Blow pipe structure

Abstract

Provided is a blow-pipe structure for a blast furnace facility configured so as to be capable of suppressing slag adhesion by using a simple structure, even if pulverized coal with an unadjusted softening temperature is used. The blow-pipe structure is attached to a tuyere for a blast furnace main body that produces pig iron from iron ore, said blow-pipe structure injecting auxiliary fuel pulverized coal together with hot air, and slag from the pulverized coal containing a component that is melted by the hot air and/or heat from combustion of the pulverized coal. A resisting element that increases flowpath resistance on the pipe inside wall surface side and concentrates the flows of the hot air and the pulverized coal to the flowpath axis center is provided on the downstream side of an injection lance that inserts pulverized coal into the blow pipe.

1 . A blow-pipe structure attached to a tuyere of a blast furnace main body for producing pig iron from iron ore, the blow-pipe structure injecting pulverized coal as an auxiliary fuel together with hot air, and slag from the pulverized coal containing a component that is melted by the hot air and/or heat from combustion of the pulverized coal, the blow-pipe structure comprising:
 a resisting element provided on a downstream side of an injection lance for introducing the pulverized coal into a blow pipe, the resisting element increasing flowpath resistance on a side of a pipe inner wall and concentrating a flow of the hot air and pulverized coal to a flowpath axis center.   
     
     
         2 . The blow-pipe structure according to  claim 1 , wherein the resisting element is a plurality of block elements projecting from the inner wall; and
 the block elements project further toward the flowpath axis center than an outlet port of the tuyere and are disposed so as to collectively cover an entire circumference of the pipe inner wall as viewed from the outlet port.   
     
     
         3 . The blow-pipe structure according to  claim 1 , wherein the resisting element is one or a plurality of ring forming block elements projecting from around the entire circumference of the inner wall; and
 the ring forming block elements project further toward the flowpath axis center than the outlet port of the tuyere.   
     
     
         4 . The blow-pipe structure according to  claim 2 , wherein the block element and the ring forming block elements are provided on an upstream side with a slanted surface for gradually decreasing a cross-sectional area of the flowpath. 
     
     
         5 . The blow-pipe structure according to  claim 2 , wherein the block element and the ring forming block elements include a mechanism for varying a level of projection toward the flowpath axis center. 
     
     
         6 . The blow-pipe structure according to  claim 3 , wherein the block element and the ring forming block elements are provided on an upstream side with a slanted surface for gradually decreasing a cross-sectional area of the flowpath. 
     
     
         7 . The blow-pipe structure according to  claim 3 , wherein the block element and the ring forming block elements include a mechanism for varying a level of projection toward the flowpath axis center. 
     
     
         8 . The blow-pipe structure according to  claim 4 , wherein the block element and the ring forming block elements include a mechanism for varying a level of projection toward the flowpath axis center.