oxygen enrichment rate setting method and the blast furnace operation method

摘要

PROBLEM TO BE SOLVED: To provide a method of setting an oxygen enrichment rate which can improve combustibility of powdered coal when hot air blown into a tuyere is enriched with oxygen and powdered coal and oxygen are blown into the tuyere.;SOLUTION: A ratio of enriched oxygen in hot air to enriched oxygen blown from the vicinity of powdered coal, i.e. a tuyere blow oxygen ratio, is adjusted on the basis of a combustion state at the tip of the tuyere. Because the combustion state at the tip of the tuyere changes in response to a tuyere blow oxygen ratio, preliminary grasping of the relationship between the tuyere blow oxygen ratio and the combustion state at the tip of the tuyere enables determining an optimal value of the tuyere blow oxygen ratio for achieving a good combustion state at the tip of the tuyere. The relationship between tuyere blow oxygen ratio and the combustion state at the tip of the tuyere also depends upon the amount of blown powdered coal per unit pig iron, i.e. the powdered coal ratio. Preliminary determination of the relationship between tuyere blow oxygen ratio and the combustion state at the tip of the tuyere for every powdered coal ratio, therefore, enables determining an optimal value for achieving good combustion state even when the powdered coal ratio varies.;COPYRIGHT: (C)2014,JPO&INPIT