Factors Affecting The Acid Dew Point Temperature Of Flue Gas From Heating Furnaces And Boilers

The acid dew point temperature of flue gas from heating furnaces and boilers is a very important indicator, which affects the flue gas emission from the furnace and the service life of the equipment. Among the factors affecting the acid dew point temperature of heating furnaces and boilers, sulfur content, excess air coefficient and water vapor concentration in flue gas are three core factors.

1. The sulfur content of fuel is a key factor affecting the acid dew point temperature of flue gas. Generally, the sulfur content in refinery dry gas is higher than that in coal, because refinery dry gas, as a by-product of production, has a more complex composition and contains more impurities. Therefore, if you want to lower the acid dew point temperature, you can choose to use low-sulfur coal as fuel instead of refinery dry gas.

2. The control of the excess air coefficient in the furnace is also one of the factors affecting the acid dew point temperature. The higher the excess air coefficient, the higher the oxygen content in the flue gas, which increases the possibility of SO2 conversion to SO3, and the acid dew point temperature will also increase accordingly. Therefore, on the basis of ensuring full combustion of fuel, reducing the air coefficient in the furnace as much as possible can reduce the generation of SO3, thereby reducing the flue gas acid dew point temperature.

3. The water vapor concentration in the flue gas will also affect the acid dew point temperature. When the water vapor concentration in the flue gas is higher, the chance of producing sulfuric acid will be greater, and the acid dew point temperature will increase accordingly. In addition, factors such as negative pressure in the furnace and flue, uneven temperature distribution in the furnace body, and leakage of the heat exchanger will also affect the flue gas acid dew point temperature.

In the use of heating furnaces and boilers, choosing fuel with low sulfur content, controlling excess air coefficient, reducing water vapor concentration in flue gas, and maintaining normal operation of equipment will all help to reduce the acid dew point temperature, thereby increasing the service life of the equipment and saving energy.