Deaerator dissolved oxygen
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Why is the dissolved oxygen measurement in the deaerator taken before adding ammonia rather than after? Why is ammonia used, and not hydrazine?
Adding ammonia is not to remove oxygen, but to increase alkalinity. Oxygen is removed because ammonia cannot react effectively with oxygen in an aqueous environment.
Our company adds ammonia to the feed water of the deaerator, and ammonia is also added to the effluent. The sampling point for the effluent is located at the point where samples are taken before ammonia is added to the effluent, rather than at the point where the chemical is added after that
I just want to ask why the dissolved oxygen measurement port is located before ammonia is added to the water outlet; would it be possible to place the measurement port after ammonia is added?
Is it confirmed that the sampling point is only for testing dissolved oxygen in the feed water? Anything else unexpected? If unexpected changes occur in water conductivity, it can be installed behind the ammonia addition pipe. The purpose of adding ammonia is to adjust the pH value of the boiler feed water; it does not affect deoxidation, but the conductivity of the feed water increases after ammonia is added. You can take samples or add ammonia water, and use a conductivity meter to make a comparison! Additionally, thermal deoxidation is relatively stable, while dissolved oxygen is only an item for random testing.