Smelting unit for steel production with a tap weight of between 60 t and 350 t

Patent metadata

Field	Value
Publication number	US-2025043370-A1
Application number	US-202218718045-A
Country	US
Kind code	A1
Filing date	Nov 28, 2022
Priority date	Dec 13, 2021
Publication date	Feb 6, 2025
Grant date	—

Abstract

A smelting unit for steel production with a tap weight of between 60 t and 350 t and a method for operating the same are disclosed. By a top lance that moves during operation of the smelting unit and the coordinated injection of process gases by sidewall injectors and the top lance, the undulations in the surface of the molten bath are reduced. As a result, fewer drops detach from the surface of the molten bath and soiling of the upper receptacle and the exhaust manifold is significantly reduced.

First claim

1 .- 17 . (canceled)

18 . A smelting unit ( 1 ) for steel production with a tap weight between 60 t and 350 t, comprising:
a lower furnace ( 2 ),
wherein the lower furnace ( 2 ) is refractory-lined and includes a tapping hole ( 3 ),
wherein a receptacle bottom ( 4 ) of the lower furnace ( 2 ) substantially corresponds to a spherically shaped shell section,
wherein a sphere from which the spherically shaped shell section originates geometrically has a radius≥5 m and ≤15 m, and
wherein a distance (d S ) between a lowest point of the receptacle bottom ( 4 ) in the lower furnace ( 2 ) and a surface ( 6 ) of a melt ( 7 ) located therein in an operating state is ≥0.5 m and ≤1.5 m;
an upper furnace ( 8 ),
wherein the upper furnace ( 8 ) is substantially cylindrical and water-cooled, and
wherein a height (h O ) of the upper furnace ( 8 ) is ≥3 m and a radius (r O ) of the upper furnace ( 8 ) is ≥2 m;
a first cover ( 9 ) closing the upper furnace ( 8 ) at a top, having an exhaust gas nozzle ( 10 ) and at least one opening ( 11 ) for inserting a top lance ( 12 ) into the smelting unit ( 1 )
wherein the top lance ( 12 ) can be brought into a working position through the opening ( 11 ) in the first cover ( 9 ), and
wherein the top lance ( 12 ) is rotatable around a longitudinal axis ( 17 ) of the top lance ( 12 ), is rotatable around a vertical axis ( 18 ), and/or is pivotable around a horizontal axis ( 19 ) during operation of the smelting unit ( 1 ), and
wherein a distance (h S ) between the surface ( 6 ) of the melt ( 7 ) and a tip ( 20 ) of the top lance ( 12 ) can be varied;
a second cover ( 13 ) closing the upper furnace ( 8 ) at the top, having at least one opening ( 14 ) for passage of one or more electrodes ( 27 ),
wherein the lower furnace ( 2 ) and the upper furnace ( 8 ) are designed for operation both with and without a melt current, and
wherein the first cover ( 9 ) can be exchanged for the second cover ( 13 ) during operation of the smelting unit ( 1 );
a plurality of side wall injectors ( 15 ) arranged radially circumferentially in the upper furnace ( 8 ) for injecting a process gas,
wherein the side wall injectors ( 15 ) can be pivoted horizontally and/or vertically by up to ±5°; and
a process gas control ( 16 ) for adjusting a pressure and/or a volume flow of the process gas for the top lance ( 12 ) and the side wall injectors ( 15 ).

19 . The smelting unit according to claim 18 ,
wherein the top lance ( 12 ) is a multi-hole top lance, and wherein the top lance ( 12 ) has more than 5 outlet openings ( 21 ) for the process gas.

20 . The smelting unit according to claim 18 ,
wherein the top lance ( 12 ) can be rotated by an angle of +/−45° around the longitudinal axis ( 17 ) of the top lance ( 12 ).

21 . The smelting unit according to claim 18 ,
wherein the top lance ( 12 ) can be rotated by an angle of +/−45° around the vertical axis ( 18 ) in the working position.

22 . The smelting unit according to claim 18 ,
wherein the top lance ( 12 ) can be pivoted by an angle of +/−30° around the horizontal axis ( 20 ).

23 . The smelting unit according to claim 18 ,
wherein the top lance ( 12 ) has at least one supersonic nozzle ( 22 ).

24 . The smelting unit according to claim 18 ,
wherein at least one outlet opening ( 21 ) is present in the top lance ( 12 ) for each gas jet emerging from a side wall injector ( 15 ).

25 . The smelting unit according to claim 18 ,
wherein the upper furnace ( 8 ) has more than six side wall injectors ( 15 ).

26 . The smelting unit according to claim 18 ,
wherein at least one side wall injector ( 15 ) can be switched between a burner mode and a blowing mode.

27 . The smelting unit according to claim 18 ,
wherein the top lance ( 12 ) and the side wall injectors ( 15 ) can be operated simultaneously and with coordinated volume flows for the process gas by a common gas station ( 22 ) or the process gas control ( 16 ).

28 . The smelting unit according to claim 18 ,
wherein 50% to 90% of a total volume flow of the process gas can be introduced through the top lance ( 12 ) and 10% to 50% of the total volume flow can be introduced through the side wall injectors ( 15 ).

29 . The smelting unit according to claim 18 ,
wherein the exhaust gas nozzle ( 10 ) is configured for discharging exhaust gas produced in the smelting unit at an exhaust gas flow velocity of V AG ≤50 m/s at an exhaust gas temperature of T AG ≥800° C., and wherein the exhaust gas nozzle ( 10 ) has an average diameter of 1.20 m to 3.5 m, and wherein the exhaust gas nozzle ( 10 ) is inclined with respect to the vertical axis in a range of +30° and has a flow-through length (I A ) of ≥2.0 m.

30 . A method, comprising:
providing smelting unit ( 1 ) for steel production with a tap weight between 60 t and 350 t, including
a lower furnace ( 2 ),
wherein the lower furnace ( 2 ) is refractory-lined and includes a tapping hole ( 3 ),
wherein a receptacle bottom ( 4 ) of the lower furnace ( 2 ) substantially corresponds to a spherically shaped shell section and
wherein a sphere from which the spherically shaped shell section originates geometrically has a radius≥5 m and ≤15 m, and
wherein a distance (d S ) between a lowest point of the receptacle bottom ( 4 ) in the lower furnace ( 2 ) and a surface ( 6 ) of a melt ( 7 ) located therein in an operating state is ≥0.5 m and ≤1.5 m;

an upper furnace ( 8 ),
wherein the upper furnace ( 8 ) is substantially cylindrical and water-cooled, and
wherein a height (h O ) of the upper furnace ( 8 ) is ≥3 m and a radius (r O ) of the upper furnace ( 8 ) is ≥2 m;

a first cover ( 9 ) closing the upper furnace ( 8 ) at a top, having an exhaust gas nozzle ( 10 ) and at least one opening ( 11 ) for inserting a top lance ( 12 ) into the smelting unit ( 1 )
wherein the top lance ( 12 ) can be brought into a working position through the opening ( 11 ) in the first cover ( 9 ), and
wherein the top lance ( 12 ) is rotatable around a longitudinal axis ( 17 ) of the top lance ( 12 ), is rotatable around a vertical axis ( 18 ), and/or is pivotable around a horizontal axis ( 19 ) during operation of the smelting unit ( 1 ), and
wherein a distance (h S ) between the surface ( 6 ) of the melt ( 7 ) and a tip ( 20 ) of the top lance ( 12 ) can be varied;

a second cover ( 13 ) closing the upper furnace ( 8 ) at the top, having at least one opening ( 14 ) for passage of one or more electrodes ( 27 ),
wherein the lower furnace ( 2 ) and the upper furnace ( 8 ) are designed for operation both with and without a melt current, and
wherein the first cover ( 9 ) can be exchanged for the second cover ( 13 ) during operation of the smelting unit ( 1 );

a plurality of side wall injectors ( 15 ) arranged radially circumferentially in the upper furnace ( 8 ) for injecting a process gas,
wherein the side wall injectors ( 15 ) can be pivoted horizontally and/or vertically by up to +5°; and

a process gas control ( 16 ) for adjusting a pressure and/or a volume flow of the process gas for the top lance ( 12 ) and the side wall injectors ( 15 ); and operating the smelting unit by performing the following steps:
a) creating the melt ( 7 ) having the surface ( 6 );
b) injecting the process gas onto the surface ( 6 ) by the side wall injectors ( 15 );
c) lowering the top lance ( 12 ) into a first working position ( 23 ) and injecting the process gas onto the surface ( 6 ) through the top lance ( 12 );
d) aligning the top lance ( 12 ) by rotating, changing the distance (h S ), and/or pivoting the top lance ( 12 ) to a second working position ( 24 ), such

Assignees

• Sms Group Gmbh

Inventors

• Odenthal Hans-Jürgen
• Schüring Andreas
• Starke Peter
• Henkel Thomas

Classifications

• C21C5/5252 Primary

  in an electrically heated multi-chamber furnace, a combination of electric furnaces or an electric furnace arranged for associated working with a non electric furnace · CPC title

• C21C5/5217

  equipped with burners or devices for injecting gas, i.e. oxygen, or pulverulent materials into the furnace · CPC title

• C21C5/462

  Means for handling, e.g. adjusting, changing, coupling · CPC title

• F27D2099/004

  directed upon the charge, e.g. vertically · CPC title

• F27D2019/004

  Fuel quantity · CPC title