A annealing furnace of the solid solution stainless steel pickling and annealing line of a well-known domestic company in Guangxi is equipped with 120 low NOx air staged burners SNLNOx. This annealing furnace have 8 temperature control zones, which adopt double-cross limit flow control method.

The furnace temperature is 1150~1200°C, the air preheating temperature can reach up to 600°C, and the air preheating temperature at the entrance of the burner with the farthest distance from the heat exchanger is above 450°C when producing.

 The components of flue gas in each zone during normal production are as follows:

 The NOx emissions of 8 zones and the NOx emissions of total exhaust pipe at different times are as follows(ref. 8% O2):

 Raising air preheating temperature and strengthening waste heat recovery are the main ways to save energy in industrial furnaces. The air preheating temperature of this annealing furnace can reach up to 600°C, and low NOx emissions can still be achieved, which truly meets the requirements of energy saving and environmental protection.