Development of removal method for the deposit in the boiler system

Nishino, Shohei; Ishiyama, Toru ; Kawasaki, Ichio 

The purpose of this R&D is the development of removal method for the deposit and the countermeasure of corrosion by solute in the boiler system. In the boiler system, sulfur and iron oxide accumulated on the bottom and stiffened on there. Because the property of this deposit changed to strong acidity, then the generating tube was corroded by it. And the leakage, occurred at generating tube, was found at Dec. 2011. The property of deposit was too hard to remove by pressurized water, and width of each pipe was too narrow to remove by mechanical method, because there was several thousands of generating tube every 30 mm on the bottom. Therefore the effect of lab examination, corrosion test based on materials of the generated tube, was evaluated.