CN201512549U - Device for melting sponge iron by heating, separating iron slag and refining molten steel - Google Patents

Abstract

The utility model relates to a device for melting sponge iron by heating, separating iron slag and refining molten steel in the metallurgical field. A slag notch and a slag trough are formed on the upper side wall of a melting-separation furnace; a furnace cover and a lifting system thereof are arranged on the upper part of the melting-separation furnace; a slide gate nozzle and a blowing nozzle are formed at the bottom of the melting-separation furnace; the blowing nozzle is connected with a protective air blowing system; a pressure sensor is arranged on the air inlet of the air blowing system; a feeding system is arranged on one side above the melting-separation furnace; a three-phase electrode automatic adjusting system and a power supply system are arranged on the other side above the melting-separation furnace; a micro-positive pressure control, air-drafting and dust-removing system is arranged above the melting-separation furnace; and the melting-separation furnace is arranged on a movable furnace car system. The device for melting sponge iron by three-phase arc heating, separating iron slag and refining molten steel can smelt high-quality steel or special steel from the pure sponge iron.

Description

The heat fused of sponge iron and slag iron separate and the liquid steel refining device

Technical field

Three-phase electric arc heat fused and slag iron that the utility model relates to metallurgy industry steelmaking equipment, particularly a kind of sponge iron separate and the liquid steel refining device.

Background technology

Sponge iron, also claim direct-reduced iron, be called for short DRI (Direct Reduction Iron), be to use the low ferric oxide of foreign matter contents such as higher-grade iron ore, pellet or iron scale at the solid-state metallurgic product of directly going back original production, can be used as the surrogate of steel scrap, being one of the important means of dilution harmful element with addition of DRI in the steel-making, also be to improve the important source material that steel product quality increases kind, so it becomes the selection that countries in the world possess the area development Iron And Steel Industry of resources supplIes.According to U.S.'s Mead rex corporate statistics, world's DRI output reached 6,722 ten thousand t in 2007, and development rapidly.China also builds up the tunnel furnace production line of many DRI in succession, and output improves year by year.

But containing 10% the impurity of having an appointment among the DRI (mainly is SiO ₂), it originally was exactly to be blended in the powdered iron ore, can not remove when solid state reduction, so DRI uses it for anything else except the surrogate of making steel scrap less.Fusing and the slag iron that solves DRI separates (being called for short molten the branch) and is smelt qualified steel, becomes current scientific research task.

The molten branch of DRI has following several method at present, but all has certain shortcoming:

1, electric arc furnace is molten divides.In electric furnace arrangement for producing steel, add steel scrap in advance and make raw material, be melted to certain molten steel, again the DRI briquetting is added melting.The DRI quality is loose, and volume density is slightly larger than 1.6t/m ³, briquetting also has only 3t/m ³-4t/m ³(steel is 7.8t/m ³), very easily oxidation under the effect of high temperature air in electric arc furnace, production practice show that the recovery rate of iron is lower, and power consumption is higher, and production cost is higher.Secondly the equipment complexity of electric arc furnace continuous charging is invested greatly, and the following electric furnace of capacity 30t is difficult to adopt.

2, medium-frequency induction furnace is molten divides.DRI is to the weak effect of induction heating, and research trial shows must have 30% left and right sides molten steel could add the DRI briquetting continuously in the stove; Slag induction heating is poorer, stove middle part temperature height, problem that head temperature is low can occur, and is difficult for the person of being operated and realizes, thereby causes security incident.The low problem of oxidation and recovery rate is equally also arranged.So method is not promoted.

3, cupola melting.DRI mixing metallurgical coke joins fusing in the cupola furnace, the similar blast furnace ironmaking of this method.Research experiment shows that C content increases because of the molten iron tapping temperature is low, is difficult to enter down smelting procedure one, so no using value.

4, the molten branch in the converter, make the additional material of converter steelmaking.The DRI briquetting is widely used as the additional cold burden that molten steel temperature is regulated in converter steelmaking at present.Because the molten steel of a large amount of other compositions exists, so method can not obtain highly purified molten steel.

The utility model content

The purpose of this utility model is to provide a kind of three-phase electric arc heat fused and slag iron simple in structure, easy to operate, DRI that level of automation is higher to separate and the liquid steel refining device, thereby is implemented in the ultrashort flow process purpose of smelting high-quality steel or special steel with DRI completely.

The purpose of this utility model is achieved in that

Consult Fig. 1 and Fig. 2 (only convenient understanding, structure can not limit protection domain of the present utility model among the figure), the upper side wall of molten minute of the present utility model stove is provided with slag notch 40 and ash shoot 39 thereof, and the molten top of stove of dividing is provided with bell 25 and lifting system thereof; The molten bottom of stove of dividing is provided with slide gate nozzle 55 and puff port 44, and puff port 44 is connected with shielding gas and is blown into system, and the inlet pipe that gas is blown into system is provided with pressure transmitter 47; Molten top one side of stove of dividing is provided with blanking system, and opposite side is provided with three-phase electrode varitrol and power supply system, and the setter 69 in the electrode regulating system connects microcomputer PLC treatment system; The molten stove top of dividing also is provided with pressure-fired control and ventilation and dust removal system; Molten ash shoot 39 downsides of stove that divide are provided with out slag ladle and transport system; The molten stove that divides is located at movably on the table truck system.

The skin of above-mentioned molten minute furnace body is an outer cover of steel plate 24, and the middle level is a stamp mass 37, the working lining 38. of internal layer for being built by laying bricks or stones by magnesia carbon brick

Above-mentioned blanking system is made of tremie pipe 17 and hopper 18, and its tremie pipe 17 is vertically corresponding to three electrodes, the 16 distribution circle centers of circle.

Current transformer 67 in the above-mentioned three-phase electrode varitrol connects reometer 68, reometer 68 connects the automatic electrode regulator 69 that has microcomputer PLC treatment system, setter 69 is connected with electrode dolly 6 by electric motor 1, gear 2, step-down gear 3, output gear 4, tooth bar 5 successively, electrode dolly 6 can move up and down along column 11,15, three electrode 16 holdings of electrode dolly 6 connection electrode dops are in dop 15 and be scattered in that equilateral triangle is vertical to be inserted molten the branch in the stove 24.

Four wheels is arranged at table car 19 bottoms in the above-mentioned movably table truck system, and wheel has rail 35; Table car 19 is provided with body of heater carriage 21, and its end links to each other with table car 19 through rotating shaft 20, and the other end is provided with electric motor spiral furnace tilting mechanism 22, and the horizontal direction of body of heater carriage 21 is provided with electronic binding clasp 23.Carriage 21 is under the state that clamps, and the molten stove that divides can tilt 10 ° with interior angle.

Flue dust collecting cover 29 in above-mentioned pressure-fired control and the ventilation and dust removal system places bell 25 tops to link to each other with Smoking pipe 30, Smoking pipe 30 links to each other with induced draft fan 31, induced draft fan 31 links to each other with electric motor 72, and electric motor 72 links to each other with variable frequency regulating speed control cabinet 71, and housing 71 links to each other with self-operated regulator 69.

Slide gate nozzle 55 in above-mentioned molten minute stove and the slide gate nozzle brick cup 57 in the puff port 44 and gas permeable brick brick cup 43 are separately positioned on the angular bisector of two electrode holes, dress is irritated drainage sand 56 in the slide gate nozzle 55, be provided with pull lever 54 outside the mouth of a river, the puff port 44 outer gas permeable brick brick cups 43 that are provided with.

The inlet pipe that above-mentioned gas is blown into system links to each other with flexible pipe 46 by rapid-acting coupling 45, and the inlet end of inlet pipe is provided with gas switching valve 49, and this switching valve links to each other with argon gas gas holder 53 with nitrogen gas holder 52 with argon gas valve 51 by nitrogen valve 50 respectively.

The high-voltage power supply of the 6KV-10KV bus 62 in the above-mentioned power supply system is connected furnace transformer 65 through isolator 63 with vacuum switch 64, and furnace transformer is connected to Graphite Electrodes 16 through conducting copper 66, water-cooled bunched cable 7, contact tube 8, electrode dop 15.

Bell 25 in above-mentioned bell and the lifting system thereof is made by two-layered steel plates, middle water flowing cooling, internal layer weldering hook nail is filled out stamp mass, a fire door 27 is established on the bell inclined-plane, bell top board 28 is established three electrode holes and a blanking hole that is in the center of circle by the mould material knotting on the top board 28, top board 28 is placed on above the bell 25, the bell shell is established chain 26 suspentions of four arms by the bell lifting system, and its transmission system is made up of electric motor-stopper-step-down gear-wireline-pulley and chain wheel set.

Before the utility model work, its molten DRI briquetting 41 and slag charge 42 that divides stove to pack into an amount of by the requirement of Fig. 2, then by the overhead traveling crane handling to table car 19, the table car reaches the heating station of three-phase electrode 16 bottoms along rail 35, covers bell 25.Its power supply system such as Fig. 5 send; electrode 16 inserts molten the branch in the stove 24, contacts with DRI briquetting 41 and produces electric arc 61, heat fused DRI briquetting 41 and slag charge 42; open valve 50 (or 51), switching valve 49 and pressure regulator valve 48 simultaneously, be blown into shielding gas 60 to molten the branch in the stove 24.The tremie pipe 17 of blanking system and hopper 18 constantly add DRI briquetting 41, on one side reinforced, fusing on one side, the electrode regulating system adjusts the height location of electrode 16 in good time, keeps electric arc 61 stable burnings.When DRI molten steel 58 rises to molten minute stove slag notch 40, disclose and leave cinder notch filler eliminating slag 59, the molten phase out of DRI.Add new slag charge by tremie pipe 17 and hopper 18 then, stir with blowing Ar, the molten molten steel in the stove 58 that divides changes refining stage over to: decon, the degassing, heat up, take off S, adding alloy, obtain required steel grade after the refining in tens of minutes.Refining finishes, and promotes electrode 16 and bell 25, and table car 19 is left along rail 35, and overhead traveling crane will melt branch stove 24 integral body and hang next station.

Advantage of the present utility model is that complete assembly is simple in structure, makes easily, and easy to operate, level of automation is higher, and the production operation technology of being drafted is clear and definite, and is reliable, easy to maintenance.Its main raw material DRI is fine quality, contains harmful elementary sulfur S, phosphorus P, arsenic As, tin Sn, antimony Sb, plumbous Pb and bismuth Bi and all lacks.Because the utility model is only used DRI, does not use other steel scraps with, has guaranteed the pure property of molten steel, has created condition for smelting various special steels; Because the molten whole process of dividing of DRI has gas shield, makes the recovery rate height of iron, consumes low; Because dreg removing system is arranged, make DRI after molten the branch, can enter the refining procedure of molten steel smoothly, flow process is short, and production cost is low; Because the molten stove that divides can be accomplished the operation in turn of many covers, is convenient to mobile handling again, is connected with subsequent handling (vacuum-treat, ingot casting, continuous casting), allows the utility model that use occasion is widely arranged.China's crude steel production capacity surplus, but special steel scarce capacity, national import steel 1542.8 ten thousand t in 2008,1-6 month import steel 8,130,000 t in 2009 mainly are the special steel classes.The utility model provides new way for satisfying domestic and international demand production special steel.

Description of drawings

Fig. 1 is an one-piece construction synoptic diagram of the present utility model.

Fig. 2 is molten basic structure and the initial smelting synoptic diagram that divides stove among Fig. 1.

Fig. 3 is the molten normal smelting synoptic diagram that divides stove among Fig. 1.

Fig. 4 is the molten relative dimensions synoptic diagram that divides stove among Fig. 1.

Fig. 5 is power supply and electrode automatic principle of compensation synoptic diagram.

Fig. 6 is molten pressure-fired control and the ventilation and dust removal synoptic diagram that divides stove.

Fig. 7 is power supply and electrode automatic principle of compensation skeleton diagram.

Embodiment

The disclosed structure of above accompanying drawing is the structure of an embodiment of the utility model.Among the figure, parts 1-16 constitutes the electrode automatic lifting system, and 17-18 constitutes charging system, and 19-23 constitutes the table truck system, 24 are the molten stove (being shell wherein in fact) that divides, 25-28 constitutes bell and lifting system thereof, and 29-31 constitutes the ventilation and dust removal system, and 32-36 constitutes slag ladle and transport system, 37-44 and 54-57 constitute the molten refining furnace integral body of dividing, 45-53 constitutes scavenger system, and 58-61 is a material in the smelting furnace, and 62-72 constitutes power supply and regulation system.

The utility model is by forming with the lower section: three-phase electric arc heating power supply system (), rise fall of electrodes system (two), charging system (three), table truck system (four), moltenly divide furnace body and scavenger system (five), bell and lifting system (six) thereof, a ventilation and dust removal system (seven), go out slag ladle and transport system (eight).

Described three-phase electric arc heating power supply system (one) as shown in Figure 5.The high-voltage power supply of 6KV-10KV bus 62 is powered to furnace transformer 65 through isolator 63 and vacuum switch 64, furnace transformer possesses the on-load voltage regulation function, can satisfy the molten requirement of stove that divide in each smelting required different voltage ranges in period, the three-phase low-voltage power supply of appropriate numerical value arrives Graphite Electrodes 16 through conducting copper 66, water-cooled bunched cable 7, contact tube 8, electrode dop 15, three electrodes are insulated from each other, be scattered in equilateral triangle and insert molten the branch in the stove 24, produce arc light 61 heating and melting batch between electrode and the furnace charge.

Described rise fall of electrodes system (two) is as Fig. 1, Fig. 5 and shown in Figure 7.The size of heating power is detected by current transformer 67, and reometer 68 is shown to the operator, and the microcomputer PLC treatment system that current signal enters automatic electrode regulator 69 is smelted in this heating; The actual voltage signal of smelting of heating also enters the PLC system.When reality heating is smelted the given electric current of electric current and operator when close, the PLC no-output, frequency transformer is no-output also, and electric motor 1 is not charged, gear 2, step-down gear 3, output gear 4, tooth bar 5, electrode dolly 6 all remain static, this device keep given electric current continue heating.When heating smelting electric current was less than normal, PLC and frequency transformer can be exported the power supply of decline phase sequence, and electric motor 1 is to the descending direction rotation, and electrode dolly 6 is driven by tooth bar 5 and moves down along column 11 tracks, electric arc 61 contraction in lengths, and electric current is strengthened, up to set-point.The electrode lowering speed is relevant with the size of current deviation.Can not the starting the arc burn if nonconducting furnace charge has been withstood in electrode decline, the PLC system of setter 69 can detect, and blocks to descend, and guard electrode 16 is not broken by plug.In like manner, when heating smelting electric current was bigger than normal, PLC and frequency transformer can be exported the power supply of rising phase sequence, finally promote electrode, elongate electric arc, and electric current is reduced, and returns to the set-point operation.

Electrode dolly 6 is connected with counter weight 14 by tackleblock 12 by wireline 13, the total mass of its rising and decline different directions is near balance, the rise fall of electrodes light and flexible, has quick tracking performance, can be when reinforced, air blowing cause the molten steel liquid fluctuating, string is not moving up and down to guarantee electrode, does not contact molten steel and increases C, and arc light does not expose top of the slag scaling loss furnace lining.

When electrode erosion needs spreading, unclamp electrode by pressurized air (or hydraulic pressure) and clamp cylinder (or oil cylinder) 9, pull bar 10 is lax, and electrode 16 prolongs to lower slip, and then clamps.

Described charging system (three) as shown in Figure 1.Tremie pipe 17 must be arranged vertically over against the distribution circle center of circle of three electrodes, guarantees that furnace charge vertically falls the molten three-phase electricity camber warm area that divides stove, hopper, weighs and belt conveyor system 18 manufactures and designs routinely.

Described table truck system (four) as shown in Figure 1.Table car 19 is supported by four wheels, is motion-work wheel near the electrode lifting device side, is follow-up pulley near slag car 34 sides, electric motor-stopper-step-down gear transmission system is arranged, in the translational speed 10m/min on the table car.Establish body of heater carriage 21 on the table car, its end links to each other with table car 19 through rotating shaft 20, and the other end is provided with electric motor spiral furnace tilting mechanism 22.The horizontal direction of body of heater carriage is equipped with electronic binding clasp 23.The table truck system can deliver the molten stove turnover heating station that divides, and under the state that clamps, the molten stove that divides can tilt 10 ° with interior angle.

Described molten minute furnace body and scavenger system (five) are as Fig. 2, shown in Figure 3.The housing of cylindrical molten minute stove 24 is made with the steel plate of thick 16mm-20mm, and internal layer is a stamp mass 37, and about thick 120mm, working lining 38 is built by laying bricks or stones by magnesia carbon brick, and thickness is no less than 200mm; Furnace bottom is built by laying bricks or stones with high alumina brick, sets up slide gate nozzle 55 and puff port 44 separately, and slide gate nozzle brick cup 57 and gas permeable brick brick cup 43 are arranged in by Fig. 4 on the angular bisector of two electrode holes, and its center of circle is far from about the 200mm of furnace wall.Dress is irritated drainage sand 56 in the slide gate nozzle, and pull lever 54 when putting molten steel, at first get rid of drainage sand, and molten steel also flows out.In the ventilative brick cup gas permeable brick 44 is arranged, its inlet pipe links to each other with flexible pipe 46 with rapid-acting coupling 45, pressure transmitter 47 is contained on the inlet pipe, pressure regulator valve 48 is installed in automatic electrode regulator operator's console 69 places, grasp the blow gas pressure size by the operator, gas switching valve 49 is by two-way source of the gas air feed, and one the tunnel through valve 50 and nitrogen N ₂Gas holder 52 communicates, and another road is through valve 51 and argon Ar ₂Gas holder 53 communicates.

Divide stove 24 bodies of heater high h molten ₂The place set out cinder notch 40 and ash shoot 39, builds by laying bricks or stones with refractory brick in the groove, slag notch is by the refractory mortar shutoff during normal smelting.Slag notch is to the molten height h that divides the furnace roof mouth ₁Get 600mm-700mm, if next process is vacuum-treat, h ₁Also to increase about 200mm.

The molten basic parameter and the size (see figure 4) of stove of dividing of DRI with practicality and economy meets the following table requirement

Illustrate:

(1). commercially available Graphite Electrodes diameter D ₁Produce by standard specifications, listed relative dimensions in the table.

(2). three-phase electrode distribution circle diameter D ₂Determine method: as far as possible little under the condition that can arrange tremie pipe 17, so that form the high-temperature zone that electric arc is concentrated.

(3). the anti-material inside diameter D of furnace bottom ₃Determine method: the first, furnace lining and arc light can not be too near, and second, to fill behind the molten steel weld pool surface long-pending minimum, reduces heat lost by radiation.

Described bell and lifting system thereof (six) are as shown in Figure 1.Bell 25 is made by two-layered steel plates, middle water flowing cooling, and internal layer weldering hook nail is filled out stamp mass, reduces the molten stove calorific loss that divides.A fire door 27 is established on the bell inclined-plane, makes thermometric, replenishes reinforced, observation usefulness.Bell top board 28 has four holes i.e. three electrode holes and the blanking hole in the center of circle by the mould material knotting, and top board 28 is placed on above the bell 25, plays semiclosed molten minute stove.The bell shell has chain 26 suspentions of four arms by the bell lifting system, and its transmission system is made up of electric motor-stopper-step-down gear-wireline-pulley and chain wheel set.

Described ventilation and dust removal systems (seven) are as Fig. 1 and shown in Figure 6.Flue dust collecting cover 29 places bell 25 tops, absorbs the flue dust of discharging from electrode hole, and it can the lifting with the lifting of bell.Smoking pipe 30 links to each other with induced draft fan 31, and induced draft fan electric motor 72 is by 71 controls of variable frequency regulating speed control cabinet, and motor speed is fast more, and the air inducing amount is big more.Motor speed is by operator's monitoring at automatic electrode regulator operator's console 69 places.The flue dust of sucking-off enters the bag-type dust removal system in workshop through piping.

Describedly go out slag ladle and transport system (eight) as shown in Figure 1.Slag ladle 33 is placed on the slag car 34, and slag trough 32 upper ends are over against the molten ash shoot 39 that divides stove 24, and the lower end is over against slag ladle 33.When needs connect slag, slag car 34 reached on the public chassis 36, vertically start chassis 36 again, connected with 35 pairs of rail, and slag car 34 laterally reach the molten stove station of slagging tap that divides and connect slag then.Slag car 34 and public chassis 36 all have transmission system separately, comprise electric motor-stopper-step-down gear-wheel.The molten branch of DRI and refining are come out of the stove the cycle at 3.5 hours/stove-4 hour/stove, and many molten slag car and the public chassis of stoves of dividing are shared.

Described production craft step is as follows:

1, the preparatory stage

Before molten branch stove 24 entered heating station, dress was irritated drainage sand 56 in slide gate nozzle 55, at hearth electrode distribution circle D ₁+ D ₂The triangular space put into conductive carbon blocks 41 (if the molten refining ultra low-carbon steel that divides is used the DRI briquetting), fill up slag charge 42 all around, the slag charge proportioning is that CaO accounts for about 95% CaF ₂Account for about 5%.Table car 19 reaches heating station then, covers bell 25.

2, the slag stage

Transformer 65 gears are selected the secondary line voltage that is not higher than 90V for use, high voltage isolator 63 and vacuum switch 64 close a floodgate, high-voltage power supply 62 is delivered on the electrode 16 after reducing voltage, automatic electrode regulator converts automatic operation to, so three-phase electrode 16 inserts molten the branch in the stove 24 from electrode hole, just produce arc light and begin slag when touching carbon piece or DRI briquetting 41.Smelt given electric current and progressively be adjusted to 100% rated current by 10% transformer rated current.The slag total amount adds in the stove gradually by about 10% preparations of tap, and enough slag protection furnace linings are by the arc light radiation, and absorb the heat of arc light, guarantee the high alkalinity of molten branchs whole process slag simultaneously, during the high alkalinity slag helps and the interior acid SiO of DRI ₂, the protection basic lining.

3, DRI is molten stage by stage

When the slag charge temperature of fusion reaches 1550 ℃-1600 ℃, begin to add the DRI briquetting from tremie pipe 17.About 1537 ℃ of pure iron fusing point, the fusing point of DRI is low slightly, fusing fully under 1550 ℃-1600 ℃ condition, the great (7.0t/m of ratio of molten steel ³) sink to bottom, molten bath, the little (2.5t/m of the proportion of slag liquid ³) float to top, molten bath, thus realize that slag iron separates fully.

The feed rate of DRI briquetting and burn-off rate will keep balance, and reinforced too fast meeting causes cold burden to pile up, and destroys the working of a furnace; Fed in raw material and to bring slag temperature too high damage furnace wall slowly or make molten steel increase harmful element P.Feed rate is estimated by following formula:

$\begin{array}{cc}\sqrt{3}\·V\·I\·\cos \mathrm{\φ}/600\×1000/60& \mathrm{Kg}/\min \end{array}$

In the formula: V-smelts line voltage V, can get transformer gear voltage

I-smelts electric current KA, when using high performance automatic electrode regulator, is given electric current

Cos φ-power factor gets 0.85

Along with molten carrying out of dividing, as early as possible voltage is brought up to the transformer rated value.

Establish tremie pipe 17 by described position, assurance DRI briquetting vertically falls into the three-phase electrode central section, briquetting proportion 3t/m from several meters height ³-4t/m ³, the about 2.5t/m of slag proportion ³, molten steel proportion 7.0t/m ³, mainly being distributed in the three-phase arc zone of molten steel 58 top slags 59 inside according to mechanics principle DRI briquetting, the arc light temperature is up to 5000 ℃, so the DRI briquetting is melted rapidly.

Blow and protect: be blown into shielding gas when adding the DRI briquettings, allow whole molten minute stove 24 inside be full of shielding gas, prevent the DRI high temperature oxidation with tremie pipe 17.Shielding gas has N ₂And Ar ₂, common steel grade blows N ₂, special steel grade blows Ar ₂Open variable valve 48, pressure transmitter 47 detects blow gas pressure, is shown to the operator by digital watch 70.Blow gas pressure must appropriateness, and its appropriate standard is " fully stir and do not blow break layer ".Stove 24 belonged to semi-closed state in described molten minute, particularly melting liquid level in early stage is low, the operator can't observe the situation of the appropriateness of blowing, when the PLC-frequency conversion type automatic electrode regulator that adopts Wuhan magnificent power-saving technology development corporation, Ltd. to produce, the operator can judge the size of air-blowing quantity according to the throw of the pointer of smelting reometer 68: be that positive and negative about 1/10 of transformer rated current is appropriate with the amplitude of oscillation, if throw of the pointer is excessive, show that air-blowing quantity is excessive, liquation washes away easily and damages furnace lining, slag steel reinforced concrete volume, power consumption increase; If throw of the pointer is too small, show that air-blowing quantity is too small, be unfavorable for that molten steel stirs molten the branch, the too high damage furnace lining of slag temperature also can occur.In molten branch process,, liquid level to transfer big blow gas pressure gradually along with raising.

Keep pressure-fired atmosphere in the stove: in order to stop the molten stove that divides of air admission, further protect DRI not oxidized, must work under slight positive pressure state molten the branch in the stove.Bell outside flue dust collecting cover 29 links to each other with Smoking pipe 30, by induced draft fan 31 flue dust is extracted into fly-ash separator, induced draft fan electric motor 72 is by 71 controls of variable frequency regulating speed control cabinet, the operator determines the rotating speed of electric motor according to the size judgement pressure-fired degree that sprays flare around the bell, thereby regulates and control the size of rate of air sucked in required.

4, deslagging changes the slag stage

The interior quantity of slag of stove can reach about 20% of molten steel quality when molten branch finished, and it comes from three aspects: the impurity that slag in advance, DRI briquetting include and the furnace lining of scorification must enter next procedure by deslagging again.

Assign to the molten steel liquid level and reach slag notch 40 height h when DRI is molten ₂The time, stop reinforced and air blowing, slag car 34 reach and connect the slag position, disclose out the molten filler that divides the stove slag notch, and slag enters slag ladle 33 through ash shoot 39 and slag trough 32.The spontaneous current slag finishes back exhaust slag: promotes bell and electrode, moltenly divides that recrement can be under the situation that binding clasp 23 clamps in the stove, and starting furnace tilting mechanism 22, body of heater carriage 21 rotates around rotating shaft 20, makes in 10 ° of the tilting furnaces, has arranged recrement.Notice that deslagging should carry out at 1550 ℃-1570 ℃, to reduce the content of P in the molten steel.

Arranged the molten stove homing of dividing of slag, covered bell, added the required slag charge of liquid steel refining by tremie pipe 17, prescription determines that by steel grade (conventional ingredient has CaO, Al ₂O ₃, CaF ₂, CaC etc.), the quantity of slag: the 1.5%-2% that presses the molten steel quality.

5, the liquid steel refining stage

High tension transmission, transformer uses higher gear voltage.By the operation of common ladle refining furnace operating procedure, finish decon, the degassing, heat up, take off S, work such as molten steel alloying constituent adjustment.

With send electricity simultaneously with nitrogen N ₂Valve 50 cuts out, and opens argon Ar ₂Valve 51, the molten stove that divides is changed to and blows Ar by blowing N, and the size of air-blowing quantity is as previously mentioned.

Because C content is low among the DRI, molten branch low temperature deslagging in early stage removes P, and refining later stage high temperature takes off S, so it is low that the utility model can obtain C content, the pure molten steel that harmful element P, S, As, Sn, Sb, Pb and Bi are few has been created prerequisite for smelting various special steels, comprises low C and ultralow C steel.

6, tapping

Molten divide molten steel in the stove to reach that composition is qualified, the qualified also refining of temperature finishes, promote electrode and bell, unclamp binding clasp, the table car is opened from heating station, overhead traveling crane will melt the branch stove and hang ingot casting station ingot casting, perhaps arrive continuous casting station continuous casting, perhaps handle to vacuum oven.Special steel can be cast round base or square billet with horizontal caster.

If unspecified content is arranged, should be the known technology that maybe should know of those skilled in the art in more than narrating, do not repeat them here.

Claims (10)

1. the heat fused of a sponge iron and slag iron separate and the liquid steel refining device, and it is characterized in that: the upper side wall of its molten minute stove is provided with slag notch (40) and ash shoot (39) thereof, and the molten top of stove of dividing is provided with bell (25) and lifting system thereof; The molten bottom of stove of dividing is provided with slide gate nozzle (55) and puff port (44), and puff port (44) is connected with shielding gas and is blown into system, and the inlet pipe that gas is blown into system is provided with pressure transmitter (47); Molten top one side of stove of dividing is provided with blanking system, and opposite side is provided with three-phase electrode varitrol and power supply system, and the setter in the electrode regulating system (69) connects microcomputer PLC treatment system; The molten stove top of dividing also is provided with pressure-fired control and ventilation and dust removal system; Molten ash shoot (39) downside of stove that divides is provided with out slag ladle and transports system; The molten stove that divides is located at movably on the table truck system.

2. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: the skin of above-mentioned molten minute furnace body is outer cover of steel plate (24), the middle level is stamp mass (37), the working lining (38) of internal layer for being built by laying bricks or stones by magnesia carbon brick.

3. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: above-mentioned blanking system is made of tremie pipe (17) and hopper (18), and its tremie pipe (17) is vertically corresponding to three electrodes (16) distribution circle center of circle.

4. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: the current transformer (67) in the above-mentioned three-phase electrode varitrol connects reometer (68), reometer (68) connects the automatic electrode regulator (69) that has microcomputer PLC treatment system, setter (69) is successively by electric motor (1), gear (2), step-down gear (3), output gear (4), tooth bar (5) is connected with electrode dolly (6), electrode dolly (6) can move up and down along column (11), electrode dolly (6) connection electrode dop (15), three electrodes (16) holding are in dop (15) and be scattered in that equilateral triangle is vertical to be inserted molten the branch in the stove.

5. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: table car (19) bottom in the above-mentioned movably table truck system has four wheels, wheel to have rail (35); Table car (19) is provided with body of heater carriage (21), and its end links to each other with table car (19) through rotating shaft (20), and the other end is provided with electric motor spiral furnace tilting mechanism (22), and the horizontal direction of body of heater carriage (21) is provided with electronic binding clasp (23); Carriage (21) is under the state that clamps, and the molten stove that divides can tilt 10 ° with interior angle.

6. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: the flue dust collecting cover (29) in above-mentioned pressure-fired control and the ventilation and dust removal system places bell (25) top to link to each other with Smoking pipe (30), Smoking pipe (30) links to each other with induced draft fan (31), induced draft fan (31) links to each other with electric motor (72), electric motor (72) links to each other with variable frequency regulating speed control cabinet (71), and housing (71) links to each other with self-operated regulator (69).

7. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: slide gate nozzle (55) in above-mentioned molten minute stove and the slide gate nozzle brick cup (57) in the puff port (44) and gas permeable brick brick cup (43) are separately positioned on the angular bisector of two electrode holes, dress is irritated drainage sand (56) in the slide gate nozzle (55), be provided with pull lever (54) outside the mouth of a river, the outer gas permeable brick brick cup (43) that is provided with of puff port (44).

8. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: the inlet pipe that above-mentioned gas is blown into system links to each other with flexible pipe (46) by rapid-acting coupling (45), the inlet end of inlet pipe is provided with gas switching valve (49), and this switching valve links to each other with argon gas gas holder (53) with nitrogen gas holder (52) with argon gas valve (51) by nitrogen valve (50) respectively.

9. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: the high-voltage power supply of the 6KV-10KV bus (62) in the above-mentioned power supply system is connected furnace transformer (65) through isolator (63) with vacuum switch (64), and furnace transformer is connected to Graphite Electrodes (16) through conducting copper (66), water-cooled bunched cable (7), contact tube (8), electrode dop (15).

10. the heat fused of sponge iron according to claim 1 and slag iron separate and the liquid steel refining device, it is characterized in that: the bell (25) in above-mentioned bell (25) and the lifting system thereof is made by two-layered steel plates, middle water flowing cooling, internal layer weldering hook nail is filled out stamp mass, a fire door (27) is established on the bell inclined-plane, bell top board (28) is tied a knot by mould material, establish three electrode holes and a blanking hole that is in the center of circle on the top board (28), top board (28) is located at above the bell 25, the bell shell is established chain (26) suspention of four arms by the bell lifting system, and its transmission system is made up of electric motor-stopper-step-down gear-wireline-pulley and chain wheel set.

Images