Analysis of the leakage causes at the tube elbows of the economizer in circulating fluidized bed boilers
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Over the past year, the final elbow of the economizer in the 3*45 tons/hour circulating fluidized bed saturated steam boiler has been leaking frequently; the pH level of the boiler water during these leaks was always low, below 6.5. What could be the reason? Is it related to the boiler feedwater? The pH of the boiler feedwater control can sometimes drop below 7. Is the recent replacement of the economizer tubes from 32*3 to 32*4 related to the reduction in the inner diameter of the pipes? Manager Discussion Group
What is the form of the leakage? Corrosion on the water side or on the flue gas side? I think the main issue is the pH value; diameter changes are something that occurs frequently and do not directly cause the phenomenon you mentioned~
It may be caused by a low pH level over a long period of time.
The boiler is filled with desalinated water + 90-degree hot water. If ammonia is not added to the deionized water, its pH is around 6; the pH is mainly adjusted by adding ammonia. Is it related to the fact that ammonia is not added in a timely manner to the desalinated water? 90-degree hot water is steam condensate, with a pH of generally 8-9
It is not a problem related to elbow diameter changes; the pH value is acidic, indicating that it is caused by corrosion on the inner wall of the water pipe.
It’s our deaerator that has a problem; the oxygen level in the boiler is quite high