JAPAN TAPPI JOURNAL
Online ISSN : 1881-1000
Print ISSN : 0022-815X
ISSN-L : 0022-815X
Volume 51, Issue 11
Displaying 1-16 of 16 articles from this issue
  • [in Japanese]
    1997 Volume 51 Issue 11 Pages 1617
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
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  • Tetsuro Kojima
    1997 Volume 51 Issue 11 Pages 1618-1625
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    The pulp and paper industry has been one of heavy energy-consuming industries. Because of that, it has been working very hard to reduce its energy consumption and to improve its efficiency, especially since the notorious oil price hike.
    As the result, the ratio of a cost for buying energy in the total production cost has reduced to one third of that 15 years ago.
    Recently, energy conservation is worked out in the flame work of global environment, not just as a profit-oriented concern. Japan Paper Association announced a guideline of reducing the energy cost by 10% based on that in 1990 by 2010, defining benchmarks for major four products.
    Then, what should we do. They are : improving operating efficiency, utilizing waste heat energy, power generation from waste, combined power generation, and converting processes to less energy incentive ones.
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  • Masaaki Bannai
    1997 Volume 51 Issue 11 Pages 1626-1633
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    Cogeneration systems (CGS) have been widely accepted in the market, and various modified systems are in operation. Among them, a gas turbine repowering system is very interesting, in which a gas turbine generator (GT) is added to an existing combined power system of a boiler and a steam turbine (ST). In this system, the exhaust heat of GT is directed to ST, is used as an additional combined cycle, and the overall heat efficiency is improved.
    The characteristics of this repowering are : energy saving by 10-30 percent by step-by-step (cascade) energy use, less emission of carbon dioxide and nitrogen oxides, additional power generation by GT and total energy saving in a mill.
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  • Kouichi Chiba
    1997 Volume 51 Issue 11 Pages 1634-1642
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    This paper describes outline information on existing and advanced technologies regarding high efficiency gas turbine (GT) power plant using aero-derivative GT for the purpose of informing companies which are planning to provide their GT power generation plants in the near future as Independent Power Producers (IPP) or their own power generation facilities. To increase thermal efficiency in the power plant is essential not only for reducing fuel in combustors but also for reducing CO2 in exhaust gas. Demands for and regulations regarding reduction of CO2 will be strengthened year by year for environmental protection in the world. For this demand, the technologies has been progressing day by day. In addition, 60% efficiency power generation systems for the next century have been studied and are introduced here. The contents are as follows ;
    1. Outline of Aero-derivative GT :
    Introduction of the aero-derivative GT and its features such as being compact, light and highly efficient.
    2. Progress in/of advanced technologies for increased efficiency of aero-derivative GT : Introduction of GT blade materials and cooling methods for blades.
    3. System technologies for high efficiency of power generation :
    Explanations of basic ideas for a highly efficient system such as the Regeneration System, Reheating System, Intercooling System.
    4. Combined Cycle System :
    Introduction of operational combined-cycle plants.
    5. Mixed Gas-Steam Cycle Systems :
    The following kinds of these systems are introduced.
    ·Steam-injected GT System (STIG)
    ·Flexible Electric Co-generation System (FLECS)
    ·Intercooled Steam-injected Cycle System (ISTIG)
    ·Humid Air Turbine Cycle System (HAT)
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  • Kazumitsu Takeda
    1997 Volume 51 Issue 11 Pages 1643-1648
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    In Japan, municipal waste amounts to 50 million tons a year and its incineration ratio at present is approximately 74%. However, the generation of electricity from firing municipal waste is limited because of its characteristics ; namely municipal waste vary in shape and are apt to rot or decompose and emit odor. Therefore, they are not suitable for transportation or storage.
    Refuse derived fuel (RDF) for municipal waste is the pelletizing one made from municipal waste. Hard and dry RDF with calcium compounds can be stored for a long time, handled and transported easily.
    Moreover, high-efficiency power generation is possible by gathering RDF manufactured from local communities and applying a circulating fluidized bed boiler with external circulation system for its combustion.
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  • Yoji Ogaki
    1997 Volume 51 Issue 11 Pages 1649-1657
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    NKK has started operation of following pilot plants at NKK Environment R&D Center located in NKK Tsurumi Works, Yokohama, Japan in September, 1996. These plants represent NKK's response to the need from the society for recycle of various wastes so that such imminent problems are solved as limitation of landfill sites, rapid increase of municipal wastes and air-contamination with dioxins. The Center consists of the following plants.
    1. the slag resistance electric furnace for melting ash from municipal waste incinerator turns ash into slag to be used in road construction and so on, while stabilizing heavy metals originally contained in the ash,
    2. the direct waste melting furnace burns combustibles and non-combustibles with the help of coke, while melting the residue into slag, all in one furnace,
    3. the waste-to-solid fuel (RDF) processing facility enables the waste to be used as fuel at cement kilns and power generation plants, so as to avoid the Dioxins problems in small scale incinerators, and
    4. the waste sorting/recovery system sorts out glass bottles, cans and plastic containers respectively for re-use, consisting of the original air-assisted separator, color-sorter for glass bottles and other components.
    In addition, NKK has also been operating the facility for waste plastics recycling in a blast furnace at NKK Keihin steal Works since October, 1996, injecting industrial waste plastics into the blast furnace as raw material. Now expectations are high for the facility in the area of processing waste container and package plastics.
    In this report, these plants are introduced in detail, as well as NKK's research and development in the waste recycling technologies.
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  • Noriyasu Ogi
    1997 Volume 51 Issue 11 Pages 1658-1664
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    UBE Industries is doing business in the various area of industries such as machinery, engineering, chemistry, cement and coal. By combining technologies and know-how in these areas, UBE could have a unique core technology for its environmental business. Some of its new developments are introduced.
    1. SWM (Solid Water Mixture) : Converting municipal waste into slurry for fuel and chemical materials.
    2. Dewatered sewage sludge puffing system : Mixing slurry with CWM (coal water mixture) for gasification.
    3. ISV (In-Situ Vitrification) : In-Situ Vitrifying polluted soil and waste.
    4. Concentration and recovery system for waste nitric soda.
    5. RDF power generation : Converting municipal waste to RDF for power generation.
    6. Environmental industrial complex.
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  • Experiences & Ideas for New Processes and Equipments
    Takeshi Kanazawa
    1997 Volume 51 Issue 11 Pages 1665-1678
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    Recycling Pulp is divided broadly into two categories, one is brwon grade pulp for paper board and the other is deinked pulp for fine papers including news paper. Use of those pulp have been expanded for reducing product cost as well as protection of global enviroment. The cost reduction have been mainly developped by a mean of energy saving. Current specific power consumption of brown grade recycling pulp is about 5.5 kW/Ton in spite of 6.5-7.0 kW/Ton in the past, and is still reducing. That of deinked ulp, however, is extremely increasing due to complication of the processing system, because of demand of high grade quality, increase of various contaminants such as stickies and UV printed etc.. Current specific power consumption of deinked pulp is about 20-30 kW/Ton, and is still increasing. Considering those situation, energy saving of recycling pulp is still one of the main subject to be discussed among paper manufacturing engineers. In the past, energy saving has been directly approached to reduce electlicity, steam and etc.. It is now, however, approached by means of both hard and soft technologies. It is a typical example for development of hard technology that stock preparation equipment is changing to a machine having a combined function from a simple function machine. And for development of soft technology, improvement of stock yield, paper machine productivity, sticky removal, filtrate cleaning, man power saving, and use of low grade furnish are being studied.
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  • Result and Improvement on the MF Screen Application
    Masakazu Eguchi
    1997 Volume 51 Issue 11 Pages 1679-1688
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    In the conventional secondary fiber system and Kraft pulp system, the reject rate must be larger to keep the higher screening efficiency, and the shives, fiber bundles in the reject stock must be also deflaked to maintain the higheryield.
    In consequence, the screen system, particularly thereject line, will go to larger and more complicated scale, and it will lose much energy.
    The MF Screen, developed by Ishikawajima Industrial Machinery Co., is the revolutionary device which can enormously reduce the energy consumption and extensively simplifies the conventional screen system, while keeping the screening efficiency of the accept stock. The MF Screen can reduce both energy and initial cost by about 50 percent compared with the conventional screen system.
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  • Energy Abatement and Modernization for Washing Process
    Ikuro Seino, Chiaki Kawakami
    1997 Volume 51 Issue 11 Pages 1689-1697
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    Ahlstrom has developed Drum Displacer WasherTM (DD washer), which is a new generation washer having up to 4-washg stages in one unit. Low Consistency Drum DisplacerTM (LCDD) and Meddium Consistency Drum DisplacerTM (MCDD) have shown excellent washing performance in brownstock wash, post-oxygen wash and bleach systems.
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  • Tadatoki Yano
    1997 Volume 51 Issue 11 Pages 1698-1705
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    Several problems intrinsic to a roll nip press can be solved by a shoe press. A shoe press has a wide nip width, six to seven times as that of a roll press, which gives lower nip pressure and higher water drainage during the operation.
    By installing a shoe press, improved water drainage at a press results in higher dryness after the press section, and makes it possible to increases its machine speed by 20-30 percent with the same numbers of dryers. The expected better sheet strength will reduce frequency of sheet breaks, and will result in higher machine efficiency.
    A sheet dewatered by a shoe press has a relatively uniform fiber composition in the zdirection (thickness), which makes operation at drying and size-press coating far less complicated. The control system itself can be simplified.
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  • Shigeru Sekine
    1997 Volume 51 Issue 11 Pages 1706-1713
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    There are so many numbers and capacity of motors and drives applied to paper making machinery in pulp and paper industries. The loads such as fans, pumps, and blowers usually require the constant speed rotation of motors conventionally and have been driven by adjustable speed drives by inverters for energy savings recently. On the other hand the loads such as paper machines, winders and coaters usually require the adjustable speed rotation of motors and drives, driven by DC motors and drives, conventionally, and have been driven by AC drives for better maintainability, not for energy savings.
    This article describes the energy savings effect on the latter load (paper machines, winders and coaters), which conventionally require adjustable speed rotation of motors, comparing AC drives with DC drives.
    The AC drives for a winder are highly precise digital vector controlled PWM inverters, which have a common DC converter for an unwinder and drums, and the motors are rigid and simple structured squirrel cage induction motors. The inverter for an unwinder is tension regulated and the inverter for a drum is speed regulated. When a winder is driven by AC drives whose converter is common for inverters, the power for tension is fed from the inverter for drum and powered back from the inverter for unwinder without power feeding from power source. When a winder is driven by DC drives, the power for tension is fed from the converter for drum and powered backed from the converter for unwinder. DC drive feeds the field power of DC motors and generates loss. And the efficiency of the induction motor is higher than that of DC motor. Total efficiency of AC drives is higher than that of DC drives. The example figures are shown.
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  • Noboru Tezuka
    1997 Volume 51 Issue 11 Pages 1714-1727
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
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  • Gyosuke Meshitsuka, Yuji Matsumoto, Kenji Iiyama, Shuji Hosoya, Hirosh ...
    1997 Volume 51 Issue 11 Pages 1728-1753
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
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  • Yoshiki Kanamori
    1997 Volume 51 Issue 11 Pages 1754-1757
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
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  • Relationship between enzyme activities of fungi having ability for degradation of dioxins and degradation of 2, 7-Dichlorodibenzo-p-Dioxin and an improved screening method of fungi having
    Kazutaka Itoh, Hiroki Ohkawa, Sanro Tachibana, Tatuya Hirabayashi
    1997 Volume 51 Issue 11 Pages 1759-1768
    Published: November 01, 1997
    Released on J-STAGE: November 19, 2009
    JOURNAL FREE ACCESS
    The time-course of the activities of cumulative lignin peroxidase (LiP), cumulative managanase peroxidase (MnP), and cumulative laccase (Lac) from the five fungi having ability for degradation of 2, 7-Dichlorodibenzo-p-dioxin (2, 7-DCDD) was measured in connection with the degradation rate of 2, 7-DCDD with five fungi. The activity of cumulative Lip of a fungus was higher, the degradation rate of 2, 7-DCDD was higher. Correlation between the activity of cumulative Lip and the degradation rate of 2, 7-DCDD was observed. However, the activities of cumulative MnP and cumulative Lac were not correlated to the degradation rate of 2, 7-DCDD.
    From the results obtained above, we found the improved screening method of fungi having higher ability for degradation of dioxins. First, screening of fungi having ability for decolorization of dye was carried out by using Remazol brilliant blue R, a kind of dye, as an indicator. In the second screening, fungi having ability for higher activity of cumulative Lip were selected. By using this method, three fungi named 25, 65, and E having higher ability for degradation of 2, 7-DCDD was obtained by the screening from natural world.
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