PURPOSE: To prevent the occurrence of explosion by the backflowing reducing gas from a reducing furnace at the suspension of burner combustion by connecting inert gas pipings between the burners of the nonoxidation furnace and the control valves of the air pipings for combustion.
CONSTITUTION: With a nonoxidation furnace 1 of continuous Zn or continuous Al plating equipment or continuous silicon steel plate bright annealing equipment, gas pipings 6 for combustion and air pipings 9 for combustion are connected to burners 2. In addition, inert gas pipings 12 are connected between the burners 2 and the control valves 11 of the air pipings 9. When the combustion of the burners 2 is interrupted by closing the air control valves 11, there is possibility that the reducing gas contg. H2 supplied into the reducing furnace 4 behind these flows into the nonoxidation furnace 1 via the heating furnace 3 and explodes in the air pipings 9. At this time, an inert gas is sent into the nonoxidation furnace by opening control valves 13 to prevent the occurrence of explosion by the air remained in the air piping 9.
ISHIDA RIYOUICHI
MATSUMURA ICHIROU
NISSHIN STEEL CO LTD