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High temp. Ash corrosion

My question is about High temperature ash corrosion. Our boiler produces refuse and uses fuel oil # 4 but I need to know how to control that corrosion--what pH control to have in refuse or condensed form flue gases, at level of air preheater. Now we have pH around 1,9-2,6 in refuse recovery each 24 hours. I appreciate your information.

Thank you,

Gustavo Gabaldón
combustion engineering - Esmeraldas, Ecuador
2004

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Dear Sir

Actual mechanism of Corrosion in Air Pre Heater is due to low incoming air temperature. If we are feeding cold air inside the air preheater, then Skin Temperature at the inlet of Air Pre heater goes down considerably below 100 °C due to which Corrosion takes place.

Normally pH greater then 3 is required in order to reduce any corrosion because above this pH Corrosion rate normally remains constant. It is also advisable to heat incoming air which is fed inside the air pre heater.

Regards

Jagdish

Jagdish Bhadra
- Mumbai, Maharastra, India
2004