Flow Field Characteristic of Postcombustion Oxygen Lance Formed by Various Secondary Nozzle Arrangements

The postcombustion oxygen lance was designed to increase the scrap ratio by consuming CO in the flue gas. In this research, three secondary nozzle arrangements were designed to investigate the combustion efficiency between the secondary oxygen jet and CO. Moreover, both numerical simulation and experimental tests were carried out to analyze the flow field of the main and secondary oxygen jets, and their axial velocity profiles were experimentally measured to verify the reliability of simulation data. The result showed that the postcombustion lance obviously extended the combustion flame region at high ambient temperature, compared with the traditional oxygen lance. Unlike the postcombustion lance designed by four secondary nozzles, the secondary oxygen jet formed by the postcombustion lance designed by eight secondary nozzles quickly merged with the main oxygen jet, resulting in the lowest combustion reaction heat among three kinds of postcombustion lances. Besides, the all three kinds of postcombustion lances significantly improved the impaction depth of the main oxygen jet, comparing with the traditional oxygen lance.