Ebara Engineering Review

by Yutaka YONEYAMA, Shigemi OKADA, Naohide MATSUMOTO, Ayako IGARASHI, & Akihiro NAKAMURA
In order to establish the feasibility of methane fermentation for treating low organic concentration wastewater, a pilot-scale UASB reactor was operated under an unheated condition over 631 days by seeding mesophilic sewage digested sludge and by feeding with a municipal wastewater. The pilot-scale UASB reactor had a treatment capacity of 50 m3/d, an effective capacity of 20.2 m3 and a net depth of 5 m. The result obtained from a continuous experiment indicated a stable treatment, i.e. , between 397-631 days after the startup. The mean values obtained during this time indicated a biogas generation of 2.4 m3/d, methane gas composition of 70.5%, CODCr removal of 63.8% at water temperature of 23.8℃, CODCr volumetric load of 0.99 kg-CODCr / (m3·d), and CODCr sludge load of 0.12 kg-CODCr /(kg-MLVSS·d).

Keywords
UASB, Unheated condition, Municipal wastewater, Sewage, HRT (Hydraulic Retention Time), CODCr (Chemical Oxygen Demand), Methane, Biogas production rate, Granule

by So KUROIWA, Shoji ITOH, & Masaki WATANABE
This newly developed pump, equipped with an all-in-one controller and PM motor, realizes a Max. 50% plus saving in energy consumption as compared to that of an equivalent conventional pump made by Ebara. Features which make this possible are an upgrade in pump performance by optimized rotational speed control and flow analysis by computational fluid dynamics. This pump model has been introduced into the market in May 2010.

Keywords
Energy saving, Satndard pump, High efficiency, Pump controller, Permanent magnet synchronous motor, High speed, Hydro-design, Noise reduction, Cooling, Maintenance-free

by Kiyoyuki SAKURAI, Tomoyuki SONE, Takehiro OKA, & Junichi ICHIKAWA
A next-generation stoker type incineration plant, the second of its kind Ebara, has been constructed and handed over to the Kariya-Chiryu Environment Association. Development targets included minimized impact on the environment and a visual blending with the landscape. This plant is capable of not only advanced treatment of flue gas but also production of reusable slag by melting incineration ash and fly ash. Another feature is the effective use of incinerator heat to generate electricity which is used in the plant and in other facilities. Moreover, wastewater is treated by a closed system, thus preventing any contamination outside the plant. The previous administration building had been modified for this plant so there was no need to construct a new building. A greening wall had been erected for visual betterment of the landscape. In this way not only the betterment of incineration/treatment performances but also of environmental and landscape factors had been achieved.

Keywords
Next generation stoker technology, Incineration plant, Exhaust gas recirculation, Power plant, Slag, Closed cycle system, Heat supply, Dioxins, Greening wall, Reuse

by Kazuaki WATANABE, Daisuke SAKU, & Katsutoshi NARUSE
A novel fluidized-bed gasification and slagging combustion plant has been successfully installed at Ecotopia Ikehara, run by the Kurahama Sanitary Facilities Association, Okinawa. This plant has a capacity of 103 t/d×3 lines (total of 309 t/d) and furnace flue gas is effectively used in a waste heat recovery boiler which generates a max. of 6000 kW via a steam turbine generator. Dioxins in fly ash is kept below 0.25 ng-TEQ/g, without the use of fly ash dechlorination process, significantly lower than the national standard which is 3 ng-TEQ/g. Slag generated at this plant sufficiently meets 2 Japan Industrial Standards stipulations, namely JIS A 5032:2006 (slag material for road construction) and JIS A 5031:2006 (slag aggregate for concrete). Test results are showing favorable steam flow controllability and expectations are great for this plant's use not only as a waste treatment system, but also as a PPS (Power Producer and Supplier).

Keywords
Fluidized-bed, Gasification, Ash melting, Slag, Fly ash, Dioxins, Power generation, Japanese Industrial Standard, Slag aggregete quality, Steam flow contorollability

by Naoaki KATAOKA
In anaerobic biotreatment organic matter becomes degraded into methane and carbon gas by catabolization of anaerobic bacteria propagating in an oxygen-less/anaerobic environment. This treatment method had started to be applied in Europe between the end of the 19th Century and the beginning of the 20th Century. In the 1950s heating and mechanical agitation techniques were developed for this method. In Japan, the use of anaerobic digestion for reducing and stabilizing sludge in sewage sludge and night soil treatment became widespread around this time. In the 1980s high-load anaerobic biotreatment featuring microbial immobilization was developed and its use became widespread mainly for treating industrial wastewater. At present, focal attention is being directed at anaerobic biotreatment as a source of unused energy for achieving a low-carbon social and economic structure, by producing biomass from domestic waste, food processing refuse, sludge and other such refuse.

Keywords
Anaerobic treatment, Anaerobic digestion, Methane fermentation, Biomass, Methane, Digester, Anaerobic bacteria, Microbial immobilization, UASB, Sludge

by Chikara MAKINO, Junya KAWABATA, & Shunichi AIYOSHIZAWA
An internal cooling system for sewage/wastewater pumps has been developed. The system assures safe operation of the motor even when the pump is not submerged. The system also makes it possible to prevent overheating without using pumped liquid which may contain various foreign matters. In the developed system, a newly designed impeller is located between two mechanical seals, and circulates the coolant through a newly designed passage to the cooling jacket around the motor. Thus, heat generated by the motor is transferred to the coolant and effectively dissipated to the pumped liquid via a heat exchanger.

Keywords
Internal cooling system, Sewage/wastewater pumps, Duplex mechanical seals, Coolant, Heat exchanger, Heat transfer coefficient, Thermal conductivity, Winding temperature rise

by Shohei OKAGA, Koji SUDA, & Satoru KAWASAKI
Japan's largest-scale submerged type membrane filtration system (filtration capacity: 30000 m3/d) has been installed in the existing sedimentation tank of Sano Water Treatment Plant, Hyogo Prefecture. This unprecedented changeover from rapid sand filtration to membrane filtration was accomplished with no stop in water treatment. This allowed a saving in construction cost with no generation of construction debris. Furthermore, the 2.3 m difference in water levels between the sedimentation and filtration tanks allow a natural downward flow (gravity filtration), making it unnecessary to use electric power to transmit the water from one tank to the other. This is achieving significant energy-saving in the filtration process.

Keywords
Using existing sedimentation, Submerged type, Membrane filtration system, Height difference for gravity filtration, L-cube, In desiccated keeping, Energy-saving, Sano Water Treatment Plant, Hollow fiber membrane, Hydrophilic PE

by Masayoshi KITAGAWA
Aerobic bio-treatment constitutes as the mainstay for treating wastewater containing organic pollutants. It is also considered as an important method for removing eutrophication causing elements such as nitrogen and phosphorus. The following outlines characteristics and discusses chronological data regarding development in aerobic bio-treatment technology. Also discussed is the combined use of both anaerobic and aerobic treatment, ammonium oxidation, as well as MBR (Membrane Bio Reactor) technology. Progress in these are looked forward to from the viewpoint of energy conservation, reduction in the amount of generated sludge, and the realization of safe and sanitary wastewater treatment.

Keywords
Biological treatment, Aerobic treatment, Anaerobic treatment, Activated sludge process, Biofilm process, Bulking control, Phosphorus removal and denitrification, Aerobic filtration, Moving-bed biofilm reactor, Anaerobic ammonium oxidation

by Kazuaki SHIMAMURA, Tateki KUROSAWA, & Shojiro WATANABE
A novel phosphorus recovery system, which enables an effective reuse of recovered phosphorus, has been developed for use in sewage treatment. This system constitutes 5 processes, each matching specific sewage characteristics (sewage constituents, concentration, flow rate, etc.). Verification tests carried out using 2 processes which make use of the crystallization effect of MAP (Magnesium Ammonium Phosphate) revealed a phosphorus recovery exceeding 90%. The practicality of these processes can be established from the fact that the recovered phosphorus can be reused as fertilizer. The other 3 processes which make use of the crystallization effect of HAP (HydroxyAPatite) were found to significantly reduce the phosphorus concentration (down to a few milligrams). A study is underway on using the recovered HAP as a substitute for phosphorus ore. All in all, the 5 processes revealed that they effectively contributed for prevention of water contamination, as well as for resource recovery.

Keywords
Phosphorus recovery, Crystallization, Magnesium ammonium phosphate, Hydroxyl apatite, Sewage, Fluidized bed, Fixed bed, Complete mixing, Scale, Anaerobic digestion sludge

by Yasutaka KONISHI, Kazuhiro KANEDA, & Sachiko MIYAUCHI
A novel booster pump system has been developed for high-rise buildings. This system, approved by the Bureau of Waterworks, Tokyo Metropolitan Government, features easy maintenance and a suppression effect for booster pressure fluctuation. Communicative linkage between 2 differently located booster units works effectively to optimally control pumping to different floors.

Keywords
Serially cascaded type, Direct connecting booster pump system, Communication system, Booster pump, Communication panel, Pressure fluctuation, High-rise building, Booster pump system

by Kazuma ITO, & Katsuaki USUI
An energy-saving and small-footprint dry vacuum pump has been developed to meet the demand in semiconductor and liquid crystal panel manufacturing plants. Such demand includes saving in utility (power, cooling water and nitrogen consumption) costs as well as space-conservation (small-footprint). This pump series features considerable saving in utility costs by compression power reduction and motor efficiency enhancement. A small footprint feature has also been achieved by making the pump compact and improving the instrumentation layout.

Keywords
Dry vacuum pump, Vacuum, Energy-saving, Small-footprint, Semiconductor, Liquid crystal panel

by Hideo OSATO, & Yoshihiro KASAHARA
Ebara's concern over environmental measures, in particular against global warming, has led to our development of a novel power-saving dry vacuum pump series for the semiconductor manufacturing industry. As this series enables an 83% saving in energy consumption, it is expected to replace conventional models used in this industry. Enthusiastic promotion for this product is currently underway.

Keywords
Greenhouse effect gas, Semiconductor, Manufacturing equipment, Dry vacuum pump, Energy saving, Replacement proposal

by Toshiyuki OGAWA, & Satoshi INOUE
A new plant for manufacturing large-scale and high pressure custom-made pumps has started off in Futtsu City, Chiba Prefecture. This plant has replaced Haneda Plant as the production hub of Ebara's fluid machinery and systems. The main targets in its planning stage had been to enable manufacturing of high-value added and competitive products, as well as reducing running cost and lead-time. These have now become reality in this plant (overall area of 100000 m2) which had been swiftly completed in almost 2 years. Much is looked forward to this innovative plant which carries the legacy of Ebara's expertise in the pump industry.

Keywords
Futtsu industrial site, Outline of construction and structures, New factory, Large-scale and high pressure custom-made pumps, Improvement in productivity, Large-scale manufacturing facilities, Performance test shop, Partership with regional communities, Futtsu district

by Hideki KANNO, Shigeru YOSHIKAWA, Naoyuki INOUE, & Yoshiro FUKASAKU
CO₂ for CCS (Carbon dioxide Capture and Storage) is at about atmospheric pressure when recovered and needs to be pressurized by compressor, taking into account underground pressure and pressure resistance in the line of passage. An investigation done by simulation revealed that an optimally energy saving operation can be done by compressing CO₂ to 5.0 - 5.5 MPa and condensing it, furthermore pressurizing the CO₂ by an injection pump. The following outlines the turbomachinery used for this process, namely a refrigerating machine for supplying cooling water for CO₂ condensation, and discusses the performance of a large-scale CO₂ gas compressor, as well as of an injection pump for CO₂ pressurization.

Keywords
CCS, Compressor, Refrigerator, Pump, Liquefaction, p-h diagram, Specific enthalpy, Acid gas, Super critical, Power saving

by Akihito TODA
Ethylene plants are recently becoming large sized and their mainstay output 1 million tons annually. Elliott Ebara's capability to manufacture both compressors and steam turbines is meeting high capacity needs for the ethylene market. The following introduces and discusses trends in our next-generation compressors and steam turbines currently being developed.

Keywords
Ethylene, High capacity, High temperature, High pressure, Double shell, Casing, Diaphragm, Rotating bucket, Governor valve, Mechanical drive

by Kazumi OHKANDA
A fire-fighting pump unit, integrated with an auxiliary tank, has been developed for sprinkler systems of social welfare facilities. This pump unit (Model FSDFS) features compactness, achieved by positioning the pump under the auxiliary tank, and outdoor applicability, achieved by equipping an outdoor cover. Four types of pumps can be used with 3 different sized FRP auxiliary tanks, namely with a capacity of 1.0 m3, 1.5 m3 and 4.0 m3, matching specific discharge rates. The unit can be started up automatically by a diaphragm type small-sized pressure tank and pressure switch. It can also be started up manually by a remote switch. The unit's main components constitute many proven conventional ones, and include a Model FSD single-side suction centrifugal pump, a Model EPM2 control panel, and an FA2-25 flow meter.

Keywords
Fire fighting pump, Social welfare facilities, Fire fighting low, Sprinkler, Auxiliary tank, Centrifugal pump, Direct driven motor pump, Outdoor installation

by Teruyasu OKAMOTO, Kyoji HASHIMOTO, Hirokazu KAJIWARA, & Motohiro KOBAYASHI
Japan's largest biomass-burning power plant has been operating under a stable condition for over 1 year. EBARA has been involved in the engineering, procurement and construction of this plant; following the commissioning test, we are also involved in the operation and maintenance. The ICFB (Internally Circulating Fluidized-bed Boiler) used in this plant, while featuring conventional specifications, uses biomass as fuel. Its structure is made more simple than conventional boilers at incineration plants. That and a low air ratio operation is achieving high efficiency and low running cost. Three types of biomass fuel is used at the Gonoike Biomass Power Plant, namely tree bark, saw dust and planer dust. A total of 3 fuel supply sources enable a backup operation in case one source fails or stops. Following the commissioning. The ICFB has operated for 350 days during a period of 1 year.

Keywords
Fluidized-bed boiler, Biomass, Power plant, Engineering, Procurement, Construction, Operation, Maintenance, Dioxins, Bark, Saw dust, Planer dust

by Yuichi IIDA, Takeshi MIYATAKE, Kenji SUGAWARA, & Yuichi NAKAMURA
A resource and energy conserving, high-efficiency biomass power plant has been delivered to the Tochigi Factory of Sumitomo Osaka Cement Co., Ltd. The main fuel for the boiler is wood chips. Coal and rubber tire chips are also used as supplements. Type of the boiler is ICFB (Internal Circulating Fluidized-bed Boiler), which maximum continuous rating is 105 t/h, while its rated power output is 25 MW. Its power generation efficiency is 32%, a high figure for biomass power plant. This high efficiency is achieved by: high-temperature, high-pressure steam conditions; the use of an in-bed superheater; the use of a high-pressure feed water heater; use of a water-cooled condenser. Following the commissioning, this power plant has been operating for 167 days since a scheduled inspection carried out in May, 2009. Usually a power output is 24 MW during daytime, and during the night, power output is controlled according to the factory load demand.

Keywords
Internal circulating fluidized-bed boiler, Biomass, Steam turbine, Generating power efficiency, Boiler efficiency, Wood chip, Renewable energy, In-bed super heater

by Ryoji TSUKUI
A biomass conversion plant, located in Joetsu, Niigata Prefecture, capable of treating composite biomass and producing biomass products for various effective use, has started operation since October 2009. Biogas generated during methane fermentation of food wastes, as well as wood from tree thinning of forests, is put to use as fuel for drying sewage sludge, and the dried sludge used as cement material. Part of the wood from thinning is molded and made into pellet-form fuel. As such, this plant effectively converts biomass wastes into biomass energy. Favorable feedback is being reported on its continued operation.

Keywords
Biomass, Food wastes, Methane fermentation, Compound treatment, Effective use, Sewage sludge, Woody pellet, Unused, Biogas