Technologies

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Ebara Engineering Review No.243

Advanced Fluidized-bed Waste Incineration Technology using TIF Furnace

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

Phosphorus Recovery from Sewage and High Efficiency Sludge Dewatering
- Toward the Development of a Self-supporting Phosphorus Recovery Process -

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

Functional Improvement of Vacuum Sewerage Systems and its Effect

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

Repair Work on Fire Safety Equipment in the Airport North Tunnel

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

Solar Simulation System

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

Hiratsuka City “Jiki Kankyo Jigyo Center (New Environment Management Center)”:
Completion of the Construction and Start-up of the Operation and Maintenance Business

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