Abstract: First and second feed streams are injected into a molten bath, thereby creating first and second jets. The first and second jets combine to form a substantially planar, or fan jet, region within the molten bath. The first and second feed streams can include a variety of materials, such as oxidant, reducing agents, or waste materials, such as organic waste. In addition, the feed streams can include distinct reactants that are combined in the fan jet region for reaction with each other or with one or more components of the molten bath.

Abstract: A purging device for use in metal processing includes a shell, a body and a plurality of gas delivery tubes. The body comprises a refractory material and the tubes are disposed therein. Each tube has at least two passageways extending therethrough. The body with the tubes disposed therein is placed in the shell such that there is a gap between a portion of the body and the shell. An inlet allows the device to be attached to a lance, ladle or similar apparatus. Gas flows through the inlet, into the shell, through the passageways in the tubes and into the molten metal. In this manner, gas is delivered through the purging device through a plurality of passages that are arranged in discrete groups.

Abstract: An apparatus for and a method of melting fine particles containing carbon, capable of uniformly burning and melting the fine particles throughout the entire zone of the combustion flame. The apparatus includes a triple tube structure including an inner oxygen feeding section having an oxygen inlet tube provided with an oxygen feeding passage, a particle feeding section arranged surrounding the inner oxygen feeding section, comprising a particle inlet tube, a feeding tube and a feeding passage, and an outer oxygen feeding section arranged surrounding the particle feeding section, comprising an outer oxygen inlet tube, a feeding tube and a feeding passage. The front ends of the inner oxygen feeding tube, particle feeding tube and outer oxygen feeding tube constitute a nozzle which serves to inject the fine particles fed through the particle feeding tube together with air and/or oxygen flows respectively fed through the inner and outer oxygen feeding tubes to be burned and melted.

Abstract: A high-speed jet of liquid oxygen (21) with a speed higher than 100 meters per second is delivered into the tuyeres of a blast furnace of cupola furnace together with pulverised carbon. The jet reaches the opposite wall of the cavity (9) formed at the outlet of the tuyere (6) in the mass of material contained in the shaft. Supplying oxygen to the bottom of the cavity improves the burning of the remaining coal, whereby higher injection levels may be achieved. The shape of the cavity may also be altered, and, in particular, faster reactions may be achieved in the axial region of the shaft.

Abstract: To increase the service life of a tuyere arrangement for the introduction of agents into a molten bath, comprising an apertured block (3) refractory material which can be fitted into the wall (1) of a vessel (12) and which includes a cylindrical body (4) with an inserted tuyere tube (6,7), the cylindrical (4) is axially displaceably fitted in the apertured block (3) the tuyere tip which is consumed is replaced by a follow-up movement of the cylindrical body (4).

Abstract: A tuyere for refining molten metals or melting metal scrap or oxides charged into a vessel. The tuyere comprises three concentric pipes of copper or stainless steel encased in refractory. An annular stream of natural gas surrounds an annular stream of oxygen which in turn surrounds a core stream of natural gas. All three streams are expanded as they flow through the tuyere and as a result an accretion forms at the tip of the tuyere. The accretion protects the tuyere and the gas streams are controlled so that the accretion is maintained at a desired size which neither blocks the tuyere, nor permits burnback of the pipes.

Abstract: A method and device is provided for the combined injection of pulverized coal and a gaseous oxidant into a crucible of a shaft furnace, especially a blast furnace, through a hot-air blast tuyere. In the region of the nozzle end of the tuyere in the crucible, the pulverized coal is injected into the hot-air blast, in the form of a hollow annular jet and the gaseous oxidant is injected inside the hollow annular jet. A lance for implementing the method comprises two coaxial tubes and a distributing unit provided with a central bore for the pulverized coal.

Abstract: A method and apparatus are disclosed for injecting liquids into a molten bath. The method includes forming a suitable liquid dispersion of a liquid phase disposed in a gas phase. The liquid phase has a ratio of surface area to volume which is sufficient to cause an accumulated amount of the liquid phase in the molten bath to be significantly less than that which would occur by injection of a continuous stream of the liquid into the molten bath. The liquid dispersion is directed into the molten metal bath, whereby the liquid volatilizes or decomposes. The rate at which the liquid dispersion is injected into the molten bath is sufficient to cause the liquid of the liquid phase to volatilize or decompose at a rate which is sufficient to cause the accumulation of the liquid phase in the bath to be significantly less than that which would occur by injection of a continuous stream of the liquid into the molten bath. The apparatus includes an atomizer which is disposed at a reactor containing the molten bath.

Abstract: A first flow of gas (C) accompanying a flow of solid particles (S), is sent at supersonic speed into a first conduit (1) prolonged by a third conduit (8) and intersecting a second conduit (6) supplying a second flow of gas (G) which is deflected into the third conduit (8) to accompany the flow of particles (S) whose trajectory is not substantially modified, the flow of the first gas (C) being deflected, downstream of an oblique shockwave (13) into a fourth conduit (9) forming a separator nose (10) with the third conduit (8). The invention is particularly applicable to the injection, into a reaction chamber (16), of solid particles with a highly oxygenated gas (G) replacing an inert gas (C) for conveying the particles.

Abstract: The invention relates to a method and an apparatus for sealing tuyeres and feed pipes installed in a refractory vessel lining. Seals known per se, in particular prestressable packings, are installed in the gap between the tuyere or feed pipe and the surrounding refractory material in order to avoid backflow of media.

Abstract: To heat a thermic enclosure, flames are generated in a burner having a plurality of injectors, from an oxy-combustible mixture, the flames extending in different directions and having different power and/or oxidizing reducing capacity. Application for example to the heating of furnaces or metallurgical ladles or glassware furnaces.

Abstract: A tubular water-cooled jacket for furnaces is disclosed which includes a tubular member having a plurality of axial apertures and a plurality of transverse apertures. Each transverse aperture is formed therein so as to bring at least two of the axial apertures into open comunication with each other. The plurality of axial apertures and the plurality of transverse apertures corporate with one another to define a plurality of fluid passageways for cooling water isolated from one another. Each of the fluid passageways may be defined by at least two of the axial apertures and at least one of the transverse apertures connected to the at least two axial apertures. The tubular member may include a plurality of segments arranged side-by-side in a circumferential direction thereof and joined together.

Abstract: An injection block of an injection valve intended for bottom injection but optionally operable on the side of a teeming vessel for side injection is disclosed. The invention is directed specifically to a multi-passageway multi-orifice injection block in which the injection passages may be parallel, radially disposed around a frustoconical locus, or angled in a tangential fashion within the injection block. The thrust of the invention, however, is to stage the permeable elements in progressively more buried relationship to the hot face of the injection block sequenced in the order in which the particular passageways which are plugged by the porous plug are programmed for use. In this manner, progressive erosion of the wet or hot face of the injection block will progressively expose the upper portion of the permeable plug in accordance with the timed usage intended for the same.

Abstract: An injection block of an injection valve is disclosed which is normally intended for installation in a metallurgical vessel or holding vessel containing ferrous metal. Other metals can be similarly treated by injection metallurgy, but the maximum utility is believed to be involved in the processing and metallurgical finishing of ferrous metals. The injection block is provided with orifice passages terminating in orifices through which the injections are gas driven, wire fed or in pellet form inserted into the molten metal in the vessel. The orifice passages are angled in one of two directions or a combination of the two directions, radially relative to the axis of the injection block and/or tangentially away from an element that is parallel to the axis of the injection block so as to circumvolve the axis of the injection block.

Abstract: Nozzles for a refining lance are presented which are spaced upwardly from the head of the lance and supply post-combustion oxygen to the space above a molten metal bath undergoing refining. Each of the nozzles has a mouthpiece with two parallel sharp edges which are arranged in planes passing substantially through the axis of the lance and which are connected by slightly rounded edges. Above the mouthpiece of each nozzle is a converging part.

Abstract: The invention relates to a flushing block for introducing gaseous and/or solid reagents and additives into a metallurgical melting vessel, which is connectable at one end to a gas pipe and at least to a drive means and at its other end has at least one outlet opening extending from its circumferential surface, said opening terminating in at least one gas channel which can be connected to the gas pipe.

Abstract: A tuyere for a metallurgical vessel comprising a solid metal tuyere body with a central gas feed bore. The gas feed bore contains at least one gas feed pipe. The tuyere body also has at least one water-cooled bore between the outer wall of the tuyere body and the gas feed bore. A water-cooled bore has a water passage for circulating water therethrough. A water cooling header with separated water inlet and outlet is attached to the tuyere body external to the metallurgical vessel. A water passage is provided for a flow of water from the water inlet through the water passage in the water-cooled bore to the water outlet. The cooling capacity of the tuyere is sufficient to cause the formation of a protective encrustation on the end of the tuyere, and to effectively reduce erosion and chemical reaction of the tuyere material and the vessel wall.

Abstract: This invention concerns the burning of fuels, such as natural gas, at high temperatures. The invention includes a high-efficiency burner which achieves substantially complete combusiton at modest cost. The burner of the present invention includes a generally cylindrical housing having a central bore and two concentric annular regions. A lance is inserted through the central bore, and protrudes slightly from the front face of the burner housing. The fuel is directed through the inner annular region, and oxygen-enriched combustion air is directed through the outer annular region. Substantially pure oxygen is directed through the lance. The gases in the lance and the annular regions do not communicate with each other within the burner housing, and all burnign takes place outside the housing. The same supply of oxygen can be used to supply the lance and to enrich the combustion air.

Abstract: A tuyere having improved wear resistance at the tip, and a refractory walled metallurgical vessel incorporating the tuyere, characterized by an oxide thermal barrier coating on the outer surface of the outermost conduit of the tuyere having a thermal conductivity less than that of the refractory.

Abstract: A consumable lance for injecting oxygen and other gases such as argon below the surface of a molten metal bath the lance comprising an upper manifold portion, a lower nozzle end portion, and a plurality of gas conveying conduits attached to a structural support assembly and encased within a protective refractory covering.

Abstract: An assembly for use in supplying a gas through a metallurgical vessel into molten metal contained therein includes a refractory supporting block to be mounted within a wall or a bottom of the metallurgical vessel. The supporting block has an inner end directed toward the molten metal and an outer end directed outwardly of the metallurgical vessel. A plurality of receiving chambers extend into the supporting block from the inner end thereof, and each of a plurality of purging bricks is fitted within a respective receiving chamber. A connecting plate is mounted on the outer end of the supporting block for connection to a source of purging gas. A plurality of channels extend through the supporting block from the connecting plate to respective of the receiving chambers and purging bricks.

Abstract: For injecting substances into a liquid e.g. molten metal, a nozzle block is mounted in the wall of a vessel containing the liquid. Initially, an injection passage extending through the block is closed by a plug to prevent ingress of liquid, and only when injection is to commence is the plug thrust aside by a delivery pipe movable in the passage, the pipe forming part of an injection lance assembly. The positions of the lance assembly before and after injection are determined by a safety stop arrangement for example comprising a detent in the form of a spring-loaded plunger housed in a fixed part of the apparatus; the plunger coacts with front and rear ramps of an abutment which is fast with part of the lance assembly, to govern the positions of the lance assembly before and after injection.

Abstract: A tuyere is disclosed which is adapted for the injection of gases into a metallurgical vessel. The tuyere includes inner and outer concentric tubes having a radial separation therebetween which defines an annular gap. In use, one gas such as an oxygen mixture flows through the center of the inner tube, and a second normally inert gas flows through the annular gap between the two tubes. In order to provide a closely predetermined and predictable gas flow rate through the annular gap, annular groove is formed in the wall of the outer tube which forms an annular restriction in the gap, and the extent of the restriction may be calibrated so as to provide a closely predetermined gas flow rate therethrough when in use. An annular groove may also be formed in the wall of the inner tube to provide a predetermined restriction in the gas flowing through the inner tube.

Abstract: A multiple orifice injection valve having a stationary block which communicates between the vessel and a sliding plate. The sliding plate is provided with at least one injection port and drive means for rotatably indexing the same in and out of register with the various orifices in the stationary block. Both the stationary block and sliding plate may have special wear features. The sliding plate is held by means of a carrier, and the same urged by a plurality of spring-loaded rockers into pressure face-to-face relationship with the stationary block. The valve can be open by a toggle latch and toggle hinge assembly thereby permitting removal of the sliding plate and/or the stationary block. Injection is provided by a quick disconnect coupling having two injection ports. The one port receives wire or other metallic material in wire form, and the second port injects gas, powdered metals, or other fluid-like materials.

Abstract: A tuyere assembly and positioning method comprising mechanically separate or separable inner and outer tubes, the inner tube(s) being removeable and replaceable and the outer tube being extendable into a vessel and held in place by a flared end abutting the wall of a cavity through the vessel wall.

Abstract: A water-cooled lance for blowing oxygen or oxygen containing gas onto a metal melt, for example an iron melt, for afterburning reaction gases from the melt and transfering the heat of afterburning back to the melt comprises a center tube forming a gas supply duct surrounded by further tubes for cooling water. The center tube leads to a head having a plurality of oxygen-blowing nozzles. Each of the nozzles has a plurality of oxygen outlet openings. The outlet openings have their centers lying on two concentric circles and are arranged so that each opening produces an individual gas stream. The axes of the outlet openings are inclined to the longitudinal axis of the lance at angles such that, in a plane perpendicular to the longitudinal axis of the lance and at a distance Lh from the head, the gas streams extend over an annular area in the plane having an inside diameter Di and and outside diameter Da. Lh, Di and Da have the following relationships:Di:Lh is the range of from 0.15 to 0.

Abstract: A multi-purpose pyrometallurgical process enhancing device for metallurgical furnaces can be employed in oxy-fuel burner mode for preheating and melting of solid charge, in an oxygen injecting lance mode for decarburization of molten metal in metallurgical furnaces, in particular in melting electric arc furnaces, plasma arc furnaces and basic oxygen furnaces, and in an injector mode for injecting solid materials; the device includes a pivotally mounted water cooled generally arcuate body which can be pivoted into and out of a furnace vessel through a small opening in the shell wall for optimal positioning of the oxy-fuel flame against solid charge, in the burner mode; or injection of oxygen vertically downwardly into the molten metal at supersonic speed, in the oxygen lance mode; in one embodiment the arcuate body can be rotated about its longitudinal axis for directing the oxy-fuel flame towards a cold spot in the furnace; the tip of the arcuate body includes a replaceable, multi-opening nozzle, mounted in a

Abstract: A blowing apparatus for simultaneously delivering gaseous and solid materials to a hot metal melt during refining is presented. The blowing apparatus or blowing lance provides a novel structure of an inner block, an outer block housing, and tubing wherein incompatible materials (i.e., oxygen and carbon) may be safely and simultaneously delivered by use of a protective structure which also functions as a cooling device. The blowing lance further includes a variety of nozzles for blowing materials both above and below the surface of the metal pool.

Abstract: The present invention relates to a concentric multi-tube-system nozzle situated beneath the surface of the melt in a refining vessel, especially a refining vessel for converting molten pig iron into steel.The stability and life of the concentric double-tube nozzle is the most crucial factor in carrying out refining in a bottom-blown converter.In accordance with the present invention, there is provided a concentric multi-tube-system nozzle situated beneath the surface of the melt in a refining vessel, comprising:an inner tube;an outer tube positioned concentrically with respect to the inner tube and forming an annular clearance between the inner tube and the outer tube;spacers for circumferentially dividing the annular clearance; anda section defined by two adjacent spacers, the section comprising a contraction portion which is positioned essentially at the upstream side of the section. The contraction portion contributes to a uniform cooling of concentric double-tube nozzle in the circumference thereof.

Abstract: The invention relates to a refining lance used in blowing some additive into molten metal in a vacuum vessel when molten metal, such as molten steel, refined by employing a converter or electric furnace or the like is further refined into a metal having the desired composition. The lance includes a center hole for jetting the additive in the presence of gas and a plurality of side holes (Laval nozzle holes) for supply of accelerating gas so as to have the additive effectively added to the molten metal. The invention also proposes a method for producing low-carbon high-purity steels in molten state by using the refining lance.

Abstract: A device for blowing gas and a finely-divided solid into a metallurgical melt is disclosed, the device having a blast pipe which has at one end an inlet connected to a gas source and at the opposite end an outlet immersed below the melt surface in order to blow the gas into the melt. A cooling device surrounds the blast pipe, the cooling device having, at that end which is near the blast-pipe inlet, inlets and outlets for the cooling medium, and a mantle of ceramic material which surrounds at least the lower part of the cooling device. In the outlet of the blast pipe there is a Laval nozzle which is at an angle to the blast pipe and extends through the thermally insulating mantle.

Abstract: Tuyere for the processing of metals in the liquid, solid or pasty state, and capable of introducing simultaneously and separately a gas and a powdered material. The tuyere comprises at least two well-centered concentric tubes, the gas being introduced into a non-external tube, and the powdered and compressed material being introduced into another tube, which is lubricated on its inner wall by a film of a lubricating substance introduced through a slot formed therein. The outer tube is traversed by an agent protecting the tuyere against its hot wear.

Abstract: In a method for cooling tuyeres when molten iron is refined by blowing a refining gas containing oxygen, and by setting tuyeres below or above the meniscus of iron bath in a vessel for refining the molten iron, wherein concentric tuyeres are used and a refining gas containing oxygen gas is blown through the inner pipe of the concentric tuyere and a fluid for protecting the tuyeres is blown through the outer pipe of the tuyere so that the protecting fluid surrounds the refining gas in a sheath form to cool the top ends of the tuyeres, the protecting fluid being a mixture of gaseous or liquid carbon dioxide and carbon fine particles.

Abstract: A holder for an oxygen lance characterized by at least one actuating device comprising an operating lever which is connected to a shut off valve.

Abstract: A generally cylindrical lance is fitted with a nozzle block, extending into a recess formed at the downstream end of the lance. Within the lance are formed concentric gas feed tubes, which are placed in individual fluid communication with flow passages through the nozzle block. The nozzle block is sealingly connected to the open downstream ends of the gas feed tubes such that the mixture of gases from the respective tubes within the lance is prevented. The nozzle block is provided with an interchangeable jet nozzle element to provide a high-speed central gas flow. Located about the central nozzle, preferably in a concentric fashion, are outer nozzle means through which gas or gas mixtures pass at a relatively slower speed. Gases emerging from the nozzle block flow in a parallel fashion, such that the gases may mix or combine at the point of incidence on a molten bath surface. A flow change-over arrangement enables a different gas to be passed through at least one nozzle means as desired.

Abstract: Improvements in multiflow refining blastpipes for equipping converters for refining and including at least two concentric tubes 1 and 3, which define between them an annular gap 4 and an annular ring 8 connected by welding onto the outer tube 3, which consist in arranging at the end of the outer tube 3 which is located next to the inlet for the fluids into the blastpipe, a shoulder 12 prolonged by a cylindrical portion 13 which defines an annular chamber 14 for the introduction of a protective fluid, and in arranging the annular ring 8 on the said cylindrical portion 13.

Abstract: A tuyere for the injection of both a refining gas such as oxygen into a melting or refining vessel, and a fluid protective medium such as a hydrocarbon gas or a liquid surrounding the injected refining gas, in which there is a solid center in the pipe through which the refining gas is suplied so that the refining gas enters the refining vessel as an annulus around which the protective fluid is disposed.The tuyere is installd in the refractory lining of the refining vessel and the fluids passing into the vessel through the tuyere are proportioned so that burning back of the tuyere and erosion or wear of the lining take place at the same rate.The protective medium cools the tuyere and avoids reactions between the refining gas and the tuyere material.

Abstract: A plural nozzle arrangement is provided for introducing reactants, additives and so forth to steel manufacturing furnaces, in which a unitary "plug-in" type structure is provided with a plurality of self-contained blast pipes. The arrangement of the invention also provides means for introducing separately additives, reactants or shielding gases around the periphery of the blast pipes as a secondary means of introduction while still contained on the unitary structure. The unitary structure of the invention is so configured that exposure of the periphery of the individual blast pipes to the secondary additives may be varied for different applications.

Abstract: An improved construction for the refining gas passage of a tuyere for use in refining molten metal in a converter. The transverse section of the refining gas passage has a continuous outer enclosure and a central opening defining a plurality of radially extending branches whose total perimeter exceeds the circumference of a circle having an area equivalent to the central opening.

Abstract: Method and apparatus for measuring gases dissolved in molten metal. Also disclosed are method and apparatus for dissolving gases in molten metal and a method of forming a gas permeable but molten metal impervious ceramic tube. A ceramic member is leached by an invention process so as to be selectively gas permeable. The member is inserted into molten metal to submerge the permeable portion. Then a vacuum is applied to the member and dissolved gases are measured by the change in pressure caused by gases entering from the molten metal. In another embodiment gas is applied to the submerged member to cause it to dissolve in the molten metal.

Abstract: A device comprises tuyeres at the bottom of the converter and a cylindrical manifold for fluids and powdered products disposed in the center part of and under the bottom of the converter. Connecting pipes between the manifold and the tuyeres are disposed radially around the manifold. The connecting pipes have the shape of a lyre with a closed loop.

Abstract: In the blowing of smelting shaft furnaces tuyeres are used which are not water-cooled and which comprise three concentric conduits leading directly into the furnace, the central conduit receiving the hot blast, the intermediate conduit receiving an oxidizing gas which is not preheated and the outer conduit receiving a fluid or emulsion containing hydrocarbons.

Abstract: A charge is admitted into a shaft furnace so as to form a charge column therein. The lower end of the column is melted with a flame and the charge moves downwardly by gravity as melting proceeds. The flame is generated by admitting one or more streams of oxygen and one or more streams of fuel into the furnace. A stream of oxygen and a stream of fuel are admitted into the furnace as a pair and in such a manner that the respective oxygen stream is surrounded by the respective fuel stream. This procedure provides the result that the fuel entering the furnace withdraws so much heat from the surroundings that water-cooling of the burners may be eliminated. Moreover, the withdrawal of heat from the surroundings serves to cool the furnace wall in the regions of the burners sufficiently for molten material flowing on the furnace wall in these regions to solidify. Consequently, protuberances are formed on the furnace wall.

Abstract: An improvement in the refining of molten metals in a converter by means of oxygen introduced into the metal through tuyeres which include two concentric pipes, oxygen being passed into the melt through the central pipe and a protective fluid being passed into the melt as a sheath or screen around the oxygen, through the clearance space between the two pipes. In the present invention two tuyeres, disposed horizontally and each passing through the convertor sidewall permit refining to be accomplished without any slopping or splashing of the melt and with only minor wear of the convertor lining.

Abstract: A blast pipe is formed of a plurality of concentric tubes, the cross-sections of which are designed for the fluid flows required for the refining of a metal bath, which are used initially as a burner. A second tube adjacent an outermost tube, projects beyond the end of the outermost tube, and is provided with a row of orifices in the projecting portion. The end of the second tube is closed by a metal cap soldered to the second tube with a hard solder which melts at a predetermined temperature in relation to the metal of the bath to be refined.

Abstract: Blast furnace tuyere comprising three separate injection chambers, a first axial chamber for injecting hot blast, a second narrow annular chamber concentric therewith for injecting fuel oil and a third annular chamber concentric with the other two for injecting oxygen mixed with cold air. This tuyere dispenses with a water cooling circuit.

Abstract: A blast pipe assembly for mounting on attachment to and dismounting from the bottom plate means of a converter or furnace for refining metals, the plate means including a hollow cylindrical part for surrounding the blast pipe and having at its lower end portion an inner shoulder and a flange for clamping bolts, the blast pipe assembly comprises two concentric pipes for double separate feed, the inner pipe of said concentric pipes being longer than the outer pipe of said concentric pipes and the inner diameter of said outer pipe being greater than the outer diameter of said inner pipe to define a gap between said pipes for admission of fluid, the lower end of said outer pipe, which is arranged to be at the level of said shoulder of said hollow cylindrical part, being flared, said inner pipe having, at a level below the lower end of said outer pipe, a circular swelling;A hollow cylindrical injector body adapted to be arranged between said flared portion of said outer pipe and said circular swelling on said inne

Abstract: A tuyere assembly for use in metallurgical vessels includes a tubular metallic tuyere housing which is cast in a block of refractory material. When the tuyere block is installed in a metallurgical vessel, a tuyere is inserted within the tubular tuyere housing and the space between the tuyere assembly and the housing sealed with a suitable refractory material. After a significant portion of the tuyere assembly has burned away during metallurgical operations, the tuyere may be withdrawn from the tuyere housing and a new tuyere substituted. Any refractory lining which has burned away in the vicinity of the new tuyere may be built up with a chemically bonded gunning mixture which sets to form a dense refractory material around the tuyere assembly.

Abstract: This invention relates to a process for refining metals in a refining vessel, by means of a tuyere embedded in the bottom or sidewall of the vessel and through which a refining gas is blown into the vessel. The tuyere is composed of at least three concentric pipes, the refining gas being made to pass through the central pipe and a protective medium being made to pass into the vessel through the spaces between the pipes which surround the central pipe. All of the pipes except the outermost pipe which is fixedly embedded in the refractory lining of the vessel, are individually movable longitudinally into the vessel.

Abstract: A lance structure for oxygen refining of molten ferrous metal comprising three concentric metallic tubes extending through a side wall of a reaction vessel and terminating in a common discharge plane beneath the molten metal surface adjacent the side wall, the innermost tube conducting an oxygen-containing gas, the annular space between the innermost and second tube conducting a shroud gas, a pair of parallel auxiliary cooling pipes in another annular space between the second tube and the outermost tube for conducting cooling gas, the pipes being on opposite sides of the second tube in the 3 o'clock and 9 o'clock positions, and refractory material encasing the pipes and occupying the other annular space, the pipes being sufficiently remote from the second tube that cooling gas discharged therefrom does not intermingle with the oxygen. A method of oxygen refining molten steel is disclosed utilizing such a lance structure.