Flue gas temperature after sulfur incinerator
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Has anyone used the flue gas from sulfur treatment units to heat steam? What is the temperature of the flue gas after heat extraction, and is it discharged directly after that?
Typically, the temperature of the flue gas after heat extraction is around 250–300°C, after which it is discharged through the chimney.
Reply to 2# Clauspolunit: Our design is set at 316°C, and in actual operation it remains around 310–330°C. Moreover, the heat exchange area of the exhaust gas heater is also relatively large. Could the reason for this high temperature be that the steam superheater is designed to be a bit small? Active participation
How tall are your chimneys?
Reply to 4# Clauspolunit: Our chimney is 100 meters tall, and the location where our facility is situated is on the Inner Mongolia Plateau. Active participation
Reply to 2# Clauspolunit: I’d like to gently ask the experienced experts – how can temperature and dew point corrosion be determined after heat extraction? Thank you so much
Calculating the dew point of flue gases is rather complicated, but based on experience, keeping the temperature at the chimney outlet above 150°C is usually sufficient to avoid dew point corrosion issues. If we estimate that the temperature drops by 1°C for every 1m increase in the height of the chimney, then for a chimney that is 100m high, a flue gas temperature of around 300°C is somewhat high.
Reply to 7# Clauspolunit: Does the flue gas dew point corrosion we are talking about refer to the metal flues behind the tail furnace? Why is it related to the chimney height? Since the inside of the chimney is made of non-metallic materials, is there any risk of dew point corrosion?
Reply to 8# Sideguard: So-called dew point corrosion occurs when the temperature is below the dew point; therefore, as long as the temperature at the chimney outlet is kept above the dew point, dew point corrosion will not occur. The height of the chimney is related to the exhaust gas temperature.
The temperature of the flue gas from sulfur treatment units generally does not drop too low; it can only increase. The reason for this is as follows: The final heat exchange for the flue gas occurs with the deoxygenated water in the waste heat exchanger. Since the saturated vapor pressure of this deoxygenated water is between 3.3–3.9 MPa, its temperature is usually between 240–252 degrees. Therefore, the temperature of the flue gas after heat exchange cannot be lower than that of the deoxygenated water in the waste heat exchanger. When the heat exchange efficiency of the waste heat boiler is poor, the flue gas is not cooled sufficiently, which can lead to overheating; in severe cases, this may damage the pipes.
For flue gas, dew point corrosion need not be considered; the temperature of the flue gas entering our facility is only 260 degrees.