pressurizing deaerator 1

[pradeep4u]

Dear All
I want to know that why deaerator is pressurized. In my plant it is pressurized to 2.5 kg/cm2. what will happen if we pressurize it to 1.5 kg/cm2. Please give your inputs
Regards
Pradeep

 

[MFJewell]

It probably depends on the feedwater/condensate temperature. Ours are operated at 2.5 PSI, but can operate up to 40 PSI.

 

[Dhurjati Sen]

Hi Pradeep,

Oxygen solubility in water decreases with temperature. So it is better to have a higher boiler feed water / condensate temperature. However, higher temperature would lead to boiling of the boiler feed water / condensate. That would decrease the stripping action of the steam. The de-aerator is operated under some pressure just to increase the boiling point of water at the same time keeping it at a higher temperature.

DHURJATI SEN