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No. 33 FEB. 2015
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<Feature-Ⅰ>Natural Resources and Energy
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Resources Trend and Use of Direct Reduced Iron in Steelmaking Process
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Dr. Hidetoshi TANAKA
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Expectations are rising for new ironmaking processes that can utilize a wide variety of materials and fuels and also are environmentally friendly. The direct reduction (DR) process is one such ironmaking process that can substitute for blast-furnace (BF) ironmaking. This new process can utilize inexpensive shale gas, which enables its plants to be built at various locations. The DR process may be adapted for coal-based processing, which will contribute to the stable supply of direct reduced iron (DRI). This paper outlines the DR technologies developed by Kobe Steel and includes a survey on the contribution of DRI as a substitute for scrap used in electric arc furnaces (EAFs) and as a burden material in BFs.
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Beneficiation Plants and Pelletizing Plants for Utilizing Low Grade Iron Ore
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Tsutomu NOMURA, Norihito YAMAMOTO, Takeshi FUJII, Yuta TAKIGUCHI
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Recently, the grade of iron ore deposits has deteriorated and further development of low grade deposits is desired. Presently, the most effective and often followed route taken to utilize such deposits is the provision of beneficiation plants for upgrading iron ore and pelletizing plants for agglomerating. Kobe Steel has much experience in constructing both beneficiation and pelletizing plants and has its own pelletizing process (KOBELCO pelletizing system). This paper contains general information on beneficiation and pelletizing plants, including future expectations for them, and introduces the latest activities in connection with the KOBELCO pelletizing system, with a view to the future.
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Application of Coke Oven Gas to MIDREX® Process
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Noriaki MIZUTANI, Takashi KISHIMOTO, Norihide MAEDA
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The MIDREX® process runs without coke, emits less CO2 and thus is gathering attention as an alternative process for blast furnace ironmaking. To expand business opportunities, a study has been conducted on the use of coke oven gas (COG) so as to diversify the MIDREX process. The study has resolved most of the technical issues for commercialization, as reported in this paper
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Evaluation of Spontaneous Combustion in Stockpile of Sub-bituminous Coal
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Dr. Haeyang PAK, Toshiya TADA, Naoki KIKUCHI, Takuo SHIGEHISA,
Toru HIGUCHI, Dr. Seiichi YAMAMOTO
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Spontaneous combustion in coal stockpiles is one of the problems encountered when utilizing coals such as subbituminous coal and lignite that contain highly volatile matter. A method has been developed for simulating the spontaneous combustion in coal stockpiles. This method involves unsteady analysis taking into account the flow behavior of air flowing through the pile, low-temperature oxidation behavior of coal in the pile, evaporation, absorption and desorption behaviors of moisture in the coal. The simulation enables the evaluation of the temperature change in a coal stockpile without any largescale temperature measurement. The simulation results show that the heat tends to be generated at the foot of each stockpile where the breathability is high. It has also been confirmed that the stockpile of sub-bituminous coal exhibits a faster temperature rise because the coal has an oxidation reactivity higher than that of bituminous coal.
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| 28 |
Mine-mouth Power Generation System Based on Upgraded Brown Coal (UBC®)
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Takeo KASHIWAGI, Hiromichi ISHINO, Takashi TAKAGI, Ken HIROSE
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Currently, the use of lignite (also referred to as "brown coal") is limited to mine-mouth power generation. The high moisture content in lignite causes its powergenerating efficiency to be considerably lower than that achieved by bituminous coal. Kobe Steel has developed a process for producing Upgraded Brown Coal (UBC®) by applying a unique slurry dewatering technology. A study has been conducted using the UBC made from Indian lignite to verify its applicability in improving the efficiency of mine-mouth power generation. The results confirmed that UBC-based power generation is superior to the existing lignite-fired power generation.
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| 34 |
Energy Saving Air-Separation Plant Based on Exergy Analysis
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Masaaki TANIGUCHI, Hitoshi ASAOKA, Toshiyuki AYUHARA
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Air-separation units (ASUs) are widely used in various industries such as steel, chemistry and electronics. They require a very large amount of energy. Therefore, their energy consumption needs to be reduced further in order to help stop global warming. Shinko Air Water Cryoplant (SAC) has been conducting collaborative research with the University of Tokyo to develop a process that can greatly reduce the power consumption. The concept of "exergy" was introduced in this research as an index for evaluating the energy efficiency of a process. As a result, a new single-column rectification process has been developed and verified as requiring approximately 30% less energy than does the conventional double-column rectification process.
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Fabrication and Properties of Forged Rings made of Modified 9Cr-1Mo-V Steel for High-temperature and High-pressure Reactor
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Tomoya SHINOZAKI, Tetsuya KOMURA, Nobuyuki FUJITSUNA,
Hiroki NAKASHIMA, Masato YAMADA, Tomoaki NAKANISHI
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Recently, new processes have been developed for more efficiently cracking extra-heavy oil and liquefying coal. These new processes involve reactors, each operating at a temperature around 500°C. Modified 9Cr-1Mo-V steel, with its excellent high-temperature performance, is thus a candidate material for these reactors. A heavywall reactor is composed of a forged shell-ring made from an ingot weighing over 190 tonnes, and its wall thickness at the time of heat treatment becomes 300mm or greater. In the forging of modified 9Cr-1Mo-V steel made from an ingot weighing 30 tonnes, however, internal defects are likely to be formed; and the occurrence of casting defects become more serious as the size of the ingot increases, according to reports. Therefore, when producing forgings exceeding 100 tonnes, the internal quality of the forgings must be checked. An evaluation test was conducted; it verified that the heavy-wall shell ring made of modified 9Cr-1Mo-V steel exhibits no internal defects and has excellent material properties, satisfying the ASME requirements.
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<Feature-Ⅱ> MONODZUKURI (Art of Design and Manufacturing)
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Technologies for Process Design of Titanium Alloy Forging for Aircraft Parts
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Takashi CHODA, Dr. Hideto OYAMA, Shogo MURAKAMI
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Titanium alloys are widely used for aircraft parts, thanks to their high specific strength. It is important, in dealing with titanium alloy forgings, to control the history of temperature and plastic strain in order to obtain desired microstructures and mechanical properties. This paper introduces an example in which a process is designed using finite element method (FEM) analysis for ß-processed forgings of a jet engine disk made of Ti-6246 alloy.
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Efficient Inspection for Gas Pipes by Infrared Thermography
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Hideki ENDO, Takuya KUSAKA
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Gas pipe failure caused by inner corrosion defects is one of the risk factors for the unscheduled shutdown of a plant. The pipes must be inspected to reduce the risk, but this requires a great amount of time and money, since gas pipes are quite long. This research proposes a screening method for the efficient inspection of gas pipes caused by aqueous corrosion. This screening method consists of three stages and includes thermographic and ultrasonic testing. We have developed new thermographic testing to find sludge in a pipe and to measure its wall-thinning distribution. The measuring principle and examples of the application of thermographic testing are introduced in this paper.
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Machining Technology for Large Impellers of Centrifugal Compressors
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Toru KAINO
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The impellers of centrifugal compressors are becoming larger, requiring machining efficiency to be improved in accordance with the characteristics of 5-axis machining centers and work shapes. Now, the machining time has been reduced by using contour machining, a cuttingresistance-leveling system and a method for predicting chatter vibrations. This paper describes the recent measures taken to improve the machining of large impellers.
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Automatic Welding System for Crawler Crane Top and Bottom Booms
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Akira OKAMOTO, Masatoshi HIDA, Tsutomu OONE, Takemasa YAMASAKI,
Tatsuro ASANO, Toshifumi KOBAYASHI
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An automatic welding system for upper and lower booms was developed at KOBELCO CRANES CO., LTD., aiming at stabilizing production capacity, achieving consistently high quality and increasing flexibility for varying work volumes. A technology was developed for reducing the man-hours spent in teaching tasks having to do with the weld lines of lattice pipes. Also developed was a sensor technology that enables copy welding by reliably detecting welding lines even during large-current welding, which generates large amounts of fume and spatter, and during welding on a specular reflection surface. This paper introduces these technologies.
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| 70 |
Global e-learning System for Technical Support Engineers
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Youichirou Sou, Masashi YAMAKOSHI, Yoshihiro MURAKAMI
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With the increasing globalization of business, Japanese manufacturers are trying to strengthen the system for managing after-sales service activities at overseas branches so as to make themselves stand out from competitors. For this purpose, securing and training engineers for technical support is one of the most important issues. KOBELCO CONSTRUCTION MACHINERY CO., LTD. (KCM), one of the most globalized companies in the Kobelco group, has deployed an e-learning service for training support engineers since 2009. Having released the e-learning service for Japanese engineers first, KCM has extended it to the overseas branches since 2011, and at the end of 2013, in approximately 20 countries, the e-learning service was effectively being used as a common platform for educating engineers. Through those experiences, this paper discusses the possibilities and challenges in the use of IT for grooming after-sales service technical support engineers in the overseas branches.
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| 74 |
Evaluation System for Thin-Film Oxide Semiconductor Using µ-PCD
- Effectivity of Measuring Technique -
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Yuki NONOMURA, Keizo YAMASHITA, Futoshi OJIMA, Dr. Tomoya KISHI,
Kazumasa TOKUDA, Dr. Toshihiro KUGIMIYA
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A novel system has been developed for evaluating thinfilm oxide semiconductors using a µ-PCD (Microwave Photo Conductivity Decay) method. Variations of the mobility and Vth shift are issues in the manufacturing process of oxide semiconductors. To resolve these issues, an evaluation technique has been established. In addition, the mura (unevenness) of film quality on substrate has become another issue as the substrate size increases. It has been demonstrated that mapping measurement is effective in resolving this issue.
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