Dew point temperature of flue gas at the outlet of the desulfurization tower
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I would like to ask the experts: what is the dew point temperature of the flue gas at the outlet of the desulfurization tower after desulfurization?
The last edit to this post was made by zfc318 on 2010-11-19 at 17:10. Looking at the components of the smoke, it mainly consists of acidic gases such as sulfur trioxide and nitrogen dioxide
It’s usually around 80°, but it varies
1. The main component of sulfides in flue gas is SO2, not SO3. S first reacts with O2 to form SO2; SO2 then reacts to produce SO3 only at temperatures above 400°C in the presence of V2O5 as a catalyst. The chemical conditions required for the formation of SO3 are extremely stringent, so there is almost no SO3 present in flue gas. 2. Specifically and accurately, this has to be determined based on the composition of the flue gases after gas combustion! Dew point corrosion of flue gas mainly refers to sulfur corrosion, which is related to temperature T; when 120°C < T < 240°C, active sulfur remains undecomposed and no corrosion occurs. Since the furnace temperature in typical refining and petrochemical heating furnaces is certainly above 240°C, active sulfur must decompose and generate SO2 through combustion reactions. According to industry experience, the temperature of flue gases emitted from chimneys should generally be kept above 135°C; in winter, it should be maintained above 145°C due to natural climate changes. But it’s certain that the figure of 135°C has been mentioned in many books! It still has reference value!
The desulfurization tower uses a wet desulfurization process; the temperature of the flue gas at the inlet is around 130 degrees. After passing through the spray nozzles inside the tower, the temperature at the outlet does not reach the values mentioned above
Hehe! If there is no GGH at the outlet of wet flue gas desulfurization, the flue gas temperature is usually below the acid dew point; that’s why corrosion protection needs to be considered!
The flue gas temperature at the outlet of wet flue gas desulfurization is always below the dew point temperature; even with GGHs, corrosion issues cannot be avoided, as the flue gas temperature at the outlet of GGHs is usually only around 80 degrees Celsius. Therefore, anti-corrosion measures are necessary for the ductwork in the latter stages of wet flue gas desulfurization.