Oxygen corrosion of boilers
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Boiler feed water usually needs to be deoxygenated to prevent oxygen-induced corrosion in the boiler; this deoxygenation is generally carried out by heating with steam in a deaerator. My question is: how does the deaerator itself prevent oxygen-induced corrosion? Is it an anti-corrosion coating, an improvement to the material of the equipment, or some other chemical method? Please give me some advice!
Generally, there seems to be no control over the oxygen corrosion of the deaerator itself; the deoxidizer is also added to the water tank of the deaerator. Adjusting the pH of the make-up water to around 9.5 is beneficial for the deaerator
The deaerator does not appear to have any anti-corrosion lining; its material is usually 16MnR. Inspections of the interior of the deaerator revealed numerous pitting defects on its surface. This is generally done by maintaining an alkaline environment to prevent oxygen-induced corrosion.
If deaerators don’t corrode at all, then why is deaeration necessary?
Let’s see who has any good ideas to solve it
During design, only a corrosion allowance is considered for the deaerator itself. But most of the internal components of the deaerator are made of stainless steel, such as stainless steel wire mesh.
This poster has creative ideas and takes an alternative approach; thumbs up
Logically, the oxygen corrosion environment in the deaerator should be the most severe.
Although the oxygen content in the deaerator is higher than that in the boiler, the operating temperatures and pressures of the boiler and the deaerator differ significantly. At the operating pressure and temperature of the boiler, oxygen corrosion is relatively severe, whereas the deaerator operates under conditions of lower pressure and temperature.