Concentration and amount of deoxidizer and hydrazine added to the 0.02MPa deaerator
Thread Content
Dear sea friends, we have a new project, and the boiler water deaerator requires the addition of deoxidizers and hydrazine. I would like to ask: what are the different types of deoxidizers available currently? Should they be added in pure form or as a solution? If used as a solution, what should be the appropriate mass percentage, and what should be the dosage level? At the same time, there is also a factor that increases hydrazine; I’ve seen some sources suggest that the mass fraction should be controlled between 0.2% and 1%. Is that correct? The range seems quite wide to me Also, what is the appropriate amount for dosage control? We are a 140-ton deaerator with an operating pressure of 0.02 MPag.
Is it reasonable to add our deoxidizer to the feed pipeline of the demineralized water, and to add hydrazine at the bottom of the deoxidizer? Looking forward to everyone's answers.
That can’t be right; hydrazine is an oxygen scavenger. Didn’t you make a mistake? It’s ammonia that’s added to the bottom of the deaerator, right? Do you use a spiral-walled deaerator?
I thought it was a mistake too, but that’s exactly what happened! We use thermal deoxidation; in addition, we employ deoxidizers for deoxidization. At the bottom of the deoxidizer, hydrazine is used to adjust the pH and remove trace amounts of oxygen.
Your deaerators are not large, so thermal deaeration should be sufficient to meet the requirements. Our deaerator has a capacity of 420 t/h; the level of dissolved oxygen varies, but it never meets the specified standards. It’s better to avoid using hydrazine for deaeration – it’s too dangerous
It is used to provide BFW for conversion and ammonia synthesis.