Classification of low nitrogen burners

The burner is an important piece of equipment for industrial furnaces. It ensures stable ignition and combustion of the fuel and complete combustion of the fuel. Therefore, to suppress the generation of NOx, we must start with the burner. According to the combustion technology that reduces NOx, oxide low-nitrogen burners are roughly divided into the following categories:
1. Stage burner: The stage burner designed based on the principle of staged combustion allows fuel and air to be mixed and burned in stages. Because the combustion violates the theoretical equivalence ratio, it can reduce the generation of NOx. ​
2. Self-recirculation burner One is to use the pressure head of the combustion air to suck part of the combustion flue gas back into the burner and mix with the air for combustion. Because the flue gas is recirculated, the heat capacity of the combustion flue gas is large, the combustion temperature is lowered, and NOx is reduced. Another type of self-recirculating burner recirculates part of the flue gas directly in the burner and adds it to the combustion process. This type of burner has the dual functions of suppressing nitrogen oxides and saving energy. ​
3. The principle of the rich-lean burner is to make part of the fuel burn too rich and the other part burn too lightly, but the overall air volume remains unchanged. Because both parts burn in violation of the stoichiometric ratio, the NOx is very low. This kind of combustion is also called violation combustion or non-stoichiometric combustion. ​
4. The principle of cutting flame type burner is to divide a flame into several small flames. Because the small flames have a large heat dissipation area and the flame temperature is low, the "thermal response NO" is reduced. In addition, the small flame shortens the residence time of oxygen, nitrogen and other gases in the flame, and has a significant inhibitory effect on "thermal reaction NO" and "fuel NO". ​
5. The residence time of the flue gas in the high-temperature zone of the mixed-promoting burner is one of the main factors affecting the amount of NOx generated. Improving the mixing of combustion and air can reduce the thickness of the flame surface. When the combustion load remains unchanged, the flue gas The residence time in the flame surface, that is, the high temperature zone, is shortened, thus reducing the amount of NOx generated. The mixed promotion burner is designed according to this principle. ​
6. Low NOx pre-combustion chamber burner The pre-combustion chamber is a high-efficiency, low-NOx staged combustion technology developed and researched in my country in the past 10 years. The pre-combustion chamber is generally composed of primary air (or secondary air) and a fuel ejection system. The fuel Rapidly mixed with the primary air, a fuel-rich mixture is formed in the primary combustion zone in the pre-combustion chamber. Due to the lack of oxygen, only part of the fuel is burned. The fuel separates volatile matter in the primary flame zone where oxygen is poor and the flame temperature is low, thus reducing Generation of NOx.www.burners-china.com

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