Safety risks associated with excessive oxygen content in heating furnaces
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The heating furnace of this unit is a cylindrical type. Due to a blower failure, it was switched to natural ventilation some time ago; as a result, the oxygen level reached up to 10% (the normal level is 2–3%). Under these operating conditions, in addition to a decrease in parameters such as thermal efficiency, it was observed that the gas flame did not burn properly and the interior of the furnace became darker. Personally, I think too high an oxygen level can cause the heating furnace to become stuck, but after discussing this with other colleagues, some said it’s unlikely to pose any serious safety risks; it merely results in lower thermal efficiency. Therefore, it is solved here. Thank you
Excess oxygen content: 1. The efficiency will definitely be low, which goes without saying; 2. It also exacerbates the occurrence of corrosion due to low-temperature dew points; 3. It further increases the tendency for high-temperature oxidation of the furnace tubes and other components inside the furnace. As for what you mean by a ‘stuffy furnace’, what is that?
After switching to natural ventilation, the air valves of each burner should be opened wider depending on the combustion condition of the flame. In the situation described by the poster, it is likely that the air valves are not adjusted properly; the valves that control the flame should be opened a bit more, while those that allow air to enter the furnace should be closed down. If the flame remains stable and does not go out, there should be no safety hazards. A dead furnace usually occurs when the flame does not burn completely.
Thank you for your reply, but the furnace interior is darker than normal. What could be the reason?
A high oxygen content is likely due to an excess of air entering the heating furnace, which will certainly reduce its thermal efficiency. It should also be noted that positive pressure may develop inside the furnace, which could require special attention....
It’s the engine shutting down – is it possible for the engine to shut down?
Is the heating furnace gas-fired? Burn oil? Combustion of oil and gas? How many air control valves are there on the burner?
Excess oxygen content is not the cause of stalling. Some types of heating furnaces, such as regenerative air heating furnaces, operate at an oxygen content of over 15%.
The heating furnace of this device is a cylindrical furnace; due to a blower failure, it was switched to natural ventilation some time ago, and the oxygen level reached up to 10%. . . . . . . It’s likely due to excessive natural air intake; the negative pressure in the furnace remains unchanged, causing the combustion to shift backward, which results in the phenomenon of darkness inside the furnace. Solution: Adjust the air intake volume or adjust the exhaust chimney volume.