US3897047A - Apparatus for and method of refining an iron base melt - Google Patents

Apparatus for and method of refining an iron base melt Download PDF

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Publication number
US3897047A
US3897047A US309037A US30903772A US3897047A US 3897047 A US3897047 A US 3897047A US 309037 A US309037 A US 309037A US 30903772 A US30903772 A US 30903772A US 3897047 A US3897047 A US 3897047A
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pressure
flow
tuyere
gas stream
oxygen
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US309037A
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William A Kolb
Jack F Sigh
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United States Steel Corp
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United States Steel Corp
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Application filed by United States Steel Corp filed Critical United States Steel Corp
Priority to US309037A priority Critical patent/US3897047A/en
Priority to YU01831/73A priority patent/YU183173A/xx
Priority to JP8276873A priority patent/JPS5729528B2/ja
Priority to HUUE39A priority patent/HU167535B/hu
Priority to NL7310470A priority patent/NL7310470A/xx
Priority to GB3587573A priority patent/GB1456977A/en
Priority to LU68115A priority patent/LU68115A1/xx
Priority to FR7327682A priority patent/FR2194784B1/fr
Priority to CA177,498A priority patent/CA993195A/en
Priority to DE2338241A priority patent/DE2338241C2/de
Priority to ES417320A priority patent/ES417320A1/es
Priority to IT27218/73A priority patent/IT995081B/it
Priority to AT662073A priority patent/AT341557B/de
Priority to SE7310431A priority patent/SE426344B/xx
Priority to US05/524,104 priority patent/US3970446A/en
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Publication of US3897047A publication Critical patent/US3897047A/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)
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    • 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
    • C21C5/30—Regulating or controlling the blowing
    • C21C5/35—Blowing from above and through the bath

Definitions

  • ABSTRACT A method of oxygen refining molten hot metal to steel by blowing an oxygen stream at a predetermined flow rate from an oxygen supply source having a pressure from about 12 to about 18 atmospheres through the molten hot metal from a tuyere located beneath the surface of the molten hot metal and having a tuyere inlet and by varying the rate of flow of a finely divided lime injected into the oxygen stream is disclosed.
  • the method includes the steps of supplying oxygen from the oxygen supply source to the tuyere inlet at the predetermined oxygen flow rate for refining the molten hot metal; controlling the pressure of the oxygen stream at the tuyere inlet at a value which is about three atmospheres less than the difference between the pressure of the oxygen supply source and the oxygen pressure drop resulting from supplying the oxygen stream from the oxygen supply source to the tuyere inlet; injecting the finely divided lime into the oxygen stream at an injection point prior to the entry of the oxygen stream into the tuyere inlet; and increasing the pressure of the oxygen stream upstream of the injection point to maintain substantially constant the predetermined oxygen flow rate.
  • Apparatus for refining the iron base melt by blowing a gas stream at a predetermined flow rate and containing a suspended particulate solid into the iron base melt through a tuyere located beneath the surface of the iron base melt and having a tuyere inlet is also disclosed.
  • the apparatus has a gas supply source at super atmospheric pressure; a main oxygen supply line connecting the gas supply source to the tuyere inlet for supplying the gas stream to the tuyere inlet at the predetermined flow rate for refining the iron base melt; injection means for suspending the suspended particulate solid in the gas stream and for injecting the suspended particulate solid at a particulate injection point in the main oxygen supply line prior to entry of the gas stream and suspended particulate solid into the tuyere inlet thereby increasing the pressure drop of the gas stream resulting from the passage of the gas stream and the suspended particulate solid through the injection means and the main oxygen supply line; flow control means in communication with the main oxygen supply line prior to the particulate injection point for sensing the flow of the gas stream; valve means connected to the flow control means and in communication with the main oxygen supply line prior to the particulate injection point for controlling the flow of the gas stream through said main oxygen supply line; and the flow control means being operable to adjust the valve means in the main oxygen supply line to maintain substantially constant the
  • oxygen is blown into the bottom of the converter or vessel during the refining of the molten hot metal to steel.
  • a flux such as finely divided lime or the like
  • it is injected along with the oxygen through a plurality of tuyeres located in the bottom of the converter into the molten metal bath.
  • a back pressure results which decreases the oxygen flow rate.
  • the back pressure is removed and the oxygen flow rate increases back to its normal or prior flow.
  • the total source oxygen pressure is applied to the tuyeres, thereby resulting in sonic flow or flow velocities greater than Mach 1.0 to the tuyere outlet.
  • Manufacturers of such conventional process claim that this re sults in a better oxygen distribution in the molten metal bath and requires the minimum number of tuyeres in the bottom of the converter.
  • the maximum oxygen flow rate attainable in the conventional system is hence fixed by the oxygen source pressure and the number and size of the tuyeres employed in the Q-BOP converter.
  • the increased back pressure results in decreased oxygen flow through the tuyeres and since the oxygen source pressure cannot be increased (because full source pressure has been applied) to overcome this back pressure, the oxygen flow rate remains lower during the flux injection.
  • the oxygen pressure in the tuyere during the flux injection is still high enough to maintain the sonic flow of the oxygen through the tuyere outlet and to prevent the molten steel in the bath from moving downwardly through the tuyeres.
  • the oxygen flow rate varies directly as the oxygen pressure so that a drop in tuyere oxygen pressure would result in a directly proportional drop in the oxygen flow rate through the tuyeres.
  • An advantage of this conventional system is that the oxygen pressure at the tuyeres is maintained higher than is necessary at all times, thereby eliminating any possibility of the passage of hot molten metal from the bath into the tuyeres.
  • the Q-BOP converter can be operated with larger and a greater number of tuyeres with oxygen flow through such tuyeres below sonic flow velocities without adverse affect on the oxygen distribution in the hot molten bath.
  • the increased back pressure would also result in lower pressure at and decreased oxygen flow through the tuyeres.
  • the oxygen flow rate at subsonic velocities varies as the square root of the oxygen pressure changes, the oxygen flow rate per unit change in oxygen pressure is considerable less.
  • the margin between the operating source oxygen pressure and the minimum oxygen pressure required to keep the hot molten metal out of the tuyeres during flux injection is much less, and therefore is more critical. Since all of the source oxygen pressure has not been applied to the tuyeres, there is a reserve oxygen pressure at the oxygen pressure source which is available to preserve the margin between the required operating pressures to maintain the oxygen flow rate through the tuyeres and the minimum allowable oxygen operating pressure on the tuyeres which will keep the hot molten metal out of the tuyeres.
  • I. operate below sonic velocities of Mach l.0 and in the subsonic range of from about 0.7 to about 0.8 Mach 1.0 velocities;
  • the method includes the steps of supplying oxygen from the oxygen supply source to the tuyere inlet at the predetermined oxygen flow rate for refining the molten hot metal; controlling the pressure of the oxygen stream at the tuyere inlet at a value which is about three atmospheres less than the difference between the pressure of the oxygen supply source and the oxygen pressure drop resulting from supplying the oxygen stream from the oxygen supply source to the tuyere inlet; injecting the finely divided lime into the oxygen stream at an injection point prior to the entry of the oxygen stream into the tuyere inlet; and increasing the pressure of the oxygen stream upstream of the injection point to maintain substantially constant the predetermined oxygen flow rate.
  • Apparatus for refining the iron base melt by blowing a gas stream at a predetermined flow rate and containing a suspended particulate solid into the iron base melt through a tuyere located beneath the surface of the iron base melt and having a tuyere inlet is also disclosed.
  • the apparatus has a gas supply source at super atmospheric pressure; a main oxygen supply line connecting the gas supply source to the tuyere inlet for supplying the gas stream to the tuyere inlet at the predetermined flow rate for refining the iron base melt; injection means for suspending the suspended particulate solid in the gas stream and for injecting the suspended particulate solid at a particulate injection point in the main oxygen supply line prior to entry of the gas stream and the suspended particulate solid into the tuyere inlet thereby increasing the pressure drop of the gas stream resulting from the passage of the gas stream and the suspended particulate solid through the injection means and the main oxygen supply line; flow control means in communication with the main oxygen supply line prior to the particulate injection point for sensing the flow of the gas stream; valve means connected to the flow control means and in communication with the main oxygen supply line prior to the particulate injection point for controlling the flow of the gas stream through said main oxygen supply line; and the flow control means being operable to adjust the valve means in the main oxygen supply line to maintain substantially constant
  • FIG. 1 is a diagrammatic view of a Q-BOP type converter and a preferred embodiment of the improved oxygen flow rate and pressure control apparatus for practicing the improved method of the present invention for refining an iron base melt into steel;
  • FIG. 2 is a vertical sectional view of a bottom blown oxygen converter showing a pair of submerged bottom tuyeres, a pair of side submerged tuyeres, and a pair of side tuyeres directed toward the carbon monoxide zone of the furnace;
  • FIG. 3 is a vertical sectional view of an electric-arc steelmaking furnace showing a bottom vertical and bottom inclined submerged tuyere, a pair of side submerged tuyeres and a side tuyere directed toward the carbon monoxide zone of the furnace;
  • FIG. 4 is a vertical sectional view of an open hearth furnace utilizing a vertical and inclined bottom submerged tuyere, a side submerged tuyere and another side tuyere directed toward the carbon monoxide zone of the furnace;
  • FIG. 5 is a vertical sectional view of a tiltable open hearth furnace having a vertical and an inclined bottom submerged tuyere, a side submerged tuyere and side tuyere directed toward the carbon monoxide zone of the furnace;
  • FIG. 6 is a vertical sectional view of oscillatable hot metal mixer having an inclined bottom and vertical bottom submerged tuyeres, a pair of side submerged tuyeres and a side tuyere directed toward the carbon monoxide zone of the mixer.
  • this invention is particularly adapted for use in conjunction with a control of the flow rate and the pressure of oxygen flow through the tuyeres of a Q-BOP type converter, and hence it has been so illustrated and will be so described.
  • a O-BOP type converter is indicated generally by the reference numeral 10.
  • This Q-BOP converter 10 is rotatable about a horizontal axis AA defined by trunnions l2 and is provided with a removable bottom plug 14 in which are mounted a plurality of tuyeres 16, each surrounded by a concentric outer pipe 16a which defines with each tuyere 16 a shroud fluid annulus 17.
  • the improved method of oxygen refining the molten hot metal 18 in the Q-BOP converter 10 to steel consists of blowing an oxygen stream at a predetermined flow rate R1 at each tuyere inlet 20 from an oxygen supply source indicated by the legend FROM OXY- GEN SUPPLY.
  • the oxygen supply source has a pres sure from about 12 to about 18 atmospheres.
  • the oxygen stream is blown through the molten hot metal 18 from the tuyeres 16 located in the bottom plug 14 beneath the surface of the molten hot metal 18.
  • the improved method also varies the rate of flow of the oxygen stream containing a suspended particulate solid, such as finely divided lime 22 or the like, injected into the oxygen stream at a particulate injection point 40 between the oxygen supply source and the tuyere inlets 20.
  • a suspended particulate solid such as finely divided lime 22 or the like
  • the oxygen flows from the oxygen supply through a main oxygen supply line 24 and thence in succession through an orifice 26, a valve means, such as a flow control valve 28 (of the type Model Mark I Pneumatic Valve manufactured by Valtek Incorporated of Provo, Utah); an isolation control valve 30a (of the type Model l2OR manufactured by Jamesbury Corporation of Worchester, Massachusetts); a junction 32 with a branch nitrogen line 34; a junction 36 with another branch oxygen line 38; a junction 36' with still another branch oxygen line 38; a second isolation control valve 30b to the junction or particulate injection point 40 with an outlet line 42 containing the suspended lime 22 and thence through another now open control isolation valve 30b to the tuyere inlets 20.
  • a valve means such as a flow control valve 28 (of the type Model Mark I Pneumatic Valve manufactured by Valtek Incorporated of Provo, Utah); an isolation control valve 30a (of the type Model l2OR manufactured by Jamesbury Corporation of Worchester, Massachusetts); a junction 32 with a branch nitrogen line 34
  • the oxygen is supplied from the oxygen supply source to the tuyere inlet 20 at the predetermined oxygen flow rate R for refining the molten hot metal 13 into steel.
  • the pressure of the oxygen stream at the tuyere inlet 20 is controlled during non-injection periods at a value P which is about 3 to about 5 atmospheres less than the difference between the (about 12 to about 18 atmospheres) pressure of the oxygen supply source, and the oxygen pressure drop resulting from supplying the oxygen stream from the oxygen supply source to the tuyere inlets 20 which value P is greater than the minimum value at which the molten metal 18 will enter the tuyeres 16.
  • a lime injection loop or loops 44,44 are employed.
  • the control isolation valve b is closed and the oxygen stream flows through branch lines 38,38 through now open isolation control valves 300,300, check valves 46,46, now open isolation control valves 30d,30d' (of the type Model 120R manufactured by Jamesbury Corporation of Worcester, Massachusetts) into lime supply vessels 48,48 and containing the finely divided lime 22.
  • the oxygen stream passes through branch oxygen lines 50,50 and lime injection valves 52,52 (of the special Vee knotch type ball valve manufactured by Sunnyhill Manufacturing Company of Imperial, Pennsylvania),) nozzles 53,53 fed by lines a,50a' and thence into the lime outlet line 42 and through a now open isolation control valve 30e through the particulate solid junction 40 between the lime outlet line 42 and the main oxygen supply line 24.
  • the device 54 In order to sense the flow rate of the oxygen stream prior to the particulate injection point 40, the device 54 has a flow control means 55.
  • Such flow control means 55 has an oxygen flow sensing device 56 disposed across the orifice 26 for transmitting a flow signal through a line L1 to the input terminal e ofa flow con troller 58.
  • the oxygen flow sensing device 56 may be of the type 5, manufactured by Foxboro Corporation of Foxboro, Massachusetts, and the flow controller 58 may be a differential amplifier of the type P2 manufactured by Philbrick Incorporated, of Dedham, Massachusetts, which amplifier 58 performs the flow control function according to the equation:
  • e is the output voltage
  • e is the voltage input from the oxygen flow sensing device 56
  • e is the input voltage from a reference flow potentiometer 60.
  • This reference potentiometer 60 provides a reference signal which represents the desired flow rate of the oxygen stream through the orifice 26 in the main oxygen supply line 24 to provide the predetermined flow rate R1 of the oxygen stream and suspended lime 22 adjacent the tuyere inlets 20.
  • the output signal e,,; from the flow controller 58 is fed by line L5 to an input terminal e of a limiter 62, which limiter 62 is similar to the differential amplifier or flow controller 58.
  • an output signal from the limiter 62 is fed from output terminal e of the limiter 62 via line L6 to the valve means or control valve 28 to cause operation of such valve 28 to control the flow of the oxygen stream through the main oxygen supply line 24.
  • the flow sensing device 56 is a transmitter which generates an electrical signal which is proportional to the differential pressure across the orifice 26. This measured differential pressure is proportional to the oxygen flow through the orifice 26.
  • the voltage flow signal carried via line L]. to the input terminal e of the flow controller 58 is compared, of course, to the reference voltage signal from the reference flow potentiometer 60, and applied to input terminal e of the flow controller 58. If the flow of the oxygen stream through the orifice 26 should increase, the voltage signal carried via line L1 to the input terminal e, of the flow controller 58 increases, thereby causing an increase in the output voltage from output terminal c to input terminal e of the limiter 62. In turn, the voltage output from terminal e of the limiter 62 increases and is carried via line L6 to flow control valve 28 to move it to the closed position until the proper flow rate of the oxygen stream through the orifice 26 is established.
  • a pressure control device 57 is provided.
  • Pressure Control Device 57 Such device 57 has a pressure sensing device 64 disposed in the main oxygen supply line 24 just prior to the tuyere inlets 20.
  • This pressure sensing device 64 is of the type Model El lGM manufactured by Foxboro Corporation of Foxboro, Massachusetts and sends a voltage signal via line L2 to an input terminal e of a pressure controller 66.
  • the pressure controller 66 is a differential amplifier which is similar to the flow controller 58 and the limiter 62.
  • a pressure reference potentiometer 68 applies a reference pressure signal representing the desired pressure P1 of the oxygen stream at the tuyere inlets 20 to an input terminal 2 of the pressure controller 66.
  • the output signal from terminal e,,,, of the pressure controller 66 is fed via line L3 through a blocking device, such as the diode 70 or the like.
  • This blocking diode 70 is employed to permit the passage of only a positive output voltage from output terminal e of the pressure controller 66 to reach the input terminal e of the limiter 62 via line L4 between the: diode 70 and the limiter 62.
  • oxygen flow and pressure control device 54 functions to:
  • the hereinbefore mentioned nitrogen branch line 34 extends from its junction 32 from the main oxygen supply line 24 through a control isolation valve 30f to a junction 72 with a nitrogen supply line 74 extending from a nitrogen source 76 through a control isolation valve 30g to the shroud gas pipe 16a, concentric with the tuyeres 16.
  • valves 300, 30c, 30c, 30e are closed and valves 30]", 30b, and 3017' are open, nitrogen flows through lines 34, 24 to the tuyere inlets 20.
  • natural gas or the like flows from a natural gas source 80 through a control isolation valve 30h in a branch line 82 to a junction 84 with the line 74 and thence through the line 74 to the shroud gas pipes 78.
  • oxygen flow and pressure control apparatus 54' may also be utilized in conjunction with another orifice 28 and flow control valve 28 and oxygen flow sensing device 56' to control the flow and pressure of nitrogen through lines 34, 24 to the tuyeres.
  • the present invention may be employed with a bottom blown converter 210 having bottom submerged tuyeres 212, the side submerged tuyeres 214 and side tuyeres 216 directed toward the carbon monoxide zone (CO zone) of the converter 210.
  • This bottom blown converter 210 has a shell 218 provided with a refractory lining 220 and a mouth 222 and is rotatable on trunnions 224.
  • the tuyeres 212, 214, 216 are adapted to carry in an inner pipe 213 either a fluid alone, such as oxygen, air, argon, or mixtures thereof, or entrained pulverized additives therein, such as a fluxing agent (burned lime (CaO) or the like),- a liquefying agent (fluorspar (CaF or the like), or a blocking or deoxidizing agent (ferro manganese or the like), and in an outer pipe 215 a shroud gas, such as propane, natural gas, light fuel oil or the like.
  • a fluxing agent burned lime (CaO) or the like
  • fluorspar fluorspar
  • fluoro manganese or the like a blocking or deoxidizing agent
  • the present invention is also applicable to a Heroult Type electric-arc steelmaking furnace 210a provided with a vertical and inclined bottom submerged tuyere 212a and 212a, side submerged tuyeres 214a, and a side tuyere 216a directed toward the carbon monoxide zone (CO zone) of the furnace 210a.
  • This electric arc steelmaking furnace 210a has a shell 218a provided with a refractory lining 220a, a side door 226, a refractory roof 228 provided with electrode holes 230, a tap hole 232, and a pouring spout 234 extending from the tap hole 232.
  • the tuyeres 212 and 212a, 214a, 216a are adapted to carry in an inner pipe 213 either a fluid alone, such as oxygen, air, argon, or mixtures thereof, or entrained pulverized additives therein, such as a fluxing agent (burned lime (CaO) or the like), a liquefying agent, (fluorspar (CaF or the like), or a blocking or deoxidizing agent (ferro manganese or the like), and in an outer pipe 215, a shroud gas, such as propane, natural gas, light fuel oil or the like.
  • a fluxing agent burned lime (CaO) or the like
  • fluorspar fluorspar
  • a blocking or deoxidizing agent ferrro manganese or the like
  • a shroud gas such as propane, natural gas, light fuel oil or the like.
  • the present invention may be employed as shown in FIG. 4 with the open hearth furnace 2l0b having the vertical and inclined bottom submerged tuyeres 212b and 21212, the side submerged tuyere 214b, and the side tuyere 216b directed toward the carbon monoxide zone (CO zone) of the furnace 21017.
  • This open hearth furnace 210b includes a refractory lined bottom 236, a refractory lined sloping back wall 238, a refractory lined front wall 240, a charging door 242 in the wall 240, and a refractory lined roof 244.
  • a tap hole 232b opposite the charging door 242 leads to a pouring spout 234b.
  • the tuyeres 212b, 2l2b, 214b, 21617 are adapted to carry in an inner pipe 213 either a fluid alone, such as oxygen, air, argon, or mixtures thereof, or entrained pulverized additives therein, such as a fluxing agent (burned lime (CaO) or the like), a liquefying agent (fluorspar (CaF or the like), or a blocking or deoxidizing agent (ferro manganese or the like), and in an outer pipe 215, a shroud gas, such as propane, natural gas, light fuel oil or the like.
  • a fluxing agent burned lime (CaO) or the like
  • fluorspar fluorspar
  • a blocking or deoxidizing agent ferrro manganese or the like
  • a shroud gas such as propane, natural gas, light fuel oil or the like.
  • the present invention may be employed with a tilting open hearth furnace 2100 mounted on rollers 246 arranged in a circular path for providing rotation on the longitudinal axis of the furnace 210C for pouring the refined steel through a tap hole 232a and a pouring spout 234C.
  • the tiltable open hearth furnace 210c has vertical and inclined bottom submerged tuyeres 212C and 2120' connected through a blast box 248 to the lines and 74 shown in FIG. 1.
  • a submerged side tuyere 214C and a side tuyere 2166 directed toward the carbon monoxide zone (CO zone) of the furnace 2106 are employed.
  • the tiltable open hearth furnace 2100 has a refractory lined bottom 236C, refractory lined back wall 238C, refractory lined front wall 2406 (provided with a charging door 242C) and a refractory lined roof 244C.
  • the tuyeres 212e, 212a, 214C, 2160 are adapted to carry in an inner pipe 213 either a fluid alone, such as oxygen, air, argon, or mixtures thereof, or entrained pulverized additives therein, such as a fluxing agent (burned lime (CaO) or the like), a liquefying agent (fluorspar (CaF or the like), or a blocking or deoxidizing agent (ferro manganese or the like), and in an outer pipe 215, a shroud gas, such as propane, natural gas, light fuel oil or the like.
  • a fluxing agent burned lime (CaO) or the like
  • fluorspar fluorspar
  • a blocking or deoxidizing agent ferrro manganese or the like
  • a shroud gas such as propane, natural gas, light fuel oil or the like.
  • the present invention is employed with a hot metal mixer 210d having .a shell 218d provided with a refractory lining 220d, and having also an inlet mouth 222d and a pouring spout 234d.
  • the mixer 210d is oscillatable on rollers 246d between the charging and discharging positions.
  • Such mixer 2l0d has vertical and inclined bottom submerged tuyere 2l2d,2l2d, side submerged tuyeres 214d, and side tuyere 216d directed toward the carbon monoxide zone (CO zone) of the mixer 210d.
  • the tuyeres 212-d, 212d, 214d, 216d are adapted to carry in an inner pipe 213 either a fluid alone, such as oxygen, air, argon, or mixtures thereof, or entrained pulverized additives therein, such as a fluxing agent (burned lime (CaO) or the like), a liquefying agent (Fluorspar (CaF or the like), or a blocking or deoxidizing agent (ferro manganese or the like), and in an outer pipe 215, a shroud gas, such as propane, natural gas, light fuel oil or the like.
  • a discharge tuyere or tuyeres 32 (FIGS. 2,3,4,5,6) is disposed adjacent a discharge opening such as the mouth 222 (FIG. 2); the pouring spouts 234 (FIG. 3); 234b (FIG. 4); 234C (FIG. 5); and 234d (FIG. 6) to prevent the formation of skulls adjacent or on the discharge opening during the pouring operation particularly those chromium-nickel skulls produced during the refining of stainless steel.
  • the method includes the steps of:
  • the pressure override portion 57 of the oxygen flow and pressure control apparatus 54 includes in the improved method the additional steps of:
  • the improved method also includes the additional step of:
  • a blocking device 70 blocking by means of a blocking device 70 the output signal of the output terminal e,,,, of the pressure controller 66 to the input terminal e of the flow limiter 62 when the pressure of the oxygen stream at the tuyere inlets 20 is greater than the desired pressure P1 of the oxygen stream at such tuyere inlets 20.
  • a. operates below sonic velocities (Mach 1.0) and in a subsonic range near 01-08 of Mach 1.0 velocity); b. will maintain the oxygen flow rate R, constant throughout the blowing period and in particular, during the fluxing period when finely divided lime 22 is being injected through the tuyeres l6 and in addition, when such lime is not being injected into such tuyeres 16; and c. will prevent transient pressure changes at tuyere inlets 20 particularly during the starting and stopping of flux injection from dropping below a minimum pressure level Pl thereby preventing the molten hot metal 18 from entering the tuyeres 16.
  • amain oxygen supply line connecting said gas supply source to said tuyere inlet for supplying said gas stream to said tuyere inlet at said predetermined flow rate for refining said iron base melt;
  • injection means for suspending said suspended particulate solid in said gas stream and for injecting said suspended particulate solid at a particulate injection point in said main oxygez supply line prior to entry of said gas stream and said suspended particulate solid into said tuyere inlet thereby increas ing said pressure drop of said gas stream from said gas supply source to said tuyere inlet as a result of the passage of said gas stream and said suspended particulate solid through said injection means and said main oxygen supply line;
  • flow control means connected to said main oxygen supply line prior to said particulate injection point for sensing the flow of said gas stream through said main oxygen supply line;
  • valve means connected to said flow control means and in communication with said main oxygen supply line prior to said particulate injection point for controlling the flow of said gas stream through said main oxygen supply line;
  • said flow control means being operable to adjust said valve means in said main oxygen supply line to maintain substantially constant said predetermined flow rate of said gas stream and said suspended particulate solid to said tuyere inlet.
  • pressure control means has:
  • a. pressure sensing means for sensing the pressure of said gas stream adjacent said tuyere inlet to create a pressure signal
  • a pressure controller connected to said pressure sensing means and adapted to receive said pressure signal from said pressure sensing means.
  • said pressure controller operable to compare said pressure signal with a reference pressure signal representing the desired pressure of said gas stream at said tuyere inlet;
  • a flow limiter connected to said pressure controller and adapted to receive an output signal from said pressure controller
  • said flow limiter being operable to apply an output signal from said flow limiter to said valve means to adjust said valve means to permit a flow rate of said gas stream through said valve means which will produce the desired pressure of said gas stream at said tuyere inlet.
  • blocking means disposed between said pressure controller and said flow limiter for blocking said output signal from said pressure controller to said flow limiter when the pressure of said gas stream at said tuyere inlet is greater than said desired pressure of said gas stream at said tuyere inlet.
  • flow sensing means in communication with said main oxygen supply line for sensing the flow rate of said gas stream prior to said particulate injection point and to create a flow signal; and i b. a flow controller connected to said flow sensing means and adapted to receive said flow signal from said flow sensing means.
  • said flow control means adapted to compare said flow signal with a reference signal representing the desired flow rate of said gas stream;
  • said flow controller being operable to apply an output flow signal to said flow limiter
  • said flow limiter being operable to apply an output flow signal from said flow limiter to said valve means to adjust said valve means to permit passage of the desired flow return of said gas stream to said flow control means.
  • said gas supply means has a pressure from about 12 to about 18 atmospheres.
  • said gas stream is an oxygen stream.
  • said main oxygen supply line maintains substantially constant said predetermined flow rate at said tuyere inlet at a flow velocity of between 0.7 to
  • said flow control means maintains the pressure of said gas stream during non-injection periods so that the pressure of said gas stream at said tuyere inlet is from about 3 atmospheres to about 5 atmospheres less than the difference between said super atmospheric pressure of said gas supply source and the pressure drop in said gas stream resulting from the passage of said gas stream through said main oxygen supply line.
  • said suspended particulate solid is finely divided lime.
  • said gas stream is nitrogen.

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  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
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  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
US309037A 1972-07-27 1972-11-24 Apparatus for and method of refining an iron base melt Expired - Lifetime US3897047A (en)

Priority Applications (15)

Application Number Priority Date Filing Date Title
US309037A US3897047A (en) 1972-07-27 1972-11-24 Apparatus for and method of refining an iron base melt
YU01831/73A YU183173A (en) 1972-07-27 1973-07-03 Process for the purification of melt iron
JP8276873A JPS5729528B2 (da) 1972-07-27 1973-07-24
HUUE39A HU167535B (da) 1972-07-27 1973-07-26
IT27218/73A IT995081B (it) 1972-07-27 1973-07-27 Apparato e metodo per affinare una colata a base di ferro
LU68115A LU68115A1 (da) 1972-07-27 1973-07-27
FR7327682A FR2194784B1 (da) 1972-07-27 1973-07-27
CA177,498A CA993195A (en) 1972-07-27 1973-07-27 Apparatus for and method of refining an iron base melt
NL7310470A NL7310470A (da) 1972-07-27 1973-07-27
ES417320A ES417320A1 (es) 1972-07-27 1973-07-27 Procedimiento y aparato para refinar una calda a base de hierro.
GB3587573A GB1456977A (en) 1972-07-27 1973-07-27 Apparatus for and method of refining an iron base melt
AT662073A AT341557B (de) 1972-07-27 1973-07-27 Verfahren und vorrichtung zum frischen eines flussigen eisen- bzw. roheiseneinsatzes
SE7310431A SE426344B (sv) 1972-07-27 1973-07-27 Sett och anordning for reglering av en gasstrom vid inblasning av partikelformigt material under ytan av en smelta pa jernbas
DE2338241A DE2338241C2 (de) 1972-07-27 1973-07-27 Vorrichtung und Verfahren zum Frischen einer Metallschmelze
US05/524,104 US3970446A (en) 1972-11-24 1974-11-15 Method of refining an iron base melt

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US27584872A 1972-07-27 1972-07-27
US309037A US3897047A (en) 1972-07-27 1972-11-24 Apparatus for and method of refining an iron base melt

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US27584872A Continuation-In-Part 1972-07-27 1972-07-27

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US3897047A true US3897047A (en) 1975-07-29

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US (1) US3897047A (da)
JP (1) JPS5729528B2 (da)
AT (1) AT341557B (da)
CA (1) CA993195A (da)
DE (1) DE2338241C2 (da)
ES (1) ES417320A1 (da)
FR (1) FR2194784B1 (da)
GB (1) GB1456977A (da)
HU (1) HU167535B (da)
IT (1) IT995081B (da)
LU (1) LU68115A1 (da)
NL (1) NL7310470A (da)
SE (1) SE426344B (da)
YU (1) YU183173A (da)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4045213A (en) * 1974-11-28 1977-08-30 Creusot-Loire Method of injecting a powder containing carbon into a metal bath
US4050681A (en) * 1973-05-25 1977-09-27 Eisenwerk-Gesellschaft Maximilianshutte Mbh Apparatus for the controlled feeding of a refining gas and of a fluid protective medium
US4136857A (en) * 1973-03-30 1979-01-30 United States Steel Corporation Method and apparatus for automatically controlling the rate of flux injection to a converter
US4264059A (en) * 1980-03-12 1981-04-28 Victor Benatar Condition responsive control means for use in discharging powdered reagent into a pool of molten metal
CN107489886A (zh) * 2017-09-29 2017-12-19 四川德胜集团钒钛有限公司 一种冶金工业氧气控制系统

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE447911B (sv) * 1977-05-04 1986-12-22 Maximilianshuette Eisenwerk Sett vid framstellning av stal i konverter
JPS6062018U (ja) * 1983-10-03 1985-04-30 本州製紙株式会社 組立段ボ−ル箱
JPH01164118U (da) * 1988-05-06 1989-11-16

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Publication number Priority date Publication date Assignee Title
US327425A (en) * 1885-09-29 Steel plant
US707776A (en) * 1901-08-21 1902-08-26 Electro Metallurg Francaise Soc Oscillating electric furnace.
US2906617A (en) * 1955-05-14 1959-09-29 Siderurgie Fse Inst Rech Method for a thorough desulfurizing of molten metal and in particular of liquid pig iron
US3034887A (en) * 1959-06-11 1962-05-15 Leonard M Cohn Process for making steel
US3330645A (en) * 1962-08-07 1967-07-11 Air Liquide Method and article for the injection of fluids into hot molten metal
US3397878A (en) * 1965-11-19 1968-08-20 Union Carbide Corp Under-bath tuyere
US3598386A (en) * 1967-10-09 1971-08-10 Crucible Steel Co America Apparatus for making steel

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FR2182688A1 (en) * 1972-05-04 1973-12-14 Creusot Loire Blowing nozzle - with concentric pipes

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US327425A (en) * 1885-09-29 Steel plant
US707776A (en) * 1901-08-21 1902-08-26 Electro Metallurg Francaise Soc Oscillating electric furnace.
US2906617A (en) * 1955-05-14 1959-09-29 Siderurgie Fse Inst Rech Method for a thorough desulfurizing of molten metal and in particular of liquid pig iron
US3034887A (en) * 1959-06-11 1962-05-15 Leonard M Cohn Process for making steel
US3330645A (en) * 1962-08-07 1967-07-11 Air Liquide Method and article for the injection of fluids into hot molten metal
US3397878A (en) * 1965-11-19 1968-08-20 Union Carbide Corp Under-bath tuyere
US3598386A (en) * 1967-10-09 1971-08-10 Crucible Steel Co America Apparatus for making steel

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4136857A (en) * 1973-03-30 1979-01-30 United States Steel Corporation Method and apparatus for automatically controlling the rate of flux injection to a converter
US4050681A (en) * 1973-05-25 1977-09-27 Eisenwerk-Gesellschaft Maximilianshutte Mbh Apparatus for the controlled feeding of a refining gas and of a fluid protective medium
US4045213A (en) * 1974-11-28 1977-08-30 Creusot-Loire Method of injecting a powder containing carbon into a metal bath
US4264059A (en) * 1980-03-12 1981-04-28 Victor Benatar Condition responsive control means for use in discharging powdered reagent into a pool of molten metal
CN107489886A (zh) * 2017-09-29 2017-12-19 四川德胜集团钒钛有限公司 一种冶金工业氧气控制系统

Also Published As

Publication number Publication date
AT341557B (de) 1978-02-10
JPS49123920A (da) 1974-11-27
ES417320A1 (es) 1976-06-01
SE426344B (sv) 1982-12-27
LU68115A1 (da) 1973-10-03
CA993195A (en) 1976-07-20
YU183173A (en) 1982-02-28
IT995081B (it) 1975-11-10
GB1456977A (en) 1976-12-01
JPS5729528B2 (da) 1982-06-23
FR2194784A1 (da) 1974-03-01
DE2338241A1 (de) 1974-02-07
FR2194784B1 (da) 1982-05-07
HU167535B (da) 1975-10-28
ATA662073A (de) 1977-06-15
DE2338241C2 (de) 1984-08-09
NL7310470A (da) 1974-01-29

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

Effective date: 19880112