Why must the ferrous sulfide passivation treatment of the equipment be carried out before steam purging of the equipment?
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RT, as the title says. Please give me some advice. . .
Without passivation first, steaming is ineffective; they can also be carried out simultaneously.
What is the purpose of steam cooking?
Steaming can remove residual materials and coke adhered to the equipment itself, but it cannot remove ferrous sulfide. Therefore, there is still a risk of spontaneous combustion during cooking, especially in packed towers where it is difficult to clean thoroughly, resulting in a high risk of fire; hence, passivation must be carried out first.
Maintaining proper humidity is one of the ways to prevent the spontaneous combustion of ferrous sulfide, but boiling alone cannot ensure the complete removal of ferrous sulfide; that’s why passivation is carried out first, followed by boiling, or the two processes are performed alternately. Otherwise, exposure to the air still poses a risk of spontaneous combustion
Could some experienced colleague please explain the principle behind the passivation of ferrous sulfide? And will a reverse reaction occur after passivation, resulting in the formation of ferrous sulfide again?
https://bbs.hcbbs.com/thread-1014474-1-1.html There is relevant information on the second floor of this post for reference; I hope it will help you understand better.