas-shielded weldings. The technology proposed has some advantages over the stationary-arc welding. Control of the amplitude-frequency characteristics of the process enables one to affect melting and crystallization conditions of the welding crater, weld shape, relation between melting and deposited metal section areas, etc., as well as to reduce heat contribution to the base metal. The new process is shown to be applicable in power engineering. Automatic submerged welding conditions are given for low-carbon and pearlitic heat-resistant steels

Simultaneous obtention of multicomponent ferroalloy and slag from black sands for the development of electrical arc welding consumables

International Nuclear Information System (INIS)

Cruz-Crespo, A.; Gomez-Rodriguez, L.; Garcia-Sanchez, L. L.; Quintana-Puchol, R.; Cerpa-Naranjo, A.; Cores-Sanchez, A.

2004-01-01

In this paper, chemical and mineralogical characterizations of the black sands of the Mejias placer of Sagua de Tanamo (the most important beach littoral placer of the northwest of oriental Cuba) are exposed. Starting from these characterizations a calculation strategy is developed for the making of the metallurgical load that allows to obtain simultaneously, when processed by carbothermic reduction in an electrical arc furnace, a multicomponent ferroalloy and a useful slag for the making of electric arch welding consumables. The powder of the obtained slag is agglomerated with liquid glass. The resulting pellets, due to their behavior on the submerged arc welding (SAW) present technological and metallurgical properties that correspond with the requirements of an agglomerated flux matrix. The chemical composition of the multicomponent ferroalloy is constituted by metallic elements of high metallurgical and alloyed values (V, Cr, Mo, Ti, Nb). It is appropriate for the formulation of consumables for manual welding (SMAW) and SAW, as well. (Author) 15 refs

Computer-integrated electric-arc melting process control system

OpenAIRE

Дёмин, Дмитрий Александрович

2014-01-01

Developing common principles of completing melting process automation systems with hardware and creating on their basis rational choices of computer- integrated electricarc melting control systems is an actual task since it allows a comprehensive approach to the issue of modernizing melting sites of workshops. This approach allows to form the computer-integrated electric-arc furnace control system as part of a queuing system “electric-arc furnace - foundry conveyor” and consider, when taking ...

Graphite electrode DC arc technology program for buried waste treatment

International Nuclear Information System (INIS)

Wittle, J.K.; Hamilton, R.A.; Cohn, D.R.; Woskov, P.P.; Thomas, P.; Surma, J.E.; Titus, C.H.

1994-01-01

The goal of the program is to apply EPI's Arc Furnace to the processing of Subsurface Disposal Area (SDA) waste from Idaho National Engineering Laboratory. This is being facilitated through the Department of Energy's Buried Waste Integrated Demonstration (BWID) program. A second objective is to apply the diagnostics capability of MIT's Plasma Fusion Center to the understanding of the high temperature processes taking place in the furnace. This diagnostics technology has promise for being applicable in other thermal treatment processes. The program has two parts, a test series in an engineering-scale DC arc furnace which was conducted in an EPI furnace installed at the Plasma Fusion Center and a pilot-scale unit which is under construction at MIT. This pilot-scale furnace will be capable of operating in a continuous feed and continuous tap mode. Included in this work is the development and implementation of diagnostics to evaluate high temperature processes such as DC arc technology. This technology can be used as an effective stabilization process for Superfund wastes

The application of imperialist competitive algorithm for optimization of deposition rate in submerged arc welding process using TiO2 nano particle

International Nuclear Information System (INIS)

Ghaderi, Mohammad Reza; Eslampanah, Amirhossein; Ghaderi, Kianoosh; Aghakhani, Masood

2015-01-01

We used a novel optimization algorithm based on the imperialist competitive algorithm (ICA) to optimize the deposition rate in the submerged arc welding (SAW) process. This algorithm offers some advantages such as simplicity, accuracy and time saving. Experiments were conducted based on a five factor, five level rotatable central composite design (RCCD) to collect welding data for deposition rate as a function of welding current, arc voltage, contact tip to plate distance, welding speed and thickness of TiO 2 nanoparticles coated on the plates of mild steel. Furthermore, regression equation for deposition rate was obtained using least squares method. The regression equation as the cost function was optimized using ICA. Ultimately, the levels of input variables to achieve maximum deposition rate were obtained using ICA. Computational results indicate that the proposed algorithm is quite effective and powerful in optimizing the cost function.

STUDY OF THE INFLUENCE OF THE HEAT INPUT ON MECHANICAL PROPERTIES OF C-Mn STEEL WELD METALS OBTAINED BY SUBMERGED ARC PROCESS

Directory of Open Access Journals (Sweden)

Erick de Sousa Marouço

2013-06-01

Full Text Available The present work is part of a research program that aims to evaluate the technical feasibility of increasing productivity in the manufacturing of tubular components for offshore oil industry, which are fully welded by automatic submerged arc welding process, with high heat input, but with no impairment on the impact toughness of the weld metal. Multipass welds were produced by the submerged arc welding process, with a combination of F7A4-EM12K (wire/flux, by using a 3.2 mm-diameter wire, preheating at 80°C, with direct current, in flat position, with heat input varying from 3.5 kJ/mm to 12 kJ/mm. After welding, tensile tests and Charpy-V impact tests at –60°C, –40°C, –20°C, 0°C and 20°C were carried out, as well as metallographic examination by both optical (OM and scanning electron microscopy (SEM, of specimens obtained entirely from the weld metal, allowing the discussion over the toughness X microstructure relationship. The weld metals have shown higher toughness levels in relation to the minimum required for use with low-alloy C-Mn steels welding with requirements of impact toughness of 27 J at 0°C for heat input up to 12 kJ/mm allowing an increase in productivity of 58% on the effective manufacturing time.

Disposal of low-level radioactive wastes. Plasma furnace for the treatment of low-level radwastes in Switzerland. Plasma furnace for the treatment of low-level radwastes in Switzerland

International Nuclear Information System (INIS)

Hoffelner, W.; Mueller, T.; Fuenfschilling, M.R.; Jacobi, A.; Eschenbach, R.; Lutz, H.R.; Vuilleumier, C.

1994-01-01

The treatment method to be applied consists of thermal decomposition and vitrification. The facility to be constructed at the Zwilag is a plasma-arc furnace, and planning activities are heading towards the final phase. There will be only this one facility for treating in only one process step solid, mixed wastes, liquid wastes, sludges, metals, and inorganic wastes, producing vitrified waste packages ready for ultimate storage as 200-l waste drums. The main features of the plasma-arc furnace are explained. (orig./HP) [de

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. Copyright © 2013 Elsevier B

Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65

International Nuclear Information System (INIS)

Hashemi, S. H.; Mohammadyani, D.

2011-01-01

The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

Energy Technology Data Exchange (ETDEWEB)

Eaton, W.C. [ed.

1995-05-31

This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace.

Test Plan: Phase 1 demonstration of 3-phase electric arc melting furnace technology for vitrifying high-sodium content low-level radioactive liquid wastes

International Nuclear Information System (INIS)

Eaton, W.C.

1995-01-01

This document provides a test plan for the conduct of electric arc vitrification testing by a vendor in support of the Hanford Tank Waste Remediation System (TWRS) Low-Level Waste (LLW) Vitrification Program. The vendor providing this test plan and conducting the work detailed within it [one of seven selected for glass melter testing under Purchase Order MMI-SVV-384216] is the US Bureau of Mines, Department of the Interior, Albany Research Center, Albany, Oregon. This test plan is for Phase I activities described in the above Purchase Order. Test conduct includes feed preparation activities and melting of glass with Hanford LLW Double-Shell Slurry Feed waste simulant in a 3-phase electric arc (carbon electrode) furnace

The effect of heat treatment on phosphorus segregation in a submerged-arc weld metal

International Nuclear Information System (INIS)

Beere, W.B.; Buswell, J.T.

1999-01-01

Intergranular fracture (IGF) has been observed in carbon-manganese steels after irradiation or high temperature exposure for prolonged periods. The effect is associated with an increase in the ductile-brittle transition temperature and has been related to phosphorus diffusion to grain boundaries. Phosphorus also diffuses thermally at the temperatures used for post-weld heat treatments such that in principle, the slightly different heat treatments given to different parts of a large vessel could lead to differing grain boundary phosphorus coverage and hence susceptibility to IGF. The effect of typical heat treatments on phosphorus coverage has been investigated using a finite difference model based on a theory that has been fitted to a wide range of constant temperature data. Regardless of previous history, the grain boundary coverage of phosphorus was predicted to depend on the final anneal and cooling rate. These differed insufficiently in the typical heat treatments to produce significant differences in segregation. It was concluded that the ductile-brittle transition temperature in submerged-arc welds would be unaffected in vessels that had seen typical post-weld heat treatments

Contribution to the study of an electric rotating furnace with gaseous electrodes

International Nuclear Information System (INIS)

Dallaire, Serge

1976-01-01

As the most primary and also most efficient way to transfer to a body the energetic content of an electric arc is to put it directly in contact with the arc, this research thesis reports the study of the development of a device allowing this operation: the electric rotating furnace with gaseous electrodes. In the first part, the author presents the furnace and its operation characteristics: thermal enclosure, heat source, hardware and installation description, operation characteristics. The second part reports the study of heat transfer phenomena: main determinations of the transfer coefficient, inverse problem, study of the thermal diffusivity with phase change, proposed solutions, and experimental study. The third part reports the search for boundary conditions and the study of furnace efficiency [fr

Heavy metal recovery from electric arc furnace steel slag by using hydrochloric acid leaching

Science.gov (United States)

Wei, Lim Jin; Haan, Ong Teng; Shean Yaw, Thomas Choong; Chuah Abdullah, Luqman; Razak, Mus'ab Abdul; Cionita, Tezara; Toudehdehghan, Abdolreza

2018-03-01

Electric Arc Furnace steel slag (EAFS) is the waste produced in steelmaking industry. Environmental problem such as pollution will occur when dumping the steel slag waste into the landfill. These steel slags have properties that are suitable for various applications such as water treatment and wastewater. The objective of this study is to develop efficient and economical chlorination route for EAFS extraction by using leaching process. Various parameters such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature are investigated to determine the optimum conditions. As a result, the dissolution rate can be determined by changing the parameters, such as concentration of hydrochloric acid, particle size of steel slag, reaction time and reaction temperature. The optimum conditions for dissolution rates for the leaching process is at 3.0 M hydrochloric acid, particle size of 1.18 mm, reaction time of 2.5 hour and the temperature of 90°C.

Single crystal growth of pure and Nd-doped Y2O3 by flotating zone method with Xe arc lamp imaging furnace

International Nuclear Information System (INIS)

Tsuiki, H.; Kitazawa, K.; Fueki, K.; Masumoto, T.; Shiroki, K.

1980-01-01

Single crystals of undoped and Nd-doped yttrium oxide were grown by the floating zone method with a Xe arc lamp imaging furnace. The crystals were grown in the and directions. Transparent and subgrain-free single crystals were obtained at a growth rate of 30-60 mm/h for the undoped yttrium oxide. Facets of the cubic [100] and [211] were observed though the high temperature phase of the crystal is hexagonal. Dislocation densities of undoped yttrium oxide are given. (orig./WE)

Fatigue assessment of a double submerged arc welded gas pipeline

Energy Technology Data Exchange (ETDEWEB)

Fazzini, Pablo; Otegui, Jose Luis [Universidad Nacional Mar del Plata, Mar del Plata (Argentina). Instituto de Ciencia y Tecnologia de Materiales (INTEMA); Teutonico, Mauricio; Manfredi, Carlos [GIE S.A., Mar del Plata (Argentina)

2005-07-01

An uncommon blowout in a 24'' diameter, 7 mm thick API 5L X52 gas pipeline was due to fracture at the longitudinal double submerged arc weld. Oddly enough for gas pipelines, it was found that fatigue cracks had propagated from a large embedded weld defect of lack of fusion resulting from severe geometrical mismatch between inner and outer weld passes. What makes this failure particularly interesting is that: previous in line inspections failed to detect any defect, no evidence of third party damage was found, and very few large pressure cycles had been recorded during the last 5 years of service, which were believed to be representative of the entire service life of the pipeline. Fatigue tests were carried out to characterize propagation of fatigue cracks in weld metal, it was found that a large Paris exponent made the few large amplitude cycles most contributing to crack propagation. Crack growth path and striation patterns were studied. Fatigue growth was modelled by integrating experimental results and by extrapolating striation spacing in the fracture surface of the failed pipe. Crack growth path and striation patterns were studied. It was found that microstructure discontinuities govern propagation at low {delta}K, but one striation per cycle was produced at large {delta}K, due to a mostly ductile propagation mode. Fatigue growth was modelled by integrating experimental results and by extrapolating striation spacing in the fracture surface of the failed pipe. It was found that in the early life of the line many more large pressure cycles than expected had occurred. Good correspondence between predicted and actual fatigue lives was in this way obtained (author)

Fatigue assessment of a double submerged arc welded gas pipeline

Energy Technology Data Exchange (ETDEWEB)

Fazzini, Pablo; Otegui, Jose Luis [Universidad Nacional Mar del Plata, Mar del Plata (Argentina). Instituto de Ciencia y Tecnologia de Materiales (INTEMA); Teutonico, Mauricio; Manfredi, Carlos [GIE S.A., Mar del Plata (Argentina)

2005-07-01

An uncommon blowout in a 24'' diameter, 7 mm thick API 5L X52 gas pipeline was due to fracture at the longitudinal double submerged arc weld. Oddly enough for gas pipelines, it was found that fatigue cracks had propagated from a large embedded weld defect of lack of fusion resulting from severe geometrical mismatch between inner and outer weld passes. What makes this failure particularly interesting is that: previous in line inspections failed to detect any defect, no evidence of third party damage was found, and very few large pressure cycles had been recorded during the last 5 years of service, which were believed to be representative of the entire service life of the pipeline. Fatigue tests were carried out to characterize propagation of fatigue cracks in weld metal, it was found that a large Paris exponent made the few large amplitude cycles most contributing to crack propagation. Crack growth path and striation patterns were studied. Fatigue growth was modelled by integrating experimental results and by extrapolating striation spacing in the fracture surface of the failed pipe. Crack growth path and striation patterns were studied. It was found that microstructure discontinuities govern propagation at low {delta}K, but one striation per cycle was produced at large {delta}K, due to a mostly ductile propagation mode. Fatigue growth was modelled by integrating experimental results and by extrapolating striation spacing in the fracture surface of the failed pipe. It was found that in the early life of the line many more large pressure cycles than expected had occurred. Good correspondence between predicted and actual fatigue lives was in this way obtained (author)

Removal of Heavy Metals from Steel Making Waste Water by Using Electric Arc Furnace Slag

Directory of Open Access Journals (Sweden)

C. L. Beh

2012-01-01

Full Text Available This work investigated the reduction of chemical oxygen demand (COD, biological oxygen demand (BOD, total suspended solids (TSS and the concentration of heavy metals of wastewater from a steel making plant. Adsorption experiments were carried out by electric arc furnace slag (EAFS in a fixed-bed column mode. The raw wastewater did not meet the standard B limitations, having high values of BOD, COD, TSS, Iron, Zinc, Manganese and Copper. After passing through the fixed bed column, BOD, COD and TSS values decreased to 1.6, 6.3 and <2 mgL-1, respectively while the concentration of Iron, Zinc, Manganese and Copper were 0.08, 0.01, 0.03 and 0.07 mgL-1, respectively. The results confirmed that EAFS can be used as an efficient adsorbent for producing treated water that comply with the Standard B limitations for an industrial effluent.

The application of imperialist competitive algorithm for optimization of deposition rate in submerged arc welding process using TiO{sub 2} nano particle

Energy Technology Data Exchange (ETDEWEB)

Ghaderi, Mohammad Reza; Eslampanah, Amirhossein; Ghaderi, Kianoosh [Islamic Azad University, Sanandaj (Iran, Islamic Republic of); Aghakhani, Masood [Razi University, Kermanshah (Iran, Islamic Republic of)

2015-01-15

We used a novel optimization algorithm based on the imperialist competitive algorithm (ICA) to optimize the deposition rate in the submerged arc welding (SAW) process. This algorithm offers some advantages such as simplicity, accuracy and time saving. Experiments were conducted based on a five factor, five level rotatable central composite design (RCCD) to collect welding data for deposition rate as a function of welding current, arc voltage, contact tip to plate distance, welding speed and thickness of TiO{sub 2} nanoparticles coated on the plates of mild steel. Furthermore, regression equation for deposition rate was obtained using least squares method. The regression equation as the cost function was optimized using ICA. Ultimately, the levels of input variables to achieve maximum deposition rate were obtained using ICA. Computational results indicate that the proposed algorithm is quite effective and powerful in optimizing the cost function.

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

Structural ceramics containing electric arc furnace dust

International Nuclear Information System (INIS)

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

2013-01-01

Highlights: • Zn is stabilized due to formation of ZnAl 2 O 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 an

Processing precious metals in a top-blown rotary converter

Science.gov (United States)

Whellock, John G.; Matousek, Jan W.

1990-09-01

Copper-nickel/platinum-palladium flotation concentrates produced by the Stillwater Mining Company were smelted and refined in an integrated pilot plant consisting of a submerged-arc electric furnace and top-blown rotary converter. The conversion of high-iron electric furnace mattes was achieved with apparent oxygen efficiencies in excess of 100 percent. Platinum and palladium recoveries averaged 99 percent, and copper and nickel recoveries were 94 percent.

Submergence rice cultivation in southern Bangladesh: farmers opinion and adaptations practices

Directory of Open Access Journals (Sweden)

AKM Abdul Ahad Biswas

2015-12-01

Full Text Available Rice productivity in coastal Bangladesh is lower than the national average and total coastal area is considered to be submergence-prone and higher vulnerable in July to January cropping season. The selected study areas are Kalapara and Patuakhali Sadar Upazila that are too vulnerable to agriculture practices. Field survey was conducted during 01st June to 30th July, 2015 to investigate the impact of submergence on Aman rice cultivation (ARC, existing adopted local adaptation practices with impacts and options to address the submergence problem. Primary data was collected through Focus Group Discussion (FGD, Individual Interview and Key Informant Interview methods and secondary data was collected from different secondary sources. A well-structured pretested questionnaire schedule was developed keeping in mind the objectives and variables under this study. After cyclone SIDR and AILA devastation, the rate of traditional ARC is decreasing every year and in 2015 it was 26.51%. Recently farmers have adopted new cropping practices and strategies like modern ARC in Aman season as single crop; Boro-Aus-Aman season as triple crop and Aus-Aman season as double crop are practicing. Approximately all farmers have adopted to grow stress tolerant rice varieties (STRV; farmer’s curiosities to familiar with and to have the STRV are encouraging. Farmers were fully adopted BRRIdhan52 rice cultivation with positive perceptions of higher yield and lower production cost. Therefore it can be concluded that the intensity of adoption of adaptation and mitigation measures are significantly influenced positively by the STRV yield capability; farmer’s participation in intervention programs; livelihood diversification; frequency of extension personnel contact; submergence and inundation characteristics; tolerance attributes of STRV and availability of STRV cultivation information.International Journal of Environment Vol.4(4 2015: 100-113

Intelligent Support System of Steel Technical Preparation in an Arc Furnace: Functional Scheme of Interactive Builder of the Multi Objective Optimization Problem

Science.gov (United States)

Logunova, O. S.; Sibileva, N. S.

2017-12-01

The purpose of the study is to increase the efficiency of the steelmaking process in large capacity arc furnace on the basis of implementation a new decision-making system about the composition of charge materials. The authors proposed an interactive builder for the formation of the optimization problem, taking into account the requirements of the customer, normative documents and stocks of charge materials in the warehouse. To implement the interactive builder, the sets of deterministic and stochastic model components are developed, as well as a list of preferences of criteria and constraints.

The grain boundary segregation of phosphorus in thermally aged and irradiated C-Mn submerged-are weld metal

International Nuclear Information System (INIS)

Mendes, C.M.

1999-01-01

The segregation of free phosphorus atoms to grain boundaries in C-Mn steels has been identified as an embrittlement mechanism. A change in the brittle fracture mechanism from transgranular to intergranular has been observed for materials with higher phosphorus grain boundary coverage. The grain boundary segregation of phosphorus in various steels used in the nuclear power industry has been thermodynamically and kinetically modelled mostly with the Langmuir-McLean model. Recent publications have also suggested that neutron irradiation can affect segregation and various attempts at modelling this are currently under way. The present paper describes a data base assembled on phosphorus grain boundary coverage measured by Auger electron spectroscopy on thermally aged and irradiated C-Mn submerged-arc weld specimens. Software tools were developed to evaluate the changes in phosphorus grain boundary coverage associated with instantaneous temperature changes and temperature gradients. The phosphorus free energy change associated with grain boundary segregation was modelled from the thermally aged data and used with the software to determine the phosphorus segregation in submerged-arc weld metals following the post weld stress relief heat treatments received prior to plant operation. The phosphorus grain boundary coverage changes arising from the thermal history of submerged-arc weld materials during irradiation were also modelled and found to compare well with data obtained on irradiated materials. It was concluded that under the irradiation conditions sampled, phosphorus grain boundary segregation in submerged-arc weld materials can be modelled successfully using only the thermal term without appealing to an irradiation induced segregation process. (author)

Double-Sided Single-Pass Submerged Arc Welding for 2205 Duplex Stainless Steel

Science.gov (United States)

Luo, Jian; Yuan, Yi; Wang, Xiaoming; Yao, Zongxiang

2013-09-01

The duplex stainless steel (DSS), which combines the characteristics of ferritic steel and austenitic steel, is used widely. The submerged arc welding (SAW) method is usually applied to join thick plates of DSS. However, an effective welding procedure is needed in order to obtain ideal DSS welds with an appropriate proportion of ferrite (δ) and austenite (γ) in the weld zone, particularly in the melted zone and heat-affected zone. This study evaluated the effectiveness of a high efficiency double-sided single-pass (DSSP) SAW joining method for thick DSS plates. The effectiveness of the converse welding procedure, characterizations of weld zone, and mechanical properties of welded joint are analyzed. The results show an increasing appearance and continuous distribution feature of the σ phase in the fusion zone of the leading welded seam. The converse welding procedure promotes the σ phase to precipitate in the fusion zone of leading welded side. The microhardness appears to significantly increase in the center of leading welded side. Ductile fracture mode is observed in the weld zone. A mixture fracture feature appears with a shear lip and tears in the fusion zone near the fusion line. The ductility, plasticity, and microhardness of the joints have a significant relationship with σ phase and heat treatment effect influenced by the converse welding step. An available heat input controlling technology of the DSSP formation method is discussed for SAW of thick DSS plates.

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Modeling of thermal plasma arc technology FY 1994 report

International Nuclear Information System (INIS)

Hawkes, G.L.; Nguyen, H.D.; Paik, S.; McKellar, M.G.

1995-03-01

The thermal plasma arc process is under consideration to thermally treat hazardous and radioactive waste. A computer model for the thermal plasma arc technology was designed as a tool to aid in the development and use of the plasma arc-Joule beating process. The value of this computer model is to: (a) aid in understanding the plasma arc-Joule beating process as applied to buried waste or exhumed buried waste, (b) help design melter geometry and electrode configuration, (c) calculate the process capability of vitrifying waste (i.e., tons/hour), (d) develop efficient plasma and melter operating conditions to optimize the process and/or reduce safety hazards, (e) calculate chemical reactions during treatment of waste to track chemical composition of off-gas products, and composition of final vitrified waste form and (f) help compare the designs of different plasma-arc facilities. A steady-state model of a two-dimensional axisymmetric transferred plasma arc has been developed and validated. A parametric analysis was performed that studied the effects of arc length, plasma gas composition, and input power on the temperatures and velocity profiles of the slag and plasma gas. A two-dimensional transient thermo-fluid model of the US Bureau of Mines plasma arc melter has been developed. This model includes the growth of a slag pool. The thermo-fluid model is used to predict the temperature and pressure fields within a plasma arc furnace. An analysis was performed to determine the effects of a molten metal pool on the temperature, velocity, and voltage fields within the slag. A robust and accurate model for the chemical equilibrium calculations has been selected to determine chemical composition of final waste form and off-gas based on the temperatures and pressures within the plasma-arc furnace. A chemical database has been selected. The database is based on the materials to be processed in the plasma arc furnaces

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.

Thermodynamic analysis of the selective chlorination of electric arc furnace dust

International Nuclear Information System (INIS)

Pickles, C.A.

2009-01-01

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.

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.

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.

The influence of plate thickness on the welding residual stresses from submerged arc welding in offshore steel structures

DEFF Research Database (Denmark)

Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen

2017-01-01

Welding-induced residual tensile stresses and distortion have become a major concern in relation to the structural integrity of welded structures within the offshore wind industry. The stresses have a negative impact on the integrity of the welded joint, as they promote distortion, reduce fatigue...... leading to a better understanding of the distribution and development of the welding residual stresses. This can later be used to optimize the fatigue design, providing a more efficient and improved design. In this context, the current research is expected to benefit the offshore industry by leading...... to an improved design, which consequently may be included in future norms and standards. Submerged Arc Welding (SAW) was used to make a fully penetrated butt weld in 10 mm and 40 mm thick steel plates with the same welding parameters as used in the production procedures. The base material is thermomechanical hot...

Submerged Arc Stainless Steel Strip Cladding—Effect of Post-Weld Heat Treatment on Thermal Fatigue Resistance

Science.gov (United States)

Kuo, I. C.; Chou, C. P.; Tseng, C. F.; Lee, I. K.

2009-03-01

Two types of martensitic stainless steel strips, PFB-132 and PFB-131S, were deposited on SS41 carbon steel substrate by a three-pass submerged arc cladding process. The effects of post-weld heat treatment (PWHT) on thermal fatigue resistance and hardness were evaluated by thermal fatigue and hardness testing, respectively. The weld metal microstructure was investigated by utilizing optical microscopy, scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDS) and transmission electron microscopy (TEM). Results showed that, by increasing the PWHT temperature, hardness decreased but there was a simultaneous improvement in weldment thermal fatigue resistance. During tempering, carbide, such as (Fe, Cr)23C6, precipitated in the weld metals and molybdenum appeared to promote (Fe, Cr, Mo)23C6 formation. The precipitates of (Fe, Cr, Mo)23C6 revealed a face-centered cubic (FCC) structure with fine grains distributed in the microstructure, thereby effectively increasing thermal fatigue resistance. However, by adding nickel, the AC1 temperature decreased, causing a negative effect on thermal fatigue resistance.

Further contribution to the study of buffer layer on austenitic stainless stell overlays obtained by means of automatic submerged arc welding with electrode-wire

International Nuclear Information System (INIS)

Colla, G.

1988-01-01

The influence of several buffer layer types on a 308 type austenitic stainless steel surface overlay having a 19-21% chromium and 10-12% nikel content have been analysed. Cladding passes have been deposited on carbon steel test samples by using automatic submerged arc welding process with electrode-wire. The experimental tests have involved buffer layers having seven different chemical compositions and the obtained results are reported and discussed in the paper. The achieved experimetal results allow selecting the most suitable buffer layer to be deposited in order to reach the required cladding performance in service

Analytical model of stress field in submerged arc welding butt joint with thorough penetration

Directory of Open Access Journals (Sweden)

Winczek Jerzy

2018-01-01

Full Text Available Analytical model of temporary and residual stresses for butt welding with thorough penetration was described assuming planar section hypothesis and using integral equations of stress equilibrium of the bar and simple Hooke’s law. In solution the effect of phase transformations (structure changes and structural strains has been taken into account. Phase transformations during heating are limited by temperature values at the beginning and at the end of austenitic transformation, depending on chemical composition of steel while the progress of phase transformations during cooling is determined on the basis of TTT-welding diagram. Temperature values at the beginning and at the end of transformation are conditioned by the speed of heating. Kinetics of diffusional transformation is described basing on Johnson-Mehl-Avrami-Kolmogorov equation, while martensitic transformation, basing on Koistinen-Marburger equation. Stresses in elasto-plastic state are determined by iteration, using elastic solutions method with changeable longitudinal modulus of elasticity, conditioned by stress-strain curve. Computations of stress field have been conducted for one-side butt welded of two steel flats made from S235 steel. It has enabled a clear interpretation of influence of temperature field and phase transformation on stresses caused by welding using Submerged Arc Welding (SAW method.

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.

Increase in the efficiency of electric melting of pellets in an arc furnace with allowance for the energy effect of afterburning of carbon oxide in slag using fuel-oxygen burners

Science.gov (United States)

Stepanov, V. A.; Krakht, L. N.; Merker, E. E.; Sazonov, A. V.; Chermenev, E. A.

2015-12-01

The problems of increasing the efficiency of electric steelmaking using fuel-oxygen burners to supply oxygen for the afterburning of effluent gases in an arc furnace are considered. The application of a new energy-saving regime based on a proposed technology of electric melting is shown to intensify the processes of slag formation, heating, and metal decarburization.

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.

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.

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.

Fabrication of TiO2/Carbon Photocatalyst using Submerged DC Arc Discharged in Ethanol/Acetic Acid Medium

Science.gov (United States)

Saraswati, T. E.; Nandika, A. O.; Andhika, I. F.; Patiha; Purnawan, C.; Wahyuningsih, S.; Rahardjo, S. B.

2017-05-01

This study aimed to fabricate a modified photocatalyst of TiO2/C to enhance its performance. The fabrication was achieved using the submerged direct current (DC) arc-discharge method employing two graphite electrodes, one of which was filled with a mixture of carbon powder, TiO2, and binder, in ethanol with acetic acid added in various concentrations. The arc-discharge method was conducted by flowing a current of 10-20 A (~20 V). X-ray diffraction (XRD) patterns showed significant placements of the main peak characteristics of TiO2, C graphite, and titanium carbide. The surface analysis using Fourier transform infrared spectroscopy (FTIR) revealed that fabricated TiO2/C nanoparticles had stretching vibrations of Ti-O, C-H, C═O, C-O, O-H and C═C in the regions of 450-550 cm-1, 2900-2880 cm-1, 1690-1760 cm-1, 1050-1300 cm-1, 3400-3700 cm-1 and ~1600 cm-1, respectively. In addition, the study investigated the photocatalysts of unmodified and modified TiO2/C for photodegradation of methylene blue (MB) dye solution under mercury lamp irradiation. The effectiveness of the degradation was defined by the decrease in 60-minute absorbance under a UV-Vis spectrophotometer. Modified TiO2/C proved to be significantly more efficient in reducing dye concentrations, reaching ~70%. It indicated that the oxygen-containing functional groups have been successfully attached to the surface of the nanoparticles and played a role in enhancing photocatalytic activity.

Driven Motion and Instability of an Atmospheric Pressure Arc

International Nuclear Information System (INIS)

Max Karasik

1999-01-01

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

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.

Metallurgical and mechanical characterization of a submerged arc welded joint in a 316 type stainless steel

International Nuclear Information System (INIS)

Piatti, G.; Vedani, M.

1990-01-01

The tensile (deformation and fracture) behaviour of a multipass submerged arc welded joint Type 316 stainless steel is investigated by tests at room temperature and at 400 0 C on all-weld metal and transverse to weld (composite) specimens as well as by microstructural and compositional analyses (optical, scanning electron and transmission electron microscopy). The as-deposited metal is characterised by a systematic variation in the tensile properties across the thickness with the higher strength and the lower ductility in the weld centre. These variations are related to material variability (mainly in dislocation density) because of local dissimilarities in thermal and mechanical histories occurring during the welding process. However, the material variability in the fusion zone, although important is not so large in the present weld and it does not influence the tensile properties of the weld as a whole. Moreover, the tensile behaviour concerning the transverse to weld specimens is characterized by a supporting effect from the higher yield strength material zone (fusion zone) to the lower yield strength material zone (parent metal) justified by the different contribution of the parent metal and of the weld-deposit metal to the integral plastic strain of the specimens. (author)

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.

Presentation of the Vulcano installation which uses a plasma transferred arc rotary furnace for corium melting

International Nuclear Information System (INIS)

Cognet, G.; Laffont, G.; Jegou, C.; Pierre, J.; Journeau, C.; Sudreau, F.; Roubaud, A.

1998-01-01

In the case of loss coolant accident, the reactor core could melt and turn into a mixture of uranium oxides, zirconium, iron and steel called corium. A large experimental program has been launched to study corium behaviour, to qualify solutions to stabilize it and to confine it in the reactor containment. The Vulcano installation has been designed to that purpose. It is made up of: i) a plasma transferred arc rotary furnace, ii) a testing surface covered with refractory materials, iii) an induction heating system in order to simulate the residual power of corium, iv) instrumentation devices such as video cameras, thermocouples, infra-red pyrometers and flowmeters, and v) a laboratory to perform chemical analysis of corium samples. The first experimental results show that a mixture of corium and concrete spreads better than expected. It seems that a low initial height of matter can produce a great distance flowing while having a chaotic behaviour. This characteristic suggests that the mixture acts as a Bingham type threshold fluid. (A.C.)

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)

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

International Nuclear Information System (INIS)

Penalva, I.; Damborenea, J.; Legarda, F.; Zuloaga, P.; Ordonez, M.; Serrano, I.

2006-01-01

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 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

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

Study of the processes for of remelting zirconium alloys in an electric arc furnace

Energy Technology Data Exchange (ETDEWEB)

Pereira, Luiz A.T.; Rossi, Jesualdo L.; Costa, Guilherme R.; Martinez, Luis G.; Sato, Ivone M., E-mail: luiz.atp@uol.com.br, E-mail: jelrossi@ipen.br, E-mail: guilhermeramoscosta@gmail.com, E-mail: lgallego@ipen.br, E-mail: imsato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2015-07-01

Zirconium alloy tubes are used as cladding for fuel elements of PWR nuclear reactors, which contains the UO{sub 2} pellets. In the manufacture of these fuel element parts, machining chips from the nuclear grade zirconium alloys are generated. Hence, these machining chips cannot be discarded, as ordinary metallic waste. Thus, the recycling of this material is a strategic aspect for the nuclear technology, both for economic and environmental issues. The main reason is that nuclear grade alloys have very high cost, are not commercially produced in Brazil and has to be imported for the manufacture of the nuclear fuels. This work discusses a method to melt and recycle Zircaloy chips, using an electric-arc furnace to obtain small laboratory ingots. The chemical composition of the ingots was determined using X-ray fluorescence spectroscopy and was compared to the specifications of nuclear grade Zircaloy and to the chemical composition of the received machining chips. The ingots were annealed in high vacuum, as well as were hot rolled in a mill. The microstructures were characterized by optical microscopy. The hardness was evaluated using the Rockwell B scale hardness. The results showed that the compositions of the recycled Zircaloy comply with the chemical specifications and a suitable microstructure has been obtained for nuclear use. (author)

Development of processes for zircaloy chips recycling by electric arc furnace remelting and powder metallurgy

International Nuclear Information System (INIS)

Pereira, Luiz Alberto Tavares

2014-01-01

PWR reactors employ, as nuclear fuel, UO 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)

Arc melting and homogenization of ZrC and ZrC + B alloys

Science.gov (United States)

Darolia, R.; Archbold, T. F.

1973-01-01

A description is given of the methods used to arc-melt and to homogenize near-stoichiometric ZrC and ZrC-boron alloys, giving attention to the oxygen contamination problem. The starting material for the carbide preparation was ZrC powder with an average particle size of 4.6 micron. Pellets weighing approximately 3 g each were prepared at room temperature from the powder by the use of an isostatic press operated at 50,000 psi. These pellets were individually melted in an arc furnace containing a static atmosphere of purified argon. A graphite resistance furnace was used for the homogenization process.

Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI Series 5

International Nuclear Information System (INIS)

Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O.; Menke, B.H.

1992-10-01

The Fifth Irradiation Series in the Heavy-Section Steel Irradiation Program obtained a statistically significant fracture toughness data base on two high-copper (0.23 and 0.31 wt %) submerged-arc welds to determine the shift and shape of the K Ic curve as a consequence of irradiation. Compact specimens with thicknesses to 101.6 mm (4 in) in the irradiated condition and 203.2 mm (8 in) in the unirradiated condition were tested, in addition to Charpy impact, tensile, and drop-weight specimens. Irradiations were conducted at a nominal temperature of 288 degree C and an average fluence of 1.5 x 10 19 neutrons/cm 2 (>l MeV). The Charpy 41-J temperature shifts are about the same as the corresponding drop-weight NDT temperature shifts. The irradiated welds exhibited substantial numbers of cleavage pop-ins. Mean curve fits using two-parameter (with fixed intercept) nonlinear and linearized exponential regression analysis revealed that the fracture toughness 100 MPa lg-bullet √m shifts exceeded the Charpy 41-J shifts for both welds. Analyses of curve shape changes indicated decreases in the slopes of the fracture toughness curves, especially for the higher copper weld. Weibull analyses were performed to investigate development of lower bound curves to the data, including the use of a variable K min parameter which affects the curve shape

Utilization of Electric Arc Furnace Dust as raw material for the production of ceramic and concrete building products.

Science.gov (United States)

Sikalidis, Constantine; Mitrakas, Manassis

2006-01-01

The up to 20 wt% addition of the Electric Arc Furnace Dust (EAFD) hazardous waste on the properties of extruded clay-based ceramic building products fired at various temperatures (850 to 1050 degrees C), as well as of dolomite-concrete products was investigated. Chemical, mineralogical and particle size distribution analyses were performed in order to characterize the used EAFD. The results showed that the ceramic specimens prepared had water absorption, firing shrinkage, apparent density, mechanical strength, colour and leaching behaviour within accepted limits. Addition of 7.5 to 15 wt% EAFD presented improved properties, while 20 wt% seems to be the upper limit. Dolomite-concrete specimens were prepared by vibration and press-forming of mixtures containing cement, sand, dolomite, EAFD and water. Modulus of rupture values were significantly increased by the addition of EAFD. The leaching tests showed stabilization of all toxic metals within the sintered ceramic structure, while the leaching behaviour of lead in dolomite-concrete products needs further detailed study.

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.

Reducción carbotérmica de pirolusita para la obtención de ferromanganeso y escoria, adecuados al desarrollo de materiales de soldadura

OpenAIRE

Cruz-Crespo, A.; García-Sánchez, L. L.; Quintana-Puchol, R.; Perdomo-González, L.; Gómez-Pérez, C. R.; Jiménez-Vielsa, G. E.; Cores-Sánchez, A.

2004-01-01

The high carbon ferromanganese obtained by means of carbothermic reduction in an electric arc furnace of direct current is proposed. The ideal composition of slag oxides to achieve a flux to be used in the submerged arc welding (SAW) is established. Calculation for charge components (pirolusite, coke, steel wool, lime, rutile and fluorite) for no fluxes technology for FeMn is carried out taking into account the welding fluxes characteristics of the SiO₂-MnO-CaO system. ...

Thermal Analysis on the Pyrolysis of Tetrabromobisphenol A and Electric Arc Furnace Dust Mixtures

Science.gov (United States)

Al-Harahsheh, Mohammad; Al-Otoom, Awni; Al-Jarrah, Muhannad; Altarawneh, Mohammednoor; Kingman, Sam

2018-02-01

The pyrolysis of Tetrabromobisphenol A (TBBPA) mixed with electric arc furnace dust (EAFD) was studied using thermogravimetric analysis (TGA) and theoretically analyzed using thermodynamic equilibrium calculations. Mixtures of both materials with varying TBBPA loads (1:1 and 1:3) were prepared and pyrolyzed in a nitrogen atmosphere under dynamic heating conditions at heating rates of 5 and 10 °C/min. The mixtures degraded through several steps, including decomposition of TBBPA yielding mainly HBr, bromination of metal oxides, followed by their evaporation in the sequence of CuBr3, ZnBr2, PbBr2, FeBr2, MnBr2, KBr, NaBr, CaBr2, and MgBr2, and finally reduction of the remaining metal oxides by the char formed from decomposition of TBBPA. Thermodynamic calculations suggest the possibility of selective bromination of zinc and lead followed by their evaporation, leaving iron in its oxide form, while the char formed may serve as a reduction agent for iron oxides into metallic iron. However, at higher TBBPA volumes, iron bromide forms, which can also be evaporated at a temperature higher than those of ZnBr2 and PbBr2. Results from this work provide practical insight into selective recovery of valuable metals from EAFD while at the same time recycling the hazardous bromine content in TBBPA.

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.

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)

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.

US bureau of mines small-scale arc melter tests

International Nuclear Information System (INIS)

O'Connor, W.K.; Oden, L.L.; Turner, P.C.; Davis, D.L.

1993-01-01

The US Bureau of Mines, in cooperation with the Idaho National Engineering Laboratory (INEL), conducted over 30 hours of melting tests to vitrify simulated low-level radioactive wastes from the INEL. Radioactive Waste Management Complex (RWMC). Five separate waste compositions were investigated, each consisting of noncontaminated soil from the RWMC and surrogate materials used to simulate the actual buried wastes. The RWMC soil and five waste compositions were melted in a 50-lb, single-phase electric arc furnace with a water-cooled shell. These tests were conducted to determine melting parameters in preparation for a large-scale melting campaign to be conducted in the Bureau's 1-metric ton (mt), water-cooled-wall, 3-phase electric arc furnace. Bulk chemical composition was determined for each of the feed materials and for the slag, metal, fume solids, and offgas furnace products, and distributions were calculated for the key elements. The material balance for the furnace operation indicates that from 63 to 84 pct of the feed reported to the slag. Cerium, used as the surrogate for the radionuclides in the wastes, demonstrated an extremely strong affinity for the slag product. Although slag temperatures as low as 1,250 C were recorded when melting the RWMC soil, temperatures in excess of 1,600 C were necessary to achieve the fluidity required for a successful slag tap

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.

Arc melter demonstration baseline test results

International Nuclear Information System (INIS)

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

Effect of addition of arc furnace dust in the microstructural properties of fly ash alkali-activated

International Nuclear Information System (INIS)

Vargas, Alexandre Silva de; Pavao, Bruno Barreto; Masuero, Angela Boreges; Dal Molin, Denise Carpena Coitinho; Vilela, Antonio Cezar Faria

2010-01-01

The search for alternative materials for construction, with less environmental impact, has been the subject of several studies. The alkali-activated cements have shown potential for the reuse of waste, and can be used in the technology of solidification/stabilization. Thus, this study aims to evaluate the main effect of adding arc furnace dust (AFD) in the microstructural properties of matrices based on fly ash alkali-activated. Three levels of AFD were studied: 0, 5, 15 and 25%. The curing was set at 70°C/24 h, and after, kept at room temperature until the age of analysis - 1, 28 and 180 days, with XRD and FTIR analysis. In the XRD spectres it was found that compounds of albite and natron decrease the intensity of their peaks in that there is an increase in the levels of AFD. Concerning to the FTIR, we observed that the band characteristic of the fly ash (FA) 1084 cm"-"1 was shifted to bands near 1000 cm"-"1, which shows that the residue does not interfere in the polymerization and aluminosilicate gel formation. Therefore, under the microstructural aspect, there were no major changes that would impair the use of this residue in alkali-activated matrices. (author)

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. Copyright © 2015 Elsevier Ltd. All rights reserved.

Waste form development for a DC arc furnace

Energy Technology Data Exchange (ETDEWEB)

Feng, X.; Bloomer, P.E.; Chantaraprachoom, N.; Gong, M.; Lamar, D.A.

1996-09-01

A laboratory crucible study was conducted to develop waste forms to treat nonradioactive simulated {sup 238}Pu heterogeneous debris waste from Savannah River, metal waste from the Idaho National Engineering Laboratory (INEL), and nominal waste also from INEL using DC arc melting. The preliminary results showed that the different waste form compositions had vastly different responses for each processing effect. The reducing condition of DC arc melting had no significant effects on the durability of some waste forms while it decreased the waste form durability from 300 to 700% for other waste forms, which resulted in the failure of some TCLP tests. The right formulations of waste can benefit from devitrification and showed an increase in durability by 40%. Some formulations showed no devitrification effects while others decreased durability by 200%. Increased waste loading also affected waste form behavior, decreasing durability for one waste, increasing durability by 240% for another, and showing no effect for the third waste. All of these responses to the processing and composition variations were dictated by the fundamental glass chemistry and can be adjusted to achieve maximal waste loading, acceptable durability, and desired processing characteristics if each waste formulation is designed for the result according to the glass chemistry.

Synthesis of aluminium nanoparticles by arc evaporation of an ...

Indian Academy of Sciences (India)

Administrator

Abstract. 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.

Arc plasma incineration of surrogate radioactive wastes

International Nuclear Information System (INIS)

Girold, C.; Cartier, R.; Taupiac, J.P.; Vandensteendam, C.; Baronnet, J.M.

1995-01-01

The aim of this presentation is to demonstrate the feasibility to substitute a single plasma reactor, where the arc is transferred on a melt glass bath, for several steps in an existing nuclear technological wastes incinerator. The incineration of wastes, the produced gas treatment and the vitrification of ashes issued from waste incineration are the three simultaneous functions of this new kind of reactor. The three steps of the work are described: first, post-combustion in an oxygen plasma of gases generated from the waste pyrolysis, then, vitrification of ashes from the calcination of wastes in the transferred plasma furnace and finally, incineration/vitrification of wastes in the same furnace

IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

Directory of Open Access Journals (Sweden)

MAJID ALI

2013-04-01

Full Text Available The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH and sodium thiosulphate (Na2S2O3 in water to remove the gaseous iodine (I2 from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

Iodine Removal Efficiency in Non-Submerged and Submerged Self-Priming Venturi Scrubber

Energy Technology Data Exchange (ETDEWEB)

Ali, Majid; Yan, Changqi; Sun, Zhongning; Gu, Haifeng; Wang, Junlong; Mehboob; Khurram [Harbin Engineering Univ., Harbin (China)

2013-04-15

The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na{sub 2}S{sub 2}O{sub 3}) in water to remove the gaseous iodine (I{sub 2}) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber.

Iodine Removal Efficiency in Non-Submerged and Submerged Self-Priming Venturi Scrubber

International Nuclear Information System (INIS)

Ali, Majid; Yan, Changqi; Sun, Zhongning; Gu, Haifeng; Wang, Junlong; Mehboob; Khurram

2013-01-01

The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na 2 S 2 O 3 ) in water to remove the gaseous iodine (I 2 ) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine for submerged and non-submerged operating conditions. In the non-submerged venturi scrubber, only the droplets take part in iodine removal efficiency. However, in a submerged venturi scrubber condition, the iodine gas is absorbed from gas to droplets inside the venturi scrubber and from bubbles to surrounding liquid at the outlet of a venturi scrubber. Experimentally, it is observed that the iodine removal efficiency is greater in the submerged venturi scrubber as compare to a non-submerged venturi scrubber condition. The highest iodine removal efficiency of 0.99±0.001 has been achieved in a submerged self-priming venturi scrubber condition. A mathematical correlation is used to predict the theoretical iodine removal efficiency in submerged and non-submerged conditions, and it is compared against the experimental results. The Wilkinson et al. correlation is used to predict the bubble diameter theoretically whereas the Nukiyama and Tanasawa correlation is used for droplet diameter. The mass transfer coefficient for the gas phase is calculated from the Steinberger and Treybal correlation. The calculated results for a submerged venturi scrubber agree well with experimental results but underpredicts in the case of the non-submerged venturi scrubber

A mass spectrographic investigation of the methods for obtaining quantitative analyses for the mass balance of P and B through a submerged arc silicon smelter

International Nuclear Information System (INIS)

Rogers, D.E.C.; Jones, D.S.; Wegman, J.W.; Brain, L.; Van Wamelen, J.

1983-11-01

Mass spectrographic analyses of silica, silicon and silica reducing agents have been made using an arc discharge mass spectrograph. Analyses of certified standards and standard mixtures are given. An evaluation of doping techniques shows that the solid doping technique is satisfactory and that the liquid doping technique leads to significant errors. The amount of liquid dopant absorbed onto the substrate matrix varied from one compound to another and from one matrix to another. Comparison of analyses of solid-doped and undoped certified standards shows that all of the solid dopant is taken up by the sample. Analysis of silica reducing agents used in the arc reduction furnace shows that the major source of contamination by B and P is likely to be the coal and wood. Silica contains 0.4 ppm of B and 4 ppm of P and is a minor source of contamination. The levels in silicon are about 10 ppm for B and 20 ppm for P. A mass balance on P cannot be made and the missing amount is larger than the inaccuracy of the analysis. For analyses of feedstocks where the smelter outlet fumes are not sampled an accuracy of analysis to a factor of two is sufficient for the analysis of the coal and wood chips

Carbothermic reduction of pyrolusite for obtaining carbon bearing ferromanganese and slags, adequated to the development of welding materials

International Nuclear Information System (INIS)

Cruz-Crespo, A.; Garcia-Sanchez, L. L.; Quintana-Puchol, R.; Perdomo Gonzalez, L.; Gomez-Perez, C. R.; Jimenez-Vielsa, G. E.; Cores-Sanchez, A.

2004-01-01

The high carbon ferromanganese obtained by means of carbothermic reduction in an electric arc furnace of direct current is proposed. the ideal composition of slag oxides to achieve a flux to be used in the submerged arc welding (SAW) is established. Calculation for charge components (pyrolusite, coke, steel wool, lime, rutile and fluorite) for no fluxes technology for FeMn is carried out taking into account the welding fluxes characteristics of the SiO 2 -MnO-CaO system. Change materials reduction experiments to obtain FeMn and slag are used to develop a SAW flux. (Author) 21 refs

Carbothermic reduction of pyrolusite for obtaining carbon bearing ferromanganese and slags, adequated to the development of welding materials; Reduccion carbotermica de pirolusita para la obtencion de ferromanganeso y escoria, adecuados al desarrollo de materiales de soldadura

Energy Technology Data Exchange (ETDEWEB)

Cruz-Crespo, A.; Garcia-Sanchez, L. L.; Quintana-Puchol, R.; Perdomo Gonzalez, L.; Gomez-Perez, C. R.; Jimenez-Vielsa, G. E.; Cores-Sanchez, A.

2004-07-01

The high carbon ferromanganese obtained by means of carbothermic reduction in an electric arc furnace of direct current is proposed. the ideal composition of slag oxides to achieve a flux to be used in the submerged arc welding (SAW) is established. Calculation for charge components (pyrolusite, coke, steel wool, lime, rutile and fluorite) for no fluxes technology for FeMn is carried out taking into account the welding fluxes characteristics of the SiO{sub 2}-MnO-CaO system. Change materials reduction experiments to obtain FeMn and slag are used to develop a SAW flux. (Author) 21 refs.

Graphite electrode arc melter demonstration Phase 2 test results

International Nuclear Information System (INIS)

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

1996-06-01

Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau's Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of open-quotes as-receivedclose quotes heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process

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

International Nuclear Information System (INIS)

Mucsi, Cristiano Stefano

2005-01-01

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)

A New Method to Produce Ni-Cr Ferroalloy Used for Stainless Steel Production

Science.gov (United States)

Chen, Pei-Xian; Chu, Shao-Jun; Zhang, Guo-Hua

2016-08-01

A new electrosilicothermic method has been proposed in the present paper to produce Ni-Cr ferroalloy, which can be used for the production of 300 series stainless steel. Based on this new process, the Ni-Si ferroalloy is first produced as the intermediate alloy, and then the desiliconization process of Ni-Si ferroalloy melt with chromium concentrate is carried out to generate Ni-Cr ferroalloy. The silicon content in the Ni-Si ferroalloy produced in the submerged arc furnace should be more than 15 mass% (for the propose of reducing dephosphorization), in order to make sure the phosphorus content in the subsequently produced Ni-Cr ferroalloy is less than 0.03 mass%. A high utilization ratio of Si and a high recovery ratio of Cr can be obtained after the desiliconization reaction between Ni-Si ferroalloy and chromium concentrate in the electric arc furnace (EAF)-shaking ladle (SL) process.

Baseline tests for arc melter vitrification of INEL buried wastes. Volume 1: Facility description and summary data report

International Nuclear Information System (INIS)

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

1993-01-01

This report presents field results and raw data from the Buried Waste Integrated Demonstration (BWID) Arc Melter Vitrification Project Phase 1 baseline test series conducted by the Idaho National Engineering Laboratory (INEL) in cooperation with the U.S. Bureau of Mines (USBM). The baseline test series was conducted using the electric arc melter facility at the USBM Albany Research Center in Albany, Oregon. Five different surrogate waste feed mixtures were tested that simulated thermally-oxidized, buried, TRU-contaminated, mixed wastes and soils present at the INEL. The USBM Arc Furnace Integrated Waste Processing Test Facility includes a continuous feed system, the arc melting furnace, an offgas control system, and utilities. The melter is a sealed, 3-phase alternating current (ac) furnace approximately 2 m high and 1.3 m wide. The furnace has a capacity of 1 metric ton of steel and can process as much as 1,500 lb/h of soil-type waste materials. The surrogate feed materials included five mixtures designed to simulate incinerated TRU-contaminated buried waste materials mixed with INEL soil. Process samples, melter system operations data and offgas composition data were obtained during the baseline tests to evaluate the melter performance and meet test objectives. Samples and data gathered during this program included (a) automatically and manually logged melter systems operations data, (b) process samples of slag, metal and fume solids, and (c) offgas composition, temperature, velocity, flowrate, moisture content, particulate loading and metals content. This report consists of 2 volumes: Volume I summarizes the baseline test operations. It includes an executive summary, system and facility description, review of the surrogate waste mixtures, and a description of the baseline test activities, measurements, and sample collection. Volume II contains the raw test data and sample analyses from samples collected during the baseline tests

Three-dimensional numerical modelling of a magnetically deflected dc transferred arc in argon

CERN Document Server

Blais, A; Boulos, M I

2003-01-01

The aim of this work is to develop a numerical model for the deflection of dc transferred arcs using an external magnetic field as a first step into the modelling of industrial arc furnaces. The arc is deflected by the use of a conductor aligned parallel to the arc axis through which flows an electric current. The model is validated by comparing the results of axisymmetric calculations to modelling results from the scientific literature. The present model is found to be a good representation of the electric dc arc as differences with the literature are easily explained by model parameters such as the critical boundary conditions at the electrodes. Transferred arc cases exhibit the expected behaviour as the temperature T, the velocity v-vector and the electrical potential drop DELTA phi all increase with the arc current I and the argon flow rate Q. Three-dimensional geometry is implemented, enabling one to numerically deflect the arc. For the deflected arc cases, the deflection increases with the arc current I...

Graphite electrode arc melter demonstration Phase 2 test results

Energy Technology Data Exchange (ETDEWEB)

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

1996-06-01

Several U.S. Department of Energy organizations and the U.S. Bureau of Mines have been collaboratively conducting mixed waste treatment process demonstration testing on the near full-scale graphite electrode submerged arc melter system at the Bureau`s Albany (Oregon) Research Center. An initial test series successfully demonstrated arc melter capability for treating surrogate incinerator ash of buried mixed wastes with soil. The conceptual treatment process for that test series assumed that buried waste would be retrieved and incinerated, and that the incinerator ash would be vitrified in an arc melter. This report presents results from a recently completed second series of tests, undertaken to determine the ability of the arc melter system to stably process a wide range of {open_quotes}as-received{close_quotes} heterogeneous solid mixed wastes containing high levels of organics, representative of the wastes buried and stored at the Idaho National Engineering Laboratory (INEL). The Phase 2 demonstration test results indicate that an arc melter system is capable of directly processing these wastes and could enable elimination of an up-front incineration step in the conceptual treatment process.

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.

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.

Effect of clone size on submergence tolerance and post-submergence growth recovery in Carex brevicuspis (Cyperaceae

Directory of Open Access Journals (Sweden)

Zhengmiao Deng

2016-12-01

Full Text Available Clonal plants are prevalent in wetlands and play important roles in maintaining the functions of the ecosystem. In the present study, we determined the effect of clone sizes (R1, R2, and R3 comprising 1, 3, and 5clumping ramets on the tolerance of Carex brevicuspis growing under 30-cm-deep water to three different periods (one, two, and three months of submergence and its growth recovery one month after de-submergence. Our results showed that the relative growth rate (RGR of C. brevicuspis significantly declined with increasing submergence time, and was higher in R3 and R5 than in R1 plants under both submergence and post-submergence conditions. The concentration of water-soluble carbohydrates (WSCs was highest in R3, intermediate in R5, and the lowest in R1 plants during the first two months of submergence, indicating an optimal trade-off between energy investment and vegetative growth (i.e., buds and ramets production in C. brevicuspis. WSCs were significantly reduced with increasing submergence time, while the starch content was significantly reduced only during the third month of submergence, implying that WSCs were a direct energy source for C. brevicuspis during submergence. The number of buds was higher in R5 than in R3 and R1 plants after two and three months of submergence, which directly resulted in a significantly higher post-submergence ramet production in R5 plants. These results indicated that plants with relatively larger clone sizes display better tolerance to submergence stress and post-submergence growth recovery. Therefore, we speculate that the large clone size in C brevicuspis might be an effective adaptive mechanism to survive under submergence stress in floodplain wetlands.

The effect of smelting time and composition of palm kernel shell charcoal reductant toward extractive Pomalaa nickel laterite ore in mini electric arc furnace

Science.gov (United States)

Sihotang, Iqbal Huda; Supriyatna, Yayat Iman; Ismail, Ika; Sulistijono

2018-04-01

Indonesia is a country that is rich in natural resources. Being a third country which has a nickel laterite ore in the world after New Caledonia and Philippines. However, the processing of nickel laterite ore to increase its levels in Indonesia is still lacking. In the processing of nickel laterite ore into metal, it can be processed by pyrometallurgy method that typically use coal as a reductant. However, coal is a non-renewable energy and have high enough levels of pollution. One potentially replace is the biomass, that is a renewable energy. Palm kernel shell are biomass that can be used as a reductant because it has a fairly high fix carbon content. This research aims to make nickel laterite ores become metal using palm kernel shell charcoal as reductant in mini electric arc furnace. The result show that the best smelting time of this research is 60 minutes with the best composition of the reductant is 2,000 gram.

Three-dimensional numerical modelling of a magnetically deflected dc transferred arc in argon

International Nuclear Information System (INIS)

Blais, A; Proulx, P; Boulos, M I

2003-01-01

The aim of this work is to develop a numerical model for the deflection of dc transferred arcs using an external magnetic field as a first step into the modelling of industrial arc furnaces. The arc is deflected by the use of a conductor aligned parallel to the arc axis through which flows an electric current. The model is validated by comparing the results of axisymmetric calculations to modelling results from the scientific literature. The present model is found to be a good representation of the electric dc arc as differences with the literature are easily explained by model parameters such as the critical boundary conditions at the electrodes. Transferred arc cases exhibit the expected behaviour as the temperature T, the velocity v-vector and the electrical potential drop Δφ all increase with the arc current I and the argon flow rate Q. Three-dimensional geometry is implemented, enabling one to numerically deflect the arc. For the deflected arc cases, the deflection increases with the arc current I and conductor current I conductor and decreases with the flow rate Q and x 0 , the arc-conductor distance. These deflection behaviours are explained using physical arguments

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.)

Energy efficiency and the influence of gas burners to the energy related carbon dioxide emissions of electric arc furnaces in steel industry

International Nuclear Information System (INIS)

Kirschen, Marcus; Risonarta, Victor; Pfeifer, Herbert

2009-01-01

Determining the complete energy balance of an electric arc furnace (EAF) provides an appropriate method to examine energy efficiency and identify energy saving potentials. However, the EAF energy balance is complex due to the combined input of electrical energy and chemical energy resulting from natural gas (NG) combustion and oxidation reactions in the steel melt. In addition, furnace off-gas measurements and slag analysis are necessary to reliably determine energy sinks. In this paper 70 energy balances and energy efficiencies from multiple EAFs are presented, including data calculated from plant measurements and compiled from the literature. Potential errors that can be incorporated in these calculations are also highlighted. The total energy requirement of these modern EAFs analysed ranged from 510 to 880 kWh/t, with energy efficiency values (η = ΔH Steel /E Total ) of between 40% and 75%. Furthermore, the focus was placed on the total energy related CO 2 emissions of EAF processes comprising NG combustion and electrical energy input. By assessing multiple EAF energy balances, a significant correlation between the total energy requirement and energy related specific CO 2 emissions was not evident. Whilst the specific consumption of NG in the EAF only had a minor impact on the EAF energy efficiency, it decreased the specific electrical energy requirement and increased EAF productivity where transformer power was restricted. The analysis also demonstrated that complementing and substituting electrical energy with NG was beneficial in reducing the total energy related CO 2 emissions when a certain level of substitution efficiency was achieved. Therefore, the appropriate use of NG burners in modern EAFs can result in an increased EAF energy intensity, whilst the total energy related CO 2 emissions remain constant or are even decreased.

INFLUENCE OF THE MODERN SYSTEMS OF THE BLAST STEEL-FURNACE ELECTRICAL PARAMETERS CONTROL ON CAPACITY AND TECHNICAL AND ECONOMICAL INDICES OF MELTING

Directory of Open Access Journals (Sweden)

D. N. Andrianov

2006-01-01

Full Text Available The reduction of time under the current, electric energy rate, electrodes rate at working of arc steel-furnace with new transformer of capacity 95 MBA and with regulating system SIMELT-AC-NEC are noted.

Addition of electric arc furnace dust in hot metal changing the form of addition; Adicao de poeira de aciaria eletrica em ferro-gusa liquido alterando a forma de adicao

Energy Technology Data Exchange (ETDEWEB)

Marques Sobrinho, Vicente de Paulo Ferreira; Oliveira, Jose Roberto de; Vieira, Estefano Aparecido, E-mail: vicente@ifes.edu.br [Institulo Federal do Espirito Santo (IFES), ES (Brazil); Telles, Victor Bridi; Grillo, Felipe Fardin; Tenorio, Jorge Alberto Soares; Espinosa, Denise Crocce Romano [Universidade de Sao Paulo (USP), SP (Brazil). Escola Politecnica

2014-07-01

This research aims to study the incorporation of the mass of electric arc furnace dust (EAFD), by addition in hot metal (1.78% Si) at a temperature of 1,400 degrees Celsius. The EAFD is from a steel plant producing long steel. The addition of the EAFD was as received, in the form of briquettes without agitation of the hot metal and in the form of briquettes with agitation of the hot metal. Previously, the EAFD was characterized using the following techniques: chemical analysis, size analysis, X-ray diffraction, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The achievement of fusion experiments in laboratory scale, took place in a vertical tubular furnace with temperature control. The fusion experiments to assess the incorporation of EAFD mass used graphite crucibles. After cooling, the hot metal and the slag, remaining in the crucible, were weighed to do a mass balance. A flow of inert gas (argon) was maintained inside the furnace during the experiments. Results show that the experiment with addition of EAFD as received presents the best result of incorporating the mass of the final hot metal (1.73%) combined with the lowest percentage of volatilized mass of EAFD (46.52%). The experiment addition of EAFD in the form of briquette with agitation of hot metal presents the lowest percentage of slag mass (4.58%). The zinc content of volatilized EAFD (64.30%) is higher than the zinc content of the imported ore concentrate (52%) and zinc content of the national ore concentrate (12% to 39%). The presence of lead and cadmium in the slag characterizing it as a hazardous solid waste. (author)

Two-Dimensional Physical and CFD Modelling of Large Gas Bubble Behaviour in Bath Smelting Furnaces

Directory of Open Access Journals (Sweden)

Yuhua Pan

2010-09-01

Full Text Available The behaviour of large gas bubbles in a liquid bath and the mechanisms of splash generation due to gas bubble rupture in high-intensity bath smelting furnaces were investigated by means of physical and mathematical (CFD modelling techniques. In the physical modelling work, a two-dimensional Perspex model of the pilot plant furnace at CSIRO Process Science and Engineering was established in the laboratory. An aqueous glycerol solution was used to simulate liquid slag. Air was injected via a submerged lance into the liquid bath and the bubble behaviour and the resultant splashing phenomena were observed and recorded with a high-speed video camera. In the mathematical modelling work, a two-dimensional CFD model was developed to simulate the free surface flows due to motion and deformation of large gas bubbles in the liquid bath and rupture of the bubbles at the bath free surface. It was concluded from these modelling investigations that the splashes generated in high-intensity bath smelting furnaces are mainly caused by the rupture of fast rising large gas bubbles. The acceleration of the bubbles into the preceding bubbles and the rupture of the coalescent bubbles at the bath surface contribute significantly to splash generation.

Effectiveness of recycling light in ultra-bright short-arc discharge lamps.

Science.gov (United States)

Malul, Asher; Nakar, Doron; Feuermann, Daniel; Gordon, Jeffrey M

2007-10-17

Recycling light back into a plasma lamp's radiant zone can enhance its radiance. Measurements are reported for the effectiveness, spectral properties and modified plasma radiance maps that result from light recycling with a specular hemispherical mirror in commercial 150 W ultrabright Xenon short-arc discharge lamps, motivated by projection, biomedical and high-temperature furnace applications. For certain spectral windows and plasma arc regions, radiance can be heightened by up to 70%. However, the overall light recycling efficiency is reduced to about half this value due to lamp geometry. The manner in which light-plasma interactions affect light recycling efficacy is also elucidated.

Abrasion Wear Resistance, Hardness and Microstructure of Hard Linings Deposited by Means of a Submerged Arc. Dureza, microestructura y resistencia al desgaste por abrasion de recargues duros depositados con arco sumergido

Energy Technology Data Exchange (ETDEWEB)

Paranhos, R; Alcoforado, J M; Castillo, J A; Sauer, A

1989-01-01

Consumable materials for submerged arc welding of the types alloyed flux-neutral electrode and neutral flux-alloyed electrode were used to form, through multipass welding, a light alloy hard lining of the C-Mn type on ASTM A36 Type structural steel. Emphasis was put on microstructural characterization of the linings surveyed under electron scanning microscopy, and tests were performed to study their hardness and abrasion wear resistance at low pressures. As a result of these tests, a great influence of welding parameters on hardness and abrasion resistance properties of the combination active flux-neutral electrode was noticed. As the results showed no relationship between the hardness and the abrasion wear resistance of the linings surveyed, an attempt was made to relate the resulting microstructure with their abrasion wear resistance. (Author)

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

DC plasma arc melter technology for waste vitrification

International Nuclear Information System (INIS)

Hamilton, R.A.; Wittle, J.K.; Trescot, J.

1995-01-01

This paper describes the features and benefits of a breakthrough DC Arc Melter for the permanent treatment of all types of solid wastes including nonhazardous, hazardous and radioactive. This DC Arc Furnace system, now commercially available, is the low cost permanent solution for solid waste pollution prevention and remediation. Concern over the effective disposal of wastes generated by the industrial society, worldwide, has prompted development of technologies to address the problem. For the most part these technologies have resulted in niche solutions with limited application. The only solution that has the ability to process almost all wastes, and to recover/recycle metallic and inorganic matter, is the group of technologies known as melters. Melters have distinct advantages over traditional technologies such as incineration because melters operate at higher temperatures, are relatively unaffected by changes in the waste stream, produce a vitrified stable product, and have the capability to recover/recycle slag, metals and gas. The system, DC Plasma Arc Melter, has the lowest capital, maintenance and operating cost of any melter technology because of its patented DC Plasma Arc with graphite electrode. DC Plasma Arc Melter systems are commercially available in sizes from 50 kg/batch or 250--3,000 kg/hr on a continuous feed basis. This paper examines the design and operating benefits of a DC Plasma Arc Melter System

Mathematical modelling of heat transfer in dedusting plants and comparison to off-gas measurements at electric arc furnaces

International Nuclear Information System (INIS)

Kirschen, Marcus; Velikorodov, Viktor; Pfeifer, Herbert

2006-01-01

A mathematical simulation tool is presented in order to model enthalpy flow rates of off-gas and heat transfer of cooling systems at dedusting plants in electric steel making sites. The flexibility of the simulation tool is based on a user-defined series of modular units that describe elementary units of industrial dedusting systems, e.g. water-cooled hot gas duct, air injector, drop-out box, mixing chamber, post-combustion chamber, filter, etc. Results of simulation were checked with measurements at industrial electric steel making plants in order to validate the models for turbulence, heat transfer and chemical reaction kinetics. Comparison between computed and measured gas temperature and composition yield excellent agreement. The simulation tool is used to calculate off-gas temperature and volume flow rate, where off-gas measurements are very difficult to apply due to high gas temperatures and high dust load. Heat transfer from the off-gas to the cooling system was calculated in detail for a pressurised hot water EAF cooling system in order to investigate the impact of the cooling system and the dedusting plant operation on the energy sinks of the electric arc furnace. It is shown that optimum efficiency of post-combustion of EAF off-gas in the water-cooled hot gas duct requires continuous off-gas analysis. Common operation parameters of EAF dedusting systems do not consider the non-steady-state of the EAF off-gas emission efficiently

Mathematical modelling of heat transfer in dedusting plants and comparison to off-gas measurements at electric arc furnaces

Energy Technology Data Exchange (ETDEWEB)

Kirschen, Marcus [Institute for Industrial Furnaces and Heat Engineering, RWTH Aachen, Kopernikusstrasse 16, 52074 Aachen (Germany)]. E-mail: kirschen@iob.rwth-aachen.de; Velikorodov, Viktor [Institute for Industrial Furnaces and Heat Engineering, RWTH Aachen, Kopernikusstrasse 16, 52074 Aachen (Germany); Pfeifer, Herbert [Institute for Industrial Furnaces and Heat Engineering, RWTH Aachen, Kopernikusstrasse 16, 52074 Aachen (Germany)

2006-11-15

A mathematical simulation tool is presented in order to model enthalpy flow rates of off-gas and heat transfer of cooling systems at dedusting plants in electric steel making sites. The flexibility of the simulation tool is based on a user-defined series of modular units that describe elementary units of industrial dedusting systems, e.g. water-cooled hot gas duct, air injector, drop-out box, mixing chamber, post-combustion chamber, filter, etc. Results of simulation were checked with measurements at industrial electric steel making plants in order to validate the models for turbulence, heat transfer and chemical reaction kinetics. Comparison between computed and measured gas temperature and composition yield excellent agreement. The simulation tool is used to calculate off-gas temperature and volume flow rate, where off-gas measurements are very difficult to apply due to high gas temperatures and high dust load. Heat transfer from the off-gas to the cooling system was calculated in detail for a pressurised hot water EAF cooling system in order to investigate the impact of the cooling system and the dedusting plant operation on the energy sinks of the electric arc furnace. It is shown that optimum efficiency of post-combustion of EAF off-gas in the water-cooled hot gas duct requires continuous off-gas analysis. Common operation parameters of EAF dedusting systems do not consider the non-steady-state of the EAF off-gas emission efficiently.

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.

High Temperature Transparent Furnace Development

Science.gov (United States)

Bates, Stephen C.

1997-01-01

This report describes the use of novel techniques for heat containment that could be used to build a high temperature transparent furnace. The primary objective of the work was to experimentally demonstrate transparent furnace operation at 1200 C. Secondary objectives were to understand furnace operation and furnace component specification to enable the design and construction of a low power prototype furnace for delivery to NASA in a follow-up project. The basic approach of the research was to couple high temperature component design with simple concept demonstration experiments that modify a commercially available transparent furnace rated at lower temperature. A detailed energy balance of the operating transparent furnace was performed, calculating heat losses through the furnace components as a result of conduction, radiation, and convection. The transparent furnace shells and furnace components were redesigned to permit furnace operation at at least 1200 C. Techniques were developed that are expected to lead to significantly improved heat containment compared with current transparent furnaces. The design of a thermal profile in a multizone high temperature transparent furnace design was also addressed. Experiments were performed to verify the energy balance analysis, to demonstrate some of the major furnace improvement techniques developed, and to demonstrate the overall feasibility of a high temperature transparent furnace. The important objective of the research was achieved: to demonstrate the feasibility of operating a transparent furnace at 1200 C.

Joining of Materials with Diferent Properties Through Submerged Arc Welding Process and Destructive and Non-Destructive Testing of the Joints

Directory of Open Access Journals (Sweden)

Yakup Kaya

2013-01-01

Full Text Available In this study, X60, X65 and X70 steels used in petroleum and natural gas pipeline were joined with Submerged Arc Welding by using different type of welding fluxes (LN761 and P223 and wires (S1 and S2Mo. Initially, visual and radiographic inspection techniques were subjected to welded joints for determining surface and subsurface defects. After that, spectral analyses were carried out in order to determine the compositions of wire-flux-base metal on the joints. Impact toughness test were performed for determining toughness properties the joints. Furthermore, hardness and microstructure studies were also carried out on the samples. As a result of the visual and radiographic inspection on the welded samples, there were no weld defects on joints were observed. It was clearly understood that carbon ratio in the compositions of weld metal higher than base metal but lower than filler metal in terms of spectral analyses results. According to impact toughness test results, the joints obtained by using S2Mo welding wire and P223 welding flux had better impact toughness value than the joints obtained by S1 welding wire and LN 761 welding flux. With respect to hardness test, the highest hardness values were measured on weld metal. When the microstructure images were examined, it is clearly understood that similar images for all the joints were shown adjacent zones to weld metals heat affected zones and welding boundary, due to heat input constant.

Characterization of Ladle Furnace Slag from Carbon Steel Production as a Potential Adsorbent

Directory of Open Access Journals (Sweden)

Ankica Rađenović

2013-01-01

Full Text Available A promising type of steel slag for applications is the ladle furnace (LF slag, which is also known as the basic slag, the reducing slag, the white slag, and the secondary refining slag. The LF slag is a byproduct from further refining molten steel after coming out of a basic oxygen furnace (BOF or an electric arc furnace (EAF. The use of the LF slag in further applications requires knowledge of its characteristics. The LF slag characterization in this paper has been performed using the following analytical methods: chemical analysis by energy dispersive spectrometry (EDS, mineralogical composition by X-ray diffraction (XRD, surface area properties by the Brunauer-Emmett-Teller (BET and the Barrett-Joyner-Halenda (BJH methods, surface chemistry by infrared absorption (FTIR spectroscopy, and morphological analysis by scanning electron microscopy (SEM. The results showed that the main compounds are calcium, silicon, magnesium, and aluminium oxides, and calcium silicates under their various allotropic forms are the major compounds in the LF slag. Surface area properties have shown that the LF slag is a mesoporous material with relatively great BET surface area. The ladle furnace slag is a nonhazardous industrial waste because the ecotoxicity evaluation by its eluate has shown that the LF slag does not contain constituents which might in any way affect the environment harmfully.

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

US State Submerged Lands

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Submerged Lands Act (43 U.S.C. Section 1301 et seq.) grants coastal states title to natural resources located within their coastal submerged lands and navigable...

Arc melting in inert gas atmosphere of zirconium sponge

International Nuclear Information System (INIS)

Julio Junior, O.; Andrade, A.H.P. de

1991-01-01

The obtainment of metallic zirconium in laboratory scale with commercial and nuclear quality is the objective of the Metallurgy Department of IEN/CNEN - Brazil, so a melting procedure of zirconium sponge in laboratory scale using an arc furnace in inert atmosphere is developed. The effects of atmosphere operation, and the use of gas absorber and the sponge characteristics over the quality of button in as-cast reporting with hardness measures are described. (C.G.C.)

CFD Modeling of Swirl and Nonswirl Gas Injections into Liquid Baths Using Top Submerged Lances

Science.gov (United States)

Huda, Nazmul; Naser, J.; Brooks, G.; Reuter, M. A.; Matusewicz, R. W.

2010-02-01

Fluid flow phenomena in a cylindrical bath stirred by a top submerged lance (TSL) gas injection was investigated by using the computational fluid dynamic (CFD) modeling technique for an isothermal air-water system. The multiphase flow simulation, based on the Euler-Euler approach, elucidated the effect of swirl and nonswirl flow inside the bath. The effects of the lance submergence level and the air flow rate also were investigated. The simulation results for the velocity fields and the generation of turbulence in the bath were validated against existing experimental data from the previous water model experimental study by Morsi et al.[1] The model was extended to measure the degree of the splash generation for different liquid densities at certain heights above the free surface. The simulation results showed that the two-thirds lance submergence level provided better mixing and high liquid velocities for the generation of turbulence inside the water bath. However, it is also responsible for generating more splashes in the bath compared with the one-third lance submergence level. An approach generally used by heating, ventilation, and air conditioning (HVAC) system simulations was applied to predict the convective mixing phenomena. The simulation results for the air-water system showed that mean convective mixing for swirl flow is more than twice than that of nonswirl in close proximity to the lance. A semiempirical equation was proposed from the results of the present simulation to measure the vertical penetration distance of the air jet injected through the annulus of the lance in the cylindrical vessel of the model, which can be expressed as L_{va} = 0.275( {do - di } )Frm^{0.4745} . More work still needs to be done to predict the detail process kinetics in a real furnace by considering nonisothermal high-temperature systems with chemical reactions.

Volatilization and redox testing in a DC arc melter: FY-93 and FY-94

International Nuclear Information System (INIS)

Grandy, J.D.; Sears, J.W.; Soelberg, N.R.; Reimann, G.A.; McIlwain, M.E.

1996-07-01

The purpose of these experiments was to study the dissolution, retention, volatilization, and trapping of transuranic radionuclide elements (TRUs), mixed fission and activation products, and high vapor pressure metals (HVPMS) during processing in a high temperature arc furnace. In all cases, surrogate elements (lanthanides) were used in place of radioactive ones. The experiments were conducted utilizing a small DC arc melter developed at the Idaho National Engineering Laboratory (INEL) Research Center (IRC). The small arc melter was originally developed in 1992 and has been used previously for waste form studies of iron enriched basalt (IEB) and IEB with zirconium and titanium additions (IEB4). Section 3 contains a description of the small arc melter and its operational capabilities are discussed in Chapter 4. The remainder of the document describes each testing program and then discusses results and findings

Metallurgy of mercury in Almaden: from aludel furnaces until Pacific furnaces

International Nuclear Information System (INIS)

Tejero-Manzanares, J.; Garrido Saenz, I.; Mata Cabrera, F.; Rubio Mesas, M. L.

2014-01-01

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)

A new multi-purpose furnace for the preparation of compounds, alloys and single crystals

International Nuclear Information System (INIS)

Spirlet, J.-C.; Wellum, R.

2004-01-01

A new modular multi-purpose furnace has been designed and the prototype constructed. This furnace was a development utilizing more than two decades of experience at the JRC establishment, Karlsruhe, to bring together the possibility of several techniques that normally require separate, expensive facilities. With this new modular device, different functions are provided by exchanging the head of the furnace while leaving the base as a permanent fixture. The processes can be carried out in high vacuum (10 -6 Pa) or in the presence of high-purity gases, e.g., argon. The modules developed allow the following processes to be carried out: Arc melting, levitation melting, resistance and radio-frequency heating in a crucible, single-crystal growth by various techniques, and electron-beam heating. The rationale behind the development was to produce a device capable of many functions but at an acceptable cost so as to make the various techniques available to a wide range of research and development institutes. A full description of the apparatus is given, outlining the range of the methods which can be applied to the production of high-purity advanced materials for research purposes

Advanced steel reheat furnace

Energy Technology Data Exchange (ETDEWEB)

Moyeda, D.; Sheldon, M.; Koppang, R. [Energy and Environmental Research Corp., Irvine, CA (United States); Lanyi, M.; Li, X.; Eleazer, B. [Air Products and Chemicals, Inc., Allentown, PA (United States)

1997-10-01

Energy and Environmental Research Corp. (EER) under a contract from the Department of Energy is pursuing the development and demonstration of an Advanced Steel Reheating Furnace. This paper reports the results of Phase 1, Research, which has evaluated an advanced furnace concept incorporating two proven and commercialized technologies previously applied to other high temperature combustion applications: EER`s gas reburn technology (GR) for post combustion NOx control; and Air Product`s oxy-fuel enrichment air (OEA) for improved flame heat transfer in the heating zones of the furnace. The combined technologies feature greater production throughput with associated furnace efficiency improvements; lowered NOx emissions; and better control over the furnace atmosphere, whether oxidizing or reducing, leading to better control over surface finish.

Submerged Grove in Lake Onogawa

OpenAIRE

Sato, Yasuhiro; Nakamura, Soken; Ochiai, Masahiro

1996-01-01

Abstract : The first record by ultrasonic echo sounding on the distribution of the submerged standing trees on the bottom of Lake Onogawa is presented. Lake Onogawa is a dammed lake formed at the time of the eruption of the volcano Mt.Bandai in 1888. Since then the original vegetation of the dammed valley has remained submerged. Many submerged standing trees are distributed on the bottom within about 600m from the northeast end of the lake. The density of the trees in this area is sufficient ...

Experimental study of metal nanoparticle synthesis by an arc evaporation/condensation process

International Nuclear Information System (INIS)

Förster, Henning; Wolfrum, Christian; Peukert, Wolfgang

2012-01-01

The generation of copper nanoparticles in an arc furnace by the evaporation/condensation method is systematically investigated. The evaporation/condensation process is advantageous because it allows direct synthesis using pure metals as starting materials avoiding reactions of expensive and potentially poisonous precursors. In the presented system, a transferred direct current arc provides the energy for evaporation of the metal target. In order to prevent an oxidation of the particles in the process, the synthesis is conducted in an atmosphere of inert gases (purity grade 5.0). The arc stability and its effect on particle synthesis are investigated. The experiments reveal excellent long-term arc stability for at least 8 h continuous operation delivering aerosols with high reproducibility (±10 % of average particle size). The influences of the arc current and length, the flow rates of the applied gases and the injection of hydrogen in the plasma zone on the particle size distributions and the agglomerate structure are studied. The produced copper nanoparticles are characterized by scanning mobility particle sizing and scanning electron microscopy. The average particle size could be well controlled in a size range 4–50 nm by selecting appropriate operating parameters.

Optimization of submerged vane parameters

Indian Academy of Sciences (India)

H Sharma

the height or length of the submerged vane, no effective change in bed profile .... easily and again vanes will be ineffective, which is what. Odgaard and .... [3] Odgaard A J and Wang Y 1991a Sediment management with submerged vanes.

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.

Comparison of a burning mass ceramics coating in laboratory furnace and instrustrial furnace

International Nuclear Information System (INIS)

Soares, R.A.L.; Castro, J.R. de S.

2012-01-01

This work intends to analyze the differences obtained in the technological properties of a ceramic coating after firing in two distinct environments, laboratory furnace and industrial furnace. For this, was characterized a ceramic mass used in the production of porous coating. The analyzes were performed chemical, mineralogical and thermal mass in that. The specimens were obtained by compacting and burned in the maximum temperature of 1140 deg C in two furnaces, laboratory and industrial. The technological tests were performed linear shrinkage, water absorption, bulk density and mechanical strength. The microstructure was evaluated by ray-X diffraction and scanning electron microscopy. The results showed that both furnaces provided significant differences in analyzed specimens, such as increased strength and low water absorption in the fired samples in a laboratory furnace, for example. (author)

Acoustic and adsorption properties of submerged wood

Science.gov (United States)

Hilde, Calvin Patrick

Wood is a common material for the manufacture of many products. Submerged wood, in particular, is used in niche markets, such as the creation of musical instruments. An initial study performed on submerged wood from Ootsa Lake, British Columbia, provided results that showed that the wood was not suitable for musical instruments. This thesis re-examined the submerged wood samples. After allowing the wood to age unabated in a laboratory setting, the wood was retested under the hypothesis that the physical acoustic characteristics would improve. It was shown, however, that the acoustic properties became less adequate after being left to sit. The adsorption properties of the submerged wood were examined to show that the submerged wood had a larger accessible area of wood than that of control wood samples. This implied a lower amount of crystalline area within the submerged wood. From the combined adsorption and acoustic data for the submerged wood, relationships between the moisture content and speed of sound were created and combined with previous research to create a proposed model to describe how the speed of sound varies with temperature, moisture content and the moisture content corresponding to complete hydration of sorption sites within the wood.

Irradiated dynamic fracture toughness of ASTM A533, Grade B, Class 1 steel plate and submerged arc weldment. Heavy section steel technology program technical report No. 41

International Nuclear Information System (INIS)

Davidson, J.A.; Ceschini, L.J.; Shogan, R.P.; Rao, G.V.

1976-10-01

As a result of the Heavy Section Steel Technology Program (HSST), sponsored by the Nuclear Regulatory Commission, Westinghouse Electric Corporation conducted dynamic fracture toughness tests on irradiated HSST Plate 02 and submerged arc weldment material. Testing performed at the Westinghouse Research and Development Laboratory in Pittsburgh, Pennsylvania, included 0.394T compact tension, 1.9T compact tension, and 4T compact tension specimens. This data showed that, in the transition region, dynamic test procedures resulted in lower (compared to static) fracture toughness results, and that weak direction (WR) oriented specimen data were lower than the strong direction (RW) oriented specimen results. Irradiated lower-bound fracture toughness results of the HSST Program material were well above the adjusted ASME Section III K/sub IR/ curve. An irradiated and nonirradiated 4T-CT specimen was tested during a fracture toughness test as a preliminary study to determine the effect of irradiation on the acoustic emission-stress intensity factor relation in pressure vessel grade steel. The results indicated higher levels of acoustic emission activity from the irradiated sample as compared to the unirradiated one at a given stress intensity factor (K) level

Fluid-structure interaction of submerged structures

International Nuclear Information System (INIS)

Tang, H.T.; Becker, E.B.; Taylor, L.M.

1979-01-01

The purpose of the paper is to investigate fluid-structure interaction (FSI) of submerged structures in a confined fluid-structure system. Our particular interest is the load experienced by a rigid submerged structure subject to a pressure excitation in a fluid domain bounded by a structure which is either flexible or rigid. The objective is to see whether the load experienced by the submerged structure will be influenced by its confinement conditions. This investigation is intended to provide insight into the characteristics of FSI and answer the question as to whether one can obtain FSI independent data by constructing a small scale rigid submerged structure inside a flexible fluid-structure system. (orig.)

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)

Oxygen dynamics in submerged rice (Oryza sativa L.)

DEFF Research Database (Denmark)

Colmer, Timothy D.; Pedersen, Ole

2008-01-01

Complete submergence of plants prevents direct O2 and CO2 exchange with air. Underwater photosynthesis can result in marked diurnal changes in O2 supply to submerged plants. Dynamics in pO2 had not been measured directly for submerged rice (Oryza sativa), but in an earlier study, radial O2 loss...... from roots showed an initial peak following shoot illumination.  O2 dynamics in shoots and roots of submerged rice were monitored during light and dark periods, using O2 microelectrodes. Tissue sugar concentrations were also measured.  On illumination of shoots of submerged rice, pO2 increased rapidly...... of magnitude higher than in darkness, enhancing also pO2 in roots.The initial peak in pO2 following illumination of submerged rice was likely to result from high initial rates of net photosynthesis, fuelled by CO2 accumulated during the dark period. Nevertheless, since sugars decline with time in submerged...

Advanced characterization techniques in understanding the roles of nickel in enhancing strength and toughness of submerged arc welding high strength low alloy steel multiple pass welds in the as-welded condition

Science.gov (United States)

Sham, Kin-Ling

Striving for higher strength along with higher toughness is a constant goal in material properties. Even though nickel is known as an effective alloying element in improving the resistance of a steel to impact fracture, it is not fully understood how nickel enhances toughness. It was the goal of this work to assist and further the understanding of how nickel enhanced toughness and maintained strength in particular for high strength low alloy (HSLA) steel submerged arc welding multiple pass welds in the as-welded condition. Using advanced analytical techniques such as electron backscatter diffraction, x-ray diffraction, electron microprobe, differential scanning calorimetry, and thermodynamic modeling software, the effect of nickel was studied with nickel varying from one to five wt. pct. in increments of one wt. pct. in a specific HSLA steel submerged arc welding multiple pass weldment. The test matrix of five different nickel compositions in the as-welded and stress-relieved condition was to meet the targeted mechanical properties with a yield strength greater than or equal to 85 ksi, a ultimate tensile strength greater than or equal to 105 ksi, and a nil ductility temperature less than or equal to -140 degrees F. Mechanical testing demonstrated that nickel content of three wt. pct and greater in the as-welded condition fulfilled the targeted mechanical properties. Therefore, one, three, and five wt. pct. nickel in the as-welded condition was further studied to determine the effect of nickel on primary solidification mode, nickel solute segregation, dendrite thickness, phase transformation temperatures, effective ferrite grain size, dislocation density and strain, grain misorientation distribution, and precipitates. From one to five wt. pct nickel content in the as-welded condition, the primary solidification was shown to change from primary delta-ferrite to primary austenite. The nickel partitioning coefficient increased and dendrite/cellular thickness was

Presentation of the Vulcano installation which uses a plasma transferred arc rotary furnace for corium melting; Utilisation d`un four tournant a arc plasma transfere pour fondre et couler des melanges d`oxydes autour de 2000 C. Presentation du film Vulcano

Energy Technology Data Exchange (ETDEWEB)

Cognet, G.; Laffont, G.; Jegou, C.; Pierre, J.; Journeau, C.; Sudreau, F.; Roubaud, A. [CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. d`Etudes des Reacteurs

1998-06-01

In the case of loss coolant accident, the reactor core could melt and turn into a mixture of uranium oxides, zirconium, iron and steel called corium. A large experimental program has been launched to study corium behaviour, to qualify solutions to stabilize it and to confine it in the reactor containment. The Vulcano installation has been designed to that purpose. It is made up of: i) a plasma transferred arc rotary furnace, ii) a testing surface covered with refractory materials, iii) an induction heating system in order to simulate the residual power of corium, iv) instrumentation devices such as video cameras, thermocouples, infra-red pyrometers and flowmeters, and v) a laboratory to perform chemical analysis of corium samples. The first experimental results show that a mixture of corium and concrete spreads better than expected. It seems that a low initial height of matter can produce a great distance flowing while having a chaotic behaviour. This characteristic suggests that the mixture acts as a Bingham type threshold fluid. (A.C.) 5 refs.

Impeller Submergence Depth for Stirred Tanks

Directory of Open Access Journals (Sweden)

Thiyam T. Devi

2011-11-01

Full Text Available Impeller submergence governs the performance of mixing tanks employed in oxygen transfer operation. Present work experimentally investigates the effect of impeller submergence depths on oxygen transfer and corresponding power consumption. It has been found that at higher range of impeller submergence, mixing tanks consume less power and gives higher values of oxygen transfer coefficient. Optimal range of submergence depth is 0.7 to 0.9 times the impeller diameter. Copyright ©2011 BCREC UNDIP. All rights reserved.(Received: 4th March 2011; Revised: 12nd July 2011; Accepted: 14th July 2011[How to Cite: T.T. Devi, A.P. Sinha, M. Thakre, and B. Kumar. (2011. Impeller Submergence Depth for Stirred Tanks. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 123-128. doi:10.9767/bcrec.6.2.826.123-128][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.826.123-128 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/826] | View in 

Plasma arc pyrolysis of radioactive ion exchange resin

International Nuclear Information System (INIS)

Pickles, C.A.; Toguri, J.M.

1992-01-01

This paper reports on two ion exchange resins (IRN 77 and IRN 78) which were pyrolysed in a plasma-arc furnace. Both continuous and batch tests were performed. Volume reduction ratios of 10 to 1 and 10 to 3.5 were achieved for IRN 78 and IRN 77 respectively. The product of the resin pyrolysis was a char which contained the radioactive elements such as cobalt. The off-gases consisted of mainly hydrogen and carbon monoxide. There was a relatively small amount of dust in the off-gases. At the present time radioactive ion exchange resign is being kept in storage. The volume of this waste is increasing and it is important that the volume be reduce. The volume reduction ratio should be of the order of ten-to-one. Also, it is required that the radioactive elements can be collected or fixed in a form which could easily be disposed of. Plasma arc treatment offers considerable potential for the processing of the waste

Drought and submergence tolerance in plants

Energy Technology Data Exchange (ETDEWEB)

Du, Hewei; Zhou, Yufan; Oksenberg, Nir; Ronald, Pamela

2017-11-14

The invention provides methods of genetically modified plants to increase tolerance to drought and/or submergence. The invention additionally provides plants having increased drought and/or submergence tolerance engineered using such methods.

IODINE REMOVAL EFFICIENCY IN NON-SUBMERGED AND SUBMERGED SELF-PRIMING VENTURI SCRUBBER

OpenAIRE

MAJID ALI; YAN CHANGQI; SUN ZHONGNING; GU HAIFENG; WANG JUNLONG; KHURRAM MEHBOOB

2013-01-01

The objective of this conducted research is to study the iodine removal efficiency in a self-priming venturi scrubber for submerged and non-submerged operating conditions experimentally and theoretically. The alkaline solution is used as an absorbent, which is prepared by dissolving sodium hydroxide (NaOH) and sodium thiosulphate (Na2S2O3) in water to remove the gaseous iodine (I2) from the gas. Iodine removal efficiency is examined at various gas flow rates and inlet concentrations of iodine...

Furnace

Energy Technology Data Exchange (ETDEWEB)

Osintsev, V V; Khidiyatov, A M

1981-01-01

The purpose of the invention is to improve the operating efficiency of the furnace device containing prefurnaces connected to the main combustion chamber. For this purpose in the proposed furnace device is equipped with prefurnaces with burners, rectangular vertical chamber of combustion is equipped with central hearth projection. As indicated by studies, the hearth projection of the indicated projections promotes the development of transverse streams which guarantee effective mixing of the combustion products in the upper part of the combustion chamber 3. This reduces the nonuniformity of temperature at the outlet from the latter, decreases the probability of slagging and hot spots on the heating surface.

Submerged membrane distillation for desalination of water

KAUST Repository

Francis, Lijo; Ghaffour, NorEddine; Alsaadi, Ahmad Salem

2016-01-01

Submerged membrane modules for use for desalination of water are disclosed. In one or more aspects, the membrane modules can be submerged either in a feed solution tank or the feed solution can pass through the lumen side of the membrane submerged within the tank. The feed solution can be a water-based feed stream containing an amount of salt.

Submerged membrane distillation for desalination of water

KAUST Repository

Francis, Lijo

2016-10-27

Submerged membrane modules for use for desalination of water are disclosed. In one or more aspects, the membrane modules can be submerged either in a feed solution tank or the feed solution can pass through the lumen side of the membrane submerged within the tank. The feed solution can be a water-based feed stream containing an amount of salt.

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.

Simulation of Radiation Heat Transfer in a VAR Furnace Using an Electrical Resistance Network

Science.gov (United States)

Ballantyne, A. Stewart

The use of electrical resistance networks to simulate heat transfer is a well known analytical technique that greatly simplifies the solution of radiation heat transfer problems. In a VAR furnace, radiative heat transfer occurs between the ingot, electrode, and crucible wall; and the arc when the latter is present during melting. To explore the relative heat exchange between these elements, a resistive network model was developed to simulate the heat exchange between the electrode, ingot, and crucible with and without the presence of an arc. This model was then combined with an ingot model to simulate the VAR process and permit a comparison between calculated and observed results during steady state melting. Results from simulations of a variety of alloys of different sizes have demonstrated the validity of the model. Subsequent simulations demonstrate the application of the model to the optimization of both steady state and hot top melt practices, and raises questions concerning heat flux assumptions at the ingot top surface.

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.

Industrial furnace with improved heat transfer

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, M.; Lingle, T.M.

1992-07-07

This patent describes an industrial furnace for heating work which emits volatiles during heating. It comprises a generally cylindrical, closed end furnace section defining a sealable heat transfer chamber for heating work disposed therein; fan means for directing furnace atmosphere as a swirling wind mass about the interior of the furnace section over a portion thereof; heat means for heating the wind mass within the fan chamber; and an incineration track formed as a circumferentially extending groove about the exterior of the furnace section and in heat transfer relationship with and situated at least to extend about a portion of the fan chamber.

Automated, High Temperature Furnace for Glovebox Operation

International Nuclear Information System (INIS)

Neikirk, K.

2001-01-01

The Plutonium Immobilization Project (PIP), to be located at the Savannah River Site SRS, is a combined development and testing effort by Lawrence Livermore National Laboratory (LLNL), Westinghouse Savannah River Company (WSRC), Pacific Northwest National Laboratory (PNNL), Argonne National Laboratory (ANL), and the Australian National Science and Technology Organization (ANSTO). The Plutonium Immobilization process involves the disposition of excess plutonium by incorporation into ceramic pucks. As part of the immobilization process, furnaces are needed for sintering the ceramic pucks. The furnace being developed for puck sintering is an automated, bottom loaded furnace with insulating package and resistance heating elements located within a nuclear glovebox. Other furnaces types considered for the application include retort furnaces and pusher furnaces. This paper, in part, will discuss the furnace technologies considered and furnace technology selected to support reliable puck sintering in a glovebox environment

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

Irradiation behavior of a submerged arc welding material with different copper content; Bestrahlungsverhalten einer UP-Versuchsschweissnaht mit unterschiedlichen Kupfergehalten

Energy Technology Data Exchange (ETDEWEB)

Langer, R [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Bartsch, R [Kernkraftwerk Obrigheim GmbH (Germany)

1998-11-01

Che report presents results of an irradiation program on specimens of submerged arc weldings with copper contents of 0.14% up to 0.42% and a fluence up to 2.2E19 cm{sup -2} (E>1MeV). Unirradiated and irradiated tensile- Charpy-, K{sub lc}- and Pellini-specimens were tested of material with a copper content of 0.22%. On the other materials Charpy tests and tensile tests were performed. The irradiation of the specimens took place in the KWO - ``RPV, a PWR with low flux and in the VAK - RPV, a small BWR with high flux. - The irradiation induced embrittlemnt shows a copper dependence up to about 30%. The specimens with a copper content higher than 0.30% show no further embrittlement. Irradiation in different reactors with different flux (factor > 33) shows the same state of embrittlement. Determination of a K{sub lc}, T-curve with irradiated specimens is possible. The conservative of the RT{sub NDT} - concept could be confirmed by the results of Charpy-V, drop weight- and K{sub lc}-test results. [Deutsch] Zur zusaetzlichen Absicherung des KWO-RDB wurde Ende 1979 eine UP-Versuchsschweissnaht mit vergleichbarer chemischer Zusammensetzung und vergleibaren mechanisch-technologischen Werkstoffen im unbestrahlten Ausgangszustand wie die RDB Core-Rundnaht hergestellt. Teile der Naht wurden durch Verkupfern der Schweissdraehte auf unterschiedliche Gehalte von Cu=0,14% bis 0,42% eingestellt. Aus dieser Schweissverbindung wurden Proben im VAK und KWO-RDB bestrahlt. Im Rahmen der Aktivitaeten zur Absicherung des KWO-RDBs erfolgte 1995 die Pruefung der bestrahlten Proben. Die mechanisch technologischen Werkstoffwerte vor und nach Bestrahlung werden gegenuebergestellt und praesentiert. Mit dem Ergebnis wurde ein weiterer Nachweis fuer die Konservativitaet des RT{sub NDT}-Konzeptes erbracht. Es wurde nachgewiesen, dass fuer den untersuchten Bereich kein Dose-Rate Effekt bzw. Bestrahlungszeiteinfluss existiert. Fuer UP-Schweissungen mit den vorliegenden Fertigungsparametern und bei

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

EFFICIENT USE OF ENERGY IN A ELECTRIC ARC FURNANCE BY HEAT INTEGRATION APPROACH

OpenAIRE

Umesh Kumar, Dr. A K Prasad, Sourabh Kumar Soni

2016-01-01

Based on the principles of heat integration, the present work investigates the design and operational modifications which can lead to efficient energy integration in an electric arc furnace being operated with direct reduction process. This process is one of the oldest and most widely applied processes amongst the commercially used process in India. For the purpose of energy integration stream data is extracted from the actual flow sheet of the plant, which consists of supply and target tempe...

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. Copyright © 2014 Elsevier B.V. All rights reserved.

[Utilization of a transferred arc-plasma rotating furnace to melt and found oxide mixtures at around 2000 degrees C (presentation of the film VULCANO)].

Science.gov (United States)

Cognet, G; Laffont, G; Jegou, C; Pierre, J; Journeau, C; Sudreau, F; Roubaud, A

1999-03-01

Unless security measures are taken, a hypothetical accident resulting from the loss of the cooling circuit in a pressurized water nuclear reactor could cause the heart of the reactor to melt forming a bath, called the corium, mainly composed of uranium, zirconium and iron oxides as well as the structural steel. This type of situation would be similar to the Three Mile Island accident in 1979. In order to limit the consequences of such an accident, the Atomic Energy Commission has implemented a large study program [1] to improve our understanding of corium behavior and determine solutions to stabilize it and avoid its propagation outside the unit. The VULCANO installation was designed in order to perform the trials using real materials which are indispensable to study all the phenomena involved. A film on the VULCANO trials was presented at the Henri Moissan commemorative session organized by the French National Academy of Pharmacy. The rotating furnace used to melt and found the mixture simulating the corium is a direct descendant of the pioneer work by Henri Moissan. An electrical arc is directed at the center of the load to melt which is maintained against the walls by centrifugal force. After six high-temperature trials performed with compositions without uranium oxide, the first trial with real corium showed that the magma spread rather well, a result which is quite favorable for cooling.

Study on the Fluid Flow Characteristics of Coherent Jets with CO2 and O2 Mixed Injection in Electric Arc Furnace Steelmaking Processes

Science.gov (United States)

Wei, Guangsheng; Zhu, Rong; Wu, Xuetao; Yang, Lingzhi; Dong, Kai; Cheng, Ting; Tang, Tianping

2018-06-01

As an efficient oxygen supplying technology, coherent jets are widely applied in electric arc furnace (EAF) steelmaking processes to strengthen chemical energy input, speed up smelting rhythm, and promote the uniformity of molten bath temperature and compositions. Recently, the coherent jet with CO2 and O2 mixed injection (COMI) was proposed and demonstrated great application potentiality in reducing the dust production in EAF steelmaking. In the present study, based on the eddy dissipation concept model, a computational fluid dynamics model of coherent jets with COMI was built with the overall and detailed chemical kinetic mechanisms (GRI-Mech 3.0). Compared with one-step combustion reaction, GRI-Mech 3.0 consists of 325 elementary reactions with 53 components and can predict more accurate results. The numerical simulation results were validated by the combustion experiment data. The jet behavior and the fluid flow characteristics of coherent jets with COMI under 298 K and 1700 K (25 °C and 1427 °C) were studied and the results showed that for coherent jets with COMI, the chemical effect of CO2 significantly weakened the shrouding combustion reactions of CH4 and the relative importance of the chemical effect of CO2 increases with CO2 concentration increasing. The potential core length of coherent jet decreases with the volume fraction of CO2 increasing. Moreover, it also can be found that the potential core length of coherent jets was prolonged with higher ambient temperature.

Study on the Fluid Flow Characteristics of Coherent Jets with CO2 and O2 Mixed Injection in Electric Arc Furnace Steelmaking Processes

Science.gov (United States)

Wei, Guangsheng; Zhu, Rong; Wu, Xuetao; Yang, Lingzhi; Dong, Kai; Cheng, Ting; Tang, Tianping

2018-03-01

As an efficient oxygen supplying technology, coherent jets are widely applied in electric arc furnace (EAF) steelmaking processes to strengthen chemical energy input, speed up smelting rhythm, and promote the uniformity of molten bath temperature and compositions. Recently, the coherent jet with CO2 and O2 mixed injection (COMI) was proposed and demonstrated great application potentiality in reducing the dust production in EAF steelmaking. In the present study, based on the eddy dissipation concept model, a computational fluid dynamics model of coherent jets with COMI was built with the overall and detailed chemical kinetic mechanisms (GRI-Mech 3.0). Compared with one-step combustion reaction, GRI-Mech 3.0 consists of 325 elementary reactions with 53 components and can predict more accurate results. The numerical simulation results were validated by the combustion experiment data. The jet behavior and the fluid flow characteristics of coherent jets with COMI under 298 K and 1700 K (25 °C and 1427 °C) were studied and the results showed that for coherent jets with COMI, the chemical effect of CO2 significantly weakened the shrouding combustion reactions of CH4 and the relative importance of the chemical effect of CO2 increases with CO2 concentration increasing. The potential core length of coherent jet decreases with the volume fraction of CO2 increasing. Moreover, it also can be found that the potential core length of coherent jets was prolonged with higher ambient temperature.

Automated, High Temperature Furnace for Glovebox Operation

International Nuclear Information System (INIS)

Neikirk, K.

2001-01-01

The U.S. Department of Energy will immobilize excess plutonium in the proposed Plutonium Immobilization Plant (PIP) at the Savannah River Site (SRS) as part of a two track approach for the disposition of weapons usable plutonium. As such, the Department of Energy is funding a development and testing effort for the PIP. This effort is being performed jointly by Lawrence Livermore National Laboratory (LLNL), Westinghouse Savannah River Company (WSRC), Pacific Northwest National Laboratory (PNNL), and Argonne National Laboratory (ANL). The Plutonium Immobilization process involves the disposition of excess plutonium by incorporation into ceramic pucks. As part of the immobilization process, furnaces are needed for sintering the ceramic pucks. The furnace being developed for puck sintering is an automated, bottom loaded furnace with insulting package and resistance heating elements located within a nuclear glovebox. Other furnaces considered for the application include retort furnaces and pusher furnaces. This paper, in part, will discuss the furnace technologies considered and furnace technology selected to support reliable puck sintering in a glovebox environment. Due to the radiation levels and contamination associated with the plutonium material, the sintering process will be fully automated and contained within nuclear material gloveboxes. As such, the furnace currently under development incorporates water and air cooling to minimize heat load to the glovebox. This paper will describe the furnace equipment and systems needed to employ a fully automated puck sintering process within nuclear gloveboxes as part of the Plutonium Immobilization Plant

Study of electric arc welding of castings for nuclear power machine-building

International Nuclear Information System (INIS)

Rymkevich, A.I.; Korsunov, P.M.

1977-01-01

Mechanical and corrosion-resistance properties are studied of the welded joints of cast billets from steel 00Kh12N3DL by automatic submerged arc welding. It is shown by testing the joints made with preheating up to 100 deg C and subsequent tempering (620 deg C for 25 h + 640 deg C for 16 h) that in the temperature range of 20-350 deg C they possess fairly good strength, ductility, impact viscosity, and corrosion-resistance properties approximating the corresponding characteristics of the base metal. The welding technology developed can be used to make pump casings for atomic power equipment

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,

Submergence tolerance in Hordeum marinum

DEFF Research Database (Denmark)

Pedersen, Ole; Malik, Al I.; Colmer, Timothy D.

2010-01-01

Floodwaters differ markedly in dissolved CO(2), yet the effects of CO(2) on submergence responses of terrestrial plants have rarely been examined. The influence of dissolved CO(2) on underwater photosynthesis and growth was evaluated for three accessions of the wetland plant Hordeum marinum Huds....... All three accessions tolerated complete submergence, but only when in CO(2) enriched floodwater. Plants submerged for 7 days in water at air equilibrium (18 mM CO(2)) suffered loss of biomass, whereas those with 200 mM CO(2) continued to grow. Higher underwater net photosynthesis at 200 mM CO(2......) increased by 2.7- to 3.2-fold sugar concentrations in roots of submerged plants, compared with at air equilibrium CO(2). Leaf gas films enhancing gas exchange with floodwater, lack of a shoot elongation response conserving tissue sugars and high tissue porosity (24-31% in roots) facilitating internal O(2...

Submerged cutting characteristics of abrasive suspension jet

International Nuclear Information System (INIS)

Shimizu, Seiji; Peng, Guoyi; Oguma, Yasuyuki; Nishikata, Hiroyuki

2015-01-01

An abrasive suspension jet (ASJ) formed by propelling abrasive suspension through a nozzle has a greater cutting capability than the conventional abrasive water jet. However the cutting capability of submerged ASJs decreases drastically with increasing the standoff distance and the pressure around the jet. A sheathed nozzle with ventilation for ASJs has been developed as a mean of extending the effective stand-off distance and improving the cutting capabilities under submerged condition. In the present investigation, cutting tests by ASJs in air and under submerged condition are conducted with specimens of aluminum alloy. Air coated ASJs are formed by using a sheathed nozzle with ventilation. The relative cutting depth is defined as the cutting depth under submerged condition divided by the cutting depth in air at the same standoff distance. The relative cutting depth is arranged effectually by the cavitation number based on the cavity pressure measured at the sheath. (author)

Behavior of coke in large blast furnaces

Energy Technology Data Exchange (ETDEWEB)

Nakamura, N

1978-01-01

Three blast furnaces were quenched in operation and the contents were examined; the temperature distribution was also measured, using Tempil pellets. The furnaces examined included a low productivity one, which was examined to see what was wrong. Changes in the quality of coke as it descends in the furnace, and coke behavior in the raceway and hearth are reported. The functions required of coke, and the effects of poor coke quality, are explained, together with the coke quality required in large blast furnaces. A theoretical study of the role of coke in large blast furnaces is included.

Effects of Surface Alloying and Laser Beam Treatment on the Microstructure and Wear Behaviour of Surfaces Modified Using Submerged Metal Arc Welding

Directory of Open Access Journals (Sweden)

Regita BENDIKIENE

2016-05-01

Full Text Available In this study, the effects of surface alloying of cheap plain carbon steel using submerged metal arc technique and subsequent laser beam treatment on the microstructure and wear behaviour of surfaced layers were studied. This method is the cheapest one to obtain high alloyed coatings, because there is no need to apply complex technologies of powder making (metal powder is spread on the surface of base metal or inserted into the flux, it is enough to grind, granulate and blend additional materials. On the other hand, strengthening of superficial layers of alloys by thermal laser radiation is one of the applications of laser. Surface is strengthened by concentrated laser beam focused into teeny area (from section of mm till some mm. Teeny area of metal heat up rapidly and when heat is drain to the inner metal layers giving strengthening effect. Steel surface during this treatment exceeds critical temperatures, if there is a need to strengthen deeper portions of the base metal it is possible even to fuse superficial layer. The results presented in this paper are based on micro-structural and micro-chemical analyses of the surfaced and laser beam treated surfaces and are supported by analyses of the hardness, the wear resistance and resultant microstructures. Due to the usage of waste raw materials a significant improvement (~ 30 % in wear resistance was achieved. The maximum achieved hardness of surfaced layer was 62 HRC, it can be compared with high alloyed conventional steel grade. Wear properties of overlays with additional laser beam treatment showed that weight loss of these layers was ~10 % lower compared with overlays after welding; consequently it is possible to replace high alloyed conventional steel grades forming new surfaces or restoring worn machine elements and tools.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.7621

Multielement stoichiometry of submerged macrophytes across Yunnan plateau lakes (China).

Science.gov (United States)

Xing, Wei; Wu, Haoping; Shi, Qiao; Hao, Beibei; Liu, Han; Wang, Zhixiu; Liu, Guihua

2015-05-13

Stoichiometric homeostasis of element composition is one of the central concepts of ecological stoichiometry. We analyzed concentrations of macroelements (C, N, P, Ca, K, Mg, S), microelements (Cu, Fe, Mn, Mo, Ni, Zn) and beneficial elements (Na, Se, Si) in submerged macrophytes, water and sediments across 20 Yunnan plateau lakes. We predicted that tissue element composition in submerged macrophytes is affected by lake trophic level and taxonomy, and submerged macrophytes have weak stoichiometric homeostasis for all above 16 elements. Canonical discriminant analyses successfully discriminated among trophic level groups and taxa groups. Of all the elements, C, N, P and S most effectively discriminated among trophic level groups across 20 lakes, revealing lake trophic level mostly affect tissue macroelement composition in submerged macrophytes; while Ca, K and Se most effectively discriminated among submerged macrophytes taxa groups, suggesting taxonomy mostly affect compositions of macroelements and beneficial elements in submerged macrophytes. In addition, the stoichiometric homeostatic coefficient of 1/HCa:C for all five taxa of submerged macrophytes were less than zero, suggesting submerged macrophytes in Yunnan plateau lakes have strong Ca stoichiometric homeostasis. Our findings, not only broaden the knowledge of multielement stoichiometric homeostasis, but also help to choose most appropriate lake management strategy.

Technological Innovations of Carbon Dioxide Injection in EAF-LF Steelmaking

Science.gov (United States)

Wei, Guangsheng; Zhu, Rong; Wu, Xuetao; Dong, Kai; Yang, Lingzhi; Liu, Runzao

2018-06-01

In this study, the recent innovations and improvements in carbon dioxide (CO2) injection technologies for electric arc furnace (EAF)-ladle furnace (LF) steelmaking processes have been reviewed. The utilization of CO2 in the EAF-LF steelmaking process resulted in improved efficiency, purity and environmental impact. For example, coherent jets with CO2 and O2 mixed injection can reduce the amount of iron loss and dust generation, and submerged O2 and powder injection with CO2 in an EAF can increase the production efficiency and improve the dephosphorization and denitrification characteristics. Additionally, bottom-blowing CO2 in an EAF can strengthen molten bath stirring and improve nitrogen removal, while bottom-blowing CO2 in a LF can increase the rate of desulfurization and improve the removal of inclusions. Based on these innovations, a prospective process for the cyclic utilization of CO2 in the EAF-LF steelmaking process is introduced that is effective in mitigating greenhouse gas emissions from the steelmaking shop.

Technological Innovations of Carbon Dioxide Injection in EAF-LF Steelmaking

Science.gov (United States)

Wei, Guangsheng; Zhu, Rong; Wu, Xuetao; Dong, Kai; Yang, Lingzhi; Liu, Runzao

2018-03-01

In this study, the recent innovations and improvements in carbon dioxide (CO2) injection technologies for electric arc furnace (EAF)-ladle furnace (LF) steelmaking processes have been reviewed. The utilization of CO2 in the EAF-LF steelmaking process resulted in improved efficiency, purity and environmental impact. For example, coherent jets with CO2 and O2 mixed injection can reduce the amount of iron loss and dust generation, and submerged O2 and powder injection with CO2 in an EAF can increase the production efficiency and improve the dephosphorization and denitrification characteristics. Additionally, bottom-blowing CO2 in an EAF can strengthen molten bath stirring and improve nitrogen removal, while bottom-blowing CO2 in a LF can increase the rate of desulfurization and improve the removal of inclusions. Based on these innovations, a prospective process for the cyclic utilization of CO2 in the EAF-LF steelmaking process is introduced that is effective in mitigating greenhouse gas emissions from the steelmaking shop.

Utilización del polvo de acería de horno de arco eléctrico. // Use of powder produced by electric arc furnaces at steel plants.

Directory of Open Access Journals (Sweden)

D. Tápanes Robau

2001-01-01

Full Text Available El polvo de las Acerías de Horno de Arco Eléctrico se produce como consecuencia de la producción de Acero, durante ladepuración de los gases, y, en menor medida, en sus equipos de captación de aire. Estos polvos deben ser captados por lossistemas de depuración del taller. Con el presente trabajo pretendemos darle utilidad a un producto de desecho como es elpolvo, mejorar las condiciones ambientales en el taller, elevar la calidad del pavimento u hormigón asfáltico mediante lavariación de sus propiedades y disminuir el costo de la tonelada de acero mediante la comercialización de estos productosde desecho.Palabras claves: Polvos, aglutinantes, composición química, pruebas realizadas._______________________________________________________________________________SummaryThe powder generated by electric arc furnaces at steel plants is the result of processes such as the production of steel, thepurification of gases and, capturing air equipment .This article shows a method for recycling waste material – powder in this case- which also contributes to improve the steelplant environment, provides the possibility of improving asphalt paving and makes the production of steel cheaper throughthe commercialization of waste materials.Key words: Powder, binder, tests, chemical composition.

Refractory of Furnaces to Reduce Environmental Impact

International Nuclear Information System (INIS)

Hanzawa, Shigeru

2011-01-01

The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO 2 produced from this high energy load. To improve this situation, R and D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO 2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.

Refractory of Furnaces to Reduce Environmental Impact

Science.gov (United States)

Hanzawa, Shigeru

2011-10-01

The energy load of furnaces used in the manufacturing process of ceramics is quite large. Most of the environmental impact of ceramics manufacturing is due to the CO2 produced from this high energy load. To improve this situation, R&D has focused on furnace systems and techniques of control in order to reduce energy load. Since furnaces are comprised of refractory, consideration of their mechanical and thermal characteristics is important. Herein are described several refractory types which were chosen through comparison of the characteristics which contribute to heat capacity reduction, heat insulating reinforcement and high emissivity, thereby improving thermal radiation heat transfer efficiency to the ceramic articles. One selected refractory material which will reduce the environmental impact of a furnace, chosen considering low heat capacity and high emissivity characteristics, is SiC. In this study, thermal radiation heat transfer efficiency improvement and its effect on ceramic articles in the furnace and oxidation behaviour were investigated at 1700K. A high density SiC refractory, built into the furnace at construction, has relatively high oxidation durability and has the ability to reduce environmental impact-CO2 by 10 percent by decreasing the furnace's energy load. However, new oxidation prevention techniques for SiC will be necessary for long-term use in industrial furnaces, because passive to active oxidation transition behaviour of commercial SiC refractory is coming to close ideal.

Impeded Carbohydrate Metabolism in Rice Plants under Submergence Stress

Directory of Open Access Journals (Sweden)

Malay Kumar ADAK

2011-06-01

Full Text Available The detrimental effects of submergence on physiological performances of some rice varieties with special references to carbohydrate metabolisms and their allied enzymes during post-flowering stages have been documented and clarified in the present investigation. It was found that photosynthetic rate and concomitant translocation of sugars into the panicles were both related to the yield. The detrimental effects of the complete submergence were recorded in generation of sucrose, starch, sucrose phosphate synthase and phosphorylase activity in the developing panicles of the plants as compared to those under normal or control (i.e. non-submerged condition. The accumulation of starch was significantly lower in plants under submergence and that was correlated with ADP-glucose pyrophosphorylase activity. Photosynthetic rate was most affected under submergence in varying days of post-flowering and was also related to the down regulation of Ribulose bisphosphate carboxylase activity. However, under normal or control condition, there recorded a steady maintenance of photosynthetic rate at the post-flowering stages and significantly higher values of Ribulose bisphosphate carboxylase activity. Still, photosynthetic rate of the plants under both control and submerged conditions had hardly any significant correlation with sugar accumulation and other enzymes of carbohydrate metabolism like invertase with grain yield. Finally, plants under submergence suffered significant loss of yield by poor grain filling which was related to impeded carbohydrate metabolism in the tissues. It is evident that loss of yield under submergence is attributed both by lower sink size or sink capacity (number of panicles, in this case as well as subdued carbohydrate metabolism in plants and its subsequent partitioning into the grains.

Model based energy benchmarking for glass furnace

International Nuclear Information System (INIS)

Sardeshpande, Vishal; Gaitonde, U.N.; Banerjee, Rangan

2007-01-01

Energy benchmarking of processes is important for setting energy efficiency targets and planning energy management strategies. Most approaches used for energy benchmarking are based on statistical methods by comparing with a sample of existing plants. This paper presents a model based approach for benchmarking of energy intensive industrial processes and illustrates this approach for industrial glass furnaces. A simulation model for a glass furnace is developed using mass and energy balances, and heat loss equations for the different zones and empirical equations based on operating practices. The model is checked with field data from end fired industrial glass furnaces in India. The simulation model enables calculation of the energy performance of a given furnace design. The model results show the potential for improvement and the impact of different operating and design preferences on specific energy consumption. A case study for a 100 TPD end fired furnace is presented. An achievable minimum energy consumption of about 3830 kJ/kg is estimated for this furnace. The useful heat carried by glass is about 53% of the heat supplied by the fuel. Actual furnaces operating at these production scales have a potential for reduction in energy consumption of about 20-25%

Flow and scour around vertical submerged structures

Indian Academy of Sciences (India)

The safety of the foundations of submerged hydraulic structures due to excessive local scour is threatened by the erosive action of the waves and currents passing around these structures. Fish and aquatic habitat is seriously affected due to the modification of the flow field caused by these submerged structures. Hence, the ...

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.

Energy Saving in Industrial Annealing Furnaces

Directory of Open Access Journals (Sweden)

Fatma ÇANKA KILIÇ

2018-03-01

Full Text Available In this study, an energy efficiency studies have been carried out in a natural gas-fired rolling mill annealing furnace of an industrial establishment. In this context, exhaust gas from the furnace has been examined in terms of waste heat potential. In the examinations that have been made in detail; waste heat potential was found as 3.630,31 kW. Technical and feasibility studies have been carried out to realize electricity production through an Organic Rankine Cycle (ORC system for evaluating the waste heat potential of the annealing furnace. It has been calculated that 1.626.378,88 kWh/year of electricity can be generated by using the exhaust gas waste heat of the annealing furnace through an ORC system to produce electric energy with a net efficiency of 16%. The financial value of this energy was determined as 436.032,18 TL/year and the simple repayment period of the investment was 8,12 years. Since the annealing period of the annealing furnace is 2800 hours/year, the investment has not been found to be feasible in terms of the feasibility studies. However, the investment suitability can be assured when the annealing furnace is operating at full capacity for 8,000 hours or more annually.

Design and Development of Tilting Rotary Furnace

Science.gov (United States)

Sai Varun, V.; Tejesh, P.; Prashanth, B. N.

2018-02-01

Casting is the best and effective technique used for manufacturing products. The important accessory for casting is furnace. Furnace is used to melt the metal. A perfect furnace is one that reduces the wastage of material, reduces the cost of manufacturing and there by reduces the cost of production. Of all the present day furnaces there may be wastage of material, and the chances of increasing the time of manufacturing as the is continuous need of tilting of the furnace for every mould and then changing the moulds. Considering these aspects, a simple and least expensive tilting rotary furnace is designed and developed. The Tilting and Rotary Furnace consists of mainly melting chamber and the base. The metal enters the melting chamber through the input door that is provided on the top of the melting chamber. Inside the melting chamber there is a graphite furnace. The metal is melted in the graphite crucible. An insulation of ceramic fibre cloth is provided inside the furnace. The metal is melted using Propane gas. The propane gas is easily available and economic. The gas is burned using a pilot burner. The pilot burner is more efficient that other burners. The pilot burner is lit with a push button igniter. The pilot burner is located at the bottom of the combustion chamber. This enables the uniform heating of the metal inside the crucible. The temperature inside the melting chamber is noted using a temperature sensor. The gas input is cut-off if the temperature is exceeding a specific temperature. After the melting of the metal is done the furnace is tilted and after the mould is filled it is rotated. The external gears are used to controlling the tilting. The results of studies carried out for the design & development of low cost, simple furnace that can be mounted anywhere on the shop floor and this can be very much useful for the education purposes and small scale manufacturing. The furnace can be rotated in 360 degrees and can help in reducing the time taken

Preliminary Analysis of a Submerged Wave Energy Device

Science.gov (United States)

Wagner, J. R.; Wagner, J. J.; Hayatdavoodi, M.; Ertekin, R. C.

2016-02-01

Preliminary analysis of a submerged wave energy harvesting device is presented. The device is composed of a thin, horizontally submerged plate that is restricted to heave oscillations under the influence of surface waves. The submerged plate is oscillating, and it can be attached to a fixed rotor, or a piston, to harvest the wave energy. A fully submerged wave energy converter is preferred over a surface energy convertor due to its durability and less visual and physical distractions it presents. In this study, the device is subject to nonlinear shallow-water waves. Wave loads on the submerged oscillating plate are obtained via the Level I Green-Naghdi equations. The unsteady motion of the plate is obtained by solving the nonlinear equations of motion. The results are obtained for a range of waves with varying heights and periods. The amplitude and period of plate oscillations are analyzed as functions of the wave parameters and plate width. Particular attention is given to the selection of the site of desired wave field. Initial estimation on the amount of energy extraction from the device, located near shore at a given site, is provided.

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.

40 CFR 60.271a - Definitions.

Science.gov (United States)

2010-07-01

..., dampers, etc.) used to capture or transport particulate matter generated by an electric arc furnace or AOD... PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Steel Plants: Electric Arc Furnaces and... materials into the top of an electric arc furnace or the addition of molten steel or other materials into...

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.

Development of vacuum brazing furnace

International Nuclear Information System (INIS)

Singh, Rajvir; Yedle, Kamlesh; Jain, A.K.

2005-01-01

In joining of components where welding process is not possible brazing processes are employed. Value added components, high quality RF systems, UHV components of high energy accelerators, carbide tools etc. are produced using different types of brazing methods. Furnace brazing under vacuum atmosphere is the most popular and well accepted method for production of the above mentioned components and systems. For carrying out vacuum brazing successfully it is essential to have a vacuum brazing furnace with latest features of modern vacuum brazing technology. A vacuum brazing furnace has been developed and installed for carrying out brazing of components of copper, stainless steel and components made of dissimilar metals/materials. The above furnace has been designed to accommodate jobs of 700mm diameter x 2000mm long sizes with job weight of 500kgs up to a maximum temperature of 1250 degC at a vacuum of 5 x 10 -5 Torr. Oil diffusion pumping system with a combination of rotary and mechanical booster pump have been employed for obtaining vacuum. Molybdenum heating elements, radiation shield of molybdenum and Stainless Steel Grade 304 have been used. The above furnace is computer controlled with manual over ride facility. PLC and Pentium PC are integrated together to maneuver steps of operation and safety interlocks of the system. Closed loop water supply provides cooling to the system. The installation of the above system is in final stage of completion and it will be ready for use in next few months time. This paper presents insights of design and fabrication of a modern vacuum brazing furnace and its sub-system. (author)

Design of extended length submerged traveling screen and submerged bar screen fish guidance equipment

International Nuclear Information System (INIS)

Bardy, D.; Lindstrom, M.; Fechner, D.

1991-01-01

The hydropower projects on the Snake and lower Columbia Rivers in the Pacific Northwest are unique because these rivers are also the spawning grounds for migratory salmon. The salmon swim upstream from the ocean, lay their eggs, and die. The newly hatched fingerlings must then make their way past the hydroelectric dams to the ocean. Two separate bypass systems are needed, one to pass the adult fish going upstream, and one to pass the fingerlings going downstream. This paper addresses the design considerations for two of the components of the downstream migrant fish passage facilities, the extended Submerged Traveling Screen and Submerged Bar Screen

[Algal control ability of allelopathically active submerged macrophytes: a review].

Science.gov (United States)

Xiao, Xi; Lou, Li-ping; Li, Hua; Chen, Ying-xu

2009-03-01

The inhibitory effect of allelochemicals released by submerged macrophytes on phytoplankton is considered as one of the mechanisms that contribute to the stabilization of clear-water status in shallow lakes. This paper reviewed the research progress in the allelopathy of submerged macrophytes on algae from the aspects of the occurrence frequency and coverage of allelopathically active submerged macrophytes in lakes, and the kinds and allelopathical effects of the allelochemicals released from the macrophytes. The previous researches indicated that allelopathically active submerged macrophyte species such as Myriophyllum, Ceratophyllum, and Elodea were efficient to control phytoplankton, especially when their biomass was high enough, and the dominant algae were sensitive species. The allelochemicals such as hydroxybenzene released by the submerged macrophytes could inhibit the growth of algae. Different phytoplankton species exhibited different sensitivity against allelochemicals, e.g., cyanobacteria and diatom were more sensitive than green algae, while epiphytic species were less sensitive than phytoplankton. Environmental factors such as light, temperature, and nutrients could significantly affect the allelopathical effect of submerged macrophytes. The research of the allelopathy of submerged macrophytes is still at its beginning, and further researches are needed on the effects of environmental factors on the allelopathy, extraction and identification of allelochemicals, selective algal control mechanisms, and metabolism of the allelochmicals.

Association of Candidate Genes With Submergence Response in Perennial Ryegrass

Directory of Open Access Journals (Sweden)

Xicheng Wang

2017-05-01

Full Text Available Perennial ryegrass is a popular cool-season grass species due to its high quality for forage and turf. The objective of this study was to identify associations of candidate genes with growth and physiological traits to submergence stress and recovery after de-submergence in a global collection of 94 perennial ryegrass accessions. Accessions varied largely in leaf color, plant height (HT, leaf fresh weight (LFW, leaf dry weight (LDW, and chlorophyll fluorescence (Fv/Fm at 7 days of submergence and in HT, LFW and LDW at 7 days of recovery in two experiments. Among 26 candidate genes tested by various models, single nucleotide polymorphisms (SNPs in 10 genes showed significant associations with traits including 16 associations for control, 10 for submergence, and 8 for recovery. Under submergence, Lp1-SST encoding sucrose:sucrose 1-fructosyltransferase and LpGA20ox encoding gibberellin 20-oxidase were associated with LFW and LDW, and LpACO1 encoding 1-aminocyclopropane-1-carboxylic acid oxidase was associated with LFW. Associations between Lp1-SST and HT, Lp6G-FFT encoding fructan:fructan 6G-fructosyltransferase and Fv/Fm, LpCAT encoding catalase and HT were also detected under submergence stress. Upon de-submergence, Lp1-SST, Lp6G-FFT, and LpPIP1 encoding plasma membrane intrinsic protein type 1 were associated with LFW or LDW, while LpCBF1b encoding C-repeat binding factor were associated with HT. Nine significant SNPs in Lp1-SST, Lp6G-FFT, LpCAT, and LpACO1 resulted in amino acid changes with five substitutions found in Lp1-SST under submergence or recovery. The results indicated that allelic diversity in genes involved in carbohydrate and antioxidant metabolism, ethylene and gibberellin biosynthesis, and transcript factor could contribute to growth variations in perennial ryegrass under submergence stress and recovery after de-submergence.

Emission spectroscopy for coal-fired cyclone furnace diagnostics

Energy Technology Data Exchange (ETDEWEB)

Wehrmeyer, J.A.; Boll, D.E.; Smith, R. [Vanderbilt University, Nashville, TN (United States). Dept. of Mechanical Engineering

2003-08-01

Using a spectrograph and charge-coupled device (CCD) camera, ultraviolet and visible light emission spectra were obtained from a coal-burning electric utility's cyclone furnaces operating at either fuel-rich or fuel-lean conditions. The aim of this effort is to identify light emission signals that can be related to a cyclone furnace's operating condition in order to adjust its air/fuel ratio to minimize pollutant production. Emission spectra at the burner and outlet ends of cyclone furnaces were obtained. Spectra from all cyclone burners show emission lines for the trace elements Li, Na, K, and Rb, as well as the molecular species OH and CaOH. The Ca emission line is detected at the burner end of both the fuel-rich and fuellean cyclone furnaces but is not detected at the outlet ends of either furnace type. Along with the disappearance of Ca is a concomitant increase in the CaOH signal at the outlet end of both types of furnaces. The OH signal strength is in general stronger when viewing at the burner end rather than the exhaust end of both the fuel-rich and fuel-lean cyclone furnaces, probably due to high, non-equilibrium amounts of OH present inside the furnace. Only one molecular species was detected that could be used as a measure of air/fuel ratio: MgOH. It was detected at the burner end of fuel-rich cyclone furnaces but not detected in fuel-lean cyclone furnaces. More direct markers of air/fuel ratio, such as CO and 02 emission, were not detected, probably due to the generally weak nature of molecular emission relative to ambient blackbody emission present in the cyclone furnaces, even at ultraviolet wavelengths.

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.

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

A cylindrical furnace for absorption spectral studies

Indian Academy of Sciences (India)

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 ...

Modeling and Simulation of Claus Unit Reaction Furnace

Directory of Open Access Journals (Sweden)

Maryam Pahlavan

2016-01-01

Full Text Available Reaction furnace is the most important part of the Claus sulfur recovery unit and its performance has a significant impact on the process efficiency. Too many reactions happen in the furnace and their kinetics and mechanisms are not completely understood; therefore, modeling reaction furnace is difficult and several works have been carried out on in this regard so far. Equilibrium models are commonly used to simulate the furnace, but the related literature states that the outlet of furnace is not in equilibrium and the furnace reactions are controlled by kinetic laws; therefore, in this study, the reaction furnace is simulated by a kinetic model. The predicted outlet temperature and concentrations by this model are compared with experimental data published in the literature and the data obtained by PROMAX V2.0 simulator. The results show that the accuracy of the proposed kinetic model and PROMAX simulator is almost similar, but the kinetic model used in this paper has two importance abilities. Firstly, it is a distributed model and can be used to obtain the temperature and concentration profiles along the furnace. Secondly, it is a dynamic model and can be used for analyzing the transient behavior and designing the control system.

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.

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

International Nuclear Information System (INIS)

Liapis, Ioannis; Papayianni, Ioanna

2015-01-01

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 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

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.

Design of a rotating-hearth furnace

Energy Technology Data Exchange (ETDEWEB)

Behrens, H A [Verein Deutscher Eisenhuettenleute (VDEh), Duesseldorf (Germany, F.R.)

1979-10-01

Presented in two parts, this paper is intended to provide an outline of the theoretical fundamentals for the design of rotating-hearth furnaces for heating round stock and deals with the characteristic design features of such furnaces.

A comparative study of multiple regression analysis and back ...

Indian Academy of Sciences (India)

Abhijit Sarkar

artificial neural network (ANN) models to predict weld bead geometry and HAZ width in submerged arc welding ... Keywords. Submerged arc welding (SAW); multi-regression analysis (MRA); artificial neural network ..... Degree of freedom.

Glass: Rotary Electric Glass Furnace

Energy Technology Data Exchange (ETDEWEB)

Recca, L.

1999-01-29

Compared to conventional gas-fired furnaces, the new rotary electric furnace will increase energy efficiency while significantly reducing air emissions, product turnaround time, and labor costs. As this informative new fact sheet explains, the thousand different types of glass optical blanks produced for the photonics industry are used for lasers, telescopes, cameras, lights, and many other products.

Industrial furnace with improved heat transfer

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, M.; Lingle, T.M.

1993-07-20

A method is described for effecting improved heat transfer with in an industrial furnace having a cylindrical furnace section, a door at one end of the furnace section, an end plate at the opposite end of the section a circular fan plate concentrically positioned within the furnace section to define a cylindrical fan chamber between the plate and the end section with a fan there between and a heat treat chamber between the plate and the door, the fan plate defining a non-orificing annular space extending between the interior of the cylindrical furnace section and the outer edge of the plate, the plate having a centrally located under-pressure opening extending there through and a plurality of circumferentially spaced tubular heating elements extending through the annular space into the heat treating chamber, the method comprising the steps of: (a) heating the heating elements to a temperature which is hotter that the temperature of the work within the heat treating chamber; (b) rotating the fan at a speed sufficient to form a portion of the furnace atmosphere as a wind mass swirling about the fan chamber; (c) propagating the wind mass through the annular space into the heat treating chamber as a swirling wind mass in the form of an annulus, the wind mass impinging the heating elements to establish heat transfer contact therewith while the mass retains its annulus shape until contacting the door and without any significant movement of the wind mass into the center of the heat treating chamber; (d) drawing the wind mass through the under-pressure zone after the wind mass comes into heat transfer contact with the work in the heat treating chamber; and (e) thereafter heating the work by radiation from the beating elements at high furnace temperatures in excess of about 1,600 F.

Optical cavity furnace for semiconductor wafer processing

Science.gov (United States)

Sopori, Bhushan L.

2014-08-05

An optical cavity furnace 10 having multiple optical energy sources 12 associated with an optical cavity 18 of the furnace. The multiple optical energy sources 12 may be lamps or other devices suitable for producing an appropriate level of optical energy. The optical cavity furnace 10 may also include one or more reflectors 14 and one or more walls 16 associated with the optical energy sources 12 such that the reflectors 14 and walls 16 define the optical cavity 18. The walls 16 may have any desired configuration or shape to enhance operation of the furnace as an optical cavity 18. The optical energy sources 12 may be positioned at any location with respect to the reflectors 14 and walls defining the optical cavity. The optical cavity furnace 10 may further include a semiconductor wafer transport system 22 for transporting one or more semiconductor wafers 20 through the optical cavity.

Effects of body formulation and firing temperature to properties of ceramic tile incorporated with electric arc furnace (EAF) slag waste

Science.gov (United States)

Sharif, Nurulakmal Mohd; Lim, Chi Yang; Teo, Pao Ter; Seman, Anasyida Abu

2017-07-01

Significant quantities of sludge and slag are generated as waste materials or by-products from steel industries. One of the by-products is Electric Arc Furnace (EAF) steel slag which consists of oxides such as CaO, Al2O3 and FeO. This makes it possible for slag to partially replace the raw materials in ceramic tile production. In our preliminary assessment of incorporating the EAF slag into ceramic tile, it was revealed that at fixed firing temperature of 1150°C, the tile of composition 40 wt.% EAF slag - 60 wt.% ball clay has comparable properties with commercial ceramic tile. Thus, this current study would focus on effects of body formulation (different weight percentages of K-feldspar and silica) and different firing temperatures to properties of EAF slag added ceramic tile. EAF slag from Southern Steel Berhad (SSB) was crushed into micron size (EAF slag content was 40 wt.%) and milled with ball clay, K-feldspar and silica before compacted and fired at 1125°C and 1150°C. The EAF slag added tile was characterized in terms of water absorption, apparent porosity, bulk density, modulus of rupture (MOR) and phase analysis via X-ray diffraction (XRD). The composition of 40 wt.% EAF slag - 30 wt.% ball clay - 10 wt.% K-feldspar - 20 wt.% silica (10F_20S), fired at 1150°C showed the lowest water absorption, apparent porosity and highest bulk density due to enhancement of densification process during firing. However, the same composition of ceramic tile (10F_20S) had the highest MOR at lower firing temperature of 1125°C, contributed by presence of the highest total amount of anorthite and wollastonite reinforcement crystalline phases (78.40 wt.%) in the tile. Overall, both the water absorption and MOR of all ceramic tiles surpassed the requirement regulated by MS ISO 13006:2014 Standard (Annex G: Dry-pressed ceramic tile with low water absorption, Eb ≤ 0.50 % and minimum MOR of 35 MPa).

Submerged cutting characteristics of abrasive suspension jet

International Nuclear Information System (INIS)

Shimizu, Seiji; Peng, Guoyi; Oguma, Yasuyuki; Nishikata, Hiroki

2015-01-01

An abrasive suspension jet (ASJ) formed by propelling abrasive suspension through a nozzle has a greater cutting capability than the conventional abrasive water jet. However the cutting capability of submerged ASJs decreases drastically with increasing the standoff distance and the pressure around the jet. A sheathed nozzle nozzle with ventilation for ASJs has been developed as a mean of extending the effective stand-off distance and improving the cutting capabilities under submerged condition. In the present investigation, cutting tests by ASJs in air and under submerged condition are conducted with specimens of aluminum alloy. Air coated ASJs are formed by using a sheathed nozzle with ventilation. The relative cutting depth is defined as the cutting depth is arranged effectually by the cavitation number based on the cavity pressure measured at the sheath. (author)

Narrow gap mechanised arc welding in nuclear components manufactured by AREVA NP

International Nuclear Information System (INIS)

Peigney, A.

2007-01-01

Nuclear components require welds of irreproachable and reproducible quality. Moreover, for a given welding process, productivity requirements lead to reduce the volume of deposited metal and thus to use narrow gap design. In the shop, narrow gap Submerged Arc Welding process (SAW) is currently used on rotating parts in flat position for thicknesses up to 300 mm. Welding is performed with one or two wires in two passes per layer. In Gas Tungsten Arc Welding process (GTAW), multiple applications can be found because this process presents the advantage of allowing welding in all positions. Welding is performed in one or two passes per layer. The process is used in factory and on the nuclear sites for assembling new components but also for replacing components and for repairs. Presently, an increase of productivity of the process is sought through the use of hot wire and/or two wires. Concerning Gas Metal Arc Welding process (GMAW), its use is growing for nuclear components, including narrow gap applications. This process, limited in its applications in the past on account of the defects it generated, draws benefit from the progress of the welding generators. Then it is possible to use this efficient process for high security components such as those of nuclear systems. It is to be noted that the process is applicable in the various welding positions as it is the case for GTAW, while being more efficient than the latter. This paper presents the state of the art in the use of narrow gap mechanised arc welding processes by AREVA NP units. (author) [fr

Submerged cultivation of medicinal mushrooms: bioprocesses and products (review).

Science.gov (United States)

Elisashvili, Vladimir

2012-01-01

Medicinal mushrooms belonging to higher Basidiomycetes are an immensely rich yet largely untapped resource of useful, easily accessible, natural compounds with various biological activities that may promote human well-being. The medicinal properties are found in various cellular components and secondary metabolites (polysaccharides, proteins and their complexes, phenolic compounds, polyketides, triterpenoids, steroids, alkaloids, nucleotides, etc.), which have been isolated and identified from the fruiting bodies, culture mycelium, and culture broth of mushrooms. Some of these compounds have cholesterol-lowering, anti-diabetic, antioxidant, antitumor, immunomodulating, antimicrobial, and antiviral activities ready for industrial trials and further commercialization, while others are in various stages of development. Recently, the submerged cultivation of medicinal mushrooms has received a great deal of attention as a promising and reproducible alternative for the efficient production of mushroom mycelium and metabolites. Submerged cultivation of mushrooms has significant industrial potential, but its success on a commercial scale depends on increasing product yields and development of novel production systems that address the problems associated with this technique of mushroom cultivation. In spite of many researchers' efforts for the production of bioactive metabolites by mushrooms, the physiological and engineering aspects of submerged cultures are still far from being thoroughly studied. The vast majority of studies have focused on polysaccharide and ganoderic acid production in submerged cultivation of medicinal mushrooms, and very little has been written so far on the antioxidant and hemagglutinating activity of submerged mushroom cultures. The purpose of this review is to provide an update of the present state of the art and future prospects of submerged cultivation of medicinal mushrooms to produce mycelium and bioactive metabolites, and to make a

Alternative fuels for multiple-hearth furnaces

Energy Technology Data Exchange (ETDEWEB)

Bracket, B D; Lawson, T U

1980-04-01

Results are described of a feasibility study on the use of refuse-derived fuel, shredded paper, wood waste, coal, and waste oil in multiple-hearth furnaces at the Lower Molonglo Water Quality Control Centre in Australia. An assessment of waste fuel availability and characteristics is given, and a summary is made of the technical and economic aspects of using these alternative fuels and of minimizing furnace fuel requirements by reducing sludge moisture. The recommended method of reducing fuel oil consumption in the furnace is shown to be sludge drying, using process exhaust heat in a rotary dryer.

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.)

[Effects of light on submerged macrophytes in eutrophic water: research progress].

Science.gov (United States)

Li-Sha, Zou; Ze-Yu, Nie; Xiao-Yan, Yao; Ji-Yan, Shi

2013-07-01

The restoration of submerged macrophytes is the key to remediate eutrophic water and maintain the health of aquatic ecosystem, while light is the main limiting factor. This paper summarized the factors affecting the light extinction in water and the mechanisms of light intensity affecting the physiology of submerged macrophytes, with the focuses on the metabolic mechanisms of carbon, nitrogen, and phosphorus, the responses of antioxidant enzyme system, and the feedbacks of pigment composition and concentration in the common submerged macrophytes under low light stress. Several engineering techniques applied in the ecological restoration of submerged macrophytes were presented, and the framework of the restoration of submerged macrophytes in eutrophic water was proposed. Some problems in current research and several suggestions on future research were addressed, which could help the related research and engineering practices.

Dynamics and control of a gas-fired furnace

NARCIS (Netherlands)

Roffel, B.; Rijnsdorp, J.E.

1974-01-01

A non-linear model has been developed for a gas-fired furnace in which oil is heated. The model is applicable from minimum to maximum heat load of the furnace. The dynamics of the model have been compared to experimental results, which were obtained for a pilot-scale furnace. They are in good

Transcriptomic Analysis of Gibberellin- and Paclobutrazol-Treated Rice Seedlings under Submergence

Directory of Open Access Journals (Sweden)

Jing Xiang

2017-10-01

Full Text Available Submergence stress is a limiting factor for rice growing in rainfed lowland areas of the world. It is known that the phytohormone gibberellin (GA has negative effects on submergence tolerance in rice, while its inhibitor paclobutrazol (PB does the opposite. However, the physiological and molecular basis underlying the GA- and PB-regulated submergence response remains largely unknown. In this study, we reveal that PB could significantly enhance rice seedling survival by retaining a higher level of chlorophyll content and alcohol dehydrogenase activity, and decelerating the consumption of non-structure carbohydrate when compared with the control and GA-treated samples. Further transcriptomic analysis identified 3936 differentially expressed genes (DEGs among the GA- and PB-treated samples and control, which are extensively involved in the submergence and other abiotic stress responses, phytohormone biosynthesis and signaling, photosynthesis, and nutrient metabolism. The results suggested that PB enhances rice survival under submergence through maintaining the photosynthesis capacity and reducing nutrient metabolism. Taken together, the current study provided new insight into the mechanism of phytohormone-regulated submergence response in rice.

Holden gas-fired furnace baseline data. Revision 1

International Nuclear Information System (INIS)

Weatherspoon, K.A.

1996-11-01

The Holden gas-fired furnace is used in the enriched uranium recovery process to dry and combust small batches of combustibles. The ash is further processed. The furnace operates by allowing a short natural gas flame to burn over the face of a wall of porous fire brick on two sides of the furnace. Each firing wall uses two main burners and a pilot burner to heat the porous fire brick to a luminous glow. Regulators and orifice valves are used to provide a minimum gas pressure of 4 in. water column at a rate of approximately 1,450 scf/h to the burners. The gas flow rate was calculated by determining the gas flow appropriate for the instrumentation in the gas line. Observed flame length and vendor literature were used to calculate pilot burner gas consumption. Air for combustion, purging, and cooling is supplied by a single blower. Rough calculations of the air-flow distribution in piping entering the furnace show that air flow to the burners approximately agrees with the calculated natural gas flow. A simple on/off control loop is used to maintain a temperature of 1,000 F in the furnace chamber. Hoods and glove boxes provide contamination control during furnace loading and unloading and ash handling. Fan EF-120 exhausts the hoods, glove boxes, and furnace through filters to Stack 33. A review of the furnace safety shows that safety is ensured by design, interlocks, procedure, and a safety system. Recommendations for safety improvements include installation of both a timed ignition system and a combustible-gas monitor near the furnace. Contamination control in the area could be improved by redesigning the loading hood face and replacing worn gaskets throughout the system. 33 refs., 16 figs

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.

Furnace for treating bituminous material

Energy Technology Data Exchange (ETDEWEB)

Klotzer, M

1922-04-28

A furnace with saw-teeth-like profiled hearth, which by means of a kind of shaking slide executes a backward and forward motion, for carrying out the process according to Patent 422,391. It is characterized in that the stroke of the hearth moving in the furnace is smaller than the length of the profile tooth and the height of the feed is held less than the tooth height.

Nitrogen oxide emissions from a kraft recovery furnace

International Nuclear Information System (INIS)

Prouty, A.L.; Stuart, R.C.; Caron, A.L.

1993-01-01

Nitrogen Oxide (NOx) emissions from a rebuilt kraft recovery furnace slightly exceeded the specified limit of 1.1 lb/ton (0.55 kg/metric ton) of black-liquor solids. Mill trials were undertaken to determine whether NOx emissions could be minimized by modifying furnace operation. NOx emissions increased when secondary air was shifted to tertiary ports. NOx emissions fell when the amounts of primary and total air were decreased, but this increased emissions of other pollutants. After demonstrating that best operation of the furnace could not meet the permit with an emissions limit that matched the furnace's performance at best operation

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.

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).

Application of Carbon Composite Bricks for Blast Furnace Hearth

Science.gov (United States)

Zuo, Haibin; Wang, Cong; Zhang, Jianliang; Zhao, Yongan; Jiao, Kexin

Traditional refractory materials for blast furnace hearth lining are mainly composed of carbon bricks and the ceramic cup. However, these materials can't meet the demands for long service life design of blast furnaces. In this paper, a new refractory called carbon composite brick (CCB) was introduced, which combined the advantages of carbon bricks and the ceramic cup. In this case, the resistance of the CCB against corrosion was equal to the ceramic cup and the thermal conductivity of the CCB was equal to carbon bricks. From the results of more than 20 blast furnaces, the CCB could be well used in small blast furnaces and large blast furnaces. In the bad condition of low grade burden and high smelting intensity, the CCB gave full play to the role of cooling system, and effectively resisted the erosion of hot metal to improve the service life of blast furnaces.

Predictive control of thermal state of blast furnace

Science.gov (United States)

Barbasova, T. A.; Filimonova, A. A.

2018-05-01

The work describes the structure of the model for predictive control of the thermal state of a blast furnace. The proposed model contains the following input parameters: coke rate; theoretical combustion temperature, comprising: natural gas consumption, blasting temperature, humidity, oxygen, blast furnace cooling water; blast furnace gas utilization rate. The output parameter is the cast iron temperature. The results for determining the cast iron temperature were obtained following the identification using the Hammerstein-Wiener model. The result of solving the cast iron temperature stabilization problem was provided for the calculated values of process parameters of the target area of the respective blast furnace operation mode.

The fate of injectant coal in blast furnaces: The origin of extractable materials of high molecular mass in blast furnace carryover dusts

Energy Technology Data Exchange (ETDEWEB)

Dong, S.N.; Wu, L.; Paterson, N.; Herod, A.A.; Dugwell, D.R.; Kandiyoti, R. [University of London Imperial College of Science & Technology, London (United Kingdom). Dept. of Chemical Engineering

2005-07-01

The aim of the work was to investigate the fate of injectant coal in blast furnaces and the origin of extractable materials in blast furnace carryover dusts. Two sets of samples including injectant coal and the corresponding carryover dusts from a full sized blast furnace and a pilot scale rig have been examined. The samples were extracted using 1-methyl-2-pyrrolidinone (NMP) solvent and the extracts studied by size exclusion chromatography (SEC). The blast furnace carryover dust extracts contained high molecular weight carbonaceous material, of apparent mass corresponding to 10{sup 7}-10{sup 8} u, by polystyrene calibration. In contrast, the feed coke and char prepared in a wire mesh reactor under high temperature conditions did not give any extractable material. Meanwhile, controlled combustion experiments in a high-pressure wire mesh reactor suggest that the extent of combustion of injectant coal in the blast furnace tuyeres and raceways is limited by time of exposure and very low oxygen concentration. It is thus likely that the extractable, soot-like material in the blast furnace dust originated in tars is released by the injectant coal. Our results suggest that the unburned tars were thermally altered during the upward path within the furnace, giving rise to the formation of heavy molecular weight (soot-like) materials.

Contrasting Changes Caused by Drought and Submergence Stresses in Bermudagrass (Cynodon dactylon)

Science.gov (United States)

Ye, Tiantian; Shi, Haitao; Wang, Yanping; Chan, Zhulong

2015-01-01

In this study, we investigated the mechanisms by which bermudagrass withstands the drought and submergence stresses through physiological, proteomic and metabolomic approaches. The results showed that significant physiological changes were observed after drought treatment, while only slight changes after submergence treatment, including compatible solute contents, ROS levels and antioxidant enzyme activities. Proteomics results showed that 81 proteins regulated by drought or submergence treatment were identified by MALDI-TOF-MS. Among them, 76 proteins were modulated by drought stress with 46 increased abundance and 30 decreased abundance. Forty-five showed abundance changes after submergence treatment with 10 increased and 35 decreased. Pathway enrichment analysis revealed that pathways of amino acid metabolism and mitochondrial electron transport/ATP synthesis were only enriched by drought treatment, while other pathways including photosynthesis, biodegradation of xenobiotics, oxidative pentose phosphate, glycolysis and redox were commonly over-represented after both drought and submergence treatments. Metabolomic analysis indicated that most of the metabolites were up-regulated by drought stress, while 34 of 40 metabolites contents exhibited down-regulation or no significant changes when exposed to submergence stress, including sugars and sugar alcohols. These data indicated that drought stress extensively promoted photosynthesis and redox metabolisms while submergence stress caused declined metabolisms and dormancy in Cynodon dactylon. Taken together, the quiescence strategy with retarded growth might allow bermudagrass to be adaptive to long-term submerged environment, while activation of photosynthesis and redox, and accumulation of compatible solutes and molecular chaperones increased bermudagrass tolerance to drought stress. PMID:26617615

Submergible barge retrievable storage and permanent disposal system for radioactive waste

Science.gov (United States)

Goldsberry, Fred L.; Cawley, William E.

1981-01-01

A submergible barge and process for submerging and storing radioactive waste material along a seabed. A submergible barge receives individual packages of radwaste within segregated cells. The cells are formed integrally within the barge, preferably surrounded by reinforced concrete. The cells are individually sealed by a concrete decking and by concrete hatch covers. Seawater may be vented into the cells for cooling, through an integral vent arrangement. The vent ducts may be attached to pumps when the barge is bouyant. The ducts are also arranged to promote passive ventilation of the cells when the barge is submerged. Packages of the radwaste are loaded into individual cells within the barge. The cells are then sealed and the barge is towed to the designated disposal-storage site. There, the individual cells are flooded and the barge will begin descent controlled by a powered submarine control device to the seabed storage site. The submerged barge will rest on the seabed permanently or until recovered by a submarine control device.

The Performance and Fouling Control of Submerged Hollow Fiber (HF Systems: A Review

Directory of Open Access Journals (Sweden)

Ebrahim Akhondi

2017-07-01

Full Text Available The submerged membrane filtration concept is well-established for low-pressure microfiltration (MF and ultrafiltration (UF applications in the water industry, and has become a mainstream technology for surface-water treatment, pretreatment prior to reverse osmosis (RO, and membrane bioreactors (MBRs. Compared to submerged flat sheet (FS membranes, submerged hollow fiber (HF membranes are more common due to their advantages of higher packing density, the ability to induce movement by mechanisms such as bubbling, and the feasibility of backwashing. In view of the importance of submerged HF processes, this review aims to provide a comprehensive landscape of the current state-of-the-art systems, to serve as a guide for further improvements in submerged HF membranes and their applications. The topics covered include recent developments in submerged hollow fiber membrane systems, the challenges and developments in fouling-control methods, and treatment protocols for membrane permeability recovery. The highlighted research opportunities include optimizing the various means to manipulate the hydrodynamics for fouling mitigation, developing online monitoring devices, and extending the submerged HF concept beyond filtration.

Macroinvertebrates associated with two submerged macrophytes ...

African Journals Online (AJOL)

Macroinvertebrates associated with two submerged macrophytes, Lagarosiphon ilicifolius and Vallisneria aethiopica , in the Sanyati Basin, Lake Kariba, Zimbabwe: effect of plant morphological complexity.

Metal halide arc discharge lamp having short arc length

Science.gov (United States)

Muzeroll, Martin E. (Inventor)

1994-01-01

A metal halide arc discharge lamp includes a sealed light-transmissive outer jacket, a light-transmissive shroud located within the outer jacket and an arc tube assembly located within the shroud. The arc tube assembly includes an arc tube, electrodes mounted within the arc tube and a fill material for supporting an arc discharge. The electrodes have a spacing such that an electric field in a range of about 60 to 95 volts per centimeter is established between the electrodes. The diameter of the arc tube and the spacing of the electrodes are selected to provide an arc having an arc diameter to arc length ratio in a range of about 1.6 to 1.8. The fill material includes mercury, sodium iodide, scandium tri-iodide and a rare gas, and may include lithium iodide. The lamp exhibits a high color rendering index, high lumen output and high color temperature.

BPM Motors in Residential Gas Furnaces: What are the Savings?

OpenAIRE

Lutz, James; Franco, Victor; Lekov, Alex; Wong-Parodi, Gabrielle

2006-01-01

Residential gas furnaces contain blowers to distribute warm air. Currently, furnace blowers use either a Permanent Split Capacitor (PSC) or a Brushless Permanent Magnet (BPM) motor. Blowers account for the majority of furnace electricity consumption. Therefore, accurate determination of the blower electricity consumption is important for understanding electricity consumption of furnaces. The electricity consumption of blower motors depends on the static pressure across the blower. This p...

Monitoring ARC services with GangliARC

International Nuclear Information System (INIS)

Cameron, D; Karpenko, D

2012-01-01

Monitoring of Grid services is essential to provide a smooth experience for users and provide fast and easy to understand diagnostics for administrators running the services. GangliARC makes use of the widely-used Ganglia monitoring tool to present web-based graphical metrics of the ARC computing element. These include statistics of running and finished jobs, data transfer metrics, as well as showing the availability of the computing element and hardware information such as free disk space left in the ARC cache. Ganglia presents metrics as graphs of the value of the metric over time and shows an easily-digestable summary of how the system is performing, and enables quick and easy diagnosis of common problems. This paper describes how GangliARC works and shows numerous examples of how the generated data can quickly be used by an administrator to investigate problems. It also presents possibilities of combining GangliARC with other commonly-used monitoring tools such as Nagios to easily integrate ARC monitoring into the regular monitoring infrastructure of any site or computing centre.

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.

Programmable temperature regulator of VAO-1 furnace

International Nuclear Information System (INIS)

Zahalka, F.

1979-01-01

A programmable temperature controller is described for a furnace for high-level waste processing. Furnace temperature is controlled by a program compiled from a combination of 3 parts with different linear increments or decrements of time dependent temperature and 2 parts with isothermal control for over a preset period. The equipment consists essentially of a programming unit, a programmed digital-to-analog converter and a power unit. The design is described in detail and its specifications are given. The maximum operating temperature of 1500 degC may be reached in the furnace charge section. (B.S.)

A new compact fixed-point blackbody furnace

International Nuclear Information System (INIS)

Hiraka, K.; Oikawa, H.; Shimizu, T.; Kadoya, S.; Kobayashi, T.; Yamada, Y.; Ishii, J.

2013-01-01

More and more NMIs are realizing their primary scale themselves with fixed-point blackbodies as their reference standard. However, commercially available fixed-point blackbody furnaces of sufficient quality are not always easy to obtain. CHINO Corp. and NMIJ, AIST jointly developed a new compact fixed-point blackbody furnace. The new furnace has such features as 1) improved temperature uniformity when compared to previous products, enabling better plateau quality, 2) adoption of the hybrid fixed-point cell structure with internal insulation to improve robustness and thereby to extend lifetime, 3) easily ejectable and replaceable heater unit and fixed-point cell design, leading to reduced maintenance cost, 4) interchangeability among multiple fixed points from In to Cu points. The replaceable cell feature facilitates long term maintenance of the scale through management of a group of fixed-point cells of the same type. The compact furnace is easily transportable and therefore can also function as a traveling standard for disseminating the radiation temperature scale, and for maintaining the scale at the secondary level and industrial calibration laboratories. It is expected that the furnace will play a key role of the traveling standard in the anticipated APMP supplementary comparison of the radiation thermometry scale

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.

Electric melting furnace for waste solidification

International Nuclear Information System (INIS)

Masaki, Toshio.

1990-01-01

To avoid electric troubles or reduction of waste processing performance even when platinum group elements are contained in wastes to be applied with glass solidification. For this purpose, a side electrode is disposed to the side wall of a melting vessel and a central electrode serving as a counter electrode is disposed about at the center inside the melting vessel. With such a constitution, if conductive materials are deposited at the bottom of the furnace or the bottom of the melting vessel, heating currents flow selectively between the side electrode and the central electrode. Accordingly, no electric currents flow through the conductive deposits thereby enabling to prevent abnormal heating in the bottom of the furnace. Further, heat generated by electric supply between the side electrode and the central electrode is supplied efficiently to raw material on the surface of the molten glass liquid to improve the processing performance. Further, disposition of the bottom electrode at the bottom of the furnace enables current supply between the central electrode and the bottom electrode to facilitate the temperature control for the molten glass in the furnace than in the conventional structure. (I.S.)

Canopy Modeling of Aquatic Vegetation: Construction of Submerged Vegetation Index

Science.gov (United States)

Ma, Z.; Zhou, G.

2018-04-01

The unique spectral characteristics of submerged vegetation in wetlands determine that the conventional terrestrial vegetation index cannot be directly employed to species identification and parameter inversion of submerged vegetation. Based on the Aquatic Vegetation Radiative Transfer model (AVRT), this paper attempts to construct an index suitable for submerged vegetation, the model simulated data and a scene of Sentinel-2A image in Taihu Lake, China are utilized for assessing the performance of the newly constructed indices and the existent vegetation indices. The results show that the angle index composed by 525 nm, 555 nm and 670 nm can resist the effects of water columns and is more sensitive to vegetation parameters such as LAI. Furthermore, it makes a well discrimination between submerged vegetation and water bodies in the satellite data. We hope that the new index will provide a theoretical basis for future research.

Leaf gas films contribute to rice (Oryza sativa) submergence tolerance during saline floods

DEFF Research Database (Denmark)

Herzog, Max; Konnerup, Dennis; Pedersen, Ole

2018-01-01

Floods and salinization of agricultural land adversely impact global rice production. We investigated whether gas films on leaves of submerged rice delay salt entry during saline submergence. Two-week-old plants with leaf gas films (+GF) or with gas films experimentally removed (-GF) were submerged...

Development of New Submergence Tolerant Rice Variety for Bangladesh Using Marker-Assisted Backcrossing

Directory of Open Access Journals (Sweden)

Khandakar Md Iftekharuddaula

2015-01-01

Full Text Available Submergence tolerant high yielding rice variety was developed using BR11 as a recipient parent applying foreground, phenotypic and background selection approaches. Recombinant selection was found essential to minimize linkage drag by BC2F2 generation. Without recombinant selection, the introgression size in the backcross recombinant lines (BRLs was approximately 15 Mb on the carrier chromosome. The BRLs were found submergence tolerance compared to the check varieties under complete submergence for two weeks at Bangladesh Rice Research Institute, and produced higher yield compared to the isogenic Sub1-line under controlled submerged condition. The BRL IR85260-66-654-Gaz2 was released as BRRI dhan52 in 2010, which was the first high yielding submergence tolerant variety in Bangladesh. BRRI dhan52 produced grain yield ranging from 4.2 to 5.2 t/hm2 under different flash flood prone areas of Bangladesh in three consecutive seasons. The study demonstrated the efficiency of recombinant selection and better adaptability of the newly released submergence tolerant high yielding variety in flash flood prone different areas of the country with respect to submergence tolerance and yield potential.

Vibrational analysis of submerged cylindrical shells based on elastic foundations

International Nuclear Information System (INIS)

Shah, A.G.; Naeem, M.N.

2014-01-01

In this study a vibration analysis was performed of an isotropic cylindrical shell submerged in fluid, resting on Winkler and Pasternak elastic foundations for simply supported boundary condition. Love's thin shell theory was exploited for strain- and curvature- displacement relationship. Shell problem was solved by using wave propagation approach. Influence of fluid and Winkler as well as Pasternak elastic foundations were studied on the natural frequencies of submerged isotropic cylindrical shells. Results were validated by comparing with the existing results in literature. Vibration, Submerged cylindrical shell, Love's thin shell theory, Wave propagation method, Winkler and Pasternak foundations. (author)

Arc Shape Characteristics with Ultra-High-Frequency Pulsed Arc Welding

Directory of Open Access Journals (Sweden)

Mingxuan Yang

2017-01-01

Full Text Available Arc plasma possesses a constriction phenomenon with a pulsed current. The constriction is created by the Lorentz force, the radial electromagnetic force during arc welding, which determines the energy distribution of the arc plasma. Welding experiments were carried out with ultra-high-frequency pulsed arc welding (UHFP-AW. Ultra-high-speed camera observations were produced for arc surveillance. Hue-saturation-intensity (HSI image analysis was used to distinguish the regions of the arc plasma that represented the heat energy distribution. The measurement of arc regions indicated that, with an ultra-high-frequency pulsed arc, the constriction was not only within the decreased arc geometry, but also within the constricted arc core region. This can be checked by the ratio of the core region to the total area. The arc core region expanded significantly at 40 kHz at 60 A. A current level of 80 A caused a decrease in the total region of the arc. Meanwhile, the ratio of the core region to the total increased. It can be concluded that arc constriction depends on the increased area of the core region with the pulsed current (>20 kHz.

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

Assessment of selected furnace technologies for RWMC waste

International Nuclear Information System (INIS)

Batdorf, J.; Gillins, R.; Anderson, G.L.

1992-03-01

This report provides a description and initial evaluation of five selected thermal treatment (furnace) technologies, in support of earlier thermal technologies scoping work for application to the Idaho National Engineering Laboratory Radioactive Waste Management Complex (RWMC) buried wastes. The cyclone furnace, molten salt processor, microwave melter, ausmelt (fuel fired lance) furnace, and molten metal processor technologies are evaluated. A system description and brief development history are provided. The state of development of each technology is assessed, relative to treatment of RWMC buried waste

Internal heat exchange tubes for industrial furnaces

Energy Technology Data Exchange (ETDEWEB)

Hoetzl, M.; Lingle, T.M.

1992-05-26

This patent describes a method for cooling the work within an industrial furnace. It comprises providing a longitudinally extending outer tube which extends into the furnace having a closed axial end and an open axial end; providing a preformed inner tube open at both ends within the outer tube; injecting a coolant into the inner tube so that the coolant flows from one axial end of the tube out the opposite end adjacent the closed end of the outer tube, and from the closed end of the outer tube to the open end thereof; circulating a gas within the furnace against the outer tube to effect heat transfer therewith.

Uranium casting furnace automatic temperature control development

International Nuclear Information System (INIS)

Lind, R.F.

1992-01-01

Development of an automatic molten uranium temperature control system for use on batch-type induction casting furnaces is described. Implementation of a two-color optical pyrometer, development of an optical scanner for the pyrometer, determination of furnace thermal dynamics, and design of control systems are addressed. The optical scanning system is shown to greatly improve pyrometer measurement repeatability, particularly where heavy floating slag accumulations cause surface temperature gradients. Thermal dynamics of the furnaces were determined by applying least-squares system identification techniques to actual production data. A unity feedback control system utilizing a proportional-integral-derivative compensator is designed by using frequency-domain techniques. 14 refs

A furnace for firing carbon products

Energy Technology Data Exchange (ETDEWEB)

Sudavskii, A M

1979-12-05

A furnace for firing carbon products is patented that consists of several chambers with a perforated hearth, which are interconnected by a lower and an upper reservoir with a locking fixture, and a flue. In order to intensify the firing process by increasing the specific hearth productivity, the flue is connected to the upper reservoir. A block diagram of the patented furnace is given, together with a description of its operation.

Methods for monitoring heat flow intensity in the blast furnace wall

Directory of Open Access Journals (Sweden)

L'. Dorčák

2010-04-01

Full Text Available In this paper we present the main features of an online system for real-time monitoring of the bottom part of the blast furnace. Firstly, monitoring concerns the furnace walls and furnace bottom temperatures measurement and their visualization. Secondly, monitored are the heat flows of the furnace walls and furnace bottom. In the case of two measured temperatures, the heat flow is calculated using multi-layer implicit difference scheme and in the case of only one measured temperature, the heat flow is calculated using a method based on application of fractional-order derivatives. Thirdly, monitored is the theoretical temperature of the blast furnace combustion process in the area of tuyeres.

Microcystin production in epiphytic cyanobacteria on submerged macrophytes.

Science.gov (United States)

Mohamed, Zakaria A; Al Shehri, Abdulrahman M

2010-06-15

Cyanotoxins have been largely studied in planktonic and benthic cyanobacteria, but microcystin (MCYST) production in epiphytic cyanobacteria has not been reported yet. The present study reports for the first time the MCYST production in epiphytic cyanobacteria on submerged macrophytes. During this study, four common submerged macrophytes in eutrophic pond in Saudi Arabia were surveyed for the presence of toxic epiphytic cyanobacteria. The results showed that chlorophyll-a and total biovolume of epiphytic cyanobacteria differed significantly among submerged plants with highest values obtained in Stratiotes aloides and lowest in Elodea canadensis. Epiphytic materials collected from Ceratophyllum demersum and S. aloides had higher species diversities than materials collected from E. canadensis and Myriophyllum verticillatum. The cyanobacteria, Merismopedia tenuissima and Leptolyngbya boryana were recorded with a high abundance in epiphytic materials collected from all submerged macrohpytes. Based on Enzyme-linked immunosorbent assay (ELISA), these two species were found to produce MCYSTs (MCYSTs) with concentrations of 1438 and 630 microg g(-1) dry weight, respectively. HPLC analysis of the methanolic extracts of the two species showed that M. tenuissima extract contained MCYST-RR and -LR/demethyl LR plus 3 minor unidentified MCYSTs, while L. boryana extract contained MCYST-YR, -LR/demethyl LR, and 2 minor unidentified MCYSTs. This study suggests that epiphytic species should be considered during monitoring of toxic cyanobacteria in water sources. 2010 Elsevier Ltd. All rights reserved.

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.

Fluxless furnace brazing and its theoretical fundamentals

International Nuclear Information System (INIS)

Lison, R.

1979-01-01

In this paper the theoretical fundamental of fluxless furnace brazing are described. The necessary conditions for a wetting in the vacuum, under a inert-gas and with a reducing gas are discussed. Also other methods to reduce the oxygen partial pressure are described. Some applications of fluxless furnace brazing are outlined. (orig.) [de

Heat transfer study of a submerged reactor channel under boil-off condition

Energy Technology Data Exchange (ETDEWEB)

Mukhopadhyay, Deb [Bhabha Atomic Research Centre, Mumbai (India). Reactor Safety Div.; Sahoo, P.K. [Indian Institute of Technology, Roorkee (India). Dept. of Mechanical and Industrial Engineering; Ghosh, A.K. [Bhabha Atomic Research Centre, Mumbai (India). Health, Safety and Environment Group

2012-12-15

Experiments have been carried out to study the heatup behavior of a single segmented reactor channel for Pressurized Heavy Water Reactor under submerged, partially submerged and exposed conditions. This situation may arise from a severe accident scenario of Pressurised Heavy Water Reactors where full or segmented reactor channels are likely to be disassembled and form a submerged debris bed. An assembly of electrical heater rod, simulating fuel bundle and channel components like Pressure Tube and Calandria Tube constitutes the segmented reactor channel. Heatup of this assembly is observed with respect to different water levels ranging from full submergence to totally exposed and power levels of 6-8 kW, typical to decay power level. It has been observed from the set of experiment that fuel bundle local dry out followed by heatup does not happen till the bundle is partially submerged. Temperature excursion of the bundle is evident when the bundle is exposed to steam-air environment. (orig.)

THE STUDY ON THE DURABILITY OF SUBMERGED STRUCTURE DISPLACEMENT DUE TO CONCRETE FAILURE

Directory of Open Access Journals (Sweden)

M. Mohd

2016-09-01

Full Text Available Concrete structures that exposed to marine environments are subjected to multiple deterioration mechanisms. An overview of the existing technology for submerged concrete, pressure resistant, concrete structures which related such as cracks, debonds, and delamination are discussed. Basic knowledge related to drowning durability such as submerged concrete structures in the maritime environment are the durability of a concrete and the ability to resist to weathering, chemical attack, abrasion or other deterioration processes. The measuring techniques and instrumentation for geometrical monitoring of submerged structural displacements have traditionally been categorized into two groups according to the two main groups, namely as geodetic surveying and geotechnical structural measurements of local displacements. This paper aims to study the durability of submerged concrete displacement and harmful effects of submerged concrete structures.

Impacts of climate change on submerged and emergent wetland plants

Science.gov (United States)

Frederick T. Short; Sarian Kosten; Pamela A. Morgan; Sparkle L Malone; Gregg E. Moore

2016-01-01

Submerged and emergent wetland plant communities are evaluated for their response to global climate change (GCC), focusing on seagrasses, submerged freshwater plants, tidal marsh plants, freshwater marsh plants and mangroves. Similarities and differences are assessed in plant community responses to temperature increase, CO2increase, greater UV-B exposure, sea...

Changes in Hydrogen Content During Steelmaking

OpenAIRE

Vrbek K.; Lamut J.; Marolt M.; Knap M.

2015-01-01

Štore Steel produces steel grades for spring, forging and engineering industry applications. Steelmaking technology consists of scrap melting in Electric Arc Furnace (EAF), secondary metallurgy in Ladle Furnace (LF) and continuous casting of billets (CC). Hydrogen content during steelmaking of various steel grades and steelmaking technologies was measured. Samples of steel melt from EAF, LF and CC were collected and investigated. Sampling from Electric Arc Furnace and Ladle Furnace was carrie...

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. Copyright 2010 Elsevier B.V. All rights reserved.

Demonstration and Field Evaluation of Streambank Stabilization with Submerged Vanes

Science.gov (United States)

Whitman, H.; Hoopes, J.; Poggi, D.; Fitzpatrick, F.; Walz, K.; ,

2001-01-01

The effectiveness of submerged vanes for reducing bank erosion and improving aquatic habitat is being evaluated at a site on North Fish Creek, a Lake Superior tributary. Increased runoff from agricultural areas with clayey soils has increased flood magnitudes and the erosion potential/transport capacity of the stream. Most of the creek's sediment load originates from the erosion of 17 large bluffs. This creek contains important recreational fisheries that are potentially limited by the loss of aquatic habitat from deposition of sediment on spawning beds. Submerged vanes are a cost effective and environmentally less intrusive alternative to traditional structural stabilization measures. Submerged vanes protrude from a channel bed, are oriented at an angle to the local velocity, and are distributed along a portion of channel. They induce a transverse force and torque on the flow along with longitudinal vortexes that alter the cross sectional shape and alignment of the channel. Submerged vanes were installed at a bluff/bend site in summer and fall 2000. The number, size, and layout of the vanes were based upon the channel morphology under estimated bankfull conditions. The effectiveness of the vanes will be evaluated by comparing surveys of the bluff face, streamflow, and channel conditions for several years after installation of the submerged vanes with surveys before and immediately after their installation.

Fuel sparing: Control of industrial furnaces using process gas as supplemental fuel

International Nuclear Information System (INIS)

Boisvert, Patrick G.; Runstedtler, Allan

2014-01-01

Combustible gases from industrial processes can be used to spare purchased fuels such as natural gas and avoid wasteful flaring of the process gases. One of the challenges of incorporating these gases into other furnaces is their intermittent availability. In order to incorporate the gases into a continuously operating furnace, the furnace control system must be carefully designed so that the payload is not affected by the changing fuel. This paper presents a transient computational fluid dynamics (CFD) model of an industrial furnace that supplements natural gas with carbon monoxide during furnace operation. A realistic control system of the furnace is simulated as part of the CFD calculation. The time dependent changes in fuels and air injection on the furnace operation is observed. It is found that there is a trade-off between over-controlling the furnace, which results in too sensitive a response to normal flow oscillations, and under-controlling, which results in a lagged response to the fuel change. - Highlights: •Intermittently available process gases used in a continuously operating furnace. •Study shows a trade-off between over-controlling and under-controlling the furnace. •Over-controlling: response too sensitive to normal flow oscillations. •Under-controlling: lagged response to changing fuel composition. •Normal flow oscillations in furnace would not be apparent in steady-state model

10 CFR 431.72 - Definitions concerning commercial warm air furnaces.

Science.gov (United States)

2010-01-01

... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial warm air furnaces. 431... CERTAIN COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Warm Air Furnaces § 431.72 Definitions concerning commercial warm air furnaces. The following definitions apply for purposes of this subpart D, and of subparts...

A direct, single-step plasma arc-vitreous ceramic process for stabilizing spent nuclear fuels, sludges, and associated wastes

International Nuclear Information System (INIS)

Feng, X.; Einziger, R.E.; Eschenbach, R.C.

1997-01-01

A single-step plasma arc-vitreous ceramic (PAVC) process is described for converting spent nuclear fuel (SNF), SNF sludges, and associated wastes into a vitreous ceramic waste form. This proposed technology is built on extensive experience of nuclear waste form development and nuclear waste treatment using the commercially available plasma arc centrifugal (PAC) system. SNF elements will be loaded directly into a PAC furnace with minimum additives and converted into vitreous ceramics with up to 90 wt% waste loading. The vitreous ceramic waste form should meet the functional requirements for borosilicate glasses for permanent disposal in a geologic repository and for interim storage. Criticality safety would be ensured through the use of batch modes, and controlling the amount of fuel processed in one batch. The minimum requirements on SNF characterization and pretreatment, the one-step process, and minimum secondary waste generation may reduce treatment duration, radiation exposure, and treatment cost

TECHNOLOGICAL PECULIARITIES O F MELTING AND OUT-OF-FURNACE PROCESSING OF BALANCED STEELS IN CONDITIONS OF ELECTRIC FURNACE STEELMAKING AND CONTINUOUS CASTING

Directory of Open Access Journals (Sweden)

S. V. Terletski

2007-01-01

Full Text Available The technological peculiarities of melting and out-of-furnace processing of balanced steels in conditions of electric furnace steelmaking and continuous cast of RUP “BMZ” are considered.

Multiphase flow modelling of furnace tapholes

OpenAIRE

Reynolds, Quinn G.; Erwee, Markus W.

2017-01-01

Pyrometallurgical furnaces of many varieties make use of tapholes in order to facilitate the removal of molten process material from inside the vessel. Correct understanding and operation of the taphole is essential for optimal performance of such furnaces. The present work makes use of computational fluid dynamics models generated using the OpenFOAM® framework in order to study flow behaviour in the taphole system. Single-phase large-eddy simulation models are used to quantify the discharge ...

Submergence sensitivity of durum wheat, bread wheat and barley at the germination stage

Directory of Open Access Journals (Sweden)

Iduna Arduini

2016-06-01

Full Text Available Soil waterlogging at initial growth stages can cause heavy yield losses of winter cereals. Therefore, the screening for submergence tolerance traits in seeds of commercial varieties is of high concern worldwide. Ten Italian varieties of durum wheat (Triticum durum Desf., bread wheat (T. aestivum L. and barley (Hordeum vulgare L. were investigated for their ability to germinate in submerged conditions and to recover after submergence periods of three to 15 days. Submergence prevented germination and decreased germinability, at rates that increased with duration of submergence. Sensitivity ranked in the order: barley >durum wheat >bread wheat. We related the higher sensitivity of barley to its slower germination and slightly higher leakage of electrolytes, whereas the percentage of abnormal seedlings was lower than in other species. It was less than 4%, compared to less than 15 and 8% in durum wheat and bread wheat, respectively. Wide varietal differences were found in all species. According to variety, after 6-day submergence, germinability ranged from 2 to 42% in barley, from 5 to 80% in durum wheat, and from 30 to 77% in bread wheat. Varieties with more than 40% seed survival were three, six and seven per species, in the same order. The differential submergence sensitivity of varieties indicates a potential to select for waterlogging tolerance within Italian genotypes of winter cereal crops.

The Automation Control System Design of Walking Beam Heating Furnace

Directory of Open Access Journals (Sweden)

Hong-Yu LIU

2014-10-01

Full Text Available Combining the transformation project of certain strip steel rolling production line, the techniques process of walking beam heating furnace was elaborated in this paper. The practical application of LOS-T18-2ZC1 laser detector was elaborated. The network communication model of walking beam heating furnace control system was designed. The realization method of production process automation control was elaborated. The entire automation control system allocation picture and PLC power distribution system picture of walking beam heating furnace were designed. Charge machine movement process was elaborated. Walking beam movement process was elaborated. Extractor movement process was elaborated. The hydraulic station of walking mechanism was elaborated. Relative control circuit diagram was designed. The control function of parallel shift motor, uplifted and degressive motor was elaborated. The control circuit diagram of parallel shift motor of charge machine and extractor of first heating furnace was designed. The control circuit diagram of uplifted and degressive motor of charge machine and extractor of first heating furnace was designed. The realization method of steel blank length test function was elaborated. The realization method of tracking and sequence control function of heating furnace field roller were elaborated. The design provides important reference base for enhancing walking beam heating furnace control level.

Modeling of aerodynamics in vortex furnace

Energy Technology Data Exchange (ETDEWEB)

Anufriev, I.; Krasinsky, D. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Inst. of Thermophysics; Salomatov, V.; Anikin, Y.; Sharypov, O. [Russian Academy of Sciences, Novosibirsk (Russian Federation). Inst. of Thermophysics; Novosibirsk State Univ. (Russian Federation); Enkhjargal, Kh. [Mongol Univ. of Science and Technology, Ulan Bator (Mongolia)

2013-07-01

At present, the torch burning technology of pulverized-coal fuel in vortex flow is one of the most prospective and environmentally-friendly combustion technologies of low-grade coals. Appropriate organization of aerodynamics may influence stability of temperature and heat flux distributions, increase slag catching, and reduce toxic emissions. Therefore, from scientific point of view it is interesting to investigate aerodynamics in the devices aiming at justification of design and operating parameters for new steam generators with vortex furnace, and upgrade of existing boiler equipment. The present work is devoted to physical and mathematical modeling of interior aerodynamics of vortex furnace of steam generator of thermal power plants. Research was carried out on the air isothermal model which geometry was similar to one section of the experimental- industrial boiler TPE-427 of Novosibirsk TPS-3. Main elements of vortex furnace structure are combustion chamber, diffuser, and cooling chamber. The model is made from organic glass; on the front wall two rectangular nozzles (through which compressed air is injected) are placed symmetrically at 15 to the horizon. The Laser Doppler Velocimeter LAD-05 was used for non-contact measurement of vortex flow characteristics. Two velocity components in the XY-plane (in different cross- sections of the model) were measured in these experiments. Reynolds number was 3.10{sup 5}. Numerical simulation of 3-D turbulent isothermal flow was performed with the use of CFD package FLUENT. Detailed structure of the flow in vortex furnace model has been obtained in predictions. The distributions of main flow characteristics (pressure, velocity and vorticity fields, turbulent kinetic energy) are presented. The obtained results may be used at designing boilers with vortex furnace. Computations were performed using the supercomputer NKS-160.

46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or combustion... wall of a stayed furnace or combustion chamber, the defective portion of the plate shall be cut away...

Development and Validation of a 3-Dimensional CFB Furnace Model

Science.gov (United States)

Vepsäläinen, Arl; Myöhänen, Karl; Hyppäneni, Timo; Leino, Timo; Tourunen, Antti

At Foster Wheeler, a three-dimensional CFB furnace model is essential part of knowledge development of CFB furnace process regarding solid mixing, combustion, emission formation and heat transfer. Results of laboratory and pilot scale phenomenon research are utilized in development of sub-models. Analyses of field-test results in industrial-scale CFB boilers including furnace profile measurements are simultaneously carried out with development of 3-dimensional process modeling, which provides a chain of knowledge that is utilized as feedback for phenomenon research. Knowledge gathered by model validation studies and up-to-date parameter databases are utilized in performance prediction and design development of CFB boiler furnaces. This paper reports recent development steps related to modeling of combustion and formation of char and volatiles of various fuel types in CFB conditions. Also a new model for predicting the formation of nitrogen oxides is presented. Validation of mixing and combustion parameters for solids and gases are based on test balances at several large-scale CFB boilers combusting coal, peat and bio-fuels. Field-tests including lateral and vertical furnace profile measurements and characterization of solid materials provides a window for characterization of fuel specific mixing and combustion behavior in CFB furnace at different loads and operation conditions. Measured horizontal gas profiles are projection of balance between fuel mixing and reactions at lower part of furnace and are used together with both lateral temperature profiles at bed and upper parts of furnace for determination of solid mixing and combustion model parameters. Modeling of char and volatile based formation of NO profiles is followed by analysis of oxidizing and reducing regions formed due lower furnace design and mixing characteristics of fuel and combustion airs effecting to formation ofNO furnace profile by reduction and volatile-nitrogen reactions. This paper presents

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)

Combined electron beam and vacuum ARC melting for barrier tube shell material

International Nuclear Information System (INIS)

Worcester, S.A.; Woods, C.R.

1989-01-01

This patent describes a process of the type wherein zirconium tetrachloride is reduced to produce a metallic zirconium sponge. The sponge is distilled to generally remove residual magnesium and magnesium chloride, and the distilled sponge is melted to produce an ingot, the improvement for making a non-crystal bar material for use in lining the interior of zirconium alloy fuel element cladding which comprises: a. forming the distilled sponge into a consumable electrode; b. melting the consumable electrode in a multiple swept beam electron furnace with a feed rate between 1 and 20 inches per hour to form an intermediate ingot; and c. vacuum arc melting the intermediate ingot to produce a homogeneous final ingot, having 50-500 ppm iron

Alkali-activated blast furnace slag-zeolite cements and concretes

International Nuclear Information System (INIS)

Rakhimov, R.; Rakhimova, N.

2012-01-01

The aim of this work has been the study of alkali-activated slag-zeolite cements and concretes based on them. Various compositions have been tested and some characteristics such as the compressive strength have been measured versus zeolite additions. A table lists the specific surface area and particle size distributions of different cements. The conclusions of the study are the following. First, alkali-activated slag cements and concretes based on them are effective for immobilization of radioactive wastes and the production of building structures, designed for high radiation load. Secondly, zeolite-containing mineral additions are able to increase the immobilization capacity and radiation resistance of alkali-activated blast furnace slag cements and concretes. Thirdly, the efficiency of different zeolite-containing additions - 10% to increase alkali-activated blast furnace slag-zeolite cement strength was established. It is with alkaline components of water-glass, sodium carbonate, sodium sulphate. Fourth, the effective way of introducing zeolite additions in alkali-activated blast furnace slag-zeolite cement is inter-grinding of the slag and addition. Increase in strength of alkali-activated blast furnace slag-zeolite cement stone is 40% higher than that of the stone of a mixture of separately milled components. Fifth, Alkali-activated blast furnace slag-zeolite cements with zeolite-containing additions with a compressive strength of 10.1 to 140 MPa; alkali-activated blast furnace slag-zeolite cements mortars with compressive strength from 35.2 to 97.7 MPa; alkali-activated blast furnace slag-zeolite cements concretes with compressive strength up to 84.5 MPa and frost resistant up to 800 cycles were obtained

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.

Heat treatment of nuclear reactor pump part in integrated furnace facility

International Nuclear Information System (INIS)

Anon.

1983-01-01

A flexible heat treating system is meeting strict work specifications while accommodating the production flow pattern requirements and floor space needs of Advanced Metal Treating, Inc., Butler, Wis. Modular design and appropriate furnace configurations allow realization of the most efficient heat treat processing and energy use in a relatively small production area. The totally-integrated system (Pacemaker--manufactured by Lindberg, A Unit of General Signal, Chicago) consists of an electric integral-quench furnace with companion draw furnaces, washer unit and a material transfer car. With its one-side, inout configuration, the furnace operates with a minimum of drawing and washing equipment. The integral-quench furnace has a work chamber dimension of 30 by 48 by 30 inches (76.2 x 122 x 76.2 cm). The firm has two of these units, plus three in-out draw furnaces, one washer, one transfer car and two endothermic gas generators

Comparison of possibilities the blast furnace and cupola slag utilization by concrete production

Directory of Open Access Journals (Sweden)

D. Baricová

2010-04-01

Full Text Available In process of pig iron and cast iron production secondary raw materials and industrial wastes are formed The most abundant secondaryproduct originating in these processes are furnace slag. Blast furnace slag and cupola furnace slag originates from melting of gangue parts of metal bearing materials, slag forming additions and coke ash. In general, slag are compounds of oxides of metallic and non-metallic elements, which form chemical compounds and solutions with each other and also contain small volume of metals, sulfides of metals and gases. Chemical, mineralogical and physical properties of slag determinate their utilisation in different fields of industry.The paper presents results from the research of the blast furnace and cupola furnace slag utilization in the concrete production. Pilotexperiments of the concrete production were performed, by that the blast furnace and cupola furnace slag with a fractions of 0–4mm;4–8mm; 8–16mm were used as a natural substitute. A cupola furnace slag and combination of the blast furnace and cupola furnace slagwere used in the experiments. The analysis results show that such concretes are suitable for less demanding applications.

Non-polluting steam generators with fluidized-bed furnaces

Energy Technology Data Exchange (ETDEWEB)

Brandes, H [Deutsche Babcock A.G., Oberhausen (Germany, F.R.)

1979-07-01

The author reports on a 35 MW steam generator with hard coal fluidized-bed furnace a planned 35 MW steam generator with flotation-dirt fluidized-bed furnace, and on planned steam generators for fluidized-bed firing of hard coal up to a steam power of about 200 MW.

Modeling of Thermel Transport for GMAW

Directory of Open Access Journals (Sweden)

Aniruddha Ghosh

2012-01-01

Full Text Available Investigation of temperature distribution of submerged arc welded plates is essential while designing submerged arc welding joint because the key parameter for the change of weld bead geometry dimension, thermal stress, residual stress, tensile stress, hardness, and so forth is heat input, and heat input is the function of temperature distribution of GMAW process. An attempt is made in this paper to find out the exact solution of the thermal field induced in a semi-infinite body by a moving heat source with Gaussian distribution by selecting appropriate inside volume for submerged arc welding process. It has been revealed that for GMAW, best suitable heat source shape is a combination of semispherical and semioval.

Acclimation of a terrestrial plant to submergence facilitates gas exchange under water

DEFF Research Database (Denmark)

Mommer, L.; Pedersen, O.; Visser, E. J. W.

2004-01-01

Flooding imposes stress upon terrestrial plants since it severely hampers gas exchange rates between the shoot and the environment. The resulting oxygen deficiency is considered to be the major problem for submerged plants. Oxygen microelectrode studies have, however, shown that aquatic plants...... of this terrestrial plant species to submergence for gas exchange capacity is also shown. Shoot acclimation to submergence involved a reduction of the diffusion resistance to gases, which was not only functional by increasing diffusion of oxygen into the plant, but also by increasing influx of CO2, which enhances...... maintain relatively high internal oxygen pressures under water, and even may release oxygen via the roots into the sediment, also in dark. Based on these results, we challenge the dogma that oxygen pressures in submerged terrestrial plants immediately drop to levels at which aerobic respiration is impaired...

Metal accumulation by submerged macrophytes in eutrophic lakes at the watershed scale.

Science.gov (United States)

Xing, Wei; Wu, Haoping; Hao, Beibei; Liu, Guihua

2013-10-01

Metal concentrations (Al, Ba, Ca, K, Li, Mg, Na, Se, Sr and Ti) in submerged macrophytes and corresponding water and sediments were studied in 24 eutrophic lakes along the middle and lower reaches of the Yangtze River (China). Results showed that these eutrophic lakes have high metal concentrations in both water and sediments because of human activities. Average concentrations of Al and Na in tissues of submerged macrophytes were very high in sampled eutrophic lakes. By comparison, Ceratophyllum demersum and Najas marina accumulated more metals (e.g. Ba, Ca, K, Mg, Na, Sr and Ti). Strong positive correlations were found between metal concentrations in tissues of submerged macrophytes, probably because of co-accumulation of metals. The concentrations of Li, Mg, Na and Sr in tissues of submerged macrophytes significantly correlated with their corresponding water values, but not sediment values.

Effect of vacuum arc melting/casting parameters on shrinkage cavity/piping of austenitic stainless steel ingot

International Nuclear Information System (INIS)

Kamran, J.; Feroz, M.; Sarwar, M.

2009-01-01

Shrinkage cavity/piping at the end of the solidified ingot of steels is one of the most common casting problem in 316L austenitic stainless steel ingot, when consumable electrode is melted and cast in a water-cooled copper mould by vacuum arc re-melting furnace. In present study an effort has been made to reduce the size of shrinkage cavity/ piping by establishing the optimum value of hot topping process parameters at the end of the melting process. It is concluded that the shrinkage cavity/piping at the top of the solidified ingot can be reduced to minimum by adjusting the process parameters particularly the melting current density. (author)

Long-term allelopathic control of phytoplankton by the submerged macrophyte Elodea nuttallii

NARCIS (Netherlands)

Vanderstukken, M.; Declerck, S.A.J.; Decaestecker, E.; Muylaert, K.

2014-01-01

Keywords: allelochemicals; chemical ecology; competition; nutrient limitation; shallow lakes Summary 1.It is well known that submerged macrophytes can suppress phytoplankton blooms in lakes and thus promote water quality and biodiversity. One of the possible mechanisms through which submerged

Multi-fuel furnace. Demonstration project. Final rapport; Multibraendselsovn - Demonstrationsprojekt. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Dall Bentzen, J.

2012-06-15

It has been verified that the Dall Energy Furnace have unique features: - The furnace will accept biomass fuel with moisture content in range 20% to 60% and still keep the flue gas temperature within +-10 deg. Celsius (for pre-set temperature 900 to 975 deg. Celsius); - The ash quality from the furnace is very good with no excessive sintering and without carbon in the ash; - Flue gas dust content at the furnace exit is below 50 mg/Nm3, while the content of NO{sub x} and CO is below 175 mg/Nm3 and 20 mg/Nm3, respectively. The Dall Energy biomass furnace consists of two separate stages which are combined in a single aggregate: an updraft gasification process and a gas combustion process. As the furnace is refractory lined and as the furnace can operate at low excess air it is possible to burn biomass with water content above 60%. No mechanical parts are used at temperatures above 200 deg. Celsius. This provides a very rugged system. In the gasifier section a combustible gas is produced with a low velocity at the top of the gasifier bed. This gas is combusted to a flue gas with extremely low dust content. Also, the NO{sub x} and CO content is very low. The temperature of the flue gas at the exit is kept low by injecting water spray together with the secondary air. (Author)

Multikilowatt variable frequency microwave furnace

International Nuclear Information System (INIS)

Bible, D.W.; Lauf, R.J.; Everleigh, C.A.

1992-01-01

In this paper, the authors describe a new type of microwave processing furnace in which the frequency can be varied continuously from 4 to 8 GHz and the power level varied from zero up to 2.5 kW. The extraordinary bandwidth of this furnace is achieved by using a traveling wave tube (TWT) amplifier originally developed for electronic warfare applications. The TWT is a linear beam device characterized by a traveling electromagnetic wave that continuously extracts energy longitudinally along the path of an electron beam. The TWT, unlike other microwave tubes such as the magnetron, klystron, gyrotron, and others, does not depend upon resonant RF fields and is therefore capable of wide bandwidth operation.operation

Production and Physical Metallurgy of Pure Metals - Part V

Science.gov (United States)

1960-07-25

crucible . The essence of arc melting consists in the ignit- ion of an arc between the specimen placed in an intensively cooled copper crucible , and...water-cooled, and the cooling can be regulated by valves. -14- Universal laboratory arc furnace with cooled copper crucible : LOsend continued on next pag...furnaces by ordinary methods is very difficult and re- quires a fundamentally new method of melting. Such a method is arc melting in a water-cooled copper

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.

Application of a radiant heat transfer model to complex industrial reactive flows: combustion chambers, electric arcs; Application d`un modele de transfert radiatif a des ecoulements reactifs industriels complexes: chambres de combustion, arcs electriques

Energy Technology Data Exchange (ETDEWEB)

Mechitoua, N; Dalsecco, S; Delalondre, C; Simonin, O [Electricite de France (EDF), 78 - Chatou (France). Lab. National d` Hydraulique

1997-12-31

The direction of studies and researches (DER) of Electricite de France (EdF) has been involved for several years in a research program on turbulent reactive flows. The objectives of this program concern: the reduction of pollutant emissions from existing fossil-fueled power plants, the study of new production means (fluidized beds), and the promotion of electric power applications in the industry. An important part of this program is devoted to the development and validation of 3-D softwares and to the modeling of physical phenomena. This paper presents some industrial applications (furnaces, boilers, electric arcs) for which radiant heat transfers play an important role and the radiation models used. (J.S.) 8 refs.

Application of a radiant heat transfer model to complex industrial reactive flows: combustion chambers, electric arcs; Application d`un modele de transfert radiatif a des ecoulements reactifs industriels complexes: chambres de combustion, arcs electriques

Energy Technology Data Exchange (ETDEWEB)

Mechitoua, N.; Dalsecco, S.; Delalondre, C.; Simonin, O. [Electricite de France (EDF), 78 - Chatou (France). Lab. National d`Hydraulique

1996-12-31

The direction of studies and researches (DER) of Electricite de France (EdF) has been involved for several years in a research program on turbulent reactive flows. The objectives of this program concern: the reduction of pollutant emissions from existing fossil-fueled power plants, the study of new production means (fluidized beds), and the promotion of electric power applications in the industry. An important part of this program is devoted to the development and validation of 3-D softwares and to the modeling of physical phenomena. This paper presents some industrial applications (furnaces, boilers, electric arcs) for which radiant heat transfers play an important role and the radiation models used. (J.S.) 8 refs.

Clustering of arc volcanoes caused by temperature perturbations in the back-arc mantle.

Science.gov (United States)

Lee, Changyeol; Wada, Ikuko

2017-06-29

Clustering of arc volcanoes in subduction zones indicates along-arc variation in the physical condition of the underlying mantle where majority of arc magmas are generated. The sub-arc mantle is brought in from the back-arc largely by slab-driven mantle wedge flow. Dynamic processes in the back-arc, such as small-scale mantle convection, are likely to cause lateral variations in the back-arc mantle temperature. Here we use a simple three-dimensional numerical model to quantify the effects of back-arc temperature perturbations on the mantle wedge flow pattern and sub-arc mantle temperature. Our model calculations show that relatively small temperature perturbations in the back-arc result in vigorous inflow of hotter mantle and subdued inflow of colder mantle beneath the arc due to the temperature dependence of the mantle viscosity. This causes a three-dimensional mantle flow pattern that amplifies the along-arc variations in the sub-arc mantle temperature, providing a simple mechanism for volcano clustering.

A review of temperature measurement in the steel reheat furnace

International Nuclear Information System (INIS)

Martocci, A.P.; Mihalow, F.A.

1985-01-01

The incentive for conducting research and development on reheat furnaces is substantial; the domestic steel industry spent approximately one billion dollars on fuel in reheat furnaces in 1981. Bethlehem Steel Corp. spent /145 million of that total, and neither figure includes fuel consumed in soaking pits or annealing furnaces. If the authors set a goal to save 10% of these annual fuel costs, that translates into /100 million for the domestic steel industry and /14.5 million for Bethlehem Steel. These large sums of money are significant incentives. The purpose of this paper is to review the historical heating practices and equipment at steel reheat furnaces along with current practices and instrumentation

Topology optimization for submerged buoyant structures

NARCIS (Netherlands)

Picelli, R.; van Dijk, R.; Vicente, W.M.; Pavanello, R.; Langelaar, M.; van Keulen, A.

2017-01-01

This paper presents an evolutionary structural topology optimization method for the design of completely submerged buoyant modules with design-dependent fluid pressure loading. This type of structure is used to support offshore rig installation and pipeline transportation at all water depths. The

Lead scrap processing in rotary furnaces: a review

Energy Technology Data Exchange (ETDEWEB)

Rousseau, M

1987-01-01

Formerly, the lead scrap had been processed mainly in reverberatory and shaft furnaces or, even, in rotary furnaces (R.F.). The direct smelting of battery scrap entrains an expensive pollution control and high operating costs because of slag recirculation, coke consumption, losses in slag and matte. Nowadays, mechanized battery wrecking plants allow selective separation of casings and separators from metallic Pb (grids, poles, solders) as well as lead in non-metallic form (PbSO/sub 4/, PbO, PbO/sub 2/, contaminated with some Sb) frequently called paste. Because of their high performance and flexibility in metallurgical processing (melting, reducing, oxidizing and selective pouring) the R.F. supersedes the reverberatory furnace worldwide.

Development of spent solvent treatment process by a submerged combustion technique

International Nuclear Information System (INIS)

Uchiyama, Gunzo; Maeda, Mitsuru; Fujine, Sachio; Amakawa, Masayuki; Uchida, Katsuhide; Chida, Mitsuhisa

1994-01-01

An experimental study using a bench-scale equipment of 1 kg-simulated spent solvents per hour has been conducted in order to evaluate the applicability of a submerged combustion technique to the treatment of spent solvents contaminated with TRU elements. This report describes the experimental results on the combustion characteristics of the simulated spent solvents of tri-n-butyl phosphate and/or n-dodecane, and on the distribution behaviors of combustion products such as phosphoric acid, Ru, I, Zr and lanthanides as TRU simulants in the submerged combustion process. Also the experimental results of TRU separation from phosphoric acid solution by co-precipitation using bismuth phosphate are reported. It was shown that the submerged combustion technique was applicable to the treatment of spent solvents including the distillation residues of the solvent. Based on the experimental data, a new treatment process of spent solvent was proposed which consisted of submerged combustion, co-precipitation using bismuth phosphate, ceramic membrane filtration, cementation of TRU lean phosphate, and vitrification of TRU rich waste. (author)

Pump Coastdown with the Submerged Flywheel

Energy Technology Data Exchange (ETDEWEB)

Yoon, Hyun-Gi; Seo, KyoungWoo; Kim, Seong Hoon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

Many research reactors are generally designed as open pool types in consideration of the heat removal of the nuclear fuels, reactor operation and accessibility. Reactor structure assembly is generally placed at the pool bottom as shown in Fig. 1. Primary cooling system pump circulates the coolant from the reactor structure to the heat exchanger in order to continuously remove the heat generated from the reactor core in the research reactor as shown in Fig. 1. The secondary cooling system releases the transferred heat to the atmosphere by the cooling tower. Coastdown flow rate of the primary cooling system pump with the submerged flywheel are calculated analytically in case of the accident situation. Coastdown flow rate is maintained until almost 80 sec when the pump stops normally. But, coastdown flow rate is rapidly decreased when the flywheel is submerged because of the friction load on the flywheel surface.

Influence of direct reduced iron on the energy balance of the electric arc furnace in steel industry

International Nuclear Information System (INIS)

Kirschen, Marcus; Badr, Karim; Pfeifer, Herbert

2011-01-01

A model of the EAF energy efficiency was developed based on a closed mass and energy balance of the EAF melting process. This model was applied to industrial EAFs in steel industry charged with scrap or with mixes of scrap and DRI. Complex mass and energy conversion in the EAF was simplified with the introduction of mass and energy conversion efficiencies for the conversion of oxygen and the energy conversion of electrical energy in the electric arcs, chemical energy from the oxidation reactions in the melt and energy from the combustion of burner gas. It turned out that close agreement with observed process parameters from 16 EAFs is obtained by slight variations of the efficiency values. Especially the sensitivity of the steel temperature from the energy conversion efficiency of the electric arc energy indicates the importance of efficient foaming slag operation in EAF steel making. Characteristics and process parameters of DRI charged EAFs are discussed. Model results for a series of case studies illustrate the correlations between DRI chemical composition, DRI portion, oxygen consumption, etc. with electrical energy demand in order to indentify cost-effective EAF process conditions. -- Highlights: → Energy demand and carbon dioxide emission figures of EAF steelmaking processes based on steel scrap and DRI. → Complete energy balance of the EAF process using various input materials. → Application of the model to industrial EAF in steel industry in 4 case studies and discussion of model results. → Comparison with other models, critical discussion.

Influence of Microalgae onto submerged surfaces on Fouling

Science.gov (United States)

Kong, M.; Eom, C.; Yoon, B.; Yoon, H.; Kim, B.; Chung, K.

2012-12-01

Lots of algae together with organic matter deposited on the submerged surface can be easily observed occurring in the shallower water along the coast. This is mainly because only those organisms with the ability to adapt to the new situations created by man can firmly adhere enough to avoid being washed off. Chemical and microbiological characteristics of the fouling microalgae developed on various surfaces in contact with the seawater were made. The microbial compositions of the microalgae formed on the submerged surfaces were tested for. The quantities of the diverse microalgae in the samples developed on the prohibiting submerged surface were larger when there was no concern about materials for special selection for fouling. To confirm formation of microalgae on adsorbents was done SEM-EDS (Scanning Electron Microscope-Spectrometer) analysis. Microbial identified using optical microscope. In addition to, we quantified attaching microalgae as pass time. Experiment results, ten species which are Nitzshhia sp., Eucampia sp., Coscinodiscus sp., Licmophora sp., Rhizosolenia sp., Cylindrotheca sp., Striateela sp., Thalassionema sp., Guinardia sp., and Helicostomella sp. discovered to reservoir formed biofouling. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater.

Rice SUB1A constrains remodeling of the transcriptome and metabolome during submergence and post-submergence recovery”.

Science.gov (United States)

The rice (Oryza sativa L.) ethylene-responsive transcription factor SUB1A confers tolerance to prolonged, complete submergence by limiting underwater elongation growth. Rice encoding SUB1A-1 also recovers photosynthetic function and re-commences development towards flowering more rapidly after desu...

An ultrasonic method for separation of epiphytic microbes from freshwater submerged macrophytes.

Science.gov (United States)

Cai, Xianlei; Gao, Guang; Yang, Jing; Tang, Xiangming; Dai, Jiangyu; Chen, Dan; Song, Yuzhi

2014-07-01

Epiphytic microbes are common inhabitants of freshwater submerged macrophytes, which play an important role in aquatic ecosystems. An important precondition for studying the epiphytic microbes is having an effective method of separating the attached microbes from the host macrophytes. We developed an ultrasound-based method for separating epiphytic microbes from freshwater submerged macrophytes, optimized the conditions of ultrasonic separation with an orthogonal experimental design, and compared the optimized ultrasonic method with manual separation. This method can be particularly useful for freshwater submerged macrophytes having a complex morphology. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Process simulation and uncertainty analysis of plasma arc mixed waste treatment

International Nuclear Information System (INIS)

Ferrada, J.J.; Welch, T.D.

1994-01-01

Innovative mixed waste treatment subsystems have been analyzed for performance, risk, and life-cycle cost as part of the U.S. Department of Energy's (DOE)'s Mixed Waste Integrated Program (MWIP) treatment alternatives development and evaluation process. This paper concerns the analysis of mixed waste treatment system performance. Performance systems analysis includes approximate material and energy balances and assessments of operability, effectiveness, and reliability. Preliminary material and energy balances of innovative processes have been analyzed using FLOW, an object-oriented, process simulator for waste management systems under development at Oak Ridge National Laboratory. The preliminary models developed for FLOW provide rough order-of-magnitude calculations useful for sensitivity analysis. The insight gained from early modeling of these technologies approximately will ease the transition to more sophisticated simulators as adequate performance and property data become available. Such models are being developed in ASPEN by DOE's Mixed Waste Treatment Project (MWTP) for baseline and alternative flow sheets based on commercial technologies. One alternative to the baseline developed by the MWIP support groups in plasma arc treatment. This process offers a noticeable reduction in the number of process operations as compared to the baseline process because a plasma arc melter is capable of accepting a wide variety of waste streams as direct inputs (without sorting or preprocessing). This innovative process for treating mixed waste replaces several units from the baseline process and, thus, promises an economic advantage. The performance in the plasma arc furnace will directly affect the quality of the waste form and the requirements of the off-gas treatment units. The ultimate objective of MWIP is to reduce the amount of final waste produced, the cost, and the environmental impact

Critical Length Criterion and the Arc Chain Model for Calculating the Arcing Time of the Secondary Arc Related to AC Transmission Lines

International Nuclear Information System (INIS)

Cong Haoxi; Li Qingmin; Xing Jinyuan; Li Jinsong; Chen Qiang

2015-01-01

The prompt extinction of the secondary arc is critical to the single-phase reclosing of AC transmission lines, including half-wavelength power transmission lines. In this paper, a low-voltage physical experimental platform was established and the motion process of the secondary arc was recorded by a high-speed camera. It was found that the arcing time of the secondary arc rendered a close relationship with its arc length. Through the input and output power energy analysis of the secondary arc, a new critical length criterion for the arcing time was proposed. The arc chain model was then adopted to calculate the arcing time with both the traditional and the proposed critical length criteria, and the simulation results were compared with the experimental data. The study showed that the arcing time calculated from the new critical length criterion gave more accurate results, which can provide a reliable criterion in term of arcing time for modeling and simulation of the secondary arc related with power transmission lines. (paper)

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.

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)

Design of a rotating-hearth furnace

Energy Technology Data Exchange (ETDEWEB)

Behrens, H A [LOI Industrieofenanlagen G.m.b.H., Essen (Germany, F.R.)

1979-09-01

Part I of this paper is intended to present a review of the theory of heating round stock of a length considerably exceeding the diameter. It is permissible to neglect heating from the ends of the cylinders. With short and thick ingots as used in pilgrim mills, for instance, such simplification is not possible. The method for calculating the waste gas temperature can also be used for the remaining furnace sections provided certain conditions are allowed for and computational procedures observed. Part II of the paper will deal with this and with the major design features of rotating-hearth furnaces.

Arc saw development report

International Nuclear Information System (INIS)

Deichelbohrer, P.R.; Beitel, G.A.

1981-01-01

The arc saw is one of the key components of the Contaminated Equipment Volume Reduction (CEVR) Program. This report describes the progress of the arc saw from its inception to its current developmental status. History of the arc saw and early contributors are discussed. Particular features of the arc saw and their advantages for CEVR are detailed. Development of the arc saw including theory of operation, pertinent experimental results, plans for the large arc saw and advanced control systems are covered. Associated topics such as potential applications for the arc saw and other arc saw installations in the world is also touched upon

Application of submerged induction hardening; Ekichu koshuha yakiire no jitsuyoka

Energy Technology Data Exchange (ETDEWEB)

Nishimori, Y; Nagai, Y; Amii, Y [Mazda Motor Corp., Hiroshima (Japan); Tanaka, Y [Netsuren Co. Ltd., Tokyo (Japan); Mizuma, T [Toyo Advanced Technologies Co. Ltd., Hiroshima (Japan)

1997-10-01

As a cost-cutting measure, the linerless diesel engine was adopted by applying submerged induction hardening process which can harden partial inner surface of cylinder block bore. In applying this process, (1) development of induction coil which can form any shape of quenched pattern and (2) the development of machining technology which can hone precisely the distorted bore after quenching, were important. With these improvements, submerged Induction hardening was made practical. 1 ref., 11 figs.

Auroral arc classification scheme based on the observed arc-associated electric field pattern

International Nuclear Information System (INIS)

Marklund, G.

1983-06-01

Radar and rocket electric field observations of auroral arcs have earlier been used to identify essentially four different arc types, namely anticorrelation and correlation arcs (with, respectively, decreased and increased arc-assocaited field) and asymmetric and reversal arcs. In this paper rocket double probe and supplementary observations from the literature, obtained under various geophysical conditions, are used to organize the different arc types on a physical rather than morphological basis. This classification is based on the relative influence on the arc electric field pattern from the two current continuity mechanisms, polarisation electric fields and Birkeland currents. In this context the tangential electric field plays an essential role and it is thus important that it can be obtained with both high accuracy and resolution. In situ observations by sounding rockets are shown to be better suited for this specific task than monostatic radar observations. Depending on the dominating mechanism, estimated quantitatively for a number of arc-crossings, the different arc types have been grouped into the following main categories: Polarisation arcs, Birkeland current arcs and combination arcs. Finally the high altitude potential distributions corresponding to some of the different arc types are presented. (author)

Reports on research achievements in developing high-performance industrial furnaces in fiscal 1998 (Research and development of high-performance industrial furnaces). Volume 1; 1998 nendo koseino kogyoro nado ni kansuru kenkyu kaihatsu seika hokokusho. 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

From the reports on research achievements in developing high-performance industrial furnaces in fiscal 1998, the report volume 1 was prepared as a research achievement report of each working group, detailing fundamental researches, heating furnaces, and heat treatment furnaces. The fundamental researches have researched combustion evaluating technology, characteristics of the area in the vicinity of a combustor, characteristics of combustion of high-temperature air, heating characteristics of a furnace to investigate effect of local heat absorption, and combustion evaluation. For the heating furnaces, the following subjects were studied: development of an in-furnace combustion model, summary of an experiment for evaluating high-temperature air combustion, furnace height relative to combustion heat transfer characteristics, heat loss minimizing technology, combustion heat transfer characteristics of liquid fuels, optimal operation of the high-temperature air combustion, basic control in heating control, and steel piece heating control. Studies were performed for the heat treatment furnaces on the case of a direct firing furnace in evaluating the heat transfer characteristics, the case of a radiant tube furnace, application of thermal fluid simulation technology, furnace averaging technology, soot reducing technology, control technology, and trial design on a high-performance heat treatment furnace. (NEDO)

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.

Across-arc versus along-arc Sr-Nd-Pb isotope variations in the Ecuadorian volcanic arc

Science.gov (United States)

Ancellin, Marie-Anne; Samaniego, Pablo; Vlastélic, Ivan; Nauret, François; Gannoun, Adbelmouhcine; Hidalgo, Silvana

2017-03-01

Previous studies of the Ecuadorian arc (1°N-2°S) have revealed across-arc geochemical trends that are consistent with a decrease in mantle melting and slab dehydration away from the trench. The aim of this work is to evaluate how these processes vary along the arc in response to small-scale changes in the age of the subducted plate, subduction angle, and continental crustal basement. We use an extensive database of 1437 samples containing 71 new analyses, of major and trace elements as well as Sr-Nd-Pb isotopes from Ecuadorian and South Colombian volcanic centers. Large geochemical variations are found to occur along the Ecuadorian arc, in particular along the front arc, which encompasses 99% and 71% of the total variations in 206Pb/204Pb and 87Sr/86Sr ratios of Quaternary Ecuadorian volcanics, respectively. The front arc volcanoes also show two major latitudinal trends: (1) the southward increase of 207Pb/204Pb and decrease of 143Nd/144Nd reflect more extensive crustal contamination of magma in the southern part (up to 14%); and (2) the increase of 206Pb/204Pb and decrease of Ba/Th away from ˜0.5°S result from the changing nature of metasomatism in the subarc mantle wedge with the aqueous fluid/siliceous slab melt ratio decreasing away from 0.5°S. Subduction of a younger and warmer oceanic crust in the Northern part of the arc might promote slab melting. Conversely, the subduction of a colder oceanic crust south of the Grijalva Fracture Zone and higher crustal assimilation lead to the reduction of slab contribution in southern part of the arc.

Zone modelling of the thermal performances of a large-scale bloom reheating furnace

International Nuclear Information System (INIS)

Tan, Chee-Keong; Jenkins, Joana; Ward, John; Broughton, Jonathan; Heeley, Andy

2013-01-01

This paper describes the development and comparison of a two- (2D) and three-dimensional (3D) mathematical models, based on the zone method of radiation analysis, to simulate the thermal performances of a large bloom reheating furnace. The modelling approach adopted in the current paper differs from previous work since it takes into account the net radiation interchanges between the top and bottom firing sections of the furnace and also allows for enthalpy exchange due to the flows of combustion products between these sections. The models were initially validated at two different furnace throughput rates using experimental and plant's model data supplied by Tata Steel. The results to-date demonstrated that the model predictions are in good agreement with measured heating profiles of the blooms encountered in the actual furnace. It was also found no significant differences between the predictions from the 2D and 3D models. Following the validation, the 2D model was then used to assess the impact of the furnace responses to changing throughput rate. It was found that the potential furnace response to changing throughput rate influences the settling time of the furnace to the next steady state operation. Overall the current work demonstrates the feasibility and practicality of zone modelling and its potential for incorporation into a model based furnace control system. - Highlights: ► 2D and 3D zone models of large-scale bloom reheating furnace. ► The models were validated with experimental and plant model data. ► Examine the transient furnace response to changing the furnace throughput rates. ► No significant differences found between the predictions from the 2D and 3D models.

Blast furnace hearth lining: post mortem analysis

International Nuclear Information System (INIS)

Almeida, Bruno Vidal de; Vernilli Junior, Fernando

2017-01-01

The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 deg C for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair of this furnace. The samples were collected from different parts of the hearth lining and characterized using the following techniques: Bulk Density and Apparent Porosity, X-Ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy with Energy-dispersive X-Ray Spectroscopy. The results showed that the carbon blocks located at the opposite side of the blast furnace tap hole kept its main physicochemical characteristics preserved even after the production of 20x10"6 ton of hot metal. However, the carbon blocks around the Tap Hole showed infiltration by hot metal and slag and it presents a severe deposition of zinc and sulfur over its carbon flakes. The presence of these elements is undesired because it reduces the physic-chemical stability of this refractory system. This deposition found in the carbon refractory is associated with impurities present in the both coke and the sinter feed used in this blast furnace in the last few years. (author)

Blast furnace hearth lining: post mortem analysis

Energy Technology Data Exchange (ETDEWEB)

Almeida, Bruno Vidal de; Vernilli Junior, Fernando, E-mail: bva@usp.br [Universidade de Sao Paulo (USP), Lorena, SP (Brazil). Escola de Engenharia; Neves; Elton Silva; Silva, Sidiney Nascimento [Companhia Siderugica Nacional (CSN), Rio de Janeiro, RJ (Brazil)

2017-05-15

The main refractory lining of blast furnace hearth is composed by carbon blocks that operates in continuous contact with hot gases, liquid slag and hot metal, in temperatures above 1550 deg C for 24 hours a day. To fully understand the wear mechanism that acts in this refractory layer system it was performed a Post Mortem study during the last partial repair of this furnace. The samples were collected from different parts of the hearth lining and characterized using the following techniques: Bulk Density and Apparent Porosity, X-Ray Fluorescence, X-ray Diffraction, Scanning Electron Microscopy with Energy-dispersive X-Ray Spectroscopy. The results showed that the carbon blocks located at the opposite side of the blast furnace tap hole kept its main physicochemical characteristics preserved even after the production of 20x10{sup 6} ton of hot metal. However, the carbon blocks around the Tap Hole showed infiltration by hot metal and slag and it presents a severe deposition of zinc and sulfur over its carbon flakes. The presence of these elements is undesired because it reduces the physic-chemical stability of this refractory system. This deposition found in the carbon refractory is associated with impurities present in the both coke and the sinter feed used in this blast furnace in the last few years. (author)

Waterlogging and submergence: surviving poor aeration

NARCIS (Netherlands)

Atwell, B.J.; Ismail, A.M.; Pedersen, O.; Shabala, S.; Sorrell, B.; Voesenek, Laurentius|info:eu-repo/dai/nl/074850849

2014-01-01

Flooding, resulting in soil waterlogging and in many situations even complete submergence of plants, is an important abiotic stress in many regions worldwide. The number of floods has increased in recent decades (Figure 18.1), and the severity of floods is expected to increase further in many

Energy conservation in industrial furnaces with vertical radiation roofs of reinforced refractory concrete

Energy Technology Data Exchange (ETDEWEB)

Grafe, E

1981-01-01

The paper discusses static systems for furnaces of reinforced refractory concrete, the temperature field over the finned-plate cross section, the calculation of the reinforced refractory concrete, experimental application in a flat open-hearth pusher furnace, a pack heating furnace, and a sinker furnace. There are cantilever beam plates, frames, and drop ceiling elements particularly suited for efficient use of high-performance burners.

Differential Response of Floating and Submerged Leaves of Longleaf Pondweed to Silver Ions

Directory of Open Access Journals (Sweden)

Nisha Shabnam

2017-06-01

Full Text Available In this study, we have investigated variations in the potential of floating and submerged leaves of longleaf pondweed (Potamogeton nodosus to withstand silver ion (Ag+-toxicity. Both floating and submerged leaves changed clear colorless AgNO3 solutions to colloidal brown in the presence of light. Transmission electron microscopy revealed the presence of distinct crystalline Ag-nanoparticles (Ag-NPs in these brown solutions. Powder X-ray diffraction pattern showed that Ag-NPs were composed of Ag0 and Ag2O. Photosystem (PS II efficiency of leaves declined upon exposure to Ag+ with a significantly higher decline in the submerged leaves than in the floating leaves. Similarly, Ag+ treatment caused a significant reduction in the carboxylase activity of the ribulose bisphosphate carboxylase/oxygenase in leaves. The reduction in this carboxylase activity was significantly higher in the submerged than in the floating leaves. Ag+ treatment also resulted in a significant decline in the levels of non-enzymatic and enzymatic antioxidants; the decline was significantly lower in the floating than in submerged leaves. X-ray photoelectron spectroscopy revealed the presence of Ag2O in these leaves. Inductively coupled plasma mass spectrometry analysis revealed a three-fold higher Ag content in the submerged than in floating leaves. Our study demonstrates that floating leaves of longleaf pondweed have a superior potential to counter Ag+-toxicity compared with submerged leaves, which could be due to superior potential of floating leaves to reduce Ag+ to less/non-toxic Ag0/Ag2O-nanoparticles/nanocomplexes. We suggest that modulating the genotype of longleaf pondweed to bear higher proportion of floating leaves would help in cleaning fresh water bodies contaminated with ionic forms of heavy metals.

Influence of arc current and pressure on non-chemical equilibrium air arc behavior

Science.gov (United States)

Yi, WU; Yufei, CUI; Jiawei, DUAN; Hao, SUN; Chunlin, WANG; Chunping, NIU

2018-01-01

The influence of arc current and pressure on the non-chemical equilibrium (non-CE) air arc behavior of a nozzle structure was investigated based on the self-consistent non-chemical equilibrium model. The arc behavior during both the arc burning and arc decay phases were discussed at different currents and different pressures. We also devised the concept of a non-equilibrium parameter for a better understanding of non-CE effects. During the arc burning phase, the increasing current leads to a decrease of the non-equilibrium parameter of the particles in the arc core, while the increasing pressure leads to an increase of the non-equilibrium parameter of the particles in the arc core. During the arc decay phase, the non-CE effect will decrease by increasing the arc burning current and the nozzle pressure. Three factors together—convection, diffusion and chemical reactions—influence non-CE behavior.

Continuous austempering fluidized bed furnace. Final report

Energy Technology Data Exchange (ETDEWEB)

Srinivasan, M.N. [Lamar Univ., Beaumont, TX (United States). Dept. of Mechanical Engineering

1997-09-23

The intended objective of this project was to show the benefits of using a fluidized bed furnace for austenitizing and austempering of steel castings in a continuous manner. The division of responsibilities was as follows: (1) design of the fluidized bed furnace--Kemp Development Corporation; (2) fabrication of the fluidized bed furnace--Quality Electric Steel, Inc.; (3) procedure for austempering of steel castings, analysis of the results after austempering--Texas A and M University (Texas Engineering Experiment Station). The Department of Energy provided funding to Texas A and M University and Kemp Development Corporation. The responsibility of Quality Electric Steel was to fabricate the fluidized bed, make test castings and perform austempering of the steel castings in the fluidized bed, at their own expense. The project goals had to be reviewed several times due to financial constraints and technical difficulties encountered during the course of the project. The modifications made and the associated events are listed in chronological order.

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.

Loss on Ignition Furnace Acceptance and Operability Test Procedure

International Nuclear Information System (INIS)

JOHNSTON, D.C.

2000-01-01

The purpose of this Acceptance Test Procedure and Operability Test Procedure (ATP/OTP)is to verify the operability of newly installed Loss on Ignition (LOI) equipment, including a model 1608FL CMTM 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 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 expected airflow of 100 to 125 cubic feet per minute (cfm) through the inlet filter. The glovebox inlet G1 filter will be 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

Effects of submergence on growth and survival of saplings of three wetland trees differing in adaptive mechanisms for flood tolerance

Directory of Open Access Journals (Sweden)

Fumiko Iwanaga

2015-04-01

Full Text Available Aim of study: Withstanding total submergence and reaeration following submergence is essential for the survival and establishment of wetland species. We focused on “LOES–low oxygen escape syndrome” and “LOQS–low oxygen quiescence syndrome” and compared tolerances to total submergence among wetland woody species differing in morphological adaptation to soil flooding. Area of study, materials and methods: This study examined the survival of 2-year-old saplings of Taxodium distichum and Metasequioia glyptostroboides (LOQS species, and Alnus japonica (LOES species, during and after total submergence. Saplings were completely submerged, then de-submerged to determine trends in survival and growth Main results: The M. glyptostroboides and A. japonica saplings could not survive prolonged submergence for more than 8 weeks, whereas saplings of T. distichum survived for over 2 years. Submerged saplings of all species showed no significant growth or modifications in morphology and anatomy under water, such as shoot elongation, adventitious root formation, and/or aerenchyma development. All T. distichum saplings that were de-submerged in the second year had the same pattern of shoot growth regardless of differences in timing and seasonality of de-submergence. Wood formation in T. distichum saplings ceased during submergence and resumed after de-submergence in spring and summer, but not in autumn. Research highlights: T. distichum saplings, which survived longer submergence periods than A. japonica and M. glyptostroboides, had physiological characteristics, such as suspension of growth and metabolism, which allowed survival of protracted total submergence (at least 2 years when saplings were immersed during the dormant stage before leaf flushing.

INFLUENCE OF STRUCTURAL PARAMETERS OF LOW-CARBON STEEL ON ELECTRIC ARC BURNING

Directory of Open Access Journals (Sweden)

I. O. Vakulenko

2017-10-01

Full Text Available Purpose. The article is aimed to evaluate the influence of structural parameters of low-carbon steel on arcing process. Methodology. The values of the micro- and substructure characteristics of the electrode wire metal were changed by varying the parameters of heat treatment and cold deformation by drawing. The degree of plastic deformation was obtained by drawing blanks from different initial diameter to final dimension of 1 mm. The thermal treatment was carried out in electric chamber furnace of the SNOL-1,6.2,5.1/11-IZ type. The temperature was measured by chromel-alumel thermocouple and the electromotive force was determined using the DC potentiometer. In order to obtain the substructure of different dispersion degree the steel (after quenching from temperatures and tempering at 650°C for 1 hour was subjected to cold drawing to reduction 17 – 80%. To form structure with different ferrite grain size the steel after drawing was annealed at 680°C for 1 hour. The microstructure was examined under a light and electron transmission microscope UEMV-100K at the accelerating voltage 100 kV. The grain and subgrain sizes were evaluated using the methodologies of quantitative metallography. A welding converter of the PSG-500 type was used to study the arc welding process of direct and reverse polarities. Findings. The experimentally detected value of the welding current, which depends on the degree of deformation during wire drawing, under conditions of stable arc burning of direct polarity is about an order of magnitude lower than the calculated value. Similar difference was found for the arc of reverse polarity: the experimental value of the welding current is 5...6 times less than the calculated value. Dependence analysis shows that, regardless of the polarity of the welding arc, a good enough agreement between the calculated and experimental values of the welding current is limited to deformations of 60%. For deformation degrees of more than 60

Development of a cylindrical gas-fired furnace for reycling ...

African Journals Online (AJOL)

This study presents the development of a cylindrical gas-fired furnace, which could be used for recycling aluminum in small-scale foundries in Nigeria. The crucible, combustion chamber, suspension shaft and bearings were appropriately sized. The furnace chamber was 410 mm high and 510 mm diameter and had a ...

Application of roof radiant burners in large pusher-type furnaces

Directory of Open Access Journals (Sweden)

A. Varga

2009-07-01

Full Text Available The paper deals with the application of roof flat-flame burners in the pusher-type steel slab reheating furnaces, after furnace reconstruction and replacement of conventional torch burners, with the objective to increase the efficiency of radiative heat transfer from the refractory roof to the charge. Based on observations and on measurements of the construction and process parameters under operating conditions, the advantages and disadvantages of indirectly oriented radiant heat transfer are analysed in relation to the heat transfer in classically fired furnaces.

Applying the seedling-emergence method under waterlogged conditions to detect the seed bank of aquatic plants in submerged sediments

NARCIS (Netherlands)

Boedeltje, G; ter Heerdt, GNJ; Bakker, JP

Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings

Unique furnace system for high-energy-neutron experiments

International Nuclear Information System (INIS)

Panayotou, N.F.; Green, D.R.; Price, L.S.

1982-03-01

The low flux of high energy neutron sources requires optimum utilization of the available neutron field. A furnace system has been developed in support of the US DOE fusion materials program which meets this challenge. Specimens positioned in two temperature zones just 1 mm away from the outside surface of a neutron window in the furnace enclosure can be irradiated simultaneously at two independent, isothermal (+- 1 0 C) temperatures. The temperature difference between these closely spaced isothermal zones is controllable from 0 to 320 0 C and the maximum temperature is 400 0 C. The design of the system also provides a controlled specimen environment, rapid heating and cooling and easy access to heaters and thermocouples. This furnace system is in use at the Rotating Target Neutron Source-II of Lawrence Livermore National Laboratory

Handling of corn stover bales for combustion in small and large furnaces

Energy Technology Data Exchange (ETDEWEB)

Morissette, R.; Savoie, P.; Villeneuve, J. [Agriculture and Agri-Food Canada, Quebec City, PQ (Canada)

2010-07-01

This paper reported on a study in which dry corn stover was baled and burned in 2 furnaces in the province of Quebec. Small and large rectangular bale formats were considered for direct combustion. The first combustion unit was a small 500,000 BTU/h dual chamber log wood furnace located at a hay growing farm in Neuville, Quebec. The heat was initially transferred to a hot water pipe system and then transferred to a hot air exchanger to dry hay bales. The small stover bales were placed directly into the combustion furnace. The low density of the bales compared to log wood, required filling up to 8 times more frequently. Stover bales produced an average of 6.4 per cent ash on a DM basis and required an automated system for ash removal. Combustion gas contained levels of particulate matter greater than 1417 mg/m{sup 3}, which is more than the local acceptable maximum of 600 mg/m{sup 3} for combustion furnaces. The second combustion unit was a high capacity 12.5 million BTU/h single chamber furnace located in Saint-Philippe-de-neri, Quebec. It was used to generate steam for a feed pellet mill. Large corn stover bales were broken up and fed on a conveyor and through a screw auger to the furnace. The stover was light compared to the wood chips used in this furnace. For mechanical reasons, the stover could not be fed continuously to the furnace.

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.

Acoustic Levitator With Furnace And Laser Heating

Science.gov (United States)

Barmatz, Martin B.; Stoneburner, James D.

1991-01-01

Acoustic-levitation apparatus incorporates electrical-resistance furnace for uniform heating up to temperature of about 1,000 degrees C. Additional local heating by pair of laser beams raise temperature of sample to more than 1,500 degrees C. High temperature single-mode acoustic levitator generates cylindrical-mode accoustic resonance levitating sample. Levitation chamber enclosed in electrical-resistance furnace. Infrared beams from Nd:YAG laser provide additional local heating of sample. Designed for use in containerless processing of materials in microgravity or in normal Earth gravity.

Improvement of Photosynthesis by Sub1 QTL in Rice Under Submergence: Probed by Chlorophyll Fluorescence OJIP Transients

Directory of Open Access Journals (Sweden)

Panda Debabrata

2011-09-01

Full Text Available The influence of submergence on the photosynthetic activity in rice plants either possessing or not possessing Sub1 QTL i.e. Swarna and Swarna Sub1 cultivars (cv. were evaluated under simulated complete submergence. The leaf photosynthetic rate and stomatal conductance decreased in both the cv. during the progression of submergence as compared to control plant but significant varietal differences was observed after 1 day (d of submergence. Submergence also alters the photo-system (PS II activity, as reflected in a decrease in the values of Fo, Fm and the Fv/Fm ratio and degradation of chlorophyll, more in Swarna than that of Swarna Sub1. Under complete submergence the shape of the OJIP transient also changed in rice leaves with decrease in maximal fluorescence (P=Fm intensity, resulted lowering of variable fluorescence levels. The decrease was more pronounced in Swarna compared to the Swarna Sub1 cv. Thus, Swarna Sub1 improves photosynthetic activity showing more photosynthetic rate compared to Swarna under submergence because, of less degradation of chlorophyll, higher stomatal conductance, and efficient PS II activity.

RBF–ARX model of an industrial furnace for drying olive pomace

International Nuclear Information System (INIS)

Casanova-Peláez, P.J.; Cruz-Peragón, F.; Palomar-Carnicero, J.M.; Dorado, R.; López-García, R.

2012-01-01

Highlights: ► We model a real furnace, fuelled with orujo, used to dry olive pomace. ► We apply a radial basic functions–auto-regression with exogenous variables (ARXs–RBFs) method. ► Root-mean-square error and r 2 are used to validate the ARX–RBF model. - Abstract: Drying operations are common in food industries. One of the main components in a drying system is the furnace. The furnace operation involves heat–mass transfer and combustion, thus it demands a complex mathematic representation. Since autoregressive methods are simple, and help to simulate rapidly a system, we model a drying furnace of olive pomace via an auto-regression with exogenous variables (ARXs) method. A neural network of radial basic functions (RBFs) defines the ARX experimental relation between the amounts of dry pomace (moisture content of 15%) used like fuel and the temperature of outlet gases. A real industrial furnace is studied to validate the proposed model, which can help to control the drying process.

Vegetative Propagule Pressure and Water Depth Affect Biomass and Evenness of Submerged Macrophyte Communities.

Science.gov (United States)

Li, Hong-Li; Wang, Yong-Yang; Zhang, Qian; Wang, Pu; Zhang, Ming-Xiang; Yu, Fei-Hai

2015-01-01

Vegetative propagule pressure may affect the establishment and structure of aquatic plant communities that are commonly dominated by plants capable of clonal growth. We experimentally constructed aquatic communities consisting of four submerged macrophytes (Hydrilla verticillata, Ceratophyllum demersum, Elodea nuttallii and Myriophyllum spicatum) with three levels of vegetative propagule pressure (4, 8 and 16 shoot fragments for communities in each pot) and two levels of water depth (30 cm and 70 cm). Increasing vegetative propagule pressure and decreasing water level significantly increased the growth of the submerged macrophyte communities, suggesting that propagule pressure and water depth should be considered when utilizing vegetative propagules to re-establish submerged macrophyte communities in degraded aquatic ecosystems. However, increasing vegetative propagule pressure and decreasing water level significantly decreased evenness of the submerged macrophyte communities because they markedly increased the dominance of H. verticillata and E. nuttallii, but had little impact on that of C. demersum and M. spicatum. Thus, effects of vegetative propagule pressure and water depth are species-specific and increasing vegetative propagule pressure under lower water level can facilitate the establishment success of submerged macrophyte communities.

Does mechanical disturbance affect the performance and species composition of submerged macrophyte communities?

Science.gov (United States)

Zhang, Qian; Xu, Ying-Shou; Huang, Lin; Xue, Wei; Sun, Gong-Qi; Zhang, Ming-Xiang; Yu, Fei-Hai

2014-05-01

Submerged macrophyte communities are frequently subjected to disturbance of various frequency and strength. However, there is still little experimental evidence on how mechanical disturbance affects the performance and species composition of such plant communities. In a greenhouse experiment, we constructed wetland communities consisting of five co-occurring clonal submerged macrophyte species (Hydrilla verticillata, Elodea canadensis, Ceratophyllum demersum, Chara fragilis, and Myriophyllum spicatum) and subjected these communities to three mechanical disturbance regimes (no, moderate and strong disturbance). Strong mechanical disturbance greatly decreased overall biomass, number of shoot nodes and total shoot length, and increased species diversity (evenness) of the total community. It also substantially decreased the growth of the most abundant species (H. verticillata), but did not affect growth of the other four species. Our data reveal that strong disturbance can have different effects on different submerged macrophyte species and thus alters the performance and species composition of submerged macrophyte communities.

Developing and testing a vertical sintering furnace for remote nuclear applications

International Nuclear Information System (INIS)

Nesbitt, J.F.; Ryer, C.M.

1980-01-01

Horizontal-type furnaces used to sinter fuel pellets on a production basis are large and thus impractical for remote applications. However, research has shown that vertical-type furnaces are adaptable for use and are cheaper to operate and maintain. In 1979, Pacific Northwest Laboratory, working under the auspices of the Department of Energy's Fuel Refabrication and Development (FRAD) Program, began developing an advanced concept for a remotely operated furnace designed specifically to sinter nuclear fuel pellets. The FRAD Program at PNL ended before the sintering of nuclear fuels could be completely verified. However during 1979, PNL performed a sufficient number and variety of tests to establish that nuclear fuel pellets can be sintered in a vertical furnace

Antioxidant activity of seedling growth in selected soybean genotypes (Glycine max (L.) Merrill) responses of submergence

Science.gov (United States)

Damanik, R. I.; Marbun, P.; Sihombing, L.

2016-08-01

In order to better understand the physiological and biochemical responses relating to direct seeding establishment in soybeans, the plant growth rate and antioxidative defense responses of seedlings in seven Indonesian soybean genotypes (Anjasmoro, Detam-1, Detam-2, Dieng, Grobogan, Tanggamus, and Willis) at different submergence periods (4, and 8 days) were examined. Twelve-day old seedlings were hydroponically grown in limited oxygen conditions. The results showed that the chlorophyll content in soybean seedlings was reduced beginning as early as 4 d under submerged condition, except for Detam-1, Detam-2, and Grobogan genotypes. The dry weight and protein concentration of seedlings were significantly higher at control condition (0 d) than those in submerged condition. The activities of superoxide dismutase (SOD) increased linearly until 8 d submerged for all genotypes. On the other hand, our results showed that catalase (CAT) and ascorbate peroxidase (APX) activities did not work together, meaning that CAT is activated and APX deactivated, or vice versa, in response to submergence conditions, except for Grobogan and Tanggamus genotypes which had an effect on both CAT and APX activities. Submergence stress led to a significant increase in glutathione reductase (GR) together with APX activity for Detam-2 and Dieng genotypes at 8 d submerged.

Integration of Tuyere, Raceway and Shaft Models for Predicting Blast Furnace Process

Science.gov (United States)

Fu, Dong; Tang, Guangwu; Zhao, Yongfu; D'Alessio, John; Zhou, Chenn Q.

2018-06-01

A novel modeling strategy is presented for simulating the blast furnace iron making process. Such physical and chemical phenomena are taking place across a wide range of length and time scales, and three models are developed to simulate different regions of the blast furnace, i.e., the tuyere model, the raceway model and the shaft model. This paper focuses on the integration of the three models to predict the entire blast furnace process. Mapping output and input between models and an iterative scheme are developed to establish communications between models. The effects of tuyere operation and burden distribution on blast furnace fuel efficiency are investigated numerically. The integration of different models provides a way to realistically simulate the blast furnace by improving the modeling resolution on local phenomena and minimizing the model assumptions.

Minimization of Blast furnace Fuel Rate by Optimizing Burden and Gas Distribution

Energy Technology Data Exchange (ETDEWEB)

Dr. Chenn Zhou

2012-08-15

The goal of the research is to improve the competitive edge of steel mills by using the advanced CFD technology to optimize the gas and burden distributions inside a blast furnace for achieving the best gas utilization. A state-of-the-art 3-D CFD model has been developed for simulating the gas distribution inside a blast furnace at given burden conditions, burden distribution and blast parameters. The comprehensive 3-D CFD model has been validated by plant measurement data from an actual blast furnace. Validation of the sub-models is also achieved. The user friendly software package named Blast Furnace Shaft Simulator (BFSS) has been developed to simulate the blast furnace shaft process. The research has significant benefits to the steel industry with high productivity, low energy consumption, and improved environment.

The effect of submergence on structural response in confined pools

International Nuclear Information System (INIS)

Sturm, A.J. Jr.; Song, C.C.S.

1980-01-01

In this paper the response of single and multi degree of submerged systems is investigated. The complete equations of motions including fluid coupling terms are developed for submerged bodies where the surrounding fluid is both moving in phase and out of phase with the support motion. The analysis considers both structural and fluid damping. Also included is an analysis of two degrees of freedom fluid coupling for submerged bodies completely enclosed within another body. In this case limiting conditions of the inner body hydrodynamic mass are examined, along the frequency response characteristics of these systems. The paper developes a simplified forcing function approach for in phase fluid support motion systems. This method is applicable for both modal-spectral and time history dynamic analyses of any linear structure. The results of the analysis are expanded for s structures with non-linear support configuration, i.e. (sliding or rocking bases) to again define a simplified analytical approach accounting for in phase fluid support motion. (orig.)

Process and furnace for working bituminous materials

Energy Technology Data Exchange (ETDEWEB)

Klotzer, M

1921-06-28

A process for working up bitumen-containing materials, such as coal, peat and shale is characterized in that the material in thin-height batches with constant shaking by means of forward and backward movement of an elongated horizontal hearth heated underneath on which the material freely lies and on which it is moved in the furnace, through a single narrow furnace space with zone-wise heating of the hearth. A drying zone, a spent-material removal zone, and a carbonization zone are provided. Under separate hoods the gases and vapors are removed from these zones.

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.

A review of NOx formation mechanisms in recovery furnaces

International Nuclear Information System (INIS)

Nichols, K.M.; Thompson, L.M.; Empie, H.J.

1993-01-01

Review of NOx formation studies shows that NO forms in recovery furnaces primarily by two independent mechanisms, thermal and fuel. Thermal NO formation is extremely temperature-sensitive. However, theoretical predictions indicate that recovery furnace temperatures are not high enough to form significant thermal NO. Fuel NO formation is less temperature-sensitive, and is related to fuel nitrogen content. Black liquors are shown to contain 0.05 to 0.24 weight percent fuel nitrogen. Conversion of just 20% of this would yield approximately 25-120 ppm NOx (at 8% 0 2 ) in the flue gas, enough to represent the majority of the total NOx. Data from operating recovery furnaces show NOx emissions ranging from near zero to over 100 ppm at 8% 0 2 . An apparent increase in recovery furnace NOx emissions was observed with increasing solids. This increase is much less than predicted by thermal NO formation theory, indicating that other NO formation/destruction mechanisms, such as fuel NO formation, are important. No data are available to show the relative importance of thermal and fuel NO to total NOx during black liquor combustion

Modified Application of Nitrogen Fertilizer for Increasing Rice Variety Tolerance toward Submergence Stress

Directory of Open Access Journals (Sweden)

Gribaldi Gribaldi

2017-01-01

Full Text Available This research was conducted from July to October 2015, using Randomized Block Design with two treatment factors and three replications for each treatment. The first factor was rice varieties (V: V1 = IR 64; V2 = Inpara 5. The second factor was fertilizer (N: N0: without submergence, all N fertilizer was given during planting; N1: all N fertilizer dose was given during planting; and N2: 1/2 dose of N fertilizer was given during planting; the rest was given at 42 days after planting. The submergence was during 7–14 days after planting; N3 = the entire dose of N fertilizer that was given during planting, N4 = 1/2 the dose of N fertilizer that was given during planting, and the rest was given at 42 days after planting. The submergence was during 7–14 and 28–35 days after planting. The results showed that the management of nitrogen fertilizer application had effect on rice growth and production which experienced dirty water submergence stress; the application of 1/2 dose of N fertilizer given during planting had the best effect on rice growth and production; the longer the submergence period for rice variety, the higher the effect on rice growth and production.

Suspension of Egg Hatching Caused by High Humidity and Submergence in Spider Mites.

Science.gov (United States)

Ubara, Masashi; Osakabe, Masahiro

2015-08-01

We tested the effects of high humidity and submergence on egg hatching of spider mites. In both the high humidity and submergence treatments, many Tetranychus and Panonychus eggs did not hatch until after the hatching peak of the lower humidity or unsubmerged controls. However, after humidity decreased or water was drained, many eggs hatched within 1-3 h. This was observed regardless of when high humidity or submergence treatments were implemented: either immediately after oviposition or immediately before hatching was due. Normal eyespot formation was observed in most eggs in the high humidity and submergence treatments, which indicates that spider mite embryos develop even when eggs are underwater. Therefore, delays in hatching are not caused by delayed embryonic development. A delay in hatching was always observed in Panonychus citri (McGregor) but was more variable in Tetranychus urticae Koch and Tetranychus kanzawai Kishida. The high humidity and submergence treatments affected but did not suppress larval development in these species. In contrast, many Oligonychus eggs died following the high humidity treatments. In Tetranychus and Panonychus spider mites, suspension of egg hatching may mitigate the adverse effects of rainfall. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of a burning mass ceramics coating in laboratory furnace and instrustrial furnace; Comparacao de queimas de uma massa ceramica de revestimento em forno de laboratorio e forno industrial

Energy Technology Data Exchange (ETDEWEB)

Soares, R.A.L., E-mail: robertoarruda@ifpi.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Piaui (IFPI), Terersina, PI (Brazil); Castro, J.R. de S. [Universidade Federal do Piaui (UFPI), Teresina, PI (Brazil)

2012-07-01

This work intends to analyze the differences obtained in the technological properties of a ceramic coating after firing in two distinct environments, laboratory furnace and industrial furnace. For this, was characterized a ceramic mass used in the production of porous coating. The analyzes were performed chemical, mineralogical and thermal mass in that. The specimens were obtained by compacting and burned in the maximum temperature of 1140 deg C in two furnaces, laboratory and industrial. The technological tests were performed linear shrinkage, water absorption, bulk density and mechanical strength. The microstructure was evaluated by ray-X diffraction and scanning electron microscopy. The results showed that both furnaces provided significant differences in analyzed specimens, such as increased strength and low water absorption in the fired samples in a laboratory furnace, for example. (author)

Numerical modelling of an industrial glass-melting furnace

Energy Technology Data Exchange (ETDEWEB)

Hill, S C [Brigham Young Univ., Advanced Combustion Engineering Research Center, Provo, UT (United States); Webb, B W; McQuay, M Q [Brigham Young Univ., Mechanical Engineering Dept., Provo, UT (United States); Newbold, J [Lockheed Aerospace, Denver, CO (United States)

2000-03-01

The predictive capability of two comprehensive combustion codes, PCGC-3 and FLUENT, to simulate local flame structure and combustion characteristics in a industrial gas-fired, flat-glass furnace is investigated. Model predictions are compared with experimental data from the furnace for profiles of velocity, species concentrations, temperatures, and wall-incident radiative heat flux. Predictions from both codes show agreement with the measured mean velocity profiles and incident radiant flux on the crown. However, significant differences between the code predictions and measurements are observed for the flame-ozone temperatures and species concentrations. The observed discrepancies may be explained by (i) uncertainties in the distributions of mean velocity and turbulence in the portneck, (ii) uncertainties in the port-by-port stoichiometry, (iii) different grid-based approximations to the furnace geometry made in the two codes, (iv) the assumption of infinitely fast chemistry made in the chemical reaction model of both codes, and (v) simplifying assumptions made in the simulations regarding the complex coupling between the combustion space, batch blanket, and melt tank. The study illustrates the critical need for accurate boundary conditions (inlet air and fuel flow distributions, boundary surface temperatures, etc.) and the importance of representative furnace geometry in simulating these complex industrial combustion systems. (Author)

Steam generators and furnaces

Energy Technology Data Exchange (ETDEWEB)

Swoboda, E

1978-04-01

The documents published in 1977 in the field of steam generators for conventional thermal power plants are classified according to the following subjects: power industry and number of power plants, planning and operation, design and construction, furnaces, environmental effects, dirt accumulation and corrosion, conservation and scouring, control and automation, fundamental research, and materials.

DEVELOPMENT AND TESTING OF COMPOUND FUEL CHAMBER WITHOUT A GRATE FOR HOUSEHOLD FURNACE

Directory of Open Access Journals (Sweden)

Shevyakov Vladimir Viktorovich

2018-02-01

Full Text Available In hearth furnaces, the firewood is burned more cleanly with less carbon monoxide at the outlet. The disadvantage of such fireboxes is a longer process of coal burnout than in grate-fired furnaces. In furnaces with a grate, the burnout time of coals is less, which makes it possible to finish the combustion process more quickly and close the outlet latch. This increases the efficiency of the furnace but to further reduce the time of burning out the coals they have to be raked and burned on the grate. This complicates the process of operating the furnace itself. The proposed design of the compound firebox allows us to improve characteristics of both the firebox itself and the entire furnace. Research objectives: creation and study of a compound firebox that increases the efficiency of the furnace and simplifies the furnace maintenance process with the values of carbon monoxide at the outlet comparable to hearth furnaces. Materials and methods: a detailed analysis of hearth fuel chambers ECO+ was carried out according to the amount of carbon monoxide at the outlet. The results of the analysis are used for comparison with compound fuel chamber. The structure of the compound firebox was chosen based on the results of preliminary tests of several fuel chambers proposed and tested by the author in the furnace PDKSh-2.0. A peculiarity of the structure of the compound firebox is the absence of a grate and the presence of a narrow slit in the lower part of the firebox through which the incoming air enters the firewood. Between the walls of the firebox and firewood, skids are installed, forming an air gap, through which the inlet air is uniformly supplied to the entire firewood supply. With gradual combustion of firewood and formation of coal, the firewood descends to the bottom of the firebox, where they intensively burn out in the maximum air flow. Compound firebox consists of several parts, it is made of steel with a thickness of 4.0 mm and installed

THE REDSHIFT DISTRIBUTION OF GIANT ARCS IN THE SLOAN GIANT ARCS SURVEY

International Nuclear Information System (INIS)

Bayliss, Matthew B.; Gladders, Michael D.; Koester, Benjamin P.; Oguri, Masamune; Hennawi, Joseph F.; Sharon, Keren; Dahle, Haakon

2011-01-01

We measure the redshift distribution of a sample of 28 giant arcs discovered as a part of the Sloan Giant Arcs Survey. Gemini/GMOS-North spectroscopy provides precise redshifts for 24 arcs, and 'redshift desert' constrains for the remaining 4 arcs. This is a direct measurement of the redshift distribution of a uniformly selected sample of bright giant arcs, which is an observable that can be used to inform efforts to predict giant arc statistics. Our primary giant arc sample has a median redshift z = 1.821 and nearly two-thirds of the arcs, 64%, are sources at z ∼> 1.4, indicating that the population of background sources that are strongly lensed into bright giant arcs resides primarily at high redshift. We also analyze the distribution of redshifts for 19 secondary strongly lensed background sources that are not visually apparent in Sloan Digital Sky Survey imaging, but were identified in deeper follow-up imaging of the lensing cluster fields. Our redshift sample for the secondary sources is not spectroscopically complete, but combining it with our primary giant arc sample suggests that a large fraction of all background galaxies that are strongly lensed by foreground clusters reside at z ∼> 1.4. Kolmogorov-Smirnov tests indicate that our well-selected, spectroscopically complete primary giant arc redshift sample can be reproduced with a model distribution that is constructed from a combination of results from studies of strong-lensing clusters in numerical simulations and observational constraints on the galaxy luminosity function.

Invasive crayfish threaten the development of submerged macrophytes in lake restoration.

Science.gov (United States)

van der Wal, Jessica E M; Dorenbosch, Martijn; Immers, Anne K; Vidal Forteza, Constanza; Geurts, Jeroen J M; Peeters, Edwin T H M; Koese, Bram; Bakker, Elisabeth S

2013-01-01

Submerged macrophytes enhance water transparency and aquatic biodiversity in shallow water ecosystems. Therefore, the return of submerged macrophytes is the target of many lake restoration projects. However, at present, north-western European aquatic ecosystems are increasingly invaded by omnivorous exotic crayfish. We hypothesize that invasive crayfish pose a novel constraint on the regeneration of submerged macrophytes in restored lakes and may jeopardize restoration efforts. We experimentally investigated whether the invasive crayfish (Procambarus clarkii Girard) affects submerged macrophyte development in a Dutch peat lake where these crayfish are expanding rapidly. Seemingly favourable abiotic conditions for macrophyte growth existed in two 0.5 ha lake enclosures, which provided shelter and reduced turbidity, and in one lake enclosure iron was added to reduce internal nutrient loading, but macrophytes did not emerge. We transplanted three submerged macrophyte species in a full factorial exclosure experiment, where we separated the effect of crayfish from large vertebrates using different mesh sizes combined with a caging treatment stocked with crayfish only. The three transplanted macrophytes grew rapidly when protected from grazing in both lake enclosures, demonstrating that abiotic conditions for growth were suitable. Crayfish strongly reduced biomass and survival of all three macrophyte species while waterfowl and fish had no additive effects. Gut contents showed that crayfish were mostly carnivorous, but also consumed macrophytes. We show that P. clarkii strongly inhibit macrophyte development once favourable abiotic conditions for macrophyte growth are restored. Therefore, expansion of invasive crayfish poses a novel threat to the restoration of shallow water bodies in north-western Europe. Prevention of introduction and spread of crayfish is urgent, as management of invasive crayfish populations is very difficult.

Design and Construction of Oil Fired Compact Crucible Furnace ...

African Journals Online (AJOL)

As a prelude to necessary industrialization, foundries are springing up in various parts of Nigeria and most of these foundries rely on oil fired furnaces in their operation. This study is aimed at developing an oil fired crucible furnace from locally sourced materials for foundries in Nigeria. In our design, a new system of fuel ...

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 kg...

Effects of stern-foil submerged elevation on the lift and drag of a hydrofoil craft

Science.gov (United States)

Suastika, K.; Apriansyah

2018-03-01

Effects of the stern-foil submerged elevation on the lift and drag of a hydrofoil craft are studied by using computational fluid dynamics (CFD) and by considering three alternative stern-foil submerged elevations. The submerged elevation of the front foil is kept constant in all the alternatives. From among the alternatives, the deepest stern-foil placement results in the highest stern-foil lift with the highest foil’s lift-to-drag ratio. However, considering the lift-to-drag ratio of the whole foil-strut-hull system, the shallowest stern-foil placement results in the highest lift-to-drag ratio. The struts and the foil’s submerged elevation significantly affects the drag of the whole foil-strut-hull system.

Measurement of Submerged Oil/Gas Leaks using ROV Video

Science.gov (United States)

Shaffer, Franklin; de Vera, Giorgio; Lee, Kenneth; Savas, Ömer

2013-11-01

Drilling for oil or gas in the Gulf of Mexico is increasing rapidly at depths up to three miles. The National Commission on the Deepwater Horizon Oil Leak concluded that inaccurate estimates of the leak rate from the Deepwater Horizon caused an inadequate response and attempts to cap the leak to fail. The first response to a submerged oil/gas leak will be to send a Remotely Operated Vehicle (ROV) down to view the leak. During the response to the Deepwater Horizon crisis, the authors Savas and Shaffer were members of the Flow Rate Technical Group's Plume Team who used ROV video to develop the FRTG's first official estimates of the oil leak rate. Savas and Shaffer developed an approach using the larger, faster jet features (e.g., turbulent eddies, vortices, entrained particles) in the near-field developing zone to measure discharge rates. The authors have since used the Berkeley Tow Tank to test this approach on submerged dye-colored water jets and compressed air jets. Image Correlation Velocimetry has been applied to measure the velocity of visible features. Results from tests in the Berkeley Tow Tank and submerged oil jets in the OHMSETT facility will be presented.

Detecting submerged features in water: modeling, sensors, and measurements

Science.gov (United States)

Bostater, Charles R., Jr.; Bassetti, Luce

2004-11-01

It is becoming more important to understand the remote sensing systems and associated autonomous or semi-autonomous methodologies (robotic & mechatronics) that may be utilized in freshwater and marine aquatic environments. This need comes from several issues related not only to advances in our scientific understanding and technological capabilities, but also from the desire to insure that the risk associated with UXO (unexploded ordnance), related submerged mines, as well as submerged targets (such as submerged aquatic vegetation) and debris left from previous human activities are remotely sensed and identified followed by reduced risks through detection and removal. This paper will describe (a) remote sensing systems, (b) platforms (fixed and mobile, as well as to demonstrate (c) the value of thinking in terms of scalability as well as modularity in the design and application of new systems now being constructed within our laboratory and other laboratories, as well as future systems. New remote sensing systems - moving or fixed sensing systems, as well as autonomous or semi-autonomous robotic and mechatronic systems will be essential to secure domestic preparedness for humanitarian reasons. These remote sensing systems hold tremendous value, if thoughtfully designed for other applications which include environmental monitoring in ambient environments.

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.

Influence of the composition and microstructure on the mechanical properties of single pass weld metal obtained with two-run multipower submerged arc welding of 35 MM Fe 510 quality steels

International Nuclear Information System (INIS)

Berkhout, C.F.; Sipkes, M.P.

1977-01-01

For three 35 mm Fe 510 quality steels (with and without niobium) experiments have been carried out to establish a relationship between composition, microstructure and mechanical properties of weldmetal obtained with two-run multipower submerged arc welding. The most striking aspects are summarized in the following. The weldmental composition can influence the toughness both, directly by matrix alloying or indirectly through the grainsize and constituents of the microstructure such as the perlite-cementite and martensite fraction. In the range of compositions investigated Mn for instance has a beneficial, while Nb and N have a detrimental effect on notch toughness. For nitrogen the concentration in the weldmetal is determined by the type of weldingflux used. The unfavourable effect of Nb in the weldmetal depends mainly on the Nb content of the plate material (dilution effect). Niobium introduced by the flux is not active and in all probability only present as non metallic inclusions. Remarkable is the strong interaction found between Nb and N. The influence of Nb decreases when the N content of the weldmetal increases. This effect may probably also be an explanation for the great differences in the interpretation of the influence of Nb on weldmetal ductility as mentioned in the literature. A change in the concentration of these elements does not have any influence on the grainsize of the weldmetal. The influence of Mo is quite remarkable. In the first place it has a grain-refining effect, which strongly predominates its detrimental effect in promoting the martensite formation. From quantitative measurements it also appears that Mo reduces the amount of perlite in the weldmetal and suppresses entirely the influence of Mn on the Charpy-V transition temperature and the uppershelf-energy level

The technological raw material heating furnaces operation efficiency improving issue

Science.gov (United States)

Paramonov, A. M.

2017-08-01

The issue of fuel oil applying efficiency improving in the technological raw material heating furnaces by means of its combustion intensification is considered in the paper. The technical and economic optimization problem of the fuel oil heating before combustion is solved. The fuel oil heating optimal temperature defining method and algorithm analytically considering the correlation of thermal, operating parameters and discounted costs for the heating furnace were developed. The obtained optimization functionality provides the heating furnace appropriate thermal indices achievement at minimum discounted costs. The carried out research results prove the expediency of the proposed solutions using.

Plan quality comparison between 4-arc and 6-arc noncoplanar volumetric modulated arc stereotactic radiotherapy for the treatment of multiple brain metastases.

Science.gov (United States)

Yoshio, Kotaro; Mitsuhashi, Toshiharu; Wakita, Akihisa; Kitayama, Takahiro; Hisazumi, Kento; Inoue, Daisaku; Shiode, Tsuyoki; Akaki, Shiro; Kanazawa, Susumu

2018-01-04

To compare the plans of 4-arc and 6-arc noncoplanar volumetric modulated arc stereotactic radiotherapy (VMA-SRT) for multiple brain metastases and to investigate the cutoff value for the tumor number and volume for 6-arc rather than 4-arc VMA-SRT. We identified 24 consecutive multiple-target cases (3 to 19 targets in each case) with 189 total targets. We constructed plans using both 4- and 6-arc noncoplanar VMA-SRT. The prescribed dose was 36 Gy/6 fr, and it was delivered to 95% of the planning target volume (PTV). The plans were evaluated for the dose conformity using the Radiation Therapy Oncology Group and Paddick conformity indices (RCI and PCI), fall-off (Paddick gradient index [PGI]), and the normal brain dose. The median (range) RCI, PCI, and PGI was 0.94 (0.92 to 0.99), 0.89 (0.77 to 0.94), and 3.75 (2.24 to 6.54) for the 4-arc plan and 0.94 (0.91 to 0.98), 0.89 (0.76 to 0.94), and 3.65 (2.24 to 6.5) for the 6-arc plan, respectively. The median (range) of the normal brain dose was 910.3 cGy (381.4 to 1268.9) for the 4-arc plan and 898.8 cGy (377 to 1252.9) for the 6-arc plan. The PGI of the 6-arc plan was significantly superior to that of the 4-arc plan (p = 0.0076), and the optimal cutoff values for the tumor number and volume indicative of 6-arc (and not 4-arc) VMA-SRT were cases with ≥ 5 metastases and a PTV of ≥ 12.9 mL, respectively. The PCI values, however, showed no significant difference between the 2 plans. We believe these results will help in considering the use of 6-arc VMA-SRT for multiple brain metastases. Copyright © 2017 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

Submerged macrophytes modify bacterial community composition in sediments in a large, shallow, freshwater lake.

Science.gov (United States)

Zhao, Da-Yong; Liu, Peng; Fang, Chao; Sun, Yi-Meng; Zeng, Jin; Wang, Jian-Qun; Ma, Ting; Xiao, Yi-Hong; Wu, Qinglong L

2013-04-01

Submerged aquatic macrophytes are an important part of the lacustrine ecosystem. In this study, the bacterial community compositions in the rhizosphere sediments from three kinds of submerged macrophytes (Ceratophyllum demersum, Potamogeton crispus, and Vallisneria natans) were investigated to determine whether submerged macrophytes could drive the variation of bacterial community in the eutrophic Taihu Lake, China. Molecular techniques, including terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified 16S rRNA gene and clone libraries, were employed to analyze the bacterial community compositions. Remarkable differences of the T-RFLP patterns were observed among the different samples, and the results of LIBSHUFF analysis also confirmed that the bacterial community compositions in the rhizosphere sediments of three kinds of submerged macrophytes were statistically different from that of the unvegetated sediment. Acidobacteria, Deltaproteobacteria, and Betaproteobacteria were the dominant bacterial groups in the rhizosphere sediments of Ceratophyllum demersum, Potamogeton crispus, and Vallisneria natans, respectively, accounting for 15.38%, 29.03%, and 18.00% of the total bacterial abundances. Our study demonstrated that submerged macrophytes could influence the bacterial community compositions in their rhizosphere sediments, suggesting that macrophytes have an effect on the cycling and transportation of nutrients in the freshwater lake ecosystem.

Vegetative Propagule Pressure and Water Depth Affect Biomass and Evenness of Submerged Macrophyte Communities.

Directory of Open Access Journals (Sweden)

Hong-Li Li

Full Text Available Vegetative propagule pressure may affect the establishment and structure of aquatic plant communities that are commonly dominated by plants capable of clonal growth. We experimentally constructed aquatic communities consisting of four submerged macrophytes (Hydrilla verticillata, Ceratophyllum demersum, Elodea nuttallii and Myriophyllum spicatum with three levels of vegetative propagule pressure (4, 8 and 16 shoot fragments for communities in each pot and two levels of water depth (30 cm and 70 cm. Increasing vegetative propagule pressure and decreasing water level significantly increased the growth of the submerged macrophyte communities, suggesting that propagule pressure and water depth should be considered when utilizing vegetative propagules to re-establish submerged macrophyte communities in degraded aquatic ecosystems. However, increasing vegetative propagule pressure and decreasing water level significantly decreased evenness of the submerged macrophyte communities because they markedly increased the dominance of H. verticillata and E. nuttallii, but had little impact on that of C. demersum and M. spicatum. Thus, effects of vegetative propagule pressure and water depth are species-specific and increasing vegetative propagule pressure under lower water level can facilitate the establishment success of submerged macrophyte communities.

Experimental Study on Environment Friendly Tap Hole Clay for Blast Furnace

Science.gov (United States)

Siva kumar, R.; Mohammed, Raffi; Srinivasa Rao, K.

2018-03-01

Blast furnace (BF) is the best possible route of iron production available. Blast furnace is a high pressure vessel where iron ore is melted and liquid iron is produced. The liquid iron is tapped through the hole in Blast Furnace called tap hole. The tapped liquid metal flowing through the tap hole is plugged using a clay called tap hole clay. Tap hole clay (THC) is a unshaped refractory used to plug the tap hole. The tap hole clay extruded through the tap hole using a gun. The tap hole clay is designed to expand and plug the tap hole. The tap hole filled with clay is drilled using drill bit and the hole made through the tap hole to tap the liquid metal accumulated inside the furnace. The number of plugging and drilling varies depending on the volume of the furnace. The tap hole clay need to have certain properties to avoid problems during plugging and drilling. In the present paper tap hole clay properties in industrial use was tested and studied. The problems were identified related to tap hole clay manufacturing. Experiments were conducted in lab scale to solve the identified problems. The present composition was modified with experimental results. The properties of the modified tap hole clay were found suitable and useful for blast furnace operation with lab scale experimental results.

Design of safety monitor system for operation sintering furnace ME-06

International Nuclear Information System (INIS)

Sugeng Rianto; Triarjo; Djoko Kisworo; Agus Sartono

2013-01-01

Design of safety monitoring system for safety operation of sinter furnace ME-06 has been done. Parameters monitored during this operation include: temperature, gas pressure, flow rate of gas, voltage and current furnace. For sintering furnace temperature system that monitored were the temperature of the furnace temperature, the temperature of the cooling water system inlet and outlet, temperature of flow hydrogen gas inlet and outlet. For pressure system and flow rate gas sinter furnace which monitored the pressure and flow rate of hydrogen gas inlet and outlet. The system also monitors current and voltage applied to the sinter furnace heating system. Monitor system hardware consists of: the system temperature sensor, pressure, rate and data acquisition systems. While software systems using the labview driver interface that connects the hard and software systems. Function test results during sintering operation for setting the temperature 1700 °C sintering temperature increases the ramp function by 250 °C/hour average measurements obtained when the sintering time 1707.016 °C with a standard deviation of 0.38 °C. The maximum temperature of the hydrogen gas temperature 35.4 °C. The maximum temperature of the cooling water system 27.4 °C. The maximum pressure of 1,911 bar Gas Inlet and outlet of 0,051 bar. Maximum inlet gas flow 12.996 L / min and outlet 14.086 L / min. (author)

Mathematical Determination of Thermal Load for Fluidised Bed Furnaces Using Sawdust

Directory of Open Access Journals (Sweden)

Antonescu Nicolae

2014-06-01

Full Text Available For technical applications, a physical model capable of predicting the particle evolution in the burning process along its trajectory through the furnace is very useful. There are two major demands: all the thermo-dynamic processes that describe the particle burning process must be accounted and the model must be written in such equation terms to allow the intervention for parameter settings and particle definition. The computations were performed for the following parameters: furnace average temperature between 700 and 1200 °C, size of the sawdust particle from 4 to 6 mm and fix carbon ignition between 500 and 900 °C. The values obtained for the characteristic parameters of the burning process ranged from 30 to 60 [kg/(h·m3] for the gravimetrical burning speed WGh and from 150 to 280 [kW/m3] for the volumetric thermal load of the furnace QV. The main conclusion was that the calculus results are in good agreement with the experimental data from the pilot installations and the real-case measurements in the sawdust working boiler furnaces or pre-burning chambers. Another very important conclusion is that the process speed variation, when the furnace temperature changes, confirms the thermo-kinetic predictions, namely that the burning process speed decreases when the furnace temperature increases.

Arc dynamics of a pulsed DC nitrogen rotating gliding arc discharge

Science.gov (United States)

Zhu, Fengsen; Zhang, Hao; Li, Xiaodong; Wu, Angjian; Yan, Jianhua; Ni, Mingjiang; Tu, Xin

2018-03-01

In this study, a novel pulsed direct current (DC) rotating gliding arc (RGA) plasma reactor co-driven by an external magnetic field and a tangential gas flow has been developed. The dynamic characteristics of the rotating gliding arc have been investigated by means of numerical simulation and experiment. The simulation results show that a highly turbulent vortex flow can be generated at the bottom of the RGA reactor to accelerate the arc rotation after arc ignition, whereas the magnitude of gas velocity declined significantly along the axial direction of the RGA reactor. The calculated arc rotation frequency (14.4 Hz) is reasonably close to the experimental result (18.5 Hz) at a gas flow rate of 10 l min-1. In the presence of an external magnet, the arc rotation frequency is around five times higher than that of the RGA reactor without using a magnet, which suggests that the external magnetic field plays a dominant role in the maintenance of the arc rotation in the upper zone of the RGA reactor. In addition, when the magnet is placed outside the reactor reversely to form a reverse external magnetic field, the arc can be stabilized at a fixed position in the inner wall of the outer electrode at a critical gas flow rate of 16 l min-1.

CO2 Mineralization and Utilization using Steel Slag for Establishing a Waste-to-Resource Supply Chain.

Science.gov (United States)

Pan, Shu-Yuan; Chung, Tai-Chun; Ho, Chang-Ching; Hou, Chin-Jen; Chen, Yi-Hung; Chiang, Pen-Chi

2017-12-08

Both steelmaking via an electric arc furnace and manufacturing of portland cement are energy-intensive and resource-exploiting processes, with great amounts of carbon dioxide (CO 2 ) emission and alkaline solid waste generation. In fact, most CO 2 capture and storage technologies are currently too expensive to be widely applied in industries. Moreover, proper stabilization prior to utilization of electric arc furnace slag are still challenging due to its high alkalinity, heavy metal leaching potentials and volume instability. Here we deploy an integrated approach to mineralizing flue gas CO 2 using electric arc furnace slag while utilizing the reacted product as supplementary cementitious materials to establish a waste-to-resource supply chain toward a circular economy. We found that the flue gas CO 2 was rapidly mineralized into calcite precipitates using electric arc furnace slag. The carbonated slag can be successfully utilized as green construction materials in blended cement mortar. By this modulus, the global CO 2 reduction potential using iron and steel slags was estimated to be ~138 million tons per year.

Liquid flow in the hearth of the blast furnace

International Nuclear Information System (INIS)

Gauje, P.; Nicolle, R.; Steiler, J.M.; Venturini, M.J.; Libralesso, J.M.

1992-01-01

The hearth of a blast furnace is poorly known. Our approach to characterize the hearth involves classical methods of chemical engineering, assessing the flow conditions by means of radioactive tracer techniques. The most important feature of this study is to combine measurements on industrial blast furnaces, experiments on a small scale model and flow model. calculations. 8 refs., 16 figs

Effect of addition of arc furnace dust in the microstructural properties of fly ash alkali-activated; Estudo do efeito da adicao do po de aciaria nas propriedades microestruturais de matrizes a base de cinzas volantes alcali-ativadas

Energy Technology Data Exchange (ETDEWEB)

Vargas, Alexandre Silva de [Centro de Estudos Superiores Feevale, Novo Hamburgo, RS (Brazil); Pavao, Bruno Barreto; Masuero, Angela Boreges; Dal Molin, Denise Carpena Coitinho; Vilela, Antonio Cezar Faria [Universidade Federal do Rio Grande do Sul (UFRS), RS (Brazil)

2010-07-01

The search for alternative materials for construction, with less environmental impact, has been the subject of several studies. The alkali-activated cements have shown potential for the reuse of waste, and can be used in the technology of solidification/stabilization. Thus, this study aims to evaluate the main effect of adding arc furnace dust (AFD) in the microstructural properties of matrices based on fly ash alkali-activated. Three levels of AFD were studied: 0, 5, 15 and 25%. The curing was set at 70°C/24 h, and after, kept at room temperature until the age of analysis - 1, 28 and 180 days, with XRD and FTIR analysis. In the XRD spectres it was found that compounds of albite and natron decrease the intensity of their peaks in that there is an increase in the levels of AFD. Concerning to the FTIR, we observed that the band characteristic of the fly ash (FA) 1084 cm{sup -1} was shifted to bands near 1000 cm{sup -1}, which shows that the residue does not interfere in the polymerization and aluminosilicate gel formation. Therefore, under the microstructural aspect, there were no major changes that would impair the use of this residue in alkali-activated matrices. (author)

Granulated blast furnace slag – A boon for foundry industry

African Journals Online (AJOL)

Keywords: Silica sand; Blast Furnace Slag; Mould properties; Ferrous and nonferrous ... raw material for the production of cast components in foundry industries. ... applications for conserving natural resources and reduce the cost of the raw .... in an elevated temperature melting furnace with temperature values of 750 to.

Modeling of glass fusion furnaces; Modelisation des fours de fusion de verre

Energy Technology Data Exchange (ETDEWEB)

Mechitoua, N. [Electricite de France (EDF), 78 - Chatou (France). Direction des Etudes et Recherches; Plard, C. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

1997-12-31

The furnaces used for glass melting are industrial installations inside which complex and coupled physical and chemical phenomena occur. Thermal engineering plays a major role and numerical simulation is a precious tool for the analysis of the different coupling, of their interaction and of the influence of the different parameters. In order to optimize the functioning of glass furnaces and to improve the quality of the glass produced, Electricite de France (EdF) has developed a specialized version of the ESTET fluid mechanics code, called `Joule`. This paper describes the functioning principle of glass furnaces, the interactions between heat transfers and flows inside the melted glass, the interactions between heat transfers and the thermal regulation of the furnace, the interactions between heat transfers and glass quality and the heat transfer interactions between the melted glass, the furnace walls and the combustion area. (J.S.)

X-ray diffractometry of steam cured ordinary Portland and blast-furnace-slag cements

International Nuclear Information System (INIS)

Camarini, G.; Djanikian, J.G.

1994-01-01

This work studies some aspects of the phases produced by hydration of ordinary and blast-furnace-slag cements, at normal conditions and steam cured (60 and 95 0 C), using an X-ray diffraction technique. The blast-furnace-slag cement was a mixture of 50% of ordinary Portland cement and 50% of blast-furnace-slag (separately grinding). After curing the X-ray diffraction reveals that, in relation to ordinary Portland cement, the main phases in blast-furnace-slag cement are hydrated silicates and aluminates, hydro garnet, etringitte and mono sulphate. After steam curing the hydration of blast-furnace-slag cement proceeds. This is a result of the slag activation by the curing temperature. (author). 8 refs., 3 figs., 1 tab

arcControlTower: the System for Atlas Production and Analysis on ARC

International Nuclear Information System (INIS)

Filipcic, Andrej

2011-01-01

PanDA, the Atlas management and distribution system for production and analysis jobs on EGEE and OSG clusters, is based on pilot jobs to increase the throughput and stability of the job execution on grid. The ARC middleware uses a specific approach which tightly connects the job requirements with cluster capabilities like resource usage, software availability and caching of input files. The pilot concept renders the ARC features useless. The arcControlTower is the job submission system which merges the pilot benefits and ARC advantages. It takes the pilot payload from the panda server and submits the jobs to the Nordugrid ARC clusters as regular jobs, with all the job resources known in advance. All the pilot communication with the PanDA server is done by the arcControlTower, so it plays the role of a pilot factory and the pilot itself. There are several advantages to this approach: no grid middleware is needed on the worker nodes, the fair-share between the production and user jobs is tuned with the arcControlTower load parameters, the jobs can be controlled by ARC client tools. The system could be extended to other submission systems using central distribution.

Factors affecting palatability of four submerged macrophytes for grass carp Ctenopharyngodon idella.

Science.gov (United States)

Sun, Jian; Wang, Long; Ma, Lin; Min, Fenli; Huang, Tao; Zhang, Yi; Wu, Zhenbin; He, Feng

2017-12-01

Grass carp can weaken the growth and reproductive capacity of submerged macrophytes by consuming valuable tissues, but factors affecting palatability of submerged macrophytes for grass carp rarely are considered. In this study, relative consumption rate of grass carp with regard to submerged macrophytes was in the following order: Hydrilla verticillata > Vallisneria natans > Ceratophyllum demersum > Myriophyllum spicatum. Firmness of macrophytes was in the following order: M. spicatum > C. demersum > H. verticillata = V. natans, whereas shear force was M. spicatum > C. demersum > H. verticillata > V. natans. After crude extracts of M. spicatum were combined with H. verticillata, grass carp fed on fewer macrophyte pellets that contained more plant secondary metabolites (PSMs). This indicated that structure and PSMs affected palatability of macrophytes.PSMs do not contribute to reduction in palatability through inhibition of intestinal proteinases activity, but they can cause a decrease in the abundance of Exiguobacterium, Acinetobacter-yielding proteases, lipases, and cellulose activity, which in turn can weaken the metabolic capacity of grass carp and adversely affect their growth. Thus, the disadvantages to the growth and development of grass carp caused by PSMs may drive grass carp to feed on palatable submerged macrophytes with lower PSMs.