Convection Tubes Leak

[consilience1]

Dear all

Our plant suffer from the leakage on convection tube in heater. The convection tube is for making saturated steam, and recently chemicals for BFW was changed. So we suspected failure of water chemistry, and try to repair the leaked tube with plugging way because there is no spared tubes.

By the way, we concern about the situation after plugging some convection tubes which are leaked. Definitely the number of tubes are decreased, and it will impacts the amount of steam generated and its qualities. Also, according to decreasing heat absorption to convection tubes, flue gas temperature will be higher.

For that case, is there any some tools for calculation or estimation, for example, if 50% of tubes is plugged, how much steam flow rate is decreased? or how much temperature is increased on tube skin?

Thank you

 

[chicopee]

50% of plugged tubes is too much. If I remember correctly 10% of tubes according to an insurance boiler inspector said is the max. before retubing. You did not specify where the tube leaks are developing from nor the type of boiler. That could shed some light as to the cause. Talk to your insurance boiler inspector. Also the National Board of Fired and Unfired pressure vessels has excellent articles on boiler failures.