How does flue gas temperature affect the operation of wet electrostatic precipitator flue gas?
Publish Time: 2024-12-04
Flue gas temperature is a critical parameter in the operation of wet electrostatic precipitator flue gas, and it has a significant impact on the operation effect in many aspects.
When the flue gas temperature is high, it will first affect the volume flow of the flue gas. According to the ideal gas state equation, as the temperature rises, the flue gas volume expands, and the flow rate inside the wet electrostatic precipitator flue gas will increase. This may shorten the residence time of the flue gas in the electric field, reduce the contact opportunities between particulate matter and pollutants and electrodes and spray droplets, and thus reduce the dust removal and pollutant removal efficiency. For example, the high-temperature flue gas generated by some industrial kilns directly enters the wet electrostatic precipitator flue gas. If it is not effectively cooled, this may happen.
Secondly, the high-temperature flue gas may cause the spray liquid to evaporate rapidly. On the one hand, this will change the concentration and physical properties of the spray liquid, affecting its ability to absorb and capture pollutants; on the other hand, a large amount of water evaporation may lead to increased electrode scaling, because soluble salts and other substances in the water will precipitate and adhere to the electrode surface. After the electrode is scaled, the electric field strength is unevenly distributed, the discharge performance is reduced, and the dust removal and purification effects are further weakened, the equipment operation resistance is increased, and even equipment failure may occur.
When the flue gas temperature is too low, below the acid dew point temperature, the acidic gases in the flue gas, such as sulfur dioxide, will combine with water vapor to form acid mist or condensed acid liquid. These acidic substances will corrode the metal parts of the wet electrostatic precipitator flue gas, including the shell, plate, pole wire, etc., reducing the service life and reliability of the equipment. At the same time, the droplets produced by condensation may combine with particulate matter to form a more viscous substance, which is not easy to be removed, causing blockage of the plate and pole wire, affecting the normal operation of the electric field, reducing the dust removal efficiency, and may also increase the cleaning and maintenance costs of the equipment.
Therefore, during the design and operation of the wet electrostatic precipitator flue gas, the flue gas temperature must be strictly monitored and controlled. The high-temperature flue gas can be cooled to a suitable range by setting up flue gas cooling devices, such as waste heat boilers and heat exchangers; for low-temperature flue gas containing acidic gases, heating or insulation measures can be used to prevent acid dew point corrosion and condensation, thereby ensuring that the wet electrostatic precipitator flue gas can operate stably and efficiently, achieve good flue gas purification effects, meet environmental emission requirements, and ensure long-term stable operation of the equipment.
