What is low nitrogen combustion technology(2)
Ii. Recycling of flue gas
thermal oil furnace burner
1. Principle: a part of the flue gas after combustion is extracted from the air preheater and directly fed into the furnace, or it is first fed into the bellows to mix with the hot air and then fed into the furnace, so as to reduce the combustion temperature and oxygen concentration, so as to reduce NOx production;
The recycling rate of flue gas = (the amount of recycled smoke)/(the amount of recycled smoke without recycling) ×100%
2. The effect of the flue gas recycling method on reducing NOx is related to the fuel variety and the recycling rate, and the reduction rate of NOx increases with the increase of the recycling rate.
3. When the recycling rate is 15-25%, the NOx emission concentration of pulverized coal furnace can be reduced by ~ 25%.
4. Generally, the recycling rate is about 10-20%;
5. The higher the combustion temperature (such as liquid slag discharging furnace), the greater the recirculation rate has on the reduction of NOx;
thermal oil furnace burner
The use of flue gas recirculation requires the installation of recirculation fans, flue pipes, etc., which increases the investment and makes the system more complex. Therefore, it is necessary to make a technical and economic comparison.
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