Backflow of boiler flue gas into the induced draft fan of an adjacent boiler
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Our company’s boilers operate in a one-in-use and one-backup mode, sharing the desulfurization unit and chimney. The following issue occurred during operation: the flue gas from the boiler in use flowed back into the flues and exhaust fans of the standby boiler, and the condensed wet flue gas caused severe corrosion to the exhaust fans and flues. Initially, the flue gas was kept out by replacing the backup furnace air plates; after some time, the wet flue gas corroded the partitions and seeped back in. There is no good solution at the moment; I hope those with more experience can offer some guidance.
Is there sealed air in the middle of the baffle door?
It seems to be a single-layer louver-style air flap. Do you mean the sealing air as the air that flows between the double-layer air panels? So does that mean a fan needs to be running continuously? Also, it’s not good for the fan to maintain pressure over a long period without any air intake. (Our primary fan is located quite far away.)
I’m not sure either if this is the right approach, but to ensure 100% airtightness, it’s necessary to fill the space between the double-layer dampers with sealed air. The air volume is not high, but the wind pressure is high; it can operate for long periods without issues. It usually refers to small centrifugal fans with a capacity of just a few kilowatts
Well, it seems the air exchange panel needs to be replaced. Planning to replace it with double-layer air flaps, with sealed air flowing in between. Considering bringing in primary air would also save on heating costs; I’m not sure if that’s feasible.