Development Of Directional Low NOx Special Burner For Delayed Coking

With the development of double side radiant delayed coking furnace, the flat flame burner has come into wide application. After analysis of the characters and the existing problems of the current burners, the special wall-burner for the delayed coking was designed and the influence of different parameters on the combustion conditions are studied. In the research operational parameters and structural parameters of several kinds of refinery burners were compared and analyzed. The calculating method to design the burners were determined according to the basic combustion theory and the adiabatic expansion theory before the new model of burner was designed which adopted low NOx combustion technology. Also multi-suits of new small-powered burner and large-powered burner were designed and produced.The combustion experiments reveal that the major parameters that influence the performance of burner are the operational parameters and the structural parameters, of which the former mainly includes the flux of the fuel gas, pressure and the fuel gas-to-air flux ratio and so on, and the latter mainly includes the structure of the firebrick, the nozzle diameter, nozzle obliguity and space between the nozzles. In the experiments influence of different manners of air provision, flow rates and pressures on combustion conditions were investigated and the results show combustion performance under forced ventilation is superior to that under natural ventilation; both of the flow rates and loads of the combustion gas increase with the pressure increasing, and the burner work normally with flames of good shape when the nozzle rate is 120-240m/s. And combustion with different structures reveal that by changing the structures of the burners we can optimize the shape of the flame and intensify the combustion process. As a result, in the design of the burner firebricks must correspond to the height and space of the spray-guns, the throat and the rotary orifice of the firebrick must correspond to the nozzle angle on the spray gun and at last multi-nozzles and small diameters of the nozzle should be adopted.After practical application, the special burner mentioned above have virtues such as stable combustion, availability to burn attach the wall, no space in the flame, fan-like shape, strong vertical flame with low height.