The QR12x2 direct combustion inner hot gas generator manufactured by Tianlong is the supporting facilities of the 2x180m2 sintering machine desulfurization and denitration upgrading project, a single furnace heating flue gas volume is 1380000Nm3/h, the heating capacity of this furnace is 18x106kcal/h, in March of 2022, successful ignition, all of indicators passed, this furnace has been formally transferred to the user for production.