Technologies

Market leading technologies coupled with the highest quality services

Ebara Engineering Review No.190

Modeling of Bolt-flange Assemblies for the Vibration Analysis by Finite Element Method

by Shijie GUO, Michiko ISHIDA, & Tatsuo HINATA

A modeling method, based on the contact of flanges, is proposed for the vibration analysis by FEM (Finite Element Method) of structures with bolt-flange assemblies. As flanges deform elastically when connected by bolts, they are usually not in full contact. In the modeling, two connected flanges were treated as a continuous integrated body throughout the contact zone, while the non-contact areas were modeled as free surfaces. The effectiveness of the modeling method was confirmed by a simple experiment. Influences on the contact areas by the number of bolts, the diameter of washers, and the thickness of flanges were also investigated. Results indicated that there was little influence by the number of bolts on the contact area surrounding a bolt, but that there was a rapid increase in this contact area along with an increase in the flange thickness. Furthermore, as an example of application of the modeling method, eigen value analysis of the motor pedestal of an actual vertical pump was done and the results compared with measured data.

Keywords
Bolt-flange assembly, Vibration, Finite element method, Contact

Suppression of Rotating Stalls in the Radial Vaneless Diffuser of a Centrifugal Fan

by Hiroyoshi WATANABE, & Hideomi HARADA

A study was made on the suppression of rotating stall in the radial vaneless diffuser of a centrifugal fan. A plate was attached to the internal wall downstream of the inlet of the diffuser to control periodical fluctuations, which cause rotating stalls, in the ring-shaped reversed flow region. Test results indicated that, insofar as the scale of the present study is concerned, attaching an appropriately sized plate at an appropriate location and having a clearance between this plate and the shroud wall were effective in suppressing rotating stalls.

Keywords
Rotating stall, Diffuser, Impeller, Reversed flow, Suppression method

Condensing and Boiling Heat Transfer Coefficients of a Water-Ammonia Mixture

by Tai FURUYA, & Yutaka MORI

A study on the prediction of heat transfer coefficients of a water-ammonia mixture for power generation using Kalina Cycle was carried out to verify the heat recovery effectiveness of this mixture. It was found that prediction of condensing heat transfer coefficients of a falling film type condenser was possible by using a simple, one-dimensional film model. That of boiling heat transfer coefficients was possible by power averaging each heat transfer coefficient of pool boiling and forced convection. There was relatively good correlation between the reduced equation and experimental results, although such correlation was limited to low heat flux regions.

Keywords
Kalina cycle, Multi-component mixture, Power generation plant, Heat recovery, Water-ammonia mixture, Thermal and physical property, Condensing heat transfer coefficient, Boiling heat transfer coefficient, Phase change, Forced convection

Behavior of Reduced Lead Content in Molten Fly Ash and Bottom Ash Slag

by Takeshi KIKUCHI, Ryuji UCHIDA, Shinya TAKENAKA, Yasuto YAMADA, Shigeru ASAI, Yoshikazu OKABE, & Ken KURATA

A study was made on the lead concentration in compacted fly ash and bottom ash slag produced from municipal waste incinerated in a commercial plasma ash melting system. The ash mixing percentage was 14-20% and the furnace temperature was 1400-1500°C. It was found that the lead concentration was reduced to 50 mg/kg, a feat considered difficult for the case of non-compacted ash under the same conditions. A test was conducted using a melting pot to study the reduction factors. Non-compacted fly ash (25%) was added to crushed bottom ash and mixed, and heated to 1400-1500°C for 15-60 minutes. A 90% reduction in lead concentration (to about 100 mg/kg) was observed after a heating of 15 minutes. As for the test using an actual plasma ash melting system, the greater reduction in lead concentration was attributed to a more favorable ash mixture by the compacting of fly ash.

Keywords
Plasma, Compacted fly ash, Bottom ash, Slag, Vaporization of lead compounds, Melting, Basicity, Viscosity

The Development and Application of a New Product Data Management System

by Kazuhiro ESAKI, Kiyoshi KOBAYASHI, & Toyomi NISHI

A new computerized PDM (Product Data Management) system has been developed and put to actual use since last year. This system manages parts data throughout a product's entire life cycle, including that during a product's order reception, development, design, manufacturing,after-sales services and on-site maintenance, thus greatly enhancing work efficiency. Its application is enabling overall BPR (Business Process Re-engineering), including a standardization of PN (Parts Number) codes and PS (Product Structure) elements, as well as an improvement in design and production procedures.

Keywords
Product data management, Parts number, Parts configuration, Global, Overall life cycle

Wide Area Control and Facility Management System for Pumping Stations

by Kinji TAKAHASHI

A new wide area control and facility management system has been developed for use in pumping stations. This unprecedented computerized system features the use of multimedia, including computer graphics and sound output, and the Ethernet. This system features a multimedia gateway, monitoring CRTs, an application control server, a facility data management server, a web server, and web terminals. The system for the plant includes an Ethernet connected system featuring multimedia gateways, local processors, ITV cameras, and real time data input capabilities. This system enables monitoring, control, management, and immediate response to emergency situations at pumping stations.

Keywords
Web, Fiber optic network, Open system, Wide area, Flexibility, Multimedia, Integrated human interface, Database, Information technology

Water Management and Control System of Taiki-cho

by Akira MOCHIZUKI, Takahumi KOGUCHI, Tohru HORIGOME, & Yoshikazu NARASHIMA

The Taiki-cho water management and control system has made it possible for overall management, monitoring, and control of all waterworks facilities in the Taiki-cho district, in Hokkaido, including water intake facilities, water treatment plants, water reservoirs, water meter pits, etc. Its human interface equipment features mini-graphic CRT display panels and CRT monitoring and operation display panels, both of which have enabled a significant improvement in reliability. The system also features the use of data storage and processing computers, CRT graphic computers, and large capacity workstations.

Keywords
Water management and control system, Waterworks, Work station, Human interface, Water purification plant

CALS System for Operation and Maintenance Management of Drainage Pump Stations

by Yuichiro HIRAKO, Tetsuro KOJIMA, & Satoshi INOUE

A CALS (Continuous Acquisition and Life-cycle Support) system has been developed and implemented for the operation and maintenance management of drainage pump stations. This system uses the Intranet and multi-media, linking pumping stations with construction offices by fiber optics, as well as by the Ethernet. A fire-walled network enables secure monitoring, control, and I/O of data.

Keywords
Construction CALS, Continuous Acquisition and Life-cycle Support, Facility management system, Intranet, Water facilities, Emergency measures, Operation and maintenance, Life-cycle support, Maintenance

Water Management & Control System for Gojoh District, Muika Town, Niigata Prefecture

by Akira MOCHIZUKI, & Norikazu YUURA

A water management and control system has been developed and put to use for Gojoh District of Muika Town, Niigata Prefecture. This system features remote monitoring and control, as well as automatic control of gateways and flow rate adjustment, making use of water level meters, flow meters, and ITV cameras. The water intake for three rivers is regulated.

Keywords
Management of intake flow, Automatic control, Connection control, Flux, Water level, Water gate, Screen, Hydraulic plant, Water management, Industrial television camera

Irrigation Water Monitoring, Control, and Management System for Tendo District, Yamagata Prefecture

by Takafumi KOGUCHI

EBARA's irrigation water monitoring, control, and management system has been put to use for rice paddies at Tendo District, Yamagata Prefecture. This system manages three pump stations, as well as water reservoirs, water gates, and waterways, which are used for the irrigation of an overall rice paddy area extending 1,127 ha. Hydrological factors were analyzed, taking full consideration of equipment characteristics, capacities and functions, and control methods at each facility, to enable an optimal labor-saving, safe system.

Keywords
Concentrated control, Pumping up equipment, Multistage pumping up, Multistation control, Remote control, Flux control, Picture monitor, Labor-saving

Facility Information Management System for Multipurpose Pumping Stations of the Kita-Chiba Water Conveyance Project

by Hiroshi OGAWA, Katsushi CHO, Kouji ABE, Toshinobu SETOH, Yuichiro HIRAKO, Yoshihiro UCHIDA, & Akito YAMAGATA

The following is a second report regarding the Kita -Chiba Water Conveyance Project and touches on the facility information management system for two multipurpose pumping stations and water conveyance facilities set up in line with this project. The said system is computerized and is capable of wide-area monitoring and controlling various facilities and systems. Such include the static Scherbius system (for the fail-safe of 9 power generators and stepless capacity control), computer system for coordinated control of the pumping stations and water conveyance facilities, and the human interface for monitoring and operation. Included is an outline of a one-year overall trial run.

Keywords
Kita-Chiba Water Conveyance Project, Static Scherbius, Coordinated control (of No.1 and No.2 pumping station), Computer for coordinated control, Human interface for monitoring and operation, Facilities information management system, Stepless capacity control, Wide area monitoring, Automatic control coordinated with No.1 and No.2 pumping stations, Automatic control of each pumping station

Automatic Combustion Control System for Water Injection Gas Cooler in Stoker Firing Waste Incineration Plants - Installed System in Uma Clean Center -

by Takenari INOUE, Hideaki HARADA, Naomi ONUKI, Tomoyuki SONE, & Yasuyuki GODA

EBARA's Stoker Firing System, featuring automatic combustion control, has been installed at Uma Clean Center, Ehime Prefecture. This system, equipped with a fuzzy controller, is capable of stable, complete combustion, and controls the generation of dioxins and other hazardous matter. The following outlines this system.

Keywords
Automatic combustion control system, Fuzzy controller, Dioxins, Stoker, Municipal solid waste, Incinerator, Water Injection

TIF Fluidized-bed Municipal Waste Incineration System & Materials Recovery Facility - Isesaki City Clean & Recycle Center 21 -

by Kiyotaka ISHIKAWA, Masanori ISHIKO, Kikou UCHIYAMA, Minoru TAKEUCHI, Hideki ASAI, Takayoshi HISAMATSU, & Norifumi INABA

EBARA's fluidized-bed, municipal waste incineration system (treatment capacity: 70 t/day, 3 furnaces) and materials recovery facility have been installed at Isesaki Clean & Recycle Center 21, Gunma Prefecture. The incineration system sufficiently meets standards stipulated in the government's new pollution prevention guideline. In particular, Dioxin emission is minimized to below 0.1 ngTEQ/m3NTP, made possible by the blow-in of fine activated carbon and the use of catalysts. Waste heat from the incineration process is recovered and utilized to produce steam by a waste heat boiler. The steam is sent to a steam turbine for power generation (1980 kW) and the generated power is either used inside the plant or sold as excess electricity to the local power company. The steam is also used inside and outside the plant as a heat source for hot water and such. The materials recovery facility treats non-combustible and bulky wastes, and recovers materials as resources. It includes a public participating process and is contributing to waste reduction and recovery.

Keywords
Fluidized-bed incineration system for municipal waste & materials recovery facility, DXNs, Catalyst, Steam turbine generator, Activated carbon, Waste heat boiler, Pollution prevention, Automatic startup and shutdown system