Technologies

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Ebara Engineering Review No.239

Improvement of Leaching Characteristics of TOC from Condensate Demineralizers

by Takeshi IZUMI, & Tatsuya DEGUCHI

Recent nuclear power plants require high purity water to protect nuclear reactors or steam generators from stress corrosion cracking (SCC). It is especially important to minimize sulfate ion leaching caused by oxidative degradation of cation exchange resins in condensate demineralizers during operation.
A uniform particle size (UPS) strong acid cation gel resin with 14% cross-linkage and excellent oxidization stability has recently been developed and applied to condensate purification systems.
For further improvement of water quality, some methods, such as the use of cation overlayers, have been examined to modify the resin bed configuration in condensate demineralizers. We have tested these methods by cold column testing.
We have also developed a new anion exchange resin capable of efficiently absorbing organic leachables from cation exchange resins and evaluated it by cold column testing.

Keywords
Ion exchange resin, Condensate demineralizers, Leachables, Total organic carbon, Cation overlayer, 4-layered bed

Multifunctional variable speed driver for pumps

by Masakazu KOMAI, Kimi HATABAYASHI, & Kenta TSUKAKOSHI

A multifunctional variable speed driver (Model EVFC) has been developed that allows users to willingly and easily achieve energy savings in pump operations.
Model EVFC provides variable speed motor drive control for both induction motors and efficient permanent magnet synchronous motors. It also supports optimum pump control (including pressure and flow controls), multi-pump control, and many pump protection functions based on Ebara’s long-standing expertise.
Thus, model EVFC allows users to achieve energy savings in pump operations and to ensure suitable operation and protection for each application.

Keywords
Variable speed drive, Energy saving, Optimum pump control, Permanent magnet synchronous motor, Sensorless vector control, Motor mount, Multi-pump control, External communication function, Pump protection

Controller for Variable-speed Pumping System (Model EIPC)

by Masayoshi IKEDA, Hironori NINOMIYA, & Hiroyuki TAMURA

A controller for variable-speed pumping systems (Model EIPC) has been developed to allow the realization of variable-speed pumping systems meeting the needs of overseas markets and the local procurement of their components.
The controller supports up to six pump units and provides a flexible selection of pump drive systems. Thus, it allows the optimal configuration of pumping systems according to the specific requirements. EIPC can be used with various inverter products from major manufacturers, facilitating the local procurement of pumping system components in overseas markets. The controller detects low flow rates (pump stop flow) without using a flow switch and promotes maintenance-free system operation. It also ensures easy maintenance of pumping systems at overseas sites by communicating detailed pumping system operation data to a higher-level monitoring system or alerting device.

Keywords
Flow-switch-less, Multi-function display, Estimated constant end-pressure, Constant pressure, Direct connecting booster pump, Reception tank, Variable speed, Pump controller, Inverter, Maintenance-free

Dry Vacuum Pump Model EV-A10

by Atsushi SHIOKAWA, & Hiroyasu KAWASHIMA

Many dry vacuum pumps are used in production lines for high-technology products in the semiconductor, liquid crystal, and photovoltaic industries. In addition, dry vacuum pumps have gradually replaced rotary vacuum pumps in a wide range of industrial fields, such as machinery parts manufacturing, metal working, food manufacturing, and laboratory equipment, for improving work environments, decreasing downtime, or reducing the frequency of maintenance.
The dry vacuum pump model EV-A10 features forced air cooling, constant pumping speed on the atmospheric side, and handling condensable gases, serving a wide variety of applications as described above.

Keywords
Vacuum pump, Dry vacuum pump, Rotary vacuum pump, Multi-stage roots pump, Air cooling, Pumping speed, Condensable gas, Semiconductor, Machinery parts manufacturing, Food manufacturing

Improvement of sludge dehydration by the “Ebagros U-700” series
- To improve sludge dehydration and reduce the water content of sludge cake -

by Takahiro OKAWA, Takayuki MORINAGA, Toshiyuki YASUNAGA, & Takehiko ANDOH

Swing Corporation has developed the “Ebagros U-700” series, a dehydration improver composed mainly of biodegradable cellulose with a short fiber length of 5 or 10 mm.
Recently, the diversification of lifestyles and the evolution of sludge treatment processes have made it difficult to achieve efficient dehydration by using only polymer.
By adding the “Ebagros U-700” series at 1 to 4% of the volume of solid sludge along with a polymer during sludge dehydration, (1) the water content of sludge cake can be reduced, thereby decreasing the amount of sludge to be transported off-site, and (2) improved operation efficiency, including increased sludge treatment throughput, can be obtained.
A long-term pilot test using digestion sewage sludge was conducted at the Miyabuchi sewage treatment plant in Matsumoto City. This paper presents the findings obtained from the pilot test as well as the test results at other plants.

Keywords
Ebagros, Dehydration, Short cut fiber, Sludge, Sludge cake, Biodegradable, Water content, Digestion sludge, Polymer, Dehydrator