The core function of the induced draft fan in a steam boiler is to maintain a slight negative pressure in the furnace, discharge flue gas and overcome flue resistance, ensuring stable combustion, safe operation and compliance with environmental protection standards.
Now, let’s have the editor introduce to you the core function of the induced draft fan.
Maintain a slight negative pressure in the furnace: In coordination with the supply fan, it forms balanced ventilation, keeping the furnace pressure at approximately -40 to -60Pa to prevent the escape of flames and flue gas, while reducing the leakage of cold air, thus avoiding a decline in thermal efficiency and damage to the furnace wall.
2. Exhaust flue gas and overcome resistance: Extract the high-temperature flue gas generated by combustion, overcome the pressure loss in the tail flue, air preheater, dust collector, desulfurization and denitrification device, and chimney, and ensure smooth exhaust of flue gas.
3. Ensure stable and efficient combustion: Stable flue gas exhaust provides continuous oxygen supply conditions for combustion. Combined with the adjustment of air supply volume, the oxygen concentration inside the furnace and combustion conditions are optimized to enhance combustion efficiency and reduce unburned losses.
4. Support for environmental protection compliance with emission standards: Provide stable flue gas flow and pressure head for subsequent environmental protection equipment such as dust removal, desulfurization, and denitrification to ensure that pollutants are discharged up to standard.
5. Adjust load and operating conditions: Regulate air volume through frequency conversion or baffles to match the combustion requirements of the boiler under different loads, stabilize the furnace pressure and flue gas temperature, and ensure the safe and economic operation of the unit.