As powdered scale discharge measures in boilers applied oxygenated treatment, it was
confirmed that the boiler water filling and N2 pressure blow operation, and furnace feed water flow
rate swing and increase operation in boiler blow / boiler circulation / hot water circulation process
were effective in boiler cleanup at plant startup. In addition, we established a method to enable
boiler chemical cleaning for scale removal in a short period outside the periodic inspection period
and adopted it in actual plant.