Patent ID: 6090181
Filing Date: 2000-07-18
Classification: C21B

Abstract:
A method of operating a blast furnace for manufacturing pig iron in which a carbon reducing agent and ores are charged therein from a furnace top, said furnace including a plurality of tuyeres disposed vertically below said top, thereby defining a tuyere level, comprising the steps of:selectively pre-packing a core section of the furnace with a plurality of solid high density carbonaceous blocks to form a conically-shaped dead man zone prior to an ignition of said furnace, said ignition representing a start of an operating condition of said furnace;mixing said ore and carbon reducing agent and then charging said mixture into said furnace on a periodic basis during operation;starting operation of said furnace by igniting said carbon reducing agent with a continuous blast of hot air;continuously injecting pulverized coal into said furnace through at least one of said tuyeres during operation of said furnace;continuously monitoring a pressure within the furnace between said furnace core and said furnace top in order to formulate a base furnace differential pressure;monitoring a shape of said dead man zone during operation;periodically replenishing said dead man zone by charging additional high density blocks into said furnace through said furnace top when said pre-packed blocks of said dead man zone reach said tuyere level;monitoring a position of said replenished blocks immediately after they are charged;evaluating said pressure measurements and said position of said replenished blocks in order to one of, add additional blocks when said differential pressure is low relative to a base differential pressure, and delay charging additional blocks if said pressure is high relative to said base differential pressure.