US 5,333,840 AGranted

Blast pipe and tuyere arrangement for a blast furnace and method

AssigneeSSAB Tunnpl.ang.t AB

InventorsBror E. Skold, Nils O. Lindfors, Jan O. Wikstrom

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Abstract

Fuel and combustion gas are supplied to the blast pipes and tuyeres of a blast furnace through injection lances which have an inner tube and an outer tube. The inner tube is generally used to carry the fuel, while the space formed between the inner and outer tubes is used to carry the combustion gas. Such a lance can have a heat resistant tip which has a bore for forming an extension of the inner fuel supply tube, and which also has a number of helical channels disposed about the bore for forming an extension of the space between the tubes. It is advantageous to have more than one such lance in each blast pipe and to have the lances extend obliquely into the hot blast channel that is formed by the blast pipe and the tuyere.

Claims27

Dependent claims

In a blast furnace, an injection arrangement for injecting at least fuel and gas into the blast furnace, the blast furnace having an exterior wall, the arrangement comprising:

a blast pipe;
a tuyere disposed at a first end of the blast pipe;
the blast pipe and tuyere forming a blast pipe-tuyere arrangement;
the blast pipe-tuyere arrangement defining a first passage therewithin, and the blast pipe-tuyere arrangement being disposed through the exterior wall of the blast furnace for carrying at least hot air into the blast furnace;
lance means for injecting fuel into the first passage of the blast pipe-tuyere arrangement, said lance means having a first end disposed within said first passage;
and
said lance means comprising:
an outer tube and an inner tube, the inner tube being disposed within the outer tube;
said inner and outer tubes defining a second passage between said inner and outer tubes, said second passage for conducting a gas into said first passage, the gas being for enhancing combustion in the blast furnace;
said inner tube defining a third passage therewithin, said third passage for conducting fuel into said first passage;
tip means disposed at said first end of said lance means;
and
said tip means comprising:
a longitudinal bore therethrough, said longitudinal bore being disposed to provide a continuation of said third passage;
and
a plurality of helical passages separated from and disposed helically about said longitudinal bore, said helical passages being disposed to provide a continuation of said second passage.

13 more elements

Lance means for injecting fuel and gas into a first passage of a blast pipe-tuyere arrangement of a blast furnace, the gas being for enhancing combustion of the fuel, said lance means having a first end disposed within the first passage, said lance means comprising:

an outer tube and an inner tube, the inner tube being disposed within the outer tube;
said inner and outer tubes defining a second passage between said inner and outer tubes, said second passage for conducting the gas into said first passage;
said inner tube defining a third passage therewithin, said third passage for conducting the fuel into said first passage;
tip means disposed at said first end of said lance means;
and
said tip means comprising:
a longitudinal bore therethrough, said longitudinal bore being disposed to provide a continuation of said third passage;
and
a plurality of helical passages separated from and disposed helically about said longitudinal bore, said helical passages being disposed to provide a continuation of said second passage.

6 more elements

A method for injecting fuel and gas into a blast pipe-tuyere arrangement of a blast furnace, the blast pipe-tuyere arrangement defining a first passage therethrough, and the blast pipe-tuyere arrangement comprising lance means for injecting the fuel and gas into the first passage, said lance means having a first end disposed within the first passage, and said lance means comprising:

an outer tube and an inner tube, the inner tube being disposed within the outer tube;
said inner and outer tubes defining a second passage between said inner and outer tubes, said second passage being configured for conducting the gas into said first passage, the gas being for enhancing combustion of the fuel;
said inner tube defining a third passage therewithin, said third passage being configured for conducting the fuel into said first passage;
tip means disposed at the first end of said lance means, said tip means comprising:
a longitudinal bore therethrough, said longitudinal bore being disposed to provide a continuation of said third passage;
and a plurality of helical passages separated from and disposed helically about said longitudinal bore, said helical passages being disposed to provide a continuation of said second passage;
and said method comprising the steps of:
providing said inner and outer tubes of said lance means;
configuring said inner and outer tubes to define said second passage between said inner and outer tubes and said third passage within said inner tube;
disposing said tip means at the first end of said lance means;
providing said longitudinal bore through said tip means;
providing said plurality of helical passages in said tip means helically about said longitudinal bore;
passing the fuel through the third passage of the inner tube;
passing the fuel through the longitudinal passage of the tip means;
passing the gas through the second passage between the inner and outer tubes;
passing the gas through the plurality of helical passages of the tip means;
inducing a swirling motion to the gas by passing the gas through the helical passages;
expelling the gas out of the helical passages in a swirling motion;
and
expelling the fuel out of the longitudinal passage into the swirling gas.

17 more elements

an outer tube and an inner tube, the inner tube being disposed within the outer tube;
said inner and outer tubes defining a second passage between said inner and outer tubes, said second passage for conducting the gas into said first passage;
said inner tube defining a third passage therewithin, said third passage for conducting the fuel into said first passage;
tip means disposed at said first end of said lance means;
said tip means comprising:
a longitudinal bore therethrough, said longitudinal bore being disposed to provide a continuation of said third passage;
and
a plurality of passages separated from and disposed about said longitudinal bore, said plurality of passages being disposed to provide a continuation of said second passage;
said tip means have a longitudinal axis, said longitudinal bore of said tip means being disposed along the longitudinal axis;
said plurality of passages of said tip means comprise a terminal portion of said second passage, each of said plurality of passages comprising corresponding mouth portions for expelling the gas into said first passage, said mouth portions of said plurality of passages being disposed radially with respect to the longitudinal passage of said tip means to disperse the gas radially away from said tip means.

7 more elements

an outer tube and an inner tube, said inner tube being disposed within said outer tube;
said inner and outer tubes defining a second passage between said inner and outer tubes, said second passage for conducting the gas into said first passage;
said inner tube defining a third passage therewithin, said third passage for conducting the fuel into said first passage;
tip means disposed at said first end of said lance means, said tip means comprising:
a longitudinal bore therethrough, said longitudinal bore being disposed to provide a continuation of said third passage;
and
a plurality of passages separated from and disposed about said longitudinal bore, said plurality of passages being disposed to provide a continuation of said second passage;
each of said plurality of passages comprising a terminal portion of said second passage, each of said plurality of passages comprising corresponding mouth portions for expelling the gas into said first passage;
and
said lance means comprising means for adjusting a size of at least one of said mouth portions of said plurality of passages to adjust dispersion of the gas expelled therefrom.

7 more elements

Dependencies are inferred from the claim text.