Technologies

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Ebara Engineering Review No.189

Development of Seal Dynamics Measurement System for Active Magnetic Bearings

by Masato EGUCHI, Yoshiyuki MARUTA, & Takashi KANEKO

A measurement system had been developed for measuring fluid reaction forces generated on annular pressure seals. This system is applied for active magnetic bearings capable of 5-axis control, with the exception of the rotational direction. This user-friendly system features a compact structural design, as its magnetic bearing is utilized as a bearing, a shaker, and a force detector. Precise determination of stiffness and damping characteristics of annular pressure seals can be made under a non-contact state. Another great feature of this system is that measurement can be done under high pressure and high speed operational conditions. The following gives an overview of this system and introduces results of tests carried out for estimating the reliability factors of components necessary for identifying rotordynamic force coefficients.

Keywords
Active magnetic bearings, Annular pressure seal, Fluid reaction force, Rotor dynamics, Electromagnetic force

A Bench Scale Plant for Supercritical Water Oxidation

by Takashi USUI, Syusaku HAMADA, Hirokazu SATO, Tatsuya NISHIMURA,Roberto Masahiro SERIKAWA, & Hideo SEKINO

A continuous type, bench scale plant for supercritical water oxidation was developed and a combustion test using IPA (Iso-Propyl Alcohol) as the fuel was carried out. The test results indicated that charging IPA into the reactor, set at 26 MPa (internal pressure) and under a temperature of 320°C, led to a fast increase in temperature and made it possible for stable oxidation. The same also indicated that the internal temperature of the reactor was able to be easily controlled by adjusting the amount of IPA charged. It was verified that maintaining the internal temperature at over 500°C resulted in reducing the CO concentration to below 5 ppm, thus establishing that a clean combustion without any NOx generation was enabled. An experimental test was also conducted to study treatment of fly ash slurry under a supercritical condition. Test results here indicated that a high decomposition rate of hazardous organic chlorine compounds was being achieved. A problem! of calcium compound attachment on fly ash was solved by water cooling the supply line. Activated carbon and fly ash were treated simultaneously by superheated steam as compensation for a drop in oxidation due to the water cooling.

Keywords
Supercritical water, Supercritical water oxidation, Iso-propyl alcohol, Fly ash, Dioxins, Reactor, Slurry, Subcritical water, Super-heated steam, Decomposition

Investment Models for Precision Castings Utilizing Rubber Molds

by Katsuhiko SAKAMOTO, & Toshiyuki OGAWA

EBARA has, based on concepts of a plant specializing in the manufacture of hydraulic parts, such as impellers and guide casings, been directly fabricating parts with pump hydraulic configurations using 3D CAD data and RP (Rapid Prototyping) technology. Such parts have been mainly used as investment patterns for investment casting. The authors have recently studied rubber molding techniques in an effort to minimize the lead time and implement large-item, small-scale production for RP-utilizing fabrication processes. RP parts were transcribed to rubber molds (functioning as negative molds) and investment wax patterns, transcribed from the negative molds, were implemented for investment casting. As another attempt, casting ceramic shells were directly transcribed from rubber models and the result was favorable. The studies carried out herein revealed that rubber was deformable during wax extraction and that rubber molds were able to be easily assembled. Thus, it was found unnecessary for the rubber molds to have fine partitions, nor was it found necessary to carry out conventional metal pattern designing.

Keywords
Rapid prototyping technology, Investment casting, Rubber mold, Metallic pattern, Investment model, Hydraulic parts, Short lead time, Large item small scale production, Ceramic shell

Development of New Pencil-scrubbing, Cavitation-jet Cleaning Method

by Kenya ITO, & Mitsuhiko SHIRAKASHI

A new cleaning method for post-CMP has been developed for the semiconductor manufacturing industry. EBARAĠs HP clean pump (PJ pump series) is used for efficiently generating cavitation on the surface of wafers and removing fine particles on depressions. Cleaning is done by pencil scrubbing and a cavitation jet. The use of ultrapure water is minimized by this non-chemical using method, thus enabling high level cleaning at low cost. The following outlines this method and introduces operational data.

Keywords
Post CMP cleaning, Particle, Metal contamination, Cavitation, Scrub cleaning, Pencil sponge scrub cleaning, Electrolyzed D.I. water, Cavitation jet

Oshiwake Drainage Pump Station

by Shuu IMAMURA, Toshinori KAJIUCHI, & Masaki MIYAMOTOI

The Oshiwake Drainage Pumping Station, drainage capacity: 40 m3/sec, was completed in December 1999 along with the Oshiwake Diversion Channel. This pumping station, the largest of its kind in northeastern Japan, and channel were constructed in line with the Construction Ministry's project to prevent floods in the area. Remote monitoring and control of pumping operations, utilizing a 20-inch plasma display screen, is enabled via an optical fiber communication network. The station is space and cost efficient, consequent to a compact design of its high speed pumps. Gas turbine engines are used as prime movers and the gear reducers are air-cooled. Demonstration tests carried out in April 2000 confirmed the superior performance and reliability of this pumping station.

Keywords
Cost reduction, High flow velocity, Gas turbine-engine, Remote-control

A Compressor System Utilizing Hydraulic Energy in a Dam Reservoir - EBARA Hydraulic Compressor Unit -

by Yuta NAGANO, Toshiko SUYAMA, Mitsuharu SUZUKI, Masaru ARAGANE, Koji ICHIKAWA, & Koichi SHIMIZU

EBARA's hydraulic compressor unit was developed for utilizing maintenance discharge water of small and medium-sized dams to produce compressed air for use in aeration and fountain facilities. The hydraulic energy of the discharge water itself is used directly and not for water power generation. This establishes the utilization of clean energy for such use without any operation power cost. A reduction in dam maintenance cost is another advantage of this unit. The following introduces and outlines this energy- and cost-efficient hydraulic compressor unit.

Keywords
Dam reservoir, Discharge water, Hydraulic compressor, Water power generation, Clean energy, Running cost, Water turbine, Compressed air, Aeration, Fountain

An Optical Instrumentation System for Municipal Incineration Plants - In Use at Clean Recycle Center 21, Isesaki City -

by Kazushige KUROSAWA, Toshihisa OKABE, Hajime SASAKI, & Hitoshi USUI

A new optical instrumentation system for municipal incineration plants has been developed. This system features measures against noise and electric surge, reduced control cable installation cost, improved safety and reliability, as well as serial data transmission and self-diagnosis. The outline of this system, installed in Clean Recycle Center 21, Isesaki City, Gunma Prefecture, is given in the following.

Keywords
Optical instrumentation, Dust, Distributed control system, Noise, Data transmission, Lightning surge, Control, Optical, EBARA fuidized bed operating & control system, Isesaki

Stoker Firing System for Municipal Waste Incineration Plants - Utilized by 2 Towns Sanitation Association, Inazawa City -

by Eiji KOBAYASHI, Takashi NARUMI, Hideo OKADA, Takeshi HATTA, Motofumi ARIHARA,Tetsuharu IGUCHI, & Akimitsu WATANABE

EBARA's stoker firing system for municipal waste incineration plants, utilized by 2 Towns Sanitation Association of Inazawa City, is equipped with a steam turbine power generation unit. Its main EBARA's co-combustion power plant, installed at Honsha Mill, Daishowa Paper Manufacturing Co., Ltd., features the co-combustion of effluent paper sludge (PS) from the mill, along with shredded waste tires and coal, to generate electric power. This plant is the largest of its kind in Japan, insofar as combustion paper sludge is concerned, and features the largest fluidized-bed incinerator made by EBARA. An internally circulating, fluidized-bed boiler (ICBF) is also featured, making it possible for a stable recovery of high temperature, high pressure steam for the power generation. The concentration of hazardous materials, especially dioxins, in the exhaust gas sufficiently meet the pollution control standards. Full power generation by waste combustion is enabled.

Keywords
Paper sludge, Waste tire, Fluidized-bed boiler, Power plant, Coal, Industrial waste, Dioxin, High temperature high pressure steam, Thermal recycle components comprise 3 incinerators (capacity: 60t/24hours) and a bulky waste crushing/shredding facility (capacity: 50t/day). Dioxin emission is sufficiently controlled to below 0.1ng·TEQ/ m3 (NTP) by blowing activated carbon into the flue gas and utilizing a low temperature bag filter. Excess heat from the incinerators is recovered and used for power generation.

Keywords
Stoker, Dioxin, Remaining, Generation of electric power equipment

Paper Sludge and Waste Tire Co - combustion Power Plant - Honsha Mill of Daishowa Paper Manufacturing Co., Ltd. -

by Keisuke TSUKAMOTO, Hideyuki SAKAMOTO, Toshiyuki KAWABATA, Masaaki IIO, Eiji NAKAYAMA,Masahiko KONNO, & Naoaki MAEDA