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Ebara Engineering Review No.202

Ultrasonic Attenuation and Micro-structural Changes in Crept Stainless Steel

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.

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

An Isomer-Specific Correlation between Dioxin Isomer Concentration in Wastewater and Removal Efficiency of Chemical Clarification

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.

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

A New Submersible Sewage Pump for the Overseas Market

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).

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

New Stainless-steel Vertical Multi-stage Pump Series


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.

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

High-head Packaged Booster System (Model F3100)

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.

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

Drain Pump Unit

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.

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

Tunnel Ventilation System

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.

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

Storage-battery Type, Backup-independent, Power Source (Photovoltaic+Small-scale Wind Power) - Hybrid Generation System -

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.

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

Fluidized-bed Gasification Ash-Melting Furnace System - Installed at the Kiribayashi Clean Center of Minami Shinshu Wide-area Union -

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.

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

Fluidized-bed Gasifier with Ash-Melting Furnace System - Clean Plaza Chunou -

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.

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