Improvement of Reducing Flame Burner with Oxygen Enrichment

Recently, in the non-oxidizing furnace (NOF) of the continuous annealing process, steel sheet is heated by reducing and direct fired heating with reducing-flame burner instead of by the radiant tube heating. Firstly we investigated the reductive performance of the burner, and tried to improve the reductive efficiency with preheated and oxygen enriched combustion air. Secondly we attempted to specify the main reductive species by numerical simulation of the laminar coke oven gas (COG) pre-mixed flame. The conclusions are summarized as follows. The oxidized layer on a steel sheet of several mircrons thickness, could be reduced in ten seconds when steel sheet was heated from room temperature to 800°C in a furnace. The reducing flame burner with oxygen enriched combustion air could lead to 1200°C non-oxidizing heating in the open air. As a result of computation, the concentration of H, which is the reductive radical in the reducing flame, was increased by using high temperature flame.