Thermal NOx formation is very high in the rotary cement kiln due to high-temperature flame. Essentially all NOx emissions associated to the cement manufacturing are formed in cement kilns. In this paper, the effects of natural gas injection into calciner exhaust, i.e., rotary kiln inlet, on NOx reburning by CO and CH radicals is numerically and experimentally investigated. A 3D model of turbulent combustion flow to stimulate the NO_X reburning on an industrial scale is developed by the finite volume method. The results show that the NOx reduction can be reached 30 % and 70 % by 950 m³/h and 2750 m³/h natural gas injection, respectively. Furthermore, by increasing natural gas injection flow rate and reaction time, NOx reduction rate is abruptly decreased. The experimental results imply 65 % NOx reduction by natural gas injection from walls of rotary furnace channel inlet where good agreement by numerical results is well proved. Obtaining results also prove that the NOx return in swirling region is highly increased and NOx concentration remarkably reduced.

由于高温火焰，旋转水泥窑中的热NOx形成非常高。基本上所有与水泥生产相关的NOx排放都在水泥窑中形成。本文通过数值和实验研究了天然气注入煅烧炉排气（即回转窑入口）对CO和CH自由基再燃NOx的影响。通过有限体积法建立了湍流燃烧流的3D模型，以刺激工业规模的NO _X再燃烧。结果表明，在950 m ³ / h和2750 m ^3下，NOx的还原率分别达到30％和70％。/ h分别注入天然气。此外，通过增加天然气注入流量和反应时间，NO x还原率急剧降低。实验结果表明，从旋转炉通道入口的壁中注入天然气可减少65％的NOx，数值结果已很好地证明了这一点。所得结果还证明，在旋流区域中的NOx返回高度增加并且NOx浓度显着降低。