2 replies to this topic

[S.win]

Hi Everyone.

Currently working in a coal fired power plant. As of the moment, the plant is in its commissioning stage and doing some wet lay-up preservation of the feedwater side.

Just would like to ask if dosing of oxygen scavenger has effect on the increase of pH aside from dosing Amine? The commissioining team told us that dosing of oxygen scavenger (carbohydrazide) will help in the increase of pH. I somehow disagree with their notion because as far as what i have read on some literature, dosing of oxygen scavenger only helps remove oxygen which can cause corrosion and pitting while passivating also the metal surface. AND i have also read that too much dosing of scavenger will actually promote copper corrosion at elevated pH due to breakdown of carbohydrazide to ammonia.

The commissioning team in our plant does not even monitor the residual oxygen scavenger which in fact might be critical to copper corrosion. They only check on the specific conductivity for the dosing of amine.

Is this okay or should I say are they doing really the right way where they are dosing Amine and Oxygen Scavenger at the same time and no monitoring of residual Oxygen Scavenger? And will Oxygen Scavenger really increase pH?

I somehow disagree with their explanation and very contradicting to some references from literatures

I hope for a positive feedback to those who will be able to read this.

Thank you

- Win

[breizh]

Hi ,

use the search engine in this forum , the topic has been discussed several times and consider the link attached :

 

https://www.suezwate...1_preboiler.jsp

 

Hope this is helping you.

Breizh

[S.win]

Many thanks breizh. Will look into this.