Decontamination method of heat exchanger and decontamination method

摘要

To include a step (Step S13) of flowing air into a heat transfer tube (304), and setting a flow rate (Qp) of abrasive particles to be mixed into air based on a pressure loss between an inlet (304a) side and an outlet (304b) side of the heat transfer tube (304); a step (Step S14) of calculating a permissible grinding time (tA) required until a curved portion (a point A) of the heat transfer tube (304) reaches a permissible grinding thickness based on the flow rate (Qp) of the abrasive particles; and a step (Step S15) of flowing air mixed with the abrasive particles into the heat transfer tube (304) for a time that is a half of the permissible grinding time (tA) and then backwardly flowing air mixed with the abrasive particles into the heat transfer tube (304) for a time that is a half of the permissible grinding time (tA).