Ebara Engineering Review

by Satoshi SEKIZUKA, Sumio SAITO, & Arinobu SATO
A comparative study was made on the performance of two actual wind turbine generator systems, both being asynchronous but each with a different control system (different power output and speed control). It was found that fluctuations in the electric current matched power output fluctuations for both systems. As for wind speed fluctuations, differences were found depending on the type of control system. The following discusses this study in detail.

Keywords
Wind turbine, Wind turbine generator system, Propeller type wind turbine, Power control, Constant speed wind turbine, Variable speed wind turbine, Wind speed, Induction generator, Power curve, Acoustic noise

by Chikara MAKINO, Takashi ISOBE, & Ryota MIKI
A variable-speed, shallow-well pump, equipped with an inverter-driven DC brushless motor, was developed. This pump features an estimated constant end-pressure control for maximum energy conservation and noise reduction (about a 55% saving in energy and 7 - 10 dB (A) in noise reduction, compared to the case of conventional such pumps). Compared to induction motor equipped conventional models, its new hydraulic parts enable the pump performance characteristics of this pump suitable for the control pressure and applied flow rate ranges. Safety in the water quality is further improved by compliance with the leachate performance standard. This pump can also easily replace existing conventional such pumps as its dimensions and suction-discharge diameters are made compatible with conventional types.

Keywords
Variable speed, Inverter, End pressure, Noise reduction, Energy conservation, Constant speed, Compatibility, Fuzzy control, Excessive frequency of starting, Cascade pump

by Toyoji SHINOHARA, Akira TANAKA, & Tadakazu NISHIKAWA
Three types of PFC-containing waste gas treatment systems (combustion, catalyst and fluoride fixation types) have been developed and are now market-available. The fluoride fixation type produces no drainage. These systems are for use by semiconductor and liquid crystal manufacturing industries who use PFCs in etching and cleaning processes. The following outlines these systems.

Keywords
Par-fluoro compounds, Global warming effect gas, Catalyst type waste gas treatment system, Fluoride fixation type waste gas treatment system, Decomposition by catalyst, Oxidization and decomposition by heating, Fluoride fixation absorber, Reactor, Heater, Toxic gas

by Akira TANAKA, Yoko SUZUKI, & Tomonori OHASHI
A 200 mm wafer ambient control box, which corresponds to the SMIF system, has been developed. This ambient control box is a wafer storage-transporting container, capable of minimizing particle contamination, molecular contamination, as well as humidity. The following outlines some results of the development carried out under grant from the New Energy and Industrial Technology Development Organization (NEDO) of Japan, including data on a 300 mm wafer ambient control box.

Keywords
Semiconductor, Wafer, Contamination control, SMIF system, Clean environment, HALCA project, Out gas, PWP test, Chemical filter, Airborne molecular contaminants

by Masao MURAI, Kazuo KINOSHITA, & Keitaro TADA
A compact co-generation system, equipped with a PEFC (Polymer Electrolyte Fuel Cell) which uses ADG (Anaerobic Digestion Gas) as fuel, has been developed and tested. Test results were favorable, indicating that this system used at a sewage treatment plant would reduce energy consumption, effectively make use of ADG produced during sludge treatment, make available electric power as well as hot water, and cause less impact on the environment.

Keywords
Polymer Electrolyte Fuel Cell (PEFC), Sewage plant, Digestion sludge, Self-sufficiency rate, Anaerobic Digestion Gas refining equipment (ADG refining equipment), EBARA BALLARD CORPORATION, Residential 1 kW PEFC co-generation system

by Hiroshi UDAGAWA
EBARA's ventilation system for the Seki Tunnel on Route 25 has been modified to minimize life cycle cost. This was done by replacing the main parts of the system's jet fans with stainless steel material which feature better corrosion resistance.

Keywords
Seki Tunnel, Jet fan, Corrosion, Stainless steel, Life cycle cost, Tunnel Ventilation

by Akira MOCHIZUKI, & Jiro HORISAWA
A tunnel facilities management and control system had been developed for the Toyama Office of the Ministry of Land, Infrastructure and Transport, Government of Japan. Mangement and control can now remotely done via the Web for tunnel ventilation, measurement, fire fighting, defrosting, water drainage, etc. Servers are installed in respective offices for totalized facility data access, including log books and equipment drawings.

Keywords
Remote monitoring and control system, Facility data system, Tunnel ventilation, Emergency facilities, Web

by Shinichiro CHIBA, Yasuhiro ANAZAWA, & Takeru MATSUBARA
A fluidized-bed incineration system , featuring treatment of paper sludge, incineration of reject from paper recycling, use of excess heat from incineration to generate steam for use within the factory, is being used at a paper mill of Takasago Paper Co., Ltd. This system is achieving a reduction in waste output from the mill, a saving in energy consumption and waste treatment cost, as well as minimized impact on the environment. The following outlines this system.

Keywords
Fluidized-bed incinerator, Industrial waste, Paper factory, Paper sludge, Reject, Waste heat, Environmental impact

by Takeshi UOZUMI, & Takeshi MIYATAKE
EBARA's rotary-kiln firing system (treatment capacity: 36.24 tons/24 hours×1 furnace) has been installed at the Nisio Plant of Aisin Seiki Co., Ltd. for treating industrial waste (sludge-including waste paint, waste oil and waste liquid) produced at this plant. Excellent feedback of the system's operation is reported and treatment results indicate that local environmental standards are being sufficiently met. In particular, dioxin emission is kept considerably below the 0.1 ng-TEQ/m3(NTP) local standard. Excess heat from the flue gas is effectively used to supplement combustion heat in the kiln.

Keywords
Rotary-kiln, Industrial waste, Dioxins, DCS (Distributed Control System), Catalytic reaction tower

by Masaru KOJIMA, Kenichi KUROKAWA, Hironori NINOMIYA, & Tetsuo UCHIDA
A new type photovoltaic power generation system has been developed for use at subway stations. This system features a compact, transformer-less power conditioner and computerized data analysis and retrieval. This system has been installed at Kobe's Sogoundo Koen Station. The following introduces and discusses this system.

Keywords
Photovoltaic module, Photovoltaic array, Support structure PV module, Foundation for photovoltaic array, Transformer-less, Power conditioner, Data measurement system, Software of data measurement, Trend screen, Display panel of generating data

by Motohiko NOHMI, Akira GOTO, Tatsuyoshi KATSUMATA, Yuka IGA, & Toshiaki IKOHAGI
The cavitation flow in a low specific speed centrifugal pump was measured in detail. Pressure transducers were installed in impeller vanes and unsteady pressure distribution over the pressure and suction sides was studied. Cavitation characteristics were photographed along the axial direction in the inlet volute casing and front shroud. Cavitation flow in the pump was numerically analyzed using a locally homogeneous cavitation model of a compressible air-vapor-liquid, two-phase medium. Under a BEP (Best Efficiency Point) flow rate, bubble cavitation increased along the suction side when decreasing the NPSH. When this bubble cavitation reached the throat, a wedge-like cavity appeared at the pressure side and a steep head breakdown occurred. This breakdown was found to be reasonably predictable by using cavitation CFD.

Keywords
Centrifugal pump, Cavitation breakdown, Pressure measurement, Cavitation CFD, Cavitation modeling

by Yutaka YONEYAMA, Katsuhiro TAKENO, Kikuo SHIMIZU, Tatsuo NAITO, Fumio ITAGAKI, Yoshimitsu YASUHARA, & Mutsuo NAKADA
A sludge recycling and treatment center that makes use of thermophilic methane fermentation from domestic kitchen waste and night soil sludge started operation in Japan in 2000. The characteristics of the raw material (night soil sludge, domestic kitchen waste), the performance of methane fermentation, the effect of recycle flow on the water treatment system and the cogeneration of electric power has been studied by collecting methane fermentation data for two years. During this periods, stable methane fermentation performance was achieved. The highest electrical power generation by methane gas was 2,243 kWh/day. This was equivalent to about 15.3% of the power consumed at the entire sludge treatment plant. Due to the return water flow from the methane fermentation process, the BOD/Kj-N of the activated sludge influent water was lower compared to when there is no recycle flow. Therefore, there was a tendency for the amount of methanol charged into the secondary denitrificatin tank to increase. However, the cost of this consumed methanol was small compared to the total running costs. Results indicate that is possible to implement a full-scale treatment plant that makes practical use of organic waste.

Keywords
Methane fermentation, Full-scale process, Night soil, Septic tank sludge, Household kitchen waste

by Yutaka YONEYAMA, Katsuhiro TAKENO, Kikuo SHIMIZU, Tatsuo NAITO, Fumio ITAGAKI, Yoshimitsu YASUHARA, & Mutsuo NAKADA
A sludge recycling and treatment center that makes use of thermophilic methane fermentation from domestic kitchen waste and night soil sludge started operation in Japan in 2000. The characteristics of the raw material (night soil sludge, domestic kitchen waste), the performance of methane fermentation, the effect of recycle flow on the water treatment system and the cogeneration of electric power has been studied by collecting methane fermentation data for two years. During this periods, stable methane fermentation performance was achieved. The highest electrical power generation by methane gas was 2,243 kWh/day. This was equivalent to about 15.3% of the power consumed at the entire sludge treatment plant. Due to the return water flow from the methane fermentation process, the BOD/Kj-N of the activated sludge influent water was lower compared to when there is no recycle flow. Therefore, there was a tendency for the amount of methanol charged into the secondary denitrificatin tank to increase. However, the cost of this consumed methanol was small compared to the total running costs. Results indicate that is possible to implement a full-scale treatment plant that makes practical use of organic waste.

Keywords
Methane fermentation, Full-scale process, Night soil, Septic tank sludge, Household kitchen waste

by Akiko MIYA, Makiko KARUBE, & Kazuaki SYUTSUBO
A study was made on the biodegradation of petroleum-contaminated soils using weathered crude oil and phenanthrene as hydrocarbon sources. Experiments were conducted to study oil biodegradation characteristics of soil samples and analyses were made on microbial structures by PCR-DGGE in an attempt to identify dominant petroleum biodegrading bacteria. Study results indicated that the combination of an appropriate propagation method and a microbial analysis could enable estimating biostimulation effects of petroleum-contaminated soils within a relatively short time.

Keywords
Contaminated soil, Bioremediation, Molecular biological tools, Microbial structure, PCR, DGGE, Isolation, Petoleum hydrocarbon-contaminated soils, Alkanes

by Teruaki KITAMURA, Yuji WADA, Koichi HAYAKAWA, & Kazuhiro ESAKI
A new total management system, named the e-Human's, has been developed for supporting BPR (Business Process Re-engineering) in environmental engineering business. This system makes use of leading edge IT to enable re-engineering of business processes for large-scale projects, optimization of project management, application of foreign standards, minimization of construction costs, as well as enhancement of proposals.

Keywords
BPR (Business Process Re-Engineering), IT (Information Technology), O & M (Operation & Maintenance), Environmental Engineering Business, PMS (Project Management System), EDMS (Engineering Document Management System), MMS (Material Management System), Web-EDI

by Tetsuro OKOCHI, Shoji MIZUTANI, Seiichi TSUJI, & Kazuhiro ESAKI
EBARA's e-Human's is a total information management system which supports large-scale innovations, such as for document management, project management and external procurement functions, in the IT-infrastructure for environmental engineering business. A shift from mainframe to open server systems is now taking place in this field of business. In 2002, the total number of servers within EBARA for subsystems reached 170, including 5 host systems. This posed serious security and management risk, not to mention high management costs and difficulties in the management of open systems. Progress in IT is making it imperative to achieve co-ownership and active use of information among different EBARA entities and clients, while maintaining adequate security. These factors are becoming indispensable for boosting corporate competitiveness. The following discusses the application of e-Human's to environment engineering business and innovations made in EBARA's IT-infrastructure while solving abovementioned problems.

Keywords
IT : Information Technology, IT-Infrastructure, Mainframe, TCO: Total Cost of Ownership, Identity Management, EIP: Enterprise Information Portal, Database, Server, System, EAI: Enterprise Application Integration

by Eiko TOMINAGA, Kenichi FUJITA, Masanori SAITO, & Takahiro ISOZAKI
The EMMD-Web unit is an IT device for monitoring manhole pump facilities via computer Internet browsers. The following introduces a manhole pump monitoring system which features this EMMD-Web unit. This system enables efficient and thorough monitoring.

Keywords
Manhole pump, Monitoring system, Monitoring device, Low cost, Maintenance, EMMD-Web Unit, Modem, Terminal adaptor, Provider, Radio monitoring system

by Takahisa SEKINO, & Hirofumi NAKAYAMA
A fuel feed pump has been developed for the engine test cell of ANA (All Nippon Airway) at Haneda International Airport. Jet engines are taken apart and inspected periodically to ensure safety. The last process involves test runs of the reassembled jet engines. The developed fuel feed pump optimally feeds the fuel to the jet engine during such test runs, matching the engine type and controlling the flow rate and pressure for particular load conditions. The following outlines this pump and discusses its features, components and control method.

Keywords
Fuel feed pump unit, Jet engine, Pressure control valve, Surge tank, Filter separater, Self priming tank, Ejector, Fuel feed pump, Trial run

by Takeshi ASANO, Shinya HIBINO, & Toshihiro HOSOI
EBARA's tubular turbine (2400 kW) system is being used at Shin-Tawara-Iseki Power Station, located in the Yoshii River Dam in Okayama Prefecture. The new technology featured in this system is a roller-screw-driven runner vane and an electrically-operated runner vane servomotor. The turbine itself is an electrically-operated bulb-type, the first of its kind developed by EBARA. The following outlines this system used in the power station.

Keywords
Small capacity hydraulic turbine, Tubular turbine, Bulb-type turbine, Electrically-operated runner vane servomotor, All electrically-operated bulb-type turbine

by Hidenobu OKAMOTO, & Akira GOTO
A suppression of cavitation in a Francis turbine was attempted using the inverse design method. Blade loading parameters and influences by rake angles were studied. Numerical prediction of the blade-surface static pressure of a conventional runner and that of a runner designed using the inverse design method was done by CFD analysis and the results were compared. The inter-runner static pressure distribution was suppressed based on blade loading parameters. Consequently, the suppression of cavitation was achieved by increasing the minimal inter-blade static pressure. It was found that the inter-runner minimal static pressure was sensitive to the rake angle. Accordingly, blade loading parameters and rake angle control were used to design (using the inverse deign method) a runner which carried high cavitation resistance properties. Such results suggested the possibility that the inverse design method could be an effective tool for designing turbine runners.

Keywords
Inverse design method, Cavitation, Francis turbine, Runner, Blade loading parameters, Rake angle, Static pressure, Suppression, CFD (Computational Fluid Dynamics)

by Yosei KATSU, Toshihiro TANAKA, Asei MIZUOKA, & Masaaki NISHIMOTO
Activated sludge treatment using dynamic filtration was studied by conducting continuous treatment of actual sewage. Dynamic filter modules were equipped in a denitrification process for apartment complex wastewater, as well as in a food wastewater activated sludge process. Favorable filtration and stable nitrogen removal was indicated for the former. As for the latter, a mean flux exceeding 2 m/day and a mean filtrate SS concentration of 10 mg/l were attained by a pilot plant (capacity: 100 m3/day max.). These results suggested the high filtration performance of the dynamic filters, as compared to that of conventional sedimentation ponds.

Keywords
Activated sludge, Solid-liquids separation, Dynamic filtration, Flux, Turbidity, Denitrification

by Toshio HARA, & Masahiro SHIGYOU
Three-dimensional digital data is becoming a standard in the machinery manufacturing industry. EBARA's new 3-D digital image system enables a swift and easy creation of 3-D image models from 2-D drawings and catalog manual data. A mother model is made by converting a mechanical 3-D/CAD model to an engineering 3-D/CAD model. The system's parametric auto generation function then creates a 3-D image model from this mother model. The resulting 3-D image model has various usage, and can be used for reviewing plant layouts, reviewing design factors of pipelines, or for maintenance support of training systems.

Keywords
Three dimensinolcal engineering, Three dimensional model, Three dimensional image model, Parametric data, Design review, Digital engineering, Clay model, Super clay model, Hybrid model, Mother model

by Koji MURAKAMI, & Atushi TAKAHASHI
The pump facility for the Arakawa Drainage Pump Station (planned pumping rate: 19.045 m3/sec. and current pumping rate 8 m3/sec.), under construction since May 2001, has been completed in September 2003. The new pumping facility, constructed underground, was employed as part of an improved floodwater control, i.e. to change the sewage flow from a combined to a separate type. A dual fuel system and vertical gas-turbine engines are used. Fuel gas is treated using fuel gas under routine conditions and kerosene is stored for use as auxiliary fuel, thus improving reliability. A Nitrogen removal system featuring the use of liquefied ammonium is used for reducing NOx in the flue gas.

Keywords
Gas turbine-engine, Fuel gas, Gas compressor, Flue gas De-NOx equipment, Ammonia, Catalyst

by Toshiaki MIYASHITA, Sadayoshi TAKAHASHI, & Junichi ENZAWA
The Kazusa Power Plant, a 100 MW class combined-cycle power generation plant (gas turbine× & steam turbine×1), developed by Ennet Corporatioin (Power producer and supplier) and EBARA for E-Square Co., Ltd. has been operating since April 2003. The steam turbine (Model 2SQNV-9) is a 10-stage, multi-valve, condensing horizontal type while the gas turbines (Model FT8) are an aero-derivative type. This plant follows a DSS (Daily Start Stop) schedule and a stable power supply is being provided for supplementing Ennet Corporation power control.

Keywords
Power producer and supplier, Combined cycle, Gas turbine, Steam turbine, Heat recovery steam generator, Distributed control system, Startup and shut down sequence, 10' stage multi-valve condensing turbine, Aero-derivative

by Wataru SUGIYAMA, Nobuyuki KATO, & Shinobu NAGAYOSHI
EBARA's transverse ventilation system, featuring concentrated exhaust, has been installed in the Higashiyama Tunnel in Nagoya City. This system is an outcome of intensive research on a ventilation system capable of removing both vehicle exhaust gas and smoke which may result in vehicle fire in the tunnel, including supplying fresh air into the tunnel. Air pollution factors had also been sufficiently worked out. EBARA ventilation system includes that installed at the Midoribashi Ventilation Station (for one direction) and the ventilation control equipment for the entire length (for both directions) of the tunnel. The following outlines the system which has been operating smoothly since March 29, 2003.

Keywords
Higashiyama Tunnel, Midoribashi Ventilating Station, Tunnel ventilation, Transverse ventilation system with concentrated exhaust, Variable pitch exhauster, Control system of air flow velocity, Quantity control plate, Electrostatic precipitator, Fire test

by Hiroshi ISHII, Kenji YAMASAKI, & Akira YOKOTA
The Mutsu-Ogawara Wind Farm and Iwaya Wind Park located in Shimokita Peninsula, Aomori Prefecture, constitute Japan's largest-scale wind turbine power generation facilities. EBARA has used it's accumulated knowledge and expertise, as well as leading edge techniques to design and manufacture a total of 60 large-scale wind turbine systems (1500 kW) installed at these two locations. These facilities are expected to become models of future large-scale wind farms in Japan.

Keywords
Wind turbine generator, Mutsu-Ogawara, Iwaya, Wind Farm, Wind Park, Large scale

by Kazunari YOSHIMURA
ISO standards and protocols being implemented worldwide are causing an impact on Japanese waterworks. The Japanese Committee on ISO/TC224 is engaged in advocating matters related to drinking water supply and sewerage services in Japan. Some issues faced in Japan, due to the inactivation in the water demand, reduction in the population, high costs needed to modify existing waterworks facilities, including the privatization of such facilities. The following discusses general matters on international standardization in Japan, including the current status of and trends in TC224 implementation.

Keywords
International standard, International Standard Organization, International Electrotechnnical Commission, World Trade Organization, Technical Barrier to Trade, Technical Committee 224, Performance indicators, International Water Association, Public health, Environmental protection

by Toshihiro OHTANI, Hirotsugu OGI, & Masahiko HIRAO
Changes in ultrasonic attenuation were studied by conducting creep tests using austenitic stainless steel specimens (exposed to a temperature of 973 K and put under various stress). The EMAR (Electromagnetic Acoustic Resonance) method, a contact-less resonancemethod which uses EMAT and by which extra energy loss can be disregarded, was used for the measurement of intrinsic attenuation. Polarized shear waves were applied along the thickness direction of plate specimens to obtain the ultrasonic velocity from the resonance frequency, as well as to obtain the attenuation coefficients from the ring down curve at resonance. Attenuation was found to exhibit greater sensitivity to damage accumulation than velocity. Approaching rupture, attenuation increased ten-fold the initial value, a phenomenon attributed to microstructural changes, especially to dislocation mobility. This result matches that of TEM micrographic observations on dislocation structure of specimens. This method exhibited a potential to be usable for predicting damage and creeping in metals.

Keywords
Creep damage, Electromagnetic acoustic resonance (EMAR), Ultrasonic attenuation, Electromagnetic acoustic transducer (EMAT), Noncontact evaluation, Stainless steel

by Kaori TSUTSUMI, Yukio KEMMOCHI, Akihiro ARIKAWA, & Yuichi FUCHU
Coagulation-precipitation treatment using ferric chloride was carried out to study the isomer-specific correlation between the dioxin isomer concentration in wastewater and the removal efficiency of chemical clarification. The raw water used was wastewater from the wet scrubbing system of a solid waste incinerator. The treated wastewater was fractionated with 1 μm and 0.1 μm filter, and the dioxinconcentration in each fraction was determined. The isomer profiles indicated that 1) dioxin concentration in the "< 0.1 μm" fraction decreased, and 2) dioxin in the "from 0.1 to 1 μm" fraction between temporary increased by the coagulation process. Hence, it become clear that dioxin particle size increases and dioxins can be removed by coagulation-precipitation treatment. The relationship between dioxin isomer concentrations in nontreated water (x) and treated water (y), and flocculant concentration (A) is expressed by the following regression equation: y=2.3×1010×(x/A)+1.8.

Keywords
Dioxins, Wastewater, Iron trap MS/MS, Size distribution, Chemical clarification

by Shigeru KONDO, & Atsushi KANEKO
A new submersible sewage pump (Model DL) has been developed with specifications matching the demand of such pumps for the overseas market. This pump features higher capacity (flow rates) and head versus the conventional DL model. The use of a sweep-back impeller vane enables prevention of fibrous foreign matter from entangling in the leading edge section, as well as an improvement in non-clogging. Hydraulic analysis by the inverse design method allows sufficient free impeller passage to be maintained, thus realizing high efficiency. This pump is a larger scale model in the DL series (diameter: 150-300 & output: 30-45 kW).

Keywords
Submersible sewage pump, Free impeller passage, Non-clogging, Meridional shape, Inverse design, High efficiency, Pump efficiency, Velocity vectors, Capacity, Head

by Junya KAWABATA
A new stainless steel, vertical multi-stage pump series (Model EVM) has been developed for the world market. This type pump is used worldwide for its low cost and minimal area needed for installation. The technologies used in EBARA's VDP (domestic use) and EVM (overseas use) were combined and are featured in this new EVM series. Maintenance is facilitated by use of cartridge mechanical seals in all EVM models. The configuration of the pump is such that makes it compatible with various flange and motor standards. Hydraulic parts, such as the impeller, were designed using the inverse design method. As for larger-scale models, an attempt had been made to upgrade pump performance by use of 3D pressed impellers.

Keywords
Vertical multi-stage pump, Cartridge mechanical seal, Laser welding, Stainless press, Guide vane, Stainless lining, 3D impeller, Thrust bearing

by Takahide KOMATSU, & Satoshi NAKAHARA
A new high-head, packaged booster system equipped with an inverter has been developed for use in high-rise buildings. This system is capable to supply water at a head ranging 80 m -200 m, a range which conventional such systems couldn't achieve. This system also meets the 'standard for effect to water quality' stipulated in the Japanese law on tap water, thus enabling the supply of safe potable water. A backup system allows continued water supply in an event the main system fails.

Keywords
Packaged booster system, High-head, Inverter, Standard of effect to water quality, Backup, Controller, Analog board, Remote control, Estimated constant end pressure control, Fuzzy control

by Junya NISHIMAKI, Koichi OGIWARA, & Takashi YAMANAKA
The Drain Pump Unit is a truck-transportable unit which can include a combination of particular drainage equipment.

Keywords
Drain pump unit, Emergency drain pump truck, Battery railway truck, Engine-driven generator, Lightweight pump, Motor-driven pump

by Hiroshi UDAGAWA, Koichi FURUYA, & Satoshi ITO
EBARA's Tunnel Ventilation System is now being used in Asukayama Tunnel, which runs below Japan Railway's Oji Station and Asukayama Park. This system features effective control over portal leakage by combined ventilation (longitudinal, exhaust type semitraverse & longitudinal). The following outlines this system, including its design factors.

Keywords
Asukayama Tunnel, Central Circular Oji Route, Control of portal leaks, Environmental-impact assessment, Combined ventilation method, Dispersed exhaust port, Model test, Tunnel ventilation

by Toru ABE, Taiji YAMAMOTO, & Keisuke TAKADA
EBARA's Storage-battery Type, Backup-independent, Power Source (Photovoltaic+Small-scale Wind Power) Hybrid Generation System has been installed at Yagiha Lake Village Park, Yamanashi Prefecture. This system generates power from both solar and wind energy and is fit for use in remote areas with no commercial electric power sources. It is also usable as an emergency power backup system during disaster situations. At the park, power from the photovoltaic power source is used to operate a submersible pump which circulates water from a reservoir to the lake by way of an artificial stream. This achieves a natural water purification cycle. Power from the wind turbines (also from the photovoltaic system) is stored, converted into AC 100 V and used as a power source for lights and such in the park. The following outlines this novel, environmental-friendly system.

Keywords
Photovoltaic module, Control panel, Hybrid, Wind power generator, Photovoltaic power generation, Storage battery, Inverter, Independent power source, Display panel

by Satoru INOUE, Hideaki FUEKI, & Yoshiyuki JINBO
EBARA's Fluidized-bed Gasification Ash-Melting Furnace System (capacity: 46.5 t/[dayfurnace]×2 lines) has been installed at the Kiribayashi Clean Center of Minami Shinshyu Wide-area Union. The following are some notable features of this system. Excess heat from the furnaces is recovered by a heat recovery boiler. The steam in this boiler is either used as a heat source within the center or used for power generation (max. 780 kW by steam turbine-generator). The power generated is mainly used within the facility. As for pollution prevention, the dioxin concentration in the system's exhaust gas is kept below the national pollution standard of 0.05 ng- TEQ/m3 (NTP). Metals in the non-combustibles are recovered as recycled resources and slag is effectively used as various construction material.

Keywords
Municipal waste, Gasification ash-melting furnace, Allowable standard, Dioxin concentration, Power generation, Recycling, Slag, Waste gas boiler, Steam turbine generator, Catalytic reaction tower

by Kohei YASUI, Tomoaki OHARA, Nobuya AZUMA
EBARA's Fluidized-bed Gasifier with Ash-Melting Furnace system has been installed at Clean Plaza Chunou Prefecture. The capacity of this system is 56 tons per day×3 furnaces, a total of 168 tons per day. From October 2002 to October 2003, 32 000 tons of waste has been incinerated. The melting of incineration residue and the use of an oxygen generator for boosting the melting is resulting in prolonged life of final disposal sites as well as saving in costs. The exhaust gas from this system satisfies environmental standards and excellent operational feedback is being reported.

Keywords
Gasification melting furnace, Fluidized-bed gasification furnace, Ash-melting furnace, Final disposal site, Residue from landfill, Oxygen generator (PSA oxygen generator), Slag, Fly ash, Interlocking blocks containing slag, Waste heat boiler