To provide a convenient method for preserving an air heater for a long term at a low cost while preventing corrosion effectively.
In the method for preserving an air heater, an additive of one kind or more of sodium carbonate, sodium hydrogencarbonate and magnesium hydroxide is thrown directly into exhaust gas at the post-stage of economizer outlet and at the prestage of an air heater and ash adhering to the air heater is rendered substantially alkaline before a boiler is stopped. After the boiler is stopped and before water washing is ended, the air heater is washed with an aqueous solution added with an additive containing one kind or more of sodium carbonate, sodium hydrogencarbonate and magnesium hydroxide and then it is dried so that the additive remains on the air heater.
SETOGUCHI TOSHIHIKO
MIYAGAWA JUNICHI
TAKEUCHI NOBUO
TOKUNAGA KIKUO
