Bustle pipe arrangement

1. Bustle pipe arrangement of a shaft furnace comprising:

a circumferential bustle pipe arranged along an outer casing of said shaft furnace, said bustle pipe being arranged at a certain distance from said outer casing;

a plurality of first arms connecting said bustle pipe to said outer casing of said shaft furnace on a first level; first blow channels being arranged through said first arms for fluidly connecting said bustle pipe to an interior of said shaft furnace; and

a plurality of second arms connecting said bustle pipe to said outer casing of said shaft furnace on a second level; second blow channels being arranged through said second arms for fluidly connecting said bustle pipe to the interior of said shaft furnace, said first level being different from said second level,

wherein said bustle pipe comprises access ports located in wall portions of the bustle pipe and opposite to said first and/or second blow channels, in linear alignment with respective first and/or second blow channels, and

wherein said first arms are essentially horizontal and wherein said second arms are inclined at an angle of between 10 and 60° with respect to the horizontal.

2. Bustle pipe arrangement according to claim 1 , wherein said first and second arms are configured to support said circumferential bustle pipe.

3. Bustle pipe arrangement according to claim 1 , wherein said bustle pipe comprises a refractory lining on an inner wall and wherein said first and/or second blow channels extend through said refractory lining of said bustle pipe.

4. Bustle pipe arrangement according to claim 1 , wherein a plunger is associated with an access port for at least partially plugging at least one of said first blow channels and second blow channels.

5. Bustle pipe arrangement according to claim 4 , wherein said plunger has a conical nose for allowing regulation of gas flow through at least one of said first blow channels and second blow channels.

6. Bustle pipe arrangement according to claim 1 , wherein an injection nozzle and/or an injection nozzle insert is removably arranged in at least one of the first blow channels and the second blow channels.

7. Bustle pipe arrangement according to claim 1 , wherein said second arms are arranged so as to be, on a vertical projection, arranged half-way between two neighboring first arms.

8. Bustle pipe arrangement according to claim 1 , wherein said first and/or second arms are formed by a straight piece of piping lined internally with refractory material and having said first and second blow channels passing therethrough.

9. Bustle pipe arrangement according to claim 1 , wherein said second arms are arranged at an angle chosen such that access ports associated with said second blow channels are essentially on the same level as access ports associated with said first blow channels.

10. Bustle pipe arrangement according to claim 1 , wherein said first and second support arms are both inclined at an angle of between 0 and 40° with respect to the horizontal.

11. Bustle pipe arrangement according to claim 1 , further comprising at least one plurality of auxiliary arms connecting said bustle pipe to said outer casing of said shaft furnace, wherein auxiliary blow channels are arranged through said auxiliary arms for fluidly connecting said bustle pipe to the interior of said shaft furnace.

12. Bustle pipe arrangement according to claim 1 , wherein said bustle pipe has an essentially round or oval cross-section.

13. Bustle pipe arrangement according to claim 4 , wherein said plunger comprises an oxid-ceramic material or a silicon infiltrated silicon carbide material.