Koji Ishizeki* and Takehiko Inada**

*Manager, Environmental Plant Engineering & Design Dept., NKK Corporation
**Manager, Planning sec., Environmental Plant Engineering & Design Dept., NKK Corporation

+ Correspondence should be addressed to Koji Ishizeki:
Manager, Environmental Plant Engineering & Design Dept., NKK Corporation
(2-1 Suehiro-cho, Tsurumi-ku, Yokohama 230 Japan)

Abstract

The steam conditions of incinerator plant boilers have been raised from 8-16atg X saturation temperature, in former times when the purpose of the boiler is for cooling down waste gas, to 36atg X 380*C[Celsius degeree] nowadays, when the refuse is regarded as a source of energy. In NEDO's research of "highly-efficient refuse power generation technology development" , 100ata X 500*C[Celsius degeree] is aimed at; useful results are expected also in future efforts. According to the research up to today, it has been revealed that the corrosion conditions are rather more difficult for metal temperature 550*C[Celsius degeree] than 450*C[Celsius degeree], and further material development is underway. In higher temperature/pressure boilers, as superheater tubes are to be exposed to harder corrosion conditions, with bigger superheater heating area, study in design of heating surface arrangement and temperature setting are also necessary. Our design guidelines and 39atg X 400*C[Celsius degeree] actual boiler design procedures are introduced.

Key words: waste-to-energy plant, hot corrosion, superheater tube material, superheater design