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
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
  • C21C5/28—Manufacture of steel in the converter
  • C21C5/42—Constructional features of converters
  • C21C5/46—Details or accessories
  • C21C5/48—Bottoms or tuyéres of converters
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F27—FURNACES; KILNS; OVENS; RETORTS
  • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
  • F27B3/00—Hearth-type furnaces, e.g. of reverberatory type; Electric arc furnaces ; Tank furnaces
  • F27B3/10—Details, accessories or equipment, e.g. dust-collectors, specially adapted for hearth-type furnaces
  • F27B3/22—Arrangements of air or gas supply devices
  • F27B3/225—Oxygen blowing
• • 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
  • F27D3/16—Introducing a fluid jet or current into the charge
  • F27D2003/162—Introducing a fluid jet or current into the charge the fluid being an oxidant or a fuel
  • F27D2003/163—Introducing a fluid jet or current into the charge the fluid being an oxidant or a fuel the fluid being an oxidant
  • F27D2003/164—Oxygen
• • 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
  • F27D2003/168—Introducing a fluid jet or current into the charge through a lance
• • 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 invention relates on the one hand to a metallurgical melting vessel, this term encompassing all containers in which molten metal is formed, treated and / or transported.
• a melting vessel can be, for example, a ladle, an SM oven (Siemens Martin oven) or an electric oven.
• the invention further relates to a method for the secondary metallurgical treatment of a molten metal in a melting vessel designed according to the invention.
• Devices for introducing gases and / or solid reaction and additives into a metallurgical melt have been known for decades. The purpose of these treatments is the physical and / or chemical
• ceramic gas purging stones which are designed with non-directional or directional porosity.
• static channels run through the sink, which is installed in the wall or in the bottom of the melting vessel.
• the device according to WO 93/09255 consists of a ceramic refractory casing in which two pipes arranged concentrically to one another run.
• the device is installed exactly horizontally in the wall of a metallurgical melting vessel. Treatment media are fed into the molten metal through the inner tube or an annular gap between the inner and outer tubes.
• the two metal pipes can be adjusted in the direction of the molten metal. The service life of the facility is extended accordingly.
• a disadvantage of the known device is that it must always be aligned exactly horizontally, since the ceramic covering and tubes lie loosely on a pressure plate at the end which projects beyond the melting vessel on the outside. An inclined arrangement would cause the pipes to slide into the melt in an uncontrolled manner. Otherwise, the nozzle device according to WO 93/09255 has proven itself and forms the current state of the art. Nevertheless, there is a constant need to optimize facilities of the type mentioned with regard to their service life and possible uses.
• the axially displaceable part of the device should be guided in such a way that it is not only axially displaceable in the direction of the molten metal, but also in the opposite direction.
• the inner end of the device projects beyond the refractory lining of the melting vessel.
• the outlet end of the nozzle device projects into the interior of the melting vessel and usually thus into the molten metal. In the prior art, this was also the case when the melt was drained.
• charging e.g. metal scrap
• a corresponding mounting or storage and guidance of the components of the device is required, as described below. It may also be advantageous to coat the components with a substance that has a lower wetting gradient than the molten metal.
• An essential area of application of the nozzle device described is the supply of oxygen to a molten metal. This is done for example via the inner tube. In the direct contact area with the molten metal, extremely high temperatures can develop, which can reach and exceed 2000 degrees. The result would be rapid wear of the nozzle device and the neighboring refractory material.
• WO 93/09255 already suggests guiding a protective gas along the ring channel between the inner and outer tube, which surrounds the oxygen in the manner of a concentric jacket, and also in the outlet area from the nozzle device.
• a protective gas can be an inert gas such as argon.
• a cooling gas such as ' CH 4 (methane) can also be used.
• the reaction area of the oxygen with the molten metal is permanently moved away from the inner wall of the melting vessel and the area around the nozzle device is cooled. In this area, however, a so-called "protective mushroom” can develop. This is an accumulation of solidified steel, slag and foreign substances in the immediate vicinity of the nozzle device at the outlet end and in particular in the contact area with the inner wall of the refractory lining of the melting vessel.
• Such a protective mushroom can hinder the advancement of the nozzle device into the molten metal. It can also happen that due to the mechanical anchoring of the mushroom with the nozzle device on the one hand and the refractory wall area of the melting vessel on the other hand, lining material is torn off when the nozzle is pushed forward. All of these effects are undesirable.
• the approach of the invention aims to guide the nozzle rotatably in the lining of the melting vessel. With a corresponding shear stress between the support mushroom and the inner wall of the lining, the support mushroom can be removed relatively easily. Tearing off refractory material can largely be avoided.
• the rotatability of the nozzle in particular in connection with the axial guidance of the nozzle mentioned above, has another very important advantage:
• the nozzle can now also be installed in the furnace wall at an angle, that is to say it is inclined in the direction of the melt. Because it is held on the outside, it can no longer slide into the melt. With such an arrangement, however, uneven wear (in the radial direction) can occur at the inner end. This can now be compensated for by rotating the moving parts of the nozzle device from time to time by a certain angle. The less worn zones are brought into a position where more wear is to be expected. It is not necessary at this point in time to move the entire nozzle unit axially towards the melt. This can be done later. Overall, this results in a significantly longer service life for the nozzle device.
• the most general embodiment of the invention then relates to a metallurgical melting vessel with a refractory ceramic lining, through which a nozzle device for introducing a fluid into a metal melt extends, the nozzle device having the following features: a tubular refractory ceramic sheathing an outer tube which is arranged coaxially in the sheathing, an inner tube which extends coaxially in the outer tube, at least one axially extending channel being formed between the inner and outer tubes.
• This nozzle device can also be moved axially back and forth, and is rotatably arranged in the refractory ceramic lining of the melting vessel.
• one embodiment provides for a viscous sliding layer to be arranged between the covering of the nozzle device and the refractory lining.
• This sliding layer must not only consist of a lubricant-like material, but also be temperature-resistant. Materials based on graphite or on the basis of molybdenum compounds have proven to be suitable.
• the outer tube can be arranged axially displaceable relative to the casing.
• a sliding layer can again be provided in between.
• the outer tube can also be glued to the casing or connected in some other way.
• Inner and outer tubes can be connected via spacers that do not hinder a flow in the axial direction.
• the nozzle device will usually protrude beyond the refractory lining so that there is sufficient length available to track the nozzle device several times in the direction of the melt.
• the nozzle device can be easily guided axially and rotatably on this part.
• the nozzle device can run, for example, along at least one coaxial sleeve.
• the sleeve can have several functions fulfill: on the one hand it gives an axial guidance, on the other hand it can easily be supported, for example, on the outer wall of the melting vessel.
• an embodiment of the invention proposes to design the region of the nozzle device that extends outside the melting vessel with at least one radially extending widening. This widening serves as a stop when the device is withdrawn. Such a widening can be a circumferential flange.
• the device can be frustoconical at the corresponding end.
• the mounting and guiding of the nozzle device makes it possible, as stated, to arrange the nozzle device in an inclined manner, the lower end opening into the interior of the melting vessel and preferably being below the bath level of the melt: if the other (outer) end is above this bath level, this also provides an advantageous protection against melt breakthroughs in the event that the nozzle device should break.
• the individual movable parts of the device can be movable independently of one another, as will be described in more detail below.
• the melting vessel described makes it possible, for example, to carry out the following secondary metallurgical treatment:
• oxygen is injected into the melt along the at least one channel between the inner and outer tube, a cooling fluid is simultaneously supplied to the oxygen, from time to time the nozzle device is rotated and, if necessary, then additionally pushed into the metal melt, if necessary, the Withdrawn the nozzle device so far that it no longer protrudes over the inner wall of the metallurgical melting vessel, one or more of the aforementioned steps can then be repeated.
• the single figure shows - in a schematic representation - a section through a wall area of an electric furnace, a nozzle device according to the invention being installed in the wall.
• a wall section 10 of the electric furnace can be seen with an inner wall surface 10 and an outer wall surface 10a.
• the inner wall surface lOi runs obliquely to the vertical.
• the wall surface 10a runs vertically.
• the wall 10 consists of a conventional refractory lining. In this lining sits a refractory ceramic perforated brick 22, which is aligned on the outside (at 22a) and on the inside (at 22i) approximately with the outer surface 10a or inner surface 10i of the wall 10.
• an obliquely running bore 24 is provided, which drops from the outer surface 10a to the inner surface 10i. It serves to accommodate a tubular refractory ceramic covering 26.
• the covering 26 is substantially longer than the width of the wall 10, so that the covering projects beyond the wall 10 on the inside and clearly extends beyond the wall 10a on the outside protrudes.
• a lubricant 28 is introduced between perforated brick 22 and the corresponding section of the casing 26.
• An outer tube 32 is assembled within the envelope 26 and has the same length as the envelope 26.
• An inner tube 34 is arranged in the outer tube 32, likewise of the same length.
• the tube 34 has knobs 36 on the circumference at a distance from one another. The knobs 36 serve to keep the inner tube 34 coaxial and at a distance from the outer tube 32 and at the same time form an annular gap 38 between the two tubes 34, 32.
• the nozzle device consisting of the components arranged coaxially to one another: sheath 26, outer tube 32, inner tube 34 is arranged in a circumferential sleeve 40.
• the sleeve 40 consists of two half-shells and lies non-positively on the casing 26.
• the sleeve 40 is guided on two spaced apart bearings 42, 44, which are attached to scaffolds 46, 48 on the outer surface 10a of the wall 10.
• the slide bearings 42, 44 are guided on the stands 46, 48 in the axial direction of the nozzle device, so that they can be displaced in the direction of the arrows L 1 and L2.
• the outer free end 20a of the nozzle device is frustoconical, that is, the diameter of the envelope 26 widens towards the free end, where a flexible oxygen line 50 and a flexible methane gas line 52 supply oxygen into the inner tube 34 and methane into the annular gap 36, respectively ,
• the nozzle device 20 While there is molten metal in the furnace vessel, which is then drained off, the nozzle device 20 is moved in the direction of the arrow L2 until it no longer protrudes beyond the inner surface 10i. During the subsequent charging, for example of scrap, the nozzle device no longer protrudes into the melting vessel and can no longer break off. As soon as the furnace space is filled with melt, the nozzle is advanced in the direction of the arrow L1 (by moving the bearings 42, 44), for example, until the tip protrudes about 50 to 250 mm above the inner surface 10. The secondary metallurgical treatment can now begin. This is done analogously to the prior art, as described, for example, in WO 93/09255.
• a so-called protective mushroom can be formed, which is indicated by the reference number 60.
• the nozzle device 20 is rotated by activating the rotary bearings 42, 44 by an angle of, for example, 5, 10 or 30 degrees, the protective mushroom detaching from the inner surface 10.
• the entire nozzle device 20 can then optionally be advanced a little in the arrow direction L1.
• a similar effect can be achieved by reducing the coolant supply
• the nozzle device 20 is rotated by approximately 180 degrees (with the aid of the bearings 42, 44) until the wear profile shown in dotted lines in the figure is obtained. In this position, the device can continue to be operated for a while without having to push it in the direction of arrow L1.
• the end 20a of the nozzle device 20 is above a fill level (bath level) X of a metal melt S, the end 20s is below the bath level X.
• the device 20 can easily protrude 150 or 300 mm deep into the melt S, since it can be withdrawn completely if necessary (e.g. when filling the vessel).
• the ceramic covering can be firmly connected to the outer tube, but can also be arranged to be movable relative to the latter.
• the casing with the pipes is then either moved or the pipes are moved relative to the fixed casing.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Metallurgy (AREA)
• Manufacturing & Machinery (AREA)
• General Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Organic Chemistry (AREA)
• Furnace Charging Or Discharging (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Carbon Steel Or Casting Steel Manufacturing (AREA)
• Furnace Housings, Linings, Walls, And Ceilings (AREA)
• Vertical, Hearth, Or Arc Furnaces (AREA)
• Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=28685404

Family Applications (1)

Country Status (11)

Citations (2)

Family Cites Families (4)

• 2002
  • 2002-11-11 DE DE10252276A patent/DE10252276C1/de not_active Expired - Fee Related
• 2003
  • 2003-04-11 UA UAA200505510A patent/UA80167C2/uk unknown
  • 2003-11-04 WO PCT/EP2003/012273 patent/WO2004044511A1/de active IP Right Grant
  • 2003-11-04 EA EA200500714A patent/EA006910B1/ru not_active IP Right Cessation
  • 2003-11-04 TR TR2005/01409T patent/TR200501409T2/xx unknown
  • 2003-11-04 CZ CZ20050257A patent/CZ299214B6/cs not_active IP Right Cessation
  • 2003-11-04 CN CNB2003801030273A patent/CN100408957C/zh not_active Expired - Fee Related
  • 2003-11-04 AT AT0925903A patent/AT501486B1/de not_active IP Right Cessation
  • 2003-11-04 AU AU2003283346A patent/AU2003283346A1/en not_active Abandoned
  • 2003-11-04 PL PL377177A patent/PL204031B1/pl not_active IP Right Cessation
• 2005
  • 2005-04-29 LV LVP-05-53A patent/LV13354B/lv unknown

Patent Citations (2)

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