US3802684A - Tuyere construction - Google Patents

Tuyere construction Download PDF

Info

Publication number
US3802684A
US3802684A US00284694A US28469472A US3802684A US 3802684 A US3802684 A US 3802684A US 00284694 A US00284694 A US 00284694A US 28469472 A US28469472 A US 28469472A US 3802684 A US3802684 A US 3802684A
Authority
US
United States
Prior art keywords
shape
tuyere
construction according
vessel
tuyere construction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00284694A
Inventor
F Rote
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
United States Steel Corp
Original Assignee
Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Steel Corp filed Critical Steel Corp
Priority to US00284694A priority Critical patent/US3802684A/en
Priority to CA174,254A priority patent/CA977142A/en
Priority to GB3739273A priority patent/GB1408994A/en
Priority to ZA735372A priority patent/ZA735372B/en
Priority to AU59016/73A priority patent/AU472629B2/en
Priority to DE19732342067 priority patent/DE2342067A1/en
Priority to IT69570/73A priority patent/IT996624B/en
Priority to HUUE41A priority patent/HU166326B/hu
Priority to FR7331143A priority patent/FR2329752A1/en
Priority to SU1957227A priority patent/SU550989A3/en
Application granted granted Critical
Publication of US3802684A publication Critical patent/US3802684A/en
Assigned to USX CORPORATION, A CORP. OF DE reassignment USX CORPORATION, A CORP. OF DE MERGER (SEE DOCUMENT FOR DETAILS). Assignors: UNITED STATES STEEL CORPORATION (MERGED INTO)
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/46—Details or accessories
    • C21C5/48—Bottoms or tuyéres of converters

Definitions

  • ABSTRACT 52 us. Cl. 266/41, 266/35 A tuyere Construction for a Steelmaking vessel
  • Int. Cl. C2lc 5/48 has an inner tube of a noncirculal' Oblong Cross"
  • the opening usually UNITED STATES PATENTS has a spacing substantially equal all around the inner t b 3,706,549 12/1972 Knuppel et a1.
  • a vessel has a removable bottom or plug which contains one or more tuyeres through which oxygen and other gases or particulate matter such as lime or other flux are blown into the vessel.
  • Each tuyere comprises an oxygen inlet tube surrounded by a larger concentric inlet tube for the simultaneous injection of a jacket gas. This jacket gas acts as a coolant, reducing the rate of reaction between the molten metal and the oxygen adjacent the tuyere preventing rapid erosion of the tuyere.
  • tuyeres have been of symmetrical cross-section, generally cylindrically shaped, the outer tube being spaced from the inner tube by a number of small beads welded to one of the tubes, or by a spiral of wire welded to one of the tubes, or by any other convenient means for maintaining concentricity.
  • spitting is the propulsion of bath and slag material onto the upper walls and nose of the vessel. Severe spitting can result in actually blocking the mouth of the vessel. This requires that the solidified material in the mouth of the vessel be removed mechanically, which, of course, necessitates shutting down the operation of the vessel. Removal of solidified material also damages the refractory lining of the vessel necessitating repair and long vessel shutdown periods.
  • the bath depth depends upon the amount of wear of the lining of the vessel, especially around the sides and thus cannot be well controlled. Further, if it were desirable to add more metal to the bath to increase the bath depth, this would increase the heat size, and it is probable that the tapping equipment would be required to be modified to accommodate such larger heat size. In order to reduce spitting by reducing the oxygen flow rate, one would necessarily increase the blowing time of the heat which is extremely undesirable as it increases the tap-to-tap time and correspondingly reduces production. Therefore, the only variable which can readily be controlled is the tuyere size.
  • My tuyere can have any elongated shape wherein its length to width ratio is 2 to l or greater, which has the same cross-sectional area as a circular tuyere for the required oxygen flow rate. This tuyere will reduce spitting in the vessel markedly in comparison to a round tuyere of the same cross-sectional area, having the same oxygen flow rate in a vessel with the same bath depth.
  • FIG. 1 is a cross-sectional view of a bottom blown oxygen steelmaking vessel
  • FIG. 2 is an enlarged vertical crosssectional view taken through a conventional tuyere and the bath above the tuyere having velocity curves superimposed on the gas jet;
  • FIG. 3 is an isometric view of one embodiment of my tuyere construction
  • FIG. 4 is a horizontal cross-section view of the embodiment of FIG. 3;
  • FIG. 5 is a cross-sectional view of an additional embodiment of my tuyere construction having a semicircular cross-section
  • FIG. 6 is a cross-sectional view of a rectangular tuyere construction
  • FIG. 7 is a cross-sectional view of a rhombic tuyere construction.
  • FIG. 8 is a cross-sectional view of a triangular tuyere.
  • a bottom blown oxygen steelmaking vessel 10 has a refractory lining l2 and a removable bottom 13, comprising a bottom plate 14, and one or more generally upstanding tuyeres 16, which are surrounded by a refractory material 18.
  • the bottom plate 14 is fastened to the furnace by bolts 20.
  • the sides of the refractory portion of the removable bottom do not contact the refractory lining 12 of the vessel, but sufficient clearance is provided around the bottom for inserting a gunning mixture 24 to provide a metal and slag-tight seal.
  • dual concentric tuyere 16 comprising inner tube 30 and outer tube 32 is located in the bottom of a vessel.
  • Tube 30 is spaced from tube 32 by spacers 34 which maybe weld beads as shown in FIGS. 3 and 4, spiral wound wire or any other suitable means for maintaining concentricity.
  • the central tube 30 delivers oxygen and lime to the molten metal bath.
  • a jacketing gas which is, in this case, natural gas, is delivered to the bath through the annular space 36 between the central tube 30 and the outer tube 32.
  • the gases diffuse into the bath or mix with the bath as bubbles, leaving a gas pocket 40 generally as indicated on the drawing which is roughly in the shape of a candle flame.
  • the oxygen pressure should be equal to or greater than that of the jacket gas.
  • the velocity of the gases is sonic at their entrance into the bath, however, the velocity curves superimposed upon the gas pocket in FIG. 2 show that the velocities are low at the edge of the pocket due to interaction with the bath and higher at the center until the gas is totally dissipated. Should this gas pocket or jet become so elongated as to penetrate the surface of the bath, an extremely great amount of spitting would occur.
  • the xaxis of the velocity curve represents the distance (d) from the central vertical axis of the gas jet.
  • the y-axis represents the velocity (v) of the gas as it varies from zero to sonic velocity.
  • any noncircular oblong shape will have the effect of reducing the height of the jet of gas in the bath and thus will reduce the tendency of spitting to occur in such bath.
  • Any elongated shape will accomplish this.
  • Some suitable shapes are a triangle, rectangle, half circle, diamond or rhombus, ellipse or pointed ellipse.
  • the length to width ratio of the cross-section of the shape would be 2 to l or more. Although it usually would be, it need not be symmetrical about a center line.
  • a second advantage is present for these oblong tuyeres.
  • the larger interface which is provided by the elongated jet stream gives a more rapid and better dephosphorization of the bath. Dephosphorization occurs at the interface between the gas jet and this molten metal bath. This is an important difference between Q-BOP and BOP steelmaking.
  • BOP dephosphorization occurs by metal reaction with the surface slag layer.
  • Q-BOP dephosphorization primarily occurs at the surface of the jet within the bath where FeO, phosphorus and CaO are present.
  • the CaO is derived from the powdered lime blown with the oxygen.
  • the FeO is formed through reaction of blown-in oxygen and Fe in the bath.
  • the phosphorus is a normal contaminant of the charged blast furnace hot metal.
  • said tuyere construction comprising a plurality of substantially vertical tuyeres, each of which includes:
  • an inner tube of a noncircular oblong cross-sectional shape which shape has a length to width ratio of at least 2 to 1;
  • spacers interposed between said tubes to form an annular space between the inner and outer tubes.
  • a tuyere construction according to claim 2 which said shape is elliptical.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

A tuyere construction for a Q-BOP steelmaking vessel has an inner tube of a noncircular oblong cross-sectional shape and an outer tube of like shape, the inner and outer tubes being spaced apart to form an annular opening therebetween. The opening usually has a spacing substantially equal all around the inner tube.

Description

United States Patent [191 Rote Apr. 9, 1974 [54] TUYERE CONSTRUCTION 3,458,134 7/1969 Shimotsuma et al 266/34 L x [75] Inventor: Franklin E. Rote, Homewood, Ill. FOREIGN PATENTS OR APPLICATIONS [73] Assignee: United States Steel Corporation, 56,395 3/1891 Germany 266/35 Pittsburgh, Pa. Primary ExaminerGerald A. Dost V [22] Flled: 1972 Attorney, Agent, or FirmRalph H. Dougherty [21] AppLyNo; 284,694
[57] ABSTRACT 52 us. Cl. 266/41, 266/35 A tuyere Construction for a Steelmaking vessel [51] Int. Cl. C2lc 5/48 has an inner tube of a noncirculal' Oblong Cross" [58] Field of Search 266/35, 36 P, 41; 75/60 sectional Shape and an Outer tube of like shape, the inner and outer tubes being spaced apart to form an 5 References Cited annular opening therebetween. The opening usually UNITED STATES PATENTS has a spacing substantially equal all around the inner t b 3,706,549 12/1972 Knuppel et a1. 266/35 u 6 3,397,878 8/1968 Holmes et al 266/41 9 Claims, 8 Drawing Figures I I Z TUYERE CONSTRUCTION In the bottom blown oxygen steelmaking process, which is known as the Q-BOP process, a vessel has a removable bottom or plug which contains one or more tuyeres through which oxygen and other gases or particulate matter such as lime or other flux are blown into the vessel. Each tuyere comprises an oxygen inlet tube surrounded by a larger concentric inlet tube for the simultaneous injection of a jacket gas. This jacket gas acts as a coolant, reducing the rate of reaction between the molten metal and the oxygen adjacent the tuyere preventing rapid erosion of the tuyere. Thus the furnace lining and the tuyere wear at the same rate. Heretofore, tuyeres have been of symmetrical cross-section, generally cylindrically shaped, the outer tube being spaced from the inner tube by a number of small beads welded to one of the tubes, or by a spiral of wire welded to one of the tubes, or by any other convenient means for maintaining concentricity.
In the bottom blown steelmaking process, spitting" is quite common. Spitting is the propulsion of bath and slag material onto the upper walls and nose of the vessel. Severe spitting can result in actually blocking the mouth of the vessel. This requires that the solidified material in the mouth of the vessel be removed mechanically, which, of course, necessitates shutting down the operation of the vessel. Removal of solidified material also damages the refractory lining of the vessel necessitating repair and long vessel shutdown periods.
I have determined that spitting is dependent upon three factors: (I the depth of the bath, (2) the oxygen flow rate, and (3) the tuyere size. lhave observed that heats made with bottoms having small tuyere openings have less spitting than heats made with bottoms having large tuyere openings, provided the gas pressures at the tuyere inlets are equal.
The bath depth depends upon the amount of wear of the lining of the vessel, especially around the sides and thus cannot be well controlled. Further, if it were desirable to add more metal to the bath to increase the bath depth, this would increase the heat size, and it is probable that the tapping equipment would be required to be modified to accommodate such larger heat size. In order to reduce spitting by reducing the oxygen flow rate, one would necessarily increase the blowing time of the heat which is extremely undesirable as it increases the tap-to-tap time and correspondingly reduces production. Therefore, the only variable which can readily be controlled is the tuyere size.
I have invented a tuyere construction that reduces spitting, yet allows the same amount of gas flow as a large tuyere because it has the same cross-sectional area.
My tuyere can have any elongated shape wherein its length to width ratio is 2 to l or greater, which has the same cross-sectional area as a circular tuyere for the required oxygen flow rate. This tuyere will reduce spitting in the vessel markedly in comparison to a round tuyere of the same cross-sectional area, having the same oxygen flow rate in a vessel with the same bath depth.
It is the principal object of this invention to provide a tuyere construction for a bottom blown oxygen steelmaking vessel which will reduce spitting in the vessel.
It is another object to provide a tuyere construction which will deliver oxygen to the vessel at the optimum flow rate.
These and other objects will become more apparent by referring to the following specification and the ap pended drawings in which:
FIG. 1 is a cross-sectional view of a bottom blown oxygen steelmaking vessel;
FIG. 2 is an enlarged vertical crosssectional view taken through a conventional tuyere and the bath above the tuyere having velocity curves superimposed on the gas jet;
FIG. 3 is an isometric view of one embodiment of my tuyere construction;
FIG. 4 is a horizontal cross-section view of the embodiment of FIG. 3;
FIG. 5 is a cross-sectional view of an additional embodiment of my tuyere construction having a semicircular cross-section;
FIG. 6 is a cross-sectional view of a rectangular tuyere construction;
FIG. 7 is a cross-sectional view of a rhombic tuyere construction; and
FIG. 8 is a cross-sectional view of a triangular tuyere.
construction.
As shown in FIG. 1, a bottom blown oxygen steelmaking vessel 10 has a refractory lining l2 and a removable bottom 13, comprising a bottom plate 14, and one or more generally upstanding tuyeres 16, which are surrounded by a refractory material 18. The bottom plate 14 is fastened to the furnace by bolts 20. The sides of the refractory portion of the removable bottom do not contact the refractory lining 12 of the vessel, but sufficient clearance is provided around the bottom for inserting a gunning mixture 24 to provide a metal and slag-tight seal.
As can be seen in FIG. 2, dual concentric tuyere 16, comprising inner tube 30 and outer tube 32 is located in the bottom of a vessel. Tube 30 is spaced from tube 32 by spacers 34 which maybe weld beads as shown in FIGS. 3 and 4, spiral wound wire or any other suitable means for maintaining concentricity. The central tube 30 delivers oxygen and lime to the molten metal bath. A jacketing gas, which is, in this case, natural gas, is delivered to the bath through the annular space 36 between the central tube 30 and the outer tube 32. Upon emergence of the gases into the bath, they expand as shown in FIG. 2. The gases diffuse into the bath or mix with the bath as bubbles, leaving a gas pocket 40 generally as indicated on the drawing which is roughly in the shape of a candle flame. The oxygen pressure should be equal to or greater than that of the jacket gas. The velocity of the gases is sonic at their entrance into the bath, however, the velocity curves superimposed upon the gas pocket in FIG. 2 show that the velocities are low at the edge of the pocket due to interaction with the bath and higher at the center until the gas is totally dissipated. Should this gas pocket or jet become so elongated as to penetrate the surface of the bath, an extremely great amount of spitting would occur. The xaxis of the velocity curve represents the distance (d) from the central vertical axis of the gas jet. The y-axis represents the velocity (v) of the gas as it varies from zero to sonic velocity.
I have found that any noncircular oblong shape will have the effect of reducing the height of the jet of gas in the bath and thus will reduce the tendency of spitting to occur in such bath. Any elongated shape will accomplish this. Some suitable shapes are a triangle, rectangle, half circle, diamond or rhombus, ellipse or pointed ellipse. The length to width ratio of the cross-section of the shape would be 2 to l or more. Although it usually would be, it need not be symmetrical about a center line.
A second advantage is present for these oblong tuyeres. The larger interface which is provided by the elongated jet stream gives a more rapid and better dephosphorization of the bath. Dephosphorization occurs at the interface between the gas jet and this molten metal bath. This is an important difference between Q-BOP and BOP steelmaking. In the BOP dephosphorization occurs by metal reaction with the surface slag layer. In the Q-BOP dephosphorization primarily occurs at the surface of the jet within the bath where FeO, phosphorus and CaO are present. The CaO is derived from the powdered lime blown with the oxygen. The FeO is formed through reaction of blown-in oxygen and Fe in the bath. The phosphorus is a normal contaminant of the charged blast furnace hot metal.
It is readily apparent from the foregoing that l have invented a tuyere construction for a Q-BOP steelmaking vessel which will reduce spitting in the vessel yet will deliver oxygen to the bath at the optimum flow rate.
I claim:
1. In a bottom blown oxygen steelmaking vessel, an
improved large tuyere construction for minimizing spitting in the vessel but delivering oxygen to the vessel at an optimum flow rate, said tuyere construction comprising a plurality of substantially vertical tuyeres, each of which includes:
an inner tube of a noncircular oblong cross-sectional shape, which shape has a length to width ratio of at least 2 to 1;
an outer tube of like shape; and
spacers interposed between said tubes to form an annular space between the inner and outer tubes.
2. A tuyere construction according to claim 1 in which the annular space is substantially equidistant all around the inner tube.
3. A tuyere construction according to claim 1 in which said shape is symmetrical about a center line.
4. A tuyere construction according to claim 2 which said shape is elliptical.
5. A tuyere construction according to which said shape is semicircular.
6. A tuyere construction according to which said shape is rectangular.
7. A tuyere construction according to which said shape is rhombic.
8. A tuyere construction according to which said shape is triangular.
9. A tuyere construction according to which said shape is a pointed ellipse.
claim 2 in claim 2 in claim 2 claim 1 claim 2

Claims (9)

1. In a bottom blown oxygen steelmaking vessel, an improved large tuyere construction for minimizing spitting in the vessel but delivering oxygen to the vessel at an optimum flow rate, said tuyere construction comprising a plurality of substantially vertical tuyeres, each of which includes: an inner tube of a noncircular oblong cross-sectional shape, which shape has a length to width ratio of at least 2 to 1; an outer tube of like shape; and spacers interposed between said tubes to form an annular space between the inner and outer tubes.
2. A tuyere construction according to claim 1 in which the annular space is substantially equidistant all around the inner tube.
3. A tuyere construction according to claim 1 in which said shape is symmetrical about a center line.
4. A tuyere construction according to claim 2 in which said shape is elliptical.
5. A tuyere construction according to claim 2 in which said shape is semicircular.
6. A tuyere construction according to claim 2 in which said shape is rectangular.
7. A tuyere construction according to claim 2 in which said shape is rhombic.
8. A tuyere construction according to claim 1 in which said shape is triangular.
9. A tuyere construction according to claim 2 in which said shape is a pointed ellipse.
US00284694A 1972-08-28 1972-08-29 Tuyere construction Expired - Lifetime US3802684A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US00284694A US3802684A (en) 1972-08-29 1972-08-29 Tuyere construction
CA174,254A CA977142A (en) 1972-08-29 1973-06-18 Tuyere construction
GB3739273A GB1408994A (en) 1972-08-29 1973-08-07 Tuyere construction
ZA735372A ZA735372B (en) 1972-08-29 1973-08-07 Tuyere construction
AU59016/73A AU472629B2 (en) 1972-08-28 1973-08-08 Tuyere construction
DE19732342067 DE2342067A1 (en) 1972-08-29 1973-08-20 BLOW MOLD FOR BOTTOM BUBBLING FRESH CONTAINERS
IT69570/73A IT996624B (en) 1972-08-29 1973-08-27 INSUFFLATION NOZZLE FOR OROGIOLO FOR THE MANUFACTURE OF STEEL
HUUE41A HU166326B (en) 1972-08-29 1973-08-28
FR7331143A FR2329752A1 (en) 1972-08-29 1973-08-28 CONSTRUCTION OF PIPES FOR BOTTOM OXYGEN BLOWING REFINING OVEN
SU1957227A SU550989A3 (en) 1972-08-29 1973-08-28 Tuyere

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00284694A US3802684A (en) 1972-08-29 1972-08-29 Tuyere construction

Publications (1)

Publication Number Publication Date
US3802684A true US3802684A (en) 1974-04-09

Family

ID=23091177

Family Applications (1)

Application Number Title Priority Date Filing Date
US00284694A Expired - Lifetime US3802684A (en) 1972-08-28 1972-08-29 Tuyere construction

Country Status (10)

Country Link
US (1) US3802684A (en)
AU (1) AU472629B2 (en)
CA (1) CA977142A (en)
DE (1) DE2342067A1 (en)
FR (1) FR2329752A1 (en)
GB (1) GB1408994A (en)
HU (1) HU166326B (en)
IT (1) IT996624B (en)
SU (1) SU550989A3 (en)
ZA (1) ZA735372B (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4815715A (en) * 1986-10-09 1989-03-28 Didier-Werke Ag Gas purging assembly for supplying gas to molten metal in a metallurgical vessel
AT391483B (en) * 1986-12-02 1990-10-10 Radex Austria Ag CONTAINER FOR TREATING HIGHLY MELTING MATERIALS, REFRACTORY STONE FOR DELIVERY AND METHOD FOR OPERATING SUCH A CONTAINER
US5329545A (en) * 1991-12-07 1994-07-12 Air Products And Chemicals, Inc. Tuyere for installation in hearth of electric arc furnace
US20060264824A1 (en) * 2005-05-20 2006-11-23 Swisher Kyle Y Iii Disposable safety medical syringe assembly and method of manufacture
US11667982B2 (en) * 2021-01-26 2023-06-06 University Of Science And Technology Beijing Long-life service method for powder-bottom-injecting converter based on collaborative hot replacement of furnace bottom and bottom purging brick

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2431542A1 (en) * 1978-07-19 1980-02-15 Creusot Loire BLOW NOZZLE
NL8600608A (en) * 1986-03-10 1987-10-01 Hoogovens Groep Bv CONVERTER FOR PREPARING STEEL.
DE3919238A1 (en) * 1989-06-13 1990-12-20 Voest Alpine Ind Anlagen RINSING DEVICE FOR A METALLURGICAL VESSEL

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD56395A (en) *
US3397878A (en) * 1965-11-19 1968-08-20 Union Carbide Corp Under-bath tuyere
US3458134A (en) * 1965-02-24 1969-07-29 Nippon Kokan Kk Lance structure for refining metals by oxygen blast
US3706549A (en) * 1968-02-24 1972-12-19 Maximilianshuette Eisenwerk Method for refining pig-iron into steel

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD56395A (en) *
US3458134A (en) * 1965-02-24 1969-07-29 Nippon Kokan Kk Lance structure for refining metals by oxygen blast
US3397878A (en) * 1965-11-19 1968-08-20 Union Carbide Corp Under-bath tuyere
US3706549A (en) * 1968-02-24 1972-12-19 Maximilianshuette Eisenwerk Method for refining pig-iron into steel

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4815715A (en) * 1986-10-09 1989-03-28 Didier-Werke Ag Gas purging assembly for supplying gas to molten metal in a metallurgical vessel
AT391483B (en) * 1986-12-02 1990-10-10 Radex Austria Ag CONTAINER FOR TREATING HIGHLY MELTING MATERIALS, REFRACTORY STONE FOR DELIVERY AND METHOD FOR OPERATING SUCH A CONTAINER
US5329545A (en) * 1991-12-07 1994-07-12 Air Products And Chemicals, Inc. Tuyere for installation in hearth of electric arc furnace
US20060264824A1 (en) * 2005-05-20 2006-11-23 Swisher Kyle Y Iii Disposable safety medical syringe assembly and method of manufacture
US11667982B2 (en) * 2021-01-26 2023-06-06 University Of Science And Technology Beijing Long-life service method for powder-bottom-injecting converter based on collaborative hot replacement of furnace bottom and bottom purging brick

Also Published As

Publication number Publication date
FR2329752B1 (en) 1978-03-24
HU166326B (en) 1975-02-28
DE2342067A1 (en) 1974-03-07
FR2329752A1 (en) 1977-05-27
AU472629B2 (en) 1976-05-27
ZA735372B (en) 1974-07-31
GB1408994A (en) 1975-10-08
AU5901673A (en) 1975-02-13
CA977142A (en) 1975-11-04
SU550989A3 (en) 1977-03-15
IT996624B (en) 1975-12-10

Similar Documents

Publication Publication Date Title
US3330645A (en) Method and article for the injection of fluids into hot molten metal
US3706549A (en) Method for refining pig-iron into steel
SU797593A3 (en) Tuyere nozzle for metal blasting with oxygen and protective gas
SU727153A3 (en) Method of convertor reprocessing of high-phosphorus cast iron into steel
US2829960A (en) Method and metallurgical device for the refining of steel
US3802684A (en) Tuyere construction
US4541617A (en) Lance structure for oxygen-blowing process in top-blown converters
US4366953A (en) Oxygen lance
US3802685A (en) Q-bop vessel construction
US3697058A (en) Oxygen toyere of a steel-melting mill
US5911946A (en) Snorkel for a degassing vessel
US3992194A (en) Method and apparatus for use in the treatment of metals in the liquid state
US20030090044A1 (en) Method and apparatus for melting metal in a shaft furnace
US2829879A (en) Bottoms for metallurgical furnaces of the bessemer converter type
US3907549A (en) Method of refining in improved Q-BOP vessel
US3793001A (en) Process for manufacturing steel
US3898077A (en) Process for refining metal melts
US3774893A (en) Steel making converter
EP0394443B1 (en) Method and apparatus for preliminary treatment of hot metal
US3809381A (en) Lime oxygen-natural gas distribution system
US4347079A (en) Method of operating an open-hearth furnace
US3118608A (en) Fuel gas and oxygen injection lance employing webbed coolant deflectors
JPS61207505A (en) Bottom blowing nozzle of refining furnace for molten metal
US3722871A (en) Blast furnace with staggered tuyere system
SU1268615A1 (en) Method of blowing molten metal

Legal Events

Date Code Title Description
AS Assignment

Owner name: USX CORPORATION, A CORP. OF DE, STATELESS

Free format text: MERGER;ASSIGNOR:UNITED STATES STEEL CORPORATION (MERGED INTO);REEL/FRAME:005060/0960

Effective date: 19880112