Abstract: As an important equipment in the metallurgical industry,the regenerative heating furnace is mainly used for billet heating. Using the high gas and converter gas as fuel and adopting the periodic reversal combustion method,the burner emits off-gas into the atmosphere during the reversal combustion process. The gas emission rate caused by the reversing action reaches to 3%-7%,causing waste of resources and environmental pollution. In order to save resources,reduce pollution,and solve the problem of gas emission caused by regenerative heating furnaces during combustion reversal,the most direct way of recycling is to sweep the residual gas in public pipes into the furnace for combustion. Now,the 160 t/h regenerative reheating furnace of a steel plant is being modified,and a flue gas purge system is installed on the existing operating platform. The flue gas purge system is to lead all the way from the gas flue gas pipeline for purging.The gas flue gas as the purge gas source is pressurized by the induced draft fan,and the purge pipe is connected with the bottom of the gas reversing valve. By adjusting the original gas reversing program and cooperating with the fast response control valve,the start and stop of the scanning process is carried out. During the purge,the flue gas pressurized in advance in the pipeline is ejected,and the residual gas in the public pipeline is quickly blown into the furnace for combustion,so as to achieve the effect of gas emission reduction.At last,the engineering practice was carried out,and the system furnace temperature,furnace pressure,CO emission reduction effect and economy before and after the transformation were compared. For the renovated heating furnace,a single purge volume is 37.05 Nm~3. According to the single reversal cycle of the heating furnace for 60 s,the annual working time of the heating furnace is calculated based on 330 days and the annual purging volume is 17.606 2 million Nm~3. If the purging efficiency is calculated as 90%,the annual gas emission is 15.854 6 million Nm~3,and the corresponding factory gas price is 0.13 yuan/Nm~3,which can save 2.06 million yuan a year. With the application of the regenerative heating furnace backflushing system,the CO emission reduction rate is as high as 90%.