Low NOx burners, also known as low nitrogen oxides burners, can significantly reduce the nitrous oxide emissions in the combustion process. NOx in the flue gas is produced in the combustion process, and different combustion methods or conditions have great impacts on the formation of NOx. Therefore, NOx can be reduced by improving the combustion technology.
Positively responding to the national energy saving and emission control policy, SMDERI has built a low NOx combustion test platform and actively explored in the development of low NOx technology. Now SMDERI has developed a series of new low-NOx burners and achieved good results through the cooperation with many petrochemical enterprises.
◇ Multi-stage combustion & air supply to split the flame evenly and establish
the uniform high temperature zone;
◇ Flue gas will form an forced back-flow around burner, so as to stabilize the
flame root and decrease concentration;
◇ The distinctive technology, design and product structure realizes the minimized NOx emission;
◇ Applications: Various types of heater, big steam boiler and fuel boiler, etc.
◇ NOx emission: Less than 60mg/m3
Less than 30mg/m3
◇ CO concentration: less than 40ppm
#3 Boiler at the company is equipped with 6 units of burners. The burners were arranged at two levels with the elevation of 6m and 8.2m, where 3 units were installed at each level and with the space of 2m each other. The burners were originally fueled by oil & gas, which need to be changed as gas-fueled to meet the demand of environmental protection.
SMDERI developed and supplied 6 units of 20MW Low NOx Burner, which is fueled by mixed fuel gas and with load of 30%-120% adjustable. The burners are arranged at the front wall of the boiler to replace the old oil & gas burners. The existing fuel pipeline and air distribution pipeline are maximally utilized as well.The new type of low NOx burner uses staged combustion to split flame, adopts the flue gas recirculation to lower down the temperature of high temperature flame zone, draws part of the flue gas before chimney back to the outlet of blower to decrease the oxygen containing in the burning air and lower down the average temperature of the combustion zone, so that the temperature inside the chamber is evenly at around 1200-1300℃ and there is no significant high temperature zone. Finally the NOx is restrained effectively.
In this project, SMDERI supplied 12 units of low NOx burner for the Heater at Sinopec Shanghai Petrochemical Corp. to meet up the demand of energy saving & emission reduction.
Based on the flue gas internal circulation design, the burner makes the high temperature flue gas back-flow near the burner outlet and mix with air so as to decrease oxygen concentration, prolong the combustion velocity and finally decrease the NOx emission.
After completion, the NOx concentration emission is less than 60mg/Nm3.