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Ebara Engineering Review No.198

Turbomachinery Blade Optimization bya 3-dimentional Inverse Design Method - 4th Report, a Hybrid Design System based onInverse Design and Optimization Algorithm -

by Akira GOTO, Kosuke ASHIHARA, & Mehrdad ZANGENEH

The effectiveness of a 3-dimentional inverse method for ideally determining blade configurations, by defining ideal flow fields and conducting numerical analysis for realizing such configurations, had been discussed in the previous three reports. This 4th report introducesa technique by which turbomachinery blade configurations are automatically optimized by a hybrid system constituting 3-dimensionalinverse design, CFD (Computational Fluid Dynamics) analysis and optimization algorithm. An actual multi-objective optimization example is discussed, in which the initial value dependency of automatic optimization and the dependency of optimization algorithm had been studied, after which both the efficiency and suction performance of a mixed flow pump impeller had been optimized. Furthermore, an example indicating that this method is capable of improving the efficiency and pressure characteristics of a centrifugal compressor impeller over a wide flow range is introduced.

Keywords
Inverse design, Computational fluid dynamics, Optimization algorithm, Blade design, Turbomachinery, Pump, Compressor

Recent Topics in Measures Against the Water Hammer Phenomenon

by Fuminori ETOH

One important factor that needs to be coped with when designing and planning a water conveyance system is the water hammer effect which occurs in pipelines. Working out measures against this is imperative, as this effect can lead to damage on equipment and in the pipeline. EBARA uses an exclusive fluid dynamic, transient phenomenon analysis program (the TRAP Ⅲ program), based on the characteristic method, to calculate and study water hammer effects. The following introduces the results of studies made on a few, relatively particular cases of actual water hammer occurrences, namely cases of slamming at a check valve, water hammer effects in aplant, a water hammer effect with a water column separation, and air in a pipeline causing an unexpected phenomenon.

Keywords
Water hammer, Protection against water hammer, Characteristic method, Slam, Water column separation, Air in pipeline, Air valve

A Study on the Decomposition of Endocrine Disruptors and Dioxins by an Ozonationand Advanced Oxidation Processes

by Sota NAKAGAWA, Kaori TSUTSUMI, Mitsuru Imai, Kazuyoshi TAKEDA, & Toshihiro TANAKA

The effects of O3 treatment and AOP (Advanced Oxidation Processes) treatment on the decomposition of endocrine disruptors were investigated by using a continuous type pilot plant. Reaction kinetic evaluations of these processes were also carried out. In this study,the endocrine disruptors were classified into 2 groups: (1)DXNs: dioxins and (2)EDs: endocrine disruptors other than dioxins. For the case of DXN decomposition, highly concentrated DXNs in an incinerator washwater were degraded by UV/O3 combined treatment. Influence of O3 dosage and forms of DXNs on the reaction rate constant were evaluated. The incinerator washwater was sampled froma scrubber, which was used for the flue gas treatment of a garbage incinerator facility. For the case of ED decomposition, the effects of O3 dosage on the reaction rate constant were investigated during O3 treatment of secondary treated sewage. Also, a comparison was made on the degrad ability for the above 2 groups. The following results were obtained. (1) The DXNs contained in the incinerator washwater had different decomposition properties depending on the particle size of suspended solid. Above a particle size of 1.0 m, the reaction rate constant was relatively small and the DXNs were relatively non-degradable. On the other hand, when suspended solid particle size was below 1.0 m, the reaction rate constant was large and the DXNs wererelatively degradable. (2) The amount of decomposed DXNs per consumed O3 increased with the increase of DXN concentrations in the influent and higher DXN decomposition efficiencies were obtained. (3) The reaction rate constant in the ED decomposition waslarger than that in the DXN decomposition, and the EDs were found to be relatively easy to be decomposed. Once DXNs on the suspended solid particle size larger than 1.0 m in the incinerator washwater were non-degradable, we found that they should be filteredand concentrated separately prior to the AOP treatment to ensure an efficient treatment.

Keywords
Ozone, Advanced Oxidation Processes, Dioxins, Endocrine Disruptors, Incinerator washwater, Sewage

The Feasibility of the Combined Municipal Waste Treatment System

by Norio YAMADA, & Masaaki NISHIMOTO

A feasibility test for a combined municipal waste treatment system was conducted. This system features the combination of methane-fermentation and incineration for treating highly concentrated organic wastes. Classifying organic waste enables the recovery and reuse of heat from fermentation, as well as maintaining the calorific amount of flammable waste. Adding new technical capabilities, such as an ammonium recovery, to this system can further enhance its treatment efficiency.

Keywords
Methane fermentation, Organic wastes, Biogas, Incineration, Ammonium, Energy, Garbage, Nightsoil

Line-focusing of Ultrasonic SV Waves by an Electromagnetic Acoustic Transducer

by Toshihiro OHTANI, Hirotsugu OGI, & Masahiko HIRAO

The design principle of line-focusing electromagnetic acoustic transducers (LF-EMATs) and the results of a feasibility test for detecting slit-type defects in metals are discussed. Each of the LF-EMATs, which excites shear vertical (SV) elastic waves and focusesthem to a line in a metal body, consisted of a permanent magnet block and meanderline coils. The spacing of the coils was continuously varied so that excited SV waves became coherent on the focal line after traveling oblique paths. The measurement directivity of generationand reception indicated a sharp peak in detecting slit defects at the bottom surface of a steel block on which the focal lines were located. Portions of scattered defect signals were received by the same EMAT. When operated at 4 MHz, the LF-EMATs were found to be capable of detecting slits that were deeper than 0.05 mm. Sensitivity decreased with lift offs and the LF-EMATs were usable up toa liftoff of 0.6 mm.

Keywords
Electromagnetic Acoustic Transducer, Non-contacting Evaluation, Directivity, Defects

The Gaikaku Housuiro Drainage Pump Station - Fourth Report: Operation and Control Equipment -

by Shigeo TAKITA, Koji SAKAKURA, Jun ABE, Masao KOIKE, Tetsuo TAKABE, & Shinjiro MAE

EBARA fs Floodway Management System, currently in operation at Tokyo fs Outer Metropolitan Flood Control Channel and pump stations, totally monitors and controls external excess water from four rivers. This water is discharged into the Edo River via an underground waterway. This system is reliable, fully capable of monitoring and controlling the complex open and closed conduits. The following outlines its functions and introduces actual operational data.

Keywords
Underground waterway, Operation at open and closed complex conduit, Integrated control, Improvement in reliability, Horizontal dispersion of function, Vertical dispersion of function, Dual system, Automatic control, Fiber optic network, Asynchronous transfer mode

Downsized Facility for Oosawagawa Pumping Station

by Hiroyuki SAITO, Eiji KAWABE, & Hirokazu ISHIHARA

EBARA's downsized pumping facility, representing various innovative techniques and equipment (optimized pump configurations, driving equipment, power supplies and incidental facilities) has been installed at Oosawagawa Pumping Station, Akita Prefecture. This facility takes up only 60% of the area needed for a conventional such facility. Moreover, this facility has not only achieved a saving inconstruction cost but is also achieving a saving in maintenance and inspection cost. Full consideration had been given to noise, emission and malodor prevention, thus minimizing the impact on the environment in and around the pumping station.

Keywords
Siphon type pump, Power generator at end of the shaft, Gas turbine, Reduction gear with air cooling system

Nanbu Drainage Pump Station in Akita Prefecture

by Mitsuharu SUZUKI, & Masatoshi TAKAGI

The Nanbu Drainage Pump Station in Akita Prefecture has recently been modified with EBARA's new cost-efficient, highly reliableand easily operated, high-speed compact pumps and other equipment. An innovative operation support system, which greatly takes thework load off the operators, as well as air cooled motors and reduction gears, and waterless lubrication of main pumps are featured. The following outlines the modifications made, and introduces operational data.

Keywords
Drainage pump station, Saving in construction cost, High speed & compact pump, Reliability, Repair construction