Ebara Engineering Review

by Sakae KOSANDA, Hirotoshi HINUMA, & Ryosuke HATA
A novel high-rate sedimentation process has been developed for directly treating combined sewer overflows (CSOs). This was done using a test facility at an actual wastewater treatment plant in Tokyo. Pilot test results, carried out 13 times, from December 2002 to July 2003 in wet weather, suggested that the process was suitable for treatment of CSOs. The performance of the process was favorable at 50 m3/(m2·h) up to 880 mg/L influent TSS, removing between 78% and 91% of TSS at loading and between 64% and 85% of BOD5 also at loading.The pilot testing clarified that a decrease in the influent alkalinity due to rain water caused a drop in the pH after FeCl3 addition and thus improved coagulation, with a significant decrease in the effluent TSS. Mixing, coagulation and flocculation were carried out in a baffling type mixing tank to enable uniform mixing without any short-passes. Coagulation conditions in this mixing method were evaluated and results clarified that rapid mixing was required momentarily after each addition of FeCl3 and polymer, i.e. to diffuse these additives into the influent.

Keywords
Combined sewer system, Stormwater, Coagulation-sedimentation process, Solid-liquid separator, Baffling mixing, CSOs (Combined Sewer Overflows), Flocculation, Diffusion, Alkalinity, SS

by Akira FUKUDA, Hirokuni HIYAMA, Kazuto HIROKAWA, Manabu TSUJIMURA, & Tetsuo FUKUDA
The impact of wafer edge roll-off on CMP performance was studied using FEM (Finite Element Method) analysis. It was found that the edge roll-off influenced the removal rate distribution at the wafer edge of both stacked and solo pads. This influence was up to 4 mm from the edge for stacked pads and up to 10 mm from the same for solo pads. The surface pressure in the vicinity of the edge, for cases where the ROA (Roll-Off Amount) was 1.27μm, was about 30% greater than that at the wafer center for stacked pads and about 23% greater than the same for solo pads. The relationship between the retainer ring pressure and allowable ROA was also studied.

Keywords
Wafer edge roll-off, CMP, FEM analysis, Removal rate, ROA, Stacked pad, Solo pad, Surface pressure

by Masao MATSUMURA
This report outlines EBARA's pumps for handling LNG, some history and trends, and includes an introduction of a newly developed expander turbine generator.

Keywords
Submerged motor pump, Expander turbine generator, Natural gas, Liquefaction plant, Carrier, Receiving terminal, Thrust load, Ball bearing, Self-balance, Clearance

by Fuyuki OHGAKI
A low-cost and compact underground vacuum station has been developed for use in vacuum sewerage systems. The underground vacuum station uses vacuum pump units capable of reciprocal rotation. Contaminated water becomes discharged by injecting air into the collection tank, thus making it unnecessary to use discharge pumps, such as those equipped in conventional vacuum collection stations. The compactness of the vacuum pumps, which are placed inside small units for enabling easy maintenance, save considerable space and the collection tank can be set underground and accessed by a manhole. Installation is thus low-cost with no need to construct a structure for the vacuum station.

Keywords
Underground vacuum station, Vacuum sewerage system, Vacuum pump, Vacuum pump unit, Collection tank unit, Discharge pump, Check valve, Deodorizer, Motorized shut valve, Gravity system

by Hideji ISOBE, Hiroshi YAMASHITA, & Toshihiro SASAGAWA
Snow Lasta, a pump controller for thawing snow, effectively thaws snow on road surfaces making use of pumped up groundwater. Its operation thus has relatively small effect by wind. The Snow Lasta's control panel, equipped with a microcomputer, features a design which enables easy groundwater pumping and pump operation control. The development and production of this product was concerted by EBARA, a sensor manufacturer and a control panel manufacturer. This product features technical know-how accumulated through years of experience in the field. Further studies are being made to enhance this product to meet current and future market demands, especially in terms of environmentally feasible aspects, such as the minimization of water and power consumption.

Keywords
System for thawing snow, Control panel for thawing snow, Snow sensor, Snowflake detection, Snow-fall pulse, Snow temperature detector, Current sensor, Digital indication, Forced backup, Saving water

by Soichi ISOBE, Takao MITSUKURA, & Tadakazu SONE
The newly developed F-REX300SⅡ is an add-on to the F-REX series CMP (Chemical Mechanical Polishing) systems. It features enhanced performance, functions, operability and maintenance capability, thus satisfying the current demand in the semiconductor manufacturing market. This high throughput system comprises a EFEM (Equipment Front-End Module) unit with 4-FOUPs capability, a polishing unit with four polishing tables and a cleaner unit with three cleaning modules and one drying module. Also featured are highly functional transporters in the polishing and the cleaner units, minimized wafer defect during in transportations.

Keywords
Chemical Mechanical Polishing, Increase in wafer dia., Throughput, Semiconductor production process, Front-Opening Unified Pod, Swing transporter, Cleaner linear transporter, Robot, Cleaner unit, Top ring

by Naoaki KATAOKA, Lingyun HAO, Akiko MIYA, Kenichi ISHIDA, Norio YAMADA, & Takayuki SUZUKI
The performance of a methane fermentation process, which included a lipase pretreatment system for catalyzing the breakdown of oils and fats, was studied through batch and continuous experiments. The objects for treatment study were bean-curd-processing wastewater and frying oil containing wastewater. Batch experiment results indicated that lipase pretreatment effectively catalyzed 96% of triglyceride in the oil and fat containing wastewater, breaking it down into fatty acids, alcohol and gas. The methane gas conversion ratio was 80%. As for the continuous experiments, where thermophilic methanogenic treatment was applied on lipase pretreated oil and fat containing wastewater, the experiment results indicated a CODCr removal of 72% and a methane gas conversion of 61% (as CODCr). These study results suggested that combining lipase pretreatment with thermophilic methanogenic treatment was effective for digesting oil and fat containing wastewater.

Keywords
Oils and fats, Bean-curd-processing wastewater, Frying-oil, Mesophilic methane fermentation, Thermophilic methane fermentation, Methane gas, Pretreatment, Lipase, Long-chain fatty acid, Triglyceride

by Kaoru YAGI, & Yuko KOYABU
A new F3100 series, inverter-equipped packaged booster system for use in high-rise buildings has been developed. This system, equipped with EBARA's new EVML pump, is capable of supplying water to 80 - 250 m. It meets the standard of effect to water quality stipulated by Japanese's law on waterworks, and the water it supplies is perfectly safe to drink. A backup function is included to continue the water supply when a pump failure occurs.

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

by Kazutaka OKUDA
A packaged booster system, used with a submersible deep-well pump for drawing water from deep wells, has been newly added to EBARA's F3100 Series which features the use of inverters and constant end-pressure control. This system meets the current requirements such as energy saving, minimization of construction, minimization of installation space.

Keywords
Deep well, Inverter, Submersible pump, Packaged booster system, Estimated constant end pressure control, Stainless steel, Energy saving

by Eiji TSUTSUI
The Model DWO stainless steel volute pump is designed for use under relatively high flow rates and low heads, and capable of operation even when there are foreign substances in the pumped water. Its main parts are made of stainless steel and it is equipped with a mechanical seal protector as a measure against the inflow of foreign substances, thus making it a semi-open type. The following outlines this pump and introduces its features.

Keywords
Stainless steel press, Rust, Foreign substance, Mechanical seal protection, Washing machine, Volute pump, Spring, Compact, Light weight

by Masahito KAWAI, & Kazutaka OKUDA
EBARA's newly developed Model FMFD multi-stage fire fighting pump is a directly-driven type, featuring integrated pump and motor axes. This design satisfies the current demand for space-saving and compactness. Its discharge capacity is 900 L/min which considerably exceeds that of conventional same-scale fire fighting pumps. Plans are underway for developing larger bore series of this model.

Keywords
Fire fighting pump, Fire fighting low, Fire fighting facility, Multi-stage pump, Direct driven motor pump

by Sota NAKAGAWA, Yuji SASAKI, Makoto KASHIWAGI, Koichi HAYAKAWA, Keiji MAISHIGI, & Masaji AKAHORI
A novel fluorine recycling system, comprising an FTR (Fluoride treatment for Triple R - Reduce, Reuse and Recycle) electro-dialysis equipment has been developed. Development targets were centered on reduction of environmental impact by fluoride containing wastewater and realizing a fluorite recovery process on equipment capable of degrading-concentrating fluorine for easy recovery and reuse. The FTR electro-dialysis equipment features exclusively developed non-woven fabric for ion exchange, whose use has made it possible to treat highly corrosive hydrofluoric acid under unprecedented high membrane permeability, thus achieving a high separation-concentration performance. The fluorite recovery equipment produces crystallized CaF2, adequate for use as a recycled resource for hydrofluoric acid production plants. This system is expected to greatly contribute to environmental protection and resource availability for semiconductor and electronic part manufacturers.

Keywords
Fluoride acid, Fluorspar, Wastewater, Environmental impact, Recycling, Electro-dialysis, Ion exchange non-woven fabric, Crystallization, Semiconductor, PRTR (Pollutant Release and Transfer Registers)

by Taku MIYAGI, & Koji ABE
Two large-scale, vertical volute pumps (discharge bore: 1500 mm and total head: 70 m) have been installed in a deep underground drainage pump station located about 80 m underground. These pumps feature space-conservation which was achieved by eliminating the use of check valves on the pump discharge side. These pumps are used to drain floodwater stored underground into Tokyo Bay, thus preventing floods.

Keywords
Drainage pump station, Vertical volute pump, Pump dry operation, Without check valves, Speed control, Deep underground, Reversal prevention

by Kenichi SUGIYAMA, Satoshi KAWAMURA, Hiroshi NAGASAKA, Toshiyuki OGAWA, Takayuki NARITA, & Yasuo ASANO
TDeep concern is being directed at the erosion-resistance of pump impellers being operated in Yellow River pumping stations in China. The type of erosion these impellers face are slurry erosion induced by sand impingement and cavitation erosion. As a measure, EBARA has developed methods of predicting volume-loss by slurry erosion. The prediction method features the use of factors such as impingement angle velocity, frequency and impingement particle distribution. As for erosion-resistance, self-flexing alloy coatings have been developed. The following introduces these and discusses test results.

Keywords
Slurry erosion, Cavitation erosion, Thermal spraying, Pump, Impeller, Coating, Anti-erosion materials, Prediction of volume loss, Yellow River, Self-flexing alloy

by Naoyuki INOUE, Takao TAKEUCHI, Atsushi KANEKO, Tomoyuki UCHIMURA, Kiichi IRIE, & Hiroyoshi WATANABE
A practical power generation unit, made using study results on working fluids and expansion turbines, was tested in the course of developing a simple and compact, waste-heat-driven power generator. A comparative study was made on the characteristics of various working fluids in a low-temperature heat source cycle (evaporation: 77°C& Condensation: 42°C). Study results indicated that TFE, R123, and R245fa were working fluids suitable for the intended power generation cycle. Among these TFE was selected out and a radial turbine was designed and manufactured as a turbine for use with TFE. A power generation experimental apparatus, driven by hot water as the heat source and cooling water as the cooling source, was put together and operated. The generated power was transmitted to the electric utility system via an AC converter. Power generation cycle and expansion turbine characteristics were clarified through tests using the actual power generation unit.

Keywords
Power generator, Waste heat, Ranking cycle, Working fluid, Expander, Radial turbine

by Kenji TERAO, Tsutomu KARIMATA, & Hiroshi SOBUKAWA
EBARA's EBeye300, a semi-conductor wafer inspection system, applying projection electron microscope technology, is currently undergoing development. A previous report on the same system discussed that the inspection speed of this system could in principle be 3 - 6 times faster than that of a conventional electron beam inspection system (applying scanning electron microscope technology). An actual EBeye300 system based on this design concept was made and used in inspection performance tests on test wafers. The following introduces the geometry of this system, the performance of each component, and performance test results.

Keywords
Defect, Inspection, Semiconductor, Electron beam, Projection, Scanning electron microscope, Pixel size, Yield management, Voltage contrast

by Masaaki OSATO, Tadakazu NISHIKAWA, & Yoichi MORI
The Global Warming effect is a problem of worldwide concern and at the Third Conference of the Parties (COP3) to the Framework Convention on Climatic Change (FCCC), held in Kyoto, Japan on December 1997, determination was reached that there was a need to reduce the emission of perfluoro compounds during microchip manufacturing. This so-called Kyoto Protocol started off national and regional engagement towards perfluoro compounds abatement on a worldwide scale. Consequently, fired thermal type and electrical thermal type (including that which uses catalysts) perfluoro compounds containing exhaust gas treatment systems started being used. However, this has led to an increase in the load on wastewater treatment systems of semi-conductor manufacturing plants, as fluorides produced after decomposition are treated using water in such treatment systems. The following introduces a solution to this, a newly developed dry chemical-reaction type exhaust gas treatment system which is capable of high-efficiency perfluoro compound decomposition and which adsorbs decomposed fluorides into adsorbants without releasing them into the wastewater flow.

Keywords
Perfluoro compounds, Global warming effect gas, Chemical reaction type for PFCs, Hydrogen fluoride, Electrical thermal type with catalyst, Fired thermal type, Electrical thermal type, Chemical reaction and physical adsorption type, Wet treatment type, Calcium fluoride

by Kazuyuki SUZUKI
EBARA CORPORATION is now actively engaged in intellectual property related activities to meet current domestic and international intellectual property trends. The following introduces our corporate concepts regarding intellectual property, as well as some chronological factors and results of intellectual property related activities. We feel that enthusiastic engagement in such activities is the key to the sustenance of a 21st Century engineering corporation.

Keywords
Intellectual property, Recent trends, IP strategy, IP organization of EBARA, Action program 2005, Workflow system, Patent map, Skill up

by Electromagnetic Acoustic Resonance
by Toshihiro OHTANI, Hirotsugu OGI, & Masahiko HIRAO
The microstructural evolution of Waspaloy, a nickel-based super-alloy, was studied using EMAR (Electromagnetic Acoustic Resonance). The Waspaloy was subjected to tensile creep at 1073 K and shear-wave attenuation and velocity was monitored by EMAR. Taken into account was the observation that contact-less transduction based on the Lorenz force mechanism was the key to establishing the monitoring of microstructural changes in the bulk of highly sensitive metals. A clear relationship was found between attenuation and life fraction. In the interval, 35% to 40% of the creep life, attenuation reached a peak, independent of applying stress. This novel phenomenon was interpreted as being a drastic change in dislocation mobility and the coarsening of γ'- precipitates. This was supported by SEM and TEM observations. During the occurrence of this phenomenon, dense dislocations started to tangle to γ'- precipitates, with the coarsening and condensation of γ'- precipitates becoming saturated. It was thus established that it was possible to use this EMAR assessment method to assess the progress of damage in metals and predict their remaining creep life.

Keywords
Creep damage, Ni-base superalloy, EMAT, Ultrasonic attenuation, Non-contact evaluation, Dislocation

by Naoyuki INOUE, Kiichi IRIE, & Yukihiro FUKUSUMI
Theoretical analysis was conducted on various absorption cycles, assuming reversible cycles, in an effort to improve the performance of a boosted temperature type absorption heat pump. Comparison was made using the Carnot cycle to estimate the COP, temperature boost and maximum performance. A simulation model assuming the usage of H2O-LiBr as the working fluid was developed to study the performance. It was found that a direct flow of heat source hot water from a generator to an evaporator was favorable for high performance.

Keywords
Absorption, Heat pump, Absorption cycle, Temperature boost, Steam generation

by Yutaka MORI, Kazufumi TATEISHI, Kazunori YOSHIDA, & Koichi WADA
A novel backup power generation system for traffic signals, featuring the use of a hydrogen-based polymer electrolyte fuel cell, has been developed. A performance test is now underway using a prototype for traffic signals at an actual intersection. This highly reliable, safe and compact system's operational features are quick startup, favorable performance under load, no performance drop due to vehicular exhaust gas constituents, operability under high and low temperature (including that under direct sunlight exposure). The following discusses this systemOs development factors and performance test results.

Keywords
Fuel cell, Polymer electrolyte fuel cell, Backup power generation, Traffic signal, Light emitting diode tight lamp, Power failure, Hydrogen cylinder

by Kikuo NISHIYAMA
A high discharge pressure de-scaling pump, capable of being operated at a discharge pressure of 50 MPa and coupled with a rapid variable-speed coupling, has been developed. Fatigue-causing high amplitude and high cycle stress applying on the pump has been coped with by an elliptically shaped nozzle opening section which reduces stress concentration in this section.

Keywords
De-scaling pump, Barrel casing, Thick-wall vessel, Nozzle, Fatigue, Meridional stress, Hoop stress, Stress concentration, Throttle bush, Hard chromium plating

by Toshiaki KIKUIRI
A total of 8 EBARA circulating water pumps have been installed at Jiaxing Power Plant, Zhejiang Province, China. These pumps feature an elongated total length to cope with high differential tides. Adjustable vane angle pumps are also used to optimize plant operation. Special foreign-made actuators are used for the vane angle control units, Cathodic protection is applied for corrosion resistance. The following outlines these pumps.

Keywords
Circulating water pump, Adjustable vane angle, Vane angle control, Anti-corrosion device, Cathodic protection, High differential tide, Actuator, Distributing valve, Self-potential, Condenser

by Naobumi IKEDA, Mitsutoshi HAGINO, Takao MIYAMOTO, & Daisuke MIKAMI
A total of six large-diameter, conical plug valves have been shipped to Chicago, U.S.A. to be used for flood control in Chicago's Tunnel and Reservoir Plan. Two of these valves were designed for use under high flow rates (45 m/sec.), at 30 minute opening and closing time, and to withstand occurrences of erosion, noise and vibration due to cavitations following opening/closing. As a measure against erosion, the plug body and plug were made from stainless steel plates and overlays. Compressed air injection ports have been installed to lessen cavitation and a large-capacity/high-lift-capable operator has been applied for coping with high torques. Lubricant-injection type bearings have been installed to enable lubrication. A water resistant, proximity switch system is also implemented for cylinder location detection.

Keywords
Conical plug valve, Mechanism for open and close, High velocity, Cavitation, Stainless steal overlay, Proximity switch, Dynamic torque, Lubrication system, Shut-off torque, Stress analysis by computer