Ebara Engineering Review

by Kenichi SUGIYAMA
SiC ceramics, which have excellent properties for frictional wear in water lubrication, are used for sliding bearings lubricated in water; however, abnormal wear may occur in ultra-pure water lubrication. In this study, we manufactured specimens with a diamond layer coated on the surface of SiC ceramics by vapor phase synthesis, and evaluated their tribology and erosion corrosion characteristics in water. For the tribology characteristics in tap water and ultra-pure water, no big difference was observed between the SiC ceramics and diamond layer. On the other hand, for the erosion corrosion characteristics in ultra-pure water, the SiC ceramics were significantly eroded while the diamond layer had little erosion, showing its excellent resistance property. Therefore, we conclude that the diamond layer is suitable for sliding bearings lubricated in ultra-pure water.

Keywords
SiC, Diamond layer, Ultra-pure water, Erosion corrosion, Sliding bearing, Tribology

by Kazuhiro KANEDA, Yosuke HARADA, & Nobuhiro HIGAKI
The model F3100, a long-selling water-supply package for use in commercial and residential buildings, was remodeled in October 2013. The new product, by adopting top runner motors to meet the efficiency control standard due to be effective from fiscal year 2015, and by running in the newly-developed E-mode operation, has evolved into a model with a higher degree of energy efficiency. The first “Save Energy Pump series” water supply product to hit the market, it also features enhanced ease of operation and installation as well as an improved backup function in the event of equipment failure.

Keywords
Energy-saving, Top runner motors, Packaged pump system, E-mode operation, Estimated constant end-pressure control, Backup function, Energy efficiency regulations for motors, Inverter, Simple operation, Simple construction

by Yohei TAKAHASHI, Maina HOSHI, & Masazumi OBA
Aseptic filling systems used at beverage factories discharge a large volume of water used for washing plastic bottles. Chemicals from the disinfectant for bottles need to be eliminated to recover the discharged water. For this purpose, Swing Corporation has developed ARRoWS® discharged aseptic rinser recovery system that applies a combination of a reduction tower in a unique structure, anion exchange tower, and RO flow. Benefits of ARRoWS® include the following.
1) It inhibits the growth of microbes in the recovery equipment.
2) It eliminates the tiny quantities of organic constituents from plastic bottles or disinfectant.
3) It increases the rate of recovery of wastewater.
4) It prevents generation of highly corrosive wastewater.
5) It is space-saving.

Keywords
Aseptic filling system, Beverage bottling, Bottle rinser, Waste-water recovery, Reduction tower, Anion exchange tower, Rinser waste water, Peracetic acid, Hydrogen peroxide, Sterilized water

by Motohiko NOHMI
This paper presents basic information about the pump cavitation phenomenon. Firstly, the reason why the cavitation occurs is explained using the saturated vapor pressure curve of water. Water vaporizes vigorously when the water pressure drops to the saturated vapor pressure determined by its temperature. This is the principle of cavitation occurrence. In a fluid pipe line, water increases speed at a contraction section, lowering the static pressure at the same time. Then, when the pressure drops to the saturated vapor pressure, cavitation occurs. In the case of pumps, cavitation which occurs at the suction side of a blade because of the pressure drop is typical example. In addition, in transient phenomena, caused by sudden closing of a valve or pump trip, water column separation that is a kind of cavitation occures. One of the problems caused by pump cavitation is pump head drop which makes non-attainment of a desired pressure. In relation to this, suction performance curve, NPSHA, and NPSHR are explained in this paper.

Keywords
Cavitation, Boiling, Saturated vapor pressure, Suction surface, Water column separation, Net positive suction head (NPSH), Suction performance curve

by Ryotaro KARAKI
We have since the mid-1970s manufactured and sold water supply equipment (packaged pump systems) to supply water to facilities such as collective housing and office buildings. In this article, we describe characteristics of various water supply systems, including transition of our products. Then, we will follow this up by technical information on water supply equipment to be introduced to you in several articles in a series, providing the installation method of water supply devices, details of different water supply methods, their maintenance and inspection, and the related standards.

Keywords
Water supply system, Direct connecting system, Reception tank system, Direct water supply system, Direct connecting booster pump system, Elevated water tank system, Direct supply system, Large pressure tank system, Small pressure tank system, Variable frequency control system

by Shusaku KAGAWA, Hiroyuki KANEKO, Takaki SAKURAI, & Hidenobu OKAMOTO
This report described as newly designed and developed a reverse running pump turbine that operates at a higher fixed rotational speed (2980 min－1) and higher head than conventional models. The newly developed reverse running pump turbine was designed using CFD based on conventional models; the performance of the final design was verified by a model test. The adjustment of the QH performance of reverse running pump turbine operating at fixed rotational speed, which had not been fully clarified, was also examined by CFD and a model test.

Keywords
Turbo machinery, Reverse running pump turbine, CFD (Computational Fluid Dynamics), Model test, Performance

by Keita YAGI
A high-efficiency and high-performance planarization technique for gallium nitride wafers has been developed based on catalyst surface referred etching (CARE), a new polishing method utilizing catalytic surface reactions. A two-step polishing process consisting of STEP1 (increasing the removal rate by means of photo-electrochemical reactions) and STEP2 (achieving high-precision surface planarization by means of catalytic oxidation using noble metal) was proposed, demonstrating that the polishing of a lapped surface could be completed in 50 minutes. The polished surface was also found to be planarized at the atomic level and free of damage.

Keywords
Gallium nitride, Polishing, Catalyst, Photo-electro chemistry, Platinum, Quartz

by Hirofumi NAKAYAMA, & Shinobu ISHIZUKA
New products made of PENTAM® plastic have been developed. The new developments include self-priming pumps with high self-priming capacity, high-capacity/low-head mixed flow pumps, and nonreturn valves capable of reducing the pressure rise due to water hammer. Thanks to the corrosion resistance and wear resistance imparted by PENTAM® plastic, all of these products can be used in a wide range of applications.

Keywords
PENTAM® plastic, Self-priming pump, Mixed flow pump, HAMMER SOFT nonreturn valve, Water hammer, Corrosion resistance, Wear resistance, Impact resistance, Seawater intake, Seawater pump unit

by Munetoshi FUJII, Takashi FUKUMOTO, & Sakae SHIMIZU
The Shinkawa-ugan Drainage Pump Station, located in the downstream area of the Shinkawa River, is a pump station with a long history, commencing operation in 1953. Because of its deterioration, the new pump station was constructed next to it, and with the replacement of all pump equipment, operation began in 2012. With this historic overall renovation, numerous innovations have been adopted with a focus on improving the maintainability of the equipment, based on Ebara’s technologies for pump-related equipment, which includes reducing running costs by improving the efficiency of pumps and motors, improving corrosion resistance, and retaining the ease of use from the old pump station. Also, continuous drainage was being performed by the remote monitoring operation in the pump station and although transferring the operation from the old station to the new was a challenge, the relocation was completed in a short period of time without hindering the operation as a result of the thorough field investigation and meticulous work.

Keywords
Drainage pump station, Renewal work, Horizontal-shaft mixed-flow pump, Vertical-shaft axial-flow pump, Pump efficiency, Motor power factor, Corrosion resistance, Erosion, Maintenance, Changeover

by Ryuichi ISHIKAWA, Takaharu NARITA, Sumihiro YOSHIKAWA, & Shigeru YAMAGUCHI
Improvement work, which aims to prolong the life of the facilities while improving their functions, is being carried out at existing MSW incineration plants. The improvement of functions is for reducing CO2 emissions as a measure to prevent global warming. For this purpose, there are improvements with heat use and the reduction of energy consumption at the plants. The fluidized-bed incinerator is equipped with features to slash power consumption, based on the results of the fluidized-bed gasification and ash melting system. It is now being reported that the improvement work was carried out at the fluidized-bed incineration plants with a water spraying exhaust gas cooling system, with which the improvement of heat use is difficult, and achieved a 20~30% reduction in plant power consumption.

Keywords
Fluidized-bed, Incinerator, Improvement, Life extension, Green-house effect, CO2 emission, Municipal Solid Waste (MSW)

by Arihiro OKAMOTO & Shinya ABE
The twin interchanging fluidized-bed (TIF) incinerator is Ebara’s unique technology that has been marketed since 1984. It is currently in operation at 71 plants in Japan and 31 overseas plants.
For the Hiratsuka City “Kankyoujigyou Center” (environment management center), which was completed at the end of September 2013, Ebara delivered the TIF furnace as the advanced fluidized-bed incinerator. The advanced fluidized-bed waste incineration facility provides significantly improved performance through state-of-the-art technologies based on the past development and installation of fluidized-bed gasification and ash melting systems, such as lower air ratio operation and high-efficiency power generation.
This paper describes the features of the advanced fluidized-bed waste incineration technology with reference to operation data at the Center and discusses the future perspective of fluidized-bed waste incineration technology.

Keywords
Fluidized-bed, Waste, Incinerator, Energy from waste (EfW), Exhaust gas recirculation, Air ratio, Combustion control, Sulfur oxides

by Takao HAGINO, Daisuke KOGA, & Ryoji TSUKUI
Magnesium ammonium phosphate (MAP) particles are naturally produced in digested sewage sludge and typically discharged with dewatered sludge cakes during a sludge dewatering process. However, MAP can be reused as a fertilizer or a fertilizer ingredient if it can be separated and recovered directly from sludgebeing . In this study, two types of tests were conducted to verify the performance of a novel phosphorus removal process for MAP recovery. One was continuously conducted using a full-scale MAP separation plant equipped with a vibrating screen, a hydrocyclone, and a revolving cylindrical type flowing film separator. The other was conducted using a pilot-scale plant combining a MAP separation system and a sludge dewatering system. The test results have shown that the process can recover approximately 50% of phosphorus from sewage sludge and significantly improve sludge dewatering performance. It has also been found that the initial cost of the process may be covered by the reduction in maintenance costs.

Keywords
Phosphorus, Recovery, MAP, Sewage, Sludge, Dewatering, Fine particles, Hydrocyclone, Cost, Dewatered cake

by Akira SUZUKI, & Keisuke IKEDA
Since the first system was introduced in Japan in 1990, vacuum sewerage systems have been operating in many regions of Japan. The earliest facilities using the systems are as old as twenty-four years, and many of them will require renewal in the coming years. Thus, the concept of stock management has been proposed to respond to demands to extend the service life of the facilities through timely and appropriate repair and renewal. EBARA realized the functional improvement of the components of the systems, namely (1) valve pit, (2) vacuum pump, and (3) vacuum valve failure monitor at the time of renewal. Even in old systems that require renewal, these improved components allow the achievement of higher performance while ensuring the systems’ compatibility, thereby offering stable operation equivalent to that in the latest systems.

Keywords
Vacuum sewerage system, Renewal, Stock management, Functional improvement, Valve pit, Vacuum pump, Vacuum valve failure monitor

by Hironari OKAWA, Koji KAWATA, Youichiro NAGASAKI, Manabu TAKAHASHI, & Takuya FUJIMURA
Repair work on fire safety equipment in the Airport North Tunnel was conducted with the traffic controlled during nighttime hours, since the tunnel had to remain in service. The work was difficult due to time constraints and the requirement to maintain the functioning of the fire safety equipment. However, it was successfully completed by considering work methods and safety measures.

Keywords
Tunnel, Fire safety equipment, Fire hydrant, Tunnel sprinkler, Fire extinguisher, Automatic valve

by Nobuhiro HIGAKI & Ryotaro KARAKI
Solar radiation test equipment that can provide pseudo-sunlight irradiation to simulate the effects of solar radiation on outdoor water supply facilities, as well as a temperature-controlled room with ambient temperature control have been installed. The temperature-controlled room is large enough to allow easy transport and installation of considerably large water supply systems. Accommodating a water tank and power supply facilities supporting products for overseas markets, the test equipment facilitates the simulation process with pump operation.

Keywords
Solar radiation test equipment, Temperature-controlled room, Irradiation distance, Effective irradiation range, Non-uniformity of irradiance, Metal halide lamp, Modurated light, Thinned-out lighting, Full lighting

by Shinya ABE, Arihiro OKAMOTO & Kazuo AWAZU
We have completed the construction of the Hiratsuka City Kankyo Jigyo Center (Environment Management Center), a fluidized-bed waste incineration facility that treats waste collected from Hiratsuka City, Oiso Town, and Ninomiya Town. As an advanced facility with a capacity of 315 t/d, the Center is designed to be compatible with a recycling-based society, providing high-efficiency power generation, 100% residue recycling, and an advanced flue gas treatment system. We were awarded the DBO (Design-Build-Operate) contract for the Center in May 2010 and completed the construction in September 2013. In October 2013, we started a 20-year operation and maintenance business with the aim of achieving both operating cost reduction and provision of high quality service. This report outlines the facility and the business.

Keywords
Fluidized-bed, Waste, Incinerator, Energy from waste (EfW), High-efficiency power generation, Recycling, Sulfur oxide, Design-Build-Operate method, Partial load operation, Power output control

by Osamu TATEISHI, & Kaname KURITA
This paper presents deep well submersible canned motors for the global market. The market for deep well submersible motor pumps is recently expanding with the increased use of well water due to population growth and economic development in emerging countries. Therefore, Ebara Corporation has developed deep well submersible canned motors ZBH4N, ZBH6N, and ZBH8N, which provide the high quality, reliability, and durability required by the global market, have high thrust load bearings, and meet NEMA standards. The company has launched the products in the global market.

Keywords
Submersible canned motor, High reliability, High durability, High thrust load bearing, Deep well, High depth, Starter, Single phase motor, Three phase motor, Clean water

by Hideharu WATANABE
This paper describes the design enhancements of cryogenic pumps and expanders for the floating liquefied natural gas (LNG) vessels applications, such as floating storage regasification units (FSRU). The conceptual design of two-phase expander is also discussed for power recovery applications.

Keywords
LNG, Cryogenic pump, Expander, Power recovery system, Shaft stabilizer, Two-phase fluid

by Yoshinori OJIMA, Naoya YOSHIDA, & Hiroyuki KAWASAKI
Scientific instrument, such as analytical equipments and electron microscopes, uses small-capacity vacuum pumps. The compact dry vacuum pump Model PDV50 has been developed for use in these applications. This pump is a positive displacement dry vacuum pump with two synchronously rotating motor rotors; the innovative advantage of the pump is that the use of a proprietary motor with a magnetic coupling eliminates the necessity of timing gears. Without timing gears, the pump features a simple structure and requires no lubricating oil, allowing fast rotor rotation. It is also compact and weighs only 10 kg. Since the pump module can be mounted in any orientation, the pump can be flexibly installed. In addition, the pump has an operating noise level of 53 dB(A) or less thanks to reduced machine noise and a noise suppression package.

Keywords
Dry vacuum pump, Twin shaft synchronous motor, Timing gear, Screw, Compact, Rotary vacuum pump, Scroll pump, Diaphragm pump, Analytical equipment, Electron microscope

by Nobuya AZUMA
A next-generation stoker type incinerator system manufactured by Ebara Environmental Plant Co., Ltd. has been delivered to the Arakawa Clean Center in Fukushima City to simultaneously achieve high-efficiency power generation and ash melting treatment. The plant generates 440 kWh (FY2010) of electricity per ton of incinerated waste and has relatively high power generation performance among incineration plants with an incineration capacity on the order of 200 t/day. The plant also achieves a landfill rate of about 4% by melting both bottom ash and fly ash. The plant was damaged by the Great East Japan Earthquake (in March 2011). However, it was immediately restored by Ebara Environmental Plant Co., Ltd. and restarted its incineration operation eight days after the earthquake. Since the Great East Japan Earthquake, the plant has continued to reduce the volume of bottom ash through ash melting treatment, contributing to extending the life of final landfill sites, which was expected to run out after the earthquake.

Keywords
Incinerator, Stoker furnace, High-efficiency power generation, Low air ratio combustion, Flue gas recirculation, Plasma type ash melting furnace, Slag, Great East Japan Earthquake, Radioactive substance, Final landfill site