[go: up one dir, main page]

WO2009087183A1 - Refroidissement d'un récipient de réduction par fusion métallurgique - Google Patents

Refroidissement d'un récipient de réduction par fusion métallurgique Download PDF

Info

Publication number
WO2009087183A1
WO2009087183A1 PCT/EP2009/050150 EP2009050150W WO2009087183A1 WO 2009087183 A1 WO2009087183 A1 WO 2009087183A1 EP 2009050150 W EP2009050150 W EP 2009050150W WO 2009087183 A1 WO2009087183 A1 WO 2009087183A1
Authority
WO
WIPO (PCT)
Prior art keywords
slag
layer
bath
refractory lining
molten metal
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/EP2009/050150
Other languages
English (en)
Inventor
Emile Lonardi
Jean-Luc Roth
Paul Tockert
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Paul Wurth SA
Original Assignee
Paul Wurth SA
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 Paul Wurth SA filed Critical Paul Wurth SA
Publication of WO2009087183A1 publication Critical patent/WO2009087183A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • 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
    • F27B3/24—Cooling arrangements
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
    • C21B13/0013—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state introduction of iron oxide into a bath of molten iron containing a carbon reductant
    • 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
    • F27B3/20—Arrangements of heating devices
    • F27B3/205—Burners
    • 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
    • F27D3/18—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
    • F27D9/00—Cooling of furnaces or of charges therein
    • 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
    • C21C5/56—Manufacture of steel by other methods

Definitions

  • the present invention generally relates to metallurgical smelting reduction vessels and more specifically to cooling their refractory lining.
  • Smelting reduction (SR) in hot metal (pig iron) production involves both reduction and smelting of iron oxides, i.e. melting accompanied by chemical reaction(s).
  • SR processes use two distinct reactors to perform two (or three) subsequent basic steps: partial pre-reduction of the iron oxides (normally in solid state) in the first stage and removal of the remaining oxygen in liquid phase reduction reactions in the second (and third) stage(s).
  • the present invention is concerned with the vessel (reactor) used to perform the second and/or third stage i.e. completion of the reduction and smelting of the iron oxides into hot metal.
  • the latter stage(s) of SR processes typically involve creation of a bath of molten metal and a layer of molten slag on top of the bath in a refractory lined vessel. Reduction reactions occur primarily within the lower region of the slag layer whereas oxidation reactions, in particular post-combustion of CO generated by reduction of the iron oxides in the bath, take place primarily in and above the upper region of the slag layer in order to generate the heat required for driving the process.
  • the slag layer in a SR vessel usually consists of a slag that has a considerable proportion of gas phase, a relatively high basicity (enabling efficient desulfurization of the metal) and an extremely high temperature (since it serves as a site of (post-)combustion heat generation) that well may amount to >1700°C in the region of heat generation of the slag layer (upper region).
  • the slag is commonly referred to as being "foaming" or "foamy” and thus quite voluminous when compared to the volume of the bath, an ample slag volume being beneficial to (post-)combustion and thus energy efficiency.
  • the slag layer above the bath is typically actively agitated, in order to promote post-combustion heat transfer as well as and other reactions occurring within the slag layer by strong turbulence.
  • the refractory lining i.e. the inward brickwork made of heat-resistant material required for containing the high-temperature reactants is subjected to very adverse conditions, especially in the zone of the turbulent slag layer of the SR vessel.
  • Noteworthy sources of considerable wear being mechanical wear from the abrasive washing action of the strongly turbulent molten slag, chemical wear from the slag constituents and thermal wear from exposure to extreme temperatures in the zone of concern.
  • the slag layer itself in turn serves a thermal blanket (avoiding excessive heat loss) and is thus, compared to the slag layer in a SR process, relatively quiescent and usually much less voluminous since it is not required to support (post-) combustion. Furthermore, the thermal load per unit area is typically much less intense in a classic EAF furnace than in an SR vessel.
  • European patent EP 0735146 discloses a specific example of a SR vessel, namely a cyclone converter furnace (CCF). With reference to FIG.2 of this patent, it discloses a CCF smelting reduction vessel (1 1 ) for producing hot metal.
  • the vessel comprises, besides a top part (13) connected to a pre-reduction melting cyclone (12), a bottom part (14) having an outer shell and an inner refractory lining (14, 15) for containing a bath of molten metal (17) and a layer of slag (18, 19) above the bath.
  • the vessel further comprises a bottom gas blowing device for bubbling (24) the bath of molten metal (17) and the slag layer (18, 19) as well as oxidant gas injection devices in the form of oxygen lances (23) for injecting oxygen directly into the slag layer (18, 19).
  • Bottom gas bubbling and (hard blow) oxygen injection allow creating a voluminous and turbulent slag layer (19), which improves transfer of post-combustion heat within the slag layer (18, 19).
  • Carbonaceous material is injected into the slag using gravity-feed chutes (22).
  • the refractory lining (14, 15) has a capacity of at least twice the maximum volume of the bath of molten metal (17) in a SR vessel, e.g. a CCF vessel according to this patent.
  • a SR vessel e.g. a CCF vessel according to this patent.
  • this patents proposes a water cooling installation (16) be arranged in the zone of the turbulent slag layer (19), a major portion of the installation being located above the maximum level of the bath of molten metal (17) for cooling the inner refractory lining (14, 15) in this zone.
  • the suggested cooling is either of the stave-cooler type (FIG.2) or the plate-cooler type (FIG.3), both being part of forced-circulation ducted water cooling systems that are per se well known for cooling blast furnace refractory brickwork.
  • a similar plate-cooler type solution for a SR vessel is disclosed in European patent application EP 1477573. While EP 0735146 and EP 1477573 teach solutions that appear to allow increasing the service life of the refractory lining, these solution are cost intensive in terms of constructional cost.
  • United States patent US 5,708,785 discloses another type of SR vessel. As regards cooling of the refractory lining, this patent proposes restricting cooling to a minimal zone, namely cooling only the portion of the refractory wall above the slag surface between the upper surface of the slag and the furnace charging chute (i.e. above the zone of cooling suggested by EP 0735146) on the ground that cooling on too extensive a scale results in prohibitively high constructional and operational costs.
  • US 5,708,785 basically suggests lowering the hot metal and slag temperatures, the suggested cooling installation aiming at reducing wear related to hot off-gas temperatures and slag spattering above the slag surface. Lowering the process temperatures is however not generally viable in SR process, and thus US 5,708,785 fails to provide a generally applicable solution for extending the refractory service-life, especially in the zone of the turbulent slag.
  • the present invention proposes a smelting reduction vessel for producing hot metal that comprises an outer shell and an inner refractory lining made of brickwork for containing, during operation, a bath of molten metal and a layer of slag above the bath,
  • the vessel includes at least one of the following devices: a bottom gas blowing device for bubbling the bath of molten metal and [he layer of slag; a pneumatic injection device for Injecting carbonaceous materia!
  • the refractory lining is dimensioned to define a capacity of at least twice the maximum volume of [he bath of molten metal contained by the lining. Normally, the height of the refractory lining in an SR vessel as measured from the hearth bottom is at least twice the maximum metal bath level.
  • the vessel according to the invention further includes a cooling installation arranged in the zone of the turbulent siag layer with at ieast a major portion of the installation above the maximum level of the bath of molten metal for cooling the inner refractory lining in this zone, where wear of the lining is most pronounced in an SR vessel.
  • the cooling installation comprises at least one row of copper slabs mounted onto openings provided in the outer shell and so as to be in thermo-conductive contact with the inner refractory lining in the zone of the turbulent slag layer and at least one row of spray cooling devices associated to the row of copper slabs for spraying liquid coolant onto the copper slabs through the openings.
  • the proposed kind of cooling installation allows notable savings in constructional cost compared to known cooling systems for SR vessels.
  • both stave coolers and plate coolers have a relatively high cost per item, whereas the present invention replaces their function by relatively inexpensive massive copper slabs devoid of internal cooling channels (and related circuit connections) using associated external spray cooling means.
  • the cooling installation comprises sensors, e.g. temperature sensors measuring slab temperatures at selected copper slabs, and a process control system to which the sensors are connected and which is adapted to control the spraying of liquid coolant onto the copper slabs and maintaining average or maximum slab temperature below the evaporation temperature of the liquid coolant.
  • the slab temperature is preferably maintained below 8O 0 C 1 more preferably below 8O 0 C during operation.
  • the installation further comprises spraying nozzles with the control system controlling the spraying of liquid coolant onto the copper slabs so as to avoid creation of a continuous coolant film on the copper slabs by creating a plurality of streamlets of coolant trickling on the copper slabs.
  • the refractory lining may comprise MgO or MgO-C based refractory bricks being in thermo-conduclive contact with the copper slabs.
  • the row(s) of copper slabs cover a vertical zone of the refractory lining that extends substantially from the maximum level of the bath, or alternatively from the minimum level of the bath, to at least 1 m (usually as far as 1.5-2m or even further) above this maximum level.
  • a plurality of rows of copper slabs can be arranged one above another so as to extend substantially from the hot metal tapping level (i.e. the minimum bath level) of the vessel to the upper edge of the refractory lining, each row preferably entirely surrounding the refractory lining.
  • spray cooling nozzles with limited spray cone angle e.g. hydraulic spillback nozzles
  • at least two rows of spray cooling devices arranged one above another can be associated to one given row of copper slabs.
  • the smelting reduction vessel may have a refractory lining dimensioned to define a capacity of at least three times the maximum volume of the bath of molten metal and/or with a refractory lining that has a height exceeding the maximum depth of the bath of molten metal by at least 1 m in order to contain the voluminous turbulent siag layer.
  • the invention also concerns the method of operating the SR vessel as set out above in order produce hot metal.
  • carbonaceous material preferably non-coking coal
  • siag layer at a rate of at least 700kg C / (h * m 2 ) for using combustion of carbonaceous material as process heat source.
  • the carbonaceous fuel and reducing agent can be pneumatically injected or gravity fed.
  • the turbulent siag layer is (on spatial average) overheated by at least 100 0 C, possibly >200 ⁇ € with respect to the melting temperature of the molten metal bath, and thereby improves iron smelting and reduction.
  • FIG.1 is a schematic vertical cross sectional view of a first embodiment of a metallurgical smelting reduction vessel according to the invention
  • FIG.2 is a schematic vertical cross sectional view of a second embodiment of a metallurgical smelting reduction vessel according to the invention.
  • FIG.3 is a schematic horizontal cross sectional view of the embodiment of FIG.2;
  • FIG.4 is a vertical cross sectional view of a cooling installation suitable for use in a smelting reduction vessel according to the invention.
  • a smelting reduction (SR) vessel 10 of the oxy-coal smelter type is schematically shown in FIG.1.
  • the SR vessel 10 comprises an outer shell 12 made of steel.
  • the shell 12 is inwardly lined by means of brickwork made of refractory bricks 14.
  • the bricks 14 form a lateral inner refractory lining 16.
  • thermally conductive bricks such as MgO or MgO-C based refractory bricks 14.
  • similar refractory bricks typically also line the bottom of the SR vessel 10.
  • Other parts of the vessel 10, such as the vessel roof 17 and the lateral walls above the refractory lining 16 are protected by other measures e.g.
  • the inner refractory lining 16 defines a crucible, i.e. a reaction space containing a bath of molten metal 18, typically 3-4% carbon content pig iron, and a layer of predominantly liquid slag 20 above the bath during operation.
  • the SR vessel 10 has a charging chute 22 arranged in the vessel roof 17 for gravity feeding raw materials such as a feed 24 of iron ore fines/droplets or other iron oxides into the reaction space defined by the refractory lining 16.
  • the iron oxides in the feed 24 have previously been pre-reduced and pre-heated e.g.
  • a number of oxygen lances 26 are distributed in the SR vessel 10 through the vessel roof 17 or the lateral shell 12 to provide secondary oxygen for post-combustion in the slag layer 20.
  • the oxygen lances 26 are configured to inject a (soft) blow of oxygen 28 directly into the slag layer 20.
  • the blow of oxygen 28 is generally slanting and more precisely directed downwards and toward the centre of the reaction space within the lining 16.
  • the lances 26 can be configured as combined hard blow and soft blow lances additionally providing a high velocity primary oxygen blow (as shown in FIG.2) for enhancing carbon combustion.
  • FIG.1 further shows one of a set of pneumatic carbon injection lances 30 for feeding carbonaceous material such as non-coking coal serving as reductive for iron oxides and as a fuel for heat generation, normally accompanied by flux additives for adjusting the chemical composition of the bath 18 and the slag 20.
  • the injection lances 30 provide a hard blow of pulverized carbonaceous material 32 at high velocity and high pressure i.e. a blow that goes directly into and through the slag layer 20 to penetrate the surface of the metal bath 18.
  • the SR vessel 10 is equipped with bottom gas blowing devices 34, e.g.
  • raw material could be fed by pneumatic injection lances or gravity feed chutes passing laterally through the shell (both not shown).
  • the oxygen injection lances 26 may be replaced by a hot blast or oxygen enriched hot blast injection system.
  • the slag layer 20 is typically strongly turbulent during operation.
  • the required turbulence is ensured by a combination of measures, namely by hard blow injections of carbon, with the blow directions and origins suitably chosen of the lances 30, as well as by bottom bubbling using the bottom gas blowing devices 34.
  • the maximum level M of the bath 18 as illustrated in FIGS.1 &2 is measured from the hearth bottom 38 and considered at quiescent i.e. non-agitated bath and corresponds either to the height of the bath 18 reached immediately before tapping in a tapped vessel or to the substantially constant bath level in a vessel equipped with skimmer (siphon type metal discharge).
  • skimmer siphon type metal discharge
  • the layer of slag 20 in an SR process occupies considerable volume and may typically attain a considerable thickness due to gas inclusions (causing "foaming"), e.g. in the order of 1 -2m or more.
  • the refractory lining 16 in the vessel 10 is dimensioned to define a capacity of at least twice the maximum volume of the bath 18 or more, e.g. three times the molten metal capacity.
  • the height H of the lateral refractory lining 16 as measured from the hearth bottom 38 is therefore 2-4m depending on the useful area and vessel size.
  • the shell 12 and refractory lining 16 may be configured to define a reaction space whose cross-section increases with height as seen in FIGS.1 &2.
  • slag layer 20 Another noteworthy characteristic of the slag layer 20 is due to the fact that at least part of, if not all (e.g. in case of an oxy-coal or hot blast-coal smelter) the heat required for SR reactions is provided by combustion (C + Vz O 2 -> CO) and (post-)combustion (CO + Vz O 2 -> CO 2 ). To this end carbon and oxygen are injected into the slag layer 20 using the lances 26 and 30 respectively. In an oxy-coal or hot blast-coal smelter for example, carbon is injected at a rate of typically 700-1300kg C/(h * m 2 ).
  • the slag layer 20 has a very high temperature and may be overheated (with respect to the melting point of the pig iron in the bath 18) by at least 100°C attaining temperatures of >1700 ⁇ € in the upper region of the layer 20. Also noteworthy, as regards chemical composition, is that the slag forming the layer 20 normally has comparatively high basicity/alkalinity.
  • the present invention proposes an installation and method for cooling the refractory lining 16 in the zone T, which in the presently proposed configuration were heretofore unknown.
  • the SR vessel 10 is equipped with copper slabs 40.
  • the major part of the cooling installation, i.e. of the copper slabs 40 is arranged above the level M so as to be in thermo-conductive contact with the refractory lining 16 in its most wear prone zone T.
  • the copper slabs 40 are arranged so that the range of action of the cooling system covers substantially the entire zone T.
  • an appropriate filling compound that is thermally stable and conductive such as graphite may be used for improving thermal conduction between the slabs 40 and the bricks 40 in the zone T.
  • each row 41 , 42 surrounds a respective partial zone of the refractory lining 16 in substantially continuous manner (except e.g. at the slag notch location), with the horizontal section of each slab 40 being appropriately chosen.
  • the copper slabs 40 in each row 41 , 42 are disposed to be generally parallel to the outer contour of the refractory lining 16, and thus may be vertical (row 42) or slightly slanted (row 41 ) as seen in FIG.1.
  • cooling limited to the zone of turbulence T will considerable limit wear of the refractory lining 16 even though little if any cooling (i.e. besides thermal conduction in vertical direction) of the refractory bricks 14 below the level M is provided.
  • each row 41 , 42 of copper slabs 40 has a number of associated rows of spray cooling devices 44. While their actual arrangement depends on the height of the copper slabs 40, two rows 45, 46 of spray cooling devices 44 are associated to each row 41 , 42 of copper slabs 40 respectively in the embodiment of FIG.1.
  • the number of spray cooling devices 44 of a given row that are associated to one particular slab 40 depends on the width of the slab 40 in question, with typically at least one spray cooling device 44 in each row 45, 46 being associated to each slab 40.
  • a separate and respective opening 48 e.g. in form of a cut-out, is provided in the shell 12 at least for each vertical set of slabs 40 or for each individual slab 40 respectively.
  • the refractory lining is actively cooled by virtue of thermal conduction using spray cooling devices 44 spraying liquid coolant 50 onto the outer side of the copper slabs 40 through the openings 48.
  • the copper slab rows 41 , 42 cover a vertical zone of the refractory lining that generally corresponds to the zone T, i.e. a zone that extends substantially from the minimum level of the bath of molten metal 18 (which in a tapped vessel may correspond to the level of hot metal immediately after tapping or, in a skimmed vessel to the constant bath level), to normally at least 1 m above the level M, and generally up to the upper edge of the refractory lining 16 as seen in FIG.1.
  • the rows 41 , 42 of copper slabs span a vertical range of about 1400- 1500mm.
  • the arrangement of copper slabs will span a vertical range of about 1 -2m, depending on the vessel size.
  • FIG.2 shows another type of SR vessel 1 10 for illustrating a second embodiment of the invention.
  • the SR vessel 1 10 of FIG.2 basically differs from the vessel 10 of FIG.1 in that the heat supply is a dual mode heat supply, namely an electric arc supported carbon combustion heat supply.
  • the SR vessel is equipped with three electrodes 1 1 1 , delivering a heating power that is approximately equal to the heating power developed by carbon combustion and thereby allows savings as regards the required amount of carbonaceous fuel.
  • carbonaceous material is fed into the vessel 1 10 together with the raw material feed 24 via the gravity feed charging chute 22, e.g. by adding excess coal to DRI originating from a hearth furnace.
  • the vessel 1 10 is equipped with combined primary and secondary oxygen injection lances 126 adapted to inject a hard blow 129 through the slag layer 20 into the bath 18 (usually at a pressure in the order of 5-10bar) and a soft blow 128 into the slag layer 20 only for heat supply by carbon combustion and post-combustion respectively.
  • the slag of the layer 20 also presents the aforementioned SR-typical characteristics during operation of the vessel 1 10, namely strong turbulence (due to hard blow oxygen injection from the lances 126 and bottom blowing by the devices 34), high temperature and chemical aggressiveness. Consequently, a cooling installation of the proposed type is provided for cooling the refractory lining 16 in the turbulence zone T of the slag layer 20.
  • the cooling installation comprises a single row 141 of copper slabs 140 of comparatively larger height for covering the zone T.
  • the row 141 of copper slabs 140 is arranged mainly above the level M as seen in FIG.2 and in circumferentially surrounding manner as seen in FIG.3, which schematically shows the circular horizontal projection of the vessel 1 10.
  • three rows of cooling devices 144 are associated to the single row 141 of copper slabs 140 for spraying liquid coolant 50 onto the outward face of the copper slabs 140 through corresponding openings 148 provided in the shell 12.
  • the spray cooling devices 144 are provided with a water collection casing 152 for draining liquid coolant 50.
  • FIG.3 schematically shows the curved copper slabs 140 having a circular arc shaped section so as to adapt to the horizontal projection of the vessel 1 10 and the lining 16 in particular.
  • the rear face only of the slabs can be machined to conform to the shape of the shell 12.
  • the copper slabs 140 are arranged to completely surround the lining 16.
  • One spray cooling device 144 in each row is associated to one copper slab 140, higher numbers being possible.
  • Arrows in FIG.3 further illustrate the impulses conferred to the slag layer 20 and thus contributing to strong turbulence of the latter.
  • FIG.3 also schematically illustrates the finding that a spray profile covering only a fraction (e.g.
  • the outer horizontal extent (in case of a circular vessel: a fraction of the radian measure of the outer face of the slab) of the copper slabs 140 is sufficient for efficient cooling, the high thermal conductivity of copper warranting a substantially uniform temperature distribution across the slabs 140.
  • the total number of spray cooling devices 144 can be reduced.
  • FIG.4 shows a specific embodiment of a copper slab 240 and spray cooling device 244 combination.
  • Material composition and shape of the copper slab 244 itself may substantially correspond to what has been described in international patent application no. PCT/EP2006/060337 with one possible difference being an increased height of the slab 244 in order to reduce the number of required rows for covering the entire zone T, the slabs having a height in the order of 500-800mm, preferably 600-750mm, for example.
  • Thickness of the slab 244 may be in the order of 20-80mm with 20mm as a minimum in case the slab has a non uniform thickness (e.g. for adapting to a circular vessel section as shown in FIG.3 without curving the entire slab).
  • FIG.4 further shows two spraying nozzles 260 arranged one above the other.
  • the nozzles 260 are preferably energy efficient hydraulic spray nozzles utilizing coolant pressure as energy source to break the coolant into droplets and thus eliminating the need for a pressurized gas supply as required for atomized spray nozzles. More preferably, the nozzles 260 are hydraulic spillback nozzles allowing adjustment of the coolant discharge rate without affecting droplet size and coolant pressure. Due to the cone angle of the spraying nozzles 260 (e.g. 80-120°) and the limited distance between the nozzle tip and the copper slab 240, a number of nozzles 260 is required to cover a substantial vertical range of the slab 240 with coolant.
  • the nozzles 260 are to be connected to a pressurized water supply and are conveniently mounted to a removable rear panel of a water collection casing 252 equipped with a drain 254 for draining used coolant. Except for the dimensions, other features of the casing 252 (e.g. the mount for a temperature sensor for measuring the temperature of the slab 240) correspond to what has been described in application PCT/EP2006/060337 and are therefore omitted here.
  • a selection of copper slabs 40, 140, 240 is made e.g. in accordance with the hottest regions of the temperature profile.
  • the selected slabs 40, 140, 240 are equipped with dedicated temperature sensors (not shown) in order to monitor slab temperatures.
  • each individual slab 40, 140, 240 can be equipped with a temperature sensor.
  • the temperature sensors are connected to a process control system (not shown), which is also connected to actuators such as valves and pumps for setting at least the flow rate and preferably also the temperature and fluid pressure of the coolant fed to the spray cooling devices 44, 144, 244.
  • operation of the spray cooling devices 44, 144, 244 may be controlled for each set associated to a particular slab individually, for a number of sets associated a number of slabs collectively or, most economically, for the sets of all slabs 40, 140, 240 in common.
  • Such low temperatures at the slabs 40, 140, 240 enable a further decrease of the temperature at the hot face of the refractory lining 16, which is in contact with the layer 20 of molten high temperature slag. Wear of the lining 16 is thereby further reduced.
  • Such low temperatures can be achieved among others by means of a sufficiently high and uninterrupted coolant flow rate (e.g. 1 -4m 3 /h) preferably complemented by sufficiently low coolant inlet temperature (well below the aimed slab temperature, e.g. «60 0 C) at each spray cooling device 44, 144, 244.
  • the control system may also be equipped with any other sensor arrangement suitable for detecting unwanted evaporation of the coolant.
  • the spray defining parameters of coolant flow rate and coolant pressure are preferably controlled to achieve a droplet size spectrum of the spray which is sufficiently large to avoid (rapid) evaporation on impacting onto the slabs the slabs 40, 140, 240 (e.g. a droplet spectrum > 200 ⁇ m), noting that too small a droplet size tends to result in evaporation even at slab temperatures below the evaporation point of the liquid coolant.
  • the liquid coolant stays in liquid aggregation state during the entire cooling cycle.
  • avoiding evaporation allows eliminating the need for an expensive vapour collection and condensation system typically required with known evaporation mode spray cooling systems.
  • the process control is configured to avoid formation of a continuous film of liquid coolant on the copper slabs 40, 140, 240, at least within the spray impact area. Substantially eliminating a continuous coolant film allows avoiding loss of cooling capacity due to transition film boiling (a small but heat isolating layer of vapour between the cooled surface and the continuous film).
  • the nozzles of the spray cooling devices 44, 144, 244 are placed at an appropriate distance from the copper slabs 40, 140, 240 and their operating parameters, i.e. flow rate and droplet size spectrum in particular, are set to values that allow formation of a plurality of small streamlets trickling from the spray impact zone downwards on the outer cooled face of the copper slabs 40, 140, 240 towards the drain.

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)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)

Abstract

L'invention porte sur le refroidissement du garnissage réfractaire d'un récipient de réduction par fusion pour produire du métal chaud. Le récipient comprend une enveloppe externe et un garnissage réfractaire interne pour contenir un bain de métal fondu et une couche de laitier au-dessus du bain. Pour créer une couche de laitier turbulente volumineuse afin d'améliorer le transfert de chaleur de post-combustion à l'intérieur de la couche de laitier, le récipient comprend en outre au moins l'un des dispositifs suivants : - un dispositif d'insufflation de gaz par le fond pour faire barboter le bain de métal fondu et la couche de laitier; - un dispositif d'injection pneumatique pour injecter une matière carbonée dans la couche de laitier; ou - un dispositif d'injection de gaz oxydant pour injecter un gaz oxydant dans la couche de laitier. Le garnissage réfractaire est dimensionné pour définir une capacité d'au moins deux fois le volume maximal du bain de métal fondu de façon à contenir la couche de laitier turbulente volumineuse. Une installation de refroidissement est disposée dans la zone de la couche de laitier turbulente, au moins une partie majeure de l'installation étant située au-dessus du niveau maximal du bain de métal fondu pour refroidir le garnissage réfractaire interne dans la zone de turbulence du laitier. Conformément à l'invention, l'installation de refroidissement comprend au moins une rangée de plaques de cuivre montées sur des ouvertures pratiquées dans l'enveloppe externe de façon à être en contact thermo-conducteur avec le garnissage réfractaire interne dans la zone de la couche de laitier turbulente et au moins une rangée de dispositifs de refroidissement par pulvérisation associée à la rangée de plaques de cuivre pour pulvériser un réfrigérant liquide sur les plaques de cuivre à travers les ouvertures pratiquées dans l'enveloppe.
PCT/EP2009/050150 2008-01-11 2009-01-08 Refroidissement d'un récipient de réduction par fusion métallurgique Ceased WO2009087183A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
LU91408A LU91408B1 (en) 2008-01-11 2008-01-11 Cooling of a metallurgical smelting reduction vessel
LU91408 2008-01-11

Publications (1)

Publication Number Publication Date
WO2009087183A1 true WO2009087183A1 (fr) 2009-07-16

Family

ID=39661401

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2009/050150 Ceased WO2009087183A1 (fr) 2008-01-11 2009-01-08 Refroidissement d'un récipient de réduction par fusion métallurgique

Country Status (4)

Country Link
CN (1) CN201201953Y (fr)
LU (1) LU91408B1 (fr)
TW (1) TW200932917A (fr)
WO (1) WO2009087183A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2673387A4 (fr) * 2011-02-09 2017-06-21 Technological Resources Pty Limited Procédé de fusion directe

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT202000000793A1 (it) * 2020-01-17 2021-07-17 Tenova Spa Procedimento ed impianto perfezionati per preriscaldare una carica metallica alimentata in continuo ad un forno fusorio elettrico

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0044512A1 (fr) * 1980-07-19 1982-01-27 Fuchs Systemtechnik GmbH Procédé et dispositif pour le refroidissement des parties de la cuve d'un four métallurgique, en particulier d'un four à arc électrique
US5561685A (en) * 1995-04-27 1996-10-01 Ucar Carbon Technology Corporation Modular spray cooled side-wall for electric arc furnaces
EP0735146A1 (fr) * 1995-03-29 1996-10-02 Hoogovens Staal B.V. Dispositif pour la fabrication de fonte par réduction directe
JPH09217990A (ja) * 1996-02-09 1997-08-19 Daido Steel Co Ltd 水冷式中空体における冷却状況検査方法
US5741349A (en) * 1995-10-19 1998-04-21 Steel Technology Corporation Refractory lining system for high wear area of high temperature reaction vessel
WO2000001854A1 (fr) * 1998-07-01 2000-01-13 Technological Resources Pty. Ltd. Cuve et procede de fusion directe
US20040194940A1 (en) * 2001-09-19 2004-10-07 Manasek Richard J. Heat exchanger system used in steel making
WO2006089971A2 (fr) * 2005-02-28 2006-08-31 Paul Wurth S.A. Four electrique a arc
WO2007134382A1 (fr) * 2006-05-18 2007-11-29 Technological Resources Pty. Limited Cuve de fusion directe et refroidisseur pour celle-ci

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5601427A (en) * 1994-07-25 1997-02-11 Daidotokushuko Kabushikikaisha Waste melting furnace and a method of melting wastes

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0044512A1 (fr) * 1980-07-19 1982-01-27 Fuchs Systemtechnik GmbH Procédé et dispositif pour le refroidissement des parties de la cuve d'un four métallurgique, en particulier d'un four à arc électrique
EP0735146A1 (fr) * 1995-03-29 1996-10-02 Hoogovens Staal B.V. Dispositif pour la fabrication de fonte par réduction directe
US5561685A (en) * 1995-04-27 1996-10-01 Ucar Carbon Technology Corporation Modular spray cooled side-wall for electric arc furnaces
US5741349A (en) * 1995-10-19 1998-04-21 Steel Technology Corporation Refractory lining system for high wear area of high temperature reaction vessel
JPH09217990A (ja) * 1996-02-09 1997-08-19 Daido Steel Co Ltd 水冷式中空体における冷却状況検査方法
WO2000001854A1 (fr) * 1998-07-01 2000-01-13 Technological Resources Pty. Ltd. Cuve et procede de fusion directe
US20040194940A1 (en) * 2001-09-19 2004-10-07 Manasek Richard J. Heat exchanger system used in steel making
WO2006089971A2 (fr) * 2005-02-28 2006-08-31 Paul Wurth S.A. Four electrique a arc
WO2007134382A1 (fr) * 2006-05-18 2007-11-29 Technological Resources Pty. Limited Cuve de fusion directe et refroidisseur pour celle-ci

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2673387A4 (fr) * 2011-02-09 2017-06-21 Technological Resources Pty Limited Procédé de fusion directe

Also Published As

Publication number Publication date
LU91408B1 (en) 2009-07-13
TW200932917A (en) 2009-08-01
CN201201953Y (zh) 2009-03-04

Similar Documents

Publication Publication Date Title
EP1067201B1 (fr) Procédure de démarrage pour un procédé de fusion directe
US6322745B1 (en) Direct smelting vessel and direct smelting process
KR100611692B1 (ko) 직접 제련 방법 및 장치
US7914601B2 (en) Cold start-up method for a direct smelting process
EP0735146B1 (fr) Dispositif pour la fabrication de fonte par réduction directe
EP1114191A1 (fr) Procede de fusion directe
EP3077552B1 (fr) Procédé et appareil de fusion
JP2001289571A (ja) 容器の裏張りを張替える方法
EP2877606B1 (fr) Initiation d'un procédé de fusion
US11391515B2 (en) Convertible metallurgical furnace and modular metallurgical plant comprising said furnace for conducting production processes for the production of metals in the molten state, in particular steel or cast iron
EP3237131B1 (fr) Procédé d'obturation et de réparation d'un trou de coulée réfractaire
WO2009087183A1 (fr) Refroidissement d'un récipient de réduction par fusion métallurgique
AU2004201935B2 (en) Metallurgical reactor for the production of cast iron
US20230407422A1 (en) Direct bath smelting process with management of peripheral cold zones at the metal-slag interface
EP1431403A1 (fr) Dispositif et procédé de fusion directe
RU2342442C2 (ru) Установка для получения расплава железа
Argenta et al. Hot metal charging to an EAF at Shaoguan using Consteel®

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: 09701297

Country of ref document: EP

Kind code of ref document: A1

DPE1 Request for preliminary examination filed after expiration of 19th month from priority date (pct application filed from 20040101)
NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09701297

Country of ref document: EP

Kind code of ref document: A1