Induction Heat Tube Extraction for Generating Bank Replacement

Induction is used to rapidly heat generating bank tubes in situ to 1000 C, which causes plastic deformation due to thermal expansion under restraint by the tube sheet (drum). When cooled, the tube shrinks, breaking contact with the drum, providing for ease of removal. A second process has also been developed, and Patented, for the removal of previously over expanded tube stubs from headers and drums. The Heat and Pull^SM method extracts the stub by hydraulic jacking from outside the drum while Induction heating from inside the drum. Prior bell removal is not required, as the bell collapses and is pulled through with the stub. Cost and schedule improvements may be achieved with both Induction Heat Tube Extraction processes. Both processes eliminate the risk of tube seat damage often caused by the traditional tube removal methods of arc air gouging or flame cutting. This paper describes the technology of both Induction Heat Tube Extraction methods as well as developments on current boiler generating bank replacement jobs.