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Sample records for susceptibility porosity furnace

  1. Comparative study of porosity and pores morphology of unalloyed iron sintered in furnace and plasma reactor

    Directory of Open Access Journals (Sweden)

    Henrique Cezar Pavanati

    2007-03-01

    Full Text Available Samples of unalloyed iron were sintered in the presence of an abnormal glow discharge using a confined anode-cathode configuration. The samples were placed on a holder acting as the discharge anode inside an AISI 1020 steel hollow cathode. Heating of the outer cathode was obtained by the bombardment of ions and energetic neutral particles. As a consequence of the confined geometry, the sample was efficiently heated mainly by radiation from the cathode. In order to evaluate the results of the sintering process by plasma, samples of unalloyed iron were also sintered in a resistive furnace using the same thermal cycle. The porosity, dimension and morphology of the pores were characterized by means of four basic parameters: area fraction, mean diameter, shape factor and elongation factor. The results show that the shape factor depends on the pore size, a characteristic that was not observed for elongation factor. For samples sintered in plasma reactor or conventional furnace, no significant difference in the porosity or in the pores morphology was observed.

  2. EFFECT OF CURING TEMPERATURE IN THE ALKALI-ACTIVATED BLAST-FURNACE SLAG PASTE AND THEIR STRUCTURAL INFLUENCE OF POROSITY

    Directory of Open Access Journals (Sweden)

    Teresita de Jesús Medina-Serna

    2016-09-01

    Full Text Available Due to the environmental problem posed by the use of Portland cement as construction material, it becomes necessary the search for supplementary cementitious materials that mitigate the ecological damage caused by it. Because the chemical similarity and the high cementitious powers of the blast furnace slag, it is used in the generation of geopolymers in a cement total replacement. This research focused on the study of the influence of the curing conditions on the final properties of blast furnace slag establishing three variables: no cured process (N-C, cured of controlled temperature of 45°C (CT45-C and room temperature cure (RT-C; evaluating the mechanical behavior until 28 days of age and the water porosity index. The results show that geopolymers based on blast furnace slag has a behavior similar to hydration maturity of Portland cement and curing process decreases the porosity; On the other hand, applying a controlled temperature generates densest resistant pastes such as the variable CT45-C which reach the highest value of resistance in all curing ages.

  3. Effect of SCM on porosity

    DEFF Research Database (Denmark)

    Canut, Mariana

    and connectivity of pores affect durability. Supplementary cementitious materials (SCMs) are being increasingly used as a substitute for Portland cement in the interests of sustainability and to improve the engineering properties of concrete as strength and durability. SCMs are by-products such as slag from iron...... blast furnaces, fly ash from coal fired power stations, and silica fume from ferrosilicon production. Studies suggest that the improvement of the strength and durability using SCMs are governed by refinement of the pores in the cement paste. Both the chemical and physical properties of the SCMs......Pores are an inherent part of cement-based materials. The pores range from nm to cm varying in shape and distribution. The amount, size and distribution of pores affect the engineering properties. As a first approximation, the total porosity affects the mechanical behavior, whereas the size...

  4. Heat treatment furnace

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Effects of sintering temperature on the density and porosity

    African Journals Online (AJOL)

    2013-03-01

    Mar 1, 2013 ... Abstract. Effects of sintering temperature on the density and porosity of sodium chloride preforms for alu- minium foam manufacturing have been investigated. Cold pressed salt preforms were sintered at. 730Й, 760Й and 790Й and different times ranging between 6- 18 hours in a carbolite furnace at.

  6. Effects of Sintering Temperature on the Density And Porosity of ...

    African Journals Online (AJOL)

    Effects of sintering temperature on the density and porosity of sodium chloride preforms for alu- minium foam manufacturing have been investigated. Cold pressed salt preforms were sintered at 30, 760 and 790 and di erent times ranging between 6- 18 hours in a carbolite furnace at a heating rate of 5/minute. The Results of ...

  7. Analyses of laser and furnace treated sol-gel coatings

    NARCIS (Netherlands)

    De Hosson, JT; De Haas, M; Sudarshan, TS; Jeandin, M; Khor, KA

    1998-01-01

    Here we explore a new method that allows thin films to be made with almost any composition and degree of porosity by means of a combination of sol-gel and laser technology. Results are presented for furnace and laser treated TEOTI-(tetraethylorthotitanate as sol precursor) coated silicon samples.

  8. 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)

  9. 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

  10. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    OpenAIRE

    Panic B.

    2017-01-01

    The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas c...

  11. Porosity variation in chalk

    DEFF Research Database (Denmark)

    Lind, Ida; Grøn, Peter

    1996-01-01

    Vertical porosity variations in chalk are generally assumed to result from either a vaguely defined combination of primary sedimentary and diagenetic processes or solely to diagenetic processes. In this study, image analysis of backscatter electron images of polished samples and geochemical...

  12. Microparticles with hierarchical porosity

    Science.gov (United States)

    Petsev, Dimiter N; Atanassov, Plamen; Pylypenko, Svitlana; Carroll, Nick; Olson, Tim

    2012-12-18

    The present disclosure provides oxide microparticles with engineered hierarchical porosity and methods of manufacturing the same. Also described are structures that are formed by templating, impregnating, and/or precipitating the oxide microparticles and method for forming the same. Suitable applications include catalysts, electrocatalysts, electrocatalysts support materials, capacitors, drug delivery systems, sensors and chromatography.

  13. FURNACES OF ROTARY HEATING

    Directory of Open Access Journals (Sweden)

    S. L. Ровин

    2004-01-01

    Full Text Available In the article there are analyzed the different ways of thermal treatment and melting of polydisperse materials and there are presented the developed by authors original coaxial-cylinder furnace settings, allowing to increase considerably the efficiency and productivity of technological process.  

  14. Silica crown refractory corrosion in glass melting furnaces

    OpenAIRE

    Balandis A.; Nizeviciene D.

    2011-01-01

    The critical parameters of silica refractories, such as compressive strength, bulk, density, quantity of silica, microstructure and porosity were evaluated of unused and used bricks to line the crowns of glass furnaces, when the rate of corrosion of crowns were about 2 times greater. The change of these parameters, the chemical composition and formation of the microcracks in the used silica refractories material were studied. It was established that the short time at service of containe...

  15. Liquids with permanent porosity

    Science.gov (United States)

    Giri, Nicola; Del Pópolo, Mario G.; Melaugh, Gavin; Greenaway, Rebecca L.; Rätzke, Klaus; Koschine, Tönjes; Pison, Laure; Gomes, Margarida F. Costa; Cooper, Andrew I.; James, Stuart L.

    2015-11-01

    Porous solids such as zeolites and metal-organic frameworks are useful in molecular separation and in catalysis, but their solid nature can impose limitations. For example, liquid solvents, rather than porous solids, are the most mature technology for post-combustion capture of carbon dioxide because liquid circulation systems are more easily retrofitted to existing plants. Solid porous adsorbents offer major benefits, such as lower energy penalties in adsorption-desorption cycles, but they are difficult to implement in conventional flow processes. Materials that combine the properties of fluidity and permanent porosity could therefore offer technological advantages, but permanent porosity is not associated with conventional liquids. Here we report free-flowing liquids whose bulk properties are determined by their permanent porosity. To achieve this, we designed cage molecules that provide a well-defined pore space and that are highly soluble in solvents whose molecules are too large to enter the pores. The concentration of unoccupied cages can thus be around 500 times greater than in other molecular solutions that contain cavities, resulting in a marked change in bulk properties, such as an eightfold increase in the solubility of methane gas. Our results provide the basis for development of a new class of functional porous materials for chemical processes, and we present a one-step, multigram scale-up route for highly soluble ‘scrambled’ porous cages prepared from a mixture of commercially available reagents. The unifying design principle for these materials is the avoidance of functional groups that can penetrate into the molecular cage cavities.

  16. Porosity and Health: Perspective of Traditional Persian Medicine.

    Science.gov (United States)

    Tafazoli, Vahid; Nimrouzi, Majid; Daneshfard, Babak

    2016-05-01

    The authors of this manuscript aimed to show the importance of porosity and condensation in health according to traditional Persian medicine (TPM) with consideration of new evidence in conventional medicine. Cardinal traditional medical and pharmacological texts were searched for the traditional terms of takhalkhol (porosity) and takassof (condensity) focused on preventive methods. The findings were classified and compared with new medical findings. According to traditional Persian medicine, porosity and condensity are the two crucial items that contribute to human health. Somatotype is a taxonomy based on embryonic development, which may be considered in parallel with porosity and condensation. However, these terms are not completely the same. There are many causes for acquired porosity comprising hot weather, too much intercourse, rage, starvation, and heavy exercises. In general, porosity increases the risk of diseases as it makes the body organs vulnerable to external hot and cold weather. On the other hand, the porose organs are more susceptible to accumulation of morbid matters because the cellular wastes cannot be evacuated in the normal way. There are some common points between traditional and conventional medicine in the context of porosity and condensity. The relation between diet and somatotype is an example. Condensity and porosity are the two basic items cited in the TPM resources and contribute to health maintenance and disease prevention of body organs. Creating a balance between these two states in different body organs, strongly contributes to disease prevention, treatment and diminishing chronic diseases period. Choosing proper modality including diet, drug therapy, and manual therapy depends on the amount porosity and stiffness of the considered organ and the preferred porosity of the affected organ keeping in a normal healthy state.

  17. 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.

  18. Furnace brazing under partial vacuum

    Science.gov (United States)

    Mckown, R. D.

    1979-01-01

    Brazing furnace utilizing partial-vacuum technique reduces tooling requirements and produces better bond. Benefit in that partial vacuum helps to dissociate metal oxides that inhibit metal flow and eliminates heavy tooling required to hold parts together during brazing.

  19. Review of furnace modeling

    Energy Technology Data Exchange (ETDEWEB)

    Krishna, C. R.

    1978-06-01

    There has been a spurt of recent activity in developing and applying numerical modeling to combustors and furnaces. The purpose of this review is to provide a brief overview of these recent developments and draw conclusions on the scope for further work in the area of modeling. A brief qualitative review of the various models that have been developed is presented. The models show a progressive recognition of the complexity of turbulence-chemistry interactions and attempts to include more recent submodels of such interactions. There are attempts to incorporate the three-dimensional character of fluid flows and solve the elliptic equations arising in recirculating flows. Flux models of radiation transfer are being included in the energy transport equations. Efficient numerical algorithms are being developd to solve the finite difference form of a set of elliptic, partial differential equations. The test of the success of modeling lies, obviously, in comparison with experimental measurements. Such experiments are being undertaken, but, the techniques of measurements also need development before detailed comparison can be made. The measurements made seem to indicate qualitative agreement of model predictions with limited laboratory measurements. It is concluded from the review that there is still need for development in several areas including turbulence (and turbulence-chemistry interactions) modeling, liquid and solid fuel introduction, interaction with the flow and combustion, models for soot formation, and experimental validation.

  20. Fossil fuel furnace reactor

    Science.gov (United States)

    Parkinson, William J.

    1987-01-01

    A fossil fuel furnace reactor is provided for simulating a continuous processing plant with a batch reactor. An internal reaction vessel contains a batch of shale oil, with the vessel having a relatively thin wall thickness for a heat transfer rate effective to simulate a process temperature history in the selected continuous processing plant. A heater jacket is disposed about the reactor vessel and defines a number of independent controllable temperature zones axially spaced along the reaction vessel. Each temperature zone can be energized to simulate a time-temperature history of process material through the continuous plant. A pressure vessel contains both the heater jacket and the reaction vessel at an operating pressure functionally selected to simulate the continuous processing plant. The process yield from the oil shale may be used as feedback information to software simulating operation of the continuous plant to provide operating parameters, i.e., temperature profiles, ambient atmosphere, operating pressure, material feed rates, etc., for simulation in the batch reactor.

  1. Silica crown refractory corrosion in glass melting furnaces

    Directory of Open Access Journals (Sweden)

    Balandis A.

    2011-01-01

    Full Text Available The critical parameters of silica refractories, such as compressive strength, bulk, density, quantity of silica, microstructure and porosity were evaluated of unused and used bricks to line the crowns of glass furnaces, when the rate of corrosion of crowns were about 2 times greater. The change of these parameters, the chemical composition and formation of the microcracks in the used silica refractories material were studied. It was established that the short time at service of container glass furnace crown can be related to low quality of silica brick: high quantity of CaO and impurities, low quantity of silica, low quantity of silica, transferred to tridymite and cristobalite and formation of 5-10 μm and more than 100 μm cracks in the crown material. The main reason of corrosion high quality silica bricks used to line the crown of electrovacuum glass furnace is the multiple cyclic change of crown temperature at 1405 - 1430°C range in the initial zone of crown and at 1575 - 1605°C range in the zone of highest temperatures.

  2. High Efficiency Solar Furnace Core Project

    Data.gov (United States)

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

  3. 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

  4. Training Guidelines: Glass Furnace Operators.

    Science.gov (United States)

    Ceramics, Glass, and Mineral Products Industry Training Board, Harrow (England).

    Technological development in the glass industry is constantly directed towards producing high quality glass at low operating costs. Particularly, changes have taken place in melting methods which mean that the modern furnace operator has greater responsibilities than any of his predecessors. The complexity of control systems, melting rates, tank…

  5. Characterization of calcium carbonate sorbent particle in furnace environment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Soo [Aerosol and Particle Technology Laboratory, Department of Mechanical Engineering, KAIST 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of); Jung, Jae Hee [Environment Sensor System Research Center, KIST 39-1 Hawolgok-dong, Seongbuk-gu, Seoul, 136-791 (Korea, Republic of); Keel, Sang In; Yun, Jin Han; Min, Tai Jin [Environmental Systems Research Division, KIMM 104 Sinseongno, Yuseong-gu, Daejeon, 305-343 (Korea, Republic of); Kim, Sang Soo, E-mail: sskim@kaist.ac.kr [Aerosol and Particle Technology Laboratory, Department of Mechanical Engineering, KAIST 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 (Korea, Republic of)

    2012-07-01

    The oxy-fuel combustion system is a promising technology to control CO{sub 2} and NO{sub X} emissions. Furthermore, sulfation reaction mechanism under CO{sub 2}-rich atmospheric condition in a furnace may lead to in-furnace desulfurization. In the present study, we evaluated characteristics of calcium carbonate (CaCO{sub 3}) sorbent particles under different atmospheric conditions. To examine the physical/chemical characteristics of CaCO{sub 3}, which is used as a sorbent particle for in-furnace desulfurization in the oxy-fuel combustion system, they were injected into high temperature drop tube furnace (DTF). Experiments were conducted at varying temperatures, residence times, and atmospheric conditions in a reactor. To evaluate the aerosolizing characteristics of the CaCO{sub 3} sorbent particle, changes in the size distribution and total particle concentration between the DTF inlet and outlet were measured. Structural changes (e.g., porosity, grain size, and morphology) of the calcined sorbent particles were estimated by BET/BJH, XRD, and SEM analyses. It was shown that sorbent particles rapidly calcined and sintered in the air atmosphere, whereas calcination was delayed in the CO{sub 2} atmosphere due to the higher CO{sub 2} partial pressure. Instead, the sintering effect was dominant in the CO{sub 2} atmosphere early in the reaction. Based on the SEM images, it was shown that the reactions of sorbent particles could be explained as a grain-subgrain structure model in both the air and CO{sub 2} atmospheres.

  6. A Model of Network Porosity

    Science.gov (United States)

    2016-11-09

    standpoint remains more of an art than a science . Even when well executed, the ongoing evolution of the network may violate initial, security-critical design...from a security standpoint remains more of an art than a science . Even when well executed, the ongoing evolution of the network may violate initial...is outside the scope of this paper. As such, we focus on event probabilities. The output of the network porosity model is a stream of timestamped

  7. 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.

  8. Brazilian urban porosity : Treat or threat?

    NARCIS (Netherlands)

    Moreno Pessoa, I.; Tasan-Kok, M.T.; Korthals Altes, W.K.

    2016-01-01

    Urban areas have spatial discontinuities, such as disconnected neighbourhoods, brownfield areas and leftover places. They can be captured by the metaphor of urban porosity. This paper aims to highlight the potential social consequences of urban porosity by creating a ‘porosity index’. The authors

  9. Preparation of Ceramic-Bonded Carbon Block for Blast Furnace

    Science.gov (United States)

    Li, Yiwei; Li, Yawei; Sang, Shaobai; Chen, Xilai; Zhao, Lei; Li, Yuanbing; Li, Shujing

    2014-01-01

    Traditional carbon blocks for blast furnaces are mainly produced with electrically calcined anthracite owing to its good hot metal corrosion resistance. However, this kind of material shows low thermal conductivity and does not meet the demands for cooling of the hearth and the bottom of blast furnaces. In this article, a new kind of a high-performance carbon block has been prepared via ceramic-bonded carbon (CBC) technology in a coke bed at 1673 K (1400 °C) using artificial graphite aggregate, alumina, metallic aluminum, and silicon powders as starting materials. The results showed that artificial graphite aggregates were strongly bonded by the three-dimensional network of ceramic phases in carbon blocks. In this case, the good resistance of the CBC blocks against erosion/corrosion by the hot metal is provided by the ceramic matrix and the high thermal conductivity by the graphite aggregates. The microstructure of this carbon block resembles that of CBC composites with a mean pore size of less than 0.1 μm, and up to 90 pct of the porosity shows a pore size <1 μm. Its thermal conductivity is higher than 30 W · m-1 · K-1 [293 K (20 °C)]. Meanwhile, its hot metal corrosion resistance is better than that of traditional carbon blocks.

  10. Measurement of airflow in residential furnaces

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-24

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

  11. 3D Model Studies on the Effect of Bed and Powder Type Upon Radial Static Pressure and Powder Distribution in Metallurgical Shaft Furnaces

    Directory of Open Access Journals (Sweden)

    Panic B.

    2017-09-01

    Full Text Available The flow of gases in metallurgical shaft furnaces has a decisive influence on the course and process efficiency. Radial changes in porosity of the bed cause uneven flow of gas along the radius of the reactor, which sometimes is deliberate and intentional. However, holdup of solid particles in descending packed beds of metallurgical shaft furnaces can lead to unintentional changes in porosity of the bed along the radial reactor. Unintentional changes in porosity often disrupt the flow of gas causing poor performance of the furnace. Such disruptions of flow may occur in the blast furnace due to high level of powder content in gas caused by large amount of coal dust/powder insufflated as fuel substitute. The paper describes the model test results of radial distribution of static pressure and powder hold up within metallurgical reactor. The measurements were carried out with the use of 3D physical model of two-phase flow gas-powder in the moving (descending packed bed. Sinter or blast furnace pellets were used as packed bed while carbon powder or iron powder were used as the powder. Wide diversity within both static pressure distribution and powder distribution along the radius of the reactor were observed once the change in the type of powder occurred.

  12. Acoustics of a Mixed Porosity Felt Airfoil

    Science.gov (United States)

    2016-06-06

    NUWC-NPT Technical Report 12,212 6 June 2016 Acoustics of a Mixed Porosity Felt Airfoil Aren M. Hellum Undersea Warfare Weapons...Research project “ Acoustics and Performance of Lifting Surfaces with Mixed Porosity.” The technical reviewer for this report was Dr. Jesse Belden...MM-YYYY) 06-06-2016 2. REPORT TYPE Technical Report 3. DATES COVERED (From – To) 4. TITLE AND SUBTITLE Acoustics of a Mixed Porosity

  13. Measuring tablet porosity using multispectral imaging system

    Science.gov (United States)

    Nippolainen, Ervin; Ervasti, Tuomas; Ketolainen, Jarkko; Kamshilin, Alexei A.

    2010-05-01

    A multispectral imaging system with computer controlled light source of 16 light emitting diodes is applied for measuring of tablet porosity. The system is based on a subspace vector model of surface reflection. The measured spectral data are compressed on the stage of measurement and used directly for the discrimination of tablets with different porosity. The experimental results demonstrate that the multispectral imaging system is a potential method for tablet porosity measurement.

  14. Materials treatment at solar furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, D.

    2002-07-01

    In the modern age, beginning in the fifties, solar furnaces have been used as a tool for research in materials technologies and treatment, as well as chemical reactor test beds. However, this is not the first time man has attempted to use sunlight as a means of manipulating the materials that surround us. During the Renaissance, Leonardo da Vinci proposed the construction of a six-kilometer parabolic mirror able to heat any boiler for a dye factory and the sculptor Andrea del Verrochio used a solar mirror to weld the parts of a spherical copper support for a lantern at Santa Maria del Fiore in Florence. At present, the materials treatment work in solar furnaces may be summarized as follows: the study of physical-thermal properties of materials at high temperatures-innovative treatments impossible to carry out with the conventional manufacturing processes, which improve certain properties of materials that are going to work under very severe conditions improving the results of industrial materials treatments such as laser surface tempering testing under laboratory conditions of materials which will have to undergo extreme conditions at high temperatures (ceramic coating of aircraft and space vehicles, turbine blades, power brake discs, electrical contacts, nuclear reactors, etc.) With regard to high temperature chemical applications, experiments are being carried out in detoxification, gasification of solid fuels, chemical reaction kinetics studies and direct absorption particle reactors. (Author) 31 refs.

  15. Materials treatment at Solar Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, D. [Ciemat. Plataforma Solar de Almeria. Almeria (Spain)

    2000-07-01

    In the modern age, beginning in the fifties, solar furnaces have been used as a tool for research in materials technologies and treatment, as well as chemical reactor test beds. However, this is not the first time man has attempted to use sunlight as a means of manipulating the materials that surround us. During the Renaissance, Leonardo da Vinci proposed the construction of a six-kilometer parabolic mirror able to heat any boiler for a dye factory and the sculptor Andrea del Verrochio used a solar mirror to weld the parts of a spherical copper support for a lantern at Santa Maria del Fiore in Florence. At present, the materials treatment work in solar furnaces may be summarized as follows: -the study of physical-thermal properties of materials at high temperatures -innovative treatments impossible to carry out with the conventional manufacturing processes, which improve certain properties of materials that are going to work under very severe conditions -improving the results of industrial materials treatments such as laser surface tempering -testing under laboratory conditions of materials which will have to undergo extreme conditions at high temperatures (ceramic coating of aircraft and space vehicles, turbine blades, power brake discs, electrical contacts, nuclear reactors, etc.) With regard to high temperature chemical applications, experiments are being carried out in detoxification, gasification of solid fuels, chemical reaction kinetics studies and direct absorption particle reactors. (Author) 31 refs.

  16. Refractory of Furnaces to Reduce Environmental Impact

    Energy Technology Data Exchange (ETDEWEB)

    Hanzawa, Shigeru, E-mail: hanzawa@ngk.co.jp [NGK Insulators, LTD., Mizuho, Nagoya (Japan)

    2011-10-29

    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{sub 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{sub 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.

  17. Acoustic characteristics of electric arc furnaces

    Science.gov (United States)

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

    2016-06-01

    A mathematical model is constructed to describe the appearance and development of the noise characteristics of superpower electric arc furnaces. The noise formation is shown to be related to the pulsation of the axial plasma flows in arc discharges because of the electrodynamic pressure oscillations caused by the interaction of the self-magnetic field with the current passing in an arc. The pressure in the arc axis changes at a frequency of 100 Hz at the maximum operating pressure of 66 kPa for an arc current of 80 kA. The main ac arc sound frequencies are multiples of 100 Hz, which is supported in the practice of operation of electric arc furnaces. The sound intensity in the furnace laboratory reaches 160 dB and is decreased to 115-120 dB in the working furnace area due to shielding by the furnace jacket, the molten metal, and the molten slag. The appropriateness of increasing the hermetic sealing of electric furnaces and creating furnaces operating at low currents and high transformer voltages is corroborated.

  18. Porosity Prediction of Plain Weft Knitted Fabrics

    Directory of Open Access Journals (Sweden)

    Muhammad Owais Raza Siddiqui

    2014-12-01

    Full Text Available Wearing comfort of clothing is dependent on air permeability, moisture absorbency and wicking properties of fabric, which are related to the porosity of fabric. In this work, a plug-in is developed using Python script and incorporated in Abaqus/CAE for the prediction of porosity of plain weft knitted fabrics. The Plug-in is able to automatically generate 3D solid and multifilament weft knitted fabric models and accurately determine the porosity of fabrics in two steps. In this work, plain weft knitted fabrics made of monofilament, multifilament and spun yarn made of staple fibers were used to evaluate the effectiveness of the developed plug-in. In the case of staple fiber yarn, intra yarn porosity was considered in the calculation of porosity. The first step is to develop a 3D geometrical model of plain weft knitted fabric and the second step is to calculate the porosity of the fabric by using the geometrical parameter of 3D weft knitted fabric model generated in step one. The predicted porosity of plain weft knitted fabric is extracted in the second step and is displayed in the message area. The predicted results obtained from the plug-in have been compared with the experimental results obtained from previously developed models; they agreed well.

  19. Cast construction elements for heat treatment furnaces

    Directory of Open Access Journals (Sweden)

    B. Piekarski

    2011-07-01

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

  20. Blast furnace supervision and control system

    Energy Technology Data Exchange (ETDEWEB)

    Remorino, M.; Lingiardi, O.; Zecchi, M. [Siderar S.A.I.C./Ingdesi, San Nicolas (Argentina)

    1997-12-31

    On December 1992, a group of companies headed by Techint, took over Somisa, the state-owned integrated steel plant located at San Nicolas, Province of Buenos Aires, Argentina, culminating an ambitious government privatization scheme. The blast furnace 2 went into a full reconstruction and relining in January 1995. After a 140 MU$ investment the new blast furnace 2 was started in September 1995. After more than one year of operation of the blast furnace the system has proven itself useful and reliable. The main reasons for the success of the system are: same use interface for all blast furnace areas -- operation, process, maintenance and management, (full horizontal and vertical integration); and full accessibility to all information and process tools though some restrictions apply to field commands (people empowerment). The paper describes the central system.

  1. Multiple hearth furnace for reducing iron oxide

    Energy Technology Data Exchange (ETDEWEB)

    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).

  2. Chamberless residential warm air furnace design

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-07-01

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

  3. METALLURGICAL ADVANTAGES OF ROTATION TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2010-01-01

    Full Text Available It is shown that introduction of rotary tilting furnaces can be a basis for considerable resources saving, lowering of power inputs, reduction of products cost for Byelorussian machine-building enterprises.

  4. Modular Distributed Concentrator for Solar Furnace Project

    Data.gov (United States)

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

  5. 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.

  6. Waste and dust utilisation in shaft furnaces

    OpenAIRE

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

    2005-01-01

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

  7. 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.

  8. Information modeling system for blast furnace control

    Science.gov (United States)

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

    2016-09-01

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

  9. Fabrication of dual porosity electrode structure

    Science.gov (United States)

    Smith, J.L.; Kucera, E.H.

    1991-02-12

    A substantially entirely fibrous ceramic is described which may have dual porosity of both micro and macro pores. Total porosity may be 60-75% by volume. A method of spraying a slurry perpendicularly to an ambient stream of air is disclosed along with a method of removing binders without altering the fiber morphology. Adding fine ceramic particulates to the green ceramic fibers enhances the sintering characteristics of the fibers. 3 figures.

  10. Heat and mass transfer in a vertical flue ring furnace

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Mona

    1997-12-31

    The main emphasis of this thesis was the design of a mathematical simulation model for studying details in the baking of anodes in the Hydro Aluminium anode baking furnace. The change of thermal conductivity, density, porosity and permeability during heat treatment was investigated. The Transient Plane Source technique for measuring thermal conductivity of solids was used on green carbon materials during the baking process in the temperature range 20-600 {sup o}C. Next, change of mass, density, porosity and permeability of anode samples were measured after being baked to temperatures between 300 and 1200 {sup o}C. The experimental data were used for parameter estimation and verification of property models for use in the anode baking models. Two distinct mathematical models have been modified to study the anode baking. A transient one-dimensional model for studying temperature, pressure and gas evolution in porous anodes during baking was developed. This was extended to a two-dimensional model incorporating the flue gas flow. The mathematical model which included porous heat and mass transfer, pitch pyrolysis, combustion of volatiles, radiation and turbulent channel flow, was developed by source code modification of the Computational Fluid Dynamics code FLUENT. The two-dimensional geometry of a flue gas channel adjacent to a porous flue gas wall, packing coke and anode was used for studying the effect of different firing strategies, raw materials properties and packing coke thickness. The model proved useful for studying the effects of heating rate, geometry and anode properties. 152 refs., 73 figs, 11 tabs.

  11. 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,

  12. Quantifying porosity, compressibility and permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Frykman, Peter

    The Fjerritslev Formation in the Norwegian-Danish Basin forms the main seal to Upper Triassic-Lower Jurassic sandstone reservoirs. In order to estimate rock properties Jurassic shale samples from deep onshore wells in Danish basin were studied. Mineralogical analysis based on X-ray diffractometry...... (XRD) of shale samples show about 50% silt and high content of kaolinite in the clay fraction when compared with offshore samples from the Central Graben. Porosity measurements from helium porosimetry-mercury immersion (HPMI), mercury injection capillary pressure (MICP) and nuclear magnetic resonance...... (NMR) show that, the MICP porosity is 9-10% points lower than HPMI and NMR porosity. Compressibility result shows that deep shale is stiffer in situ than normally assumed in geotechnical modelling and that static compressibility corresponds with dynamic one only at the begining of unloading stress...

  13. Plant fibre composites - porosity and stiffness

    DEFF Research Database (Denmark)

    Madsen, Bo; Thygesen, Anders; Lilholt, Hans

    2009-01-01

    Plant fibre composites contain typically a relatively large amount of porosity which influences their performance. A model, based on a modified rule of mixtures, is presented to include the influence of porosity on the composite stiffness. The model integrates the volumetric composition...... of the composites with their mechanical properties. The fibre weight fraction is used as an independent parameter to calculate the complete volumetric composition. A maximum obtainable stiffness of the composites is calculated at a certain transition fibre weight fraction, which is characterised by a best possible...... combination of high fibre volume fraction and low porosity. The model is validated with experimental data from the literature on several types of composites. A stiffness diagram is presented to demonstrate that the calculations can be used for tailoring and design of composites with a given profile...

  14. 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.

  15. Cogeneration from glass furnace waste heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Hnat, J.G.; Cutting, J.C.; Patten, J.S.

    1982-06-01

    In glass manufacturing 70% of the total energy utilized is consumed in the melting process. Three basic furnaces are in use: regenerative, recuperative, and direct fired design. The present paper focuses on secondary heat recovery from regenerative furnaces. A diagram of a typical regenerative furnace is given. Three recovery bottoming cycles were evaluated as part of a comparative systems analysis: steam Rankine Cycle (SRC), Organic Rankine Cycle (ORC), and pressurized Brayton cycle. Each cycle is defined and schematicized. The net power capabilities of the three different systems are summarized. Cost comparisons and payback period comparisons are made. Organic Rankine cycle provides the best opportunity for cogeneration for all the flue gas mass flow rates considered. With high temperatures, the Brayton cycle has the shortest payback period potential, but site-specific economics need to be considered.

  16. Production of durable expanded perlite microspheres in a Vertical Electrical Furnace

    Science.gov (United States)

    Panagiotis, M.; Angelopoulos, P.; Taxiarchou, M.; Paspaliaris, I.

    2016-04-01

    Expanded perlite constitutes one of the most competitive insulating materials that is widely used in construction and manufacturing industry due to its unique properties combination; it is white, natural, lightweight, chemically inert, and exhibits superior insulating properties (thermal and acoustic) and fire resistance. Conventionally, perlite expansion is performed in vertical gas-fired furnaces; the conventional perlite expansion process has certain disadvantages which affect expanded products quality, thus limiting their performance and range of applications. In order to overcome the drawbacks of the conventional expansion technique, a new perlite expansion process has been designed based on a vertical electrical furnace (VEF). In the current study, fine perlite samples (-150 μm) from Milos Island, Greece, were expansed in the novel VEF and a conventional gas-fired furnace with the aim to evaluate and compare the main physical properties of the expanded products. The novel expanded perlite particles were characterised by superior properties, namely increased compression strength, competitive water and oil absorption capability, size homogeneity, spherical shape and decreased surface porosity in comparison to conventionally expanded samples.

  17. High-porosity Cenozoic carbonate rocks of South Florida: Progressive loss of porosity with depth

    Science.gov (United States)

    Halley, Robert B.; Schmoker, James W.

    1983-01-01

    Porosity measurements by borehole gravity meter in subsurface Cenozoic carbonates of south Florida reveal an extremely porous mass of limestone and dolomite which is transitional in total pore volume between typical porosity values for modern carbonate sediments and ancient carbonate rocks. A persistent decrease of porosity with depth, similar to that of chalks of the Gulf Coast, occurs in these rocks. We make no attempt to differentiate depositional or diagenetic facies which produce scatter in the porosity-depth relationship; the dominant data trends thus are functions of carbonate rocks in general rather than of particular carbonate facies. Carbonate strata with less than 20% porosity are absent from the rocks studied here.Aquifers and aquicludes cannot be distinguished on the basis of porosity. Although aquifers are characterized by great permeability and well-developed vuggy and even cavernous porosity in some intervals, they are not exceptionally porous when compared to other Tertiary carbonate rocks in south Florida. Permeability in these strata is governed more by the spacial distribution of pore space and matrix than by the total volume of porosity present.Dolomite is as porous as, or slightly less porous than, limestones in these rocks. This observation places limits on any model proposed for dolomitization and suggests that dolomitization does not take place by a simple ion-for-ion replacement of magnesium for calcium. Dolomitization may be selective for less porous limestone, or it may involve the incorporation of significant amounts of carbonate as well as magnesium into the rock.The great volume of pore space in these rocks serves to highlight the inefficiency of early diagenesis in reducing carbonate porosity and to emphasize the importance of later porosity reduction which occurs during the burial or late near-surface history of limestones and dolomites.

  18. Gas-solid reaction with porosity change

    Directory of Open Access Journals (Sweden)

    Ivar Stakgold

    2000-10-01

    Full Text Available For a gas diffusing through a porous solid and reacting with it isothermally and irreversibly, the mathematical formulation consists of a nonlinear parabolic PDE for the gas concentration coupled with an ODE for the solid concentration. Under the assumption of constant porosity, a fairly complete analysis was provided by Diaz and Stakgold, [3]. Here some of the results are extended to the case when the porosity increases as the solid is consumed. In particular, estimates are given for the time to full conversion of the solid when the reaction rate is proportional to the product of the gas concentration and a fractional power of the solid concentration.

  19. Permeability-porosity relationships in sedimentary rocks

    Science.gov (United States)

    Nelson, Philip H.

    1994-01-01

    In many consolidated sandstone and carbonate formations, plots of core data show that the logarithm of permeability (k) is often linearly proportional to porosity (??). The slope, intercept, and degree of scatter of these log(k)-?? trends vary from formation to formation, and these variations are attributed to differences in initial grain size and sorting, diagenetic history, and compaction history. In unconsolidated sands, better sorting systematically increases both permeability and porosity. In sands and sandstones, an increase in gravel and coarse grain size content causes k to increase even while decreasing ??. Diagenetic minerals in the pore space of sandstones, such as cement and some clay types, tend to decrease log(k) proportionately as ?? decreases. Models to predict permeability from porosity and other measurable rock parameters fall into three classes based on either grain, surface area, or pore dimension considerations. (Models that directly incorporate well log measurements but have no particular theoretical underpinnings from a fourth class.) Grain-based models show permeability proportional to the square of grain size times porosity raised to (roughly) the fifth power, with grain sorting as an additional parameter. Surface-area models show permeability proportional to the inverse square of pore surface area times porosity raised to (roughly) the fourth power; measures of surface area include irreducible water saturation and nuclear magnetic resonance. Pore-dimension models show permeability proportional to the square of a pore dimension times porosity raised to a power of (roughly) two and produce curves of constant pore size that transgress the linear data trends on a log(k)-?? plot. The pore dimension is obtained from mercury injection measurements and is interpreted as the pore opening size of some interconnected fraction of the pore system. The linear log(k)-?? data trends cut the curves of constant pore size from the pore-dimension models

  20. 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.

  1. 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.

  2. 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.

  3. ROTARY FURNACES FOR THERMAL PROCESSING AND DRYING OF POLYDISPERSE MATERIALS

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2006-01-01

    Full Text Available It is shown that rotary furnaces and drying ovens are a perspective type of furnaces, allowing to solve a number of problems in conditions of flexible production and strong resources economy

  4. Optimization and Development of Swellable Controlled Porosity ...

    African Journals Online (AJOL)

    Purpose: To develop swellable controlled porosity osmotic pump tablet of theophylline and to define the formulation and process variables responsible for drug release by applying statistical optimization technique. Methods: Formulations were prepared based on Taguchi Orthogonal Array design and Fraction Factorial ...

  5. INVESTIGATIONS ON OPERATION OF ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

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

  6. Energy Saving Devices on Gas Furnaces.

    Science.gov (United States)

    1980-03-01

    DEVICES FOR GAS FURNACES THOMAS E. BRISBANE ,o"’ P. B. SHEPHERD JOHNS-MANVILLE SALES CORPORATION RESEARCH & DEVELOPMENT CENTER KEN- CARYL RANCH, DENVER...by Mr. Thomas E. Brisbane under the direction of Dr. S. Karaki, Professor of Civil Engineering and Director, Solar Energy Application Laboratory. Mr

  7. Protecting brazing furnaces from air leaks

    Science.gov (United States)

    Armenoff, C. T.; Mckown, R. D.

    1980-01-01

    Inexpensive inert-atmosphere shielding protects vacuum brazing-furnace components that are likely to spring leak. Pipefittings, gages, and valves are encased in transparent plastic shroud inflated with argon. If leak develops, harmless argon will enter vacuum chamber, making it possible to finish ongoing brazing or heat treatment before shutting down for repair.

  8. Calibration procedure for fire resistance furnaces

    NARCIS (Netherlands)

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

    1996-01-01

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

  9. REACTIVATION OF FERRIC OXIDES IN ROTARY FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2011-01-01

    Full Text Available The advantages of rotary furnaces, developed by specialists of GGTU named after P. O. Suhoj and UP «Tehnolit» for carrying out of ferric oxide recycling with regard to conditions of the Republic of Belarus, are described.

  10. 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.

  11. Design and Testing of a Cupola Furnace for Micheal Okpara ...

    African Journals Online (AJOL)

    ... for the present study. It is thus recommended that this novelty design be used as a foundation for building bigger furnaces and for the sensitisation of students' awareness in foundry technology and practices. Keywords: furnace lining, refractory materials, critical radius of insulation, furnace fuel, heat transfer, cupola zones ...

  12. 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.

  13. AUTOMATION OF GLASS TEMPERING FURNACE BY USING PLC

    Directory of Open Access Journals (Sweden)

    Abdullah BÜYÜKYILDIZ

    2007-02-01

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

  14. Air filled porosity in composting processes

    Energy Technology Data Exchange (ETDEWEB)

    Ruggieri, L.; Gea, T.; Artola, A.; Sanchez, A.

    2009-07-01

    As it is widely known, the composting process consists in the aerobic decomposition of the biodegradable organic matter present in different types of solid wastes. Water and oxygen are necessary for the biological activity of microorganisms involved in the composting process and their availability is directly related to the total and the air filled porosity (AFP). Maintaining adequate AFP level satisfies the oxygen content requirement to achieve the desired composting conditions and thus, tho enhance biological activity. (Author)

  15. Soil plasticity with a different porosity

    Directory of Open Access Journals (Sweden)

    Klovanych Sergii

    2017-01-01

    Full Text Available The model of soils with different porosity in the framework of the associated theory of plasticity is presented The single analytical function describes the loading surface in the stress space. The deformational hardening/softening and the phenomenon of dilatancy during plastic flow are incorporated in the model. The triaxial compression tests are simulated and compared with the experimental results for different values of the void ratio and initial hydrostatic stresses.

  16. Reducing the open porosity of pyroboroncarbon articles

    Science.gov (United States)

    Martyushov, G. G.; Zakharevich, A. M.; Pichkhidze, S. Ya.; Koshuro, V. A.

    2016-02-01

    It is established that a decrease in the open porosity of pyroboroncarbon, a pyrolytic glassy composite material of interest for manufacturing prosthetic heart valves (PHVs), can be achieved via impregnation of articles with an alcohol solution of 3-aminopropyltriethoxysilane and subsequent thermal treatment. The maximum roughness height and linear size of open pores on the surface of PHV parts made of pyroboroncarbon can additionally be reduced by final mechanical processing of a silicon oxide film formed on the surface.

  17. Mathematical aspects of multi-porosity continua

    CERN Document Server

    Straughan, Brian

    2017-01-01

    This book is devoted to describing theories for porous media where such pores have an inbuilt macro structure and a micro structure. For example, a double porosity material has pores on a macro scale, but additionally there are cracks or fissures in the solid skeleton. The actual body is allowed to deform and thus the underlying theory is one of elasticity. Various different descriptions are reviewed. Chapter 1 introduces the classical linear theory of elastodynamics together with uniqueness and continuous dependence results. Chapters 2 and 3 review developments of theories for double and triple porosity using a pressure-displacement structure and also using voids-displacement. Chapter 4 compares various aspects of the pressure-displacement and voids-displacement theories via uniqueness studies and wave motion analysis. Mathematical analyses of double and triple porosity materials are included concentrating on uniqueness and stability studies in chapters 5 to 7. In chapters 8 and 9 the emphasis is on wa...

  18. GAS MOVEMENT IN ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available The article presents the results of studies of gas movement and heat and mass transfer processes in the rotary tilting furnace (RTF at the heat treatment of disperse materials. The study was performed through computer modeling using software packages ANSYS CFX and Solid Works Flow Simulation. The results were used to design RTF with different capacity and application and helped to improve their technical and economic characteristics.

  19. Influence of Chemical Composition on Porosity in Aluminium Alloys

    OpenAIRE

    Kucharčík L.; Brůna M.; Sládek A.

    2014-01-01

    Porosity is one of the major defects in aluminum castings, which results is a decrease of a mechanical properties. Porosity in aluminum alloys is caused by solidification shrinkage and gas segregation. The final amount of porosity in aluminium castings is mostly influenced by several factors, as amount of hydrogen in molten aluminium alloy, cooling rate, melt temperature, mold material, or solidification interval. This article deals with effect of chemical composition on porosity in Al-Si alu...

  20. Mechanical properties and porosity of polylactide for biomedical applications

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Schroën, C.G.P.H.; Boom, R.M.

    2008-01-01

    In this study, the strength, ductility, and porosity of polylactide films prepared by immersion precipitation and film casting in air were investigated. To induce extra porosity in the films, dodecane was added to the polymer casting solution. The structure, porosity, and mechanical properties of

  1. Fractography and Porosity Analysis of Cr and Cr-Mo PM Steels

    Directory of Open Access Journals (Sweden)

    Kulecki P.

    2016-09-01

    Full Text Available The aim of the study was to evaluate the effect of processing variables on the porosity and fractography of Cr and Cr-Mo PM steels. The measurements were performed on sintered steels made from commercial Höganäs pre-alloyed powders: Astaloy CrA, Astaloy CrL and Astaloy CrM with two different carbon concentrations (0.2% and 0.6% added in the form of ultra fine graphite powder grade C-UF. Following mixing in Turbula mixer for 30 minutes, green compacts were single-action pressed at 660 MPa according to PN-EN ISO 2740 standard. Sintering was carried out in a laboratory horizontal tube furnace at 1120°C and 1250°C for 60 minutes, in an atmosphere containing 5%H2 and 95%N2. After sintering, the samples were tempered at 200°C for 60 minutes in air. For porosity evaluation computer software was employed. Hitachi S-3500M SEM equipped with EDS (made by Noran was employed for fracture analysis. The steel based on Astaloy CrM pre-alloyed powder is characterized by fine pores and good mechanical properties. When sintered at 1250°C, it had area of pores approx. 7.12 μm2, ultimate tensile strength (UTS about 679 MPa and elongation about 4%. The steels were characterized by ductile/cleavage and ductile fractures.

  2. Reduce Air Infiltration in Furnaces (English/Chinese) (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-10-01

    Chinese translation of the Reduce Air Infiltration in Furnaces fact sheet. Provides suggestions on how to improve furnace energy efficiency. Fuel-fired furnaces discharge combustion products through a stack or a chimney. Hot furnace gases are less dense and more buoyant than ambient air, so they rise, creating a differential pressure between the top and the bottom of the furnace. This differential, known as thermal head, is the source of a natural draft or negative pressure in furnaces and boilers. A well-designed furnace (or boiler) is built to avoid air leakage into the furnace or leakage of flue gases from the furnace to the ambient. However, with time, most furnaces develop cracks or openings around doors, joints, and hearth seals. These openings (leaks) usually appear small compared with the overall dimensions of the furnace, so they are often ignored. The negative pressure created by the natural draft (or use of an induced-draft fan) in a furnace draws cold air through the openings (leaks) and into the furnace. The cold air becomes heated to the furnace exhaust gas temperature and then exits through the flue system, wasting valuable fuel. It might also cause excessive oxidation of metals or other materials in the furnaces. The heat loss due to cold air leakage resulting from the natural draft can be estimated if you know four major parameters: (1) The furnace or flue gas temperature; (2) The vertical distance H between the opening (leak) and the point where the exhaust gases leave the furnace and its flue system (if the leak is along a vertical surface, H will be an average value); (3) The area of the leak, in square inches; and (4) The amount of operating time the furnace spends at negative pressure. Secondary parameters that affect the amount of air leakage include these: (1) The furnace firing rate; (2) The flue gas velocity through the stack or the stack cross-section area; (3) The burner operating conditions (e.g., excess air, combustion air temperature

  3. Effect of Travel Speed and Beam Focus on Porosity in Alloy 690 Laser Welds

    Science.gov (United States)

    Tucker, Julie D.; Nolan, Terrance K.; Martin, Anthony J.; Young, George A.

    2012-12-01

    Advances in laser welding technology, including fiber optic delivery and high power density, are increasing the applicability of this joining technique. The inherent benefits of laser welding include small heat-affected zones, minimal distortion, and limited susceptibility to cracking. These advantages are of special interest to next-generation nuclear power systems where welding solute-rich alloys is expected to increase. Alloy 690 (A690) is an advanced corrosion-resistant structural material used in many replacement components and in construction of new commercial power plants. However, the application of A690 is hindered by its difficult weldability using conventional arc welding, and laser welding is a promising alternate. This work studies the effects of travel speed and beam focus on porosity formation in partial penetration, autogenous A690 laser welds. Porosity has been characterized by light optical microscopy and x-ray computed tomography to quantify its percent volume in the welds. This work describes the tradeoff between weld penetration and defect density as a function of beam defocus and travel speed. Additionally, the role of shield gas in porosity formation is discussed to provide a mitigation strategy for A690 laser welding. A process map is provided that shows the optimal combinations of travel speed and beam defocus to minimize porosity and maximize weld penetration at a laser power of 4 kW.

  4. 3D Membrane Imaging and Porosity Visualization

    KAUST Repository

    Sundaramoorthi, Ganesh

    2016-03-03

    Ultrafiltration asymmetric porous membranes were imaged by two microscopy methods, which allow 3D reconstruction: Focused Ion Beam and Serial Block Face Scanning Electron Microscopy. A new algorithm was proposed to evaluate porosity and average pore size in different layers orthogonal and parallel to the membrane surface. The 3D-reconstruction enabled additionally the visualization of pore interconnectivity in different parts of the membrane. The method was demonstrated for a block copolymer porous membrane and can be extended to other membranes with application in ultrafiltration, supports for forward osmosis, etc, offering a complete view of the transport paths in the membrane.

  5. Porosity and liquid absorption of cement paste

    DEFF Research Database (Denmark)

    Krus, M.; Hansen, Kurt Kielsgaard; Kunzel, H. M.

    1997-01-01

    be a slowing-down effect which is related to water because the absorption of organic liquids, such as hexane, is quite normal. Measurements of the porosity of hardened cement paste determined by helium pycnometry and water saturation show that water molecules can enter spaces in the microstructure which...... are not accessible to the smaller helium atoms. Considering the results of dilatation tests both before and after water and hexane saturation, it seems possible that a contraction of capillary pores due to moisture-related swelling of the cement gel leads to the non-linear water absorption over the square root...

  6. Results from a new Cocks-Ashby style porosity model

    Science.gov (United States)

    Barton, Nathan

    2017-01-01

    A new porosity evolution model is described, along with preliminary results. The formulation makes use of a Cocks-Ashby style treatment of porosity kinetics that includes rate dependent flow in the mechanics of porosity growth. The porosity model is implemented in a framework that allows for a variety of strength models to be used for the matrix material, including ones with significant changes in rate sensitivity as a function of strain rate. Results of the effect of changing strain rate sensitivity on porosity evolution are shown. The overall constitutive model update involves the coupled solution of a system of nonlinear equations.

  7. The interaction of pH, pore solution composition and solid phase composition of carbonated blast furnace slag cement paste activated with aqueous sodium monofluorophosphate

    NARCIS (Netherlands)

    Kempl, J.; Copuroglu, O.

    2015-01-01

    Blast Furnace Slag (BFS) is a waste product of industrial steel production and a common additive in the cement industry in Northern European countries. However, cementitious materials made from slag-rich cement, particularly CEM III /B, are very susceptible to carbonation. Recent investigations have

  8. Porosity of additive manufacturing parts for process monitoring

    Science.gov (United States)

    Slotwinski, J. A.; Garboczi, E. J.

    2014-02-01

    Some metal additive manufacturing processes can produce parts with internal porosity, either intentionally (with careful selection of the process parameters) or unintentionally (if the process is not well-controlled.) Material porosity is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants, since surface-breaking pores allow for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the process. We are developing an ultrasonic sensor for detecting changes in porosity in metal parts during fabrication on a metal powder bed fusion system, for use as a process monitor. This paper will describe our work to develop an ultrasonic-based sensor for monitoring part porosity during an additive build, including background theory, the development and detailed characterization of reference additive porosity samples, and a potential design for in-situ implementation.

  9. Fusion zone microstructure and porosity in electron beam welds of an α+β titanium alloy

    Science.gov (United States)

    Mohandas, T.; Banerjee, D.; Kutumba Rao, V. V.

    1999-03-01

    The effect of electron beam welding parameters on fusion zone (FZ) microstructure and porosity in a Ti -6.8 Al -3.42 Mo -1.9 Zr -0.21 Si alloy (Russian designation VT 9) has been investigated. It has been observed that the FZ grain width increased continuously with increase in heat input when the base metal was in the β heat-treated condition, while in the α+β heat-treated base metal welds, the FZ grain width increased only after a threshold energy input. The difference is attributed to both the weld thermal cycle and the pinning effect of equiaxed primary alpha on grain growth in the heat-affected zone (HAZ) of α+β heat-treated base metal. Postweld heat treatment (PWHT) in the subtransus and supertransus regions did not alter the columnar grain morphology in the FZ, possibly due to the lack of enough driving force for the formation of new grains by the breaking up of the columnar grains and grain boundary movement for grain growth. As the PWHTs were conducted in a furnace, the role of thermal gradients can be ruled out. Intragranular microstructure in the aswelded condition consisted of hexagonal martensite. The scale of the martensite laths depended on welding speed. The highest porosity was observed at intermediate welding speeds. At low speeds, a majority of pores formed at the fusion boundary, while at high speeds, occurrence of porosity was maximum at the weld center. The trends on porosity can be explained on the basis of solubility of hydrogen in titanium as a function of temperature and the influence of weld thermal cycle on nucleation, growth, and escape of hydrogen gas bubbles. The porosity at slow welding speeds is low because sufficient time exists for the nucleation, growth, and escape of hydrogen gas bubbles, while insufficient time exists for the nucleation of gas bubbles at high welding speeds. The effect of pickling of joint surface, vacuum annealing of the base metal, and successive remelting of the weld metal has also been investigated.

  10. Melting and casting of alloys in a solar furnace

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, D. (Indian Inst. of Science, Bangalore, India); Rohatgi, P.K.

    1979-01-01

    A feasibility study conducted using a small working model of a solar furnace is reported in which the melting and casting of various alloys was tested. The prototype furnace had either a spun copper or aluminum hemispherical concentrator, and was manually tracked. A later self-tracking version consisted of a paraboloidal cofiguration fabricated from a wire mesh antenna covered with aluminized polyester. The experimental results show that a simple and inexpensive solar furnace could be commercialized in the near future. (SPH)

  11. Pellet reduction properties under different blast furnace operating conditions

    OpenAIRE

    Leimalm, Ulrika

    2006-01-01

    One of the aims of modern blast furnace (BF) ironmaking is to reduce coke consumption. One way is to increase the injection of reduction agents, such as pulverized coal. An increase in pulverized coal injection rate (PCR) will affect the blast furnace process and the conditions for iron oxide reduction. Changes in PCR influence the composition of the ascending gases and the in-furnace temperature isotherms. The performed tests involve full-scale, pilot and laboratory investigations. Raw mater...

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

    Energy Technology Data Exchange (ETDEWEB)

    Stuart E. Strand

    2001-12-06

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

  13. Slag wool manufacturing from blast furnace slag

    Directory of Open Access Journals (Sweden)

    Володимир Петрович Руських

    2016-11-01

    Full Text Available Slag wool is the most expensive and valuable product of blast furnace slag processing. Slag wool is in great demand nowadays. The article highlights the factors influencing the mineral wool quality: chemical composition that determines the acidity of the module, the temperature of the molten slag and the required slag jet thickness consistency. Mineral wool is produced by blowing air or steam into a jet of molten slag. As a result of it the slag crushes into droplets stretching. The resulting wool contains 5% slag and 95% air. The quality of the obtained slag wool depends on the module acidity of the slag. The blast furnace slags of «Ilyich iron and steel works of Mariupol» and «Azovstal iron & steel works» are the main (short slags – they give short fibers. To obtain high-quality long fiber wool it is necessary to add admixtures into basic blast furnace slag to reduce its basicity. As a result of the fuel and energy rising prices and the necessity to reduce the slag wool cost it is necessary to develop a new technology with fiery-liquid slag, with the removal of iron compounds and sulphur from the melts and the introduction of corrective additives to improve the quality of slag wool. Good thermal conductivity (about 0,03 kcal/m∙h∙°C and other indicators (resistance, volume weight make it possible to use the materials from slag wool (pads, rigid and semi-rigid plates as heat and sound insulating materials

  14. Carbon Tubular Morphologies in Blast Furnace Coke

    Directory of Open Access Journals (Sweden)

    Stanislav S. Gornostayev

    2008-01-01

    Full Text Available The paper reports on the first occurrence of microscale carbon tubular morphologies (CMTs in a blast furnace (BF coke. The CMTs were probably formed as a result of the conversion of solid disordered carbon via liquid phase metal particles involving a gas phase containing a substantial amount of N2 and O2. The presence of CMTs may lie behind the generation of the smallest fraction of fines in BF exhaust dust. If the amount of CMTs present in the BF exhausts gases at any particular metallurgical site proves to be substantial, it could become a subject of environmental concern.

  15. PERFORMANCE TESTING AND ANALYSIS OF CUPOLA FURNACE

    OpenAIRE

    PROF.HEMANT R. BHAGAT-PATIL; MEGHA S. LONDHEKAR

    2013-01-01

    In today’s industrial scenario huge losses/wastage occur in the manufacturing shop floor and foundry industries. The efficiency of any foundry largely depends on the efficiency of the melting process amulti-step operation where the metal is heated, treated, alloyed, and transported into die or mold cavities to form a casting. In this paper we represents the performance testing and analysis of Cupola Furnace, and reduces the problems occurs to give the best results. Our main focus in this work...

  16. Dental Porcelain Furnaces: Test and Evaluation.

    Science.gov (United States)

    1988-01-01

    Due to the low cost of this unit it should be considered for any laboratory with a moderate to high metal-ceramic fixed partial denture work load. New...either with or without vacuum. * Slow cooling cycle: This feature allows the units to be removed slowly from the muffle following the firing cycle...DEGREES HIGH TEMPERATURE 940 DEGREES TEMPERATURE RATE 55 DEG/MIN TIME AT TEMP 0.0 MINUTES REMOVAL TIME 0.3 MINUTES FURNACE TEMP 497 DEGREES CHAMBER VACUUM

  17. Designed porosity materials in nuclear reactor components

    Science.gov (United States)

    Yacout, A. M.; Pellin, Michael J.; Stan, Marius

    2016-09-06

    A nuclear fuel pellet with a porous substrate, such as a carbon or tungsten aerogel, on which at least one layer of a fuel containing material is deposited via atomic layer deposition, and wherein the layer deposition is controlled to prevent agglomeration of defects. Further, a method of fabricating a nuclear fuel pellet, wherein the method features the steps of selecting a porous substrate, depositing at least one layer of a fuel containing material, and terminating the deposition when the desired porosity is achieved. Also provided is a nuclear reactor fuel cladding made of a porous substrate, such as silicon carbide aerogel or silicon carbide cloth, upon which layers of silicon carbide are deposited.

  18. Glass Furnace Combustion and Melting Research Facility.

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-08-01

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

  19. Arsenic immobilization of Teniente furnace dust

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-07-01

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

  20. Evaluation of concrete mechanical strength through porosity

    Directory of Open Access Journals (Sweden)

    Olivares, M.

    2004-03-01

    Full Text Available The increasing on voids or pores in any material - if the rest of characteristics remains equal -always causes a decrease in their mechanical strength since the ratio volume/resistant mass is lower Following all these fact a well known conclusion rises: there is a relationship between compacity/porosity and mechanical strengths. The purpose of this research is to establish a new possible correlation between both concrete properties with independence of the proportions, type of cement, size of grain, age, use. etc. So it can be concluded that the results of this research allow the engineer or architect in charge of a restoration or reparation to determine the compression strength of a concrete element. A first step is to determine the porosity through a rather short number of tests. Subsequently, compression strength will be obtained applying just a mathematical formula.

    El aumento de huecos o poros de cualquier material, lo mismo que en otras circunstancias, redunda siempre en una merma de sus resistencias mecánicas, al haber menor volumen-masa resistente. En consecuencia, puede deducirse, que hay una relación entre la compacidad/porosidad y las resistencias mecánicas. En el presente trabajo se estudia una posible correlación entre ambas propiedades del hormigón con independencia de su dosificación, tipo de cemento, granulometría, edad, uso, etc. Las conclusiones obtenidas en la presente investigación permiten al técnico, encargado de una restauración o rehabilitación, determinar la resistencia a compresión de un elemento de hormigón, una vez hallada, de una forma sencilla, la porosidad de una muestra no muy voluminosa, mediante la aplicación de una simple fórmula matemática.

  1. Plastic Foam Porosity Characterization by Air-Borne Ultrasound

    Science.gov (United States)

    Hoffrén, H.; Karppinen, T.; Hæggström, E.

    2006-03-01

    We continue to develop an ultrasonic burst-reflection method for estimating porosity and tortuosity of solid materials. As a first step we report on method design considerations and measurements on polyurethane foams (Sylomer® vibration dampener) with well-defined porosity. The ultrasonic method is experimentally tested by measuring 235 kHz and 600 kHz air-borne ultrasound reflection from a foam surface at two incidence angles. The reflected sound wave from different foam samples (32% - 64% porosity) was compared to a wave that had traveled from the transmitter to the detector without reflection. The ultrasonically estimated sample porosities coincided within 8% with the porosity estimates obtained by a gravimetric reference method. This parallels the uncertainty of the gravimetric method, 8%. The repeatability of the ultrasonic porosity measurements was better than 5%.

  2. Porosity Assessment for Different Diameters of Coir Lignocellulosic Fibers

    Science.gov (United States)

    da Luz, Fernanda Santos; Paciornik, Sidnei; Monteiro, Sergio Neves; da Silva, Luiz Carlos; Tommasini, Flávio James; Candido, Verônica Scarpini

    2017-10-01

    The application of natural lignocellulosic fibers (LCFs) in engineering composites has increased interest in their properties and structural characteristics. In particular, the inherent porosity of an LCF markedly affects its density and the adhesion to polymer matrices. For the first time, both open and closed porosities of a natural LCF, for different diameter ranges, were assessed. Fibers extracted from the mesocarp of the coconut fruit were investigated by nondestructive methods of density measurements and x-ray microtomography (microCT). It was found that, for all diameter ranges, the closed porosity is significantly higher than the open porosity. The total porosity increases with diameter to around 60% for coir fibers with more than 503 μm in diameter. The amount and characteristics of these open and closed porosities were revealed by t test and Weibull statistics as well as by microCT.

  3. 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.)

  4. Heat pipes and use of heat pipes in furnace exhaust

    Science.gov (United States)

    Polcyn, Adam D.

    2010-12-28

    An array of a plurality of heat pipe are mounted in spaced relationship to one another with the hot end of the heat pipes in a heated environment, e.g. the exhaust flue of a furnace, and the cold end outside the furnace. Heat conversion equipment is connected to the cold end of the heat pipes.

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

    Indian Academy of Sciences (India)

    Administrator

    Steel melting through electric arc furnace route is gaining popularity due to its many advantages, but generates a new waste, electric arc furnace slag, which is getting accumulated and land/mine filling and road construction are the only ... is a key factor, in such constructions as breakwater blocks, foundations, shoring walls, ...

  6. 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 ...

  7. Artificial neural networks in predicting current in electric arc furnaces

    Science.gov (United States)

    Panoiu, M.; Panoiu, C.; Iordan, A.; Ghiormez, L.

    2014-03-01

    The paper presents a study of the possibility of using artificial neural networks for the prediction of the current and the voltage of Electric Arc Furnaces. Multi-layer perceptron and radial based functions Artificial Neural Networks implemented in Matlab were used. The study is based on measured data items from an Electric Arc Furnace in an industrial plant in Romania.

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

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

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

  9. 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 ...

  10. THE MOVEMENT AND MIXING OF DISPERSED MATERIALS IN ROTARY FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2017-01-01

    Full Text Available This article describes motion and heat and mass transfer in the layer of dispersed material in a rotary furnace. Presents the results of a comprehensive study of these processes, including pilot studies, computer modeling and simulation, which allow to optimize the design and process parameters of rotary furnaces.

  11. Method of operating a centrifugal plasma arc furnace

    Science.gov (United States)

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

    1998-03-24

    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{sub 3}O{sub 4}. Time of exposure to oxygen is controlled so that the iron does not oxidize into Fe{sub 2}O{sub 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.

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

    Science.gov (United States)

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

    2017-02-01

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

  13. Experimental Study on the Porosity Creep Properties of Broken Limestone

    Directory of Open Access Journals (Sweden)

    Li Shun-cai

    2016-01-01

    Full Text Available In the underground engineering, the long-term stability of the surrounding rocks (especially the broken rocks containing water and the ground settlement resulted from the seepage-creep coupling above goaf have been the important research subjects concerning the deep mining. For the broken rock, its porosity is an important structural parameter determining its creep properties, and the porosity change rate is more superior to describe the creep characteristics compared with the strain change rate at a certain direction. In this paper, MTS815.02 Rock Mechanics Test System is used to carry out the creep experiments on water-saturated broken limestone, and then the time curves of porosity and of the porosity change rate are obtained. By regression, we have got the relation equation between the porosity change rate with the instant porosity and the stress level during the creep. The study indicates that when the stress retains a constant level, the relation between the porosity change rate and the instant porosity can be fitted with a cubical polynomial. The obtained creep relation equation between the porosity change rate and the instant porosity and the instant stress provides a necessary state equation for studying the coupling between the seepage and the creep of the broken rock. Furthermore, the seepage in the broken rock has been verified to satisfy the Forchheimer’s non-Darcy flow according to our previous studies, and its seepage properties, k, β and ca can all be expressed respectively as the polynomial of the porosity, so, by combining with these three state equations we have obtained the four essential state equations for solving the coupling problems of the seepage and the creep for the broken rocks.

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

    Science.gov (United States)

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

    2012-05-01

    Torrefaction and burning characteristics of bamboo, oil palm, rice husk, bagasse, and Madagascar almond were studied and compared with a high-volatile bituminous coal using a drop tube furnace to evaluate the potential of biomass consumed in blast furnaces. Torrefaction at 250 and 300°C for 1h duration was carried out. Analysis using the ash tracer method indicated that the extent of atomic carbon reduction in the biomasses was less than that of atomic hydrogen and oxygen. Torrefaction also lowered the sulfur content in bamboo and oil palm over 33%. An examination of the R-factor and burnout of the samples suggests that more volatiles were released and a higher burnout was achieved with raw and torrefied biomasses at 250°C than at 300°C; however, torrefaction at 300°C is a feasible operating condition to transform biomass into a solid fuel resembling a high-volatile bituminous coal used for blast furnaces. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Porosity effects during a severe accident

    Energy Technology Data Exchange (ETDEWEB)

    Cazares R, R. I. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Posgrado en Energia y Medio Ambiente, San Rafael Atlixco 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico); Espinosa P, G.; Vazquez R, A., E-mail: ricardo-cazares@hotmail.com [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Area de Ingenieria en Recursos Energeticos, San Rafael Atlixco 186, Col. Vicentina, 09340 Ciudad de Mexico (Mexico)

    2015-09-15

    The aim of this work is to study the behaviour of porosity effects on the temporal evolution of the distributions of hydrogen concentration and temperature profiles in a fuel assembly where a stream of steam is flowing. The analysis considers the fuel element without mitigation effects. The mass transfer phenomenon considers that the hydrogen generated diffuses in the steam by convection and diffusion. Oxidation of the cladding, rods and other components in the core constructed in zirconium base alloy by steam is a critical issue in LWR accident producing severe core damage. The oxygen consumed by the zirconium is supplied by the up flow of steam from the water pool below the uncovered core, supplemented in the case of PWR by gas recirculation from the cooler outer regions of the core to hotter zones. Fuel rod cladding oxidation is then one of the key phenomena influencing the core behavior under high-temperature accident conditions. The chemical reaction of oxidation is highly exothermic, which determines the hydrogen rate generation and the cladding brittleness and degradation. The heat transfer process in the fuel assembly is considered with a reduced order model. The Boussinesq approximation was applied in the momentum equations for multicomponent flow analysis that considers natural convection due to buoyancy forces, which is related with thermal and hydrogen concentration effects. The numerical simulation was carried out in an averaging channel that represents a core reactor with the fuel rod with its gap and cladding and cooling steam of a BWR. (Author)

  16. Casting Porosity-Free Grain Refined Magnesium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schwam, David [Case Western Reserve University

    2013-08-12

    The objective of this project was to identify the root causes for micro-porosity in magnesium alloy castings and recommend remedies that can be implemented in production. The findings confirm the key role played by utilizing optimal gating and risering practices in minimizing porosity in magnesium castings. 

  17. Tailoring the porosity of hierarchical zeolites by carbon-templating

    DEFF Research Database (Denmark)

    Zhu, Kake; Egeblad, Kresten; Christensen, Claus H.

    2008-01-01

    We report the synthesis and characterization of a series of hierarchical porous zeolite single crystal materials with a range of porosities made available by carbon-templating using differently-sized carbon particles as templates for the additional non-micropore porosity. The materials were...

  18. Porosity prediction from seismic inversion, Lavrans Field, Halten Terrace

    Energy Technology Data Exchange (ETDEWEB)

    Dolberg, David M.

    1998-12-31

    This presentation relates to porosity prediction from seismic inversion. The porosity prediction concerns the Lavrans Field of the Halten Terrace on the Norwegian continental shelf. The main themes discussed here cover seismic inversion, rock physics, statistical analysis - verification of well trends, upscaling/sculpting, and implementation. 2 refs., 6 figs.

  19. Porosity variabilities along a forest – grassland mosaic in Ibeku ...

    African Journals Online (AJOL)

    Variation existed in the porosity characteristics of pedons located on forestland and grassland. Percent coefficient of variation (CV) was greater in forest soils for both bulk density and porosity (% CV = 29.99 and 13.2) than as found in grassland soils (% CV = 2.6 and. 4.1). These results were explained by wide variations in ...

  20. 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.

  1. Resistance heated melting and holding furnaces for aluminium casting

    Energy Technology Data Exchange (ETDEWEB)

    Atkins, R.

    1989-02-01

    Resistance heated furnaces are ideal for holding and melter/holding applications in aluminium foundries. Electric resistance bale out furnaces can be fed with liquid metal and used as holding furnaces. They are also capable of melting at rates of 150/160 kg per hour at 720C. Improvements in element material have resulted in designs capable of maximum melt rates approaching that of fuel fired furnaces. A well proven design is available utilising semi-embedded elements in 2 versions to provide minimum energy consumption at lowest capital cost. A recent development is element panels produced by a new technique and using different materials which means the elements can be fully enclosed without any loss of performance. For larger aluminium pressure diecasting with substantial bulk melting facilities, insulated box furnaces have proved to be very attractive for holding metal at the diecasting machine. Electric immersion furnaces are also beginning to be used. These have the advantage of high efficiency and improved temperature control. The article concludes by discussing the implementation of energy management systems in conjunction with electric melting, and the introduction of electric ladles for keeping aluminium hot when transferring it from bulk furnaces.

  2. 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.

  3. Data Qualification Report: Calculated Porosity and Porosity-Derived Values for Lithostratigraphic Units for use on the Yucca Mountain Project

    Energy Technology Data Exchange (ETDEWEB)

    P. Sanchez

    2001-05-30

    The qualification is being completed in accordance with the Data Qualification Plan DQP-NBS-GS-000006, Rev. 00 (CRWMS M&O 2001). The purpose of this data qualification activity is to evaluate for qualification the unqualified developed input and porosity output included in Data Tracking Number (DTN) M09910POROCALC.000. The main output of the analyses documented in DTN M09910POROCALC.000 is the calculated total porosity and effective porosity for 40 Yucca Mountain Project boreholes. The porosity data are used as input to Analysis Model Report (AMR) 10040, ''Rock Properties Model'' (MDL-NBS-GS-000004, Rev. 00), Interim Change Notice [ICN] 02 (CRWMS M&O 2000b). The output from the rock properties model is used as input to numerical physical-process modeling within the context of a relationship developed in the AMR between hydraulic conductivity, bound water and zeolitic zones for use in the unsaturated zone model. In accordance with procedure AP-3.15Q, the porosity output is not used in the direct calculation of Principal Factors for post-closure safety or disruptive events. The original source for DTN M09910POROCALC.000 is a Civilian Radioactive Waste Management System (CRWMS) Management and Operating Contractor (M&O) report, ''Combined Porosity from Geophysical Logs'' (CRWMS M&O 1999a and hereafter referred to as Rael 1999). That report recalculated porosity results for both the historical boreholes covered in Nelson (1996), and the modern boreholes reported in CRWMS M&O (1996a,b). The porosity computations in Rael (1999) are based on density-porosity mathematical relationships requiring various input parameters, including bulk density, matrix density and air and/or fluid density and volumetric water content. The main output is computed total porosity and effective porosity reported on a foot-by-foot basis for each borehole, although volumetric water content is derived from neutron data as an interim output. This qualification

  4. Flow dynamics of dacite lava flow - AMS, microstructure and porosity case study

    Science.gov (United States)

    Závada, Prokop; Kusbach, Vladimír; Machek, Matěj; Staněk, Martin; Špičák, Aleš

    2017-04-01

    Pyroclastic flows derived from flow frontal collapse of highly viscous "block lavas" formed by andesite or dacite belong to the most serious volcano-related hazards for surrounding populations. The threat results from abrupt transition of lava flow from ductile flow to gravitational failure of the front, which exposes their overpressurized interior and triggers devastating pyroclastic flows. The goal of the study is to quantify the microfabrics and dynamic porosity in a lava flow to constrain the cavitation process (development and coalescence of dynamic porosity). Pleistocene dacite flow body situated on the slope of Middle Sister Volcano (OR, USA) was studied by means of field-based structural analysis, anisotropy of magnetic susceptibility (AMS), microstructural analysis and mercury injection porosimetry (MIP). The 500 m exposure of the flow is associated with a vertical feeding dyke at the beginning of the flow, 40 m upslope. The flow shows occasional layers, 5-15 cm thick, marked by evenly spaced and up to 10 cm long, lenticular to sigmoidal cracks often developed in the vicinity of the clasts/phenocrysts. These cracks frequently dip against the slope of the flow and show 15-50° difference with the layering. At the feeding dyke, highly oblate magnetic fabric shows subvertical foliations with horizontal lineations oriented parallel to the dyke walls. Middle part of the flow revealed highly prolate fabrics with subhorizontal magnetic foliations and lineations parallel to the flow direction. At the downslope limit of the flow, magnetic foliations are perpendicular to the flow direction. The dynamic porosity was studied in detail on larger sample from the central part of the flow. The sample contains three layers with different density of porosity and average crack length. All the cracks were oriented about 45° to the layer boundaries and alignment of the groundmass crystals. MIP data revealed total connected porosities between 11 and 15 %. Throat

  5. Effect of paper porosity on OCT images: Monte Carlo study

    Science.gov (United States)

    Kirillin, Mikhail Yu.; Priezzhev, Alexander V.; Myllylä, Risto

    2008-06-01

    Non-invasive measurement of paper porosity is an important problem for papermaking industry. Presently used techniques are invasive and require long time for processing the sample. In recent years optical coherence tomography (OCT) has been proved to be an effective tool for non-invasive study of optically non-uniform scattering media including paper. The aim of present work is to study the potential ability of OCT for sensing the porosity of a paper sample by means of numerical simulations. The paper sample is characterized by variation of porosity along the sample while numerical simulations allow one to consider the samples with constant porosity which is useful for evaluation of the technique abilities. The calculations were performed implementing Monte Carlo-based technique developed earlier for simulation of OCT signals from multilayer paper models. A 9-layer model of paper consisting of five fiber layers and four air layers with non-planar boundaries was considered. The porosity of the samples was varied from 30 to 80% by varying the thicknesses of the layers. The simulations were performed for model paper samples without and with optical clearing agents (benzyl alcohol, 1-pentanol, isopropanol) applied. It was shown that the simulated OCT images of model paper with various porosities significantly differ revealing the potentiality of the OCT technique for sensing the porosity. When obtaining the images of paper samples with optical clearing agents applied, the inner structure of the samples is also revealed providing additional information about the samples under study.

  6. Soil surface roughness and porosity under different tillage systems

    Science.gov (United States)

    Rodriguez-Gonzalez, J.; Saa-Requejo, A.; Gómez, J. A.; Valencia, J. L.; Zarco, P.; Tarquis, A. M.

    2012-04-01

    Both soil porosity and surface elevation can be altered by tillage operation. Even though the surface porosity is an important parameter of a tilled field, however, no practical technique for rapid and non-contact measurement of surface porosity has been developed yet. On the contrary, the surface elevation of tilled soil can be quickly determined with a laser profiler. Working under the assumption that the surface elevation of a tilled field is a complicated superposition of the soil terrain profile at a larger-scale and the roughness at a fine-scale, this study included three aspects: (i) to establish an index (Roughness Index, RI) at a fine-scale to associate the surface roughness with porosity; (ii) to examine the correlation between surface porosity and the proposed RI by three types of tillage treatment in the field; and (iii) to check the scaling/multiscaling behavior among different grid sizes of calculating RI on predicting surface porosity. Consequently, the statistical results from each tilled plot show a strong correlation between the surface porosity and the defined RI in an early stage (ca. 2 days) after tillage. Acknowledgements Funding provided by CEIGRAM (Research Centre for the Management of Agricultural and Environmental Risks)and Spanish Ministerio de Ciencia e Innovación (MICINN) through project AGL2010-21501/AGR is greatly appreciated.

  7. Saturated hydraulic conductivity and porosity within macroaggregates modified by tillage

    Energy Technology Data Exchange (ETDEWEB)

    Park, E.J.; Smucker, A.J.M. (MSU)

    2010-07-20

    Greater knowledge of intraaggregate porosity modifications by tillage conveys new information for identifying additional hydrologic, ion retention, and aggregate stability responses to specific management practices. Macroaggregates, 2 to 4, 4 to 6.3, and 6.3 to 9.5 mm across, were separated into multiple concentric layers and their porosities were determined. Saturated hydraulic conductivity (K{sub s}) of multiple aggregate fractions from two soil types subjected to conventional tillage (CT), no tillage (NT), and native forest (NF) soils were measured individually to identify the effects of tillage on aggregate structure, porosity, and K{sub s}. Intraaggregate porosities were the highest in NF aggregates. Greater porosities were identified in exterior layers of soil aggregates from all treatments. Lowest intraaggregate porosities were observed in the central regions of CT aggregates. Soil aggregates, 6.3 to 9.5 mm across, had the greatest total porosities, averaging 37.5% for both soil types. Long-term CT reduced intraaggregate porosities and K, within macroaggregates, of the same size fraction, from both the Hoytville silty clay loam and Wooster silt loam soil types. Values for K, of NF aggregates, 5.0 x 10{sup -5} cm s{sup -1}, were reduced 50-fold by long-term CT treatments of the Hoytville series. The K, values through Wooster aggregates from NF, 16.0 x 10{sup -5} cm s{sup -1}, were reduced 80-fold by long-term CT treatments. The K{sub s} values through NF and NT aggregates were positively correlated with their intraaggregate porosities (R{sup 2} = 0.84 for NF and R{sup 2} = 0.45 for NT at P < 0.005). Additional studies are needed to identify rates at which pore geometries within macroaggregates are degraded by CT or improved by NT.

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

    Data.gov (United States)

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

  9. Innovation in electric arc furnaces scientific basis for selection

    CERN Document Server

    Toulouevski, Yuri N

    2013-01-01

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

  10. Silica crown refractory corrosion in glass melting furnaces

    National Research Council Canada - National Science Library

    Balandis A; Nizeviciene D

    2011-01-01

    ... of glass furnaces, when the rate of corrosion of crowns were about 2 times greater. The change of these parameters, the chemical composition and formation of the microcracks in the used silica refractories material were studied...

  11. Alloying and Casting Furnace for Shape Memory Alloys Project

    Data.gov (United States)

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

  12. Design considerations for solar furnace focal zone apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Sievers, R.H. Jr.; Knasel, T.M.; McDonnell, M.; Gordon, B.; Woods, S.; Malinowski, R.

    1981-01-01

    Science Applications, Inc. has used the principal solar furnaces in conjunction with its study of the effect of high thermal fluxes and fluences on soil surfaces for the Defense Nuclear Agency. Apparatus to perform these tests has evolved from tests on the furnaces at the White Sands Missile Range, Georgia Institute of Technology in Atlanta; Centre National de Recherche Scientifique in Font Romeu, France; and Kirtland AFB, NM over the past 6 years. The apparatus is still evolving as it is adapted to additional furnaces and to obtain a greater variety of data. The evolution of the apparatus is traced to illustrate the interaction of experiment objectives; furnace capabilities, configuration, and support; apparatus design; data collection; and response to lessons learned.

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

    Data.gov (United States)

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

  14. DEVELOPMENT OF A FURNACE TO FABRICATE SILICON SOLAR CELLS

    Directory of Open Access Journals (Sweden)

    Sérgio Boscato Garcia

    2012-06-01

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

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

    Directory of Open Access Journals (Sweden)

    A. Haxhiaj

    2012-10-01

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

  16. The Flexibility of Pusher Furnace Grate

    Directory of Open Access Journals (Sweden)

    Słowik J.A.

    2016-12-01

    Full Text Available The lifetime of guide grates in pusher furnaces for heat treatment could be increased by raising the flexibility of their structure through, for example, the replacement of straight ribs, parallel to the direction of grate movement, with more flexible segments. The deformability of grates with flexible segments arranged in two orientations, i.e. crosswise (perpendicular to the direction of compression and lengthwise (parallel to the direction of compression, was examined. The compression process was simulated using SolidWorks Simulation program. Relevant regression equations were also derived describing the dependence of force inducing the grate deformation by 0.25 mm ‒ modulus of grate elasticity ‒ on the number of flexible segments in established orientations. These calculations were made in Statistica and Scilab programs. It has been demonstrated that, with the same number of segments, the crosswise orientation of flexible segments increases the grate structure flexibility in a more efficient way than the lengthwise orientation. It has also been proved that a crucial effect on the grate flexibility has only the quantity and orientation of segments (crosswise / lengthwise, while the exact position of segments changes the grate flexibility by less than 1%.

  17. Recovery of Porosity and Permeability for High Plasticity Clays

    DEFF Research Database (Denmark)

    Krogsbøll, Anette; Foged, Niels Nielsen

    Clays, which have been loaded to a high stress level, will under certain conditions keep low porosity and permeability due to the high degree of compression. In some situations it seems that porosity and permeability will recover to a very high extent when the clay is unloaded. This seems...... to be the case for high plasticity clays that are uncemented, and with a high content of clay minerals, especially smectite. Oedometer tests on samples from the Paleogene period show that 80% or more of the compaction will recover when unloaded, and if unloaded to a stress lower than in situ stress level...... the clay will expand to an even higher porosity....

  18. A Permeability-Porosity Relationship for Surface Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Weir, G.J.; White, S.P.

    1995-01-01

    The changes to porosity and permeability resulting from surface deposition and early dissolution in an initial rhombohedral array of uniform spheres are calculated. Very rapid decreases of permeability result from early deposition, with 48% reduction predicted in permeability from 8% reduction in porosity. After deposition has caused about a 1% increase in the radii of the spherical array, relative permeability reductions vary approximately as the square of relative changes in porosity. These theoretical results are matched with experimental data of Ioti et al. and shown to be satisfactory in some cases, but for others, a more complex model of the porous medium is needed.

  19. Investigation of radiative heat transfer in fixed bed biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    T. Klason; X.S. Bai; M. Bahador; T.K. Nilsson; B. Sunden [Lund Institute of Technology, Lund (Sweden). Division of Fluid Mechanics

    2008-08-15

    This paper presents an investigation of the radiative heat transfer process in two fixed bed furnaces firing biomass fuels and the performance of several widely used models for calculation of radiative heat transfer in the free-room of fixed bed furnaces. The effective mean grey gas absorption coefficients are calculated using an optimised version of the exponential wide band model (EWBM) based on an optical mean beam length. Fly-ash and char particles are taken into account using Mie scattering. In the investigated updraft small-scale fixed bed furnace radiative transfer carries heat from the bed to the free-room, whereas in the cross-current bed large-scale industry furnace, radiative transfer brings heat from the hot zones in the free-room to the drying zone of the bed. Not all the investigated models can predict these heat transfer trends, and the sensitivity of results to model parameters is fairly different in the two furnaces. In the small-scale furnace, the gas absorption coefficient predicted by using different optical lengths has great impact on the predicted temperature field. In the large-scale furnaces, the predicted temperature field is less sensitive to the optical length. In both furnaces, with the same radiative properties, the low-computational-cost P1 model predicts a temperature field in the free-room similar to that by the more time consuming SLW model. In general, the radiative heat transfer rates to the fuel bed are not very sensitive to the radiative properties, but they are sensitive to the different radiative heat transfer models. For a realistic prediction of the radiative heat transfer rate to the fuel bed or to the walls, more computationally demanding models such as the FGG or SLW models should be used. 37 refs., 7 figs., 2 tabs.

  20. Mathematical model and software for control of commissioning blast furnace

    Science.gov (United States)

    Spirin, N. A.; Onorin, O. P.; Shchipanov, K. A.; Lavrov, V. V.

    2016-09-01

    Blowing-in is a starting period of blast furnace operation after construction or major repair. The current approximation methods of blowing-in burden analysis are based on blowing-in practice of previously commissioned blast furnaces. This area is theoretically underexplored; there are no common scientifically based methods for selection of the burden composition and blast parameters. The purpose of this paper is development and scientific substantiation of the methods for selection of the burden composition and blast parameters in the blast furnace during the blowing-in period. Research methods are based on physical regularities of main processes running in the blast furnace, system analysis, and application of modern principles for development and construction of mathematical models, algorithms and software designed for automated control of complex production processes in metallurgy. As consequence of the research made by the authors the following results have been achieved: 1. A set of mathematical models for analysis of burden arrangement throughout the height of the blast furnace and for selection of optimal blast and gas dynamic parameters has been developed. 2. General principles for selection of the blowing-in burden composition and blast and gas dynamic parameters have been set up. 3. The software for the engineering and process staff of the blast furnace has been developed and introduced in the industry.

  1. Similarity of Ferrosilicon Submerged Arc Furnaces With Different Geometrical Parameters

    Directory of Open Access Journals (Sweden)

    Machulec B.

    2017-12-01

    Full Text Available In order to determine reasons of unsatisfactory production output regarding one of the 12 MVA furnaces, a comparative analysis with a furnace of higher power that showed a markedly better production output was performed. For comparison of ferrosilicon furnaces with different geometrical parameters and transformer powers, the theory of physical similarity was applied. Geometrical, electrical and thermal parameters of the reaction zones are included in the comparative analysis. For furnaces with different geometrical parameters, it is important to ensure the same temperature conditions of the reaction zones. Due to diverse mechanisms of heat generation, different criteria for determination of thermal and electrical similarity for the upper and lower reaction zones were assumed contrary to other publications. The parameter c3 (Westly was assumed the similarity criterion for the upper furnace zones where heat is generated as a result of resistive heating while the parameter J1 (Jaccard was assumed the similarity criterion for the lower furnace zones where heat is generated due to arc radiation.

  2. CO2 Laser Glazing Treatment of a Veneering Porcelain: Effects on Porosity, Translucency, and Mechanical Properties.

    Science.gov (United States)

    Sgura, R; dos Reis, M C; Salvadori, M C; Hernandes, A C; Cesar, P F; Medeiros, I S

    2015-01-01

    This work tested CO2 laser as a glazing agent and investigated the effects of irradiation on the porosity, translucency, and mechanical properties of veneering porcelain. Sixty discs (diameter 3.5 × 2.0 mm) of veneering porcelain for Y-TZP frameworks (VM9, VITA Zahnfabrik) were sintered and had one of their faces mirror polished. The specimens were divided into six groups (n=10/group) according to surface treatment, as follows: no treatment-control; auto-glaze in furnace following manufacturer's instructions (G); and CO2 laser (45 or 50 W/cm(2)) applied for four or five minutes (L45/4, L45/5, L50/4, L50/5). Optical microscopy (Shimadzu, 100×) was conducted and the images were analyzed with Image J software for the determination of the following porosity parameters: area fraction, average size, and Feret diameter. The translucency parameter studied was masking ability, determined by color difference (ΔE) over black and white backgrounds (CM3370d, Konica Minolta). Microhardness and fracture toughness (indentation fracture) were measured with a Vickers indenter (HMV, Shimadzu). Contact atomic force microscopy (AFM) (50 × 50 μm(2), Nanoscope IIIA, Veeco) was performed at the center of one sample from each group, except in the case of L45/5. With regard to porosity and translucency parameters, auto-glazed and laser-irradiated specimens presented statistical similarity. The area fraction of the surface pores ranged between 2.4% and 5.4% for irradiated specimens. Group L50/5 presented higher microhardness when compared to the G group. The higher (1.1) and lower (0.8) values for fracture toughness (MPa.m(1/2)) were found in laser-irradiated groups (L50/4 and L45/4, respectively). AFM performed after laser treatment revealed changes in porcelain surface profile at a submicrometric scale, with the presence of elongated peaks and deep valleys.

  3. 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.

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

    National Research Council Canada - National Science Library

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

    2012-01-01

    The paper gives a common outline about the known recycling techniques from electric arc furnace dusts and describes an investigation of a pyrometallurgical process for the recovery of zinc and iron...

  5. 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.

  6. Porosity and Mechanical Strength of an Autoclaved Clayey Cellular Concrete

    Directory of Open Access Journals (Sweden)

    P. O. Guglielmi

    2010-01-01

    Full Text Available This paper investigates the porosity and the mechanical strength of an Autoclaved Clayey Cellular Concrete (ACCC with the binder produced with 75 wt% kaolinite clay and 25 wt% Portland cement. Aluminum powder was used as foaming agent, from 0.2 wt% to 0.8 wt%, producing specimens with different porosities. The results show that the specimens with higher content of aluminum presented pore coalescence, which can explain the lower porosity of these samples. The porosities obtained with the aluminum contents used in the study were high (approximately 80%, what accounts for the low mechanical strength of the investigated cellular concretes (maximum of 0.62 MPa. Nevertheless, comparing the results obtained in this study to the ones for low temperature clayey aerated concrete with similar compositions, it can be observed that autoclaving is effective for increasing the material mechanical strength.

  7. Porosity-dependent fractal nature of the porous silicon surface

    Energy Technology Data Exchange (ETDEWEB)

    Rahmani, N.; Dariani, R. S., E-mail: dariani@alzahra.ac.ir [Department of Physics, Alzahra University, Tehran, 1993893973 (Iran, Islamic Republic of)

    2015-07-15

    Porous silicon films with porosity ranging from 42% to 77% were fabricated by electrochemical anodization under different current density. We used atomic force microscopy and dynamic scaling theory for deriving the surface roughness profile and processing the topography of the porous silicon layers, respectively. We first compared the topography of bare silicon surface with porous silicon and then studied the effect of the porosity of porous silicon films on their scaling behavior by using their self-affinity nature. Our work demonstrated that silicon compared to the porous silicon films has the highest Hurst parameter, indicating that the formation of porous layer due to the anodization etching of silicon surface leads to an increase of its roughness. Fractal analysis revealed that the evolution of the nanocrystallites’ fractal dimension along with porosity. Also, we found that both interface width and Hurst parameter are affected by the increase of porosity.

  8. Permeability and porosity models of bi-fractal porous media

    Science.gov (United States)

    Tan, Xiao-Hua; Kui, Ming-Qing; Li, Xiao-Ping; Mao, Zheng-Lin; Xiao, Heng

    2017-11-01

    In previous studies, it is found that the frame and pore in porous media both possess the fractal geometric character. So the permeability and porosity models of bi-fractal porous media are derived based on the assumption that a porous media consists of fractal solid clusters and capillary bundles. The expressions of presented models are constituted by the fractal parameters of solid cluster and those of capillary bundle. Good agreement between model predictions and experimental data is obtained. This verifies the validity of the permeability and porosity models for bi-fractal porous media. The sensitive parameters that influence the permeability and porosity are specified, and their effects on the relationship between permeability and porosity are discussed.

  9. Influence of Chemical Composition on Porosity in Aluminium Alloys

    Directory of Open Access Journals (Sweden)

    Kucharčík L.

    2014-06-01

    Full Text Available Porosity is one of the major defects in aluminum castings, which results is a decrease of a mechanical properties. Porosity in aluminum alloys is caused by solidification shrinkage and gas segregation. The final amount of porosity in aluminium castings is mostly influenced by several factors, as amount of hydrogen in molten aluminium alloy, cooling rate, melt temperature, mold material, or solidification interval. This article deals with effect of chemical composition on porosity in Al-Si aluminum alloys. For experiment was used Pure aluminum and four alloys: AlSi6Cu4, AlSi7Mg0, 3, AlSi9Cu1, AlSi10MgCu1.

  10. Effects of Porosity and Thermal Treatment on Hydration of Mushrooms

    OpenAIRE

    Paudel, Ekaraj; Boom, R.M.; Sman, van der, R.G.M.

    2016-01-01

    In this study, hydration of mushroom as a porous food material has been studied considering their biphasic character. It consists of a solid phase that consists of intertwined hyphae and having cell walls with a swellable polymeric matrix and a pore phase made up by the space in between the hyphae. We have investigated the hydration of mushrooms as a function of initial porosity and thermal treatment. Variation in porosity is induced by the natural variation in the growth of mushroom. Porosit...

  11. The Albedo of Pervious Cement Concrete Linearly Decreases with Porosity

    OpenAIRE

    Rui Zhang; Guosheng Jiang; Jia Liang

    2015-01-01

    Pervious pavements have been advocated as a potential countermeasure to the urban heat island effect. To understand if pervious pavements stay cooler than conventional pavements, the albedo of the pervious concrete must be understood. This study measured the albedo of pervious concrete with different porosity. Four Portland cement concrete mixes were casted, using designed amounts of sand to vary the porosity of the pervious concrete samples. The samples were sliced and the spectral reflectan...

  12. Modulus Dependence on Large Scale Porosity of Powder Metallurgy Steel

    Science.gov (United States)

    Allison, P. G.; Horstemeyer, M. F.; Brown, H. R.

    2012-07-01

    This article compares the existing theoretical expressions for the porosity dependence on elastic constants to experimental data for a commercially available material, FC-0205 powder metallurgy (PM) steel. The modulus of compression, tension, effective torsion, and ultrasound-based data at varying porosity levels are plotted graphically against the theoretical expressions. An equation by McAdam ( J. Iron Steel Inst. Lond., 1950, 168, p 346) was able to most accurately predict the experimental data with the adjustment of only one material constant.

  13. Porosity Variation in Cenozoic and Upper Chalk from the Ontong Java Pleateau

    DEFF Research Database (Denmark)

    Borre, Mai Kirstine

    1997-01-01

    Porosity was obtained from matrix- and intraparticle porosity assessed from image analysis of backscattered electron micrographs of 3000x and 300x magnification. Comparing porosity assessed from image analysis with porosity measured by index properties, it was seen that image analysis data at 3000x...... magnification overestimates the dominating phase where images are resolved well, because of transparency in the upper few microns of the sample. Thus image analysis porosity in the upper ooze interval (porosities more than 65%) show a good correspondence, because of the combined effect of porosity being...... the domination phase and insufficient resolution leading to porosity underestimation. In chalk samples (porosities around 50% or more) the lowest estimate of image analysis porosity corresponded because of the transparency, whereas in limestone samples (porosities less than 25%) highest image porosity estimate...

  14. Porosity Measurements and Analysis for Metal Additive Manufacturing Process Control.

    Science.gov (United States)

    Slotwinski, John A; Garboczi, Edward J; Hebenstreit, Keith M

    2014-01-01

    Additive manufacturing techniques can produce complex, high-value metal parts, with potential applications as critical metal components such as those found in aerospace engines and as customized biomedical implants. Material porosity in these parts is undesirable for aerospace parts - since porosity could lead to premature failure - and desirable for some biomedical implants - since surface-breaking pores allows for better integration with biological tissue. Changes in a part's porosity during an additive manufacturing build may also be an indication of an undesired change in the build process. Here, we present efforts to develop an ultrasonic sensor for monitoring changes in the porosity in metal parts during fabrication on a metal powder bed fusion system. The development of well-characterized reference samples, measurements of the porosity of these samples with multiple techniques, and correlation of ultrasonic measurements with the degree of porosity are presented. A proposed sensor design, measurement strategy, and future experimental plans on a metal powder bed fusion system are also presented.

  15. Numerical study of porosity in titanium dental castings.

    Science.gov (United States)

    Wu, M; Sahm, P R; Augthun, M; Spiekermann, H; Schädlich-Stubenrauch, J

    1999-09-01

    A commercial software package, MAGMASOFT (MAGMA Giessereitechnologie GmbH, Aachen, Germany), was used to study shrinkage and gas porosity in titanium dental castings. A geometrical model for two simplified tooth crowns connected by a connector bar was created. Both mold filling and solidification of this casting model were numerically simulated. Shrinkage porosity was quantitatively predicted by means of a built-in feeding criterion. The risk of gas pore formation was investigated using the numerical filling and solidification results. The results of the numerical simulations were compared with experiments, which were carried out on a centrifugal casting machine with an investment block mold. The block mold was made of SiO2 based slurry with a 1 mm thick Zr2 face coat to reduce metal-mold reactions. Both melting and casting were carried out under protective argon (40 kPa). The finished castings were sectioned and the shrinkage porosity determined. The experimentally determined shrinkage porosity coincided with the predicted numerical simulation results. No apparent gas porosity was found in these model castings. Several running and gating systems for the above model casting were numerically simulated. An optimized running and gating system design was then experimentally cast, which resulted in porosity-free castings. Copyright 1999 Kluwer Academic Publishers

  16. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D., E-mail: david.chartier@cea.fr [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Muzeau, B. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Stefan, L. [AREVA NC/D& S - France/Technical Department, 1 place Jean Millier 92084 Paris La Défense (France); Sanchez-Canet, J. [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Monguillon, C. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2017-03-15

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  17. Porosity and packing of Holocene river, dune, and beach sands

    Energy Technology Data Exchange (ETDEWEB)

    Atkins, J.E. (Conoco, Inc., Oklahoma City, OK (United States)); McBride, E.F. (Univ. of Texas, Austin (United States))

    1991-03-01

    The porosity and packing of 174 samples of well-sorted surficial and shallowly buried (to 17 m), unconsolidated Holocene sands were determined by point counting the upper surface of thin sections of epoxy-impregnated samples in reflected light. Average depositional porosity for 124 surficial beach sands, river point-bar and braid-bar sands, and eolian dune sands is between 40% and 58%. Beach sands exhibit an average packing value (contact index = CI) of 0.79, river sands an average IC of 0.91, and eolian dune sands an average CI of 1.02. Packing gets tighter with depth, but the authors found no decrease in porosity with depth for river and beach sands buried to 17 m. Thus, packing is more sensitive to small changes in fabric than is porosity. Beach sands typically contain 5.5% oversized pores (OSP), river sands 3.8% OSP, and eolian dune sands 4.0% OSP. Most OSP are packing defects rather than dissolution pores, although trapped air bubbles are common in some beach sands. OSP decrease linearly with depth to 17 m, our deepest sample. Extrapolation of our data indicates that they will be destroyed at a depth less than 100 m. Significant differences in porosity, oversized-pore, and packing values exist between most point-bar and braid-bar deposits and between two heavily sampled point bars, but no significant differences in these values exist when braid-bar sands are compared to other braid-bar sands. Sands form different beaches have significant differences in porosity, oversized pores, and packing. The average porosity is 46% for eolian ripple strata, 50% for grain-fall strata, and 51% for grain-flow strata. Ripple strata are tighter packed than grain-fall and grain-flow strata.

  18. Model reduction for experimental thermal characterization of a holding furnace

    Science.gov (United States)

    Loussouarn, Thomas; Maillet, Denis; Remy, Benjamin; Dan, Diane

    2017-09-01

    Vacuum holding induction furnaces are used for the manufacturing of turbine blades by loss wax foundry process. The control of solidification parameters is a key factor for the manufacturing of these parts. The definition of the structure of a reduced heat transfer model with experimental identification through an estimation of its parameters is required here. Internal sensors outputs, together with this model, can be used for assessing the thermal state of the furnace through an inverse approach, for a better control. Here, an axisymmetric furnace and its load have been numerically modelled using FlexPDE, a finite elements code. The internal induction heat source as well as the transient radiative transfer inside the furnace are calculated through this detailed model. A reduced lumped body model has been constructed to represent the numerical furnace. The model reduction and the estimation of the parameters of the lumped body have been made using a Levenberg-Marquardt least squares minimization algorithm, using two synthetic temperature signals with a further validation test.

  19. Effect of Temperature on the Properties and Microstructures of Carbon Refractories for Blast Furnace

    Science.gov (United States)

    Chen, Xilai; Li, Yawei; Li, Yuanbing; Jin, Shengli; Zhao, Lei; Ge, Shan

    2009-07-01

    The effects of temperature on phase composition, microstructure, and properties of silicon-containing blast furnace (BF) carbon refractories after firing in coke breeze packing at 1000 °C to 1600 °C were studied with the aid of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray, mercury porosimetry, and a laser thermal conductivity meter. The results showed that silicon played a dominant role in the evolution of phase, microstructure, and properties. The amount of SiC whiskers increased with temperature. The phase in the outer part of the specimen was cristobalite balls, and its content decreased and β-SiC whisker increased in the inner part of the specimen. The phase and microstructure development with firing temperature influenced the properties. The bulk density, strength, and <1- μm micropore volume of open pores were highest, whereas the apparent and total porosity, mean pore size, and thermal conductivity were lowest for specimens fired at 1400 °C. Moreover, the thermal conductivity was affected by pore structure and phases formed after firing.

  20. Testing Mercury Porosimetry with 3D Printed Porosity Models

    Science.gov (United States)

    Hasiuk, F.; Ewing, R. P.; Hu, Q.

    2014-12-01

    Mercury intrusion porosimetry is one of the most widely used techniques to study the porous nature of a geological and man-made materials. In the geosciences, it is commonly used to describe petroleum reservoir and seal rocks as well as to grade aggregates for the design of asphalt and portland cement concretes. It's wide utility stems from its ability to characterize a wide range of pore throat sizes (from nanometers to around a millimeter). The fundamental physical model underlying mercury intrusion porosimetry, the Washburn Equation, is based on the assumption that rock porosity can be described as a bundle of cylindrical tubes. 3D printing technology, also known as rapid prototyping, allows the construction of intricate and accurate models, exactly what is required to build models of rock porosity. We evaluate the applicability of the Washburn Equation by comparing properties (like porosity, pore and pore throat size distribution, and surface area) computed on digital porosity models (built from CT data, CAD designs, or periodic geometries) to properties measured via mercury intrusion porosimetry on 3D printed versions of the same digital porosity models.

  1. The steady aerodynamics of aerofoils with porosity gradients

    Science.gov (United States)

    Hajian, Rozhin; Jaworski, Justin W.

    2017-09-01

    This theoretical study determines the aerodynamic loads on an aerofoil with a prescribed porosity distribution in a steady incompressible flow. A Darcy porosity condition on the aerofoil surface furnishes a Fredholm integral equation for the pressure distribution, which is solved exactly and generally as a Riemann-Hilbert problem provided that the porosity distribution is Hölder-continuous. The Hölder condition includes as a subset any continuously differentiable porosity distributions that may be of practical interest. This formal restriction on the analysis is examined by a class of differentiable porosity distributions that approach a piecewise, discontinuous function in a certain parametric limit. The Hölder-continuous solution is verified in this limit against analytical results for partially porous aerofoils in the literature. Finally, a comparison made between the new theoretical predictions and experimental measurements of SD7003 aerofoils presented in the literature. Results from this analysis may be integrated into a theoretical framework to optimize turbulence noise suppression with minimal impact to aerodynamic performance.

  2. Dual integral porosity shallow water model for urban flood modelling

    Science.gov (United States)

    Guinot, Vincent; Sanders, Brett F.; Schubert, Jochen E.

    2017-05-01

    With CPU times 2 to 3 orders of magnitude smaller than classical shallow water-based models, the shallow water equations with porosity are a promising tool for large-scale modelling of urban floods. In this paper, a new model formulation called the Dual Integral Porosity (DIP) model is presented and examined analytically and computationally with a series of benchmark tests. The DIP model is established from an integral mass and momentum balance whereby both porosity and flow variables are defined separately for control volumes and boundaries, and a closure scheme is introduced to link control volume- and boundary-based flow variables. Previously developed Integral Porosity (IP) models were limited to a single set of flow variables. A new transient momentum dissipation model is also introduced to account for the effects of sub-grid scale wave action on porosity model solutions, effects which are validated by fine-grid solutions of the classical shallow-water equations and shown to be important for achieving similarity in dam-break solutions. One-dimensional numerical test cases show that the proposed DIP model outperforms the IP model, with significantly improved wave propagation speeds, water depths and discharge calculations. A two-dimensional field scale test case shows that the DIP model performs better than the IP model in mapping the floods extent and is slightly better in reproducing the anisotropy of the flow field when momentum dissipation parameters are calibrated.

  3. Porosity Distribution in Composite Structures with Infrared Thermography

    Directory of Open Access Journals (Sweden)

    Cinzia Toscano

    2013-01-01

    Full Text Available Composite structures are increasingly used in the transport industry especially in the aeronautical sector thanks to their favorable strength-to-weight ratio with respect to metals. However, this is true if the final part is defects free and complies with quality requirements. A main weakness in composites is porosity, which is likely to be introduced during manufacturing processes and which may knock down the material characteristics affecting its performance in service. Porosity plays a key role in sandwich structures, which involve novel metal foams as core, since the foam performance strongly depends on size and distribution of pores. The determination of porosity is mostly attained by destructive methods, which supply only a general indication linked to the production part number. Conversely, composites may entail local significant variation of porosity, which may be discovered only with effective nondestructive techniques. The attention of the present work is focused on the possibility to use infrared thermography to get information about the amount and distribution of porosity. In particular, two techniques: flash thermography and lock-in thermography are used to comply with requirements of both monolithic composites and metal foams.

  4. The steady aerodynamics of aerofoils with porosity gradients.

    Science.gov (United States)

    Hajian, Rozhin; Jaworski, Justin W

    2017-09-01

    This theoretical study determines the aerodynamic loads on an aerofoil with a prescribed porosity distribution in a steady incompressible flow. A Darcy porosity condition on the aerofoil surface furnishes a Fredholm integral equation for the pressure distribution, which is solved exactly and generally as a Riemann-Hilbert problem provided that the porosity distribution is Hölder-continuous. The Hölder condition includes as a subset any continuously differentiable porosity distributions that may be of practical interest. This formal restriction on the analysis is examined by a class of differentiable porosity distributions that approach a piecewise, discontinuous function in a certain parametric limit. The Hölder-continuous solution is verified in this limit against analytical results for partially porous aerofoils in the literature. Finally, a comparison made between the new theoretical predictions and experimental measurements of SD7003 aerofoils presented in the literature. Results from this analysis may be integrated into a theoretical framework to optimize turbulence noise suppression with minimal impact to aerodynamic performance.

  5. 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.

  6. Gas dynamics of reactive gases in swirling-type furnace

    Science.gov (United States)

    Akhmetshina, A. I.; Pavlov, G. I.; Sabirzyanov, A. N.; Tikhonov, O. A.

    2017-09-01

    It is known from the literature that for the complete reaction of two gases (fuel and oxidizer), it is necessary to fulfill three basic conditions: the stoichiometric ratio of reactive gases, qualitative mixing and ensuring the cooling of combustion products without "quenching". Of the above-stated conditions it is more difficult to organize a qualitative mixture formation. This physical process requires additional expenditure of energy flow. In this work we present the results of experimental and theoretical studies of the gas dynamics of a reactive gas mixture in a swirling-type furnace. The design scheme of the furnace includes two reaction zones for combustible components: the first zone is the zone of generation of combustible gases which composition is constant; the second zone of the furnace - zone of a homogeneous combustion reaction.

  7. A feasibility assessment of cogeneration from a regenerative glass furnace

    Energy Technology Data Exchange (ETDEWEB)

    Hnat, J.G.; Coles, W.F.

    1985-07-01

    In typical oil/gas-fired regenerative glass furnaces, approximately one-third of the total thermal input is exhausted out the stack at temperatures in the range of 700-1000/sup 0/F. The results of a site specific feasibility assessment of cogeneration from the stack gas waste heat of a regenerative glass furnace is summarized. Three different cogeneration concepts were evaluated for heat recovery. They included: a) a conventional steam Rankine cycle, b) an organic Rankine cycle, and c) a pressurized Brayton cycle. The performance and economics of the three cogeneration heat recovery systems are compared for a range of flue gas temperatures and flow rates which encompass expected operating conditions for a nominal furnace campaign period.

  8. DUCT RETROFIT STRATEGY TO COMPLEMENT A MODULATING FURNACE.

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS,J.W.

    2002-10-02

    Some recent work (Walker 2001, Andrews 2002) has indicated that installing a modulating furnace in a conventional duct system may, in many cases, result in a significant degradation in thermal distribution efficiency. The fundamental mechanism was pointed out nearly two decades ago (Andrews and Krajewski 1985). The problem occurs in duct systems that are less-than-perfectly insulated (e.g., R-4 duct wrap) and are located outside the conditioned space. It stems from the fact that when the airflow rate is reduced, as it will be when the modulating furnace reduces its heat output rate, the supply air will have a longer residence time in the ducts and will therefore lose a greater percentage of its heat by conduction than it did at the higher airflow rate. The impact of duct leakage, on the other hand, is not expected to change very much under furnace modulation. The pressures in the duct system will be reduced when the airflow rate is reduced, thus reducing the leakage per unit time. This is balanced by the fact that the operating time will increase in order to meet the same heating load as with the conventional furnace operating at higher output and airflow rates. The balance would be exact if the exponent in the pressure vs. airflow equation were the same as that in the pressure vs. duct leakage equation. Since the pressure-airflow exponent is usually {approx}0.5 and the pressure-leakage exponent is usually {approx}0.6, the leakage loss as a fraction of the load should be slightly lower for the modulating furnace. The difference, however, is expected to be small, determined as it is by a function with an exponent equal to the difference between the above two exponents, or {approx}0.1. The negative impact of increased thermal conduction losses from the duct system may be partially offset by improved efficiency of the modulating furnace itself. Also, the modulating furnace will cycle on and off less often than a single-capacity model, and this may add a small amount

  9. 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.

  10. Secondary Aluminum Melting Research in a Laboratory Scale Reverberatory Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Clark, J.A., III

    2003-01-01

    The Albany Research Center (ARC), U.S. Department of Energy, has developed a 175-pound capacity, natural gas, direct-fired reverberatory furnace. The high temperature reactions present during the aluminum remelt process are being investigated. Preventing dross formation has been the key aim to date. Reducing losses to dross by 25-50% will potentially lead to an annual energy savings of over 75 trillion BTU's by the year 2020. Schematics and operation characteristics of the ARC Laboratory Scale Reverberatory Furnace (LSRF) will be presented. Potential gas-solid, gas-liquid, and liquid-solid interactions between the hot combustion gases, aluminum, and refractories will be discussed.

  11. Modeling the Gas-Solid Flow in Calcining Furnace

    Directory of Open Access Journals (Sweden)

    Haiyan Luo

    2011-03-01

    Full Text Available Gas-solid two-phase flow in calcining furnace is investigated in this paper. The turbulent fluid phase is calculated using the RNG k-e two-equation model in the Eulerain framework while the solid phase being handled via the particle stochastic trajectory model is calculated in the Lagrangian framework. Flow pattern characteristics of the fluid phase and the particle trajectories of the solid phase were predicted subject to a range of flow conditions and different particle sizes. The computed results provided useful information in the preview of kinetics regulation of the gas-solid two-phase in calcining furnace.

  12. Processing and characterization of high porosity aerogel films

    Energy Technology Data Exchange (ETDEWEB)

    Hrubesh, L.W.; Poco, J.F.

    1994-11-22

    Aerogels are highly porous solids having unique morphology among materials because both the pores and particles making up the material have sizes less than wavelengths of visible light. Such a unique morphology modifies the normal molecular transport mechanisms within the material, resulting in exceptional thermal, acoustical, mechanical, and electrical properties. For example, aerogels have the lowest measured thermal conductivity and dielectric constant for any solid material. Special methods are required to make aerogel films with high porosity. In this paper, we discuss the special conditions needed to fabricate aerogel films having porosities greater than 75% and we describe methods of processing inorganic aerogel films having controllable thicknesses in the range 0.5 to 200 micrometers. We report methods and results of characterizing the films including thickness, refractive index, density (porosity), and dielectric constant. We also discuss results of metallization and patterning on the aerogel films for applications involving microminiature electronics and thermal detectors.

  13. Evaluation of porosity in Al alloy die castings

    Directory of Open Access Journals (Sweden)

    M. Říhová

    2012-01-01

    Full Text Available Mechanical properties of an Al-alloy die casting depend significantly on its structural properties. Porosity in Al-alloy castings is one of the most frequent causes of waste castings. Gas pores are responsible for impaired mechanical-technological properties of cast materials. On the basis of a complex evaluation of experiments conducted on AlSi9Cu3 alloy samples taken from the upper engine block which was die- cast with and without local squeeze casting it can be said that castings manufactured without squeeze casting exhibit maximum porosity in the longitudinal section. The area without local squeeze casting exhibits a certain reduction in mechanical properties and porosity increased to as much as 5%. However, this still meets the norms set by SKODA AUTO a.s.

  14. [Improvement and application of digitized measure on shelterbelt porosity].

    Science.gov (United States)

    Guan, Wenbin; Li, Chunping; Li, Shifeng; Fan, Zhiping; Xie, Chunhua

    2002-06-01

    Based on the lots of investigation on farmland shelterbelts, we used digital camera to take pictures of shelterbelt and apply CIAS software to improve "digital image processing" for determining shelterbelt porosity so as to thoroughly analyze the rule of porosity in farmland shelterbelts. Compared with the old digital image processing, the improved method possesses high accuracy, and it is more economical and more convenient to apply. The relationship between porosity of shelterbelts (beta) and relative clear bole height (x) can be expressed as beta = 0.672x0.469 (r = 0.9851, r0.01 = 0.4073, 0 better than the rectangle one among the same tree species. UPPU and SPPS of mixed structure have the optimal effect in popular-willow-elm mixed shelterbelts.

  15. Limitation of Shrinkage Porosity in Aluminum Rotor Die Casting

    Science.gov (United States)

    Kim, Young-Chan; Choi, Se-Weon; Kim, Cheol-Woo; Cho, Jae-Ik; Lee, Sung-Ho; Kang, Chang-Seog

    Aluminum rotor prone to have many casting defects especially large amount of air and shrinkage porosity, which caused eccentricity, loss and noise during motor operation. Many attempts have been made to develop methods of shrinkage porosity control, but still there are some problems to solve. In this research, the process of vacuum squeeze die casting is proposed for limitation of defects. The 6 pin point gated dies which were in capable of local squeeze at the end ring were used. Influences of filling patterns on HPDC were evaluated and the important process control parameters were high injection speed, squeeze length, venting and process conditions. By using local squeeze and vacuum during filling and solidification, air and shrinkage porosity were significantly reduced and the feeding efficiency at the upper end ring was improved 10%. As a result of controlling the defects, the dynamometer test showed improved motor efficiency by more than 4%.

  16. Determining the Porosity and Saturated Hydraulic Conductivity of Binary Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.; Ward, Anderson L.; Keller, Jason M.

    2009-09-27

    Gravels and coarse sands make up significant portions of some environmentally important sediments, while the hydraulic properties of the sediments are typically obtained in the laboratory using only the fine fraction (e.g., <2 mm or 4.75 mm). Researchers have found that the content of gravel has significant impacts on the hydraulic properties of the bulk soils. Laboratory experiments were conducted to measure the porosity and the saturated hydraulic conductivity of binary mixtures with different fractions of coarse and fine components. We proposed a mixing-coefficient model to estimate the porosity and a power-averaging method to determine the effective particle diameter and further to predict the saturated hydraulic conductivity of binary mixtures. The proposed methods could well estimate the porosity and saturated hydraulic conductivity of the binary mixtures for the full range of gravel contents and was successfully applied to two data sets in the literature.

  17. Modified porosity rate frost heave model and tests verification

    Science.gov (United States)

    Ji, Zhi-qiang; Xu, Xue-yan

    2008-11-01

    To avoid the complexity of modeling frost heave from microscope, porosity rate function has been used in predication of frost heave phenomenon. The approach explored in this paper is based on frost heave tests and the concept of the segregated potential which has been widely accepted by researchers in order to find the proper form of the porosity rate function. In the frozen fringe the porosity rate function was derived: n•=Be(-aPe) (gradT)2 (1-n) , (Tstests were carried out to verify the model, and the comparison between test results and analog results shows that the modified model is efficient for the prediction of frost heave, and it can be used in engineering practice.

  18. Procedure for Uranium-Molybdenum Density Measurements and Porosity Determination

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-08-13

    The purpose of this document is to provide guidelines for preparing uranium-molybdenum (U-Mo) specimens, performing density measurements, and computing sample porosity. Typical specimens (solids) will be sheared to small rectangular foils, disks, or pieces of metal. A mass balance, solid density determination kit, and a liquid of known density will be used to determine the density of U-Mo specimens using the Archimedes principle. A standard test weight of known density would be used to verify proper operation of the system. By measuring the density of a U-Mo sample, it is possible to determine its porosity.

  19. Chalk porosity and sonic velocity versus burial depth

    DEFF Research Database (Denmark)

    Fabricius, Ida Lykke; Gommesen, Lars; Krogsbøll, Anette Susanne

    2008-01-01

    but not pore-structure stiffening cementation in this presumably water-wet chalk. These results should improve the modeling of chalk background velocity for seismic inversion analysis. When describing the porosity-reducing process, pore-volume compressibility should probably be disregarded when correcting...... so that smectite-bearing chalk has a high Poisson's ratio in the water-saturated case, but a low value in the dry case. Oil-bearing chalk has up to 25 units higher porosity than water-saturated chalk at similar depth but similar velocity, probably because hydrocarbons prevent pore-filling cementation...

  20. Computational fluid dynamics simulations of a glass melting furnace

    Energy Technology Data Exchange (ETDEWEB)

    Egelja, A.; Lottes, S. A.

    2000-05-09

    The glass production industry is one of the major users of natural gas in the US, and approximately 75% of the energy produced from natural gas is used in the melting process. Industrial scale glass melting furnaces are large devices, typically 5 or more meters wide, and twice as long. To achieve efficient heat transfer to the glass melt below, the natural gas flame must extend over a large portion of the glass melt. Therefore modern high efficiency burners are not used in these furnaces. The natural gas is injected as a jet, and a jet flame forms in the flow of air entering the furnace. In most current glass furnaces the energy required to melt the batch feed stock is about twice the theoretical requirement. An improved understanding of the heat transfer and two phase flow processes in the glass melt and solid batch mix offers a substantial opportunity for energy savings and consequent emission reductions. The batch coverage form and the heat flux distribution have a strong influence on the glass flow pattern. This flow pattern determines to a significant extent the melting rate and the quality of glass.

  1. Heuristic algorithms for scheduling heat-treatment furnaces of steel ...

    Indian Academy of Sciences (India)

    treatment furnaces in a steel-casting foundry, a special problem of batch processor scheduling, ... production management is to maximize throughput and reduce flow time and WIP. This motivated the choice of ..... A computational experiment is appropriate in order to provide a perspective on the relative effectiveness of any ...

  2. Reliability of graphite furnace atomic absorption spectrometry as ...

    African Journals Online (AJOL)

    Purpose: To evaluate the comparative efficiency of graphite furnace atomic absorption spectrometry (GFAAS) and hydride generation atomic absorption spectrometry (HGAAS) for trace analysis of arsenic (As) in natural herbal products (NHPs). Method: Arsenic analysis in natural herbal products and standard reference ...

  3. Better VPS Fabrication of Crucibles and Furnace Cartridges

    Science.gov (United States)

    Holmes, Richard R.; Zimmerman, Frank R.; O'Dell, J. Scott; McKechnie, Timothy N.

    2003-01-01

    An experimental investigation has shown that by (1) vacuum plasma spraying (VPS) of suitable refractory metal alloys on graphite mandrels, and then (2) heat-treating the VPS alloy deposits under suitable conditions, it is possible to fabricate improved crucibles and furnace cartridges that could be used at maximum temperatures between 1,400 and 1,600 C and that could withstand chemical attack by the materials to be heated in the crucibles and cartridges. Taken by itself, the basic concept of fabricating furnace cartridges by VPS of refractory materials onto graphite mandrels is not new; taken by itself, the basic concept of heat treatment of VPS deposits for use as other than furnace cartridges is also not new; however, prior to this investigation, experimental crucibles and furnace cartridges fabricated by VPS had not been heat treated and had been found to be relatively weak and brittle. Accordingly, the investigation was directed toward determining whether certain combinations of (1) refractory alloy compositions, (2) VPS parameters, and (3) heat-treatment parameters could result in VPS-fabricated components with increased ductility.

  4. Optimization of burners in oxygen-gas fired glass furnace

    NARCIS (Netherlands)

    Kersbergen, M.J. van; Beerkens, R.G.C.; Sarmiento-Darkin, W.; Kobayashi, H.

    2012-01-01

    The energy efficiency performance, production stability and emissions of oxygen-fired glass furnaces are influenced by the type of burner, burner nozzle sizes, burner positions, burner settings, oxygen-gas ratios and the fuel distribution among all the burners. These parameters have been optimized

  5. Analysis of combustion efficiency in a pelletizing furnace

    Directory of Open Access Journals (Sweden)

    Rafael Simões Vieira de Moura

    Full Text Available Abstract The objective of this research is to assess how much the improvement in the combustion reaction efficiency can reduce fuel consumption, maintaining the same thermal energy rate provided by the reaction in a pelletizing furnace. The furnace for pelletizing iron ore is a complex thermal machine, in terms of energy balance. It contains recirculation fan gases and constant variations in the process, and the variation of a single process variable can influence numerous changes in operating conditions. This study demonstrated how the main variables related to combustion in the burning zone influence fuel consumption (natural gas from the furnace of the Usina de Pelotização de Fábrica (owned by VALE S/A, without changing process conditions that affect production quality. Variables were analyzed regarding the velocity and pressure of the fuel in the burners, the temperature of the combustion air and reactant gases, the conversion rate and the stoichiometric air/fuel ratio of the reaction. For the analysis, actual data of the furnace in operation was used, and for the simulation of chemical reactions, the software Gaseq® was used. The study showed that the adjustment of combustion reaction stoichiometry provides a reduction of 9.25% in fuel consumption, representing a savings of US$ 2.6 million per year for the company.

  6. Chloride ingress of carbonated blast furnace slag cement mortars

    NARCIS (Netherlands)

    Holthuizen, P.E.; Çopuroglu, O.; Polder, R.B.

    2017-01-01

    In the Netherlands civil engineering structures, such as overpasses, bridges and tunnels are generally built using blast furnace slag cement (BFSC, CEM III/B) concrete, because of its high resistance against chloride penetration. Although the Dutch experience regarding durability performance of BFSC

  7. Heuristic algorithms for scheduling heat-treatment furnaces of steel ...

    Indian Academy of Sciences (India)

    The scheduling of furnaces for heat-treatment of castings is of considerable interest as a large proportion of the total production time is the processing times of these ... Department of Management Studies, Indian Institute of Science, Bangalore 560 012; Singapore-MIT Alliance, School of Mechanical and Aerospace ...

  8. Reliability of graphite furnace atomic absorption spectrometry as ...

    African Journals Online (AJOL)

    Original Research Article. Reliability of graphite furnace atomic absorption spectrometry as alternative method for trace analysis of arsenic in natural medicinal products. Reem Saadi Khalid1*, ABM Helaluddin1, Reem Saadi Khalid1, Mohamed. Alaama1, Abdualrahman M Abdualkader1, Abdulrazak Kasmuri2 and Syed Atif.

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

    Directory of Open Access Journals (Sweden)

    A. B. Steblov

    2016-01-01

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

  10. Analysis of a furnace for heat generation using polydisperse biomass

    Energy Technology Data Exchange (ETDEWEB)

    Magalhaes, Edney Alves; Silva, Juarez de Sousa e; Silva, Jadir Nogueira da; Oliveira Filho, Delly [Universidade Federal de Vicosa (DEA/UFV), MG (Brazil). Dept. de Engenharia Agricola; Donzeles, Sergio Mauricio Lopes [Empresa de Pesquisa Agropecuaria de Minas Gerais (EPAMIG), Vicosa, MG (Brazil)

    2008-07-01

    In many agro-industrial activities, the processing of raw material generates a substantial amount of fine materials. Examples include the production of soluble coffee, processing of rice, and wood processing, among others. In many regions, these by-products keep piling up on the courtyard of companies or become an environmental problem for land dumps. However, detailed tests of these byproducts indicate that they are excellent sources of energy. With this in mind, a furnace was developed to generate clean and hot air, using the alimentation system for pneumatic transport. Wood sawdust was used as fuel for analysis. The obtained results were considered satisfactory, proven by the small heat losses, primarily by the non-burned carbon monoxide (less than 0.2%) and the cooling of the furnace (less than 2.5%) whereas the losses by the exhaust gases were a little more than 23%. The thermal efficiency of the furnace was considered high when compared to others with an indirect heating system, obtaining an average value of 73%. The developed furnace, beyond being efficient, allows the use of the waste from the wood industry, which is important in the reduction of environmental impacts and minimizing production costs associated with the acquisition of conventional energy. (author)

  11. Electrode immersion depth determination and control in electroslag remelting furnace

    Energy Technology Data Exchange (ETDEWEB)

    Melgaard, David K. (Albuquerque, NM); Beaman, Joseph J. (Austin, TX); Shelmidine, Gregory J. (Tijeras, NM)

    2007-02-20

    An apparatus and method for controlling an electroslag remelting furnace comprising adjusting electrode drive speed by an amount proportional to a difference between a metric of electrode immersion and a set point, monitoring impedance or voltage, and calculating the metric of electrode immersion depth based upon a predetermined characterization of electrode immersion depth as a function of impedance or voltage.

  12. COMPUTER SIMULATION OF DISPERSED MATERIALS MOTION IN ROTARY TILTING FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2016-01-01

    Full Text Available The article presents the results of computer simulation of dispersed materials motion in rotary furnaces with an inclined axis of rotation. Has been received new data on the dynamic layer work that enhances understanding of heat and mass transfer processes occurring in the layer. 

  13. REFINERY STAGE OF OXIDES RESTORATION IN ROTATIONAL FURNACES

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2012-01-01

    Full Text Available The article is devoted to research of process of the iron-containing waste recycling in rotary tilting furnaces, in particular, to the phenomenon of formation of ball iron at transition from hard-phase to liquid-phase stage of iron restoration from scale.

  14. Utilization of steel melting electric arc furnace slag for development ...

    Indian Academy of Sciences (India)

    ... but generates a new waste, electric arc furnace slag, which is getting accumulated and land/mine filling and road construction are the only utilization. This slag has been tried to be value added and utilized to develop vitreous ceramic tiles. Slag, to the extent of 30–40 wt% with other conventional raw materials, were used ...

  15. APPLICATIONS ANALYSIS REPORT: BABCOCK AND WILCOX CYCLONE FURNACE

    Science.gov (United States)

    This document is an evaluation of the performance of the Babcock & Wilcox (B&W) Cyclone Furnace Vitrification Technology and its applicability as a treatment technique for soils contaminated with heavy metals, radionuclides, and organics. oth the technical and economic aspects of...

  16. Sliding mode controllers for a tempered glass furnace.

    Science.gov (United States)

    Almutairi, Naif B; Zribi, Mohamed

    2016-01-01

    This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system's parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Reflectance analysis of porosity gradient in nanostructured silicon layers

    Science.gov (United States)

    Jurečka, Stanislav; Imamura, Kentaro; Matsumoto, Taketoshi; Kobayashi, Hikaru

    2017-12-01

    In this work we study optical properties of nanostructured layers formed on silicon surface. Nanostructured layers on Si are formed in order to reach high suppression of the light reflectance. Low spectral reflectance is important for improvement of the conversion efficiency of solar cells and for other optoelectronic applications. Effective method of forming nanostructured layers with ultralow reflectance in a broad interval of wavelengths is in our approach based on metal assisted etching of Si. Si surface immersed in HF and H2O2 solution is etched in contact with the Pt mesh roller and the structure of the mesh is transferred on the etched surface. During this etching procedure the layer density evolves gradually and the spectral reflectance decreases exponentially with the depth in porous layer. We analyzed properties of the layer porosity by incorporating the porosity gradient into construction of the layer spectral reflectance theoretical model. Analyzed layer is splitted into 20 sublayers in our approach. Complex dielectric function in each sublayer is computed by using Bruggeman effective media theory and the theoretical spectral reflectance of modelled multilayer system is computed by using Abeles matrix formalism. Porosity gradient is extracted from the theoretical reflectance model optimized in comparison to the experimental values. Resulting values of the structure porosity development provide important information for optimization of the technological treatment operations.

  18. Porosity of free boundaries in the obstacle problem for quasilinear ...

    Indian Academy of Sciences (India)

    Indian Acad. Sci. (Math. Sci.) Vol. 123, No. 3, August 2013, pp. 373–382. c Indian Academy of Sciences. Porosity of free boundaries in the obstacle problem ... 2School of Mathematical Sciences, University of Electronic Science and Technology of China, Chengdu ... conditions for some positive constants γ0,γ1, namely. N. ∑.

  19. Relating wood properties to handsheet porosity and mechanical strength

    CSIR Research Space (South Africa)

    Maharaj, S

    2006-11-01

    Full Text Available to hand- sheet porosity and mechanical strength S. Maharaj1,3, J. Wesley-Smith2 and T. Bush3 1School of Biological and Conservation Sciences, University of KwaZulu-Natal, Durban, 4041 2Electron Microscope Unit, University of KwaZulu-Natal, Durban...

  20. Tuning porosity via control of interpenetration in a zinc isonicotinate ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 126; Issue 5. Tuning porosity via control of interpenetration in a zinc isonicotinate metal organic framework. Shyamapada Nandi Ramanathan Vaidhyanathan. Special issue on Chemical Crystallography Volume 126 Issue 5 September 2014 pp 1393-1398 ...

  1. A dual porosity model of nutrient uptake by root hairs

    KAUST Repository

    Zygalakis, K. C.

    2011-08-09

    Summary: • The importance of root hairs in the uptake of sparingly soluble nutrients is understood qualitatively, but not quantitatively, and this limits efforts to breed plants tolerant of nutrient-deficient soils. • Here, we develop a mathematical model of nutrient uptake by root hairs allowing for hair geometry and the details of nutrient transport through soil, including diffusion within and between soil particles. We give illustrative results for phosphate uptake. • Compared with conventional \\'single porosity\\' models, this \\'dual porosity\\' model predicts greater root uptake because more nutrient is available by slow release from within soil particles. Also the effect of soil moisture is less important with the dual porosity model because the effective volume available for diffusion in the soil is larger, and the predicted effects of hair length and density are different. • Consistent with experimental observations, with the dual porosity model, increases in hair length give greater increases in uptake than increases in hair density per unit main root length. The effect of hair density is less in dry soil because the minimum concentration in solution for net influx is reached more rapidly. The effect of hair length is much less sensitive to soil moisture. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  2. [Aortobifemoral prostheses with "0" porosity. Results after 2 years' experience].

    Science.gov (United States)

    Escudero, J R; Llagostera, S; Riambau, V; Latorre, E; Upegui, L; Pastor, O; Viver, E

    1990-01-01

    During the last years diverse types of Dacron prosthesis without porosity (because to be impregnated by different materials) have appeared. In the presented study, outcomes from three different types of prosthesis (differentiated by the impregnated material) were evaluated and a comparison with classical prosthesis was made.

  3. Estimation of porosity and hydraulic conductivity of shallow ...

    African Journals Online (AJOL)

    In this study, two theoretical methods based respectively on Archie-Kozeny equations and Ohm's-Darcy's laws were used to determine porosity and hydraulic conductivity of shallow aquifer in Yenagoa, Southern Nigeria. Fourteen Vertical Electrical Soundings (VES) using the Schlumberger configuration were carried out ...

  4. Effects of sintering temperature on the density and porosity

    African Journals Online (AJOL)

    2013-03-01

    Mar 1, 2013 ... perative. Hence the aim of this paper is to critically investi- gate the effects of sintering temperature on the density and porosity of salt bead preforms used in the liquid infiltration of aluminium for open cell foam manufac- turing. 2. Sintering Mechanism. Sintering occurs by atomic diffusion processes that.

  5. Influence of porosity on mechanical properties of tetragonal stabilized zirconia

    DEFF Research Database (Denmark)

    Boccaccini, Dino; Frandsen, Henrik Lund; Soprani, Stefano

    2017-01-01

    3YSZ specimens with variable open porosity (1–57%) were fabricated, and the stiffness, strength and fracture properties (fracture toughness and R-curve) were measured to investigate their potential use as support structures for solid oxide fuel or electrolysis cells. The ball-on-ring test was use...

  6. Measurements of the evolution of porosity in a mushy layer

    Science.gov (United States)

    Jahrling, Katia; Tait, Stephen

    1996-09-01

    We suggest improvements to an experimental technique designed to make local measurements of liquid volume fraction, or porosity, in a mushy layer that forms during dynamic solidification of a multicomponent melt. In a set of control experiments we measured the electrical resistance of a medium of known porosity in which the solid particles were Fontainebleau sand, and the electrolytes were aqueous solutions of ammonium chloride. The results confirm that an appropriate description can be obtained using Archie's law with a cementation exponent of 1.5. In a second set of experiments we solidified aqueous solutions of ammonium chloride by cooling from below under conductive conditions. The solid phase formed was ice with a plate-like morphology, and we compared values of porosity obtained from the electrical measurements with those deduced from temperature measurements assuming local thermodynamic equilibrium. The results indicate that this progressively solidifying porous medium can also be described by Archie's law, and good agreement between electrical and thermal porosities is obtained for a cementation exponent of 1.72. We interpret this higher value as implying a higher tortuosity for this porous medium when compared with that made of Fontainebleau sand.

  7. Direct synthesis of metal nanoparticles with tunable porosity

    NARCIS (Netherlands)

    Detsi, Eric; Punzhin, Sergey; Onck, Patrick R.; De Hosson, Jeff Th. M.

    2012-01-01

    Herein, we report a facile one-step synthesis route of porous bimetallic Au-Ag nanoparticles involving two parallel processes: alloying during nanocrystal growth and dealloying via galvanic replacement reaction. Further, we show that porosity in these nanoparticles can be tuned via their alloy

  8. Porosity and compaction trend in Okan field (Western Niger Delta ...

    African Journals Online (AJOL)

    The main hydrocarbon trap results from vertical stacking of porous reservoirs sands while the stratigraphic trap is evident from reservoir Pinchouts. Global Journal of Pure and Applied Sciences Volume , No 1 January (2001) pp. 91-96. KEY WORDS: Porosity, Reservoir, Sedimentation, Overpressure, Hydrocarbon.

  9. Compaction and Porosity Based Pore Pressure Prediction in the ...

    African Journals Online (AJOL)

    Three wells of the “Cappe” Field in the offshore part of the Coastal Swamp depobelt I, Niger Delta, were evaluated primarily to determine the impact of compaction on reservoir quality and to determine possible over-pressured zones in the Benin and Agbada formations. Sandstone porosity-depth plots of the three wells show ...

  10. Mechanisms and mechanics of porosity formation in ductile iron castings

    Directory of Open Access Journals (Sweden)

    M. Perzyk

    2007-12-01

    Full Text Available Shrinkage defects in ductile iron castings can be of two basic types: shrinkage cavities associated with the liquid contraction prior to the expansion period of the iron as well as the porosity, which may appear even if the liquid shrinkage is fully compensated. In the present paper two possible mechanisms of the porosity are presented and analyzed. The first one is the Karsay’s mechanism based on the secondary shrinkage concept. The second one is the mechanism acting during the expansion period of the iron, first suggested by Ohnaka and co-authors and essentially modified by the present authors. The mechanical interactions between casting and mould are determined for the both mechanisms. Their analysis leads to the conclusion, that porosity forms during expansion period of the melt. The direct cause is the negative pressure which appears in the central part of the casting due to the differences in expansion coefficients of the fast cooling surface layer and slow cooling inner region. Observations concerning feeding behavior of ductile iron castings, based on this mechanism, agree well with industrial practice. The secondary shrinkage is not only needless to induce the porosity, but the corresponding mechanism of its occurrence, proposed by Karsay, does not seem to be valid.

  11. The porosity in a fluidized bed heat transfer model

    NARCIS (Netherlands)

    Visser, G; Visser, G.; Valk, M.

    1993-01-01

    A mathematical model of heat transfer between a fluidized bed and an immersed surface and a model of gas flow and porosity, both recently published, were combined and further modified in the area of low velocities where the particle convective component of heat transfer is low or neglectable.

  12. Understanding age-induced cortical porosity in women

    DEFF Research Database (Denmark)

    Andreasen, Christina Møller; Delaisse, Jean-Marie; van der Eerden, Bram C J

    2018-01-01

    of a histomorphometric analysis of sections of iliac bone specimens from 35 women (age 16-78 years). Firstly, the study shows that the aging-induced cortical porosity reflects an increased pore size rather than an increased pore density. Secondly, it establishes a novel histomorphometric classification of the pores...

  13. Brayton-Cycle Heat Recovery System Characterization Program. Glass-furnace facility test plan

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-29

    The test plan for development of a system to recover waste heat and produce electricity and preheated combustion air from the exhaust gases of an industrial glass furnace is described. The approach is to use a subatmospheric turbocompressor in a Brayton-cycle system. The operational furnace test requirements, the operational furnace environment, and the facility design approach are discussed. (MCW)

  14. 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...

  15. Increased cortical porosity in women with hip fracture.

    Science.gov (United States)

    Sundh, D; Nilsson, A G; Nilsson, M; Johansson, L; Mellström, D; Lorentzon, M

    2017-05-01

    Hip fractures cause increased mortality and disability and consume enormous healthcare resources. Only 46% of hip fracture patients have osteoporosis at the total hip according to dual-energy X-ray absorptiometry (DXA) measurement. Cortical porosity increases with ageing and is believed to be important for bone strength. To investigate whether older women with hip fracture have higher cortical porosity than controls, and if so whether this difference is independent of clinical risk factors and areal bone mineral density (aBMD). From an ongoing population-based study, we identified 46 women with a prevalent X-ray-verified hip fracture and 361 control subjects without any fractures. aBMD was measured with DXA. High-resolution peripheral quantitative computed tomography was used to measure bone microstructure at the standard (ultradistal) site and at 14% (distal) of the tibial length. Women with a previous hip fracture had lower aBMD at the femoral neck (-11.8%) and total hip (-14.6%) as well as higher cortical porosity at the ultradistal (32.1%) and distal (29.3%) tibia compared with controls. In multivariable logistic regression analysis, with adjustment for covariates (age, height, weight, smoking, calcium intake, physical activity, walk time, oral glucocorticoids, parental hip fracture, rheumatoid arthritis, previous fall, current bisphosphonate treatment and femoral neck aBMD), cortical porosity at the ultradistal [odds ratio per standard deviation increase (95% confidence interval) 2.61 (1.77-3.85)] and distal [1.57 (1.12-2.20)] sites was associated with prevalent hip fracture. Cortical porosity was associated with prevalent hip fracture in older women independently of femoral neck aBMD and clinical risk factors. © 2017 The Authors. Journal of Internal Medicine published by John Wiley & Sons Ltd on behalf of Association for Publication of The Journal of Internal Medicine.

  16. A Novel Porosity Model for Use in Hydrocode Simulations

    Science.gov (United States)

    Wuennemann, K.; Collins, G. S.; Melosh, H. J.

    2005-01-01

    Introduction: Numerical modeling of impact cratering has reached a high degree of sophistication; however, the treatment of porous materials still poses a large problem in hydrocode calculations. Porosity plays only a minor role in the formation of large craters on most planetary objects, but impacts on comets are believed to be highly affected by the presence of porosity, which may be as much as 80%. The upcoming Deep Impact Mission (launched January 2005) will provide more detailed data about the composition of a comet (Tempel 1) by shooting a approx.370 kg projectile onto the surface of its nucleus. The numerical simulations of such impact events requires an appropriate model for how pore space in the comet is crushed out during the violent initial stage of the impact event. Most hydro-codes compute the pressure explicitly using an "equation of state" (EOS) for each material, which relates changes in density and internal energy to changes in pressure. The added complication introduced by porosity is that changes in a material s density are due to both the closing of pore space (compaction) and compression of the matrix. The amount of resistance to volume change and the amount of irreversible work done during these two processes is very different; it is far easier to compact a porous material sample than to compress a non-porous sample of the same material. As an alternative to existing porosity models, like the Pdot(alpha) model [1], we present a novel approach for dealing with the compaction of porosity in hydrocode calculations.

  17. Effect of bond coat and preheat on the microstructure, hardness, and porosity of flame sprayed tungsten carbide coatings

    Science.gov (United States)

    Winarto, Winarto; Sofyan, Nofrijon; Rooscote, Didi

    2017-06-01

    Thermally sprayed coatings are used to improve the surface properties of tool steel materials. Bond coatings are commonly used as intermediate layers deposited on steel substrates (i.e. H13 tool steel) before the top coat is applied in order to enhance a number of critical performance criteria including adhesion of a barrier coating, limiting atomic migration of the base metal, and corrosion resistance. This paper presents the experimental results regarding the effect of nickel bond coat and preheats temperatures (i.e. 200°C, 300°C and 400°C) on microstructure, hardness, and porosity of tungsten carbide coatings sprayed by flame thermal coating. Micro-hardness, porosity and microstructure of tungsten carbide coatings are evaluated by using micro-hardness testing, optical microscopy, scanning electron microscopy, and X-ray diffraction. The results show that nickel bond coatings reduce the susceptibility of micro crack formation at the bonding area interfaces. The percentage of porosity level on the tungsten carbide coatings with nickel bond coat decreases from 5.36 % to 2.78% with the increase of preheat temperature of the steel substrate of H13 from 200°C to 400°C. The optimum hardness of tungsten carbide coatings is 1717 HVN in average resulted from the preheat temperature of 300°C.

  18. 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)

  19. Porosity of an Anhydrous Chondritic Interplanetary Dust Particle

    Science.gov (United States)

    Strait, M. M.; Thomas, K. L.; McKay, D. S.

    1995-09-01

    Determination of the density and porosity of Interplanetary Dust Particles (IDPs) is important in the dynamics of collisional and orbital evolution of small-sized particles. These measurements are also useful to suggest possible sources for IDPs based on comparisons with known extraterrestrial materials (e.g., chondrites). Previous work on IDPs shows a wide range of densities from very low (0.08 g/cm3 [1]) through low (0.3 g/cm3 [2]) to high (6.2 g/cm3 [3]), with an average density at 2.0 g/cm3 for 150 particles [2]. In another study, IDPs fall into two distinct density groups with mean values of 0.6 g/cm3 and 1.9g/cm3 [3]. In general, chondritic IDPs with lower density values most likely have appreciable porosity, suggesting they are primitive, uncompacted particles. It is believed that porosities greater than 70% are rare [2]. Sample In this study, porosity measurements were determined for one IDP, Clu17. This chondritic particle is a fragment of a large-sized IDP (L2008#5) known as a cluster particle. The cluster is composed of 53 fragments >5 micrometers in diameter; a detailed description of the cluster is given in [4]. IDP Clu17 has ~12 wt.% C and contains chondritic abundances (within 2xCI) for major elements. This fragment is dominated by fine-grained aggregates, also known as GEMS (glass with embedded metal and sulfide [5]), and contains some olivine, pyroxene, Fe-Ni sulfides, and carbonaceous material. Methods IDP Clu17 was analyzed for light elements quantitatively analysis using scanning electron microscopy and thin-window energy dispersive spectrometry [details of technique in 4]. Following the initial bulk chemical analysis, the particle was embedded in epoxy, thin sectioned using an ultramicrotome, and examined with a JEOL 2000 FX transmission electron microscope. Many of the sections were not complete; individual grains in some sections are lost during microtoming. Photos from nine of the best sections were digitized by scanning at 1200 dpi. The

  20. Numerical Computation of Net Radiative Heat Transfer within a Non Absorbing Furnace Enclosure

    Directory of Open Access Journals (Sweden)

    Shuaibu Ndache MOHAMMED

    2006-07-01

    Full Text Available The numerical evaluation of the net radiative heat transfer rate in a single zone, non absorbing furnace enclosure is reported. In this analysis, simplified mathematical furnace model namely, the long furnace model is used to determine furnace performance. The formulation assumes some known temperature values. Thus, heat transfer equations were set up and solved numerically. A FORTRAN computer program was developed and debugged. Results obtained from this study compare favourably well with the results from the traditional graphical method. Also, the computer program developed can handle variations in furnace operating conditions, temperatures, thermal properties and dimensions.

  1. CFD simulation of gas and particles combustion in biomass furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Griselin, Nicolas

    2000-11-01

    In this thesis, gas and particle combustion in biomass furnaces is investigated numerically. The aim of this thesis is to use Computational Fluid Dynamics (CFD) technology as an effective computer based simulation tool to study and develop the combustion processes in biomass furnaces. A detailed model for the numerical simulation of biomass combustion in a furnace, including fixed-bed modeling, gas-phase calculation (species distribution, temperature field, flow field) and gas-solid two-phase interaction for flying burning particles is presented. This model is used to understand the mechanisms of combustion and pollutant emissions under different conditions in small scale and large scale furnaces. The code used in the computations was developed at the Division of Fluid Mechanics, LTH. The flow field in the combustion enclosure is calculated by solving the Favre-averaged Navier-Stokes equations, with standard {kappa} - {epsilon} turbulence closure, together with the energy conservation equation and species transport equations. Discrete transfer method is used for calculating the radiation source term in the energy conservation equation. Finite difference is used to solve the general form of the equation yielding solutions for gas-phase temperatures, velocities, turbulence intensities and species concentrations. The code has been extended through this work in order to include two-phase flow simulation of particles and gas combustion. The Favre-averaged gas equations are solved in a Eulerian framework while the submodels for particle motion and combustion are used in the framework of a Lagrangian approach. Numerical simulations and measurement data of unburned hydrocarbons (UHC), CO, H{sub 2}, O{sub 2} and temperature on the top of the fixed bed are used to model the amount of tar and char formed during pyrolysis and combustion of biomass fuel in the bed. Different operating conditions are examined. Numerical calculations are compared with the measured data. It is

  2. 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.

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

    Directory of Open Access Journals (Sweden)

    Hatakeyama Keisuke

    2016-01-01

    Full Text Available Metallurgical grade silicon was formed using Shirasu volcanic ash as starting material with solar furnace. The solar furnace was composed of two parts: Fresnel lens and reacting furnace. The reacting furnace was composed of a cylindrical vacuum chamber and quartz glass plate functioning to guide the concentrated sunlight into the furnace, and was placed at the focal point of the Fresnel lens. The sample was made from a mixture of silica formed from Shirasu volcanic ash and carbon, and placed in the carbon crucible inside the reacting furnace. The sample was irradiated for 3 hours, and the furnace was left until it cooled down to room temperature. After the cooling process, the sample was mixed and placed in the carbon crucible, and it was irradiated and cooled with the same processes again. After the experiment, the sample was evaluated by X-ray diffraction and the production of silicon was confirmed.

  4. Carbon composition with hierarchical porosity, and methods of preparation

    Science.gov (United States)

    Mayes, Richard T; Dai, Sheng

    2014-10-21

    A method for fabricating a porous carbon material possessing a hierarchical porosity, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic component, (iii) a dione component in which carbonyl groups are adjacent, and (iv) an acidic component, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a carbon material possessing a hierarchical porosity comprised of mesopores and macropores. Also described are the resulting hierarchical porous carbon material, a capacitive deionization device in which the porous carbon material is incorporated, as well as methods for desalinating water by use of said capacitive deionization device.

  5. Elastic Equilibrium of Porous Cosserat Media with Double Porosity

    Directory of Open Access Journals (Sweden)

    Roman Janjgava

    2016-01-01

    Full Text Available The static equilibrium of porous elastic materials with double porosity is considered in the case of an elastic Cosserat medium. The corresponding three-dimensional system of differential equations is derived. Detailed consideration is given to the case of plane deformation. A two-dimensional system of equations of plane deformation is written in the complex form and its general solution is represented by means of three analytic functions of a complex variable and two solutions of Helmholtz equations. The constructed general solution enables one to solve analytically a sufficiently wide class of plane boundary value problems of the elastic equilibrium of porous Cosserat media with double porosity. A concrete boundary value problem for a concentric ring is solved.

  6. Prediction of Surface Porosity Defects in High Pressure Die Casting

    Science.gov (United States)

    Saeedipour, Mahdi; Schneiderbauer, Simon; Pirker, Stefan; Bozorgi, Salar

    High pressure die casting (HPDC) is a novel manufacturing method with capability of mass production with higher accuracy. Porosity is one of the challenging defects in final product and may be affected by jet instability and atomization during injection phase. In case of atomization a large number of droplets with high velocity impinges the colder confining walls of the casting mold and might solidify consecutively. Different time scales of the impingement of the droplets and their solidification may result in heterogeneous structures near the surface of final product. A numerical framework using volume of fluid method (VOF) and an Eulerian-Lagrangian approach is established to simulate the liquid metal jet breakup and droplet formation during the injection phase. An analytical model for droplet impact on mold walls and solidification is studied and implemented in the numerical framework. The latter enables the prediction of porosity formation near the surface of final product.

  7. Porosity and Inclusion Detection in CFRP by Infrared Thermography

    Directory of Open Access Journals (Sweden)

    C. Toscano

    2012-01-01

    Full Text Available The ever wide use of composite materials in the aeronautical industry has evidenced the need for development of ever more effective nondestructive evaluation methodologies in order to reduce rejected parts and to optimize production costs. Infrared thermography has been recently enclosed amongst the standardized non destructive testing techniques, but its usefulness needs still complete assessment since it can be employed in several different arrangements and for many purposes. In this work, the possibility to detect slag inclusions and porosity is analyzed with both lock-in themography and pulse thermography in the transmission mode. To this end, carbon-fiber-peinforced polymers different specimens are specifically fabricated of several different stacking sequences and with embedded slag inclusions and porosity percentages. As main results, both of the techniques are found definitely able to reveal the presence of the defects above mentioned. Moreover, these techniques could be considered complementary in order to better characterize the nature of the detected defects.

  8. Using low porosity refractory materials in coke ovens

    Energy Technology Data Exchange (ETDEWEB)

    Narita, Y.; Sudzuki, T.

    1982-02-19

    Refractory bricks with porosity (KP) of less than or equal to 17 percent, which contain less than 1 percent iron oxide and are resiliant at temperatures of more than 1,000/sup 0/C, are made through caking or electrosmelting of materials with a high aluminum content (chamotte, sillimanite, cordierite, pagodite) and silicon content (magnesial chromite, alumina, magnesite, calcite and zircon). In a refractory material with a seeming porosity of less than or equal to 17 percent the deposition of carbon in the pores is reduced which promotes a constant heat conductivity and strength of the refractory material in the operation of coke ovens. Normally the carbon is formed with the reduction of CO under the catalytic action of iron oxide.

  9. Metals Ions Removal by Polymer Membranes of Different Porosity

    Directory of Open Access Journals (Sweden)

    Katarzyna Jasiewicz

    2013-01-01

    Full Text Available The effect of the amount of pore generating agent (polyvinylpyrrolidone added to standard polymer membranes containing 18 wt.% of polyethersulfone on the physicochemical properties of the membranes and their capacity for removal of iron and copper ions from the liquid phase was studied. The membranes were obtained by the phase inversion method. The results have shown that the modification of polymer membranes by the use of different amounts of the pore forming agent in their syntheses leads to significant changes in porosity and has beneficial effect on equilibrium water content. The membranes studied were found to show different acid-base surface character, but for all membranes studied, a significant dominance of oxygen groups of acidic character was evidenced. The most effective were the membranes of the lowest content of polyvinylpyrrolidone, while the lowest values of resistance showed the membranes of the highest content of PVP, and so the ones of the greatest porosity.

  10. Microstructure, porosity and mineralogy around fractures in Olkiluoto bedrock

    Energy Technology Data Exchange (ETDEWEB)

    Kuva, J. (ed.); Myllys, M.; Timonen, J. [Jyvaeskylae Univ. (Finland); Kelokaski, M.; Ikonen, J.; Siitari-Kauppi, M. [Helsinki Univ. (Finland); Lindberg, A. [Geological Survey of Finland, Espoo (Finland); Aaltonen, I.

    2012-01-15

    3D distributions of minerals and porosities were determined for samples that included waterconducting fractures. The analysis of these samples was performed using conventional petrography methods, electron microscopy, C-14-PMMA porosity analysis and X-ray tomography. While X-ray tomography proved to be a very useful method when determining the inner structure of the samples, combining tomography results with those obtained by other methods turned out to be difficult without very careful sample preparation design. It seems that the properties of rock around a water-conducting fracture depend on so many uncorrelated factors that no clear pattern emerged even for rock samples with a given type of fracture. We can conclude, however, that a combination of different analysis methods can be useful and used to infer novel structural information about alteration zones adjacent to fracture surfaces. (orig.)

  11. Porosity Evolution in a Creeping Single Crystal (Preprint)

    Science.gov (United States)

    2012-08-01

    mechanism. Our analyses focus on the role of stress state on deformation and void growth in ductile single crystals in the dislocation creep regime. We also...orientation effects on void growth and coalescence in fcc single crystals . International Journal of Plasticity, 22, 921-942. [27] Kysar J.W., Gan Y.X...AFRL-RX-WP-TP-2012-0373 POROSITY EVOLUTION IN A CREEPING SINGLE CRYSTAL (PREPRINT) A. Srivastava and A. Needleman University of North

  12. Recycling MgO-C refractory in electric arc furnaces

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-11-15

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

  13. Fuzzy Logic Temperature Control System For The Induction Furnace

    Directory of Open Access Journals (Sweden)

    Lei Lei Hnin

    2015-08-01

    Full Text Available This research paper describes the fuzzy logic temperature control system of the induction furnace. Temperature requirement of the heating system varies during the heating process. In the conventional control schemes the switching losses increase with the change in the load. A closed loop control is required to have a smooth control on the system. In this system pulse width modulation based power control scheme for the induction heating system is developed using the fuzzy logic controller. The induction furnace requires a good voltage regulation to have efficient response. The controller controls the temperature depending upon weight of meat water and time. This control system is implemented in hardware system using microcontroller. Here the fuzzy logic controller is designed and simulated in MATLAB to get the desire condition.

  14. Orgin of Slag from Early Medieval Age Furnaces in Nitra

    Directory of Open Access Journals (Sweden)

    Julius Dekan

    2005-01-01

    Full Text Available Two types of archaeological artefacts from remains of Early Medieval Age furnaces excavated in Nitra are analysed. They are supposed to originate from slag of glass and iron production. Employing Mossbauer spectrometry, iron crystallographic sites are identified and compared. In all samples, Fe2+ and Fe3+ structural positions were revealed. Some of the archeological artefacts including those that were supposed to originate from glass production show a presence of metallic iron and/or magnetic oxides. Based on the results of Mossbauer effect measurements performed at room temperature as well as 77 K (liquid nitrogen temperature analytical evidence is provided that the iron sites identified are not as those usually encountered in glasses. Consequently, a conclusion is proposed that neither of the investigated furnaces was used for glass production.

  15. Annealing furnace for III-V semiconductor devices

    Science.gov (United States)

    O'Connor, J. M.; Hier, H. S.; Ketchum, R. M.

    1986-02-01

    A furnace for annealing ion implantation damage in III-V semiconductors has been built and tested. Designed for research applications, the furnace can accommodate odd shapes of material up to 2 in. in diameter. Samples are loaded onto a novel cantilevered support and are not moved during the annealing operation, facilitating proximity annealing techniques. Both chambers of this dual chambered system are O-ring sealed for added safety during annealing in an arsine gas ambient. Electron mobilities between 4400 and 4600 cm2/V s at 300 K are routinely measured for 2×1017 cm-3 gallium arsenide material annealed in this sytem. The system has been used to anneal indium phosphide as well as gallium arsenide wafers.

  16. Advanced wood burning furnaces. 2. rev. ed.; Moderne Holzfeuerungsanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, W. (comp.)

    2001-07-01

    New and environment-friendly technologies meet high requirements in terms of emission reduction and comfort of operation. In the field of wood burning furnaces, there is still a lack of knowledge which results in excessive cost, environmental pollution and loss of image. This brochure shows how wood furnaces should be operated correctly and also reviews the state of the art. [German] Durch die technische Entwicklung neuer, wirkungsvoller und vor allem umweltfreundlicher Heiztechniken wird zudem den in den letzten Jahren gestiegenen Anforderungen an den Emissionsschutz und den Bedienungskomfort Rechnung getragen. Mit Holz wird jedoch z. T. nicht immer richtig geheizt. Das kostet Geld und fuehrt zu vermeidbaren Umweltbelastungen und Imageschaeden. Ziel dieser Broschuere ist es daher, mit den Techniken des Heizens mit Holz vertraut zu machen und einen Ueberblick ueber den heutigen Stand zu geben. (orig.)

  17. SIMULATION ANALYSIS OF PREHEATER CHARGE TO THE ROTARY FURNACE

    Directory of Open Access Journals (Sweden)

    Jan Mikula

    2015-08-01

    Full Text Available Mathematical modeling of heat aggregates is one of the fundamental methods of the mathematical modelling research. A mathematical model based on the method of elementary balances was created for the thermal treatment of granular and lumpy materials. The adaptation of the selected aggregate model is based on prior knowledge and experiments. The paper presents an adaptation of the mathematical model for the magnesite processing rotary furnace using the mode of caustic and clinker production. A simulation of the charge preheater impact based on the thin layer principle is implemented into the model. The main advantages of using this type of preheater of rotary furnace are smaller dimensions for a large exchange surface and low pressure losses.

  18. Thermal Spray Coatings for Blast Furnace Tuyere Application

    Science.gov (United States)

    Pathak, A.; Sivakumar, G.; Prusty, D.; Shalini, J.; Dutta, M.; Joshi, S. V.

    2015-12-01

    The components in an integrated steel plant are invariably exposed to harsh working environments involving exposure to high temperatures, corrosive gases, and erosion/wear conditions. One such critical component in the blast furnace is the tuyere, which is prone to thermal damage by splashing of molten metal/slag, erosive damage by falling burden material, and corrosion from the ensuing gases. All the above, collectively or independently, accelerate tuyere failure, which presents a potential explosion hazard in a blast furnace. Recently, thermal spray coatings have emerged as an effective solution to mitigate such severe operational challenges. In the present work, five different coatings deposited using detonation spray and air plasma spray techniques were comprehensively characterized. Performance evaluation involving thermal cycling, hot corrosion, and erosion tests was also carried out. Based on the studies, a coating system was suggested for possible tuyere applications and found to yield substantial improvement in service life during actual field trials.

  19. Injectable PolyHIPEs as High Porosity Bone Grafts

    Science.gov (United States)

    Moglia, Robert S.; Holm, Jennifer L.; Sears, Nicholas A.; Wilson, Caitlin J.; Harrison, Dawn M.; Cosgriff-Hernandez, Elizabeth

    2011-01-01

    Polymerization of high internal phase emulsions (polyHIPEs) is a relatively new method for the production of high porosity scaffolds. The tunable architecture of these polyHIPE foams make them attractive candidates for tissue engineered bone grafts. Previously studied polyHIPE systems require either toxic diluents or high cure temperatures which prohibit their use as an injectable bone graft. In contrast, we have developed an injectable polyHIPE that cures at physiological temperatures to a rigid, high-porosity foam. First, a biodegradable macromer, propylene fumarate dimethacrylate (PFDMA), was synthesized that has appropriate viscosity and hydrophobicity for emulsification. The process of surfactant selection is detailed with particular focus on the key structural features of both polymer (log P values, hydrogen bond acceptor sites) and surfactant (HLB values, hydrogen bond donor sites) that enable stable HIPE formation. Incubation of HIPEs at 37°C was used to initiate radical crosslinking of the unsaturated double bond of the methacrylate groups to polymerize the continuous phase and lock in the emulsion geometry. The resulting polyHIPEs exhibited ~75% porosity, pore sizes ranging from 4 to 29 μm, and an average compressive modulus and strength of 33 and 5 MPa, respectively. These findings highlight the great potential of these scaffolds as injectable, tissue engineered bone grafts. PMID:21861465

  20. Injectable polyHIPEs as high-porosity bone grafts.

    Science.gov (United States)

    Moglia, Robert S; Holm, Jennifer L; Sears, Nicholas A; Wilson, Caitlin J; Harrison, Dawn M; Cosgriff-Hernandez, Elizabeth

    2011-10-10

    Polymerization of high internal phase emulsions (polyHIPEs) is a relatively new method for the production of high-porosity scaffolds. The tunable architecture of these polyHIPE foams makes them attractive candidates for tissue engineered bone grafts. Previously studied polyHIPE systems require either toxic diluents or high cure temperatures which prohibit their use as an injectable bone graft. In contrast, we have developed an injectable polyHIPE that cures at physiological temperatures to a rigid, high-porosity foam. First, a biodegradable macromer, propylene fumarate dimethacrylate (PFDMA), was synthesized that has appropriate viscosity and hydrophobicity for emulsification. The process of surfactant selection is detailed with particular focus on the key structural features of both polymer (logP values, hydrogen bond acceptor sites) and surfactant (HLB values, hydrogen bond donor sites) that enable stable HIPE formation. Incubation of HIPEs at 37 °C was used to initiate radical cross-linking of the unsaturated double bond of the methacrylate groups to polymerize the continuous phase and lock in the emulsion geometry. The resulting polyHIPEs exhibited ~75% porosity, pore sizes ranging from 4 to 29 μm, and an average compressive modulus and strength of 33 and 5 MPa, respectively. These findings highlight the great potential of these scaffolds as injectable, tissue engineered bone grafts.

  1. Acoustic properties of double-porosity granular polymers

    Science.gov (United States)

    Alevizaki, A.; Sainidou, R.; Rembert, P.; Morvan, B.; Stefanou, N.

    2017-06-01

    Using an extension of the full elastodynamic layer-multiple-scattering method to structures of fluid-saturated poroelastic spherical bodies, a comprehensive theoretical study of the acoustic response of double-porosity submerged liquid-saturated granular polymeric materials of specific morphology consisting of touching porous polymer spheres arranged in a fcc lattice, beyond the long-wavelength effective-medium description, is presented. Calculated transmission and absorption spectra of finite slabs of these materials are analyzed by reference to the acoustic modes of the constituent porous spherical grains as well as to relevant dispersion diagrams of corresponding infinite crystals, and a consistent interpretation of the results is provided. In particular, it is shown that resonant modes with very long lifetime, localized in the spheres in the form of slow longitudinal waves, which are peculiar to poroelastic materials, are formed when the viscous length is much shorter than the radius of the inner pores of the spheres. These modes, which can be easily tuned in frequency by adjusting the intrinsic porosity of the spheres, induce some remarkable features in the acoustic behavior of these double-porosity materials, such as narrow dispersionless absorption bands and directional transmission gaps.

  2. The Albedo of Pervious Cement Concrete Linearly Decreases with Porosity

    Directory of Open Access Journals (Sweden)

    Rui Zhang

    2015-01-01

    Full Text Available Pervious pavements have been advocated as a potential countermeasure to the urban heat island effect. To understand if pervious pavements stay cooler than conventional pavements, the albedo of the pervious concrete must be understood. This study measured the albedo of pervious concrete with different porosity. Four Portland cement concrete mixes were casted, using designed amounts of sand to vary the porosity of the pervious concrete samples. The samples were sliced and the spectral reflectance and albedo of the sliced samples were measured and analyzed. It is found that the albedo of pervious concrete decreases linearly with the increase of the porosity. The albedo of a pervious Portland concrete varies from 0.25 to 0.35, which is 0.05~0.15 lower than the albedo of conventional cement concrete. Due to this lower albedo, it should be cautious to develop pervious concrete to battle with urban heat island unless the evaporation of pervious concrete is promoted to compensate the additional solar absorption caused by the low albedo.

  3. Compost addition reduces porosity and chlordecone transfer in soil microstructure.

    Science.gov (United States)

    Woignier, Thierry; Clostre, Florence; Fernandes, Paula; Rangon, Luc; Soler, Alain; Lesueur-Jannoyer, Magalie

    2016-01-01

    Chlordecone, an organochlorine insecticide, pollutes soils and contaminates crops and water resources and is biomagnified by food chains. As chlordecone is partly trapped in the soil, one possible alternative to decontamination may be to increase its containment in the soil, thereby reducing its diffusion into the environment. Containing the pesticide in the soil could be achieved by adding compost because the pollutant has an affinity for organic matter. We hypothesized that adding compost would also change soil porosity, as well as transport and containment of the pesticide. We measured the pore features and studied the nanoscale structure to assess the effect of adding compost on soil microstructure. We simulated changes in the transport properties (hydraulic conductivity and diffusion) associated with changes in porosity. During compost incubation, the clay microstructure collapsed due to capillary stresses. Simulated data showed that the hydraulic conductivity and diffusion coefficient were reduced by 95 and 70% in the clay microstructure, respectively. Reduced transport properties affected pesticide mobility and thus helped reduce its transfer from the soil to water and to the crop. We propose that the containment effect is due not only to the high affinity of chlordecone for soil organic matter but also to a trapping mechanism in the soil porosity.

  4. A functionally gradient variational porosity architecture for hollowed scaffolds fabrication.

    Science.gov (United States)

    Khoda, A K M; Ozbolat, Ibrahim T; Koc, Bahattin

    2011-09-01

    This paper presents a novel continuous tool-path planning methodology for hollowed scaffold fabrication in tissue engineering. A new functionally gradient porous architecture is proposed with a continuous material deposition planning scheme. A controllable variational pore size and hence the porosity have been achieved with a combination of two geometrically oriented consecutive layers. The desired porosity has been achieved with consecutive layers by geometrically partitioning each layer into sub-regions based on the area and the tissue scaffold design constraints. A continuous, interconnected and optimized tool-path for layers has been generated for a three-dimensional biomaterial deposition/printing process. A zigzag pattern tool-path has been proposed for an accumulated sub-region layer, and a concentric spiral-like optimal tool-path pattern has been generated for the successive layer to ensure continuity along the structure. Three-dimensional layers, formed by the proposed tool-path plan, vary the pore size and the porosity based on the biological and mechanical requirements. Several examples demonstrate the proposed methodology along with illustrative results. Also a comparative study between the proposed design and conventional Cartesian coordinate scaffolds has been performed. The results demonstrate a significant reduction in design error with the proposed method. Moreover, sample examples have been fabricated using a micro-nozzle biomaterial deposition system, and characterized for validation.

  5. Porosity Defect Remodeling and Tensile Analysis of Cast Steel

    Directory of Open Access Journals (Sweden)

    Linfeng Sun

    2016-02-01

    Full Text Available Tensile properties on ASTM A216 WCB cast steel with centerline porosity defect were studied with radiographic mapping and finite element remodeling technique. Non-linear elastic and plastic behaviors dependent on porosity were mathematically described by relevant equation sets. According to the ASTM E8 tensile test standard, matrix and defect specimens were machined into two categories by two types of height. After applying radiographic inspection, defect morphologies were mapped to the mid-sections of the finite element models and the porosity fraction fields had been generated with interpolation method. ABAQUS input parameters were confirmed by trial simulations to the matrix specimen and comparison with experimental outcomes. Fine agreements of the result curves between simulations and experiments could be observed, and predicted positions of the tensile fracture were found to be in accordance with the tests. Chord modulus was used to obtain the equivalent elastic stiffness because of the non-linear features. The results showed that elongation was the most influenced term to the defect cast steel, compared with elastic stiffness and yield stress. Additional visual explanations on the tensile fracture caused by void propagation were also given by the result contours at different mechanical stages, including distributions of Mises stress and plastic strain.

  6. A functionally gradient variational porosity architecture for hollowed scaffolds fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Khoda, A K M [Department of Industrial Engineering, University at Buffalo, Buffalo, NY 14260 (United States); Ozbolat, Ibrahim T [Department of Mechanical and Industrial Engineering, Center for Computer Aided Design, University of Iowa, Iowa City, IA 52242-1527 (United States); Koc, Bahattin, E-mail: bahattinkoc@sabanciuniv.edu [Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul 34956 (Turkey)

    2011-09-15

    This paper presents a novel continuous tool-path planning methodology for hollowed scaffold fabrication in tissue engineering. A new functionally gradient porous architecture is proposed with a continuous material deposition planning scheme. A controllable variational pore size and hence the porosity have been achieved with a combination of two geometrically oriented consecutive layers. The desired porosity has been achieved with consecutive layers by geometrically partitioning each layer into sub-regions based on the area and the tissue scaffold design constraints. A continuous, interconnected and optimized tool-path for layers has been generated for a three-dimensional biomaterial deposition/printing process. A zigzag pattern tool-path has been proposed for an accumulated sub-region layer, and a concentric spiral-like optimal tool-path pattern has been generated for the successive layer to ensure continuity along the structure. Three-dimensional layers, formed by the proposed tool-path plan, vary the pore size and the porosity based on the biological and mechanical requirements. Several examples demonstrate the proposed methodology along with illustrative results. Also a comparative study between the proposed design and conventional Cartesian coordinate scaffolds has been performed. The results demonstrate a significant reduction in design error with the proposed method. Moreover, sample examples have been fabricated using a micro-nozzle biomaterial deposition system, and characterized for validation.

  7. High temperature furnace for nuclear magnetic resonance experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jaeger, C.; Scheler, G. (Friedrich-Schiller-Universitaet, Jena (German Democratic Republic). Sektion Physik)

    1984-01-01

    A furnace is described for NMR experiments in the temperature range 300 to 1,100 K. It can be used both in a superconducting solenoid (Oxford Instruments, B/sub 0/ = 6.4 T, bore 52 mm) and in iron magnets with a gap d >= 48 mm. All for NMR experiments important nuclei can be measured without /sup 29/Si. The NMR probe can be used both for instationary and stationary experiments.

  8. Soil Stabilisation Using Ground Granulated Blast Furnace Slag

    OpenAIRE

    Ashish Kumar Pathak; Dr. V. Pandey

    2014-01-01

    Stabilisation is a broad sense for the various methods employed and modifying the properties of a soil to improve its engineering performance and used for a variety of engineering works. In today‟s day soil stabilisation is the major problem for civil engineers, either for construction of road and also for increasing the strength or stability of soil and reduces the construction cost. In this thesis the soil are stabilised by ground granulated blast furnace slag (GGBS) and this material is ob...

  9. Demonstration and testing of high performance slot furnace. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bjerklie, J.W.; LaHaye, P.G.

    1978-04-01

    A demonstration and test program was conducted on a high temperature, 108'' slot, forge furnace. The efficacy of slot closures, medium weight insulation, massive-recirculation burners, temperature and O/sub 2/ controls, and ceramic recuperators was determined and compared to an unimproved furnace. Fired with No. 2 fuel oil at a maximum rate of 35 gph at start-up, the furnace was loaded manually employing 2/sup 1///sub 2/'' dia by 24'' long, round stock to simulate a typical forge shop load. Under these conditions, the furnace, with all improvements operative, achieved a steady state specific heat consumption (SHC) value of 850 Btu/lb of steel processed at an operating set point of 2400/sup 0/F and a steel processing rate of 3000 lbs/h. The value of each energy conserving improvement individually was determined and demonstrated. The largest single improvement was due to the ceramic recuperator (38%), followed by the door closures (11%), the massive-recirculation burners (10 to 20%), and improved wall thermal insulation (4%). The controls with the burner allowed essentially smoke-free operation to excess air levels of less than 5%. The economic impact of incorporating the energy-conserving recommendations of this study, using the industry ''norms'' for a conventionally equipped forge shop, was determined. Referred to the financial ''operating statement'', the improvement realized in the before-tax income of the forge shop would be increased approximately 20% assuming a current level of 10% profit before taxes.

  10. Blast furnace coke substitutes from Victorian brown coal

    OpenAIRE

    Mollah, Mamun

    2017-01-01

    Iron is usually produced from its ores using coke in a blast furnace (BF). Coke, a hard and macroporous carbon material, is produced from special coals (coking coals) and acts as fuel, smelting agent, and the permeable support for the charge to the BF. No material can completely replace coke in a BF. Coking coals are becoming harder (and more expensive) to obtain. Victorian brown coal (VBC) is accessible, cheap, with low mineral concentrations, which is favourable for iron production in a BF....

  11. Detailed model for practical pulverized coal furnaces and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, P.J.; Smoot, L.D.

    1989-08-01

    This study has been supported by a consortium of nine industrial and governmental sponsors. Work was initiated on May 1, 1985 and completed August 31, 1989. The central objective of this work was to develop, evaluate and apply a practical combustion model for utility boilers, industrial furnaces and gasifiers. Key accomplishments have included: Development of an advanced first-generation, computer model for combustion in three dimensional furnaces; development of a new first generation fouling and slagging submodel; detailed evaluation of an existing NO{sub x} submodel; development and evaluation of an improved radiation submodel; preparation and distribution of a three-volume final report: (a) Volume 1: General Technical Report; (b) Volume 2: PCGC-3 User's Manual; (c) Volume 3: Data Book for Evaluation of Three-Dimensional Combustion Models; and organization of a user's workshop on the three-dimensional code. The furnace computer model developed under this study requires further development before it can be applied generally to all applications; however, it can be used now by specialists for many specific applications, including non-combusting systems and combusting geseous systems. A new combustion center was organized and work was initiated to continue the important research effort initiated by this study. 212 refs., 72 figs., 38 tabs.

  12. 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.

  13. ADDITION OF ELECTRIC ARC FURNACE DUST IN HOT METAL

    Directory of Open Access Journals (Sweden)

    Felipe Fardin Grillo

    2013-03-01

    Full Text Available This research aims to study the process of incorporation of the mass in final hot metal and volatilization mass contained in the electric arc furnace dust (EAFD, by addition in hot metal at a temperature of 1,400°C; 1,450°C and 1,500°C altering experimental conditions such as the percentage of EAFD to be added and the percentage of silicon in hot metal. Previously, the EAFD was characterized using techniques of chemical analysis and size analysis. After characterization, the EAFD to be added to the hot metal was agglomerated in the form of briquettes. The achievement of fusion experiments in laboratory scale was placed in a vertical tubular furnace with temperature control. A flow of inert gas (argon was maintained inside the furnace during the experiments. The result of the sample EAFD volatilized shows that there is an increase in the zinc concentration when compared with the concentration of zinc present in EAFD “as received”.

  14. TECHNOLOGICAL FACTORS THAT CAUSED UNUSUAL DETERIORATION IN FURNACE TUBES

    Directory of Open Access Journals (Sweden)

    Nelson Felipe Llovet de Armas

    2017-04-01

    Full Text Available A refinery furnace used for heating crude oil showed abundant pelicules with unusual thicknesses in some pipes located in the convection zone, next to the wall of the furnace. The purpose of this research consisted in identifying the type of corrosion and determine the causes that originated the formation of the unusual pelicules. With the objective of elucidating which technological factors propitiated this deterioration, a visual inspection of the furnace was carried out to evaluate its structural state. From the values reported as thermocouples, temperature profiles of operation in the convection zone were obtained. The pelicules obtained were characterized using the X-ray diffraction technique and a metallographic microscope of reflected light. The results showed several deposits among the convection tubes; which cannot be eliminated because there isn't an adequate system of removal. This problem is accentuated by the substitution of old refractory bricks by modern monolithic panels. Such situation favored the formation of canalizations or preferential zones that propitiated the increase of the velocity of gases to high temperature and a rise of the concentration of O2 on low alloy steel pipes. These factors caused an anomalous behavior of the temperatures of operation and the formation of pelicules of mill scale type, of macrocrystalline structures, constituted for few adherent iron oxides and unusual thicknesses. These results show a severe oxidation in high temperatures.

  15. THE EFFECT OF POROSITY ON THE STRUCTURE AND PROPERTIES OF CALCIUM POLYPHOSPHATE BIOCERAMICS

    Directory of Open Access Journals (Sweden)

    CHANGXIU WAN

    2011-03-01

    Full Text Available Calcium polyphosphate (CPP bioceramic with different porosities were prepared by controlling the concentration of the pore-foaming agent. Effect of porosity (0%, 15%, 30%, 45% and 60% on the microstructure, pores interconnection, dissolution behavior and compressive strength of CPP bioceramic were investigated. Scanning electron microscope (SEM and capillarity test results indicated that CPP with higher porosity (45% and 60% exhibited three-dimensional interconnected pore structure with a pore size of about 200–400 μm, while the pores of lower porosity scaffold (0%, 15% and 30% were isolated. The dissolution behavior in vitro indicated that the dissolution rate accelerated with the porosity increasing and the CPP with 60% porosity showed the highest dissolution velocity. The compressive strength of porosity CPP scaffolds were as much as the human cancellous bone, which decreased with the increase of porosity. While the dense CPP scaffolds lie in the same order of magnitude as compact bone.

  16. 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.

  17. Improved dual-porosity models for petrophysical analysis of vuggy reservoirs

    Science.gov (United States)

    Wang, Haitao

    2017-08-01

    A new vug interconnection, isolated vug (IVG), was investigated through resistivity modeling and the dual-porosity model for connected vug (CVG) vuggy reservoirs was tested. The vuggy models were built by pore-scale modeling, and their electrical resistivity was calculated by the finite difference method. For CVG vuggy reservoirs, the CVG reduced formation factors and increased the porosity exponents, and the existing dual-porosity model failed to match these results. Based on the existing dual-porosity model, a conceptual dual-porosity model for CVG was developed by introducing a decoupled term to reduce the resistivity of the model. For IVG vuggy reservoirs, IVG increased the formation factors and porosity exponents. The existing dual-porosity model succeeded due to accurate calculation of the formation factors of the deformed interparticle porous media caused by the insertion of the IVG. Based on the existing dual-porosity model, a new porosity model for IVG vuggy reservoirs was developed by simultaneously recalculating the formation factors of the altered interparticle pore-scale models. The formation factors and porosity exponents from the improved and extended dual-porosity models for CVG and IVG vuggy reservoirs well matched the simulated formation factors and porosity exponents. This work is helpful for understanding the influence of connected and disconnected vugs on resistivity factors—an issue of particular importance in carbonates.

  18. Drying shrinkage of mortars with limestone filler and blast-furnace slag

    Directory of Open Access Journals (Sweden)

    Carrasco, M. F.

    2003-12-01

    Full Text Available During the 1990's the use of cements made with port land clinker and two mineral admixtures, called ternary or blended cements, has grown considerably. Nowadays, cements containing several combinations of fly ash and silica fume, blast-furnace slag and silica fume or blast-furnace slag and limestone filler are commonly used. There are numerous works on the influence of blended cements on the fresh state and mechanical properties of mortar and concrete, but the their deformations due to drying shrinkage are not so well described. Analysis of drying shrinkage is relevant because this property influences the possibility of cracking occurrence and, hence, the deterioration of mechanical and durable properties of concrete structures. This paper evaluates the influence on the drying shrinkage of mortars of variable contents of limestone filler and/or blast-furnace slag in Portland cement. Additionally, flexion strength and non evaporable water content were evaluated. Test results show that the inclusion of these mineral admixtures, Joint or separately, increments drying shrinkage of mortars at early ages. Despite this fact, mortars made with limestone filler cement are less susceptible to cracking than mortars made with cements incorporating blast-furnace slag or both admixtures.

    Durante los años 90 el uso de cementos fabricados con clínker Portland y dos adiciones suplementarias (cementos ternarios o compuestos se ha incrementado en forma considerable. En la práctica, es cada vez más común el empleo de estos cementos conteniendo combinaciones de ceniza volante y humo de sílice, escoria y humo de sílice o escoria y filler calcáreo. En la actualidad existen numerosos estudios sobre la influencia de los cementos compuestos en las características en estado fresco y las propiedades mecánicas de morteros y hormigones, pero las deformaciones que estos materiales sufren debido a la retracción por secado no son tan conocidas. El análisis de

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

    Directory of Open Access Journals (Sweden)

    S.. V. Korneev

    2014-01-01

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

  20. Condensation Enhancement by Surface Porosity: Three-Stage Mechanism.

    Science.gov (United States)

    Yarom, Michal; Marmur, Abraham

    2015-08-18

    Surface defects, such as pores, cracks, and scratches, are naturally occurring and commonly found on solid surfaces. However, the mechanism by which such imperfections promote condensation has not been fully explored. In the current paper we thermodynamically analyze the ability of surface porosity to enhance condensation on a hydrophilic solid. We show that the presence of a surface-embedded pore brings about three distinct stages of condensation. The first is capillary condensation inside the pore until it is full. This provides an ideal hydrophilic surface for continuing the condensation. As a result, spontaneous condensation and wetting can be achieved at lower vapor pressure than on a smooth surface.

  1. Blast furnace coke properties and the influence on off-gas dust

    OpenAIRE

    Lundgren, Maria

    2010-01-01

    In blast furnace ironmaking, efforts are made to decrease the coke consumption mainly by increasing the pulverized coal injection rate. This will cause changes in in-furnace reduction conditions, burden distribution and demands on raw material strength, etc. In order to maintain stable operation and minimize material losses through the off-gas, it is important to understand fines generation and behaviour in the blast furnace.  The strength and reactivity of coke at high temperature, measured ...

  2. Precision control of high temperature furnaces using an auxiliary power supply and charged practice current flow

    Science.gov (United States)

    Pollock, George G.

    1997-01-01

    Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved.

  3. Precision control of high temperature furnaces using an auxiliary power supply and charged particle current flow

    Science.gov (United States)

    Pollock, G.G.

    1997-01-28

    Two power supplies are combined to control a furnace. A main power supply heats the furnace in the traditional manner, while the power from the auxiliary supply is introduced as a current flow through charged particles existing due to ionized gas or thermionic emission. The main power supply provides the bulk heating power and the auxiliary supply provides a precise and fast power source such that the precision of the total power delivered to the furnace is improved. 5 figs.

  4. Optimized Choice for Pollution Control Systems in Smelting Furnaces with Green Approach

    OpenAIRE

    Parviz Jafari-Fesharaki; Elham Ghazanchaei; Beheshteh Jebelli

    2015-01-01

     Furnace division is one of the most polluted divisions ever known in the steel industry associated with several environmental pollutions. This study attempted to choose optimally, a pollution control system for dust emission from steel furnaces with the Green and environmentally friendly approach. Three electric smelting furnaces with 3, 6 and 12-ton output capacity were selected. The level of energy cost and consumption, capital and environmental damage, and indexes of environmental sustain...

  5. Thermal Oxidation of Tail Gases from the Production of Oil-furnace Carbon Black

    OpenAIRE

    Bosak, Z.; Barta, D.; Zečević, N.; S. Šiklušić

    2009-01-01

    This paper describes the production technology of oil-furnace carbon black, as well as the selected solution for preventing the emissions of this process from contaminating the environment.The products of industrial oil-furnace carbon black production are different grades of carbon black and process tail gases. The qualitative composition of these tail gases during the production of oil-furnace carbon black are: carbon(IV) oxide, carbon(II) oxide, hydrogen, methane, hydrogen sulfide, nitrogen...

  6. Development of charge calculation program for target steel in induction furnace

    OpenAIRE

    Saliu O. SEIDU; Adetunji ONIGBAJUMO

    2015-01-01

    This paper presents the development of charge calculation program for target steel in induction furnace. The simulation modelling function developed is based on mass balance analysis of the furnace production. The process engineering of the furnace follows linear algebraic mathematical function. Visual basic programming language (C#) is used in the coding and interface integration. This is used to develop a unit process based simulation program with user friendly interface f...

  7. Effect of Amount of Carbon on the Reduction Efficiency of Iron Ore-Coal Composite Pellets in Multi-layer Bed Rotary Hearth Furnace (RHF)

    Science.gov (United States)

    Mishra, Srinibash; Roy, Gour Gopal

    2016-08-01

    The effect of carbon-to-hematite molar ratio has been studied on the reduction efficiency of iron ore-coal composite pellet reduced at 1523 K (1250 °C) for 20 minutes in a laboratory scale multi-layer bed rotary hearth furnace (RHF). Reduced pellets have been characterized through weight loss measurement, estimation of porosity, shrinkage, qualitative and quantitative phase analysis by XRD. Performance parameters such as the degree of reduction, metallization, carbon efficiency, productivity, and compressive strength have been calculated to compare the process efficacy at different carbon levels in the pellets. Pellets with optimum carbon-to-hematite ratio (C/Fe2O3 molar ratio = 1.66) that is much below the stoichiometric carbon required for direct reduction of hematite yielded maximum reduction, better carbon utilization, and productivity for all three layers. Top layer exhibited maximum reduction at comparatively lower carbon level (C/Fe2O3 molar ratio 2.33). Correlation between degree of reduction and metallization indicated non-isothermal kinetics influenced by heat and mass transfer in multi-layer bed RHF. Compressive strength of the partially reduced pellet with optimum carbon content (C/Fe2O3 molar ratio = 1.66) showed that they could be potentially used as an alternate feed in a blast furnace or any other smelting reactor.

  8. Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high temperature furnace (HITAF)

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    A concept for an advanced coal-fired combined-cycle power generating system is currently being developed. The first phase of this three-phase program consists of conducting the necessary research and development to define the system, evaluate the economic and technical feasibility of the concept, and prepare an R D plan to develop the concept further. Foster Wheeler Development Corporation is leading a team ofcompanies involved in this effort. The system proposed to meet these goals is a combined-cycle system where air for a gas turbine is indirectly heated to approximately 1800[degrees]F in furnaces fired with cool-derived fuels and then directly heated in a natural-gas-fired combustor up to about 2400[degrees]F. The system is based on a pyrolyzing process that converts the coal into a low-Btu fuel gas and char. The fuelgas is a relatively clean fuel, and it is fired to heat tube surfaces that are susceptible to corrosion and problems from ash deposition. In particular, the high-temperature air heater tubes, which will need tobe a ceramic material, will be located in a separate furnace or region of a furnace that is exposed to combustion products from the low-Btu fuel gas only. A simplified process flow diagram is shown.

  9. Hydrodynamics in a circulating fluidized bed with annular furnace and six parallel cyclones

    Science.gov (United States)

    Shuai, Daping; Wang, Xiaofang; Lyu, Qinggang

    2017-06-01

    Systematic measurements were conducted on a cold CFB with annular furnace and six parallel cyclones to study gas-solids flow in the annular furnace and flow non-uniformity among six cyclones. The results show that axial solids holdup in the annular furnace decreases exponentially with height, similar to the conventional rectangular furnace. The uniform transverse distribution of solids holdup suggests a good gas-solids mixing in the annular furnace. The annular furnace presents the core/double-annulus flow structure, and it results in enhanced gas-solids back-mixing than the conventional core/annulus flow structure. The gas-solids flow of the inner wall-layer and the outer wall-layer is very close at most part of the furnace height, and the wall-layer thickness decreases with height. Flow non-uniformity exists among six parallel cyclones in the annular furnace CFB. But non-uniform distribution of solids circulating rates and cyclone pressure drops show no regularity, and the flow non-uniformity is no larger than the CFBs with conventional furnace. Under typical operating conditions, the relative deviation of six solids circulating rates is 8.0%.

  10. Modeling energy consumption of residential furnaces and boilers in U.S. homes

    Energy Technology Data Exchange (ETDEWEB)

    Lutz, James; Dunham-Whitehead, Camilla; Lekov, Alex; McMahon, James

    2004-02-01

    In 2001, DOE initiated a rulemaking process to consider whether to amend the existing energy efficiency standards for furnaces and boilers. A key factor in DOE's consideration of new standards is their cost-effectiveness to consumers. Determining cost-effectiveness requires an appropriate comparison of the additional first cost of energy efficiency design options with the savings in operating costs. This report describes calculation of equipment energy consumption (fuel and electricity) based on estimated conditions in a sample of homes that are representative of expected furnace and boiler installations. To represent actual houses with furnaces and boilers in the United States, we used a set of houses from the Residential Energy Consumption Survey of 1997 conducted by the Energy Information Administration. Our calculation methodology estimates the energy consumption of alternative (more-efficient) furnaces, if they were to be used in each house in place of the existing equipment. We developed the method of calculation described in this report for non-weatherized gas furnaces. We generalized the energy consumption calculation for this product class to the other furnace product classes. Fuel consumption calculations for boilers are similar to those for the other furnace product classes. The electricity calculations for boilers are simpler than for furnaces, because boilers do not provide thermal distribution for space cooling as furnaces often do.

  11. Acid slag injection into the blast furnace tuyere zone

    Energy Technology Data Exchange (ETDEWEB)

    Haerkki, J.; Tervola, K. [Oulu Univ. (Finland). Dept. of Process Engineering

    1996-12-31

    The possibility of acid slag injection and its effect on the slag formation and on the melting behaviour of the charge materials are studied in the present work. The work is partly based on the literature evaluating the slag formation, slag properties and the basic slag injection. The possibility of acid slag injection is first examined by studying changes in the composition of the primary slag if the share of the acid slag component (Kostamus pellet/RR) of the charge material is lowered. Phase diagrams and viscosity charts are used to evaluate the viscosity, and solidus/liquidus temperature in the slag phase. The share of the slag phase of the pellet is evaluated by calculating the amount of the acid slag injection. The injection rate of some injectants is also examined. The primary slag formed of the sinter and the coke ash is in liquid form and its viscosity is close to the viscosity of the blast furnace slag. It is possible that the liquid slag phase can be formed in the blast furnace without the presence of the acid pellet because the melting point and the viscosity of the slag is lowered by alkalies, sulfur and the dissolved ironoxide of the slag. If high SiO{sub 2} content materials alone are used for injection there is a risk that the slag phase of the tuyere zone becomes too viscous. Olivine and some iron containing components such as fayalite are possible injection material. More information is needed to evaluate the effect of acid slag injection on the operation of the blast furnace. (orig.) SULA 2 Research Programme; 2 refs.

  12. New PSA high concentration solar furnace SF40

    Science.gov (United States)

    Rodriguez, Jose; Cañadas, Inmaculada; Zarza, Eduardo

    2016-05-01

    A new solar furnace has been designed and built at Plataforma Solar de Almería. In this work, its main components such as heliostat, concentrator, attenuator and test table, and the method used to align them are described. Other equipment like the auxiliary systems necessary for the solar operation, vacuum chamber and gas system are outlined too. Finally, the thermal characteristics of the focus were measured during a test campaign, where different planes along the optical axis were scanned with a radiometer, and the peak flux was obtained and is presented in the last section of this report.

  13. Evolution of coke properties while descending through a blast furnace

    OpenAIRE

    Hilding, Tobias

    2005-01-01

    Due to increasing price and economic pressures, there is a need to minimise coke consumption. The lesser amount of coke used has indirectly set higher standards for coke quality and led to a wish for even more knowledge about its function in the blast furnace. Over the last 20 years, coke quality has been strongly dictated by the so- called CSR value because it was believed that a higher CSR leads to improvement in productivity and more stable operation. Due to lack of suitable coals, often c...

  14. Improving the Quality of Electric Energy to Electric Arc Furnace

    Directory of Open Access Journals (Sweden)

    Adrian-Ioan Toma

    2011-10-01

    Full Text Available This paper presents a study of power quality problems created by an electric arc furnace (EAF with eccentric bottom tap (EBT at power system. The analysis have been done to EAF of 100 t capacity used for steel melting. Experimental results show this EAF is substantial source of electric disturbances, such as voltage fluctuations, flicker, harmonics, and unbalance between phases. Improvement of the quality of electric energy at EAF imposes a careful technical and economical analysis. Of all possible solutions for improvement of the power quality for an EAF (passive filter, STATCOM or SVC, SVC is the ideal solution.

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

    OpenAIRE

    Deng, Lei

    2012-01-01

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

  16. A study of slag freezing in metallurgical furnaces

    Science.gov (United States)

    Guevara, Fernando

    Many smelting and slag-cleaning furnaces operate with cooling systems designed to freeze a slag layer over the refractory to protect it. The fluid flow and heat transfer conditions associated with the freeze layer and mushy zones are poorly understood. This study was conducted to understand the chill layer formation and heat transfer that is required to design cooling systems in pyrometallurgical operations where a slag layer is required to protect the furnace wall. The freeze layer formation and heat transfer in mushy zones were experimentally study at room temperature in a 2-dimensional square cavity differentially heated, using an aqueous solution of calcium chloride to simulate the slag. Reasonable similarity with conditions encountered with copper and nickel smelting systems was achieved (Pr ≈ 50 and Ra ≈ 108, in the laminar-turbulent transition). Measurements of velocities were made with the Particle Image Velocimetry (PIV) technique. The freeze layer development was tracked using a digital camera. Direct Numerical Simulations (DNS) of the mean flow using a finite control volume technique with a fixed domain method were also made of the unsteady fluid flow and heat transfer problem. It was found that the macro solidification process is well described using an improved model for high molecular viscosity in the mushy zone. Solid front growth, isothermal profiles, velocity profiles and heat transfer through the walls showed good agreement between the PIV and DNS results. Experimental and numerical velocity profiles close to the freeze layer show a parabolic behaviour in the vertical velocity profile which is completely different from the calculation of heat transfer using a sharp interface model. The reason for this is attributed to the effects of the mushy zone with a high viscosity and high shear stresses acting on that area. In Part III of this Thesis, effects of slag viscosity temperature relationship were analysed with a two-dimensional mathematical

  17. Effect of shelter porosity on downwind flow characteristics

    Science.gov (United States)

    Nosek, Š.; Kellnerová, R.; Jurčáková, K.; Jaňour, Z.; Chaloupecká, H.; Jakubcová, M.

    2016-03-01

    Previous wind-tunnel studies were focused mainly on lonely standing windbreaks or wind fences with respect to their wind velocity reduction efficiency and effective shelter distance. In presented wind-tunnel study, we investigated the effects of a three different fence porosities (0.5, 0.25 and 0) embodied in a shelter-like building for coal convey by means of two-component Laser Doppler Anemometry (LDA). The turbulent flow characteristics behind the fences were compared with those performed without the fence. For characterization of the fence effectiveness we used following quantities: wind-speed and turbulence kinetic energy reduction, and time fractions of the turbulent coherent structures associated with the sediment transport (sweeps and outward interactions). Results from mentioned quantities revealed that for the case of embodied fence the shelter construction has significant impact on the flow characteristics behind. The fence of the 0.5 porosity has been indicated as the most shelter effective considering the studied quantities.

  18. A comparison of estimated and calculated effective porosity

    Science.gov (United States)

    Stephens, Daniel B.; Hsu, Kuo-Chin; Prieksat, Mark A.; Ankeny, Mark D.; Blandford, Neil; Roth, Tracy L.; Kelsey, James A.; Whitworth, Julia R.

    Effective porosity in solute-transport analyses is usually estimated rather than calculated from tracer tests in the field or laboratory. Calculated values of effective porosity in the laboratory on three different textured samples were compared to estimates derived from particle-size distributions and soil-water characteristic curves. The agreement was poor and it seems that no clear relationships exist between effective porosity calculated from laboratory tracer tests and effective porosity estimated from particle-size distributions and soil-water characteristic curves. A field tracer test in a sand-and-gravel aquifer produced a calculated effective porosity of approximately 0.17. By comparison, estimates of effective porosity from textural data, moisture retention, and published values were approximately 50-90% greater than the field calibrated value. Thus, estimation of effective porosity for chemical transport is highly dependent on the chosen transport model and is best obtained by laboratory or field tracer tests. Résumé La porosité effective dans les analyses de transport de soluté est habituellement estimée, plutôt que calculée à partir d'expériences de traçage sur le terrain ou au laboratoire. Les valeurs calculées de la porosité effective au laboratoire sur trois échantillons de textures différentes ont été comparées aux estimations provenant de distributions de taille de particules et de courbes caractéristiques sol-eau. La concordance était plutôt faible et il semble qu'il n'existe aucune relation claire entre la porosité effective calculée à partir des expériences de traçage au laboratoire et la porosité effective estimée à partir des distributions de taille de particules et de courbes caractéristiques sol-eau. Une expérience de traçage de terrain dans un aquifère de sables et de graviers a fourni une porosité effective calculée d'environ 0,17. En comparaison, les estimations de porosité effective de données de

  19. Ferromanganese Furnace Modelling Using Object-Oriented Principles

    Energy Technology Data Exchange (ETDEWEB)

    Wasboe, S.O.

    1996-12-31

    This doctoral thesis defines an object-oriented framework for aiding unit process modelling and applies it to model high-carbon ferromanganese furnaces. A framework is proposed for aiding modelling of the internal topology and the phenomena taking place inside unit processes. Complex unit processes may consist of a number of zones where different phenomena take place. A topology is therefore defined for the unit process itself, which shows the relations between the zones. Inside each zone there is a set of chemical species and phenomena, such as reactions, phase transitions, heat transfer etc. A formalized graphical methodology is developed as a tool for modelling these zones and their interaction. The symbols defined in the graphical framework are associated with objects and classes. The rules for linking the objects are described using OMT (Object Modeling Technique) diagrams and formal language formulations. The basic classes that are defined are implemented using the C++ programming language. The ferromanganese process is a complex unit process. A general description of the process equipment is given, and a detailed discussion of the process itself and a system theoretical overview of it. The object-oriented framework is then used to develop a dynamic model based on mass and energy balances. The model is validated by measurements from an industrial furnace. 101 refs., 119 figs., 20 tabs.

  20. Self-calibrated active pyrometer for furnace temperature measurements

    Science.gov (United States)

    Woskov, Paul P.; Cohn, Daniel R.; Titus, Charles H.; Surma, Jeffrey E.

    1998-01-01

    Pyrometer with a probe beam superimposed on its field-of-view for furnace temperature measurements. The pyrometer includes a heterodyne millimeter/sub-millimeter-wave or microwave receiver including a millimeter/sub-millimeter-wave or microwave source for probing. The receiver is adapted to receive radiation from a surface whose temperature is to be measured. The radiation includes a surface emission portion and a surface reflection portion which includes the probe beam energy reflected from the surface. The surface emission portion is related to the surface temperature and the surface reflection portion is related to the emissivity of the surface. The simultaneous measurement of surface emissivity serves as a real time calibration of the temperature measurement. In an alternative embodiment, a translatable base plate and a visible laser beam allow slow mapping out of interference patterns and obtaining peak values therefor. The invention also includes a waveguide having a replaceable end portion, an insulating refractory sleeve and/or a source of inert gas flow. The pyrometer may be used in conjunction with a waveguide to form a system for temperature measurements in a furnace. The system may employ a chopper or alternatively, be constructed without a chopper. The system may also include an auxiliary reflector for surface emissivity measurements.

  1. Characterization study of electric arc furnace dust phases

    Directory of Open Access Journals (Sweden)

    Janaína Gonçalves Maria da Silva Machado

    2006-03-01

    Full Text Available Electric arc furnace dust (EAFD is a solid waste generated in the collection of particulate material during steelmaking process in electric arc furnace. The aim of this work is to carry out a chemical and structural characterization of two EAFD samples with different Zn contents. Optical emission spectroscopy via inductively coupled plasma (ICP, X ray diffractometry (XRD and Mössbauer spectroscopy analysis were carried out in such EAFD samples. From XRD measurements, the samples exhibits the following phases: ZnFe2O4, Fe3O4, MgFe2O4, FeCr2O4, Ca0.15Fe2.85O4, MgO, Mn3O4, SiO2 and ZnO. The phases detected by Mössbauer spectroscopy were: ZnFe2O4, Fe3O4, Ca0.15Fe2.85O4 and FeCr2O4. Magnesium ferrite (MgFe2O4, observed in the XRD patterns as overlapped peaks, was not identified in the Mössbauer spectroscopy analysis.

  2. Optimization for blast furnace slag dry cooling granulation device

    Science.gov (United States)

    Dazhan, Sheng; Yali, Wang; Ruiyun, Wang; Suping, Cui; Xiaoyu, Ma

    2017-03-01

    Since the large accumulation amount of blast furnace slag (BFS) with recycling value, it has become a hot topic for recovery utilization. Compared with the existing various BFS granulation process, the dry granulation process can promote the use of blast furnace granulated slag as cement substitute and concrete admixtures. Our research group developed a novel dry cooling granulation experiment device to treat BFS. However, there are still some problems to be solved. The purpose of this research is to improve the cooling and granulation efficiency of the existing dry type cooling equipment. This topic uses the FLUENT simulation software to study the impact of the number of air inlet on the cooling effect of the device. The simulation result is that the device possessing eight air inlets can increase the number of hot and cold gas exchanged, resulting in a better cooling effect. According to the power consumption, LCA analysis was carried out on the cooling granulation process. The results show that the device equipped eight air inlets not only improved the original equipment cooling granulation effect, but also increased resource utilization ratio, realized energy-saving and emission reduction.

  3. Acoustic methods for measuring the porosities of porous materials incorporating dead-end pores.

    Science.gov (United States)

    Dupont, Thomas; Leclaire, Philippe; Panneton, Raymond

    2013-04-01

    The acoustic properties of porous materials containing dead-end (DE) pores have been proposed by Dupont et al. [J. Appl. Phys. 110, 094903 (2011)]. In the theoretical description, two physical parameters were defined (the dead-end porosity and the average length of the dead-end pores). With the knowledge of the open porosity (measured with non-acoustic methods), and the measurement of kinematic porosity (also called the Biot porosity in this article), it is possible to deduce the dead-end porosity. Two acoustic methods for measuring the Biot porosity for a wide range of porosities are proposed. These methods are based on acoustic transmission and on the low and high frequency behaviors of acoustic indicators. The low frequency method is valid for high porosities. It involves measurements in a transmission tube and the knowledge of the theoretical asymptotic behavior of the phase velocity at high frequencies. The high frequency method is based on ultrasonic measurements and on the high frequency asymptotic behavior of the transmission coefficient. It is well adapted for material with relatively low values of porosity. Good precision was found for both methods and materials containing dead end porosity were tested.

  4. An Efficient Modelling Approach for Prediction of Porosity Severity in Composite Structures

    Science.gov (United States)

    Bedayat, Houman; Forghani, Alireza; Hickmott, Curtis; Roy, Martin; Palmieri, Frank; Grimsley, Brian; Coxon, Brian; Fernlund, Goran

    2017-01-01

    Porosity, as a manufacturing process-induced defect, highly affects the mechanical properties of cured composites. Multiple phenomena affect the formation of porosity during the cure process. Porosity sources include entrapped air, volatiles and off-gassing as well as bag and tool leaks. Porosity sinks are the mechanisms that contribute to reducing porosity, including gas transport, void shrinkage and collapse as well as resin flow into void space. Despite the significant progress in porosity research, the fundamentals of porosity in composites are not yet fully understood. The highly coupled multi-physics and multi-scale nature of porosity make it a complicated problem to predict. Experimental evidence shows that resin pressure history throughout the cure cycle plays an important role in the porosity of the cured part. Maintaining high resin pressure results in void shrinkage and collapse keeps volatiles in solution thus preventing off-gassing and bubble formation. This study summarizes the latest development of an efficient FE modeling framework to simulate the gas and resin transport mechanisms that are among the major phenomena contributing to porosity.

  5. Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs.

    Directory of Open Access Journals (Sweden)

    Kohei Tanaka

    Full Text Available Knowledge about the types of nests built by dinosaurs can provide insight into the evolution of nesting and reproductive behaviors among archosaurs. However, the low preservation potential of their nesting materials and nesting structures means that most information can only be gleaned indirectly through comparison with extant archosaurs. Two general nest types are recognized among living archosaurs: 1 covered nests, in which eggs are incubated while fully covered by nesting material (as in crocodylians and megapodes, and 2 open nests, in which eggs are exposed in the nest and brooded (as in most birds. Previously, dinosaur nest types had been inferred by estimating the water vapor conductance (i.e., diffusive capacity of their eggs, based on the premise that high conductance corresponds to covered nests and low conductance to open nests. However, a lack of statistical rigor and inconsistencies in this method render its application problematic and its validity questionable. As an alternative we propose a statistically rigorous approach to infer nest type based on large datasets of eggshell porosity and egg mass compiled for over 120 extant archosaur species and 29 archosaur extinct taxa/ootaxa. The presence of a strong correlation between eggshell porosity and nest type among extant archosaurs indicates that eggshell porosity can be used as a proxy for nest type, and thus discriminant analyses can help predict nest type in extinct taxa. Our results suggest that: 1 covered nests are likely the primitive condition for dinosaurs (and probably archosaurs, and 2 open nests first evolved among non-avian theropods more derived than Lourinhanosaurus and were likely widespread in non-avian maniraptorans, well before the appearance of birds. Although taphonomic evidence suggests that basal open nesters (i.e., oviraptorosaurs and troodontids were potentially the first dinosaurs to brood their clutches, they still partially buried their eggs in sediment

  6. Eggshell Porosity Provides Insight on Evolution of Nesting in Dinosaurs.

    Science.gov (United States)

    Tanaka, Kohei; Zelenitsky, Darla K; Therrien, François

    2015-01-01

    Knowledge about the types of nests built by dinosaurs can provide insight into the evolution of nesting and reproductive behaviors among archosaurs. However, the low preservation potential of their nesting materials and nesting structures means that most information can only be gleaned indirectly through comparison with extant archosaurs. Two general nest types are recognized among living archosaurs: 1) covered nests, in which eggs are incubated while fully covered by nesting material (as in crocodylians and megapodes), and 2) open nests, in which eggs are exposed in the nest and brooded (as in most birds). Previously, dinosaur nest types had been inferred by estimating the water vapor conductance (i.e., diffusive capacity) of their eggs, based on the premise that high conductance corresponds to covered nests and low conductance to open nests. However, a lack of statistical rigor and inconsistencies in this method render its application problematic and its validity questionable. As an alternative we propose a statistically rigorous approach to infer nest type based on large datasets of eggshell porosity and egg mass compiled for over 120 extant archosaur species and 29 archosaur extinct taxa/ootaxa. The presence of a strong correlation between eggshell porosity and nest type among extant archosaurs indicates that eggshell porosity can be used as a proxy for nest type, and thus discriminant analyses can help predict nest type in extinct taxa. Our results suggest that: 1) covered nests are likely the primitive condition for dinosaurs (and probably archosaurs), and 2) open nests first evolved among non-avian theropods more derived than Lourinhanosaurus and were likely widespread in non-avian maniraptorans, well before the appearance of birds. Although taphonomic evidence suggests that basal open nesters (i.e., oviraptorosaurs and troodontids) were potentially the first dinosaurs to brood their clutches, they still partially buried their eggs in sediment. Open nests

  7. Improved Blackbody Temperature Sensors for a Vacuum Furnace

    Science.gov (United States)

    Farmer, Jeff; Coppens, Chris; O'Dell, J. Scott; McKechnie, Timothy N.; Schofield, Elizabeth

    2009-01-01

    Some improvements have been made in the design and fabrication of blackbody sensors (BBSs) used to measure the temperature of a heater core in a vacuum furnace. Each BBS consists of a ring of thermally conductive, high-melting-temperature material with two tantalum-sheathed thermocouples attached at diametrically opposite points. The name "blackbody sensor" reflects the basic principle of operation. Heat is transferred between the ring and the furnace heater core primarily by blackbody radiation, heat is conducted through the ring to the thermocouples, and the temperature of the ring (and, hence, the temperature of the heater core) is measured by use of the thermocouples. Two main requirements have guided the development of these BBSs: (1) The rings should have as high an emissivity as possible in order to maximize the heat-transfer rate and thereby maximize temperature-monitoring performance and (2) the thermocouples must be joined to the rings in such a way as to ensure long-term, reliable intimate thermal contact. The problem of fabricating a BBS to satisfy these requirements is complicated by an application-specific prohibition against overheating and thereby damaging nearby instrumentation leads through the use of conventional furnace brazing or any other technique that involves heating the entire BBS and its surroundings. The problem is further complicated by another application-specific prohibition against damaging the thin tantalum thermocouple sheaths through the use of conventional welding to join the thermocouples to the ring. The first BBS rings were made of graphite. The tantalum-sheathed thermocouples were attached to the graphite rings by use of high-temperature graphite cements. The ring/thermocouple bonds thus formed were found to be weak and unreliable, and so graphite rings and graphite cements were abandoned. Now, each BBS ring is made from one of two materials: either tantalum or a molybdenum/titanium/zirconium alloy. The tantalum

  8. Susceptibility to malignant hyperthermia

    NARCIS (Netherlands)

    Snoeck, Marcus Matheus Johannes

    2004-01-01

    In this thesis the author studied the diagnostic procedures for susceptibility to malignant hyperthermia (MH), with special emphasis upon refining the biological diagnostic test and improving protocols and guidelines for investigation of MH susceptibility. MH is a pharmacogenetic disease of skeletal

  9. Collection and conversion of silicon furnace waste gas into higher value products: Phase 3, 6 MW pilot plant dc closed furnace technology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Dosaj, V.D.

    1995-01-01

    The construction and operation of a 6 MW, closed dc furnace for smelting silicon was the primary focus of Phase 3. A 6 MW, dc closed furnace pilot plant was built in East Selkirk, Manitoba, Canada. The furnace is equipped with world`s most modern automatic control system used to control and monitor the process variables and operational data. This control system is suitable for commercial applications and could be used with either closed or open dc furnaces for smelting silicon or ferrosilicon. The construction was started in September 1990, and the facility was operational within 18 months. Following successful commissioning of the pilot plant in June 1992, twelve smelting test campaigns were conducted through November 1994.

  10. Spark plasma sintering and porosity studies of uranium nitride

    Science.gov (United States)

    Johnson, Kyle D.; Wallenius, Janne; Jolkkonen, Mikael; Claisse, Antoine

    2016-05-01

    In this study, a number of samples of UN sintered by the SPS method have been fabricated, and highly pure samples ranging in density from 68% to 99.8%TD - corresponding to an absolute density of 14.25 g/cm3 out of a theoretical density of 14.28 g/cm3 - have been fabricated. By careful adjustment of the sintering parameters of temperature and applied pressure, the production of pellets of specific porosity may now be achieved between these ranges. The pore closure behaviour of the material has also been documented and compared to previous studies of similar materials, which demonstrates that full pore closure using these methods occurs near 97.5% of relative density.

  11. Monolithic SiOC ceramics with tailored porosity

    Energy Technology Data Exchange (ETDEWEB)

    Berndt, F.; Jahn, P.; Motz, G.; Ziegler, G. [Bayreuth Univ. (Germany). Inst. for Materials Research; Rendtel, A. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Materialforschung

    2002-07-01

    Mixing two catalytically cross-linking liquid polysiloxanes leads to porous but crack-free bodies after pyrolysis at 1100 C in nitrogen. The low viscosity of the polysiloxanes allows the application of polymer-based moulding techniques like casting of complex-shaped SiOC components. Porosity and pore formation can be varied by changing the mixing ratio of the polysiloxanes. Pore formation affects strength, elastic modulus, fracture toughness, and creep behaviour. Four point bending strength varies between about 125 and 150 MPa (specimen size 3.5 x 3.0 x 50 mm{sup 3}). Analysis of fracture surfaces shows crack deflection at the pores leading to fracture toughness values of up to 2.0 MPa m{sup 1/2}. Investigation of the creep behaviour in compression revealed an improved creep resistance compared to silica glass depending on the thermal history of the amorphous material. (orig.)

  12. Controlling porosity in bridged polysilsesquioxanes through elimination reactions

    Energy Technology Data Exchange (ETDEWEB)

    McClain, M.D.; Loy, D.A. [Sandia National Labs., Albuquerque, NM (United States); Prabakar, S. [Univ. of New Mexico, Albuquerque, NM (United States). Advanced Materials Lab.

    1996-06-01

    The retro Diels-Alder reaction was used to modify porosity in hydrocarbon-bridged polysilsesquioxane gels. Microporous polysilsesquioxanes incorporating a thermally labile Diels-Alder adduct as the hydrocarbon bridging group were prepared by sol-gel polymerization of trans-2,3-bis(triethoxysilyl)norbornene. Upon heating the 2,3-norbornenylene-bridges polymers at temperatures above 250 C, the norbornenylene-bridging group underwent a retro Diels-Alder reaction losing cyclopentadiene and leaving behind a ethenylene-bridged polysilsesquioxane. Less than theoretical quantities of cyclopentadiene were volatilized indicating that some of the diene was either reacting with the silanol and olefinic rich material or undergoing oligomerization. Both scanning electron microscopy and nitrogen sorption porosimetry revealed net coarsening of pores (and reduction of surface area) in the materials with thermolysis.

  13. Simulating a Range of Regolith Porosities in the Lab: An Investigation into the Effects of Porosity on Spectral Measurements of Olivine

    Science.gov (United States)

    Evans, R.; Bowles, N. E.; Donaldson Hanna, K. L.

    2016-12-01

    Our current understanding of the composition of planetary bodies primarily comes from remote sensing spectroscopic observations. The interpretation of spectroscopic data requires analogue mineral spectra measured in the lab under appropriate environmental conditions.This is particularly true in the thermal infrared. At these wavelengths porosity, particle size, and near-surface environmental conditions have significant effects on the wavelength position and spectral contrast of diagnostic features. To isolate the effects due to porosity, diffuse reflectance measurements were made from 2.5 to 25 µm of a fine particulate San Carlos olivine sample (University of Oxford's Simulated Lunar Environment Chamber. When measured in diffuse reflectance, we find that as the porosity increases the Christiansen feature (CF, a reflection minimum or emissivity maximum near 8 µm) shifts to longer wavelengths. In the thermal emissivity spectral measurements, we see no discernible shift in the CF position as the porosity changes. In both reflectance and emission the strength and position of the transparency feature (the spectral region from 11 to 13 µm where volume scattering dominates) behaves as expected, as the strength of the feature increases with porosity. In reflectance the relative strength of the reststrahlen bands (RB) were not observed to change systematically with porosity. In this presentation we provide details of our experimental set-up, the range of porosities simulated in the lab, and our spectroscopic results. These new measurements place important constraints for interpreting remote sensing measurements of planetary bodies.

  14. Modeling Flow in Porous Media with Double Porosity/Permeability.

    Science.gov (United States)

    Seyed Joodat, S. H.; Nakshatrala, K. B.; Ballarini, R.

    2016-12-01

    Although several continuum models are available to study the flow of fluids in porous media with two pore-networks [1], they lack a firm theoretical basis. In this poster presentation, we will present a mathematical model with firm thermodynamic basis and a robust computational framework for studying flow in porous media that exhibit double porosity/permeability. The mathematical model will be derived by appealing to the maximization of rate of dissipation hypothesis, which ensures that the model is in accord with the second law of thermodynamics. We will also present important properties that the solutions under the model satisfy, along with an analytical solution procedure based on the Green's function method. On the computational front, a stabilized mixed finite element formulation will be derived based on the variational multi-scale formalism. The equal-order interpolation, which is computationally the most convenient, is stable under this formulation. The performance of this formulation will be demonstrated using patch tests, numerical convergence study, and representative problems. It will be shown that the pressure and velocity profiles under the double porosity/permeability model are qualitatively and quantitatively different from the corresponding ones under the classical Darcy equations. Finally, it will be illustrated that the surface pore-structure is not sufficient in characterizing the flow through a complex porous medium, which pitches a case for using advanced characterization tools like micro-CT. References [1] G. I. Barenblatt, I. P. Zheltov, and I. N. Kochina, "Basic concepts in the theory of seepage of homogeneous liquids in fissured rocks [strata]," Journal of Applied Mathematics and Mechanics, vol. 24, pp. 1286-1303, 1960.

  15. Fabrication of slag-glass composite with controlled porosity

    Directory of Open Access Journals (Sweden)

    Ranko Adziski

    2008-06-01

    Full Text Available The preparation and performance of porous ceramics made from waste materials were investigated. Slag from thermal electrical plant Kakanj (Bosnia and Herzegovina with defined granulations: (0.500÷0.250 mm; (0.250÷0.125 mm; (0.125÷0.063 mm; (0.063÷0.045 mm and 20/10 wt.% of the waste TV screen glass with a granulation <0.063 mm were used for obtaining slag-glass composites with controlled porosity. The one produced from the slag powder fraction (0.125÷0.063 mm and 20 wt.% TV screen glass, sintered at 950°C/2h, was considered as the optimal. This system possesses open porosity of 26.8±1.0%, and interconnected pores with the size of 250–400 μm. The values of E-modulus and bending strength of this composite were 10.6±0.6 GPa and 45.7±0.7 MPa, respectively. The coefficient of thermal expansion was 8.47·10-6/°C. The mass loss in 0.1M HCl solution after 30 days was 1.2 wt.%. The permeability and the form coefficient of the porous composite were K0=0.12 Da and C0=4.53·105 m-1, respectively. The porous composite shows great potential to be used as filters, diffusers for water aeration, dust collectors, acoustic absorbers, etc.

  16. 75 FR 64621 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Furnaces and...

    Science.gov (United States)

    2010-10-20

    ... results which measure energy efficiency, energy use, * * * or estimated annual operating cost of a covered... representative annual operating cost for furnaces and boilers. For fossil-fueled furnaces and boilers, the annual operating cost is the sum of the annual electrical operating cost plus the annual fossil fuel cost. The July...

  17. Space Station Furnace Facility. Experiment/Facility Requirements Document (E/FRD), volume 2, appendix 5

    Science.gov (United States)

    Kephart, Nancy

    1992-01-01

    The function of the Space Station Furnace Facility (SSFF) is to support materials research into the crystal growth and solidification processes of electronic and photonic materials, metals and alloys, and glasses and ceramics. To support this broad base of research requirements, the SSFF will employ a variety of furnace modules operated, regulated, and supported by a core of common subsystems. Furnace modules may be reconfigured or specifically developed to provide unique solidifcation conditions for each set of experiments. The SSFF modular approach permits the addition of new or scaled-up furnace modules to support the evolution of the facility as new science requirements are identified. The SSFF Core is of modular design to permit augmentation for enhanced capabilities. The fully integrated configuration of the SSFF will consist of three racks with the capability of supporting up to two furnace modules per rack. The initial configuration of the SSFF will consist of two of the three racks and one furnace module. This Experiment/Facility Requirements Document (E/FRD) describes the integrated facility requirements for the Space Station Freedom (SSF) Integrated Configuration-1 (IC1) mission. The IC1 SSFF will consist of two racks: the Core Rack, with the centralized subsystem equipment, and the Experiment Rack-1, with Furnace Module-1 and the distributed subsystem equipment to support the furnace.

  18. 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.

  19. Experimental and numerical study of MILD combustion in a lab-scale furnace

    NARCIS (Netherlands)

    Huang, X.; Tummers, M.J.; Roekaerts, D.J.E.M.; Scherer, Viktor; Fricker, Neil; Reis, Albino

    2017-01-01

    Mild combustion in a lab-scale furnace has been experimentally and numerically studied. The furnace was operated with Dutch natural gas (DNG) at 10 kW and at an equivalence ratio of 0.8. OH∗chemiluminescence images were taken to characterize the reaction zone. The chemiluminescence intensity is

  20. 78 FR 41265 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Furnaces and...

    Science.gov (United States)

    2013-07-10

    ... full-fuel cycle as part of the residential furnace and boiler test procedure. (APGA, No. 7 at p. 1... Part 430 RIN 1904-AC96 Energy Conservation Program for Consumer Products: Test Procedures for... notice of proposed rulemaking (NOPR) to amend its test procedure for residential furnaces and boilers...

  1. Calculating analysis of firing different composition artificial coal liquid fuels (ACLF) in the cyclone primary furnace

    Energy Technology Data Exchange (ETDEWEB)

    Tsepenok, A. [Novosibirsk State Technological Univ. (Russian Federation); Joint Stock company ' ' ZiO-COTES' ' , Novosibirsk (Russian Federation); Ovchinnikov, Yu. [Novosibirsk State Technological Univ. (Russian Federation); Serant, F. [Joint Stock company ' ' ZiO-COTES' ' , Novosibirsk (Russian Federation)

    2013-07-01

    This chapter describes the preparation technologies, results of computer simulation of combustion processes in a cyclone primary furnace during firing of artificial coal liquid fuels prepared from different coal grades and results of live testing. As a result the values of unburned carbon, NO{sub x} emissions and other concentrations in the outlet section primary furnace were estimated.

  2. A Furnace for Diffraction Studies using Synchrotron X-Ray Radiation

    DEFF Research Database (Denmark)

    Buras, B.; Lebech, Bente; Kofoed, W.

    1984-01-01

    A furnace for diffraction studies using synchrotron X-ray radiation is described. The furnace can be operated between ambient temperature and 1 800 °C with a temperature stability better than 5 °C for temperatures above 300 °C. Kapton windows allow almost 360° access for the X-ray beam...

  3. 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.

  4. 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.)

  5. 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.

    2017-10-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Yacine DJEGHADER

    2013-06-01

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

  7. 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.

  8. THE WAYS OF IMPROVEMENT OF POWER EFFICIENCY OF INDUSTRIAL FURNACES AT RECUPERATION OF HEAT OF OUTGOING SMOKE

    OpenAIRE

    V. I. Timoshpolskiy; I. A. Trusova; D. V. Mendelev

    2012-01-01

    The main schemes of recovery of waste gases heat, applied in fuel furnaces of metallurgical and machinebuilding production, are analysed, and also criteria of choice of recuperators construction depending on function and constructions of furnaces are considered.

  9. THE WAYS OF IMPROVEMENT OF POWER EFFICIENCY OF INDUSTRIAL FURNACES AT RECUPERATION OF HEAT OF OUTGOING SMOKE

    Directory of Open Access Journals (Sweden)

    V. I. Timoshpolskiy

    2012-01-01

    Full Text Available The main schemes of recovery of waste gases heat, applied in fuel furnaces of metallurgical and machinebuilding production, are analysed, and also criteria of choice of recuperators construction depending on function and constructions of furnaces are considered.

  10. Porosity characterization of fresh and altered stones by ultrasound velocity and mercury intrusion porosimetry

    Science.gov (United States)

    Scrivano, Simona; Gaggero, Laura; Gisbert Aguilar, Josep

    2016-04-01

    Porosity is the main physical feature dealing with rocks durability and storage capacity. The analysis of this parameter is key factor in predicting rock performances (Molina et al., 2011). There are several techniques that can be applied to acquire the widest information range possible about pores (e.g. size, shape, distribution), leading to a better understanding of decay processes and trapping capacity. The coupling of a detailed minero-petrographic analysis with physical measures such as ultrasounds and mercury intrusion porosimetry (MIP) proved to be a valid tool for understanding the porous network and its evolution during weathering processes. Both fresh and salt-weathered samples were analysed to investigate the modification triggered in the porous network by crystallization. The ageing process was induced using a Na2SO4 saturated saline solution with the partial continuous immersion method (Benavente et al., 2001). The study was addressed to four sedimentary lithotypes: 1) Arenaria Macigno, a greywacke made up of thickened clasts of quartz, plagioclase and K-feldspar cemented by micritic calcite and phyllosilicates; 2) Breccia Aurora, a calcareous breccia with nodules of compact limestone and micritic cement joints; 3) Rosso Verona, a biomicrite where the compact bio-micrite matrix is cut by clay minerals veins; and 4) Vicenza Stone, an organogenic limestone rich in micro- and macro foraminifera, algae, bryozoans and remains of echinoderms, with iron oxides. An appropriate description of the porous network variation and recognition of the origin of secondary porosity was attained. The study defined that the pore shape and distribution (anisotropy coefficient K) has a fluctuation up to the 50% after weathering treatments and pore-size distribution (defined in a range between 0,0025 - 75 μm), allowing modelling the mechanisms of water transport and evaluating decay susceptibility of these lithotypes. Molina E, Cultrone G, Sebastián E, Alonso FJ, Carrizo L

  11. Investigation on the Effect of Cooling Rate on Hot Tearing Susceptibility of Al2024 Alloy Using Thermal Analysis

    Science.gov (United States)

    Shabestari, S. G.; Ghoncheh, M. H.

    2015-12-01

    Effect of different cooling rates and Al-5Ti-1B grain refiner on hot tearing susceptibility of Al2024 alloy were studied using thermal analysis. Influence of cooling rates on microsegregation, and the amount of gas and shrinkage porosities was investigated. The cooling rates used in the present study range from 0.4 to 17.5 K s-1. To evaluate the hot tearing susceptibility, Clyne and Davies' criterion is used. To calculate solid fraction during solidification, solid fraction vs time is plotted based on Newtonian technique via thermal analysis. The results show that the hot tearing susceptibility reduces initially by increasing the cooling rate and then increases at higher cooling rates. Hot tearing susceptibility is decreased by grain refinement. Solidification characteristics of Al2024 e.g., microsegregation, gas, and shrinkage porosities are decreased by increasing cooling rate.

  12. 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)

  13. Coke properties in simulated blast furnace conditions:investigation on hot strength, chemical reactivity and reaction mechanism

    OpenAIRE

    Haapakangas, J. (Juho)

    2016-01-01

    Abstract The blast furnace – basic oxygen furnace route remains the most utilised process route in the production of steel worldwide. Coke is the main fuel of the blast furnace process, however, coke producers and blast furnace operators are facing significant challenges due to increased demands on coke quality and decrease of prime coking coals. The estimation of coke performance in the industrial process through accurate laboratory analyses is of increasing importance. In this doctor...

  14. Double porosity models for the description of water infiltration in wood

    DEFF Research Database (Denmark)

    Krabbenhøft, Kristian; Damkilde, Lars

    2004-01-01

    In this paper some of the possibilities of applying double porosity and permeability models to the problem of water infiltration in wood are explored. It is shown that the double porosity model can capture a number of commonly reported anomalies including two-stage infiltration/sorption and appar......In this paper some of the possibilities of applying double porosity and permeability models to the problem of water infiltration in wood are explored. It is shown that the double porosity model can capture a number of commonly reported anomalies including two-stage infiltration...

  15. Prediction of soil water retention properties using pore-size distribution and porosity

    National Research Council Canada - National Science Library

    Beckett, Christopher T.S; Augarde, Charles E

    2013-01-01

    .... This paper presents a method that builds on previous techniques by incorporating porosity and particles of different sizes, shapes, and separation distances to predict soil water retention properties...

  16. Effect of shrinkage porosity on mechanical properties of ferritic ductile iron

    Directory of Open Access Journals (Sweden)

    Wang Zehua

    2013-05-01

    Full Text Available Casting defects could largely affect the mechanical properties of casting products. A number of test pieces made of ductile iron (EN-GJS-400-18-LT with different levels of shrinkage porosity were prepared and then tensile and fatigue tests were performed to investigate the impact of shrinkage porosity on their mechanical properties. The results showed that the tensile strength decreases linearly with increasing of the shrinkage porosity. The tensile elongation decreases sharply with the increase of the shrinkage porosity mainly due to the non-uniform plastic deformation. The fatigue life also dramatically declines with increasing of the porosity and follows a power law relationship with the area percentage of porosity. The existence of the shrinkage porosity made the fatigue fracture complex. The shrinkage pores, especially those close to the surface usually became the crack initiation sites. For test pieces with less porosity, the fatigue fracture was clearly composed of crack initiation, propagation, and overloading. While for samples with high level of porosity, multiple crack initiation sites were observed.

  17. Double Porosity Models For the Description of Water Infiltration In Wood

    DEFF Research Database (Denmark)

    Kristian, Krabbenhøft; Damkilde, Lars

    2004-01-01

    In this paper some of the possibilities of applying double porosity and permeability models to the problem of water infiltration in wood are explored. It is shown that the double porosity model can capture a number of commonly reported anomalies including two-stage infiltration/sorption and appar......In this paper some of the possibilities of applying double porosity and permeability models to the problem of water infiltration in wood are explored. It is shown that the double porosity model can capture a number of commonly reported anomalies including two-stage infiltration...

  18. [Multi-spectral measurement of Basic oxygen furnace flame temperature].

    Science.gov (United States)

    Wang, Yong-Qing; Chen, Yan-Ru; Zhao, Qi; Chen, Fei-Nan; Chen, Jing-Jing

    2012-11-01

    A multi-wavelength analysis method is introduced to measure the temperature of basic oxygen furnace flame. In this study, USB4000 spectrometer was applied to obtain radiation spectrum of flame within wavelength range 200-1 100 nm, from which the flame temperature and monochromatic emissivity was derived by Levenberg-Marquart modeling method. Wavelet neural network was applied to process the spectral measurement data, which could cancel the assumption model of emissivity and wavelengths. It is a kind of valid method to acquire the true temperature and spectral emissivity. Each neuron in the hidden layer of a feed-forward network is a combination of the sigmoidal activation function (SAF) and morlet wavelet activation function (WAF). The output of the hidden neuron is the product of the output from these two activation functions.

  19. Oxidation Character of Carbon Composite Bricks Used in Blast Furnace

    Science.gov (United States)

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

    The carbon composite brick is a new refractory used in blast furnace hearth and bottom. It caused wide attention due to its high thermal conductivity and low erosion by molten iron. In this paper, chemical constituents, SEM-EDS and X-ray diffraction were carried out in order to understand reaction mechanisms. A series of experiments of oxidation resistance characteristics were made. The oxidation mechanisms of carbon composite bricks in the presence of air were analyzed. According to the analysis on many experimental results, the oxidation process of carbon composite bricks under different temperatures were controlled by different mechanisms. In the condition of high temperature, SiO2 as oxidation product hindered the diffusion of O2, and reduced the oxidation loss of graphite in the internal.

  20. Modeling of Radiative Heat Transfer in an Electric Arc Furnace

    Science.gov (United States)

    Opitz, Florian; Treffinger, Peter; Wöllenstein, Jürgen

    2017-12-01

    Radiation is an important means of heat transfer inside an electric arc furnace (EAF). To gain insight into the complex processes of heat transfer inside the EAF vessel, not only radiation from the surfaces but also emission and absorption of the gas phase and the dust cloud need to be considered. Furthermore, the radiative heat exchange depends on the geometrical configuration which is continuously changing throughout the process. The present paper introduces a system model of the EAF which takes into account the radiative heat transfer between the surfaces and the participating medium. This is attained by the development of a simplified geometrical model, the use of a weighted-sum-of-gray-gases model, and a simplified consideration of dust radiation. The simulation results were compared with the data of real EAF plants available in literature.

  1. Pragmatic analysis of the electric submerged arc furnace continuum

    Science.gov (United States)

    Karalis, K.; Karkalos, N.; Antipas, G. S. E.; Xenidis, A.

    2017-09-01

    A transient mathematical model was developed for the description of fluid flow, heat transfer and electromagnetic phenomena involved in the production of ferronickel in electric arc furnaces. The key operating variables considered were the thermal and electrical conductivity of the slag and the shape, immersion depth and applied electric potential of the electrodes. It was established that the principal stimuli of the velocities in the slag bath were the electric potential and immersion depth of the electrodes and the thermal and electrical conductivities of the slag. Additionally, it was determined that, under the set of operating conditions examined, the maximum slag temperature ranged between 1756 and 1825 K, which is in accordance with industrial measurements. Moreover, it was affirmed that contributions to slag stirring due to Lorentz forces and momentum forces due to the release of carbon monoxide bubbles from the electrode surface were negligible.

  2. Optimisation of metal charge material for electric arc furnace

    Directory of Open Access Journals (Sweden)

    T. Lis

    2011-10-01

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

  3. Practical Active Disturbance Rejection Solution for Furnace Temperature Control System

    Directory of Open Access Journals (Sweden)

    Jian Huan Su

    2014-08-01

    Full Text Available A practical active disturbance rejection control (ADRC solution is proposed for the furnace temperature system. Employing a linear reduced-order model with optimized parameters, the practical ADRC is simple to use, easy to tune and energy-efficient in dealing with the uncertainties and disturbances in plant dynamics. Through the order reduction in both the plant model and the state observer, we develop a first order extended state observer for estimating in real-time the total value of the external and internal disturbances. The practical and standard ADRCs outperform the Smith Predictor and the PID controller in disturbance-rejection and robustness; however, the practical ADRC has fewer adjustable parameters and significantly smaller energy consumption than the standard ADRC, making it a viable candidate for industrial applications.

  4. Characterization of a Mono-Ellipsoidal Imaging Furnace

    Energy Technology Data Exchange (ETDEWEB)

    Guesdon, C.; Alxneit, I.; Tschudi, H.R.; Wuillemin, D.; Brunner, Y.; Winkel, L.; Sturzenegger, M.

    2004-03-01

    An imaging furnace was built and tested for investigating chemical reactions that involve melts and the release of condensable gases. A key feature is the sample stage with a water-cooled sample support to avoid reaction of the sample with crucible material. A built-in hammer allows for freezing the high-temperature composition of the sample and a glass dome above the sample allows for experiments under defined atmospheres. Measured peak flux densities on samples with a diameter of 5 mm clearly exceed 500 Wcm{sub -2} producing sample temperatures of at least 2500 K. Cold experiments with a smoke source at the place of the sample as well as decomposition experiments with chalcocite (Cu{sub 2}S) proved that an appropriate gas flow through the dome keeps the dome free of condensates. (author)

  5. A Review of Granulation Process for Blast Furnace Slag

    Directory of Open Access Journals (Sweden)

    Yu Pengfei

    2016-01-01

    Full Text Available Molten slags of blast furnace is a second resources with great value of 1600~1 800 MJ sensible heat per ton. At present, water-quenching process plays a leading role in recovering waste heat of the molten slags. However, this method not only cost lots of water, but also recover little sensible heat and can pollute the surrounding environment. Dry granulation process, as an environmentally friendly method with high-efficiency heat recovery, have attracted widespread attentions. In this paper, the water quenching and dry granulation processes were discussed in detail. After a thorough comparative analysis of various treatment technologies, it can be concluded that centrifugal granulation affiliated with dry granulation is the optimum process, with smaller slag particle size (about 2mm, more glassy phase and higher recovery rate.

  6. Iron loss in high-power arc steelmaking furnaces

    Directory of Open Access Journals (Sweden)

    V. P. Karasyov

    2016-07-01

    Full Text Available There is considered the power operating mode of a high-power arc steelmaking furnaces (ASMF in the period of the flat bath. It is revealed that electric energy is mainly spent for heating and overheating the foamed slag. Heat transferring from slag to metal is carried out by the convective agitation of the bath. For agitation there is used intensive purging of the bath with oxygen that causes increased iron losses with the running foamed slag. There are noted the negative points of working with the foamed slag. It is recommended to expand R&D in the field of optimizing the power operating mode of high-power ASMF.

  7. 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.

  8. Challenges in simulation of chemical processes in combustion furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M.; Kilpinen, P. [Aabo Akademi, Turku (Finland)

    1996-12-31

    The presentation gives an introduction to some of the present issues and problems in treating the complex chemical processes in combustion. The focus is in the coupling of the hydrocarbon combustion process with nitrogen oxide formation and destruction chemistry in practical furnaces or flames. Detailed kinetic modelling based on schemes of elementary reactions are shown to be a useful novel tool for identifying and studying the key reaction paths for nitrogen oxide formation and destruction in various systems. The great importance of the interaction between turbulent mixing and combustion chemistry is demonstrated by the sensitivity of both methane oxidation chemistry and fuel nitrogen conversion chemistry to the reactor and mixing pattern chosen for the kinetic calculations. The fluidized bed combustion (FBC) nitrogen chemistry involves several important heterogeneous reactions. Particularly the char in the bed plays an essential role. Recent research has advanced rapidly and the presentation proposes an overall picture of the fuel nitrogen reaction routes in circulating FBC conditions. (author)

  9. 40 CFR 424.10 - Applicability; description of the open electric furnaces with wet air pollution control devices...

    Science.gov (United States)

    2010-07-01

    ... electric furnaces with wet air pollution control devices subcategory. 424.10 Section 424.10 Protection of... MANUFACTURING POINT SOURCE CATEGORY Open Electric Furnaces With Wet Air Pollution Control Devices Subcategory § 424.10 Applicability; description of the open electric furnaces with wet air pollution control devices...

  10. Nodal wear model: corrosion in carbon blast furnace hearths

    Directory of Open Access Journals (Sweden)

    Verdeja, L. F.

    2003-06-01

    Full Text Available Criterions developed for the Nodal Wear Model (NWM were applied to estimate the shape of the corrosion profiles that a blast furnace hearth may acquire during its campaign. Taking into account design of the hearth, the boundary conditions, the characteristics of the refractory materials used and the operation conditions of the blast furnace, simulation of wear profiles with central well, mushroom and elephant foot shape were accomplished. The foundations of the NWM are constructed considering that the corrosion of the refractory is a function of the temperature present at each point (node of the liquid metal-refractory interface and the corresponding physical and chemical characteristics of the corrosive fluid.

    Se aplican los criterios del Modelo de Desgaste Nodal (MDN para la estimación de los perfiles de corrosión que podría ir adquiriendo el crisol de un homo alto durante su campaña. Atendiendo al propio diseño del crisol, a las condiciones límites de contorno, a las características del material refractario utilizado y a las condiciones de operación del horno, se consiguen simular perfiles de desgaste con "pozo central", con "forma de seta" ó de "pie de elefante". Los fundamentos del MDN se apoyan en la idea de considerar que la corrosión del refractario es función de la temperatura que el sistema pueda presentar en cada punto (nodo de la intercara refractario-fundido y de las correspondientes características físico-químicas del fluido corrosivo.

  11. MODELING PARAMETERS OF ARC OF ELECTRIC ARC FURNACE

    Directory of Open Access Journals (Sweden)

    R.N. Khrestin

    2015-08-01

    Full Text Available Purpose. The aim is to build a mathematical model of the electric arc of arc furnace (EAF. The model should clearly show the relationship between the main parameters of the arc. These parameters determine the properties of the arc and the possibility of optimization of melting mode. Methodology. We have built a fairly simple model of the arc, which satisfies the above requirements. The model is designed for the analysis of electromagnetic processes arc of varying length. We have compared the results obtained when testing the model with the results obtained on actual furnaces. Results. During melting in real chipboard under the influence of changes in temperature changes its properties arc plasma. The proposed model takes into account these changes. Adjusting the length of the arc is the main way to regulate the mode of smelting chipboard. The arc length is controlled by the movement of the drive electrode. The model reflects the dynamic changes in the parameters of the arc when changing her length. We got the dynamic current-voltage characteristics (CVC of the arc for the different stages of melting. We got the arc voltage waveform and identified criteria by which possible identified stage of smelting. Originality. In contrast to the previously known models, this model clearly shows the relationship between the main parameters of the arc EAF: arc voltage Ud, amperage arc id and length arc d. Comparison of the simulation results and experimental data obtained from real particleboard showed the adequacy of the constructed model. It was found that character of change of magnitude Md, helps determine the stage of melting. Practical value. It turned out that the model can be used to simulate smelting in EAF any capacity. Thus, when designing the system of control mechanism for moving the electrode, the model takes into account changes in the parameters of the arc and it can significantly reduce electrode material consumption and energy consumption

  12. Slagging and Fouling Characteristics of HRSG for Ferrosilicon Electric Furnaces

    Directory of Open Access Journals (Sweden)

    Yungang Wang

    2015-02-01

    Full Text Available The slagging and fouling characteristics of the heat recovery steam generator (HRSG for ferrosilicon electric furnaces are discussed in this paper. Three ash samples were taken from the HRSG of a ferrosilicon furnace in Ningxia Province, China, which suffered from serious slagging and fouling. X-ray fluorescence (XRF, X-ray powder diffraction (XRD and scanning electron microscope (SEM were used to analyze the ash samples. The results show that low melting point salt Na2SO4 and composite salts Na (AlSi3O8 and 3K2SO4·CaSO4 deposit on the superheater tube walls in aerosol form and solidify to form the initial slag layer. With the continuous deposition of the low melting point compounds, more and more ash particles in the flue gas adhere to the slag surface to form a thicker slag. Low melting point composite salt NaO·Al2O3·SiO2 is absorbed on the evaporator tube walls in aerosol form. With the deposition of NaO·Al2O3·SiO2, more and more ash particles are absorbed to form the fouling. Since there is less space between pin-finned tubes, the large iron-rich slag particles are easily deposited on tube walls and fin surfaces, which is advantageous to the fouling process. There are large quantities of superfine ash particles in the flue gas that easily adhere to other particles or tube walls, which facilitates the slagging and fouling process.

  13. Contributions to the study of porosity in fly ash-based geopolymers. Relationship between degree of reaction, porosity and compressive strength

    Directory of Open Access Journals (Sweden)

    Y. Luna-Galiano

    2016-09-01

    Full Text Available The main contribution of this paper relates to the development of a systematic study involving a set of parameters which could potentially have an impact on geopolymer properties: curing temperature, type of activating solution, alkali metal in solution, incorporation of slag (Ca source and type of slag used. The microstructures, degrees of reaction, porosities and compressive strengths of geopolymers have been evaluated. Geopolymers prepared with soluble silicate presented a more compacted and closed structure, a larger amount of gel, lower porosity and greater compressive strength than those prepared with hydroxides. On the other hand, Na-geopolymers were more porous but more resistant than K-geopolymers. Although there is an inverse relation between degree of reaction and porosity, between compressive strength and porosity it is not always inversely proportional and could, in some cases, be masked by changes produced in other influencing parameters.

  14. Cracking susceptibility of aluminum alloys during laser welding

    Directory of Open Access Journals (Sweden)

    Lara Abbaschian

    2003-06-01

    Full Text Available The influence of laser parameters in welding aluminum alloys was studied in order to reduce hot cracking. The extension of cracks at the welding surface was used as a cracking susceptibility (CS index. It has been shown that the CS changes with changing welding velocity for binary Al-Cu alloys. In general, the CS index increased until a maximum velocity and then dropped to zero, generating a typical lambda-curve. This curve is due to two different mechanisms: 1 the refinement of porosities with increasing velocity and 2 the changes in the liquid fraction due to decreasing microsegregation with increasing velocities.

  15. The development of two new KC-135 furnaces for studies on microgravity materials processing

    Science.gov (United States)

    Fiske, Michael; Cockburn, James; Poorman, Richard

    1988-01-01

    Wyle Laboratories is currently designing and fabricating two KC-135 materials processing furnaces for Marshall Space Flight Center. The first of these, called the Rapid Melt/Rapid Quench (RM/RQ) Furnace, will be used to melt and resolidify Cu-, Al-, and Ni-based alloys and composites, all during the 20 to 30 seconds of low gravity (0.1 to 0.001 g) available in a single parabola of the KC-135. In addition, it will be capable of directional solidification of these alloys. The furnace can be configured for either liquid or gas quenching of the samples. The second furnace, called the Polymer Solidification Transparent (PST) Furnace, will use a wide range of sample translation rates to directionally solidify polymers and low-melting-point metals as the KC-135 flies a series of parabolic maneuvers. The use of transparent crucibles and an optics system between the hot and cold zones of the furnace will allow for high-resolution video monitoring of the solid-liquid interface during processing. It is hoped that the development of these two furnaces will lead to significant increases in understanding of interface kinetics, fluid flow, and heat transfer in materials during solidification in a low-gravity environment.

  16. 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)

  17. Influence of furnace tube shapeon thermal strain of fire-tube boilers

    Directory of Open Access Journals (Sweden)

    Gaćeša Branka

    2014-01-01

    Full Text Available The aim of this paper is to use numerical analysis and fine element method-FEM to investigate the influence of furnace tube shape on the thermal strain of fire-tube boilers. Thermal stresses in corrugated furnace tubes of different shape, i.e. with different corrugation pitch and depth, were analysed first. It was demonstrated that the thermal stresses in corrugated furnace tube are significantly reduced with the increase of corrugation depth. Than deformations and stresses in the structure of a fire-tube boiler were analysed in a real operating condition, for the cases of installed plain furnace tube and corrugated furnace tubes with different shapes. It was concluded that in this fire-tube boiler, which is of larger steam capacity, the corrugated furnace tube must be installed, as well as that the maximal stress in the construction is reduced by the installation of the furnace tube with greater corrugation depth. The analysis of stresses due to pressure and thermal loads pointed out that thermal stresses are not lower-order stresses in comparison to stresses due to pressure loads, so they must be taken into consideration for boiler strength analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR 35040 i br. TR 35011

  18. Characterising the blast furnace cohesive zone as high PCI: final report

    Energy Technology Data Exchange (ETDEWEB)

    Danloy, G.; Mignon, J.; Oury, L.; Bolignano, G.; Pisteeli, M.I.; Gelli, I.; Hahlin, P. [CRM, Leige (Belgium)

    2002-07-01

    The research aimed to characterise the permeability to gas of the blast furnace burden during softening and melting, to develop an improved model of the blast furnace cohesive zone, and to introduce this model into a general model of the blast furnace in order to assess ways to increase PCI rates. Softening and melting experimental tests were carried out on five types of materials: olivine pellets, acid pellets, and sinters of three different basicities. The conclusion of the test is that the two main factors controlling the reduction of the burden material, and with that the meltdown properties, are the hydrogen content, resulting from the PCI rate, and the temperature increase rate, resulting from the rate of descent in the blast furnace. Based on these experimental results, a model of the cohesive zone was developed, which compares very well with the observations made on dissected blast furnaces. Finally, the blast furnace model has been used to study the influence on the cohesive zone and on some blast furnace performances of the variables affecting the cohesive zone permeability, essentially burned composition and chemistry. The influence of the layers thickness has also been assessed.

  19. Fluid dynamics simulation of the reheating furnace of the continuous mill line of VBM

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Lis Nunes; Silva, Ricardo Junqueira [V e M do Brasil S.A., Belo Horizonte. MG (Brazil)

    2009-11-01

    V and M do Brazil is an integrated steel mill with the production of seamless steel pipe. The manufacture process comprises heating and reheating fuel fired furnaces within two rolling mills lines. The Continuous Mill line reheating furnace has no baffle between heating and soaking zone that might cause a thermofluidodynamics influence between control zones and consequently an overall unbalance within the furnace. The combustion control mesh is based at the real measured temperature per zone. If the thermocouples of the heating zone are influenced by the heat flux coming from the soaking zone, the mesh might receive a wrong temperature signal and send to the heating zone burners a lower thermal demand than the real needed one. The flux unbalance may cause homogeneity problems and/or early equipment worn out. Using the software FLUENT, it was made a 2D fluid dynamic simulation of the reheating furnace with and without a baffle in order to have a qualitative view of its influence in the hot gas flux inside the furnace. Through the simulation it was possible to check the furnace homogeneity gain potential with the installation of the baffle and its better position. The results of this study supported the company decision to actually invest in a baffle installation in this furnace. Further studies will be done to quantify the results of the process. (author)

  20. Simulation for the powder movement and accumulation in the lower part of blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Sugiyama, Takashi [Mineral Resources Research Center, Nippon Steel Technoresearch, Futtsu-shi Chiba (Japan)

    1997-12-31

    The behavior of unburnt char and coke powder in the blast furnace becomes material for discussion with the increase in injection rate of pulverized coal into the blast furnace. An analysis was made as to the simulation of powder accumulation at the deadman and dripping zone of blast furnace by using a powder/gas two-phases flow experimental data. When an excessive powder has penetrated at a low gas velocity, it brings an increment in holdup and the controlling factors are powder/gas ratio and gas velocity. An empirical formula used for estimating the powder hold-up in the blast furnace internal conditions has proposed based on similarity. The controlling {pi} numbers are Floude number, powder/gas ratio and particle diameter ratio of powder/lump. This empirical formular was connected with Blast Furnace Total Model `BRIGHT` for the simulation of powder amount distribution in the lower part of blast furnace. When Powder diameter Dk exceeds 100 {mu} and gas velocity becomes lower than 0.7m/s at PC1OOkg/T, the powder tends to accumulate in the deadman. These results was available for the decision of optimum blast conditions and optimum powder diameter in the high amount of pulverized coal injection to the blast furnace. (author) 10 refs.

  1. Plasma sintering of unalloyed iron: a study of surface porosity

    Directory of Open Access Journals (Sweden)

    Lourenço Jorge Magner

    2004-01-01

    Full Text Available Samples of unalloyed iron powder were compacted and sintered in an abnormal glow discharge, generated in a gas mixture of 80% Ar + 20% H2 by using a pulsed power source. The samples were placed on a holder, acting as the discharge cathode, and were heated by the bombardment of ions, strongly accelerated in the cathode sheath. Sintering was performed at temperatures of 1173, 1273 and 1373 K for 30 min, varying the voltage applied to the cathode from 400 to 700 V and pressure ranging from 470 to 2650 Pa. It is shown that the kinetic energy of ions striking the sample surface increased approximately three times, when the voltage changed from 400 to 700 V, with a corresponding reduction of surface porosity. The surface sealing is related to the ion bombardment, which produced a high mobility of surface atoms and consequent enhanced diffusion as well as sputtering and condensation on the concave surface, resulting in an activation of surface sintering.

  2. The Porosity of the neutral ISM in 20 THINGS Galaxies

    Science.gov (United States)

    Bagetakos, I.; Brinks, E.; Walter, F.; de Blok, W. J. G.; Usero, A.; Leroy, A. K.; Rich, J. W.; Kennicutt, R. C.

    2011-11-01

    We present an analysis of the properties of H i holes detected in 20 galaxies that are part of "The H i Nearby Galaxy Survey". We detected more than 1000 holes in total in the sampled galaxies. The holes are found throughout the disks of the galaxies, out to the edge of the H i disk. We find that shear limits the age of holes in spirals. Shear is less important in dwarf galaxies which explains why H i holes in dwarfs are rounder, on average than in spirals. Shear is particularly strong in the inner part of spiral galaxies, limiting the lifespan of holes there and explaining why we find that holes outside R25 are larger and older. We proceed to derive the surface and volume porosity and find that this correlates with the type of the host galaxy: later Hubble types tend to be more porous. The size distribution of the holes in our sample follows a power law with a slope of aν ~ -2.9. Assuming that the holes are the result of massive star formation, we derive values for the supernova rate (SNR) and star formation rate (SFR) which scales with the SFR derived based on other tracers. If we extrapolate the observed number of holes to include those that fall below our resolution limit, down to holes created by a single supernova, we find that our results are compatible with the hypothesis that H i holes result from star formation.

  3. Boiling radial flow in fractures of varying wall porosity

    Energy Technology Data Exchange (ETDEWEB)

    Barnitt, Robb Allan

    2000-06-01

    The focus of this report is the coupling of conductive heat transfer and boiling convective heat transfer, with boiling flow in a rock fracture. A series of experiments observed differences in boiling regimes and behavior, and attempted to quantify a boiling convection coefficient. The experimental study involved boiling radial flow in a simulated fracture, bounded by a variety of materials. Nonporous and impermeable aluminum, highly porous and permeable Berea sandstone, and minimally porous and permeable graywacke from The Geysers geothermal field. On nonporous surfaces, the heat flux was not strongly coupled to injection rate into the fracture. However, for porous surfaces, heat flux, and associated values of excess temperature and a boiling convection coefficient exhibited variation with injection rate. Nucleation was shown to occur not upon the visible surface of porous materials, but a distance below the surface, within the matrix. The depth of boiling was a function of injection rate, thermal power supplied to the fracture, and the porosity and permeability of the rock. Although matrix boiling beyond fracture wall may apply only to a finite radius around the point of injection, higher values of heat flux and a boiling convection coefficient may be realized with boiling in a porous, rather than nonporous surface bounded fracture.

  4. Thermochemistry of zeolitic imidazolate frameworks of varying porosity.

    Science.gov (United States)

    Hughes, James T; Bennett, Thomas D; Cheetham, Anthony K; Navrotsky, Alexandra

    2013-01-16

    The first thermochemical analysis by room-temperature aqueous solution calorimetry of a series of zeolite imidazolate frameworks (ZIFs) has been completed. The enthalpies of formation of the evacuated ZIFs-ZIF-zni, ZIF-1, ZIF-4, CoZIF-4, ZIF-7, and ZIF-8-along with as-synthesized ZIF-4 (ZIF-4·DMF) and ball-milling amorphized ZIF-4 (a(m)ZIF-4) were measured with respect to dense components: metal oxide (ZnO or CoO), the corresponding imidazole linker, and N,N dimethylformamide (DMF) in the case of ZIF-4·DMF. Enthalpies of formation of ZIFs from these components at 298 K are exothermic, but the ZIFs are metastable energetically with respect to hypothetical dense components in which zinc is bonded to nitrogen rather than oxygen. These enthalpic destabilizations increase with increasing porosity and span a narrow range from 13.0 to 27.1 kJ/mol, while the molar volumes extend from 135.9 to 248.8 cm(3)/mol; thus, almost doubling the molar volume results in only a modest energetic destabilization. The experimental results are supported by DFT calculations. The series of ZIFs studied tie in with previously studied MOF-5, creating a broader trend that mirrors a similar pattern by porous inorganic oxides, zeolites, zeotypes, and mesoporous silicas. These findings suggest that no immediate thermodynamic barrier precludes the further development of highly porous materials.

  5. Patterning of dispenser cathode surfaces to a controlled porosity

    Science.gov (United States)

    Garner, Charles E.; Deininger, William D.; Gibson, John; Thomas, Richard

    1989-01-01

    A process to pattern slots approximately 1.25 microns in width into 25-micron-thick W films that have been deposited onto flat or concave surfaces is discussed. A 25-micron-thick W film with a high degree of (100) orientation is chemically vapor deposited (CVD) onto a flat or concave Mo mandrel. A 5-micron-thick Al film is deposited onto the CVD W, followed by 2 microns of photoresist. On concave cathodes, XeCl2 laser ablation or X-ray lithography is used to pattern the photoresist, whereas on flat cathodes deep UV lithography can be used. The patterned photoresist serves as the mask in a Cl ion-beam-assisted etching (IBAE) process to pattern the Al. An alternative process is to deposit Al2O3 films onto the W and pattern the Al2O3 using laser ablation. The W film is then patterned to 3-6-micron slot widths using IBAE + ClF3 with the patterned Al or Al2O3 as the mask. Finally, a sputter deposition step is required to close up the slots to approximately 1 micron. The process described is capable of patterning concave dispenser cathodes to a controlled and precise porosity.

  6. Environmental stresses and strains in an extreme situation: the repair of electrometallurgy furnaces.

    Science.gov (United States)

    Chaurel, C; Mercier-Gallay, M; Stoklov, M; Romazini, S; Perdrix, A

    1993-01-01

    Whenever continuous casting furnace breaks down, the emergency intervention necessary to repair it has to be carried out under exceptional environmental conditions caused mainly by heat, as the furnace must be stopped for the shortest possible time. In this study, we aimed to evaluate the stresses and strains to which boilermakers are subjected during the replacement of an electrode element of a 20 MW furnace. The thermal stress was evaluated by the wet bulb globe temperature (WBGT) index. CO2 was measured continuously at the furnace periphery and sporadically in the center of the furnace using an electrochemical method, while CO was also measured in both areas, using Dräger tubes. Dusts were sampled by a CPM3 (Andersen particle fractionating sampler) and a CIP10 (personal sampler). The strain was evaluated by continuous ECG recording with an Aclan IFC 85, breathing performance was assessed with an HI 298 microspirometer, and blood oxygen saturation was evaluated using a Biox oximeter. Thermal stresses are extreme: WBGT was 55 degrees C in the furnace center and 34 degrees C in the furnace periphery. In spite of the ventilation, the reduction in heat during the 6 h of the intervention was negligible and did not provide sufficient cooling. The analysis of gases and dusts were of minor interest, although the mean CO level at the furnace periphery was 40 ppm, with a peak level of 140 ppm in furnace center. CO2 and SO2 levels did not exceed TLV-TWA and TLV-Stel values.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Influence of blast furnace gas flow speed on dust deposition characteristics in butterfly valve region

    Directory of Open Access Journals (Sweden)

    Lixin WANG

    2016-02-01

    Full Text Available The blast furnace gas contains plenty of dust, which deposits easily on the bottom of seat sealing surface of the tri-eccentric butterfly valve in the pipeline, causing stuck and damage to the valve plate, thereby affects the production of the blast furnace and brings great economic loss. To derive the influence mechanism of effects of the blast furnace gas flow speed within the pipeline on the dust deposition laws in the butterfly valve region, a 3D model of the butterfly valve and its regional flow field is built with Pro/E software. Based on FLUENT module of ANSYS Workbench, along with standard k-ε turbulence model and DPM model, simulation analysis of moving trajectories of dust particles in butterfly valve region under 3 blast furnace gas flow speeds is conducted. Results show that the deposition mass of dust particles decreases firstly, then increases with the enlargement of valve plate opening angle under the blast furnace gas flow speed of 8 m/s, while decreases with the enlargement of valve plate opening under the blast furnace gas flow speeds of 12 m/s and 16 m/s. In the case of the valve plate opening angle of 15°, the deposition rate of dust particles increases with the growing of blast furnace gas flow speed, while decreases with the growing of blast furnace gas flow speed under the cases of valve plate opening angle of 45° and 75°. The research results provide a theoretical reference for the development of automatic dust removal system in the butterfly valve region of the blast furnace gas pipeline.

  8. Olive Crown Porosity Measurement Based on Radiation Transmittance: An Assessment of Pruning Effect

    Directory of Open Access Journals (Sweden)

    Francisco J. Castillo-Ruiz

    2016-05-01

    Full Text Available Crown porosity influences radiation interception, air movement through the fruit orchard, spray penetration, and harvesting operation in fruit crops. The aim of the present study was to develop an accurate and reliable methodology based on transmitted radiation measurements to assess the porosity of traditional olive trees under different pruning treatments. Transmitted radiation was employed as an indirect method to measure crown porosity in two olive orchards of the Picual and Hojiblanca cultivars. Additionally, three different pruning treatments were considered to determine if the pruning system influences crown porosity. This study evaluated the accuracy and repeatability of four algorithms in measuring crown porosity under different solar zenith angles. From a 14° to 30° solar zenith angle, the selected algorithm produced an absolute error of less than 5% and a repeatability higher than 0.9. The described method and selected algorithm proved satisfactory in field results, making it possible to measure crown porosity at different solar zenith angles. However, pruning fresh weight did not show any relationship with crown porosity due to the great differences between removed branches. A robust and accurate algorithm was selected for crown porosity measurements in traditional olive trees, making it possible to discern between different pruning treatments.

  9. Effect of porosity and pore morphology on the low-frequency ...

    Indian Academy of Sciences (India)

    the imperfections, e.g. porosity, impurities, grain boundaries, micro-cracks, ran- dom crystal orientations etc. It is evident from the earlier studies [1–3] that the losses in sintered polycrystalline ceramics are strongly affected by these extrinsic factors. Few of the earlier work deals with the effect of only total porosity on the. 309 ...

  10. Investigation of surface porosity measurements and compaction pressure as means to ensure consistent contact angle determinations

    DEFF Research Database (Denmark)

    Holm, René; Borkenfelt, Simon; Allesø, Morten

    2016-01-01

    .g. increase the wetting from a solid dosage form. Since surface roughness of the compact has been suggested to influence the measurement this study investigated if the surface quality, in terms of surface porosity, had an influence on the measured contact angle. A correlation to surface porosity was observed...

  11. Porosity testing methods for the quality assessment of selective laser melted parts

    NARCIS (Netherlands)

    Wits, Wessel W.; Carmignato, Simone; Zanini, Filippo; Vaneker, Thomas H.J.

    2016-01-01

    This study focuses on the comparison of porosity testing methods for the quality assessment of selective laser melted parts. Porosity is regarded as important quality indicator in metal additive manufacturing. Various destructive and non-destructive testing methods are compared, ranging from global

  12. Geometry Properties of Porosity Waves during Magma Migration: The Influence of Viscosities and Damage

    Science.gov (United States)

    Cai, Z.; Bercovici, D.

    2014-12-01

    Partial melting occurs along grain boundaries and migrates through porous flow, leading to magma segregation in the mantle. Solitary porosity waves created by a perturbation in melting have been studied in the flow of a low viscosity fluid in a deformable matrix (McKenzie 1984, Scott and Stevenson 1986, Barcilon and Richter 1986, Spiegelman 1993, Wiggins and Spiegelman 1995). However, in a fairly complicated multi-physics, multi-scale process of magma migration, the geometry and instability of porosity waves can be affected by both mechanical and thermal factors, leaving different propagation signatures. In this work we develop a two-dimensional, two-phase damage model of magma-fracturing, and study the influence of viscosities and damage (void generation and microcracking) on the geometry properties of porosity waves. We first benchmark our solitary solutions with previous works and solve 2-D finite-amplitude waves numerically using spectral and semi-spectral method. We show that damage, decompaction weakening of the matrix and porosity-driven viscosities can alter the geometry of stable porosity waves, and result in an elongated or flattened wave front with a trail of smaller porosity. Such trails may localize subsequent waves and form porosity passage in the matrix. Scaling analysis of the time-dependent porosity waves are conducted and amount of magma reaching to the top of the melting region are estimated. Future work will include evaluating the thermal and seismic signatures during and after melt migration in two-phase porous flow.

  13. Ultrasonic velocities of North Sea chalk samples: influence of porosity, fluid content and texture

    DEFF Research Database (Denmark)

    Rogen, B.; Fabricius, Ida Lykke; Japsen, P.

    2005-01-01

    a porosity-reducing effect and that samples rich in large grains have a relatively low porosity for a given P-wave modulus. The clay content in the samples is low and is mainly represented by either kaolinite or smectite; samples with smectite have a lower P-wave modulus than samples with kaolinite at equal...

  14. Effect of static porosity fluctuations on reactive transport in a porous medium

    Science.gov (United States)

    L'Heureux, Ivan

    2018-02-01

    Reaction-diffusive transport phenomena in porous media are ubiquitous in engineering applications, biological and geochemical systems. The porosity field is usually random in space, but most models consider the porosity field as a well-defined deterministic function of space and time and ignore the porosity fluctuations. They use a reaction-diffusion equation written in terms of an average porosity and average concentration fields. In this contribution, we treat explicitly the effect of spatial porosity fluctuations on the dynamics of a concentration field for the case of a one-dimensional reaction-transport system with nonlinear kinetics. Three basic assumptions are considered. (i) The porosity fluctuations are assumed to have Gaussian properties and an arbitrary variance; (ii) we assume that the noise correlation length is small compared to the relevant macroscopic length scale; (iii) and we assume that the kinetics of the reactive term in the equations for the fluctuations is a self-consistently determined constant. Elimination of the fluctuating part of the concentration field from the dynamics leads to a renormalized equation involving the average concentration field. It is shown that the noise leads to a renormalized (generally smaller) diffusion coefficient and renormalized kinetics. Within the framework of the approximations used, numerical simulations are in agreement with our theory. We show that the porosity fluctuations may have a significant effect on the transport of a reactive species, even in the case of a homogeneous average porosity.

  15. Effect of porosity on the tensile properties of low ductility aluminum alloys

    Directory of Open Access Journals (Sweden)

    Gustavo Waldemar Mugica

    2004-06-01

    Full Text Available The literature contains reports of several studies correlating the porosity and mechanical properties of aluminum alloys. Most of these studies determine this correlation based on the parameter of global volumetric porosity. These reports, however, fail to separate the effects of microstructural features and porosity on alloys, though recognizing the influence of the latter on their mechanical properties. Thus, when the decrease in tensile strength due to the porosity effect is taken into account, the findings are highly contradictory. An analysis was made of the correlation between mechanical properties and global volumetric porosity and volumetric porosity in the fracture, as well as of the beta-Al5FeSi phase present in 380 aluminum alloy. Our findings indicate that mechanical properties in tension relating to global volumetric porosity lead to overestimations of the porosity effect in detriment to the mechanical properties. Moreover, the proposed models that take into account the effects of particles, both Si and beta-Al5FeSi, are unapplicable to low ductility alloys.

  16. 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.

  17. Influence of blast furnace gas flow speed on dust deposition characteristics in butterfly valve region

    OpenAIRE

    Lixin WANG; Bin WANG; Fengshan HUANG

    2016-01-01

    The blast furnace gas contains plenty of dust, which deposits easily on the bottom of seat sealing surface of the tri-eccentric butterfly valve in the pipeline, causing stuck and damage to the valve plate, thereby affects the production of the blast furnace and brings great economic loss. To derive the influence mechanism of effects of the blast furnace gas flow speed within the pipeline on the dust deposition laws in the butterfly valve region, a 3D model of the butterfly valve and its regio...

  18. Radiative models for the furnace side of a bottom-fired reformer

    Energy Technology Data Exchange (ETDEWEB)

    Farhadi, F. [Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran 11365-9465 (Iran, Islamic Republic of)]. E-mail: farhadi@sharif.edu; Bahrami Babaheidari, M. [Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran 11365-9465 (Iran, Islamic Republic of); Motamed Hashemi, M.M.Y. [Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran 11365-9465 (Iran, Islamic Republic of)

    2005-10-01

    Two different groups of radiative models are used to simulate a Midrex reformer. The modeling includes the furnace-side as well as the reactor-side equations. The simultaneous solution of governing equations provides the flue gas and tube wall temperature profiles. These are compared with literature and plant data. It was observed that the Flux model, applied in this work on the furnace of a bottom-fired reformer, shows a good agreement with observed plant data. The well-stirred model is still satisfactory but the long-furnace model is far away to merit an attention.

  19. Experimental study on combustion of biomass micron fuel (BMF) in cyclone furnace

    Energy Technology Data Exchange (ETDEWEB)

    Luo Siyi, E-mail: xiaobo1958@126.co [School of Environmental Science and Engineering, Huanzhong University of Science and Technology, Wuhan 430074 (China); Xiao Bo; Hu Zhiquan; Liu Shiming; He Maoyun [School of Environmental Science and Engineering, Huanzhong University of Science and Technology, Wuhan 430074 (China)

    2010-11-15

    Based on biomass micron fuel (BMF) with particle size less than 250 {mu}m, a cyclone combustion concept was presented and a lab-scale cyclone furnace was designed to evaluate the feasibility. The influences of equivalence ration (ER) and particle size of BMF on combustion performance were studied, as well as temperature distribution in the combustion chamber. The results show that BMF combustion in the cyclone furnace is reliable, with rational temperature distribution inside furnace hearth, lower CO emission, soot concentration and C content in ashes. As ER being 1.2, the temperature in the chamber is maximized up to 1200 deg. C. Smaller particles results in better combustion performances.

  20. Experimental study on combustion of biomass micron fuel (BMF) in cyclone furnace

    Energy Technology Data Exchange (ETDEWEB)

    Siyi Luo; Bo Xiao; Zhiquan Hu; Shiming Liu; Maoyun He [School of Environmental Science and Engineering, Huanzhong University of Science and Technology, Wuhan 430074 (China)

    2010-11-15

    Based on biomass micron fuel (BMF) with particle size less than 250 {mu}m, a cyclone combustion concept was presented and a lab-scale cyclone furnace was designed to evaluate the feasibility. The influences of equivalence ration (ER) and particle size of BMF on combustion performance were studied, as well as temperature distribution in the combustion chamber. The results show that BMF combustion in the cyclone furnace is reliable, with rational temperature distribution inside furnace hearth, lower CO emission, soot concentration and C content in ashes. As ER being 1.2, the temperature in the chamber is maximized up to 1200 C. Smaller particles results in better combustion performances. (author)

  1. Optimization of an aluminium melting furnace using numerical simulations; Optimierung eines Aluminiumschmelzofens mittels numerischer Simulationen

    Energy Technology Data Exchange (ETDEWEB)

    Wittenschlaeger, Thomas; Degen, Dominik; Uhlig, Volker; Trimis, Dimosthenis [Technische Univ. Bergakademie Freiberg (Germany). Inst. fuer Waermetechnik und Thermodynamik; Reimann, Tim; Eigenfeld, Klaus [Technische Univ. Bergakademie Freiberg (Germany). Giesserei-Inst.; Mohammadifard, Zahra; Vieregge, Tobias; Behrens, Bernd-Arno [Leibniz Univ. Hannover, Garbsen (Germany). Inst. fuer Umformtechnik und Umformmaschinen

    2013-09-15

    The effort to develop a new type of industrial furnace can be reduced by the use of numerical simulation tools. This article describes numerical studies of the flow and temperature distributions in an aluminium melding furnace. The aim of the studies is the increase of efficiency of furnace operation by shortening the time span for melding the inserted material. After validating the numerical model, the influence of the level of liquid aluminium on the temperature of the flue gas was studied. Further simulations were carried out to check the influence of a rotation of the burner on the temperature distribution on the melting bridge. (orig.)

  2. A Comparison Study of the Oxygen-Rich Side Blow Furnace and the Oxygen-Rich Bottom Blow Furnace for Liquid High Lead Slag Reduction

    Science.gov (United States)

    Chen, Lin; Hao, Zhandong; Yang, Tianzu; Liu, Weifeng; Zhang, Duchao; Zhang, Li; Bin, Shu; Bin, Wanda

    2015-05-01

    This work investigates the characteristics of the oxygen-rich side blow furnace (OSBF) and the oxygen-rich bottom blow furnace (OBBF) as the reductive smelting reactor for molten high lead slag. The slags were collected from different sampling points of these furnaces during a regular high lead slag reduction process and analyzed. It is disclosed that lead content of the melt in the OSBF shows dramatic fluctuations, while melt from different sampling points of the furnace behave similarly, exhibiting the characteristics of batch reactor. An obvious axial lead content gradient is detected in the OBBF, showing the characteristics of a plug flow reactor. The industrial performances of these furnaces are also compared. The results indicate that 1.38% higher lead recovery can be achieved by using the OSBF instead of the OBBF. Unit energy consumptions of the OBBF-OSBF and OBBF-OBBF processes can be reduced to 230 kgce/ t crude lead, which is 70 kgce/ t crude lead less than that of the tradition Shuikoushan (SKS) process.

  3. Predicting Frost Resistance of Concrete with Different Coarse Aggregate Concentration by Porosity Parameters

    Directory of Open Access Journals (Sweden)

    Džigita NAGROCKIENĖ

    2011-07-01

    Full Text Available Frost resistance is one of the key indicators of concrete quality. Frost resistance can be determined by direct testing; however it is time-consuming and labour-intensive method. Concrete decomposition is a complex process (from initial signs of degradation to complete failure of the surface subjected to freezing involving many factors. Frost resistance of concrete can be predicted from porosity parameters after determining their relation to frost resistance. Test results showed the relation between the closed porosity of concrete and frost resistance factor. Closed porosity of concrete was found to have a significant influence on frost resistance factor. It is shown that closed porosity depends on the concentration of coarse aggregate in concrete, the closed porosity and predicted frost resistance of concrete increase with lower concentration of coarse aggregate.http://dx.doi.org/10.5755/j01.ms.17.2.493

  4. Evolution of porosity and diffusivity associated with chemical weathering of a basalt clast

    Energy Technology Data Exchange (ETDEWEB)

    Navarre-Sitchler, A.; Steefel, C.I.; Yang, L.; Tomutsa, L.; Brantley, S.L.

    2009-02-15

    Weathering of rocks as a result of exposure to water and the atmosphere can cause significant changes in their chemistry and porosity. In low-porosity rocks, such as basalts, changes in porosity, resulting from chemical weathering, are likely to modify the rock's effective diffusivity and permeability, affecting the rate of solute transport and thus potentially the rate of overall weathering to the extent that transport is the rate limiting step. Changes in total porosity as a result of mineral dissolution and precipitation have typically been used to calculate effective diffusion coefficients through Archie's law for reactive transport simulations of chemical weathering, but this approach fails to account for unconnected porosity that does not contribute to transport. In this study, we combine synchrotron X-ray microcomputed tomography ({mu}CT) and laboratory and numerical diffusion experiments to examine changes in both total and effective porosity and effective diffusion coefficients across a weathering interface in a weathered basalt clast from Costa Rica. The {mu}CT data indicate that below a critical value of {approx}9%, the porosity is largely unconnected in the basalt clast. The {mu}CT data were further used to construct a numerical pore network model to determine upscaled, effective diffusivities as a function of total porosity (ranging from 3 to 30%) for comparison with diffusivities determined in laboratory tracer experiments. By using effective porosity as the scaling parameter and accounting for critical porosity, a model is developed that accurately predicts continuum-scale effective diffusivities across the weathering interface of the basalt clast.

  5. Visualizing bone porosities using a tabletop scanning electron microscope

    Science.gov (United States)

    Krishnamoorthy, D.; DaPonte, J.; Broadbridge, C. C.; Daniel, D.; Alter, L.

    2010-04-01

    Pores are naturally occurring entities in bone. Changes in pore size and number are often associated with diseases such as Osteoporosis and even microgravity during spaceflight. Studying bone perforations may yield great insight into bone's material properties, including bone density and may contribute to identifying therapies to halt or potentially reverse bone loss. Current technologies used in this field include nuclear magnetic resonance, micro-computed tomography and the field emission scanning electron microscope (FE-SEM) 2, 5. However, limitations in each method limit further advancement. The objective of this study was to assess the effectiveness of using a new generation of analytical instruments, the TM-1000 tabletop, SEM with back-scatter electron (BSE) detector, to analyze cortical bone porosities. Hind limb unloaded and age-based controlled mouse femurs were extracted and tested in vitro for changes in pores on the periosteal surface. An important advantage of using the tabletop is the simplified sample preparation that excludes extra coatings, dehydration and fixation steps that are otherwise required for conventional SEM. For quantitative data, pores were treated as particles in order to use an analyze particles feature in the NIH ImageJ software. Several image-processing techniques for background smoothing, thresholding and filtering were employed to produce a binary image suitable for particle analysis. It was hypothesized that the unloaded bones would show an increase in pore area, as the lack of mechanical loading would affect bone-remodeling processes taking place in and around pores. Preliminary results suggest only a slight different in frequency but not in size of pores between unloaded and control femurs.

  6. 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).

  7. BLAST FURNACE GRANULAR COAL INJECTION SYSTEM. Final Report Volume 2: Project Performance and Economics

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    1999-10-01

    Bethlehem Steel Corporation (BSC) requested financial assistance from the Department of Energy (DOE), for the design, construction and operation of a 2,800-ton-per-day blast furnace granulated coal injection (BFGCI) system for two existing iron-making blast furnaces. The blast furnaces are located at BSC's facilities in Burns Harbor, Indiana. The demonstration project proposal was selected by the DOE and awarded to Bethlehem in November 1990. The design of the project was completed in December 1993 and construction was completed in January 1995. The equipment startup period continued to November 1995 at which time the operating and testing program began. The blast furnace test program with different injected coals was completed in December 1998.

  8. Coprecipitation Technique for Preconcentration of Some Metal Ions prior to Graphite Furnace Atomic Absorption Spectrometric Determination

    OpenAIRE

    上田, 穣一

    1998-01-01

    Summary-for the preconcentration of trace ions in the graphite furnace atomic absorption spectrometric determination (GFAAS), a rapid and simple coprecipitation method which does not need the filtration

  9. 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.

  10. Accuracy Assessment Points for Hopewell Furnace National Historic Site Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — This shapefile includes the accuracy assessment points used to assess the alliance-level vegetation map of Hopewell Furnace National Historic Site (HOFU) developed...

  11. The development of a high efficiency crucible furnace for aluminium melting

    Energy Technology Data Exchange (ETDEWEB)

    Byabagambi, C.A.; Tucker, R.J.; Waddington, J.D.; Wharmby, D. (British Gas plc, Research and Technology, Solihull (GB))

    1990-05-04

    This paper describes a project undertaken by British Gas to develop a high thermal efficiency crucible furnace for the melting of aluminium and other metals for the diecasting and foundry industries. (author).

  12. Contamination-free graphene by chemical vapor deposition in quartz furnaces

    National Research Council Canada - National Science Library

    Nicola Lisi; Theodoros Dikonimos; Francesco Buonocore; Martina Pittori; Raffaello Mazzaro; Rita Rizzoli; Sergio Marras; Andrea Capasso

    2017-01-01

    .... When graphene is grown in quartz furnaces, in particular, it is common to end up with samples contaminated by heterogeneous particles, which alter the growth mechanism and affect graphene’s properties...

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

    Directory of Open Access Journals (Sweden)

    Victor Bridi Telles

    2013-03-01

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

  14. Process Modeling and Optimization of a Submerged Arc Furnace for Phosphorus Production

    NARCIS (Netherlands)

    Scheepers, E.; Yang, Y.; Adema, A.T.; Boom, R.; Reuter, M.A.

    2010-01-01

    This article presents a process model of a phosphorus-producing, submerged arc furnace. The model successfully incorporates accurate, multifield thermodynamic, kinetic, and industrial data with computational flow dynamic calculations and thus further unifies the sciences of kinetics and equilibrium

  15. Mathematical Modeling of the Melting Rate of Metallic Particles in the Electric Arc Furnace

    National Research Council Canada - National Science Library

    González, O. J. P; Ramírez-Argáez, Marco A; Conejo, A. N

    2010-01-01

    A computational fluid dynamics model coupled to a lagrangian model of melting/solidifying particles has been developed to describe the melting kinetics of metallic particles in an industrial Electric Arc Furnace (EAF...

  16. Preliminary control system design and analysis for the Space Station Furnace Facility thermal control system

    Science.gov (United States)

    Jackson, M. E.

    1995-01-01

    This report presents the Space Station Furnace Facility (SSFF) thermal control system (TCS) preliminary control system design and analysis. The SSFF provides the necessary core systems to operate various materials processing furnaces. The TCS is defined as one of the core systems, and its function is to collect excess heat from furnaces and to provide precise cold temperature control of components and of certain furnace zones. Physical interconnection of parallel thermal control subsystems through a common pump implies the description of the TCS by coupled nonlinear differential equations in pressure and flow. This report formulates the system equations and develops the controllers that cause the interconnected subsystems to satisfy flow rate tracking requirements. Extensive digital simulation results are presented to show the flow rate tracking performance.

  17. Color Infrared Orthorectified Photomosaic for Hopewell Furnace National Historic Site Vegetation Mapping Project

    Data.gov (United States)

    National Park Service, Department of the Interior — Orthorectified color infrared ERDAS Imagine image of Hopewell Furnace NHS. Produced from 37 color infrared photos taken April 4, 2002. Orthorectification...

  18. Conceptual design and economic analysis of a solar metal melting furnace

    Energy Technology Data Exchange (ETDEWEB)

    Sungu, S.; Villacorta, E.H.

    1983-06-01

    This paper presents the conceptual design, construction details, economic analysis of a solar metal melting furnace consisting of multiple axi-symmetrical paraboloids. An axi-symmetric telescoping arrangement was chosen because it does allow the receiver (the metal melting crucible) to be located at the lower end of the paraboloids. In this position the crucible faces the sun, and is readily accessible from the ground. By this choice, the handling of the molten metal is made easier and safer. The solar furnace is designed and sized to melt 10 kg of aluminum per hour. Three concentric paraboloid sections of the furnace are mounted on a platform which tracks the sun by a simple and reliable solar tracking system. The economic analysis shows that the proposed solar metal melting furnace is cost effective and suitable for small batch high purity metal melting.

  19. PROCESSES OF LIQUID-PHASE RECOVERY OF SCALE IN ROTATIONAL FURNACE

    Directory of Open Access Journals (Sweden)

    S. L. Rovin

    2012-01-01

    Full Text Available The data, enabling to establish peculiarities and distinction of liquid-phase reduction of oxides in rotation furnaces, are received as a result of laboratory and field observations.

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

    Directory of Open Access Journals (Sweden)

    M. A. Murikov

    2008-01-01

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

  1. Effect of Matrix-Wellbore Flow and Porosity on Pressure Transient Response in Shale Formation Modeling by Dual Porosity and Dual Permeability System

    Directory of Open Access Journals (Sweden)

    Daolun Li

    2015-01-01

    Full Text Available A mathematical dual porosity and dual permeability numerical model based on perpendicular bisection (PEBI grid is developed to describe gas flow behaviors in shale-gas reservoirs by incorporating slippage corrected permeability and adsorbed gas effect. Parametric studies are conducted for a horizontal well with multiple infinite conductivity hydraulic fractures in shale-gas reservoir to investigate effect of matrix-wellbore flow, natural fracture porosity, and matrix porosity. We find that the ratio of fracture permeability to matrix permeability approximately decides the bottom hole pressure (BHP error caused by omitting the flow between matrix and wellbore and that the effect of matrix porosity on BHP is related to adsorption gas content. When adsorbed gas accounts for large proportion of the total gas storage in shale formation, matrix porosity only has a very small effect on BHP. Otherwise, it has obvious influence. This paper can help us understand the complex pressure transient response due to existence of the adsorbed gas and help petroleum engineers to interpret the field data better.

  2. On the Use of Pre-reduced Feed in the Blast Furnace Process

    Science.gov (United States)

    Gibson, Jorge L.

    In the iron and steel industry, the partial replacement of coke with natural gas as a fuel for blast furnace ironmaking provides opportunities to blast furnace operators, in a context where natural gas is relatively cheap, to reduce greenhouse gas emissions and production costs. Direct injection of natural gas through the blast furnace tuyeres is limited by thermal constraints, seen by changes in the temperature of the top gas and the raceway adiabatic flame temperature parameter. Metallic iron has been used as burden material in the blast furnace process as a means to lower coke rate and increase productivity. The main "direct reduction processes" produce metallic iron by gaseous reduction using natural gas as feedstock. It is possible to partially circumvent the limitations of tuyere injection by pre-reducing part of the iron ore burden through one of these processes. This work focuses on the advantages and limitations of introducing direct reduced iron (DRI) of varying levels of metallization into the blast furnace to increase the use of natural gas in ironmaking. Process modeling has been used to evaluate this; parameters for the models and process constraints are analyzed through laboratory testing of the properties of reduced blast furnace feed materials. Experiments were performed to obtain kinetics for the gaseous reduction of iron ores and for the water-gas shift reaction at the relevant temperatures for the shaft furnace process. The re-oxidation kinetics of DRI in the upper shaft of the blast furnace by water vapor, and the strength of partially reduced iron ore pellets, were also analyzed. Results from the shaft furnace model show that there is no clear benefit to producing DRI of low metallization in this process, because of the existence of a chemical reserve zone, where the gases are at equilibrium with the solid iron oxide. Blast furnace modeling shows that metallic iron in the burden produces some thermal constraints in the blast furnace, and

  3. Saving energy through improving convection in a muffle furnace

    Directory of Open Access Journals (Sweden)

    Minea Adriana Alina

    2008-01-01

    Full Text Available Incompressible forced convection heat transfer problems normally admit an extremely important simplification: the fluid flow problem can be solved without reference to the temperature distribution in the fluid. Thus, it can first find the velocity distribution and then put it in the energy equation as known information and solve for the temperature distribution. In this paper it is intended to expand the theoretic researches concerning heat processes intensification and their use in industrial practice. In conclusion the fundamental research with concrete technical applications represents a significant contribution to the development of knowledge in domain. By centralizing the experimental results, there can be said that there has been obtained an energetic saving of approximate 20% by using radiant panels. By fitting the experimental data there has been obtained an optimum of the panels' positioning of x = 118.71 mm. In conclusion, changing the working space by introducing some radiant panels inside the furnace leads to important energy savings in the heating process, by increasing the heating rate of charge and by decreasing its residence time in the thermal equipment.

  4. Enriching blast furnace gas by removing carbon dioxide.

    Science.gov (United States)

    Zhang, Chongmin; Sun, Zhimin; Chen, Shuwen; Wang, Baohai

    2013-12-01

    Blast furnace gas (BF gas) produced in the iron making process is an essential energy resource for a steel making work. As compared with coke oven gas, the caloric value of BF gas is too low to be used alone as fuel in hot stove because of its high concentrations of carbon dioxide and nitrogen. If the carbon dioxide in BF gas could be captured efficiently, it would meet the increasing need of high caloric BF gas, and develop methods to reusing and/or recycling the separated carbon dioxide further. Focused on this, investigations were done with simple evaluation on possible methods of removing carbon dioxide from BF gas and basic experiments on carbon dioxide capture by chemical absorption. The experimental results showed that in 100 minutes, the maximum absorbed doses of carbon dioxide reached 20 g/100 g with ionic liquid as absorbent. Copyright © 2013 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  5. Phosphorus removal by electric arc furnace steel slag adsorption

    Science.gov (United States)

    Lim, J. W.; Lee, K. F.; Chong, Thomas S. Y.; Abdullah, L. C.; Razak, M. A.; Tezara, C.

    2017-10-01

    As to overcome the eutrophication in lakes and reservoirs which is resulted from excessive input of phosphorus due to rapid urbanization or uncontrolled agricultural activities, Electric Arc Furnace steel slag (EAFS), a steelmaking by-product, in which the disposal of this industrial waste considered economically unfavourable yet it’s physical and chemical properties exhibits high potential to be great P adsorbent. The objective of this study was to identify most suitable mathematical model in description of adsorption by using traditional batch experiment and to investigate the effect on Phosphorus removal efficiency and Phosphorus removal capacity by EAFS adsorption through variation of parameters such as pH, size of slag and initial concentration of Phosphorus. Result demonstrated that, Langmuir is suitable in describing Phosphorus removal mechanisms with the Maximum Adsorption Capacity, Q m of 0.166 mg/g and Langmuir Constant, KL of 0.03519 L/mg. As for effect studies, smaller size of adsorbent shows higher percentage (up to 37.8%) of Phosphorus removal compared to the larger size. Besides that, the experiment indicated a more acidic environment is favourable for Phosphorus removal and the amount of Phosphorus adsorbed at pH 3.0 was the highest. In addition, the adsorption capacity increases steadily as the initial Phosphorus concentration increases but it remained steady at 100mg P/L. Eventually, this study serves as better understanding on preliminary studies of P removal mechanisms by EAFS.

  6. Evaluation of Retrofit Variable-Speed Furnace Fan Motors

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States); Williamson, J. [Consortium for Advanced Residential Buildings (CARB), Norwalk, CT (United States)

    2014-01-01

    In conjunction with the New York State Energy Research and Development Authority (NYSERDA) and Proctor Engineering Group, Ltd. (PEG), the Consortium for Advanced Residential Buildings (CARB) has evaluated the Concept 3™ replacement motors for residential furnaces. These brushless, permanent magnet (BPM) motors can use much less electricity than their PSC (permanent split capacitor) predecessors. This evaluation focuses on existing homes in the heating-dominated climate of upstate New York with the goals of characterizing field performance and cost effectiveness. The project includes eight homes in and near Syracuse, NY. Tests and monitoring was performed both before and after fan motors were replaced. Results indicate that BPM replacement motors will be most cost effective in HVAC systems with longer run times and relatively low duct static pressures. More dramatic savings are possible if occupants use the fan-only setting when there is no thermal load. There are millions of cold-climate, U.S. homes that meet these criteria, but the savings in most homes tested in this study were modest.

  7. Modelling of turbulent combustion in the blast furnace raceway

    Energy Technology Data Exchange (ETDEWEB)

    Karvinen, R.; Maekiranta, R. [Tampere Univ. (Finland). Energy and Process Engineering

    1996-12-31

    The phenomena concerning coke-gas -suspension and simultaneous combustion of solid coke particles and residual fuel oil in a blast furnace raceway are modelled. The flow field of suspension is predicted by using the two fluid model, which is based on the Eulerian method, in the Phoenics code. The standard k-e -model of turbulence is used. Pyrolysis of oil droplets is calculated with the own coded subroutine, which is based on the Lagrangian approach. Gas phase reaction rate is assumed to be controlled by chemical kinetics. Radiative heat transfer is calculated by using the six-flux method. Heterogenous surface reactions are used for the coke particles. Calculations without coke combustion show that due to a poor mixing in the hot blast, pyrolysis gases of residual fuel oil have not time enough to react with oxygen. It is obvious that if combustion of coke particles is taken into account, the oxygen content in the blast decreases to such a level, that unburnt pyrolysis gases can flow out of the raceway causing problems. The distribution of coke void fraction has been succeeded to predict in the raceway domain. Coke particles fall from the upper part of the raceway to the hot blast forming locally high concentrations, which affect very strongly the oxygen distribution of the hot blast. (orig.) SULA 2 Research Programme; 10 refs.

  8. Thermal Treatment of Solid Wastes Using the Electric Arc Furnace

    Energy Technology Data Exchange (ETDEWEB)

    O' Connor, W.K.; Turner, P.C.

    1999-09-01

    A thermal waste treatment facility has been developed at the Albany Research Center (ARC) over the past seven years to process a wide range of heterogeneous mixed wastes, on a scale of 227 to 907 kg/h (500 to 2,000 lb/h). The current system includes a continuous feed system, a 3-phase AC, 0.8 MW graphite electrode arc furnace, and a dedicated air pollution control system (APCS) which includes a close-coupled thermal oxidizer, spray cooler, baghouse, and wet scrubber. The versatility of the complete system has been demonstrated during 5 continuous melting campaigns, ranging from 11 to 25 mt (12 to 28 st) of treated wastes per campaign, which were conducted on waste materials such as (a) municipal incinerator ash, (b) simulated low-level radioactive, high combustible-bearing mixed wastes, (c) simulated low-level radioactive liquid tank wastes, (d) heavy metal contaminated soils, and (e) organic-contaminated dredging spoils. In all cases, the glass or slag products readily passed the U.S. Environmental Protection Agency (EPA) Toxicity Characteristic Leachability Program (TCLP) test. Additional studies are currently under way on electric utility wastes, steel and aluminum industry wastes, as well as zinc smelter residues. Thermal treatment of these solid waste streams is intended to produce a metallic product along with nonhazardous glass or slag products.

  9. Experimental and numerical studies of rotating drum grate furnace

    Directory of Open Access Journals (Sweden)

    Basista Grzegorz

    2017-01-01

    Full Text Available Waste material from the meat industry can be taken into account as a biofuel. Studies confirm, that calorific value is higher and ash content is lower comparing to some conventional fuels. EU directives regulate details of thermal disposal of the waste material from the meat industry - especially in range of the process temperature and time of the particle presence in area of the combustion zone. The paper describes design of the rotating drum grate stove, dedicated to thermal disposal of the meat wastes as well as solid biomass (pellet, small bricket, wood chips combustion. Device has been developed in frames of cooperation between AGH University of Science and Technology (Krakow, Poland and producer focused on technologies of energy utilization of biomass in distributed generation. Results of measurements of selected operational parameters performed during startup of the furnace have been presented and discussed. Furthermore, numerical model of the combustion process has been developed to complement experimental results in range of the temperature and oxygen distribution in the area of the combustion chamber. ANSYS CFX solver has been applied to perform simulations including rotational domain related with specifics of operation of the device. Results of numerical modelling and experimental studies have been summarized and compared.

  10. Vanadium bioavailability in soils amended with blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Maja A., E-mail: maja.larsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Baken, Stijn, E-mail: stijn.baken@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Smolders, Erik, E-mail: erik.smolders@ees.kuleuven.be [Department of Earth and Environmental Sciences, Leuven University, Kasteelpark Arenberg 20 bus 2459, 3001 Leuven (Belgium); Cubadda, Francesco, E-mail: francesco.cubadda@iss.it [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanità, Viale Regina Elena 299, Rome 00161 (Italy); Gustafsson, Jon Petter, E-mail: jon-petter.gustafsson@slu.se [Department of Soil and Environment, Swedish University of Agricultural Sciences, P.O. Box 7014, 750 07 Uppsala (Sweden); Division of Land and Water Resources Engineering, KTH Royal Institute of Technology, Brinellvägen 28, 100 44 Stockholm (Sweden)

    2015-10-15

    Blast furnace (BF) slags are commonly applied as soil amendments and in road fill material. In Sweden they are also naturally high in vanadium. The aim of this study was to assess the vanadium bioavailability in BF slags when applied to soil. Two soils were amended with up to 29% BF slag (containing 800 mg V kg{sup −1}) and equilibrated outdoors for 10 months before conducting a barley shoot growth assay. Additional soil samples were spiked with dissolved vanadate(V) for which assays were conducted two weeks (freshly spiked) and 10 months (aged) after spiking. The BF slag vanadium was dominated by vanadium(III) as shown by V K-edge XANES spectroscopy. In contrast, results obtained by HPLC-ICP-MS showed that vanadium(V), the most toxic vanadium species, was predominant in the soil solution. Barley shoot growth was not affected by the BF slag additions. This was likely due to limited dissolution of vanadium from the BF slag, preventing an increase of dissolved vanadium above toxic thresholds. The difference in vanadium bioavailability among treatments was explained by the vanadium concentration in the soil solution. It was concluded that the vanadium in BF slag is sparingly available. These findings should be of importance in environmental risk assessment.

  11. Pigment identification in artwork using graphite furnace atomic absorption spectrometry.

    Science.gov (United States)

    Goltz, D M; Coombs, J; Marion, C; Cloutis, E; Gibson, J; Attas, M; Choo-Smith, L-P; Collins, C

    2004-06-17

    The use of a sampling technique is described for the identification of metals from inorganic pigments in paint. The sampling technique involves gently contacting a cotton swab with the painted surface to physically remove a minute quantity ( approximately 1-2mug) of pigment. The amount of material removed from the painted surface is invisible to the unaided eye and does not cause any visible effect to the painted surface. The cotton swab was then placed in a 1.5ml polystyrene beaker containing HNO(3) to extract pigment metals prior to analysis using graphite furnace atomic absorption spectrometry (GFAAS). GFAAS is well suited for identifying pigment metals since it requires small samples and many pigments consist of main group elements (e.g. Al) as well as transition metals (e.g. Zn, Fe and Cd). Using Cd (cadmium red) as the test element, the reproducibility of sampling a paint surface with the cotton swab was approximately 13% in either a water or oil medium. To test the feasibility of cotton sampling for pigment identification, samples were obtained from paintings (watercolour and oil) of a local collection. Raman spectra provided complementary information to the GFAAS, which together are essential for positive identification of some pigments. For example, GFAAS indicated the presence of Cu, but the Raman spectra positively identified the modern copper pigment phthalocyanine green (Cu(C(32)Cl(16)N(8)). Both Raman spectroscopy and GFAAS were useful for identifying ZnO as a white pigment.

  12. Detailed model for practical pulverized coal furnaces and gasifiers

    Energy Technology Data Exchange (ETDEWEB)

    Philips, S.D.; Smoot, L.D.

    1989-08-01

    The need to improve efficiency and reduce pollutant emissions commercial furnaces has prompted energy companies to search for optimized operating conditions and improved designs in their fossil-fuel burning facilities. Historically, companies have relied on the use of empirical correlations and pilot-plant data to make decisions about operating conditions and design changes. The high cost of collecting data makes obtaining large amounts of data infeasible. The main objective of the data book is to provide a single source of detailed three-dimensional combustion and combustion-related data suitable for comprehensive combustion model evaluation. Five tasks were identified as requirements to achieve the main objective. First, identify the types of data needed to evaluate comprehensive combustion models, and establish criteria for selecting the data. Second, identify and document available three-dimensional combustion data related to pulverized coal combustion. Third, collect and evaluate three-dimensional data cases, and select suitable cases based on selection criteria. Fourth, organize the data sets into an easy-to-use format. Fifth, evaluate and interpret the nature and quality of the data base. 39 refs., 15 figs., 14 tabs.

  13. 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

  14. Injection of heavy fuel oil into the blast furnace

    Energy Technology Data Exchange (ETDEWEB)

    Paloposki, T. [Helsinki Univ. of Technology, Otaniemi (Finland); Hakala, J.; Mannila, P.; Laukkanen, J. [Oulu Univ. (Finland)

    1996-12-31

    This study deals with the injection and combustion of heavy fuel oil in blast furnaces. The injection of the oil was studied experimentally in a small-scale test rig. The combustion of the oil was analysed with a commercial computer program for flow and combustion simulations. Results from computer simulations show that the combustion of the oil can be improved by decreasing the size of the oil drops and by enhancing the mixing between the oil drops and the hot blast. The devolatilization rate of the oil mainly depends on the size of the oil drops. The combustion rate of the volatiles mainly depends on the effectiveness of turbulent mixing with combustion air. Methods to decrease the size of the oil drops were sought in the experimental part of the study. Experimental results show that the size of the oil drops increases with increasing mass flow rate of the oil and decreases with increasing velocity of the hot blast. Methods to improve the mixing between the oil drops and the hot blast are suggested but have not yet been experimentally tested. (author) (4 refs.)

  15. 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.

  16. Measurement of diffusion coefficient of liquid metals by using Gradient Heating Furnace in ISS

    OpenAIRE

    Masaki, Tadahiko; Itami, Toshio; Watanabe, Yuki; 正木 匡彦; 伊丹 俊夫; 渡辺 勇基

    2007-01-01

    The experimental techniques for the measurements of diffusion coefficient have been studied in JAXA toward the utilization of microgravity environment in ISS (International Space Station). The experimental cartridge for the gradient heating furnace, GHF (Gradient Heating Furnace), was developed for the application of shear cell which is the advanced technique of diffusion experiments. The temperature profiles of GHF were measured for the diffusion experiments and the isothermal condition can ...

  17. Experiment/facility requirements document for the Space Station Furnace Facility. Section 1: Integrated configuration

    Science.gov (United States)

    1992-01-01

    The function of the Space Station Furnace Facility (SSFF) is to support materials research into the crystal growth and solidification processes of electronic and photonic materials, metals and alloys, and glasses and ceramics. To support this broad base of research requirements, the SSFF will employ a variety of furnace modules which will be operated, regulated, and supported by a core of common subsystems. Furnace modules may be reconfigured or specifically developed to provide unique solidification conditions for each set of experiments. The SSFF modular approach permits the addition of new or scaled-up furnace modules to support the evolution of the facility as new science requirements are identified. The SSFF Core is of modular design to permit augmentation for enhanced capabilities. The fully integrated configuration of the SSFF will consist of three racks with the capability of supporting up to two furnace modules per rack. The initial configuration of the SSFF will consist of two of the three racks and one furnace module. This Experiment/Facility Requirements Document (E/FRD) describes the integrated facility requirements for the Space Station Freedom (SSF) Integrated Configuration-1 (IC1) mission. The IC1 SSFF will consist of two racks: the Core Rack, with the centralized subsystem equipment; and the Experiment Rack-1, with Furnace Module-1 and the distributed subsystem equipment to support the furnace. The SSFF support functions are provided by the following Core subsystems: power conditioning and distribution subsystem (SSFF PCDS); data management subsystem (SSFF DMS); thermal control Subsystem (SSFF TCS); gas distribution subsystem (SSFF GDS); and mechanical structures subsystem (SSFF MSS).

  18. Coke reactivity under blast furnace condition and in the CSR/CRI test

    OpenAIRE

    Lundgren, Maria; Björkman, Bo; Sundqvist Ökvist, Lena

    2008-01-01

    The present work aims to study the high-temperature strength of coke. Mechanisms of disintegration were evaluated using basket samples charged into LKAB's experimental blast furnace prior to quenching and dissection. Coke charged into basket samples were analysed with CSR/CRI tests and compared with treated coke from the blast furnace. Results from tumbling tests, chemical analyses of coarse and fine material, as well as light optical microscopy studies of original and treated coke have been ...

  19. Improvement of calculation method for electrical parameters of short network of ore-thermal furnaces

    Science.gov (United States)

    Aliferov, A. I.; Bikeev, R. A.; Goreva, L. P.

    2017-10-01

    The paper describes a new calculation method for active and inductive resistance of split interleaved current leads packages in ore-thermal electric furnaces. The method is developed on basis of regression analysis of dependencies of active and inductive resistances of the packages on their geometrical parameters, mutual disposition and interleaving pattern. These multi-parametric calculations have been performed with ANSYS software. The proposed method allows solving split current lead electrical parameters minimization and balancing problems for ore-thermal furnaces.

  20. Development of coke properties during the descent in the blast furnace

    OpenAIRE

    Lundgren, Maria

    2013-01-01

    The efficiency in use of reducing agents in blast furnace (BF) ironmaking has been significantly improved over the years. At most blast furnaces, auxiliary fuels are injected to replace some of the coke. To further reduce carbon consumption, prevention of losses and modification of raw materials or process conditions are required. In this study coke properties, their development during the descent in the BF under different process conditions, contribution to off-gas dust as well as modificati...

  1. Furnaces. Manufacturers become engineering offices; Les fours, le constructeur devient bureau d`ingenierie

    Energy Technology Data Exchange (ETDEWEB)

    Nivoche, C. [Salas SA (France)

    1997-12-31

    The example of Selas, a manufacturer of industrial furnaces for steel and glass industries, faced with the new european pollution regulations, is presented. It is shown how Selas has to develop optimal furnaces using low emission burners but also has to be involved in all the related aspects such as industrial implementation in the client`s plant, plant architecture, cooling systems, air conditioning, noise and vibration issues, operation procedures, safety, etc. Means for reducing NOx emissions are reviewed

  2. Expert Meeting Report: Achieving the Best Installed Performance from High-Efficiency Residential Gas Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brand, Larry [Partnership for Advanced Residential Retrofit (PARR), Des Plaines, IL (United States)

    2012-03-01

    This report describes a Building America expert meeting hosted on July 28, 2011, by the Partnership for Advanced Residential Retrofit (PARR) team. The purpose of this meeting was to identify installation practices that provide the best installed efficiency for residential gas furnaces, explain how AFUE and field efficiency can differ, and investigate the impact of installation practices on the efficiency and long-term durability of the furnace.

  3. Expert Meeting Report: Achieving the Best Installed Performance from High-Efficiency Residential Gas Furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Brand, L.

    2012-03-01

    This report describes a Building America expert meeting hosted on July 28, 2011, by the Partnership for Advanced Residential Retrofit team. The purpose of this meeting was to identify installation practices that provide the best installed efficiency for residential gas furnaces, explain how AFUE and field efficiency can differ, and investigate the impact of installation practices on the efficiency and long-term durability of the furnace.

  4. 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

  5. The Effects of Temperature and Pressure on the Porosity Evolution of Flechtinger Sandstone

    Science.gov (United States)

    Hassanzadegan, Alireza; Blöcher, Guido; Milsch, Harald; Urpi, Luca; Zimmermann, Günter

    2014-03-01

    A porosity change influences the transport properties and the elastic moduli of rock while circulating water in a geothermal reservoir. The static and dynamic elastic moduli can be derived from the slope of stress-strain curves and velocity measurements, respectively. Consequently, the acoustic velocities were measured while performing hydrostatic drained tests. The effect of temperature on static and dynamic elastic moduli and porosity variations of Flechtinger sandstone was investigated in a wide range of confining pressure from 2 to 55 MPa. The experiments were carried out in a conventional triaxial system whereas the pore pressure remained constant, confining pressure was cycled, and temperature was increased step wise (25, 60, 90, 120, and 140 °C). The porosity variation was calculated by employing two different theories: poroelasticity and crack closure. The porosity variation and crack porosity were determined by the first derivative of stress-strain curves and the integral of the second derivative of stress-strain curves, respectively. The crack porosity analysis confirms the creation of new cracks at high temperatures. The porosity variation was increasing with an increase in temperature at low effective pressures and was decreasing with a rise in temperature at high effective pressures. Both compressional and shear wave velocities were increasing with increasing pressure due to progressive crack closure. Furthermore, the thermomechanical behavior of Flechtinger sandstone was characterized by an inversion effect where the sign of the temperature derivative of the drained bulk modulus changes.

  6. Examining the influence of heterogeneous porosity fields on conservative solute transport

    Science.gov (United States)

    Hu, B.X.; Meerschaert, M.M.; Barrash, W.; Hyndman, D.W.; He, C.; Li, X.; Guo, Laodong

    2009-01-01

    It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and particle size measurements from boreholes at the Boise Hydrogeophysical Research Site (BHRS) to evaluate the importance of characterizing the spatial structure of porosity and grain size data for solute transport modeling. Then we develop synthetic hydraulic conductivity fields based on relatively simple measurements of porosity from borehole logs and grain size distributions from core samples to examine and compare the characteristics of tracer transport through these fields with and without inclusion of porosity heterogeneity. In particular, we develop horizontal 2D realizations based on data from one of the less heterogeneous units at the BHRS to examine effects where spatial variations in hydraulic parameters are not large. The results indicate that the distributions of porosity and the derived hydraulic conductivity in the study unit resemble fractal normal and lognormal fields respectively. We numerically simulate solute transport in stochastic fields and find that spatial variations in porosity have significant effects on the spread of an injected tracer plume including a significant delay in simulated tracer concentration histories.

  7. Optimization of a Steel Plant with Multiple Blast Furnaces Under Biomass Injection

    Science.gov (United States)

    Wiklund, Carl-Mikael; Pettersson, Frank; Saxén, Henrik

    2013-04-01

    The allocation of resources between several blast furnaces in an integrated steelmaking plant is studied with the aim of finding the lowest specific operation cost for steel production. In order to reduce the use of fossil fuels, biomass was considered as an auxiliary reductant in the furnace after partial pyrolysis in an external unit, as a complement to heavy fuel oil. The optimization considers raw material, energy, and emission costs and a possible credit for sold power and heat. To decrease computational requirements and to guarantee that the global optimum is found, a piecewise linearized model of the blast furnace was used in combination with linear models of the sinter-, coke-, and power plants, hot stoves, and basic oxygen furnace. The optimization was carried out under different constraints on the availability of some raw materials as well as for different efficiencies of the hot stoves of the blast furnaces. The results indicate that a non-uniform distribution of the production between the furnaces can be advantageous, and some surprising findings concerning the optimal resource allocation under constrained operation are reported.

  8. Electric Arc Furnace Modeling with Artificial Neural Networks and Arc Length with Variable Voltage Gradient

    Directory of Open Access Journals (Sweden)

    Raul Garcia-Segura

    2017-09-01

    Full Text Available Electric arc furnaces (EAFs contribute to almost one third of the global steel production. Arc furnaces use a large amount of electrical energy to process scrap or reduced iron and are relevant to study because small improvements in their efficiency account for significant energy savings. Optimal controllers need to be designed and proposed to enhance both process performance and energy consumption. Due to the random and chaotic nature of the electric arcs, neural networks and other soft computing techniques have been used for modeling EAFs. This study proposes a methodology for modeling EAFs that considers the time varying arc length as a relevant input parameter to the arc furnace model. Based on actual voltages and current measurements taken from an arc furnace, it was possible to estimate an arc length suitable for modeling the arc furnace using neural networks. The obtained results show that the model reproduces not only the stable arc conditions but also the unstable arc conditions, which are difficult to identify in a real heat process. The presented model can be applied for the development and testing of control systems to improve furnace energy efficiency and productivity.

  9. NEDO project reports. High performance industrial furnace development project - High temperature air combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-21

    For the purpose of reducing energy consumption, a NEDO project 'Developmental research on high efficiency industrial furnaces' was carried out from FY 1993 to FY 1999 by The Japan Industrial Furnaces Manufacturers Association, and the paper outlined the details of the project. Industrial furnaces handled in this R and D can bring 30% reduction of the energy consumption and approximately 50% NOx reduction, and were given the 9th Nikkei global environmental technology prize. In the study of combustion phenomena of high temperature air combustion, the paper arranged characteristics of flame, the base of gaseous fuel flame, the base of liquid fuel flame, the base of solid fuel flame, etc. Concerning high temperature air combustion models for simulation, fluid dynamics and heat transfer models, and reaction and NOx models, etc. As to impacts of high temperature air combustion on performance of industrial furnaces, energy conservation, lowering of pollution, etc. In relation to a guide for the design of high efficiency industrial furnaces, flow charts, conceptual design, evaluation method for heat balance and efficiency using charts, combustion control system, applicability of high efficiency industrial furnaces, etc. (NEDO)

  10. Optimization of the thermogauge furnace for realizing high temperature fixed points

    Energy Technology Data Exchange (ETDEWEB)

    Wang, T.; Dong, W. [National Institute of Metrology (NIM), Beijing (China); Liu, F. [AVIC China Precision Engineering Institute for Aircraft Industry, Beijing (China)

    2013-09-11

    The thermogauge furnace was commonly used in many NMIs as a blackbody source for calibration of the radiation thermometer. It can also be used for realizing the high temperature fixed point(HTFP). According to our experience, when realizing HTFP we need the furnace provide relative good temperature uniformity to avoid the possible damage to the HTFP. To improve temperature uniformity in the furnace, the furnace tube was machined near the tube ends with a help of a simulation analysis by 'ansys workbench'. Temperature distributions before and after optimization were measured and compared at 1300 °C, 1700°C, 2500 °C, which roughly correspond to Co-C(1324 °C), Pt-C(1738 °C) and Re-C(2474 °C), respectively. The results clearly indicate that through machining the tube the temperature uniformity of the Thermogage furnace can be remarkably improved. A Pt-C high temperature fixed point was realized in the modified Thermogauge furnace subsequently, the plateaus were compared with what obtained using old heater, and the results were presented in this paper.

  11. Optimization of the thermogauge furnace for realizing high temperature fixed points

    Science.gov (United States)

    Wang, T.; Dong, W.; Liu, F.

    2013-09-01

    The thermogauge furnace was commonly used in many NMIs as a blackbody source for calibration of the radiation thermometer. It can also be used for realizing the high temperature fixed point(HTFP). According to our experience, when realizing HTFP we need the furnace provide relative good temperature uniformity to avoid the possible damage to the HTFP. To improve temperature uniformity in the furnace, the furnace tube was machined near the tube ends with a help of a simulation analysis by "ansys workbench". Temperature distributions before and after optimization were measured and compared at 1300 °C, 1700°C, 2500 °C, which roughly correspond to Co-C(1324 °C), Pt-C(1738 °C) and Re-C(2474 °C), respectively. The results clearly indicate that through machining the tube the temperature uniformity of the Thermogage furnace can be remarkably improved. A Pt-C high temperature fixed point was realized in the modified Thermogauge furnace subsequently, the plateaus were compared with what obtained using old heater, and the results were presented in this paper.

  12. Development of charge calculation program for target steel in induction furnace

    Directory of Open Access Journals (Sweden)

    Saliu O. SEIDU

    2015-12-01

    Full Text Available This paper presents the development of charge calculation program for target steel in induction furnace. The simulation modelling function developed is based on mass balance analysis of the furnace production. The process engineering of the furnace follows linear algebraic mathematical function. Visual basic programming language (C# is used in the coding and interface integration. This is used to develop a unit process based simulation program with user friendly interface for the furnace. The application could be adapted to the production of different alloy steel depending on the production standard set by the user. Also, the program is developed to calculate the mass of scrap for optimization, ferrosilicon, ferromanganese, and other additives. Iteration of scrap charge for optimization is incorporated to enable the user simulates changes and manipulates scrap charge in the furnace before ferro-alloys and carbon additives are charged depending on the foundry practice or target standard. This also helps in the decision of the furnace engineer while requesting scrap from the yard. On validation, the program was seen to give charge optimization result very close in value to standard charge rate of the integrated steel complex in which it was tested.

  13. Wave propagation speeds and source term influences in single and integral porosity shallow water equations

    Directory of Open Access Journals (Sweden)

    Ilhan Özgen

    2017-10-01

    Full Text Available In urban flood modeling, so-called porosity shallow water equations (PSWEs, which conceptually account for unresolved structures, e.g., buildings, are a promising approach to addressing high CPU times associated with state-of-the-art explicit numerical methods. The PSWE can be formulated with a single porosity term, referred to as the single porosity shallow water model (SP model, which accounts for both the reduced storage in the cell and the reduced conveyance, or with two porosity terms: one accounting for the reduced storage in the cell and another accounting for the reduced conveyance. The latter form is referred to as an integral or anisotropic porosity shallow water model (AP model. The aim of this study was to analyze the differences in wave propagation speeds of the SP model and the AP model and the implications of numerical model results. First, augmented Roe-type solutions were used to assess the influence of the source terms appearing in both models. It is shown that different source terms have different influences on the stability of the models. Second, four computational test cases were presented and the numerical models were compared. It is observed in the eigenvalue-based analysis as well as in the computational test cases that the models converge if the conveyance porosity in the AP model is close to the storage porosity. If the porosity values differ significantly, the AP model yields different wave propagation speeds and numerical fluxes from those of the BP model. In this study, the ratio between the conveyance and storage porosities was determined to be the most significant parameter.

  14. Genetic susceptibility of periodontitis

    NARCIS (Netherlands)

    Laine, M.L.; Crielaard, W.; Loos, B.G.

    2012-01-01

    In this systematic review, we explore and summarize the peer-reviewed literature on putative genetic risk factors for susceptibility to aggressive and chronic periodontitis. A comprehensive literature search on the PubMed database was performed using the keywords ‘periodontitis’ or ‘periodontal

  15. Fourie susceptible.pmd

    African Journals Online (AJOL)

    Prof. Adipala Ekwamu

    a number of cultivars exhibited field resistance to halo blight and bacterial brown spot, all cultivars were more or less susceptible to .... Cerillos. Alubia. I. 91. 57. Kranskop. Red speckled sugar. II. 97. 63. OPS-RS1. Red speckled sugar. II. 96. 63. OPS-RS2. Red speckled sugar. I. 100. 61. OPS-RS3. Red speckled sugar. II. 97.

  16. Dual control of flow field heterogeneity and immobile porosity on non‐Fickian transport in Berea sandstone

    National Research Council Canada - National Science Library

    Gjetvaj, Filip; Russian, Anna; Gouze, Philippe; Dentz, Marco

    2015-01-01

    ...) and diffusion in the microporous phase (immobile domain) where the effective diffusion coefficient is calculated from the measured local porosity using a phenomenological model that includes a porosity threshold ( ϕ θ...

  17. Permeability, porosity and compressive strength of self-compacting concrete

    Directory of Open Access Journals (Sweden)

    Valcuende, M.O.

    2005-12-01

    Full Text Available Most deterioration affecting the durability of self-compacting concrete structures is mediated by water penetration in the concrete, a condition related to its porous structure. The present study analyzes these two factors. To this end, two types of concrete were prepared, a self-compacting and a traditional vibrated concrete, with different W/C ratios and different types of cement. The results of low-pressure water testing to evaluate permeability and analyses to determine compressive strength and pore size distribution showed that self-compacting concrete has lower capillary porosity than traditional concrete, which would explain its greater resistance to water penetration. Such concrete likewise reached higher strength values, except where large proportions of lime powder with low sand equivalents were used in its manufacture, when lower strength was recorded. Lastly, the depth of water penetration and compressive strength were found to be linearly correlated. That correlation was seen to depend, in turn, on the type of concrete, since for any given strength level, self-compacting concrete was less permeable than the traditional material.

    En este trabajo experimental se estudia la penetración de agua en hormigones autocompactables, analizando al mismo tiempo su estructura porosa, pues gran parte de los procesos de deterioro que afectan a la durabilidad de las estructuras están condicionados por estos dos aspectos. Para ello se han fabricado dos tipos de hormigones, uno autocompactable y otro tradicional vibrado, con diferentes relaciones A/C y distintos tipos de cemento. Tras determinar la permeabilidad al agua bajo presión, la resistencia a compresión y las distribuciones de tamaño de poro, los resultados obtenidos ponen de manifiesto que los hormigones autocompactables presentan menor porosidad capilar que los tradicionales, lo que les confiere mejores prestaciones frente a la penetración de agua. Asimismo, dichos hormigones

  18. Feasibility of optimizing trimetazidine dihydrochloride release from controlled porosity

    Directory of Open Access Journals (Sweden)

    Basant A. Habib

    2014-05-01

    Full Text Available The aim of this study was to develop and optimize Trimetazidine dihydrochloride (TM controlled porosity osmotic pump (CPOP tablets of directly compressed cores. A 23 full factorial design was used to study the influence of three factors namely: PEG400 (10% and 25% based on coating polymer weight, coating level (10% and 20% of tablet core weight and hole diameter (0 “no hole” and 1 mm. Other variables such as tablet cores, coating mixture of ethylcellulose (4% and dibutylphthalate (2% in 95% ethanol and pan coating conditions were kept constant. The responses studied (Yi were cumulative percentage released after 2 h (Q%2h, 6 h (Q%6h, 12 h (Q%12h and regression coefficient of release data fitted to zero order equation (RSQzero, for Y1, Y2, Y3, and Y4, respectively. Polynomial equations were used to study the influence of different factors on each response individually. Response surface methodology and multiple response optimization were used to search for an optimized formula. Response variables for the optimized formula were restricted to 10% ⩽ Y1 ⩽ 20%, 40% ⩽ Y2 ⩽ 60%, 80% ⩽ Y3 ⩽ 100%, and Y4 > 0.9. The statistical analysis of the results revealed that PEG400 had positive effects on Q%2h, Q%6h and Q%12h, hole diameter had positive effects on all responses and coating level had positive effect on Q%6h, Q%12h and negative effect on RSQzero. Full three factor interaction (3FI equations were used for representation of all responses except Q%2h which was represented by reduced (3FI equation. Upon exploring the experimental space, no formula in the tested range could satisfy the required constraints. Thus, direct compression of TM cores was not suitable for formation of CPOP tablets. Preliminary trials of CPOP tablets with wet granulated cores were promising with an intact membrane for 12 h and high RSQzero. Further improvement of these formulations to optimize TM release will be done in further studies.

  19. Controlling the porosity of powder metallurgy products by a laser beam

    Energy Technology Data Exchange (ETDEWEB)

    Uglov, A.A.; Grebennikov, V.A.; Panaetov, V.G.; Ignatev, M.B.

    1986-08-01

    Experimental results obtained for powder metallurgy products based on nickel, bronze, and molybdenum are used to establish a relationship between the porosity of a material and the parameters of the beam-affected zone and also between the characteristics of a laser erosion plasma. The approach proposed here makes it possible to control the porosity of powder metallurgy alloys in the porosity range 0-60 percent for products based on high-melting powders and in the range 0-25 percent for products based on metals with a melting temperature below 2000 C. 9 references.

  20. Evidence of second order transition induced by the porosity in the thermal conductivity of sintered metals

    Directory of Open Access Journals (Sweden)

    Aïmen E. Gheribi

    2014-07-01

    Full Text Available In this paper, using both experimental data and theoretical modelling, we investigate the degradation of the thermal conductivity of sintered metals due simultaneously to the grain boundary thermal resistance and the porosity. We show that the porosity dependence of the thermal conductivity of sintered material from spherical particle powder, exhibits a critical behaviour associated with a second order phase transition. An analytical model with a single parameter is proposed to describe the critical behaviour of the thermal conductivity of sintered metals versus porosity.

  1. Oxygen plasma treatment of HKUST-1 for porosity retention upon exposure to moisture.

    Science.gov (United States)

    Bae, Jaeyeon; Jung, Jin-Woo; Park, Hyo Yul; Cho, Chang-Hee; Park, Jinhee

    2017-10-26

    Despite their remarkable properties, metal-organic frameworks (MOFs) present vulnerable structures that are sensitive to moisture; therefore, their application to real field situations is challenging. Herein, an O2 plasma technique was introduced as a new method for the activation and protection of porosity in HKUST-1. In an unprecedented manner, O2 plasma-treated HKUST-1 retains its porosity after a long exposure to moisture as compared to pristine HKUST-1. Porosity retention was examined by N2 adsorption/desorption measurements of non-activated HKUST-1 after exposure to moisture.

  2. Furnace and Heat Recovery Area Design and Analysis for Conceptual Design of Oxygen-Based PC Boiler

    Energy Technology Data Exchange (ETDEWEB)

    Andrew Seltzer

    2005-01-01

    The objective of the furnace and heat recovery area design and analysis task of the Conceptual Design of Oxygen-Based PC Boiler study is to optimize the location and design of the furnace, burners, over-fire gas ports, and internal radiant surfaces. The furnace and heat recovery area were designed and analyzed using the FW-FIRE and HEATEX computer programs. The furnace is designed with opposed wall-firing burners and over-fire air ports. Water is circulated in the furnace by natural circulation to the waterwalls and divisional wall panels. Compared to the air-fired furnace, the oxygen-fired furnace requires only 65% of the surface area and 45% of the volume. Two oxygen-fired designs were simulated: (1) without over-fire air and (2) with 20% over-fire air. The maximum wall heat flux in the oxygen-fired furnace is more than double that of the air-fired furnace due to the higher flame temperature and higher H{sub 2}O and CO{sub 2} concentrations. The coal burnout for the oxygen-fired case is 100% due to a 500 F higher furnace temperature and higher concentration of O{sub 2}. Because of the higher furnace wall temperature of the oxygen-fired case compared to the air-fired case, furnace water wall material was upgraded from carbon steel to T91. The total heat transfer surface required in the oxygen-fired heat recovery area (HRA) is 25% less than the air-fired HRA due to more heat being absorbed in the oxygen-fired furnace and the greater molecular weight of the oxygen-fired flue gas. The HRA tube materials and wall thickness are practically the same for the air-fired and oxygen-fired design since the flue gas and water/steam temperature profiles encountered by the heat transfer banks are very similar.

  3. Glassceramics from Industrial Waste Prepared in a Microwave Furnace

    Directory of Open Access Journals (Sweden)

    Milota Kováčová

    2012-12-01

    Full Text Available This work presents the study of glassceramics from nickel leaching residue used as a heavy metal carrier (Cd, Pb preparedby microwave vitrification. The Vicker`s microhardness, chemical durability and magnetic susceptibility of vitrified waste was tested.The glassceramics containing 40-50 % of nickel leaching residue with a high microhardness and very good chemical durability wasobtained in a short time of heating (45 minutes.

  4. Improvement of the Rotary Dryers of Wet Pelletized Oil-Furnace Carbon Blacks

    Directory of Open Access Journals (Sweden)

    Zečević, M

    2010-05-01

    Full Text Available Due to the demand for higher production capacity and natural-gas energy savings, improvements were made to the rotary dryers in the drying process of wet pelletized oil-furnace carbon blacks. Since the rotary dryers were originally designed for drying semi-wet pelletized oil-furnace carbon blacks, they did not entirely satisfy optimal conditions for drying wet pelletized oil-furnace carbon blacks. Figure 1 shows the drying principle with key dimensions. The energy for drying the wet pelletized oil-furnace carbon blacks was provided by natural gas combustion in an open-furnace system with an uncontrolled feed of combustion air. Improvements on the rotary dryers were carried out by adjusting the excess oxygen in the gases passing through the butterfly valve on the dryer exhaust stack. By regulating the butterfly valve on the dryer exhaust stack, and applying the prescribed operations for drying wet pelletized oil furnace carbon blacks, the excess oxygen in the tail gases was adjusted in the range of φ = 3.0 % and 5.0 %, depending on the type of oil-furnace carbon blacks. Suggested also is installation of a direct-reverse automatic butterfly valve on the dryer exhaust stack to automatically determine the volume fraction of oxygen in the tail gas, and the volume flow rate of natural gas for combustion. The results the improvements carried out are shown in Tables 3 to 5. Table 2 shows the thermal calculations for the hood of the rotary dryer. Preheating of the process water in the temperature range of 70 °C and 80 °C is also recommended using the net heat from the oil-furnace process for wet pelletization. The results of preheating the process water are shown in Table 1. Depending on the type of oil-furnace carbon black, the aforementioned improvements resulted in natural gas energy savings ranging from 25 % to 35 % in relation to the average natural gas requirement in the drying process, and thus a reduction in carbon emissions of up to 40

  5. Soil susceptibility to compaction under use conditions in southern Brazil

    Directory of Open Access Journals (Sweden)

    Michael Mazurana

    Full Text Available ABSTRACT The degree of soil compaction is intensified by its inadequate management, compaction being variable depending on soil type since even under identical management conditions, different types have different abilities to withstand load. The objective of this study was to evaluate the susceptibility to compaction of different classes of soils under no-tillage (NT croping system compared to the original condition. Thus, i soils with the same source material have distinct resistance to compression with increased NT adoption time; ii the most sensitive indicators of this change are the ratios mass:volume and volume:volume and; iii there is a relationship between resistance and compaction susceptibility with the amount and type of oxide. Soil samples were collected in areas under NT and under natural condition in order to assess the impact imposed by the NT on the attributes density and porosity, precompression stress and compressibility index and relate them to the oxide type of, and content in, the soils under study. The results show that the density and macroporosity were those most affected by the NT agricultural use, regardless of soil type, that is, its dynamic is related more to soil use and less to mineralogical characteristics. The soil resistance and compaction susceptibility were higher in soil developed in basalt, followed by those developed in sandstone and granite. Both the organic matter content and type and concentration of iron oxides were related to the soil resistance and susceptibility to compaction.

  6. ALTERNATE REDUCTANT COLD CAP EVALUATION FURNACE PHASE I TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F.; Miller, D.; Zamecnik, J.; Lambert, D.

    2014-04-22

    Savannah River Remediation (SRR) conducted a Systems Engineering Evaluation (SEE) to determine the optimum alternate reductant flowsheet for the Defense Waste Processing Facility (DWPF). Specifically, two proposed flowsheets (nitric–formic–glycolic and nitric–formic–sugar) were evaluated based upon results from preliminary testing. Comparison of the two flowsheets among evaluation criteria indicated a preference towards the nitric–formic–glycolic flowsheet. Further evaluation of this flowsheet eliminated the formic acid1, and as a result, the nitric–glycolic flowsheet was recommended for further testing. Based on the development of a roadmap for the nitric–glycolic acid flowsheet, Waste Solidification Engineering (WS-E) issued a Technical Task Request (TTR) to address flammability issues that may impact the implementation of this flowsheet. Melter testing was requested in order to define the DWPF flammability envelope for the nitric glycolic acid flowsheet. The Savannah River National Laboratory (SRNL) Cold Cap Evaluation Furnace (CEF), a 1/12th scale DWPF melter, was selected by the SRR Alternate Reductant project team as the melter platform for this testing. The overall scope was divided into the following sub-tasks as discussed in the Task Technical and Quality Assurance Plan (TTQAP): Phase I - A nitric–formic acid flowsheet melter test (unbubbled) to baseline the Cold Cap Evaluation Furnace (CEF) cold cap and vapor space data to the benchmark melter flammability models Phase II - A nitric–glycolic acid flowsheet melter test (unbubbled and bubbled) to: o Define new cold cap reactions and global kinetic parameters for the melter flammability models o Quantify off-gas surging potential of the feed o Characterize off-gas condensate for complete organic and inorganic carbon species Prior to startup, a number of improvements and modifications were made to the CEF, including addition of cameras, vessel support temperature measurement, and a heating

  7. Evaluation of Retrofit Variable-Speed Furnace Fan Motors

    Energy Technology Data Exchange (ETDEWEB)

    Aldrich, R. [Steven Winter Associates, Inc., Norwalk, CT (United States); Williamson, J. [Steven Winter Associates, Inc., Norwalk, CT (United States)

    2014-01-01

    In conjunction with the New York State Energy Research and Development Authority (NYSERDA) and Proctor Engineering Group, Ltd. (PEG), the Consortium for Advanced Residential Buildings (CARB) has evaluated the Concept 3 (tm) replacement motors for residential furnaces. These brushless, permanent magnet (BPM) motors can use much less electricity than their PSC (permanent split capacitor) predecessors. This evaluation focuses on existing homes in the heating-dominated climate of upstate New York with the goals of characterizing field performance and cost-effectiveness. The results of this study are intended to be useful to home performance contractors, HVAC contractors, and home efficiency program stakeholders. The project includes eight homes in and near Syracuse, NY. Tests and monitoring was performed both before and after fan motors were replaced. Average fan power reductions were approximately 126 Watts during heating and 220 Watts during cooling operation. Over the course of entire heating and cooling seasons, these translated into average electric energy savings of 163 kWh. Average cost savings were $20 per year. Homes where the fan was used outside of heating and cooling mode saved an additional $42 per year on average. Results indicate that BPM replacement motors will be most cost-effective in HVAC systems with longer run times and relatively low duct static pressures. More dramatic savings are possible if occupants use the fan-only setting when there is no thermal load. There are millions of cold-climate, U.S. homes that meet these criteria, but the savings in most homes tested in this study were modest.

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

    Science.gov (United States)

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

    2004-06-18

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

  9. Dynamical Transition of 4He Crystallization in a Very High Porosity Aerogel

    Science.gov (United States)

    Masumoto, Ryota; Ueno, Ken-Ichi; Matsuda, Hirofumi; Nomura, Ryuji; Okuda, Yuichi

    2011-03-01

    Crystallization of 4He in aerogels of 90 and 96% porosities shows a dynamical phase transition at around 600 mK due to the competition between thermal fluctuation and disorder: crystals grow via creep at high temperatures and via avalanche at low temperatures. In a very high porosity 99.5% aerogel, however, the transition had not been observed in our previous publication (Nomura et al. in Phys. Rev. Lett. 101:175703, 2008). We improved the spatial resolution of the video image and found that the 99.5% aerogel did have the transition at around 200 mK, which is much lower than those of the lower porosities. The avalanche size is significantly smaller in the 99.5% aerogel. The reduction in the transition temperature and avalanche size may be the consequence of weaker disorder for the crystallization in the very high porosity aerogel.

  10. Characterization of porosity via secondary reactions. Final technical report, 1 September 1991--30 November 1995

    Energy Technology Data Exchange (ETDEWEB)

    Calo, J.M.; Zhang, L.; Hall, P.J.; Antxustegi, M. [Brown Univ., Providence, RI (United States). Div. of Engineering

    1997-09-01

    A new approach to the study of porosity and porosity development in coal chars during gasification was investigated. This approach involves the establishment of the relationships between the amount and type of surface complexes evolved during post-activation temperature programmed desorption (TPD), and the porosity, as measured by gas adsorption and small angle neutron scattering (SANS) techniques. With this new method, the total surface area and micropore volume can be determined by the interpretation of post-activation TPD spectra. The primary conclusion of this work is that it is possible to predict total surface area and micropore volume from TPD spectra. From the extended random pore model, additional information about the micropore surface area, the nonmicroporous surface area, and the mean micropore size development as a function of reaction time (or burn-off) can also be predicted. Therefore, combining the TPD technique and the extended random pore model provides a new method for the characterization of char porosity.

  11. Image Analysis and Estimation of Porosity and Permeability of Arnager Greensand, Upper Cretaceous, Denmark

    DEFF Research Database (Denmark)

    Solymar, Mikael; Fabricius, Ida

    1999-01-01

    Arnager Greensand consists of unconsolidated, poorly sorted fine-grained, glauconitic quartz sand, often silty or clayey, with a few horizons of cemented coarse-grained sand. Samples from the upper part of the Arnager Greensand were used for this study to estimate permeability from microscopic...... images. Backscattered Scanning Electron Microscope images from polished thin-sections were acquired for image analysis with the software PIPPIN(R). Differences in grey levels owing to density differences allowed us to estimate porosity, clay and particle content. The images were simplified into two...... magnification of the image can not resolve the microporosity within the clay fraction, so we suggest that the imaged porosity at 150x magnification is close to the effective porosity for permeability assessment. The Heporosity, however, represents the total porosity of the Arnager Greensand. For permeability...

  12. Modeling flow in porous media with double porosity/permeability: Mathematical model, properties, and analytical solutions

    CERN Document Server

    Nakshatrala, K B; Ballarini, R

    2016-01-01

    Geo-materials such as vuggy carbonates are known to exhibit multiple spatial scales. A common manifestation of spatial scales is the presence of (at least) two different scales of pores, which is commonly referred to as double porosity. To complicate things, the pore-network at each scale exhibits different permeability, and these networks are connected through fissure and conduits. Although some models are available in the literature, they lack a strong theoretical basis. This paper aims to fill this lacuna by providing the much needed theoretical foundations of the flow in porous media which exhibit double porosity/permeability. We first obtain a mathematical model for double porosity/permeability using the maximization of rate of dissipation hypothesis, and thereby providing a firm thermodynamic underpinning. We then present, along with mathematical proofs, several important mathematical properties that the solutions to the double porosity/permeability model satisfy. These properties are important in their...

  13. The formation and evolution of layered structures in porous media: effects of porosity and mechanical dispersion

    NARCIS (Netherlands)

    Schoofs, Stan; Trompert, Ron A.; Hansen, Ulrich

    1999-01-01

    Horizontally layered structures can develop in porous or partially molten environments, such as hydrothermal systems, magmatic intrusions and the early Earth's mantle. The porosity f of these natural environments is typically small. Since dissolved chemical elements unlike heat cannot diffuse

  14. A CFD-Model for prediction of unintended porosities in metal matrix composites

    DEFF Research Database (Denmark)

    Li, Shizhao; Spangenberg, Jon; Hattel, Jesper Henri

    2013-01-01

    This paper presents a numerical method that simulates the flow through the porous corridors of the preform, which in theory enables the prediction of unintended porosities at the end of the process....

  15. Investigation on Porosity and Microhardness of 316L Stainless Steel Fabricated by Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Shahir Mohd Yusuf

    2017-02-01

    Full Text Available This study investigates the porosity and microhardness of 316L stainless steel samples fabricated by selective laser melting (SLM. The porosity content was measured using the Archimedes method and the advanced X-ray computed tomography (XCT scan. High densification level (≥99% with a low average porosity content (~0.82% were obtained from the Archimedes method. The highest porosity content in the XCT-scanned sample was ~0.61. However, the pores in the SLM samples for both cases (optical microscopy and XCT were not uniformly distributed. The higher average microhardness values in the SLM samples compared to the wrought manufactured counterpart are attributed to the fine microstructures from the localised melting and rapid solidification rate of the SLM process.

  16. The effects of porosity in friction performance of brake pad using waste tire dust

    Directory of Open Access Journals (Sweden)

    İbrahim Mutlu

    2015-10-01

    Full Text Available Abstract This research is focused on the effect of porosity on the friction-wear properties of automotive brake pads. Waste Tire Dust (WTD was used as a new friction material in brake pads. Newly formulated brake pad materials with five different components have been produced by conventional techniques. In the experimental studies, the change of the friction coefficient, the temperature of the friction surface, the specific wear rate, and the hardness, density and porosity were measured. In addition, the micro-structural characterizations of brake pads are determined using Scanning Electron Microscopy (SEM. The mean coefficient of friction, porosity and specific wear are increased due to a WTD rate increases, on the other hand, hardness and density are decreased. As a result, WTD can be considered as an alternative to revalorize this kind of waste products in the brake pads and the amount of porosity of the brake pad affected the friction coefficient and wear behavior of the pad.

  17. Total and methyl mercury, moisture, and porosity in Lake Michigan surficial sediment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Total and methyl mercury, moisture content (%), and porosity were measured in Lake Michigan sediment by the U.S. Environmental Protection Agency/Office of Research...

  18. Optical method for in situ monitoring of electrospinning process and porosity characterization of microporous membrane

    Science.gov (United States)

    Chen, Chung-Han; Huang, Chieh-Tse; Fuh, Yiin-Kuen

    2017-04-01

    We present an optical-based, rapid method for the in situ porosity measurement of membranes through the electrospinning process. The method was developed by combining an optical method with in situ monitoring of the porosity of the electrospun membranes based on the measured reflected power density. The results showed that the area of bright and dark ratio is consistently proportional to the porosity of the electrospun membranes, which can potentially be used for actual characterization of the membranes. In addition, the effect of different incident angles of a laser beam was performed and compared. The porosity ratio of the electrospun membranes can be empirically evaluated as the determination coefficient R2=0.9945 to 0.9876 can be obtained. The proposed method is successfully demonstrated and validated by the SEM images of the binary method. The potential applications include the in situ monitoring of the electrospinning process for the bioassembly and biomimicking of a human tissue with a great accuracy.

  19. Monte Carlo Study on Gas Pressure Response of He-3 Tube in Neutron Porosity Logging

    Directory of Open Access Journals (Sweden)

    TIAN Li-li;ZHANG Feng;WANG Xin-guang;LIU Jun-tao

    2016-10-01

    Full Text Available Thermal neutrons are detected by (n,p reaction of Helium-3 tube in the compensated neutron logging. The helium gas pressure in the counting area influences neutron detection efficiency greatly, and then it is an important parameter for neutron porosity measurement accuracy. The variation law of counting rates of a near detector and a far one with helium gas pressure under different formation condition was simulated by Monte Carlo method. The results showed that with the increasing of helium pressure the counting rate of these detectors increased firstly and then leveled off. In addition, the neutron counting rate ratio and porosity sensitivity increased slightly, the porosity measurement error decreased exponentially, which improved the measurement accuracy. These research results can provide technical support for selecting the type of Helium-3 detector in developing neutron porosity logging.

  20. Fabrication of (U,Am)O2 pellet with controlled porosity from oxide microspheres

    Science.gov (United States)

    Ramond, Laure; Coste, Philippe; Picart, Sébastien; Gauthé, Aurélie; Bataillea, Marc

    2017-08-01

    U1-xAmxO2±δ mixed-oxides are considered as promising compounds for americium heterogeneous transmutation in Sodium Fast Neutron Reactor. Porous microstructure is envisaged in order to facilitate helium and fission gas release and to reduce pellet swelling during irradiation and under self-irradiation. In this study, the porosity is created by reducing (U,Am)3O8 microspheres into (U,Am)O2 during the sintering. This reduction is accompanied by a decrease of the lattice volume that leads to the creation of open porosity. Finally, an (U0.90Am0.10)O2 porous ceramic pellet (D∼89% of the theoretical density TD) with controlled porosity (≥8% open porosity) was obtained from mixed-oxide microspheres obtained by the Weak Acid Resin (WAR) process.

  1. Visualization and prediction of porosity in roller compacted ribbonswith near infrared chemical imaging (NIR-CI)

    DEFF Research Database (Denmark)

    Khorasani, Milad Rouhi; Amigo Rubio, Jose Manuel; Sonnergaard, Jørn

    2015-01-01

    reference methods that ribbons compressed at a higher pressure resulted in a lower mean porosity. Using NIR-CI in combination with multivariate data analysis it was possible to visualize and predict the porosity distribution of the ribbons. This approach is considered important for process monitoring......The porosity of roller compacted ribbon is recognized as an important critical quality attribute which has a huge impact on the final product quality. The purpose of this study was to investigate the use of near-infrared chemical imaging (NIR-CI) for porosity estimation of ribbons produced...... at different roll pressures. Two off-line methods were utilized as reference methods. The relatively fast method (oil absorption) was comparable with the more time-consuming mercury intrusion method (R2 = 0.98). Therefore, the oil method was selected as the reference off line method. It was confirmed by both...

  2. Self-Assembling Sup-porosity: The Effect On Fluid Flow And Seismic Wave Propagation

    Energy Technology Data Exchange (ETDEWEB)

    Pyrak-Nolte, Laura J. [Purdue University

    2013-04-27

    Fractures and joints in the field often contain debris within the void spaces. Debris originates from many different mechanisms: organic and/or inorganic chemical reactions/mineralization, sediment transport, formation of a fracture, mechanical weathering or combinations of these processes. In many cases, the presence of debris forms a sub-porosity within the fracture void space. This sub-porosity often is composed of material that differs from the fracture walls in mineralogy and morphology. The sub-porosity may partially fill voids that are on the order of hundreds of microns and thereby reduce the local porosity to lengths scales on the order of sub-microns to tens of microns. It is quite clear that a sub-porosity affects fracture porosity, permeability and storativity. What is not known is how the existence/formation of a sub-porosity affects seismic wave propagation and consequently our ability to probe changes in the subsurface caused by the formation or alteration of a sub-porosity. If seismic techniques are to be developed to monitor the injection and containment of phases in sequestration reservoirs or the propping of hydraulically induced fracture to enhance oil & gas production, it is important to understand how a sub-porosity within a fracture affects macroscopic seismic and hydraulic measurements. A sub-porosity will directly affect the interrelationship between the seismic and hydraulic properties of a fracture. This reports contains the results of the three main topics of research that were performed (1) to determine the effect of a sub-porosity composed of spherical grains on seismic wave propagation across fractures, (2) to determine the effect of biofilm growth in pores and between grains on seismic wave propagation in sediment, and (3) to determine the effect of the scale of observation (field-of-view) on monitoring alteration the pore space within a fracture caused by reactive flow. A brief summary of the results for each topic is contained in

  3. Genetic Susceptibility to Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Sanja Kovacic

    2012-01-01

    Full Text Available Atherosclerosis is a complex multifocal arterial disease involving interactions of multiple genetic and environmental factors. Advances in techniques of molecular genetics have revealed that genetic ground significantly influences susceptibility to atherosclerotic vascular diseases. Besides further investigations of monogenetic diseases, candidate genes, genetic polymorphisms, and susceptibility loci associated with atherosclerotic diseases have been identified in recent years, and their number is rapidly increasing. This paper discusses main genetic investigations fields associated with human atherosclerotic vascular diseases. The paper concludes with a discussion of the directions and implications of future genetic research in arteriosclerosis with an emphasis on prospective prediction from an early age of individuals who are predisposed to develop premature atherosclerosis as well as to facilitate the discovery of novel drug targets.

  4. Deposit growth and property development in coal-fired furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, L. [Sandia National Lab., Livermore, CA (United States)

    1995-11-01

    The objectives of this research project are: (1) to provide a self-consistent database of simultaneously measured, time-resolved ash deposit properties in well-controlled and well-defined environments and (2) to provide analytical expressions that relate deposit composition and structure to deposit properties of immediate relevance to PETC`s Combustion 2000 program. This project is distinguished from related work being done elsewhere by: (1) the development and deployment of in-situ diagnostics to monitor deposit properties, including heat transfer coefficients, porosity, emissivity, tenacity, strength, density, and viscosity; (2) the time resolution of such properties during deposit growth; (3) simultaneous measurement of structural and composition properties; (4) development of algorithms from a self-consistent, simultaneously measured database that includes the interdependence of properties; and (5) application of the results to technologically relevant environments such as those being planned under Combustion 2000 program. Work completed during FY94 emphasized diagnostic development. During FY95, this development work will be completed and we will emphasize application of the diagnostics to meet the other project objectives. Included in this work are the development and application of two in-situ, real-time diagnostic systems for monitoring the properties of inorganic materials on Heat transfer surfaces and in the gas-phase during controlled combustion of selected coal samples in Sandia`s Multifuel Combustor (MFC). Also, several diagnostics are being incorporated into the MFC that will eventually be used to characterize ash deposit properties.

  5. Modeling porosity reductions caused by mineral fouling in continuous-wall permeable reactive barriers.

    Science.gov (United States)

    Li, Lin; Benson, Craig H; Lawson, Elizabeth M

    2006-02-01

    A study was conducted to assess key factors to include when modeling porosity reductions caused by mineral fouling in permeable reactive barriers (PRBs) containing granular zero valent iron. The public domain codes MODFLOW and RT3D were used and a geochemical algorithm was developed for RT3D to simulate geochemical reactions occurring in PRBs. Results of simulations conducted with the model show that the largest porosity reductions occur between the entrance and mid-plane of the PRB as a result of precipitation of carbonate minerals and that smaller porosity reductions occur between the mid-plane and exit face due to precipitation of ferrous hydroxide. These findings are consistent with field and laboratory observations, as well as modeling predictions made by others. Parametric studies were conducted to identify the most important variables to include in a model evaluating porosity reduction. These studies showed that three minerals (CaCO3, FeCO3, and Fe(OH)2 (am)) account for more than 99% of the porosity reductions that were predicted. The porosity reduction is sensitive to influent concentrations of HCO3-, Ca2+, CO3(2-), and dissolved oxygen, the anaerobic iron corrosion rate, and the rates of CaCO3 and FeCO3 formation. The predictions also show that porosity reductions in PRBs can be spatially variable and mineral forming ions penetrate deeper into the PRB as a result of flow heterogeneities, which reflects the balance between the rate of mass transport and geochemical reaction rates. Level of aquifer heterogeneity and the contrast in hydraulic conductivity between the aquifer and PRB are the most important hydraulic variables affecting porosity reduction. Spatial continuity of aquifer hydraulic conductivity is less significant.

  6. Micro-CT analysis of filling ability and porosity of root-end filling materials

    Directory of Open Access Journals (Sweden)

    Mário TANOMARU-FILHO

    2017-12-01

    Full Text Available Abstract Introduction Filling ability of retrograde cavity and porosity are important properties for root-end filling materials and may be evaluated by using microcomputed tomography (micro-CT. Objective To evaluate filling ability and porosity of root-end filling materials using microcomputed tomography (micro-CT. Material and method Cavities with 1 mm internal diameter and 3 mm depth were prepared in bovine dentin sections by using ultrasonic tips (CVD No. 6.1107-6, and filled by Mineral Trioxide Aggregate (MTA; Sealer 26 (S26 and zinc oxide and eugenol cement (ZOE. Before and after filling, cavities were scanned by using micro-CT (SkyScan 1176. Filling and porosity were analyzed by using CTAn software. Filling ability was calculated based on volumetric percentage of the filled cavity. The number and percentage of closed pores were measured throughout entire extension of the filled cavity (total and in each third (cervical, middle and apical, by using bi and tridimensional analyses. The filling data were submitted to ANOVA and Tukey statistical tests, and porosity data to Kruskall-Wallis and Dunn tests, at a 5% significance level. Result S26 and ZOE presented higher filling ability than MTA (p<0.05. S26 showed the highest total porosity (number and percentage (p<0.05. In all thirds after 2D and 3D analyses, porosity was higher for S26 in comparison to MTA and ZOE (p<0.05. Conclusion Although Sealer 26 presented more porosity, the material was associated with a great filling ability. Micro-CT analysis showed no correlation between filling ability and porosity.

  7. Estimation of Fracture Porosity in an Unsaturated Fractured Welded Tuff Using Gas Tracer Testing

    Energy Technology Data Exchange (ETDEWEB)

    B.M. Freifeild

    2001-10-18

    Kinematic fracture porosity is an important hydrologic transport parameter for predicting the potential of rapid contaminant migration through fractured rock. The transport velocity of a solute moving within a fracture network is inversely related to the fracture porosity. Since fracture porosity is often one or two orders of magnitude smaller than matrix porosity, and fracture permeability is often orders of magnitude greater than matrix permeability, solutes may travel significantly faster in the fracture network than in the surrounding matrix. This dissertation introduces a new methodology for conducting gas tracer tests using a field portable mass spectrometer along with analytical tools for estimating fracture porosity using the measured tracer concentration breakthrough curves. Field experiments were conducted at Yucca Mountain, Nevada, consisting of air-permeability transient testing and gas-tracer-transport tests. The experiments were conducted from boreholes drilled within an underground tunnel as part of an investigation of rock mass hydrological behavior. Air-permeability pressure transients, recorded during constant mass flux injections, have been analyzed using a numerical inversion procedure to identify fracture permeability and porosity. Dipole gas tracer tests have also been conducted from the same boreholes used for air-permeability testing. Mass breakthrough data has been analyzed using a random walk particle-tracking model, with a dispersivity that is a function of the advective velocity. The estimated fracture porosity using the tracer test and air-injection test data ranges from .001 to .015. These values are an order of magnitude greater than the values estimated by others using hydraulically estimated fracture apertures. The estimates of porosity made using air-permeability test data are shown to be highly sensitive to formation heterogeneity. Uncertainty analyses performed on the gas tracer test results show high confidence in the parameter

  8. Estimation of fracture porosity in an unsaturated fractured welded tuff using gas tracer testing

    Energy Technology Data Exchange (ETDEWEB)

    Freifeld, Barry Mark [Univ. of California, Berkeley, CA (United States)

    2001-12-01

    Kinematic fracture porosity is an important hydrologic transport parameter for predicting the potential of rapid contaminant migration through fractured rock. The transport velocity of a solute moving within a fracture network is inversely related to the fracture porosity. Since fracture porosity is often one or two orders of magnitude smaller than matrix porosity, and fracture permeability is often orders of magnitude greater than matrix permeability, solutes may travel significantly faster in the fracture network than in the surrounding matrix. This dissertation introduces a new methodology for conducting gas tracer tests using a field portable mass spectrometer along with analytical tools for estimating fracture porosity using the measured tracer concentration breakthrough curves. Field experiments were conducted at Yucca Mountain, Nevada, consisting of air-permeability transient testing and gas-tracer-transport tests. The experiments were conducted from boreholes drilled within an underground tunnel as part of an investigation of rock mass hydrological behavior. Air-permeability pressure transients, recorded during constant mass flux injections, have been analyzed using a numerical inversion procedure to identify fracture permeability and porosity. Dipole gas tracer tests have also been conducted from the same boreholes used for air-permeability testing. Mass breakthrough data has been analyzed using a random walk particle-tracking model, with a dispersivity that is a function of the advective velocity. The estimated fracture porosity using the tracer test and air-injection test data ranges from .001 to .015. These values are an order of magnitude greater than the values estimated by others using hydraulically estimated fracture apertures. The estimates of porosity made using air-permeability test data are shown to be highly sensitive to formation heterogeneity. Uncertainty analyses performed on the gas tracer test results show high confidence in the parameter

  9. METHODS AND DEVICES FOR CONTROL OF OPEN MICROSCOPIC POROSITY OF PORCELAIN INSULATORS

    OpenAIRE

    Galagan, Roman

    2014-01-01

    Examined the methods and devices of control of porcelain insulators for presence of defects such as open microscopic porosity. It is shown that open microscopic porosity is the most dangerous defect production origin and is responsible for over 80% of failures of porcelain support insulators. Considered methods of control are divided into two groups: destructive and non-destructive. For each method are highlighted their advantages and disadvantages. The analysis showed that most of the existi...

  10. Combustion of Solid Fuel in a Vortex Furnace with Counter-swirling Flows

    Directory of Open Access Journals (Sweden)

    Redko A.A.

    2017-12-01

    Full Text Available The results of computer simulation of the processes of incineration of low-grade solid fuel-pulverized peat with a moisture content of 40%, an ash content of 6% are given. It has been determined the fields of distribution of temperature, velocity of gases and particles in the volume and at the outlet from the furnace. The three-dimensional temperature distribution in the combustion chamber indicates high-temperature combustion of peat particles at temperatures above 1700°C with liquid ash removal in the lower part of the furnace. It has been determined that when the furnace is cooled, it is not ensured combustion of the fuel completely. The value of the swirling flow rate at the outlet from the furnace (up to 370 m/s ensures the efficiency of separation of fuel particles, reducing heat losses from mechanical underburning. It is determined that the concentration of oxygen is close to zero over the entire height of the furnace, at an outlet from the furnace the oxygen concentration is 5...6%, since oxygen is supplied with excess (αв=1,2. The results of a numerical study showed that the diameter of peat particles affects the process of their combustion: coke particles with an initial diameter of 25 mkm to 250 mkm burn out by 96%. With an increase in particle diameter up to 1000 mkm, the degree of burn-out of coke decreases, but at the same time their removal decreases. It is shown that the furnace ensures the completeness of combustion of peat particles of peat 99.8%, volatiles is 100%.

  11. Modeling of Thermochemical Behavior in an Industrial-Scale Rotary Hearth Furnace for Metallurgical Dust Recycling

    Science.gov (United States)

    Wu, Yu-Liang; Jiang, Ze-Yi; Zhang, Xin-Xin; Xue, Qing-Guo; Yu, Ai-Bing; Shen, Yan-Song

    2017-10-01

    Metallurgical dusts can be recycled through direct reduction in rotary hearth furnaces (RHFs) via addition into carbon-based composite pellets. While iron in the dust is recycled, several heavy and alkali metal elements harmful for blast furnace operation, including Zn, Pb, K, and Na, can also be separated and then recycled. However, there is a lack of understanding on thermochemical behavior related to direct reduction in an industrial-scale RHF, especially removal behavior of Zn, Pb, K, and Na, leading to technical issues in industrial practice. In this work, an integrated model of the direct reduction process in an industrial-scale RHF is described. The integrated model includes three mathematical submodels and one physical model, specifically, a three-dimensional (3-D) CFD model of gas flow and heat transfer in an RHF chamber, a one-dimensional (1-D) CFD model of direct reduction inside a pellet, an energy/mass equilibrium model, and a reduction physical experiment using a Si-Mo furnace. The model is validated by comparing the simulation results with measurements in terms of furnace temperature, furnace pressure, and pellet indexes. The model is then used for describing in-furnace phenomena and pellet behavior in terms of heat transfer, direct reduction, and removal of a range of heavy and alkali metal elements under industrial-scale RHF conditions. The results show that the furnace temperature in the preheating section should be kept at a higher level in an industrial-scale RHF compared with that in a pilot-scale RHF. The removal rates of heavy and alkali metal elements inside the composite pellet are all faster than iron metallization, specifically in the order of Pb, Zn, K, and Na.

  12. Reduction of carbon monoxide emission from a solid-fuel thermo-accumulation furnace

    Directory of Open Access Journals (Sweden)

    Dakić Dragoljub

    2006-01-01

    Full Text Available Many households in Serbia, using electric thermo-accumulation furnaces for heating, have been forced to find an alternative solution, due to a significant increase in electricity prices during the last decade. A possible solution is replacing electric heating appliances with the solid fuel-fired ones. A prototype of a new concept of thermo-accumulation solid fuel-fired furnace has been developed to meet these growing needs, providing electricity saving together with considerable environmental benefits. Two strategies for reduction of carbon monoxide emission are examined in the paper: application of Pt/Al2O3 catalyst, in the form of 3 ± 0.3 mm spheres, providing further combustion of flue gases within the furnace, as well as an additional emission reduction by means of the air excess control. Experimental investigations of the catalyst influence on the conversion of carbon monoxide have been done for different operation regimes and positions of the catalyst. The paper presents selected results regarding carbon monoxide emission during wood and coal combustion. Investigations suggest a considerable effect of the catalyst and a strong influence of the catalyst position within the furnace to carbon monoxide emission reduction. In addition, experimental tests have been conducted to asses the effect of the air excess control in the furnace on carbon monoxide emission. The amount of combustion air, the flue gas flow rate, and the fuel feeding regime have been adjusted in order to keep the flue gas oxygen content in a relatively narrow range, thus obtaining controlled combustion conditions and lower carbon monoxide emission. In this way, the furnace has been made able to respond to the changes in heating needs, fuel quality and other parameters, which is advantageous in comparison with similar solid-fuel fired furnaces. .

  13. Marijuana Usage and Hypnotic Susceptibility

    Science.gov (United States)

    Franzini, Louis R.; McDonald, Roy D.

    1973-01-01

    Anonymous self-reported drug usage data and hypnotic susceptibility scores were obtained from 282 college students. Frequent marijuana users (more than 10 times) showed greater susceptibility to hypnosis than nonusers. (Author)

  14. Effects of compositions of filler, binder and porosity on elastic and fracture properties of nuclear graphite

    Energy Technology Data Exchange (ETDEWEB)

    Kyaw, S.T., E-mail: si.kyaw@nottingham.ac.uk; Sun, W.; Becker, A.A.

    2015-02-15

    Highlights: • Micromechanics based homogenisation method is used for graphite microstructures. • Elastic and fracture properties are estimated based on graphite microstructures. • Fracture behaviours are studied using compact tension simulation. • Fracture behaviours are studied using four point bending simulation. • Flexural strengths were obtained and compared to experimental results from literature. - Abstract: Physical mechanisms at different length scales have to be taken into account while predicting the overall failure of nuclear graphite structures of advanced gas cooled graphite reactors. In this paper, the effect of composition of meso graphite phases and porosity on the aggregate elastic properties is predicted using the Eshelby homogenisation method. Results indicate an overall decrease in elastic modulus with an increase in porosity. Subsequently, the moduli at different porosity levels are used to predict the critical strain energy release rates for crack propagation of graphite, and fracture behaviour is studied using compact tension and four point bending tests. Compared to flexural strength at zero porosity level, significant reduction in strength of up to 80% at 30% porosity level is observed. Evolution of flexural strength due to porosity is also compared against available experimental values of graphite from UK nuclear plants.

  15. Effect of increased strut porosity of calcium phosphate bone graft substitute biomaterials on osteoinduction.

    Science.gov (United States)

    Coathup, Melanie J; Hing, Karin A; Samizadeh, Sorousheh; Chan, Oliver; Fang, Yvette S; Campion, Charlie; Buckland, Thomas; Blunn, Gordon W

    2012-06-01

    The effect of increasing strut porosity on the osteoinductivity of porous calcium phosphate (CaP) and silicate-substituted calcium phosphate (SiCaP) bone substitute materials was investigated in an ovine ectopic model. One to two millimeter-sized granules or block implants with strut porosities of 10, 20, or 30% were inserted into the left and right paraspinalis muscle. At 12 weeks, histological sections were prepared through the center of each implant and bone contact, bone area and implant area quantified. Backscattered scanning electron microscopy (bSEM) was used to visualize bone within small pores in the struts of the scaffolds. Increased bone formation was measured in the SiCaP with 30% strut porosity (5.482% ± 1.546%) when compared with the nonsilicate CaP with the same morphology (1.160% ± 0.502%, p = 0.02), indicating that silicate substitution may increase osteoinduction. Greater bone formation was seen in scaffolds with increased strut porosity. No bone growth was found in any of the SiCaP scaffold with 10% porosity. There was no significant difference between block and granule specimens. Scanning electron microscopy and EDX in combination with histology demonstrated bone formation within pores <5 μm in size. The use of silicate-substituted CaP material with increased strut porosity may further augment repair and regeneration in bony sites. Copyright © 2012 Wiley Periodicals, Inc.

  16. Porosity measurement of solid pharmaceutical dosage forms by gamma-ray transmission

    Energy Technology Data Exchange (ETDEWEB)

    Martins de Oliveira, Jose, E-mail: jose.oliveira@prof.uniso.b [Universidade de Sorocaba, UNISO, Campus Seminario, Caixa Postal 578, Avenue, Dr. Eugenio Salermo, 100, Centro, 18035-430 Sorocaba, SP (Brazil); Andreo Filho, Newton; Vinicius Chaud, Marco; Angiolucci, Tatiana; Aranha, Norberto [Universidade de Sorocaba, UNISO, Campus Seminario, Caixa Postal 578, Avenue, Dr. Eugenio Salermo, 100, Centro, 18035-430 Sorocaba, SP (Brazil); Germano Martins, Antonio Cesar [Universidade Estadual Paulista Julio de Mesquita Filho, UNESP, GAGI, Avenue, 3 de Marco, 511, Alto da Boa Vista, 18087-180 Sorocaba, SP (Brazil)

    2010-12-15

    The aim of the present work is the determination of porosity in tablets by using the gamma-ray transmission technique. Tablet dissolution depends on some inherent characteristics of the manufacturing process, such as compression force, tablet volume, density and porosity, nature of excipients, preparation methods and its physical-chemical properties. Porosity is a measure of empty spaces in a material and can be determined by various techniques. In this paper, we propose the use of a gamma-ray transmission technique to obtain the porosity of experimental formulation of tablets. The results of porosity were compared with those obtained by using conventional methodology (density and mercury intrusion). The experimental setup for gamma-ray transmission consists of a gamma-ray source of {sup 241}Am (photons of 59.6 keV and an activity of 3.7x10{sup 9} Bq), an NaI(Tl) scintillation detector, collimators and a standard gamma-ray spectrometry electronics. Our results suggest that the gamma-ray transmission technique is a powerful tool for non-destructive porosity quantification of solid pharmaceutical forms and presents smaller errors than those obtained with conventional methodologies.

  17. Influence of shrinkage porosity on fatigue performance of iron castings and life estimation method

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2016-01-01

    Full Text Available Shrinkage porosity exists more or less in heavy castings, and it plays an important role in the fatigue behavior of cast materials. In this study, fatigue tests were carried out on the QT400-18 cast iron specimens containing random degrees of shrinkage porosity defect. Experimental results showed that the order of magnitude of life scattered from 103 to 106 cycles when the shrinkage percentage ranged from 0.67% to 5.91%. SEM analyses were carried out on the shrinkage porosity region. The inter-granular discontinuous, micro cracks and inclusions interfered with the fatigue sliding or hindering process. The slip in shrinkage porosity region was not as orderly as the ordinary continuous medium. The shrinkage porosity area on fracture surface (SPAFS and alternating stress intensity factor (ASIF were applied to evaluate the tendency of residual life distribution; their relationship was fitted by negative exponent functions. Based on the intermediate variable of ASIF, a fatigue life prediction model of nodular cast iron containing shrinkage porosity defects was established. The modeling prediction was in agreement with the experimental results.

  18. Study of the effects of stress sensitivity on the permeability and porosity of fractal porous media

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Xiao-Hua, E-mail: xiaohua-tan@163.com; Li, Xiao-Ping; Liu, Jian-Yi; Zhang, Lie-Hui; Fan, Zhou

    2015-10-16

    Flow in porous media under stress is very important in various scientific and engineering fields. It has been shown that stress plays an important role in effect of permeability and porosity of porous media. In this work, novel predictive models for permeability and porosity of porous media considering stress sensitivity are developed based on the fractal theory and mechanics of materials. Every parameter in the proposed models has clear physical meaning. The proposed models are evaluated using previously published data for permeability and porosity measured in various natural materials. The predictions of permeability and porosity show good agreement with those obtained by the available experimental data and illustrate that the proposed models can be used to characterize the flow in porous media under stress accurately. - Highlights: • Predictive models for permeability and porosity of porous media considering stress sensitivity are developed. • The fractal theory and mechanics of materials are used in these models. • The predictions of permeability and porosity show good agreement with those obtained by the available experimental data. • The proposed models can be used to characterize the flow in porous media under stress accurately.

  19. Porosity-dependent nonlinear forced vibration analysis of functionally graded piezoelectric smart material plates

    Science.gov (United States)

    Qing Wang, Yan; Zu, Jean W.

    2017-10-01

    This work investigates the porosity-dependent nonlinear forced vibrations of functionally graded piezoelectric material (FGPM) plates by using both analytical and numerical methods. The FGPM plates contain porosities owing to the technical issues during the preparation of FGPMs. Two types of porosity distribution, namely, even and uneven distribution, are considered. A modified power law model is adopted to describe the material properties of the porous FGPM plates. Using D’Alembert’s principle, the out-of-plane equation of motion is derived by taking into account the Kármán nonlinear geometrical relations. After that, the Galerkin method is used to discretize the equation of motion, resulting in a set of ordinary differential equations with respect to time. These ordinary differential equations are solved analytically by employing the harmonic balance method. The approximate analytical results are verified by using the adaptive step-size fourth-order Runge-Kutta method. By means of the perturbation technique, the stability of approximate analytical solutions is examined. An interesting nonlinear broadband vibration phenomenon is detected in the FGPM plates with porosities. Nonlinear frequency-response characteristics of the present smart structures are investigated for various system parameters including the porosity type, the porosity volume fraction, the electric potential, the external excitation, the damping and the constituent volume fraction. It is found that these parameters have significant effects on the nonlinear vibration characteristics of porous FGPM plates.

  20. Shallow-water models with anisotropic porosity and merging for flood modelling on Cartesian grids

    Science.gov (United States)

    Bruwier, M.; Archambeau, P.; Erpicum, S.; Pirotton, M.; Dewals, B.

    2017-11-01

    Shallow-water models with porosity are used to compute floods at a relatively coarse resolution while accounting indirectly for detailed topographic data through porosity parameters. In many practical applications, these models enable a significant reduction of the computational time while maintaining an acceptable level of accuracy. In this paper, we improve the use of porosity models on Cartesian grids by three original contributions. First, a merging technique is used to handle cells with low porosity values which tend otherwise to seriously hamper computational efficiency. Next, we show that the optimal method for the determination of the porosity parameters depends on the modelling scale, i.e. the grid resolution compared to the characteristic size of obstacles and flow ways. Finally, we investigate the potential benefit of using a different porosity parameter in each term of the shallow-water equations. Five test cases, two of them being original, are used to validate the model and assess each contribution. In particular, we obtained speedup values between 10 and 100 while the errors on water depths remain around few percent.

  1. Porosity Gradient Development Around Karst Features due to Tidal Pumping in Eastern Yucatan Peninsula

    Science.gov (United States)

    Maqueda, A.; Renard, P.

    2016-12-01

    Water exchange between karst features and the porous matrix around them has been observed in karst aquifers by previous research. The exchange is driven by hydraulic head gradients caused by stormwater runoff or sea tides and may cause mineral dissolution. The authors of this work proposed a conceptual model of porosity development under tidal variations of hydraulic head is proposed. Simulations of reactive transport and porosity evolution were conducted to explore the porosity gradient development around a karst feature. Simulations account for petrophysical properties of porous media and groundwater geochemical characteristics. Data used in simulations corresponds to an eogenetic karst aquifer found on the eastern coast of Yucatan Peninsula in Mexico. Simulations include both analytical and numerical solutions of porosity increase caused by mineral dissolution. The estimated rate of porosity development and associated wall retreat (3-30 cm/100 yr) are large enough to develop karst cavities on time periods relevant to karst formation in the study area (10K yr). The analytical solution could be used to assess porosity increase in rock samples and can be also applied to model slow reactions in porous media under flow driven by sinusoidal hydraulic boundary conditions. The results show a possible alternative mechanism of karst cavity development in a high conductive limestone rock matrix aquifer.

  2. Impact of surface porosity and topography on the mechanical behavior of high strength biomedical polymers.

    Science.gov (United States)

    Evans, Nathan T; Irvin, Cameron W; Safranski, David L; Gall, Ken

    2016-06-01

    The ability to control the surface topography of orthopedic implant materials is desired to improve osseointegration but is often at the expense of mechanical performance in load bearing environments. Here we investigate the effects of surface modifications, roughness and porosity, on the mechanical properties of a set of polymers with diverse chemistry and structure. Both roughness and surface porosity resulted in samples with lower strength, failure strain and fatigue life due to stress concentrations at the surface; however, the decrease in ductility and fatigue strength were greater than the decrease in monotonic strength. The fatigue properties of the injection molded polymers did not correlate with yield strength as would be traditionally observed in metals. Rather, the fatigue properties and the capacity to maintain properties with the introduction of surface porosity correlated with the fracture toughness of the polymers. Polymer structure impacted the materials relative capacity to maintain monotonic and cyclic properties in the face of surface texture and porosity. Generally, amorphous polymers with large ratios of upper to lower yield points demonstrated a more significant drop in ductility and fatigue strength with the introduction of porosity compared to crystalline polymers with smaller ratios in their upper to lower yield strength. The latter materials have more effective dissipation mechanisms to minimize the impact of surface porosity on both monotonic and cyclic damage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. The porosity formation mechanism in the laser-MIG hybrid welded joint of Invar alloy

    Science.gov (United States)

    Zhan, Xiaohong; Gao, Qiyu; Gu, Cheng; Sun, Weihua; Chen, Jicheng; Wei, Yanhong

    2017-10-01

    The porosity formation mechanism in the laser-metal inter gas (MIG) multi-layer hybrid welded (HW) joint of 19.05 mm thick Invar alloy is investigated. The microstructure characteristics and energy dispersive spectroscopy (EDS) are analyzed. The phase identification was conducted by the X-ray diffractometer (XRD). Experimental results show that the generation of porosity is caused by the relatively low laser power in the root pass and low current in the cover pass. It is also indicated that the microstructures of the welded joints are mainly observed to be columnar crystal and equiaxial crystal, which are closely related to the porosity formation. The EDS results show that oxygen content is significantly high in the inner wall of the porosity. The XRD results indicate that the BM and the WB of laser-MIG HW all are composed of Fe0.64Ni0.36 and γ-(Fe,Ni). When the weld pool is cooled quickly, [NiO] [FeO] and [MnO] are formed that react on C to generate CO/CO2 gases. The porosity of laser-MIG HW for Invar alloy is oxygen pore. The root source of metallurgy porosity formation is that the dissolved gases are hard to escape sufficiently and thus exist in the weld pool. Furthermore, 99.99% pure Argon is recommended as protective gas in the laser-MIG HW of Invar alloy.

  4. Porosity estimation by semi-supervised learning with sparsely available labeled samples

    Science.gov (United States)

    Lima, Luiz Alberto; Görnitz, Nico; Varella, Luiz Eduardo; Vellasco, Marley; Müller, Klaus-Robert; Nakajima, Shinichi

    2017-09-01

    This paper addresses the porosity estimation problem from seismic impedance volumes and porosity samples located in a small group of exploratory wells. Regression methods, trained on the impedance as inputs and the porosity as output labels, generally suffer from extremely expensive (and hence sparsely available) porosity samples. To optimally make use of the valuable porosity data, a semi-supervised machine learning method was proposed, Transductive Conditional Random Field Regression (TCRFR), showing good performance (Görnitz et al., 2017). TCRFR, however, still requires more labeled data than those usually available, which creates a gap when applying the method to the porosity estimation problem in realistic situations. In this paper, we aim to fill this gap by introducing two graph-based preprocessing techniques, which adapt the original TCRFR for extremely weakly supervised scenarios. Our new method outperforms the previous automatic estimation methods on synthetic data and provides a comparable result to the manual labored, time-consuming geostatistics approach on real data, proving its potential as a practical industrial tool.

  5. Flat flame burner on an aluminium melting and holding furnace. A demonstration at Alycast Ltd. (Telford (GB)). Final report

    Energy Technology Data Exchange (ETDEWEB)

    1987-03-01

    The installation of a flat flame burner furnace at a pressure diecasting foundry as part of a UK Energy Efficiency Demonstration Project is described. The new furnace has a higher thermal efficiency, requires reduced maintenance and has increased operational flexibility compared to conventional furnaces. The energy savings are such as to achieve a payback period of six months. Suggestions for future improvements are also included.

  6. Non-destructive testing (NDT) and inspection of the blast furnace refractory lining by stress wave propagation technique

    OpenAIRE

    Sadri, A; Gebski, P.; Gordon, Y.

    2014-01-01

    Generally speaking, a blast furnace is the main equipment in Ironmaking and the campaign life of a blast furnace depends on its remaining hearth refractory lining [1]. The Acousto Ultrasonic- Echo (AU-E) is a stress wave propagation technique that uses time and frequency data analysis to determine coarse-grained material thicknesses, such as refractory and stave materials in operating blast furnaces. A mechanical impact on the surface of the structure (via a hammer or a mechanical impactor) g...

  7. Studies Regarding the Elaboration of the Manganese Austenitic Steel in the Induction Electric Furnace with Acid Coating

    Directory of Open Access Journals (Sweden)

    Constantin Marta

    2010-10-01

    Full Text Available The paper forwards a method of elaborating the manganese austenitic steel in induction electric furnaces with a capacity of 250 Kg having an acid furnace coating. Considering the fact that when elaborating the manganese austenitic steel sulphur can be obtained under 0.02% constitutes an additional reason to attempt the elaboration of this steel in the electric furnaces through induction with acid coating, even if the load has over 0.02% S.

  8. Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high temperature furnace (HITAF). Quarterly progress report No. 3, July--September 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    A concept for an advanced coal-fired combined-cycle power generating system is currently being developed. The first phase of this three-phase program consists of conducting the necessary research and development to define the system, evaluate the economic and technical feasibility of the concept, and prepare an R & D plan to develop the concept further. Foster Wheeler Development Corporation is leading a team ofcompanies involved in this effort. The system proposed to meet these goals is a combined-cycle system where air for a gas turbine is indirectly heated to approximately 1800{degrees}F in furnaces fired with cool-derived fuels and then directly heated in a natural-gas-fired combustor up to about 2400{degrees}F. The system is based on a pyrolyzing process that converts the coal into a low-Btu fuel gas and char. The fuelgas is a relatively clean fuel, and it is fired to heat tube surfaces that are susceptible to corrosion and problems from ash deposition. In particular, the high-temperature air heater tubes, which will need tobe a ceramic material, will be located in a separate furnace or region of a furnace that is exposed to combustion products from the low-Btu fuel gas only. A simplified process flow diagram is shown.

  9. EFFECTS OF BLAST-FURNACE SLAG ON NATURAL POZZOLAN-BASED GEOPOLYMER CEMENT

    Directory of Open Access Journals (Sweden)

    MAHSHAD YAZDANIPOUR

    2011-03-01

    Full Text Available A number of geopolymer cement mixes were designed and produced by alkali-activation of a pumice-type natural pozzolan. Effects of blast-furnace slag on basic engineering properties of the mixes were studied. Different engineering properties of the mixes such as setting times and 28-day compressive strength were studied at different amounts of blast-furnace slag, sodium oxide content, and water-to-cement ratio. The mix comprising of 5 wt.% blast-furnace slag and 8 wt.% Na2O with a water-to-dry binder ratio of 0.30 exhibits the highest 28-day compressive strength, i.e. 36 MPa. Mixes containing 5 wt.% of ground granulated blast furnace slag showed the least efflorescence or best soundness. Laboratory techniques of X-ray diffractometry (XRD, fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM were utilized for characterizing a number of mixes and studying their molecular and micro-structure. Investigations done by scanning electron microscopy confirm that smaller blast-furnace slag particles react totally while the larger ones react partially with alkaline activators and contribute to the formation of a composite microstructure.

  10. 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.

  11. A numerical investigation of the aerodynamics of a furnace with a movable block burner

    Directory of Open Access Journals (Sweden)

    T. J. Fudihara

    2007-06-01

    Full Text Available In this work the air flow in a furnace was computationally investigated. The furnace, for which experimental test data are available, is composed of a movable block burner connected to a cylindrical combustion chamber by a conical quarl. The apertures between the movable and the fixed blocks of the burner determine the ratio of the tangential to the radial air streams supplied to the furnace. Three different positions of the movable blocks were studied at this time. A three-dimensional investigation was performed by means of the finite volume method. The numerical grid was developed by the multiblock technique. The turbulence phenomenon was addressed by the RNG k-epsilon model. Profiles of the axial, tangential and radial velocities in the combustion chamber were outlined. The map of the predicted axial velocity in the combustion chamber was compared with a map of the experimental axial velocity. The internal space of the furnace was found to be partially filled with a reverse flow that extended around the longitudinal axis. A swirl number profile along the furnace length is presented and shows an unexpected increase in the swirl in the combustion chamber.

  12. Structure modification and constant remelting speed control of a 120-t three-phase electroslag furnace

    Directory of Open Access Journals (Sweden)

    Wang Changzhou

    2012-11-01

    Full Text Available The traditional large electroslag remelting furnaces have many shortages, such as high short-network impedance and inductance, long maintenance time for electrode replacement, low stiffness of driveline, and low control accuracy of remelting speed. The present research was aimed to solve these problems through structure modification and constant remelting speed control for a 120-t electroslag remelting (ESR furnace. Based on the technique of three-phase double electrodes in series, the short-network system and the structure of the 120-t ESR furnace were improved; and a continuous feeding system for the self-consumption electrode was proposed. A self-designed fully hydraulic driveline system with three degrees of freedom was successfully applied to the 120-t ESR furnace. An electrode auto-replacement system and the S-style speed-control curve of electrode-feeding system were designed on the basis of the soft measurement/sensing model on the remaining electrode length so as to obtain a high accuracy control system for constant remelting speed. The experiment products showed good surface quality and cross-sectional results, indicating good system control, and verifying the effectiveness of the structure modification of the furnace.

  13. Model Predictive Control of the Exit Part Temperature for an Austenitization Furnace

    Directory of Open Access Journals (Sweden)

    Hari S. Ganesh

    2016-12-01

    Full Text Available Quench hardening is the process of strengthening and hardening ferrous metals and alloys by heating the material to a specific temperature to form austenite (austenitization, followed by rapid cooling (quenching in water, brine or oil to introduce a hardened phase called martensite. The material is then often tempered to increase toughness, as it may decrease from the quench hardening process. The austenitization process is highly energy-intensive and many of the industrial austenitization furnaces were built and equipped prior to the advent of advanced control strategies and thus use large, sub-optimal amounts of energy. The model computes the energy usage of the furnace and the part temperature profile as a function of time and position within the furnace under temperature feedback control. In this paper, the aforementioned model is used to simulate the furnace for a batch of forty parts under heuristic temperature set points suggested by the operators of the plant. A model predictive control (MPC system is then developed and deployed to control the the part temperature at the furnace exit thereby preventing the parts from overheating. An energy efficiency gain of 5.3 % was obtained under model predictive control compared to operation under heuristic temperature set points tracked by a regulatory control layer.

  14. High-Temperature (940 °C) furnace in 18/20 T cold bore magnet

    Science.gov (United States)

    Wang, Ze; Hou, Yubin; Feng, Qiyuan; Dong, Hongliang; Lu, Qingyou

    2018-01-01

    We present a high-temperature furnace that can work continuously in an 18/20 T cold bore magnet. A specially designed liquid nitrogen (LN2) jacket is between the high-temperature parts of the furnace and the liquid helium in the magnet Dewar. With LN2 serving as the cooling medium, the calculated value of radiation received by the liquid helium (LHe) is as low as 0.004 W. The furnace can be put into LHe Dewar directly. Together with the magnet, the furnace can provide experimental conditions of a strong static magnetic field and temperatures up to 940 °C. A cobalt oxide synthesis in solution was carried out at 200 °C with and without a 15 T magnetic field for 8 h. Differences in material structure with the applied field were observed in transmission electron micrographs of the products. A Co film sample was treated at 900 °C with and without a 6.8 T magnetic field for 30 min. The scanning electron micrographs of the treated samples show that magnetic field had a clear effect on the heat treatment process. These two applications confirmed the performance of the furnace both in high magnetic field and at high temperature.

  15. Thermal Field Analysis and Simulation of an Infrared Belt Furnace Used for Solar Cells

    Directory of Open Access Journals (Sweden)

    Bai Lu

    2014-01-01

    Full Text Available During solar cell firing, volatile organic compounds (VOC and a small number of metal particles were removed using the gas flow. When the gas flow was disturbed by the thermal field of infrared belt furnace and structure, the metal particles in the discharging gas flow randomly adhered to the surface of solar cell, possibly causing contamination. Meanwhile, the gas flow also affected the thermal uniformity of the solar cell. In this paper, the heating mechanism of the solar cell caused by radiation, convection, and conduction during firing was analyzed. Afterward, four 2-dimensional (2D models of the furnace were proposed. The transient thermal fields with different gas inlets, outlets, and internal structures were simulated. The thermal fields and the temperature of the solar cell could remain stable and uniform when the gas outlets were installed at the ends and in the middle of the furnace, with the gas inlets being distributed evenly. To verify the results, we produced four types of furnaces according to the four simulated results. The experimental results indicated that the thermal distribution of the furnace and the characteristics of the solar cells were consistent with the simulation. These experiments improved the efficiency of the solar cells while optimizing the solar cell manufacturing equipment.

  16. Composite cements containing natural pozzolan and granulated blast furnace slag

    Directory of Open Access Journals (Sweden)

    Irassar, E. F.

    2006-09-01

    Full Text Available For reasons of market demand and Portland cement production,the manufacture of cements with two or more separately ground additions to produce customized cements is becoming common practice.When pozzolan or slag content in this type of cements is high, however, the initial strength of the resulting product may be adversely impacted. This problem can be minimized by activating one or both of the replacement materials. The present study analyzes the effect of Portland cement additions such as physically activated natural pozzolan(up to 20% and/or granulated blast furnace slag (up to 35% on mortar flexural and compressive strength. The results show that higher strength is attained in ternary than binary cements. Initially (2 and 7 days, the highest compressive strengths are reached by mortars with up to 13% natural pozzolan and 5% slag, whereas at later ages mortars with larger proportions of additions are found to perform best.Debido a las exigencias del mercado y de la producción de cemento Portland, es cada vez más frecuente la elaboración de cementos con dos o más adiciones a partir de la molienda separada de sus constituyentes, dando origen a la formulación de los cementos a medida.Cuando el contenido de adiciones es alto, la utilización de puzolana y escoria en este tipo de cementos presenta la peculiaridad de disminuir la resistencia inicial del cemento resultante. Sin embargo, si algunas o ambas adiciones se activan, este problema puede minimizarse. En este trabajo se analiza la influencia de la incorporación al cemento Portland de puzolana natural (hasta 20% activada físicamente y/o escoria granulada de alto horno (hasta 35% sobre la resistencia a flexión y a compresión de morteros. Los resultados indican que los cementos ternarios presentan un mejor comportamiento resistente que los cementos binarios. Las máximas resistencias a compresión en las primeras edades (2 y 7 díasse alcanzan con hasta 13% de puzolana natural y 5% de

  17. Alternate Reductant Cold Cap Evaluation Furnace Phase II Testing

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, F. C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Stone, M. E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Miller, D. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2014-09-03

    Savannah River Remediation (SRR) conducted a Systems Engineering Evaluation (SEE) to determine the optimum alternate reductant flowsheet for the Defense Waste Processing Facility (DWPF). Specifically, two proposed flowsheets (nitric–formic–glycolic and nitric–formic–sugar) were evaluated based upon results from preliminary testing. Comparison of the two flowsheets among evaluation criteria indicated a preference towards the nitric–formic–glycolic flowsheet. Further research and development of this flowsheet eliminated the formic acid, and as a result, the nitric–glycolic flowsheet was recommended for further testing. Based on the development of a roadmap for the nitric–glycolic acid flowsheet, Waste Solidification Engineering (WS-E) issued a Technical Task Request (TTR) to address flammability issues that may impact the implementation of this flowsheet. Melter testing was requested in order to define the DWPF flammability envelope for the nitric-glycolic acid flowsheet. The Savannah River National Laboratory (SRNL) Cold Cap Evaluation Furnace (CEF), a 1/12th scale DWPF melter, was selected by the SRR Alternate Reductant project team as the melter platform for this testing. The overall scope was divided into the following sub-tasks as discussed in the Task Technical and Quality Assurance Plan (TTQAP): Phase I - A nitric–formic acid flowsheet melter test (unbubbled) to baseline the CEF cold cap and vapor space data to the benchmark melter flammability models; Phase II - A nitric–glycolic acid flowsheet melter test (unbubbled and bubbled) to: Define new cold cap reactions and global kinetic parameters in support of the melter flammability model development; Quantify off-gas surging potential of the feed; Characterize off-gas condensate for complete organic and inorganic carbon species. After charging the CEF with cullet from Phase I CEF testing, the melter was slurry-fed with glycolic flowsheet based SB6-Frit 418 melter feed at 36% waste

  18. Effect of porosity, tissue density, and mechanical properties on radial sound speed in human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Eneh, C. T. M., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Töyräs, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Jurvelin, J. S., E-mail: jukka.jurvelin@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211, Finland and Diagnostic Imaging Center, Kuopio University Hospital, P.O. Box 100, Kuopio FI-70029 (Finland); Malo, M. K. H., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Liukkonen, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211 (Finland); Karjalainen, J. P., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Bone Index Finland Ltd., P.O. Box 1188, Kuopio FI-70211 (Finland)

    2016-05-15

    Purpose: The purpose of this study was to investigate the effect of simultaneous changes in cortical porosity, tissue mineral density, and elastic properties on radial speed of sound (SOS) in cortical bone. The authors applied quantitative pulse-echo (PE) ultrasound techniques that hold much potential especially for screening of osteoporosis at primary healthcare facilities. Currently, most PE measurements of cortical thickness, a well-known indicator of fracture risk, use a predefined estimate for SOS in bone to calculate thickness. Due to variation of cortical bone porosity, the use of a constant SOS value propagates to an unknown error in cortical thickness assessment by PE ultrasound. Methods: The authors conducted 2.25 and 5.00 MHz focused PE ultrasound time of flight measurements on femoral diaphyses of 18 cadavers in vitro. Cortical porosities of the samples were determined using microcomputed tomography and related to SOS in the samples. Additionally, the effect of cortical bone porosity and mechanical properties of the calcified matrix on SOS was investigated using numerical finite difference time domain simulations. Results: Both experimental measurements and simulations demonstrated significant negative correlation between radial SOS and cortical porosity (R{sup 2} ≥ 0.493, p < 0.01 and R{sup 2} ≥ 0.989, p < 0.01, respectively). When a constant SOS was assumed for cortical bone, the error due to variation of cortical bone porosity (4.9%–16.4%) was about 6% in the cortical thickness assessment in vitro. Conclusions: Use of a predefined, constant value for radial SOS in cortical bone, i.e., neglecting the effect of measured variation in cortical porosity, propagated to an error of 6% in cortical thickness. This error can be critical as characteristic cortical thinning of 1.10% ± 1.06% per yr decreases bending strength of the distal radius and results in increased fragility in postmenopausal women. Provided that the cortical porosity can be estimated

  19. The Influence A Crucible Arrangement On The Electrical Efficiency Of The Cold Crucible Induction Furnace

    Directory of Open Access Journals (Sweden)

    Smalcerz A.

    2015-09-01

    Full Text Available A big interest in application of cold crucible furnace (CCF for industrial, particularly metallurgical, processes has been observed in recent years. They are mainly utilised for melting of metal, glass and other materials. Analyses of processes that occur in such devices are performed; however, computer modelling is rarely applied. As a precise determination of the electromagnetic field distribution is essential for a proper analysis of processes in furnaces with cold crucibles, a complex 3D model development is necessary. In the paper, effects of a crucible design and current frequency on the efficiency of the induction furnace with cold crucible are presented. Numerical calculations were performed with the use of the Flux 3D professional software.

  20. Early shell crack detection technique using acoustic emission energy parameter blast furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Hyun; Lee, Sang Bum [RECTUSON Co.,Ltd., Changwon (Korea, Republic of); Bae, Dong Myung; Yang, Bo Suk [Pukyong National University, Busan (Korea, Republic of)

    2016-02-15

    Blast furnaces are crucial equipment for steel production. A typical furnace risks unexpected accidents caused by contraction and expansion of the walls under an environment of high temperature and pressure. In this study, an acoustic emission (AE) monitoring system was tested for evaluating the large-scale structural health of a blast furnace. Based on the growth of shell cracks with the emission of high energy levels, severe damage can be detected by monitoring increases in the AE energy parameter. Using this monitoring system, steel mill operators can establish a maintenance period, in which actual shell cracks can be verified by cross-checking the UT. From this study, we expect that AE systems permit early fault detection for structural health monitoring by establishing evaluation criteria based on the severity of shell cracking.

  1. Distribution of trace metals at Hopewell Furnace National Historic Site, Berks and Chester Counties, Pennsylvania

    Science.gov (United States)

    Sloto, Ronald A.; Reif, Andrew G.

    2011-01-01

    Hopewell Furnace, located approximately 50 miles northwest of Philadelphia, was a cold-blast, charcoal iron furnace that operated for 113 years (1771 to 1883). The purpose of this study by the U.S. Geological Survey, in cooperation with the National Park Service, was to determine the distribution of trace metals released to the environment from an historical iron smelter at Hopewell Furnace National Historic Site (NHS). Hopewell Furnace used iron ore from local mines that contained abundant magnetite and accessory sulfide minerals enriched in arsenic, cobalt, copper, and other metals. Ore, slag, cast iron furnace products, soil, groundwater, stream base flow, streambed sediment, and benthic macroinvertebrates were sampled for this study. Soil samples analyzed in the laboratory had concentrations of trace metals low enough to meet Pennsylvania Department of Environmental Protection standards for non-residential use. Groundwater samples from the supply well met U.S. Environmental Protection Agency drinking-water regulations. Concentrations of metals in surface-water base flow at the five stream sampling sites were below continuous concentration criteria for protection of aquatic organisms. Concentrations of metals in sediment at the five stream sites were below probable effects level guidelines for protection of aquatic organisms except for copper at site HF-3. Arsenic, copper, lead, zinc, and possibly cobalt were incorporated into the cast iron produced by Hopewell Furnace. Manganese was concentrated in slag along with iron, nickel, and zinc. The soil near the furnace has elevated concentrations of chromium, copper, iron, lead, and zinc compared to background soil concentrations. Concentrations of toxic elements were not present at concentrations of concern in water, soil, or stream sediments, despite being elevated in ore, slag, and cast iron furnace products. The base-flow surface-water samples indicated good overall quality. The five sampled sites generally had

  2. Study on Carbon Reduction of Guizhou Oolitic Hematite by Graphite in Muffle Furnace

    Science.gov (United States)

    Zhong, Zheng; Zhang, Jinzhu; Huang, Run; Li, Mingming; Wu, Jie

    2017-09-01

    Oolitic hematite is an important iron ore resource in China. The mixed powder of the Guizhou oolitic hematite, the graphite, and the calcium hydroxide was pressed in a cylindrical sample mold by a 16 Mpa pressure. The dried samples at 378K for 12h were reduced in a muffle furnace at the temperature between 1323K and 1473K. The microstructure and the metallization degree of the sample were studied by means of optical microscope and chemical analysis. The results show that the higher metallization degree of the Hezhang oolitic hematite was up to 80.2% at 1323K with carbon oxgen mole ratio 1.3, the metallization degree of the sample in a muffle furnace is lower than that in a microwave furrnace, the lower metallization degree of the sample should be concerned with that the redued metallic iron can be oxidized in the muffle furnace with the temperature cooling down very slowly.

  3. FURNACE 2. Toroidal geometry neutronic program system method. Description and users manual

    Energy Technology Data Exchange (ETDEWEB)

    Verschuur, K.A.

    1995-10-01

    FURNACE2 is a 3-dimensional neutron/photon-transport program system for toroidal geometries. It uses ray-tracing and double-differential reflection-and transmission-coefficients and flux-kernels to calculate the angular-flux spectra inside the torus of a fusion-reactor. FURNACE2 is an extended version of FURNACE, developed for application to the neutron-diagnostics at JET, which was supported financially by JET. It is used at JET to calculate the foil-activation for the KN2 diagnostics, the angular-fluxes on the lines of sight of the KN3 profile monitors, and general background fluxes and activation of the vessel. The program is used along with MCNP, combining the advantages of each of the programs and for mutual checks. (orig.).

  4. EVALUATION OF FLOW DISTRIBUTION IN THE PELLETIZING FURNACE THROUGH CFD AND EXPERIMENTAL VALIDATION AT SAMARCO

    Directory of Open Access Journals (Sweden)

    Maycon Athayde

    2014-12-01

    Full Text Available Samarco produces iron ore pellets thermally processed in Travelling Grate furnaces. This process is essential in order to obtain adequate mechanical strength to the pellets transportation and operation in the reduction reactors. All the mechanical properties of the agglomerates are obtained during the stage of firing, being a decisive step to pellet quality. Therefore, the velocity distribution of gas flow within this zone must be homogeneous. For this reason, it was developed a mathematical CFD model to characterize the gas flow in the burning zone, applying the equations of conservation of momentum, mass and energy. The validation of the model was obtained by measuring the temperatures inside the furnace. It was developed a wireless communication system in order to monitor continuously the evolution of the temperatures in the furnace.

  5. [Determination of trace cobalt in human urine by graphite furnace atomic absorption spectrometr].

    Science.gov (United States)

    Zhong, L X; Ding, B M; Jiang, D; Liu, D Y; Yu, B; Zhu, B L; Ding, L

    2016-05-20

    To establish a method to determine cobalt in human urine by graphite furnace atomic absorption spectrometry. Urine with 2% nitric acid diluted two-fold, to quantify the curve, graphite furnace atomic absorption spectrometric detection. Co was linear within 2.5~40.0 ng/ml with r>0.999. Spike experiment showed that Co received good recovery rate, which was 90.8%~94.8%. Intra-assay precisions were 3.2%~5.1% for Co, inter-assay precisions were 4.4%~5.2% for Co. The method by using graphite furnace atomic absorption spectrometr to determine urine Co was fast, accurate and with low matrix effect. It could meet the requirement in GBZ/T 210.5-2008.

  6. Role of adaptive heuristic criticism in cascade temperature control of an industrial tubular furnace

    Energy Technology Data Exchange (ETDEWEB)

    Zeybek, Zehra [Ankara University, Department of Chemical Engineering, Tandogan 06100, Ankara (Turkey)

    2006-02-01

    The purpose of this research is to improve and apply the multivariable control structure of an industrial furnace on the basis of the adaptive heuristic criticism (AHC). This algorithm is a three-layer feed-forward artificial neural network (ANN) that uses supervised learning with reinforcement in a unique topology. It shows how a system consisting of two neurone-like adaptive elements can solve a difficult learning control problem, i.e. the learning system consists of a single associative search element (ASE) and a single adaptive critic element (ACE). The task is to balance a pole that hinges on the manipulated variable by applying disturbance forces to the furnace. This approach to solve control problems of furnaces using AHC is discussed and compared with the results from the fuzzy temperature control of the system in this work. (author)

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

    Directory of Open Access Journals (Sweden)

    Jesser J. Marulanda-Durango

    2012-12-01

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

  8. Furnace veneering systems of special design help achieve energy reduction goals at Armco

    Energy Technology Data Exchange (ETDEWEB)

    Caspersen, L.J.

    1982-12-01

    A steel company conserves energy by veneering reheat furnaces with a ceramic fiber modular system. The furnace lining system incorporates several grades of veneering materials (modules, cements, coatings) whose application is matched to the exact conditions in the furnace. Zoned linings utilize a combination of grades of alumina-silica modules to achieve thermally efficient yet durable performance. High temperature cements exhibit good tackiness, easy module penetration and high strength retention after firing. A protective coating is sprayed in a thin layer over the modules and can be easily reapplied at a later date should it be necessary. Benefits include greater thermal control (temperature responsiveness and heating uniformity), less over-firing, less fuel use, and less heat loss. Fuel efficiency is increased by 20 to 50%.

  9. Automated information system for analysis and prediction of production situations in blast furnace plant

    Science.gov (United States)

    Lavrov, V. V.; Spirin, N. A.

    2016-09-01

    Advances in modern science and technology are inherently connected with the development, implementation, and widespread use of computer systems based on mathematical modeling. Algorithms and computer systems are gaining practical significance solving a range of process tasks in metallurgy of MES-level (Manufacturing Execution Systems - systems controlling industrial process) of modern automated information systems at the largest iron and steel enterprises in Russia. This fact determines the necessity to develop information-modeling systems based on mathematical models that will take into account the physics of the process, the basics of heat and mass exchange, the laws of energy conservation, and also the peculiarities of the impact of technological and standard characteristics of raw materials on the manufacturing process data. Special attention in this set of operations for metallurgic production is devoted to blast-furnace production, as it consumes the greatest amount of energy, up to 50% of the fuel used in ferrous metallurgy. The paper deals with the requirements, structure and architecture of BF Process Engineer's Automated Workstation (AWS), a computer decision support system of MES Level implemented in the ICS of the Blast Furnace Plant at Magnitogorsk Iron and Steel Works. It presents a brief description of main model subsystems as well as assumptions made in the process of mathematical modelling. Application of the developed system allows the engineering and process staff to analyze online production situations in the blast furnace plant, to solve a number of process tasks related to control of heat, gas dynamics and slag conditions of blast-furnace smelting as well as to calculate the optimal composition of blast-furnace slag, which eventually results in increasing technical and economic performance of blast-furnace production.

  10. Multipurpose furnace for in situ studies of polycrystalline materials using synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Hemant; Zuidwijk, Thim; Geerlofs, Nico; Offerman, S. Erik [Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD Delft (Netherlands); Wattjes, Alix C. [Electronic and Mechanical Support Division (DEMO), Delft University of Technology, Mekelweg 4, 2628 CD Delft (Netherlands); Amirthalingam, Murugaiyan [Materials Innovation Institute, Mekelweg 2, 2628 CD Delft (Netherlands)

    2009-12-15

    We report a multipurpose furnace designed for studies using synchrotron radiation on polycrystalline materials, namely, metals, ceramics, and (semi)crystalline polymers. The furnace has been designed to carry out three-dimensional (3D) x-ray diffraction measurements but can also be used for other types of synchrotron radiation research. The furnace has a very low thermal gradient across the specimen (<0.2 degree sign C/mm). Accurate determination of the temperature can be carried out by welding a thermocouple to the specimen. The furnace can be rotated over an angle of 90 degree sign in order to determine the crystallographic orientation of each individual grain. It is possible to follow growth kinetics of all grains in the illuminated volume of the specimen. The specimen environment can be controlled varying from vacuum (up to 10{sup -5} mbar) to gas or air filled. The maximum temperature of operation is 1500 degree sign C, with the possibility of achieving high heating (up to 20 deg. C/s) and cooling rates (up to 30 deg. C/s without quenching gas). 3D maps of the microstructure of the specimen can be generated at elevated temperatures by bringing the high-resolution detector close to the specimen. We show an example of a simulation of the heat affected zone during the thermal cycle of a weld in a transformation-induced plasticity steel carried out using the furnace. The unique characteristics of the furnace open possibility of new fields in materials research using synchrotron radiation.

  11. Subjects for achievement of blast furnace operation with low reducing agent rate

    Energy Technology Data Exchange (ETDEWEB)

    Ujisawa, Y.; Nakano, K.; Matsukura, Y.; Sunahara, K.; Komatsu, S.; Yamamoto, T. [Sumitomo Metal Industry Ltd., Kashima (Japan). Corp R& amp; D Labs.

    2006-12-15

    The technology which reduces the reducing agent rate by the improvement in the reaction efficiency of blast furnace leads to reduction of hot metal manufacturing cost, but also solution of recent CO{sub 2} emission reduction. The subjects for achievement of the blast furnace operation with low reducing agent rate were described on reduction measures of the carbon consumption and problem of the measures referring to the example of reducing agent rate of the present state blast furnace concerning blast operation and reactive improvement. And, carried out concrete measures were introduced in order to aim at the low reducing agent rate operation. The following results were obtained. 1) Since it has reached the already high reaction efficiency in present state blast furnace, it is not easy to attempt further reduction of the reducing agent rate. 2) The blast furnace use of high reactivity coke or reduced iron is equal level or over it in comparison with the reduction effect by the assumed blast operation in this paper. 3) The promotion of coke reaction load with the gasification is worried, when it aims at the low reducing agent rate operation by the high reactivity coke use. 4) It is estimated that the threshold also exists for the reducibility of competing ore, when it aims at the low reducing agent rate operation using the high reactivity coke. 5) The use of the low SiO{sub 2} sinter is effective for the improvement on the permeability in the blast furnace, when it aims at the low fuel rate operation. However, the new technology of the permeability improvement is desired, since there is a limit for low SiO{sub 2} of the sintered ore, when future raw material supply and demand is considered.

  12. Magnetic susceptibilities of minerals

    Science.gov (United States)

    Rosenblum, Sam; Brownfield, I.K.

    2000-01-01

    Magnetic separation of minerals is a topic that is seldom reported in the literature for two reasons. First, separation data generally are byproducts of other projects; and second, this study requires a large amount of patience and is unusually tedious. Indeed, we suspect that most minerals probably are never investigated for this property. These data are timesaving for mineralogists who concentrate mono-mineralic fractions for chemical analysis, age dating, and for other purposes. The data can certainly be used in the ore-beneficiation industries. In some instances, magnetic-susceptibility data may help in mineral identification, where other information is insufficient. In past studies of magnetic separation of minerals, (Gaudin and Spedden, 1943; Tille and Kirkpatrick, 1956; Rosenblum, 1958; Rubinstein and others, 1958; Flinter, 1959; Hess, 1959; Baker, 1962; Meric and Peyre, 1963; Rojas and others, 1965; and Duchesne, 1966), the emphasis has been on the ferromagnetic and paramagnetic ranges of extraction. For readers interested in the history of magnetic separation of minerals, Krumbein and Pettijohn (1938, p. 344-346) indicated nine references back to 1848. The primary purpose of this paper is to report the magnetic-susceptibility data on as many minerals as possible, similar to tables of hardness, specific gravity, refractive indices, and other basic physical properties of minerals. A secondary purpose is to demonstrate that the total and best extraction ranges are influenced by the chemistry of the minerals. The following notes are offered to help avoid problems in separating a desired mineral concentrate from mixtures of mineral grains.

  13. Alcohol increases hypnotic susceptibility.

    Science.gov (United States)

    Semmens-Wheeler, Rebecca; Dienes, Zoltán; Duka, Theodora

    2013-09-01

    One approach to hypnosis suggests that for hypnotic experience to occur frontal lobe activity must be attenuated. For example, cold control theory posits that a lack of awareness of intentions is responsible for the experience of involuntariness and/or the subjective reality of hypnotic suggestions. The mid-dorso-lateral prefrontal cortex and the ACC are candidate regions for such awareness. Alcohol impairs frontal lobe executive function. This study examined whether alcohol affects hypnotisability. We administered 0.8 mg/kg of alcohol or a placebo to 32 medium susceptible participants. They were subsequently hypnotised and given hypnotic suggestions. All participants believed they had received some alcohol. Participants in the alcohol condition were more susceptible to hypnotic suggestions than participants in the placebo condition. Impaired frontal lobe activity facilitates hypnotic responding, which supports theories postulating that attenuation of executive function facilitates hypnotic response, and contradicts theories postulating that hypnotic response involves enhanced inhibitory, attentional or other executive function. Copyright © 2013. Published by Elsevier Inc.

  14. Respiratory hazard from removal of ceramic fiber insulation from high temperature industrial furnaces.

    Science.gov (United States)

    Gantner, B A

    1986-09-01

    Ceramic fiber insulation is being used increasingly as a refractory lining for heat treating and preheating furnaces in the iron and steel industry. This is largely due to its superior thermal resistance per unit thickness when compared to insulating fire brick, which was the previous mainstay of refractory linings. Although toxicity data to date have found these ceramic fibers to be innocuous, recent studies have shown the fibers to devitrify and undergo partial conversion to cristobalite when exposed to elevated temperatures. This paper presents the exposure hazards to cristobalite found during the removal of various brands of ceramic fiber insulation from heat treat furnaces and the extent of fiber transformation to cristobalite.

  15. Experimental and empirical technique to estimate energy decreasing at heating in an oval furnace

    Directory of Open Access Journals (Sweden)

    A. A. Minea

    2012-10-01

    Full Text Available In this paper an experimental and empirical methods are proposed to estimate the heat transfer enhancement in industrial heating processes in oval furnaces. An investigation was conducted to study the suitability of inserting radiant panels of different positions and radiation surface. Two case studies were considered. The maximum energy saving was obtained for case 5: 32,89 % off from the standard experiment (with no panels. The minimum energy saving was obtained for case 10: 11,72 % off from the standard experiment (with no panels. Finally, based on the results of this study, a correlation was developed to predict the inner configuration of an oval furnace.

  16. Waste-gas systems for modern furnaces/fireplaces. Abgasanlagen fuer moderne Feuerstaetten

    Energy Technology Data Exchange (ETDEWEB)

    Hoeppner, J.; Postenrieder, E.

    1984-01-01

    Design of an off-gas system for chimney-equipped furnaces or fireplaces of all kinds has an essential influence on function and economic efficiency of gas- and oil furnaces. This book therefore deals with the most important questions and functions of chimneys. Relevant standards are explained in the sections chimney engineering and joining pieces. A simplified dimensioning of chimneys is also dealt with as well as fittings an accesory parts for chimneys especially regulations for application, installation and utilization of these fittings or auxiliary parts. Failures and disturbancies of operation are described, hints on how to repair them are given. Rules, regulations, terms and tables complement the explanations.

  17. Identification of possible non-stationary effects in a new type of vortex furnace

    Science.gov (United States)

    Shadrin, Evgeniy Yu.; Anufriev, Igor S.; Papulov, Anatoly P.

    2017-10-01

    The article presents the results of an experimental study of pressure and velocity pulsations in the model of improved vortex furnace with distributed air supply and vertically oriented nozzles of the secondary blast. Investigation of aerodynamic characteristics of a swirling flow with different regime parameters was conducted in an isothermal laboratory model (in 1:25 scale) of vortex furnace using laser Doppler measuring system and pressure pulsations analyzer. The obtained results have revealed a number of features of the flow structure, and the spectral analysis of pressure and velocity pulsations allows to speak about the absence of large-scale unsteady vortical structures in the studied design.

  18. Identification of possible non-stationary effects in a new type of vortex furnace

    Directory of Open Access Journals (Sweden)

    Shadrin Evgeniy Yu.

    2017-01-01

    Full Text Available The article presents the results of an experimental study of pressure and velocity pulsations in the model of improved vortex furnace with distributed air supply and vertically oriented nozzles of the secondary blast. Investigation of aerodynamic characteristics of a swirling flow with different regime parameters was conducted in an isothermal laboratory model (in 1:25 scale of vortex furnace using laser Doppler measuring system and pressure pulsations analyzer. The obtained results have revealed a number of features of the flow structure, and the spectral analysis of pressure and velocity pulsations allows to speak about the absence of large-scale unsteady vortical structures in the studied design.

  19. Reduction disintegration mechanism of cold briquettes from blast furnace dust and sludge

    Directory of Open Access Journals (Sweden)

    Leandro Rocha Lemos

    2015-07-01

    Full Text Available It is important to understand the reduction disintegration mechanism in ferriferous burden that is used in blast furnaces. The behavior of this burden in the granular zone of this metallurgical reactor is important for smooth operation. The objective of this work was to prepare cold self-reducing briquettes using blast furnace dust and sludge and binders and compare the reduction disintegration index (RDI of these agglomerates with conventional ferriferous burdens such as pellets, sinter and iron ore. In the present work, 25 different mixtures were prepared to produce briquettes in two geometries: pillow and cylindrical. The RDI value was determined for the briquettes that passed the tumbling test.

  20. Minimizing Energy Cost in Electric Arc Furnace Steel Making by Optimal Control Designs

    Directory of Open Access Journals (Sweden)

    Er-wei Bai

    2014-01-01

    Full Text Available Production cost in steel industry is a challenge issue and energy optimization is an important part. This paper proposes an optimal control design aiming at minimizing the production cost of the electric arc furnace steel making. In particular, it is shown that with the structure of an electric arc furnace, the production cost which is a linear programming problem can be solved by the tools of linear quadratic regulation control design that not only provides an optimal solution but also is in a feedback form. Modeling and control designs are validated by the actual production data sets.