Do boilers that use condensate water as feedwater require the addition of phosphates and ammonia?
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Do boilers that use condensate water as feedwater require the addition of phosphates and ammonia?
It’s usually a mixture; it depends on the pressure of the boiler – it’s hydrazine rather than ammonia
Boilers that use condensate as feedwater usually require the addition of phosphates and ammonia. Phosphates can form a protective layer in boilers to prevent the metal surface from corroding. Ammonia can regulate the acidity and alkalinity of water, preventing corrosion and scaling of the water inside the boiler. Therefore, to protect boiler equipment, it is usually necessary to add an appropriate amount of phosphates and ammonia. .
It is necessary to test the condensate water, as well as the boiler feedwater that contains condensate water! Check whether the boiler feedwater specifications can be met, and then decide on the appropriate measures to take based on the situation. If the conductivity exceeds the limit, it cannot be reused. Whether to add trisodium phosphate depends on the boiler water parameters, not the feedwater parameters. Whether to add ammonia depends on the feedwater pH value. Interestingly, the pH of a lot of steam condensate is >8.
The operating pressure of my boiler is negative; the absolute pressure is 0.7 Bar(a), which is equivalent to -0.3 Bar(g)
I hope this helps: It’s the steam pressure at the boiler outlet that matters, not the air pressure inside the furnace. Check the boiler’s nameplate to find out the rated evaporation rate and the rated outlet steam pressure. (Vapor with a negative pressure at the outlet doesn’t belong to boilers, right? I’ve only seen low-temperature concentrators use negative pressure to lower the boiling point and thus evaporate the material; industrial boilers, on the other hand, operate under pressure.)