Abstract: There are many types of burners used in tube heaters. Due to the differences in burner structure and mechanism of combustion, the formation of NO_x could be different during the combustion. For the heaters that have not been replaced with low NO_x burners in time for some reasons, if the burner is replaced by shutting down the device to meet the environmental protection emission requirements, it will affect the normal production operation. Then the burner can be revamped online, adopting low NO_x combustion mechanism to change the fuel combustion mode to reduce the flue gas NO_x content. The online revamp of the burner should consider such factors as single heat load, fuel gas properties, air supply, temperature, height of the furnace, and the distance between the furnace tube and the burner and so forth. This paper introduces this technology by taking the online revamp of a 2 Mt/a residue hydrogenation unit with low NO_x burner as an example. The data after the revamp indicates that the revamp has achieved good results.

Key words: low-NO_x burner, heater, revamp, combustion condition