WO2011073760A1 - Injection device and relative operative method - Google Patents

Injection device and relative operative method Download PDF

Info

Publication number
WO2011073760A1
WO2011073760A1 PCT/IB2010/003218 IB2010003218W WO2011073760A1 WO 2011073760 A1 WO2011073760 A1 WO 2011073760A1 IB 2010003218 W IB2010003218 W IB 2010003218W WO 2011073760 A1 WO2011073760 A1 WO 2011073760A1
Authority
WO
WIPO (PCT)
Prior art keywords
feed pipe
fluid
fed
injection
exit
Prior art date
Application number
PCT/IB2010/003218
Other languages
French (fr)
Inventor
Daniele Tolazzi
Claudio Candusso
Original Assignee
More Srl
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 More Srl filed Critical More Srl
Publication of WO2011073760A1 publication Critical patent/WO2011073760A1/en

Links

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
    • C21C5/52—Manufacture of steel in electric furnaces
    • C21C5/5211—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace
    • C21C5/5217—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace equipped with burners or devices for injecting gas, i.e. oxygen, or pulverulent materials into the furnace
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/16—Introducing a fluid jet or current into the charge
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D3/00—Charging; Discharging; Manipulation of charge
    • F27D3/18—Charging particulate material using a fluid carrier
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0001—Heating elements or systems
    • F27D99/0003—Heating elements or systems with particulate fuel, e.g. aspects relating to the feeding
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0001—Heating elements or systems
    • F27D99/0005—Injecting liquid fuel
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D99/00—Subject matter not provided for in other groups of this subclass
    • F27D99/0001—Heating elements or systems
    • F27D99/0033—Heating elements or systems using burners
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/20—Recycling

Definitions

  • the present invention concerns an injection device usable in electric furnaces for producing steel, and able to inject at supersonic speed at least a stream of one or more fluids and/or solids used during the melting process and the subsequent refining of a metal charge.
  • the injection device according to the present invention is used effectively in different operating modes, both to inject fluids and to inject solids and to give rise to a flame able to heat and melt the metal charge.
  • the present invention also concerns the method for the functioning of the injection device, in particular its different modes of use in the various operating steps.
  • Injection devices used in electric arc furnaces are known, and in other applications in the steel and metallurgical industry, to inject gases and liquid and/or solid fuels, using lances or other types of devices, above and inside the melting metal bath.
  • Injection devices are also known suitable to inject the gases at supersonic speed, to obtain a high yield in the injection operations.
  • Burner devices are also known, which act on the scrap, in particular immediately after it has been unloaded into the furnace, in order to cause and/or accelerate the melting thereof.
  • injection devices are mounted on the walls of the furnace putting the end, or emitter nozzle, far from the metal bath, so as to preserve their integrity with respect to the deteriorating agents, such as the extremely high temperature, the splashes of molten metal and/or slag, corrosion, and impacts with the solid charge.
  • This functioning condition necessarily entails the use of a flame also during the supersonic injection of a fluid and/or solid, causing an increase in the consumption of comburent and combustible gas during the process.
  • One purpose of the present invention is to achieve an injection device, without a pre-mixing chamber, which is easy and economical to make, which allows to reduce the times and costs of installation, management and maintenance, and which can be brought near to the zone of impact in the metal bath, reducing to a minimum the risk that parts of the injection device are subjected to splashes of molten metal and/or slag, corrosion and impacts due to the metal charge.
  • Another purpose of the present invention is to perfect a method which allows to reduce the times and costs of installation, management and maintenance, and which allows to bring the injection device near the zone of impact in the metal bath, reducing to a minimum the risk that parts of the injection device are subjected to splashes of molten metal and/or slag, corrosion and impacts due to the metal charge.
  • the Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
  • an injection device is applied to inject one or more fluids and/or solids inside a furnace for melting a metal charge and comprises a cooled main body provided with a plurality of feed pipes, to feed fluids and/or solids into it.
  • the injection device also comprises first injection means mounted on the main body and suitable to inject at supersonic speed a stream of a first fluid, for example air or oxygen, in the direction of the metal bath.
  • first injection means mounted on the main body and suitable to inject at supersonic speed a stream of a first fluid, for example air or oxygen, in the direction of the metal bath.
  • the injection device comprises second injection means, also mounted on the main body in a position adjacent and separate with respect to the first injection means, and suitable to inject a second fluid and/ or a solid, the latter for example in the form of particulate, in the direction of the metal bath.
  • the injection device also comprises burner means, also mounted on the main body and having one or more emission pipes disposed externally and around both the first injection means and the second injection means, so as to define, substantially, one or more crowns around them.
  • Each emission pipe is fed by a first feed pipe to feed a combustible, comburent or inert fluid, and by a second pipe to feed a comburent or inert fluid.
  • the injection device comprises first valve means able to intercept one and/or the other of the combustible and comburent fluids in order to selectively interrupt the feed to the emission pipes at least of the first injection means and the burner means, and second valve means, drivable alternatively to said first valve means, to feed cleaning and/or protection fluids through at least said first injection means and said burner means, so as to keep the pipes clean of detritus and/or slag.
  • the present invention it is possible to selectively exclude the feed of the combustible and comburent fluid to the emission pipes of the first injection means and burner means, so as to prevent the formation of the flame, but in any case maintaining the delivery of a fluid, for example compressed air, inert gas or other suitable fluid, for the sole purpose of guaranteeing emission pipes that are free of slag or steel residues.
  • a fluid for example compressed air, inert gas or other suitable fluid
  • the switching of the fluid delivered is achieved by closing the first valve means disposed along a relative feed line, the so-called main feed line, and by opening second valve means in order to render a second feed line operative, the so-called auxiliary feed line, so as to keep the respective lines independent of each other and to allow a correct management of the respective emissions.
  • the burner means can selectively emit either a flame or a jet of comburent gas, or a jet of compressed air, or a jet of inert gas, in any case so as to form a protective screen to convey the streams of fluids and/or solids injected into the liquid bath, preserving and protecting the first and second injection means from possible occlusions and preventing dispersions of the fluids and/or solids injected into the atmosphere of the furnace.
  • the stream injected at supersonic speed by the first injection means in fact contributes to conveying the stream injected by the second injection means inside the layer of slag separated from the bath, preventing it from being dispersed into the atmosphere of the furnace.
  • the reciprocally adjacent position of the first injection means and the second injection means allows to exploit the fluid injected by the first injection means so as to keep the second injection means free from possible occlusions caused by splashes of slag and/or liquid metal, and to prevent, as happens in current equipment, the need to use another jet of oxygen or a flame, to achieve the same purpose.
  • both the first injection means and the second injection means comprise an injection terminal conformed specifically for the operating conditions and the fluids and/or solids to be injected.
  • the injection terminal of the first injection means comprises at least a segment having a section useful for the passage of the fluid, which section has limited dimensions with respect to the remaining part, so as to allow to modify, also at different points, the fluid-dynamic conditions of the passage of the fluid through the terminal, and to determine the injection at supersonic speed.
  • the first injection means comprise at least a first nozzle, while the second injection means comprise a second nozzle.
  • the longitudinal axes of the two nozzles are parallel to each other and lie on the same plane.
  • the lying plane common to the two longitudinal axes of the nozzles is substantially vertical.
  • the lying plane common to the two longitudinal axes of the nozzles is substantially horizontal.
  • the lying plane common to the two longitudinal axes of the nozzles is inclined with respect to ideal horizontal and vertical references.
  • the burner means comprise two distinct types of emission pipes, a first defining an internal crown, and a second defining an external crown.
  • the emission pipes that define the internal crown are substantially parallel to each other and to a longitudinal axis of the injection device.
  • the emission pipes that define the external crown are inclined on two axes with respect to a median longitudinal axis of the injection device, to deliver the relative jet of fluid with a tangential component that facilitates the mixing of the fluids between the two emission pipes.
  • FIG. 1 is a schematic lateral view of an injection device according to the present invention.
  • - fig. 2 is a schematized front view of the injection device in fig. 1;
  • - fig. 3 is a section from III to III of fig. 2;
  • - fig. 4 is a section from IV to IV of fig. 2;
  • - fig. 5 is a variant of fig. 4;
  • - fig. 6 is a section from V to V of fig. 2;
  • - fig. 7 is a diagram of a feed unit of the injection device in fig. 1.
  • the reference number 10 denotes in its entirety an injection device according to the present invention.
  • the injection device 10 is advantageously but not exclusively applied in the steps of injecting comburent and/or refining fluids, during the melting of a metal alloy, in which scrap metal and other materials, for example carbon, that make up the alloy, are made to melt in an electric furnace inside a liquid bath.
  • the injection device 10 comprises, generally, a main body 1 1 substantially cylindrical in shape and without a pre-mixing chamber, a first injection nozzle
  • the injection device 10 also comprises a feed unit 32, disposed upstream of the main body 1 1 and able to feed the injection nozzles 16 and 19 with fluids and/or solids, and the burner unit 29, depending on programmed or programmable operating conditions.
  • the main body 1 1 comprises a plurality of connection pipes, of which the specific functions will be described in more detail hereafter, which branch off from the external surface of the main body 1 1 so as to connect the main body 1 1 to the feed unit 32, in order to feed the fluids and/or solids used by the injection device during the process.
  • the main body 1 1 is also equipped with pipes able to guarantee the passage of a cooling fluid, both in an external cooling chamber 46 and also in internal cooling chambers 47.
  • the first injection nozzle 16 is suitable for the passage of a fluid and is made inside the main body 1 1 , in a condition substantially parallel to a longitudinal axis of the main body 1 1.
  • the first injection nozzle 16 comprises a rear end fluidically connected to a relative feed pipe 16a through which the feed unit 32 feeds a relative fluid, for example a gas, and a front end constrained to an injection terminal 17.
  • a relative fluid for example a gas
  • the injection terminal 17 has a segment with a reduced section, to vary the fluid-dynamic conditions of passage of the fluid and to determine the supersonic speed injection.
  • the internal section of the injection terminal 17 is for example of the type known as "De-Laval nozzle", to accelerate a fluid from a subsonic speed to a supersonic speed.
  • the second injection nozzle 19 is functionally suitable to allow the passage inside it of both gassy substances and of solid particulate, and is substantially parallel to the longitudinal axis of the main body 1 1.
  • This positioning takes the second injection nozzle 19 to a position substantially parallel and adjacent to the first injection nozzle 16, so that the respective longitudinal axes of the two nozzles 16 and 19 lie on the same plane.
  • the plane on which the longitudinal axes of the two nozzles 16 and 19 lie is substantially vertical and also comprises the median longitudinal axis of the main body 11.
  • the plane is disposed substantially horizontal, or inclined with respect to the traditional horizontal and vertical references.
  • the two nozzles 16 and 19 are disposed substantially parallel to each other, but in non-symmetrical conditions with respect to the median longitudinal axis of the main body 1 1.
  • the second injection nozzle 19 also comprises an injection terminal 20 through which the fluid and/or solid to be injected into the liquid bath is delivered.
  • the second injection nozzle 19 also comprises, integrated therewith, in the rear part, a feed pipe 19a, through which the feed unit 32 feeds the gas and/or the solid particulate provided for injection.
  • the burner unit denoted in its entirety by the reference number 29, comprises two series of emission pipes 22 and 23, open toward the front surface of the main body 1 1, that is, the surface through which the two injection nozzles 16 and 19 open toward the outside.
  • the series of nozzles 22 and 23 of the burner unit 29 define two distinct crowns, respectively internal 30 and external 31, both external and surrounding the injection nozzles 16 and 19.
  • the internal crown 30, consisting of a series of nozzles 22 disposed circularly around the two injection nozzles 16 and 19 and substantially parallel to each other, is connected to a feed pipe 30a.
  • the feed pipe 30a is open on one side toward the respective nozzles 22 and, through these, toward the front surface; on the other side it is connected to the feed unit 32.
  • the feed unit 32 can feed the nozzles 22, and hence the internal crown 30, with a combustible fluid, or with a cleaning fluid, such as compressed air, or with an inert gas.
  • the external crown 3 1 consisting of a series of nozzles 23 disposed circularly around the two injection nozzles 16 and 19 and inclined on two axes with respect to a plane passing through the median longitudinal axis of the main body 1 1, is connected to a main feed pipe 31a.
  • the nozzles 23 are oriented in such a manner as to impart to the jet delivered a tangential component, called "SWIRL", thus promoting the rapid mixing of the reagents and the stability of the flame, even in the absence of a pre-mixing chamber.
  • the feed pipe 31a is open on one side, toward the respective nozzles 23 and, through the latter, toward the front surface, and on the other side is connected to the feed unit 32.
  • the feed unit 32 can feed, through the pipe 3 1a, the nozzles 23 and hence the crown 31, with a comburent fluid or with a cleaning fluid or with inert gas.
  • each nozzle 23 has a first angle of inclination a with respect to a plane passing through the longitudinal axis of the main body 1 1 and the axis of the corresponding nozzle 22, and a second angle of inclination ⁇ again with respect to the axis of the corresponding nozzle 22.
  • the first angle of inclination a has values preferably comprised between about 0° and about 90°, while the second angle of inclination ⁇ has values preferably comprised between about 0° and about 80°.
  • the two nozzles 22 and 23 do not directly protrude from the front surface of the main body 1 1 of the injection device 10, but face each other in a common chamber 27.
  • the depth of the chamber 27 may be made as desired, depending on specific operating requirements.
  • each nozzle 23 of the external crown 31 preferably has its longitudinal axis lying on the plane passing through the axis of the corresponding nozzle 22 of the internal crown and inclined by the first angle of inclination a with respect to the plane passing through the longitudinal axis of the main body 1 1 and the longitudinal axis of the nozzle 22.
  • each nozzle 23 has its longitudinal axis offset by an amount X with respect to the plane passing through the axis of the corresponding nozzle 22.
  • the two crowns 30 and 31 are disposed circularly around the injection nozzles 16 and 19, it is possible to create a screen formed by the fluids exiting from the two crowns 30 and 31 to convey the fluids and particulate injected through the two nozzles 16 and 19 toward the layer of slag, and prevent dispersions thereof into the atmosphere of the furnace 1 1.
  • the feed unit 32 shown schematically in fig. 7, comprises a command and control unit 33, a unit to manage and feed the fluids 35, and a unit to manage and feed the solids 36.
  • the command and control unit 33 is of a substantially known type, such as for example a PLC processor (Programmable Logic Control), a CNC processor (Computer Numerical Control) or other, and is connected electronically both to the management and feed unit 35 and also to the management and feed unit 36, so as to command the various deliveries and feeds through the relative main feed pipes 16a, 19a, 30a and 31a.
  • a PLC processor Programmable Logic Control
  • CNC processor Computer Numerical Control
  • the management and feed unit 35 provides, associated therewith, the feed pipes 16a, 30a and 31a.
  • the management and feed unit 35 also comprises the auxiliary feed pipes 37, 41 and 44, the first interception valves 39, 42 and 45, disposed along the main emission lines, and the second interception valves 40, 43 and 46 disposed along the auxiliary emission lines.
  • the auxiliary feed pipe 37 is fluidically connected to the feed pipe 30a, upstream of the inlet to the crown 30, but downstream of the interception valve 39, with respect to the direction in which the fluid flows.
  • a cleaning fluid for example compressed air, or an inert gas, may selectively be made to flow through the auxiliary feed pipe 37.
  • the first interception valve 39 is fluidically connected to the feed pipe 30a, upstream of the connection zone between the feed pipe 30a and the auxiliary feed pipe 37.
  • the first interception valve 39 selectively conditions the passage of the fluid fed by the feed pipe 30a.
  • the second interception valve 40 is fluidically associated with the auxiliary feed pipe 37, upstream of the connection zone between the auxiliary feed pipe 37 and the feed pipe 30a.
  • the second interception valve 40 selectively conditions the passage of the fluid fed by the auxiliary feed pipe 37.
  • Both the first interception valve 39 and the second interception valve 40 are electronically commanded by the command and control unit 33, so as to allow the passage of the fluid through the relative feed pipe, main 30a or auxiliary 37, alternately.
  • a combustible fluid such as methane
  • a cleaning fluid such as compressed air, or an inert gas which, mixed with the cleaning fluid or inert gas exiting from the external crown 31, determines a fluidic protection barrier for the injection nozzles 16 and 19.
  • the auxiliary feed pipe 44 is fluidically connected to the feed pipe 31a, upstream of the inlet to the crown 31 , with respect to the direction in which the fluid flows.
  • a cleaning fluid such as compressed air, or an inert gas, is made to flow through the auxiliary feed pipe 44.
  • the first interception valve 45 is fluidically associated with the feed pipe 31a, upstream of the connection zone between the feed pipe 31a and the auxiliary feed pipe 44.
  • the first interception valve 45 selectively conditions the passage of the fluid fed by the feed pipe 31 a.
  • the second interception valve 46 is fluidically associated with the auxiliary feed pipe 44 upstream of the connection zone between the auxiliary feed pipe 44 and the feed pipe 31 a.
  • the second interception valve 46 selectively conditions the passage of the fluid fed by the auxiliary feed pipe 44.
  • Both the first interception valve 45 and the second interception valve 46 are electronically commanded by the command and control unit, so as to allow the passage of the fluid through the relative feed pipe, main 31a or auxiliary 44, alternately.
  • a comburent fluid for example pure oxygen
  • a cleaning fluid such as compressed air or an inert gas which, mixed with the cleaning fluid or inert gas exiting from the internal crown 30, determines a fluidic protection barrier for the injection nozzles 16 and 19.
  • auxiliary feed pipe 41 is fluidically connected to the feed pipe 16a, upstream of the inlet to the injection nozzle 16, with respect to the direction in which the fluid flows.
  • a cleaning fluid such as compressed air, or an inert gas is made to flow through the auxiliary feed pipe 41.
  • the first interception valve 42 is fluidically associated with the feed pipe 16a, upstream of the connection zone between the feed pipe 16a and the auxiliary feed pipe 41.
  • the first interception valve 42 selectively conditions the passage of the fluid fed by the feed pipe 16a.
  • the second interception valve 43 is fluidically associated with the auxiliary feed pipe 41 upstream of the connection zone between the auxiliary feed pipe 41 and the feed pipe 16a.
  • the second interception valve 43 selectively conditions the passage of the fluid fed by the auxiliary feed pipe 41.
  • Both the first interception valve 42 and the second interception valve 43 are electronically commanded by the command and control unit 33, so as to allow the passage of the fluid through the relative feed pipe, main 16a or auxiliary 41, alternately.
  • the injection nozzle 16 it is possible to deliver alternately a comburent fluid, and hence facilitate the refining of a metal alloy during the melting steps inside an electric furnace, or a cleaning fluid, such as compressed air, or an inert gas, with the sole purpose of keeping the injection nozzle 16 free from possible occlusions caused by splashes of slag and/or liquid metal.
  • the management and feed unit 36 provides, associated therewith, the feed pipe 19a, fluidicially connected with the nozzle 19 to allow the passage inside it of both gassy substances and solid particulate.
  • the main body 1 1 is equipped with two chambers, inside which a cooling fluid is made to circulate, preferentially water, with the purpose of guaranteeing the integrity of the device when exposed to the extremely high temperatures registered inside the electric furnace for melting metals.
  • the first chamber 46, or external chamber is fluidically connected with an inlet pipe 46a of the cooling fluid and with an exit pipe 46b, through which the fluid exits.
  • the second chamber 47, or internal chamber is fluidically connected with an inlet pipe 47a of the cooling fluid and with an exit pipe 47b, through which the fluid exits.
  • the injection device 10 In a first operating mode of the injection device 10, it functions as a burner, to heat the iron scrap before the latter sinks completely into the liquid bath inside the furnace.
  • comburent fluid is fed through the feed pipe 31a to exit through the external crown 31 ;
  • combustible fluid is fed through the feed pipe 30a to exit through the internal crown 30;
  • a cleaning fluid for example compressed air, or an inert gas is fed through the feed pipe 16a to exit through the first injection nozzle 16;
  • a cleaning fluid for example compressed air, or an inert gas is fed through the feed pipe 19a to exit through the second injection nozzle 19.
  • the command and control unit 33 keeps the (first) interception valves 39 and 45 in an open operating condition, allowing the respective combustible and comburent fluids to pass through the feed pipes 30a and 31a.
  • the command and control unit 33 keeps the (second) interception valves 40 and 46 in a closed operating condition, preventing the passage of cleaning fluid or inert, generally compressed air, through the auxiliary feed pipes 37 and 44.
  • the command and control unit keeps the interception valve 42 in a closed operating condition, preventing the passage of the comburent fluid, generally oxyen, through the feed pipe 16a.
  • the command and control unit 33 keeps the interception valve 43 in an open operating condition, allowing a cleaning fluid, generally compressed air, to pass through the auxiliary feed pipe 41.
  • the stream of cleaning fluid or inert injected by the first injection nozzle 16 does not reach high speeds, and its only function is to keep the injection nozzle 16 clean.
  • the injection device 10 In a second operating mode of the injection device 10 according to the present invention it functions as a supersonic injector of a comburent fluid.
  • This operating mode is applied particularly during the melting and refining steps of the metal in formation.
  • a cleaning fluid or inert for example compressed air, is fed through the auxiliary feed pipe 44 and through the feed pipe 31a to exit through the internal crown 31 ;
  • a cleaning fluid or inert for example compressed air, is fed through the auxiliary feed pipe 37 and through the feed pipe 30a to exit through the internal crown 30;
  • a comburent fluid is fed through the feed pipe 16a to exit through the first injection nozzle 16;
  • comburent or inert fluid is fed through the feed pipe 19a to exit through the second injection nozzle 19.
  • the command and control unit 33 keeps the (first) interception valves 39 and 45 in a closed operating condition, and the (second) interception valves 40 and 46 in an open operating condition, preventing the passage of the combustible and comburent fluids through the feed pipes 30a and 31a, and allowing the passage of a cleaning fluid, generally compressed air, or inert through the auxiliary feed pipes 37 and 44 and subsequently into the feed pipes 30a and 31a.
  • the choice of opening or closing one or the other of the two interception valves, in this operating mode depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
  • the command and control unit 33 keeps the interception valve 42 in an open operating condition, allowing the passage of the comburent fluid, generally oxygen, through the feed pipe 16a.
  • the command and control unit 33 keeps the interception valve 43 in a closed operating condition, preventing the passage of the cleaning fluid or inert, generally compressed air, through the auxiliary feed pipe 41.
  • a supersonic jet of oxygen develops through the first injection nozzle 16, having a Mach number comprised for example between about 2 and about 2.5, directed inside the bath of molten metal.
  • the supersonic jet of oxygen promotes all the oxidation reactions necessary for the melting process, at the same time generating a considerable energy contribution.
  • a third operating mode of the injection device 10 In a third operating mode of the injection device 10 according to the present invention it functions as an injector of a solid particulate.
  • This operating mode is applied particularly during the melting and refining of the metal being refined.
  • a cleaning fluid for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 44 and subsequently through the feed pipe 31a to exit through the external crown 31 ;
  • a cleaning fluid for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 37 and subsequently through the feed pipe 30a to exit through the internal crown 30;
  • a cleaning fluid for example compressed air, or an inert gas is fed through the auxiliary feed pipe 41 and subsequently through the feed pipe 16a to exit through the first injection nozzle 16;
  • the command and control unit 33 keeps the (first) interception valves 39, 42 and 45 in a closed operating condition, and the (second) interception valves 40, 43 and 46 in an open operating condition, preventing the passage of the combustible fluid through the feed pipe 30a and the comburent fluid, generally oxygen, through the feed pipes 16a and 31a, and allowing the passage of cleaning fluid, generally compressed air, or an inert gas first through the auxiliary feed pipes 37, 41 and 44 and subsequently through the feed pipes 16a, 30a and 31a.
  • the choice of opening or closing one or the other of the two interception valves, in this operating mode depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
  • a jet of solid material develops through the second injection nozzle 19.
  • This material is deposited inside the layer of slag above the liquid bath (a so-called "SOFT" injection) and can, depending on the type, cause reactions of reducing the iron oxides, oxidation reactions, modifications to the basicity and content of magnesite in the slag.
  • SOFT so-called "SOFT" injection
  • the solid particulate is conveyed to the injector through a pneumatic transport system using compressed air or, for some particular applications, an inert fluid.
  • the jet injected through the first injection nozzle 16 does not reach high speeds, and its only function is to keep the first injection nozzle 16 clean.
  • the injection device 10 In another operating mode of the injection device 10 according to the present invention it functions as a supersonic injector of oxygen and a "soft" injector of solid particulate.
  • This operating mode is applied particularly during the melting and refining.
  • a cleaning fluid or an inert gas is fed through the auxiliary feed pipe 44 and subsequently through the feed pipe 31 a to exit through the external crown 31 ;
  • a cleaning fluid or an inert gas is fed through the auxiliary feed pipe 37 and subsequently through the feed pipe 30a to exit through the internal crown 30;
  • a comburent fluid for example oxygen
  • a transport fluid, or an inert gas, and solid particulate are fed through the feed pipe 19a to exit through the second injection nozzle 19.
  • the command and control unit 33 keeps the (first) interception valves 39 and 45 in a closed operating condition, and the (second) interception valves 40 and 46 in an open operating condition, preventing the passage of the combustible and comburent fluid through the feed pipes 30a and 31a and allowing the passage of a cleaning fluid, generally compressed air, or an inert gas through the auxiliary feed pipes 37 and 44 and subsequently through the feed pipes 30a and 31a.
  • a cleaning fluid generally compressed air, or an inert gas
  • the choice of opening or closing one or the other of the two interception valves, in this operating mode depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
  • a comburent fluid is fed through the feed pipe 16a to exit through the first injection nozzle 16; and a comburent fluid or inert is fed through the feed pipe 19a to exit through the second injection nozzle 19.
  • the command and control unit 33 keeps the interception valve 42 in an open operating condition, allowing the passage of the comburent fluid, generally oxygen, through the feed pipe 16a.
  • the command and control unit 33 keeps the interception valve 43 in a closed operating condition, preventing the passage of the cleaning fluid or inert, generally compressed air, through the auxiliary feed pipe 41.
  • the injector develops a supersonic jet of oxygen through the first injection nozzle 16, having a Mach number comprised between about 2 and about 2.5, directed inside the bath of molten metal.
  • the supersonic jet of oxygen promotes all the oxidation reactions necessary for the melting process, at the same time generating a considerable energy contribution.
  • a transport fluid and solid particulate are fed through the feed pipe 19a, to exit through the second injection nozzle 19.
  • the injector injects the solid particulate through the second injection nozzle 19, which is deposited inside the layer of slag (a so-called "SOFT" injection) and can, depending on the type, cause reactions of reducing the iron oxides, modifications to the basicity and content of magnesite in the slag.
  • SOFT so-called "SOFT" injection
  • This operating mode is applied particularly during all the steps in which the process does not require any of the above operating modes.
  • a cleaning fluid for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 44 and subsequently through the feed pipe 31 a to exit through the external crown 31 ;
  • a cleaning fluid for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 37 and subsequently through the feed pipe 30a to exit through the internal crown 30;
  • a cleaning fluid for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 41 and subsequently through the feed pipe 16a to exit through the first injection nozzle 16;
  • a cleaning fluid for example compressed air, or an inert gas, is fed through the feed pipe 19a to exit through the second injection nozzle 19.
  • the injection device 10 operates in this mode during some steps, such as loading the furnace, tapping and in general all those times when no electric energy is supplied to the electrodes of the furnace.
  • steps such as loading the furnace, tapping and in general all those times when no electric energy is supplied to the electrodes of the furnace.
  • fluids are injected having the sole function of keeping the nozzles 16 and 19, and the burner unit 29, free from possible blockages, due to projections of slag and/or steel.
  • the command and control unit 33 keeps the interception valves 39, 42 and 45 in a closed operating condition, and the interception valves 40, 43 and 46 in an open operating condition, preventing the passage of the combustible fluid through the feed pipe 30a and the comburent fuel, generally oxygen, through the feed pipes 16a and 31a, and allowing the passage of a cleaning fluid, generally compressed air, or an inert gas, first through the auxiliary feed pipes 37, 41 and 44 and subsequently through the feed pipes 16a, 30a and 31a.
  • a cleaning fluid generally compressed air, or an inert gas
  • the choice of opening or closing one or the other of the two interception valves, in this operating mode depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
  • the jet injected through the first injection nozzle 16 does not reach high speeds, and its only function is to keep the injection nozzle 16 clean.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Massaging Devices (AREA)
  • Fuel-Injection Apparatus (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)

Abstract

Injection device to inject one or more fluids and/or solids into a metal bath, comprising a cooled main body (11), a fluids emission pipe (16a) suitable to inject at least a first fluid in the direction of the metal bath, and a fluids and/or solids emission pipe (19a) suitable to inject at least a second fluid and/or a solid, in the direction of the metal bath. The device comprises burner means (29), having respective fluids emission pipes (30a, 31a) disposed annularly around both the first injection means (16) and the second injection means (19), so as to define at least two crowns, respectively an internal crown (30) and an external crown (31) around them, said emission pipes (30a, 31a) being suitable to inject respectively at least a comburent fluid and at least a combustible fluid in the direction of the metal bath. The device comprises first valve means (42, 39, 45) able to selectively and respectively connect said fluids emission pipes (16a, 30a, 31a) with respective first feed means of a respective comburent fluid, for example oxygen, or combustible fluid, and second valve means (43, 40, 46) able to selectively and respectively connect, by means of auxiliary pipes (41, 37, 44), the fluids emission pipes (16a, 30a, 31a) with respective second feed means of a respective cleaning fluid, for example compressed air, or an inert gas.

Description

"INJECTION DEVICE AND RELATIVE OPERATIVE METHOD"
FIELD OF THE INVENTION
The present invention concerns an injection device usable in electric furnaces for producing steel, and able to inject at supersonic speed at least a stream of one or more fluids and/or solids used during the melting process and the subsequent refining of a metal charge. In particular, the injection device according to the present invention is used effectively in different operating modes, both to inject fluids and to inject solids and to give rise to a flame able to heat and melt the metal charge.
The present invention also concerns the method for the functioning of the injection device, in particular its different modes of use in the various operating steps.
BACKGROUND OF THE INVENTION
Injection devices used in electric arc furnaces are known, and in other applications in the steel and metallurgical industry, to inject gases and liquid and/or solid fuels, using lances or other types of devices, above and inside the melting metal bath.
Injection devices are also known suitable to inject the gases at supersonic speed, to obtain a high yield in the injection operations.
Burner devices are also known, which act on the scrap, in particular immediately after it has been unloaded into the furnace, in order to cause and/or accelerate the melting thereof.
Therefore, in the furnaces and more generally in traditional plants of the steel and metallurgical industry, it is known to provide different housing sites for the different types of injection devices, for example on the walls, on the roof of the furnace and/or in correspondence with the slagging door.
With regard to the production and maintenance of the different injection devices provided in known plants, these involve high costs and long times, particularly due to the specific nature of the assembly, management and maintenance operations.
From the operating point of view, injection devices are mounted on the walls of the furnace putting the end, or emitter nozzle, far from the metal bath, so as to preserve their integrity with respect to the deteriorating agents, such as the extremely high temperature, the splashes of molten metal and/or slag, corrosion, and impacts with the solid charge.
This safety and operating constraint contrasts with the technological features connected to the fluid-dynamic yield of the jet delivered, inasmuch as it makes it necessary to considerably increase the exit speed of the stream so as to keep penetration high through the layer of slag and inside the liquid metal bath.
Furthermore, the greater the distance of the introduction point of the injection device from the zone of impact in the metal bath, the more the risks of weakening and dispersion of the jet increase, and hence the risks of loss of performance and speed in correspondence with the zone of impact.
Solutions are also known in which both the burner and the injectors of gas and/or solids are combined with each other in a single injection device, equipped (or not) with pre-mixing chambers in order to stabilize the flame. These combined devices provide that the flame generated by the burner develops around the injectors of gas and/or solids. An example of such devices is described in US-B 1-6.372.010.
Due to their conformation, such known devices have a rigid and dedicated functioning of their parts, that is, the burner exclusively provides functioning with generation of the flame, and therefore such devices can have only the simultaneous functioning of the burner and the injectors.
This functioning condition necessarily entails the use of a flame also during the supersonic injection of a fluid and/or solid, causing an increase in the consumption of comburent and combustible gas during the process.
One purpose of the present invention is to achieve an injection device, without a pre-mixing chamber, which is easy and economical to make, which allows to reduce the times and costs of installation, management and maintenance, and which can be brought near to the zone of impact in the metal bath, reducing to a minimum the risk that parts of the injection device are subjected to splashes of molten metal and/or slag, corrosion and impacts due to the metal charge.
Another purpose of the present invention is to perfect a method which allows to reduce the times and costs of installation, management and maintenance, and which allows to bring the injection device near the zone of impact in the metal bath, reducing to a minimum the risk that parts of the injection device are subjected to splashes of molten metal and/or slag, corrosion and impacts due to the metal charge.
The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.
SUMMARY OF THE INVENTION
The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.
In accordance with the above purposes, an injection device according to the present invention is applied to inject one or more fluids and/or solids inside a furnace for melting a metal charge and comprises a cooled main body provided with a plurality of feed pipes, to feed fluids and/or solids into it.
The injection device also comprises first injection means mounted on the main body and suitable to inject at supersonic speed a stream of a first fluid, for example air or oxygen, in the direction of the metal bath.
Furthermore, the injection device comprises second injection means, also mounted on the main body in a position adjacent and separate with respect to the first injection means, and suitable to inject a second fluid and/ or a solid, the latter for example in the form of particulate, in the direction of the metal bath.
The injection device also comprises burner means, also mounted on the main body and having one or more emission pipes disposed externally and around both the first injection means and the second injection means, so as to define, substantially, one or more crowns around them. Each emission pipe is fed by a first feed pipe to feed a combustible, comburent or inert fluid, and by a second pipe to feed a comburent or inert fluid.
According to a characteristic feature of the present invention, the injection device comprises first valve means able to intercept one and/or the other of the combustible and comburent fluids in order to selectively interrupt the feed to the emission pipes at least of the first injection means and the burner means, and second valve means, drivable alternatively to said first valve means, to feed cleaning and/or protection fluids through at least said first injection means and said burner means, so as to keep the pipes clean of detritus and/or slag.
With the present invention it is possible to selectively exclude the feed of the combustible and comburent fluid to the emission pipes of the first injection means and burner means, so as to prevent the formation of the flame, but in any case maintaining the delivery of a fluid, for example compressed air, inert gas or other suitable fluid, for the sole purpose of guaranteeing emission pipes that are free of slag or steel residues.
In particular, the switching of the fluid delivered is achieved by closing the first valve means disposed along a relative feed line, the so-called main feed line, and by opening second valve means in order to render a second feed line operative, the so-called auxiliary feed line, so as to keep the respective lines independent of each other and to allow a correct management of the respective emissions.
In this way, depending on the different operating steps provided in the production of the steel, the burner means can selectively emit either a flame or a jet of comburent gas, or a jet of compressed air, or a jet of inert gas, in any case so as to form a protective screen to convey the streams of fluids and/or solids injected into the liquid bath, preserving and protecting the first and second injection means from possible occlusions and preventing dispersions of the fluids and/or solids injected into the atmosphere of the furnace.
Furthermore, with the configuration of the injection device according to the present invention, there is a limited exchange of quantity of motion between the stream injected by the first injection means at supersonic speed and the stream injected by the second injection means.
In this way, it is possible to avoid accelerating excessively the stream injected by the second injection means and to take it, passing through the layer of slag, directly inside the metal bath. The stream injected at supersonic speed by the first injection means in fact contributes to conveying the stream injected by the second injection means inside the layer of slag separated from the bath, preventing it from being dispersed into the atmosphere of the furnace.
The reciprocally adjacent position of the first injection means and the second injection means allows to exploit the fluid injected by the first injection means so as to keep the second injection means free from possible occlusions caused by splashes of slag and/or liquid metal, and to prevent, as happens in current equipment, the need to use another jet of oxygen or a flame, to achieve the same purpose.
According to a variant, both the first injection means and the second injection means comprise an injection terminal conformed specifically for the operating conditions and the fluids and/or solids to be injected.
According to another variant, the injection terminal of the first injection means comprises at least a segment having a section useful for the passage of the fluid, which section has limited dimensions with respect to the remaining part, so as to allow to modify, also at different points, the fluid-dynamic conditions of the passage of the fluid through the terminal, and to determine the injection at supersonic speed.
According to another variant, the first injection means comprise at least a first nozzle, while the second injection means comprise a second nozzle.
In this variant solution, the longitudinal axes of the two nozzles are parallel to each other and lie on the same plane.
According to a variant, the lying plane common to the two longitudinal axes of the nozzles is substantially vertical.
According to a variant, the lying plane common to the two longitudinal axes of the nozzles is substantially horizontal.
According to a variant, the lying plane common to the two longitudinal axes of the nozzles is inclined with respect to ideal horizontal and vertical references.
According to another variant, the burner means comprise two distinct types of emission pipes, a first defining an internal crown, and a second defining an external crown.
According to another variant, the emission pipes that define the internal crown are substantially parallel to each other and to a longitudinal axis of the injection device.
According to another variant, the emission pipes that define the external crown are inclined on two axes with respect to a median longitudinal axis of the injection device, to deliver the relative jet of fluid with a tangential component that facilitates the mixing of the fluids between the two emission pipes.
BRIEF DESCRIPTION OF THE DRAWINGS These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein:
- fig. 1 is a schematic lateral view of an injection device according to the present invention;
- fig. 2 is a schematized front view of the injection device in fig. 1;
- fig. 3 is a section from III to III of fig. 2;
- fig. 4 is a section from IV to IV of fig. 2;
- fig. 5 is a variant of fig. 4;
- fig. 6 is a section from V to V of fig. 2;
- fig. 7 is a diagram of a feed unit of the injection device in fig. 1.
To facilitate comprehension, the same reference numbers have been used, where possible, to identify common elements in the drawings that are substantially identical. It is understood that elements and characteristics of one form of embodiment can conveniently be incorporated into other forms of embodiment without further clarifications.
DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF
EMBODIMENT
With reference to the attached drawings, the reference number 10 denotes in its entirety an injection device according to the present invention. The injection device 10 is advantageously but not exclusively applied in the steps of injecting comburent and/or refining fluids, during the melting of a metal alloy, in which scrap metal and other materials, for example carbon, that make up the alloy, are made to melt in an electric furnace inside a liquid bath.
The injection device 10 comprises, generally, a main body 1 1 substantially cylindrical in shape and without a pre-mixing chamber, a first injection nozzle
16, a second injection nozzle 19 and a burner unit 29.
The injection device 10 also comprises a feed unit 32, disposed upstream of the main body 1 1 and able to feed the injection nozzles 16 and 19 with fluids and/or solids, and the burner unit 29, depending on programmed or programmable operating conditions.
In particular, the main body 1 1 comprises a plurality of connection pipes, of which the specific functions will be described in more detail hereafter, which branch off from the external surface of the main body 1 1 so as to connect the main body 1 1 to the feed unit 32, in order to feed the fluids and/or solids used by the injection device during the process.
The main body 1 1 is also equipped with pipes able to guarantee the passage of a cooling fluid, both in an external cooling chamber 46 and also in internal cooling chambers 47.
The first injection nozzle 16 is suitable for the passage of a fluid and is made inside the main body 1 1 , in a condition substantially parallel to a longitudinal axis of the main body 1 1.
In particular, the first injection nozzle 16 comprises a rear end fluidically connected to a relative feed pipe 16a through which the feed unit 32 feeds a relative fluid, for example a gas, and a front end constrained to an injection terminal 17.
Internally the injection terminal 17 has a segment with a reduced section, to vary the fluid-dynamic conditions of passage of the fluid and to determine the supersonic speed injection. The internal section of the injection terminal 17 is for example of the type known as "De-Laval nozzle", to accelerate a fluid from a subsonic speed to a supersonic speed.
The second injection nozzle 19 is functionally suitable to allow the passage inside it of both gassy substances and of solid particulate, and is substantially parallel to the longitudinal axis of the main body 1 1.
This positioning takes the second injection nozzle 19 to a position substantially parallel and adjacent to the first injection nozzle 16, so that the respective longitudinal axes of the two nozzles 16 and 19 lie on the same plane. In this case, the plane on which the longitudinal axes of the two nozzles 16 and 19 lie is substantially vertical and also comprises the median longitudinal axis of the main body 11.
It cannot be excluded that, in other forms of embodiment, the plane is disposed substantially horizontal, or inclined with respect to the traditional horizontal and vertical references.
According to other variants, the two nozzles 16 and 19 are disposed substantially parallel to each other, but in non-symmetrical conditions with respect to the median longitudinal axis of the main body 1 1. The second injection nozzle 19 also comprises an injection terminal 20 through which the fluid and/or solid to be injected into the liquid bath is delivered.
The second injection nozzle 19 also comprises, integrated therewith, in the rear part, a feed pipe 19a, through which the feed unit 32 feeds the gas and/or the solid particulate provided for injection.
The burner unit, denoted in its entirety by the reference number 29, comprises two series of emission pipes 22 and 23, open toward the front surface of the main body 1 1, that is, the surface through which the two injection nozzles 16 and 19 open toward the outside.
The series of nozzles 22 and 23 of the burner unit 29 define two distinct crowns, respectively internal 30 and external 31, both external and surrounding the injection nozzles 16 and 19.
The internal crown 30, consisting of a series of nozzles 22 disposed circularly around the two injection nozzles 16 and 19 and substantially parallel to each other, is connected to a feed pipe 30a. The feed pipe 30a is open on one side toward the respective nozzles 22 and, through these, toward the front surface; on the other side it is connected to the feed unit 32.
Through the pipe 30a the feed unit 32 can feed the nozzles 22, and hence the internal crown 30, with a combustible fluid, or with a cleaning fluid, such as compressed air, or with an inert gas.
The external crown 3 1 , consisting of a series of nozzles 23 disposed circularly around the two injection nozzles 16 and 19 and inclined on two axes with respect to a plane passing through the median longitudinal axis of the main body 1 1, is connected to a main feed pipe 31a. The nozzles 23 are oriented in such a manner as to impart to the jet delivered a tangential component, called "SWIRL", thus promoting the rapid mixing of the reagents and the stability of the flame, even in the absence of a pre-mixing chamber. The feed pipe 31a is open on one side, toward the respective nozzles 23 and, through the latter, toward the front surface, and on the other side is connected to the feed unit 32.
The feed unit 32 can feed, through the pipe 3 1a, the nozzles 23 and hence the crown 31, with a comburent fluid or with a cleaning fluid or with inert gas.
With particular reference to fig. 2 and the sections of figs. 4 and 5, each nozzle 23 has a first angle of inclination a with respect to a plane passing through the longitudinal axis of the main body 1 1 and the axis of the corresponding nozzle 22, and a second angle of inclination β again with respect to the axis of the corresponding nozzle 22.
The first angle of inclination a has values preferably comprised between about 0° and about 90°, while the second angle of inclination β has values preferably comprised between about 0° and about 80°.
In the variant solution shown in fig. 5, the two nozzles 22 and 23 do not directly protrude from the front surface of the main body 1 1 of the injection device 10, but face each other in a common chamber 27.
The depth of the chamber 27 may be made as desired, depending on specific operating requirements.
Moreover, each nozzle 23 of the external crown 31 preferably has its longitudinal axis lying on the plane passing through the axis of the corresponding nozzle 22 of the internal crown and inclined by the first angle of inclination a with respect to the plane passing through the longitudinal axis of the main body 1 1 and the longitudinal axis of the nozzle 22.
In the case shown in fig. 2, solely to illustrate an alternative solution to the indicated preferred solution, each nozzle 23 has its longitudinal axis offset by an amount X with respect to the plane passing through the axis of the corresponding nozzle 22.
Since the two crowns 30 and 31 are disposed circularly around the injection nozzles 16 and 19, it is possible to create a screen formed by the fluids exiting from the two crowns 30 and 31 to convey the fluids and particulate injected through the two nozzles 16 and 19 toward the layer of slag, and prevent dispersions thereof into the atmosphere of the furnace 1 1.
The feed unit 32, shown schematically in fig. 7, comprises a command and control unit 33, a unit to manage and feed the fluids 35, and a unit to manage and feed the solids 36.
The command and control unit 33 is of a substantially known type, such as for example a PLC processor (Programmable Logic Control), a CNC processor (Computer Numerical Control) or other, and is connected electronically both to the management and feed unit 35 and also to the management and feed unit 36, so as to command the various deliveries and feeds through the relative main feed pipes 16a, 19a, 30a and 31a.
The management and feed unit 35 provides, associated therewith, the feed pipes 16a, 30a and 31a.
In particular, the management and feed unit 35 also comprises the auxiliary feed pipes 37, 41 and 44, the first interception valves 39, 42 and 45, disposed along the main emission lines, and the second interception valves 40, 43 and 46 disposed along the auxiliary emission lines.
The auxiliary feed pipe 37 is fluidically connected to the feed pipe 30a, upstream of the inlet to the crown 30, but downstream of the interception valve 39, with respect to the direction in which the fluid flows.
A cleaning fluid, for example compressed air, or an inert gas, may selectively be made to flow through the auxiliary feed pipe 37.
The first interception valve 39 is fluidically connected to the feed pipe 30a, upstream of the connection zone between the feed pipe 30a and the auxiliary feed pipe 37.
The first interception valve 39 selectively conditions the passage of the fluid fed by the feed pipe 30a.
The second interception valve 40 is fluidically associated with the auxiliary feed pipe 37, upstream of the connection zone between the auxiliary feed pipe 37 and the feed pipe 30a.
The second interception valve 40 selectively conditions the passage of the fluid fed by the auxiliary feed pipe 37.
Both the first interception valve 39 and the second interception valve 40 are electronically commanded by the command and control unit 33, so as to allow the passage of the fluid through the relative feed pipe, main 30a or auxiliary 37, alternately.
In this way, through the internal crown 30 it is possible to deliver alternately a combustible fluid, such as methane, and hence facilitate the formation of the flame with the comburent liquid exiting from the external crown 31, or a cleaning fluid, such as compressed air, or an inert gas which, mixed with the cleaning fluid or inert gas exiting from the external crown 31, determines a fluidic protection barrier for the injection nozzles 16 and 19. The auxiliary feed pipe 44 is fluidically connected to the feed pipe 31a, upstream of the inlet to the crown 31 , with respect to the direction in which the fluid flows.
A cleaning fluid, such as compressed air, or an inert gas, is made to flow through the auxiliary feed pipe 44.
The first interception valve 45 is fluidically associated with the feed pipe 31a, upstream of the connection zone between the feed pipe 31a and the auxiliary feed pipe 44.
The first interception valve 45 selectively conditions the passage of the fluid fed by the feed pipe 31 a.
The second interception valve 46 is fluidically associated with the auxiliary feed pipe 44 upstream of the connection zone between the auxiliary feed pipe 44 and the feed pipe 31 a.
The second interception valve 46 selectively conditions the passage of the fluid fed by the auxiliary feed pipe 44.
Both the first interception valve 45 and the second interception valve 46 are electronically commanded by the command and control unit, so as to allow the passage of the fluid through the relative feed pipe, main 31a or auxiliary 44, alternately.
In this way, through the external crown 31 it is possible to deliver alternately a comburent fluid, for example pure oxygen, and hence facilitate the formation of the flame with the combustible fluid exiting from the internal crown 30, or a cleaning fluid, such as compressed air or an inert gas which, mixed with the cleaning fluid or inert gas exiting from the internal crown 30, determines a fluidic protection barrier for the injection nozzles 16 and 19.
Finally, the auxiliary feed pipe 41 is fluidically connected to the feed pipe 16a, upstream of the inlet to the injection nozzle 16, with respect to the direction in which the fluid flows.
A cleaning fluid, such as compressed air, or an inert gas is made to flow through the auxiliary feed pipe 41.
The first interception valve 42 is fluidically associated with the feed pipe 16a, upstream of the connection zone between the feed pipe 16a and the auxiliary feed pipe 41. The first interception valve 42 selectively conditions the passage of the fluid fed by the feed pipe 16a.
The second interception valve 43 is fluidically associated with the auxiliary feed pipe 41 upstream of the connection zone between the auxiliary feed pipe 41 and the feed pipe 16a.
The second interception valve 43 selectively conditions the passage of the fluid fed by the auxiliary feed pipe 41.
Both the first interception valve 42 and the second interception valve 43 are electronically commanded by the command and control unit 33, so as to allow the passage of the fluid through the relative feed pipe, main 16a or auxiliary 41, alternately.
In this way, through the injection nozzle 16 it is possible to deliver alternately a comburent fluid, and hence facilitate the refining of a metal alloy during the melting steps inside an electric furnace, or a cleaning fluid, such as compressed air, or an inert gas, with the sole purpose of keeping the injection nozzle 16 free from possible occlusions caused by splashes of slag and/or liquid metal.
The management and feed unit 36 provides, associated therewith, the feed pipe 19a, fluidicially connected with the nozzle 19 to allow the passage inside it of both gassy substances and solid particulate.
The main body 1 1 is equipped with two chambers, inside which a cooling fluid is made to circulate, preferentially water, with the purpose of guaranteeing the integrity of the device when exposed to the extremely high temperatures registered inside the electric furnace for melting metals. The first chamber 46, or external chamber, is fluidically connected with an inlet pipe 46a of the cooling fluid and with an exit pipe 46b, through which the fluid exits. The second chamber 47, or internal chamber, is fluidically connected with an inlet pipe 47a of the cooling fluid and with an exit pipe 47b, through which the fluid exits.
Some of the possible functioning modes of the injection device 10 will now be described.
In a first operating mode of the injection device 10, it functions as a burner, to heat the iron scrap before the latter sinks completely into the liquid bath inside the furnace.
In this first mode the fluids are fed by the feed unit 32 according to the following feed mode:
- a comburent fluid is fed through the feed pipe 31a to exit through the external crown 31 ;
- a combustible fluid is fed through the feed pipe 30a to exit through the internal crown 30;
- a cleaning fluid, for example compressed air, or an inert gas is fed through the feed pipe 16a to exit through the first injection nozzle 16; and
- a cleaning fluid, for example compressed air, or an inert gas is fed through the feed pipe 19a to exit through the second injection nozzle 19.
In this mode, the command and control unit 33 keeps the (first) interception valves 39 and 45 in an open operating condition, allowing the respective combustible and comburent fluids to pass through the feed pipes 30a and 31a. At the same time, the command and control unit 33 keeps the (second) interception valves 40 and 46 in a closed operating condition, preventing the passage of cleaning fluid or inert, generally compressed air, through the auxiliary feed pipes 37 and 44. Furthermore, the command and control unit keeps the interception valve 42 in a closed operating condition, preventing the passage of the comburent fluid, generally oxyen, through the feed pipe 16a. At the same time, the command and control unit 33 keeps the interception valve 43 in an open operating condition, allowing a cleaning fluid, generally compressed air, to pass through the auxiliary feed pipe 41.
In this way a flame develops through the two crowns 30 and 31 which, thanks to the extremely high speed and temperature reached by the combustion gases, causes the rapid melting of the metal charge.
In this mode, the stream of cleaning fluid or inert injected by the first injection nozzle 16 does not reach high speeds, and its only function is to keep the injection nozzle 16 clean.
In a second operating mode of the injection device 10 according to the present invention it functions as a supersonic injector of a comburent fluid.
This operating mode is applied particularly during the melting and refining steps of the metal in formation.
The fluids injected during this mode are:
- a cleaning fluid or inert, for example compressed air, is fed through the auxiliary feed pipe 44 and through the feed pipe 31a to exit through the internal crown 31 ;
- a cleaning fluid or inert, for example compressed air, is fed through the auxiliary feed pipe 37 and through the feed pipe 30a to exit through the internal crown 30;
- a comburent fluid is fed through the feed pipe 16a to exit through the first injection nozzle 16; and
- a comburent or inert fluid is fed through the feed pipe 19a to exit through the second injection nozzle 19.
During this mode, the command and control unit 33 keeps the (first) interception valves 39 and 45 in a closed operating condition, and the (second) interception valves 40 and 46 in an open operating condition, preventing the passage of the combustible and comburent fluids through the feed pipes 30a and 31a, and allowing the passage of a cleaning fluid, generally compressed air, or inert through the auxiliary feed pipes 37 and 44 and subsequently into the feed pipes 30a and 31a. For each pair of valves, 39-40 or 45-46, the choice of opening or closing one or the other of the two interception valves, in this operating mode, depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
Furthermore, the command and control unit 33 keeps the interception valve 42 in an open operating condition, allowing the passage of the comburent fluid, generally oxygen, through the feed pipe 16a. At the same time, the command and control unit 33 keeps the interception valve 43 in a closed operating condition, preventing the passage of the cleaning fluid or inert, generally compressed air, through the auxiliary feed pipe 41.
A supersonic jet of oxygen develops through the first injection nozzle 16, having a Mach number comprised for example between about 2 and about 2.5, directed inside the bath of molten metal. The supersonic jet of oxygen promotes all the oxidation reactions necessary for the melting process, at the same time generating a considerable energy contribution.
In a third operating mode of the injection device 10 according to the present invention it functions as an injector of a solid particulate.
This operating mode is applied particularly during the melting and refining of the metal being refined.
The fluids injected in this mode are:
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 44 and subsequently through the feed pipe 31a to exit through the external crown 31 ;
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 37 and subsequently through the feed pipe 30a to exit through the internal crown 30;
- a cleaning fluid, for example compressed air, or an inert gas is fed through the auxiliary feed pipe 41 and subsequently through the feed pipe 16a to exit through the first injection nozzle 16; and
- a transport fluid and solid particulate are fed through the feed pipe 19a to exit through the second injection nozzle 19.
During this step, the command and control unit 33 keeps the (first) interception valves 39, 42 and 45 in a closed operating condition, and the (second) interception valves 40, 43 and 46 in an open operating condition, preventing the passage of the combustible fluid through the feed pipe 30a and the comburent fluid, generally oxygen, through the feed pipes 16a and 31a, and allowing the passage of cleaning fluid, generally compressed air, or an inert gas first through the auxiliary feed pipes 37, 41 and 44 and subsequently through the feed pipes 16a, 30a and 31a.
For each pair of valves, 39-40 or 45-46 or 42-43, the choice of opening or closing one or the other of the two interception valves, in this operating mode, depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
A jet of solid material develops through the second injection nozzle 19. This material is deposited inside the layer of slag above the liquid bath (a so-called "SOFT" injection) and can, depending on the type, cause reactions of reducing the iron oxides, oxidation reactions, modifications to the basicity and content of magnesite in the slag. The solid particulate is conveyed to the injector through a pneumatic transport system using compressed air or, for some particular applications, an inert fluid.
Compared with the previous operating mode of supersonic injection of oxygen, the jet injected through the first injection nozzle 16 does not reach high speeds, and its only function is to keep the first injection nozzle 16 clean.
In another operating mode of the injection device 10 according to the present invention it functions as a supersonic injector of oxygen and a "soft" injector of solid particulate.
This operating mode is applied particularly during the melting and refining.
The fluids injected in this mode are:
- a cleaning fluid or an inert gas is fed through the auxiliary feed pipe 44 and subsequently through the feed pipe 31 a to exit through the external crown 31 ; - a cleaning fluid or an inert gas is fed through the auxiliary feed pipe 37 and subsequently through the feed pipe 30a to exit through the internal crown 30;
- a comburent fluid, for example oxygen, is fed through the feed pipe 16a to exit through the first injection nozzle 16; and
- a transport fluid, or an inert gas, and solid particulate are fed through the feed pipe 19a to exit through the second injection nozzle 19.
During this step too, the command and control unit 33 keeps the (first) interception valves 39 and 45 in a closed operating condition, and the (second) interception valves 40 and 46 in an open operating condition, preventing the passage of the combustible and comburent fluid through the feed pipes 30a and 31a and allowing the passage of a cleaning fluid, generally compressed air, or an inert gas through the auxiliary feed pipes 37 and 44 and subsequently through the feed pipes 30a and 31a. For each pair of valves, 39-40 or 45-46, the choice of opening or closing one or the other of the two interception valves, in this operating mode, depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
A comburent fluid is fed through the feed pipe 16a to exit through the first injection nozzle 16; and a comburent fluid or inert is fed through the feed pipe 19a to exit through the second injection nozzle 19.
Furthermore, the command and control unit 33 keeps the interception valve 42 in an open operating condition, allowing the passage of the comburent fluid, generally oxygen, through the feed pipe 16a. At the same time, the command and control unit 33 keeps the interception valve 43 in a closed operating condition, preventing the passage of the cleaning fluid or inert, generally compressed air, through the auxiliary feed pipe 41.
The injector develops a supersonic jet of oxygen through the first injection nozzle 16, having a Mach number comprised between about 2 and about 2.5, directed inside the bath of molten metal.
The supersonic jet of oxygen promotes all the oxidation reactions necessary for the melting process, at the same time generating a considerable energy contribution.
A transport fluid and solid particulate are fed through the feed pipe 19a, to exit through the second injection nozzle 19.
At the same time as the supersonic injection of oxygen, the injector injects the solid particulate through the second injection nozzle 19, which is deposited inside the layer of slag (a so-called "SOFT" injection) and can, depending on the type, cause reactions of reducing the iron oxides, modifications to the basicity and content of magnesite in the slag.
In another operating mode of the injection device 10 it functions in stand-by .
This operating mode is applied particularly during all the steps in which the process does not require any of the above operating modes.
The fluids injected in this mode are:
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 44 and subsequently through the feed pipe 31 a to exit through the external crown 31 ;
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 37 and subsequently through the feed pipe 30a to exit through the internal crown 30;
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe 41 and subsequently through the feed pipe 16a to exit through the first injection nozzle 16; and
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the feed pipe 19a to exit through the second injection nozzle 19.
The injection device 10 operates in this mode during some steps, such as loading the furnace, tapping and in general all those times when no electric energy is supplied to the electrodes of the furnace. In practice, in these steps, through the nozzles 16 and 19, and the burner unit 29, fluids are injected having the sole function of keeping the nozzles 16 and 19, and the burner unit 29, free from possible blockages, due to projections of slag and/or steel.
During this step, the command and control unit 33 keeps the interception valves 39, 42 and 45 in a closed operating condition, and the interception valves 40, 43 and 46 in an open operating condition, preventing the passage of the combustible fluid through the feed pipe 30a and the comburent fuel, generally oxygen, through the feed pipes 16a and 31a, and allowing the passage of a cleaning fluid, generally compressed air, or an inert gas, first through the auxiliary feed pipes 37, 41 and 44 and subsequently through the feed pipes 16a, 30a and 31a.
For each pair of valves, 39-40 or 45-46 or 42-43, the choice of opening or closing one or the other of the two interception valves, in this operating mode, depends on determinate or determinable operating conditions, programmed or programmable, in the command and control unit 33.
In this stand-by mode, the jet injected through the first injection nozzle 16 does not reach high speeds, and its only function is to keep the injection nozzle 16 clean.
It is clear that modifications and/or additions of parts may be made to the injection device 10 as described heretofore, without departing from the field and scope of the present invention.
It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of injection device, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.

Claims

1. Injection device to inject one or more fluids and/oir solids into a metal bath, comprising:
- a cooled main body (1 1);
- first injection means (16) mounted on said main body (1 1) and comprising at least a fluids emission pipe (16a) suitable to inject at supersonic speed at least a first fluid in the direction of the metal bath;
- second injection means (19) mounted on said main body (1 1) in a position adjacent and separate with respect to the first injection means (16), comprising at least a fluids and/or solids emission pipe (19a) suitable to inject at least a second fluid and/or a solid, in the direction of the metal bath,
- burner means (29), also mounted on the main body (1 1) and having respective fluids emission pipes (30a, 31a) disposed annularly around both the first injection means (16) and also the second injection means (19), so as to define at least two crowns, respectively an internal crown (30) and an external crown (31) around them, said emission pipes (30a, 31a) being suitable to inject respectively at least a comburent fluid and at least a combustible fluid in the direction of the metal bath, characterized in that it also comprises:
- first valve means (42, 39, 45) able to selectively and respectively connect said fluids emission pipes (16a, 30a, 31a) with respective first feed means of a respective comburent fluid, for example oxygen, or combustible fluid;
- second valve means (43, 40, 46) able to selectively and respectively connect, by means of auxiliary pipes (41, 37, 44), said fluids emission pipes (16a, 30a, 31a) with respective second feed means of a respective cleaning fluid, for example compressed air, or an inert gas;
wherein, when said first valve means (42, 39, 45) are open, said second valve means (43, 40, 46) are closed, and vice versa.
2. Device as in claim 1, characterized in that the internal crown (30) of the burner means (29) is defined by first emission pipes (22) oriented substantially parallel to each other and to a longitudinal axis of the main body (1 1).
3. Device as in claim 1 or 2, characterized in that the external crown (31) of the burner means (29) is defined by second emission pipes (23) that are inclined on two axes with respect to a longitudinal axis of the main body (1 1), in order to deliver the relative jet of fluid with a tangential component.
4. Device as in any claim hereinbefore, characterized in that it comprises a feed unit (32) to which both the first injection means (16), the second injection means (19) and also the burner means (29) are connected, and which is provided with a command and control unit (33), a unit to manage and feed the fluids (35) which feeds the pipes (16a, 30a, 31a), and a unit to manage and feed the solids (36) which feeds the emission pipe (19a) of the fluids and/or solids.
5. Device as in claim 4, characterized in that the command and control unit (33) is electronically connected both to the unit to manage and feed the fluids (35), the unit to manage and feed the solids (36), and also to the first and second valve means (39, 40, 42, 43, 45, 46), so as to command the various deliveries and feeds through the relative feed pipes (16a, 19a, 30a, 31a).
6. Device as in any claim hereinbefore, characterized in that both the first injection means (16) and the second injection means (19) comprise a respective injection terminal (17, 20), wherein at least the injection terminal (17) of the first injection means (16) comprises at least a segment having a section usable for the passage of the fluid, the section having reduced sizes with respect to the remaining part, so as to change the fluid-dynamic conditions of passage of the fluid and to determine the supersonic speed injection.
7. Device as in any claim hereinbefore, wherein the first injection means comprise at least a first nozzle (16), while the second injection means comprise a second nozzle (19), characterized in that the longitudinal axes of the two nozzles (16, 19) are parallel to each other and lie on a same plane.
8. Device as in claim 7, characterized in that the lying plane common to the two longitudinal axes of the nozzles (16, 19) is substantially vertical.
9. Device as in claim 7, characterized in that the lying plane common to the two longitudinal axes of the nozzles (16, 19) is substantially horizontal.
10. Device as in claim 7, characterized in that the lying plane common to the two longitudinal axes of the nozzles (16, 19) is inclined with respect to ideal horizontal and vertical references.
1 1. Method to inject one or more fluids and/or solids into a metal bath, by means of an injection device as in any claim hereinbefore, characterized in that it provides at least a first operating mode, functioning as burner, wherein the fluids are fed according to the following feed mode:
- a comburent fluid is fed through the feed pipe (31a) to exit through the external crown (31);
- a combustible fluid is fed through the feed pipe (30a) to exit through the internal crown (30);
- a cleaning fluid or an inert is fed through the feed pipe (16a) to exit through the first injection nozzle (16); and
- a cleaning fluid or an inert is fed through the feed pipe (19a) to exit through the second injection nozzle (19).
12. Method as in claim 1 1, characterized in that it provides a second operating mode, functioning as a supersonic injector of a comburent fluid, wherein the fluids are fed according to the following feed mode:
- a cleaning fluid or inert gas is fed through the auxiliary feed pipe (44) and through the feed pipe (31a) to exit through the internal crown (30);
- a cleaning fluid or inert is fed through the auxiliary feed pipe (37) and through the feed pipe (30a) to exit through the internal crown (30);
- a comburent fluid is fed through the feed pipe (16a) to exit through the first injection nozzle (16); and
- a cleaning fluid or inert is fed through the feed pipe (19a) to exit through the second injection nozzle (19).
13. Method as in claim 1 1, characterized in that it provides a third operating mode, functioning as an injector of solid particulate, wherein the fluids are fed according to the following feed mode:
- a cleaning fluid, or an inert gas, is fed through the auxiliary feed pipe (44) and subsequently through the feed pipe (31a) to exit through the external crown (31);
- a cleaning fluid, or an inert gas, is fed through the auxiliary feed pipe (37) and subsequently through the feed pipe (30a) to exit through the internal crown (30);
- a cleaning fluid, or an inert gas, is fed through the auxiliary feed pipe (41) and subsequently through the feed pipe (16a) to exit through the first injection nozzle (16); and
- a transport fluid, or an inert gas, and solid particulate are fed through the feed pipe (19a) to exit through the second injection nozzle (19).
14. Method as in claim 1 1, characterized in that it provides a fourth operating mode, functioning as a supersonic injector of oxygen and "soft" injector of solid particulate, wherein the fluids are fed according to the following feed mode:
- a cleaning fluid or an inert gas is fed through the auxiliary feed pipe (44) and subsequently through the feed pipe (31a) to exit through the external crown (31); - a cleaning fluid or an inert gas is fed through the auxiliary feed pipe (37) and subsequently through the feed pipe (30a) to exit through the internal crown (30);
- a comburent fluid is fed through the feed pipe (16a) to exit through the first injection nozzle (16); and
- a transport fluid, or an inert gas, and solid particulate are fed through the feed pipe (19a) to exit through the second injection nozzle (19).
15. Method as in claim 1 1, characterized in that it provides a fifth operating mode, functioning in stand-by, wherein the fluids are fed according to the following feed mode:
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe (44) and subsequently through the feed pipe (31a) to exit through the external crown (31);
- a cleaning fluid, for example compressed air, or an inert gas, is fed through the auxiliary feed pipe (37) and subsequently through the feed pipe (30a) to exit through the internal crown (30);
- a cleaning fluid, or an inert gas, is fed through the auxiliary feed pipe (41) and subsequently through the feed pipe (16a) to exit through the first injection nozzle (16); and
- a cleaning fluid, or an inert gas, is fed through the feed pipe (19a) to exit through the second injection nozzle (19).
PCT/IB2010/003218 2009-12-14 2010-12-14 Injection device and relative operative method WO2011073760A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITUD2009A000227 2009-12-14
ITUD2009A000227A IT1397597B1 (en) 2009-12-14 2009-12-14 INJECTOR DEVICE AND ITS OPERATING PROCEDURE.

Publications (1)

Publication Number Publication Date
WO2011073760A1 true WO2011073760A1 (en) 2011-06-23

Family

ID=42077044

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2010/003218 WO2011073760A1 (en) 2009-12-14 2010-12-14 Injection device and relative operative method

Country Status (2)

Country Link
IT (1) IT1397597B1 (en)
WO (1) WO2011073760A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020173088A1 (en) * 2019-02-27 2020-09-03 中冶赛迪工程技术股份有限公司 Coaxial dual supersonic speed oxygen flow coherent oxygen lance

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6372010B1 (en) 1999-12-10 2002-04-16 Process Technology International, Inc. Method for metal melting, refining and processing
WO2004007776A2 (en) * 2002-07-11 2004-01-22 Danieli & C. Officine Meccaniche S.P.A. Injector-burner for metal melting furnaces

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6372010B1 (en) 1999-12-10 2002-04-16 Process Technology International, Inc. Method for metal melting, refining and processing
WO2004007776A2 (en) * 2002-07-11 2004-01-22 Danieli & C. Officine Meccaniche S.P.A. Injector-burner for metal melting furnaces

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020173088A1 (en) * 2019-02-27 2020-09-03 中冶赛迪工程技术股份有限公司 Coaxial dual supersonic speed oxygen flow coherent oxygen lance

Also Published As

Publication number Publication date
ITUD20090227A1 (en) 2011-06-15
IT1397597B1 (en) 2013-01-16

Similar Documents

Publication Publication Date Title
US6322610B1 (en) Integrated device to inject oxygen, technological gases and solid material in powder form and method to use the integrated device for the metallurgical processing of baths of molten metal
US6514310B2 (en) Process for injection of a gas with the aid of a nozzle
US6176894B1 (en) Supersonic coherent gas jet for providing gas into a liquid
RU2474760C2 (en) Method to generate burning by means of assembled burner and assembled burner
JP5551086B2 (en) Combined burner and lance for electric arc furnace
US20030075843A1 (en) Multi-purpose, multi-oxy-fuel, power burner/injector/oxygen lance device
CN102812136A (en) Copper anode refining system and method
KR100937947B1 (en) Method for the pyrometallurgical treatment of metals, metal melts and/or slags and injection device
KR19990045403A (en) Coherent Jet Injector Lance
CN110042199A (en) Stir air port and method in bottom for basic oxygen furnace
CN105612263A (en) Top submerged injection lance for enhanced submerged combustion
CN105950824A (en) Electric arc furnace steelmaking process with oxygen, fuel and powder common injection
US8377372B2 (en) Dynamic lances utilizing fluidic techniques
JP3604698B2 (en) Oxygen blowing / fuel burner combination lance assembly
WO2011073760A1 (en) Injection device and relative operative method
KR20070012478A (en) Refining molten metal
US8992656B2 (en) Controllable solids injection
KR101765333B1 (en) Multi-thermal type sandwich burner unit of flame gunning machine
CN102878797B (en) Shaft furnace and its operating method
KR101511178B1 (en) Method for the pyrometallurigical treatment of metals, molten metals, and/or slags
JP2020094247A (en) Lance for refining, lance apparatus for refining, electric furnace, and steelmaking process
CN101310027B (en) Tuvere tuyere of melter-gasifier
KR20130112021A (en) Method and system of removing accretion buildup in a furnace
JP2807165B2 (en) Oxygen burner
SU1305177A1 (en) Method for flame concrete spraying of converter lining and gun for effecting same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10807659

Country of ref document: EP

Kind code of ref document: A1

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 10807659

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 10807659

Country of ref document: EP

Kind code of ref document: A1