Which burners can be classified according to the principle of low nitrogen combustion transformation

Which burners can be classified according to the principle of low nitrogen combustion transformation?
1) Stage burner:
A stage burner designed based on the principle of staged combustion, which mixes fuel and air in stages for combustion, can reduce the generation of nitrogen due to combustion deviation from the theoretical equivalence ratio.
2) Self recirculation burner:
One method is to use the pressure head of combustion air to suck back some of the combustion flue gas, enter the burner, and mix with the air for combustion. Due to flue gas recirculation, the thermal capacity of the combustion flue gas is large, the combustion temperature decreases, and NOx decreases, which is known as the flue gas external circulation. Another type of self recirculation burner is to directly recirculate some flue gas into the burner and add it to the combustion process. This type of burner has a dual effect of suppressing nitrogen oxide and saving energy, that is, flue gas internal circulation.
3) Thick and thin burner:
The principle is to cause one part of the fuel to be burned too rich and the other part to be burned too lean, but the overall air volume remains unchanged. Due to the combustion of both parts deviating from the chemical equivalence ratio, NOx is very low, and this type of combustion is also known as deviating combustion or non chemical equivalence combustion.
4) Split flame burner:
The principle is to divide a flame into several small flames. Due to the large heat dissipation area of the small flames and the lower flame temperature, the "thermal reaction NO" decreases. In addition, a small flame shortens the residence time of gases such as oxygen and nitrogen in the flame, and has a significant inhibitory effect on both "thermal reaction NO" and "fuel NO".
5) Blending promoting burner:
The residence time of flue gas in the high-temperature zone is one of the main factors affecting the generation of NOx. Improving the mixing of combustion and air can reduce the thickness of the flame surface. Under the same combustion load, the residence time of flue gas in the flame surface, i.e. in the high-temperature zone, is shortened, thus reducing the generation of NOx. The mixed promotion burner is designed according to this principle.