White Elimination Technology for Flue Gas Treatment
Causes of colored smoke plume
After adding the wet desulfurization plant, the flue gas becomes saturated wet flue gas. When this kind of flue gas comes into contact with the ambient air at a lower temperature, the water vapor contained in the flue gas condenses into liquid, and the condensed water droplets refract and scatter the light, thus showing the white smoke from the stack. With the further diffusion of flue gas in the atmosphere, condensed droplets evaporate again, and white smoke gradually disappears.
The smoke plume can be eliminated mainly from two aspects: reducing the absolute and relative moisture content of flue gas.
1. With the wet flue gas condensation, dehumidification and reheating technology, the saturated moisture content of wet flue gas can be reduced from 111.8 g/Nm3 to less than 50 g/Nm3, close to the atmospheric moisture content;
2. By recycling the condensate of wet flue gas, the moisture content of flue gas can be reduced by more than 0.8 tons per ton of coal burnt. The recycled condensate can be used as supplemental water for desulfurization or boiler after appropriate treatment;
3. The purpose of condensing and dehumidifying is to condense most of the remaining fine particle dust, sulfur dioxide, acid, heavy metals, and other pollutants into the drainage, so as to realize ultra-low near zero emission;
4. After dehumidification, the moisture content in the flue gas is reduced, so that the heat required for reheating the flue gas is reduced, and a good white elimination effect can be achieved without the need of re-heating the flue gas to 80℃;
5. Polytetrafluoroethylene (PTFE) is used as raw material for heat exchanger manufacturing:
（1）It has excellent corrosion resistance performance;
（2）The heat exchange tubes have smooth surfaces, no dust, and scale accumulation, and are easy to clean;
（3）The tube wall is thin, with good heat exchange performance. The volume is 1/4 of that of the metal tube heat exchanger;
（4）Durable and flexible with high fatigue strength;
（5）It has good temperature and pressure resistance performance and can run well in various strongly corrosive media below 200 ℃;
（6）The supporting structural members are all carbon steel lined with fluoroplastics and the connecting bolts are made of C276 alloy to avoid material corrosion.
（7）The online flushing system can be realized.