HRP921268A2

HRP921268A2 - A process for continuous steelmaking

Info

Publication number: HRP921268A2
Authority: HR
Inventors: John Alexander Vallomy
Original assignee: Intersteel Technology Inc
Priority date: 1984-08-02
Filing date: 1992-11-16
Publication date: 1995-08-31
Also published as: HRP921268B1; BA97143B1

Description

Oblast tehnike The field of technology

Izum spada u oblast kontinuiranog topljenja metalne šarže u obliku proizvoda od istopljenog čelika. The invention belongs to the field of continuous melting of a metal batch in the form of a molten steel product.

Tehnički problem Technical problem

Postupak je naročito koristan u onim oblastima u kojima postoji koncentracija proizvodnje, ili se lako dobivaju otpaci i/ili direktno reducirano željezo (DRG), ili je električna energija i raspoloživa i ekonomična. The process is particularly useful in those areas where there is a concentration of production, or scrap and/or directly reduced iron (DRG) is easily obtained, or electricity is both available and economical.

Stanje tehnike State of the art

Do sada je rad peći za proizvodnju čelika pomoću električnog luka bila operacija sa prekidima, pri čemu se radilo po slijedećem redoslijedu: ubacivanje čeličnih otpadaka i/ili direktno reduciranog željeza, sirovog željeza, materije koje grade zguru i elemenata za legiranje; paljenje ili uspostavljanje električnog luka između elektroda u peći radi stvaranja uvjeta za topljenje šarže i za formiranje kupaone od istopljenog metala pokrivenog istopljenom zgurom; rafiniranja za vremenski period u toku kojega se dio istopljenog metala u kupaoni rafinira tako da gradi čelik koji ima sastav i kvalitetu; i periodičnog podizanja elektroda da bi se one udaljile od dodira sa kupaonom i zbog ometanja postupka izlijevanja; i zatim istakanja istopljenog metala. Osim toga, zgura se može ako je potrebno, ukloniti operacijom zgure ili odšljakivanja. Until now, the operation of the furnace for the production of steel using an electric arc was an operation with interruptions, where it was carried out in the following order: the introduction of steel waste and/or directly reduced iron, pig iron, slag-forming matter and alloying elements; ignition or establishment of an electric arc between the electrodes in the furnace to create conditions for melting the batch and for forming a bath of molten metal covered with molten slag; refining for a period of time during which part of the molten metal in the bath is refined so that it builds steel that has the composition and quality; and periodic lifting of the electrodes in order to move them away from contact with the bathroom and to interfere with the pouring process; and then highlighting the molten metal. In addition, the slag can, if necessary, be removed by a slag or de-slagging operation.

Opis rješenja tehničkog problema Description of the solution to the technical problem

Iako je ovaj izum prikazan i opisan u vezi sa peći sa električnim lukom za dobivanje čelika, veoma je jasno da se peć sa električnim lukom za dobivanje čelika može zamijeniti bilo kojom peći za dobivanje čelika na električni pogon, uključujući ali ne ograničavajući se na peći sa plazmom i indukcione peći sa sličnim rezultatom. Although the present invention has been shown and described in connection with an electric arc steelmaking furnace, it is to be understood that the electric arc steelmaking furnace may be substituted for any electrically powered steelmaking furnace, including but not limited to plasma and induction furnaces with a similar result.

Sada postoji praksa dobivanja čelika, poznata kao “kontinuirano šaržiranje” ili “kontinuirano topljenje”, ali ovi načini rada se odnose na praksu šaržiranja, kod koje se materijali koji se šaržiraju, uvode u peć u toku perioda šaržiranja, topljenja i rafiniranja, pa se zatim šaržiranje prekida, a prekida se i dovod električne energije radi postupka izlijevanja. There is now a practice of making steel, known as "continuous batching" or "continuous melting", but these methods of operation refer to the practice of batching, in which the materials to be batched are introduced into the furnace during a period of batching, melting and refining, so that then the batching is interrupted, and the electricity supply is also interrupted for the pouring process.

Nađeno je da električna peć za dobivanje čelika može da radi kontinuirano bez prekidanja šaržiranja ili dovođenja električne energije radi postupka izlijevanja, ako se u postupku dobivanja čelika primjene slijedeće faze rada. It was found that the electric furnace for obtaining steel can work continuously without interrupting the charging or supplying electricity for the pouring process, if the following stages of work are applied in the process of obtaining steel.

Prvo, otpaci se moraju pripremiti sječenjem ili lomljenjem na pogodnu krupnoću. Najbolje je da se otpaci razdvajaju radi kontrole kvaliteta. Onako kako su u primljeni otpaci se razdvajaju u željene klasifikacije, koje najbolje u zavisnosti od zaprljanosti pratećim elementima sumporom i fosforom. Razdvojeni otpaci željeza se sijeku ili lome i uskladište First, the waste must be prepared by cutting or breaking it to a suitable size. It is best to separate waste for quality control. As they are received, the waste is separated into the desired classifications, which are best depending on the contamination with the accompanying elements sulfur and phosphorus. Separated iron waste is cut or broken and stored

radi upotrebe. Održavanjem zaliha isječenog ili lomljenog sirovog materijala, osigurava se kontinuirani rad procesa u toku perioda kada se vrši sječenje ili kidanje. for use. By maintaining a stock of cut or broken raw material, continuous operation of the process is ensured during the period when cutting or tearing is performed.

Direktno reducirano željezo se normalno dobiva u obliku gruda ili granula, čija je krupnoća obično manja od 127mm u promjeru. Kao polazni materijal se može koristiti briketi direktno reduciranog željeza. Najbolje je da se takvo direktno reducirano željezo proizvodi u pogonu, koje se nalazi u susjedstvu. Directly reduced iron is normally obtained in the form of lumps or granules, the size of which is usually less than 127mm in diameter. Directly reduced iron briquettes can be used as starting material. It is best that such directly reduced iron is produced in the plant, which is located in the neighborhood.

Otpaci, direktno reducirano željezo, materijali koji grade šljaku i materijali za legiranje, predgrijavaju se i kontinuirano uvode u peć sa električnim lukom. Primjenjuje se praksa sa pjenušavom šljakom, pa se peć samo djelomično izlijeva sa prekidima bez uklanjanja elektroda, tako da električna energija ostaje pri punoj snazi za vrijeme kako kontinuiranog napajanja, rafiniranja (koje je kontinuirano) i izlijevanja (koje je s prekidima). Izlijevanje se izvodi ograničenim naginjanjem peći, koje obično ne varira za više od 15°C od vertikale. Scrap, direct reduced iron, slag building materials and alloying materials are preheated and continuously introduced into the electric arc furnace. A foamed slag practice is used, so the furnace is only partially poured intermittently without removing the electrodes, so that the electricity remains at full power during both continuous feeding, refining (which is continuous) and pouring (which is intermittent). Casting is performed by limited tilting of the furnace, which usually does not vary by more than 15°C from the vertical.

Glavni predmet ovog izuma je dobivanje postupka za kontinuirani rad električne peći za dobivanje čelika. The main object of this invention is to obtain a process for the continuous operation of an electric furnace for obtaining steel.

Isto tako je predmet ovog izuma dobivanje sredstva za predgrijavanje materijala koji se šaržiraju u električnu peć. The object of this invention is also to obtain a means for preheating materials that are charged into an electric furnace.

Drugi predmet ovog izuma je dobivanje postupka za kontinuirano dobivanje čelika uz dobru kontrolu kako kvaliteta tako i kemijskog postupka za dobivanje proizvoda. Another object of this invention is to obtain a process for continuous production of steel with good control of both the quality and the chemical process for obtaining the product.

Jedan daljnji predmet ovog izuma je dobivanje postupka za izlijevanje električne peći uz održavanje cjelokupne električne snage. A further object of this invention is to provide a process for pouring an electric furnace while maintaining overall electrical power.

Daljnji predmet ovog izuma je dobivanje postupka za rad električne peći, kojim se poboljšava faktor opterećenja peći i njezina prihvatljivost kao potrošača energije. A further object of this invention is to obtain a method for the operation of an electric furnace, which improves the load factor of the furnace and its acceptability as an energy consumer.

Također je predmet ovog izuma dobivanje sredstva za kontinuirano topljenje vrućeg direktno reduciranog željeza iz susjednog postrojenja za direktnu redukciju. The subject of this invention is also obtaining means for continuous melting of hot directly reduced iron from the adjacent direct reduction plant.

Gornji i drugi predmeti postaju lako vidljivi na osnovu slijedećeg detaljnog opisa i priloženih crteža na kojima je: The above and other objects become easily visible based on the following detailed description and the attached drawings, which show:

slika 1 shematski dijagram faza rada u postupku prema izumu Figure 1 is a schematic diagram of the work phases in the process according to the invention

slika 2 shematski tlocrt peći sa električnim lukom i sve pripadajuće opreme, kako je opisana u sadašnjem izumu figure 2 is a schematic floor plan of an electric arc furnace and all associated equipment, as described in the present invention

slika 3 je shematski poprečni presjek peći sa električnim lukom kako je ovdje opisana Figure 3 is a schematic cross-section of an electric arc furnace as described herein

Prema crtežima, peć (10) sa električnim lukom za dobivanje čelika ima tri elektrode (12) koje prodiru na dolje u peć. Ove elektrode se napajaju iz transformatora (ili izvora električne energije) (14). Za uvođenje čitavog materijala kako metalnog tako i nemetalnog koji se šaržira u peći predviđen je kanal (16). According to the drawings, the electric arc furnace (10) for obtaining steel has three electrodes (12) which penetrate downward into the furnace. These electrodes are powered from a transformer (or power source) (14). A channel (16) is provided for the introduction of the entire material, both metallic and non-metallic, which is batched in the furnace.

Kanal je pokriven i u njemu se nalazi plamenik s kisikom (18) za predgrijavanje materijala koji se šaržira i sagorijevanje materijala, koje se mogu spaliti. Najbolje je da se kanal hladi vodom i da je pokriven tunelom (20) od segmenata vatrostalne opeke tako da gradi prolaz za izlazne plinove iz peći. The channel is covered and contains an oxygen burner (18) for preheating the material to be batched and burning the materials that can be burned. It is best if the channel is cooled with water and is covered with a tunnel (20) made of refractory brick segments so that it creates a passage for the exit gases from the furnace.

Na izlazu iz tunela (20) postavljen je senzor kisika (22). An oxygen sensor (22) is installed at the exit from the tunnel (20).

Radi uklanjanja šljake, predviđen je lonac (24) za šljaku na pomičnim kolicima (25) postavljenim na tračnicama, tako da se može pomicati u i iz položaja za stvaranje šljake, a u svrhu izlijevanja je predviđen i čelični lonac (26) na prijenosnim kolicima (27) radi pomicanje u položaj i iz položaja za ispuštanje, kontinuiranu metalurgiju u loncu i izlijevanje. Lonac se može izlijevati direktno u kontinuirani uređaj (28) za lijevanje. In order to remove slag, a pot (24) for slag is provided on movable carts (25) placed on rails, so that it can be moved in and out of the position for slag formation, and for the purpose of pouring, a steel pot (26) on portable carts (27) is provided. ) for moving in and out of drop position, continuous pot metallurgy and pouring. The pot can be poured directly into the continuous casting device (28).

Uređaj za obradu sirovog materijala sastoji se od stanice (30) za prihvat otpadaka, zona ili koševa (32A, 32B itd.), za razdvajanje otpadaka i pokretnog krana za šaržiranje sirovih materijala u uređaj (34) za sječenje ili lomljenje. Uređaj (34) za sječenje/lomljenje se prazni na transportnu traku koja prenosi male izdvojene otpatke u odgovarajuće zone (36A, 36B itd.) za skladištenje odvojenih otpadaka. Direktno reducirano željezo i/ili sirovo željezo se skladišti u zoni (38). Drugi kran je predviđen za šaržiranje materijala iz skladišnih zona (36) i (38) na transportnu traku (44). Transportna traka ulazi u tunel (20) kroz dinamički zatvarač (48). Oprema za obradu plinova je povezana sa tunelom u blizini plinskog zatvarača (48). The device for processing raw materials consists of a station (30) for accepting waste, zones or baskets (32A, 32B, etc.), for separating waste and a mobile crane for charging raw materials into a device (34) for cutting or breaking. The cutting/breaking device (34) is discharged onto a conveyor belt which conveys the small separated waste to the appropriate zones (36A, 36B, etc.) for the storage of separated waste. Directly reduced iron and/or pig iron is stored in zone (38). The second crane is designed for loading materials from the storage areas (36) and (38) onto the conveyor belt (44). The conveyor belt enters the tunnel (20) through the dynamic shutter (48). The gas processing equipment is connected to the tunnel near the gas seal (48).

Sistem za tretiranje vrućeg izlaznog plina sastoji se od veze sa tunelom, parnog kotla (50) komore (52) za otprašivanje, dimnjaka (54) i pripadajućih cjevovoda. Cijev (56) koja povezuje plinsku cijev (58) između parnog kotla i komore za otprašivanje osigurava plin za zatvaranje plinskog zatvarača na ulazu u tunel. Plamenik (60) u prolazu (62) za plin zagrijava i topi čestice u plinu koje se zatim talože u jami (64) za šljaku. Na izlazu plina iz tunela nalazi se senzor (66) kisika, radi određivanja odnosa gorivo-zrak koji je potreban da bi plamenik (60) potpuno sagorijevao izlazni plin. The system for treating the hot exhaust gas consists of a connection with the tunnel, a steam boiler (50), a chamber (52) for dedusting, a chimney (54) and associated pipelines. The pipe (56) connecting the gas pipe (58) between the steam boiler and the dedusting chamber provides gas to close the gas shutter at the entrance to the tunnel. The burner (60) in the gas passage (62) heats and melts the particles in the gas, which are then deposited in the slag pit (64). At the gas exit from the tunnel, there is an oxygen sensor (66) to determine the fuel-air ratio required for the burner (60) to completely burn the exit gas.

Peć (10), premda prikazana kao trofazna peć sa električnim lukom, alternativno može biti i električna peć na jednosmjernu struju, peć sa plazmom ili indukciona peć. Najpogodniji tip indukcione peći bi bila kanalska indukciona peć. Treba koristiti suvremene komponente za električne peći, uključujući izmjenjivi lonac ili rasječenu školjku, vodom hlađenje zidne ploče za peć i vodom hlađen krov peći. Do sada nikakav praktičan način izlijevanja nije dozvoljavao kontinuirano topljenje u neprekidnom toku The furnace (10), although shown as a three-phase electric arc furnace, could alternatively be a direct current electric furnace, a plasma furnace, or an induction furnace. The most suitable type of induction furnace would be a channel induction furnace. Modern electric furnace components should be used, including a replaceable pot or split shell, water-cooled furnace wall plate, and water-cooled furnace roof. Until now, no practical pouring method allowed continuous melting in a continuous flow

24 sata. Sadašnji izum dozvoljava kontinuirano šaržiranje i rafiniranje sa punim napajanjem peći električnom energijom iskretanjem peći radi uklanjanja šljake i izlijevanja za ne više od 15°. Da bi se omogućio kontinuirani rad pri punoj snazi, sa elektrodama koje ostaju u dodiru sa kadom i bez oštećenja dan peći, unutar kade se održava ostatak istopljenog metala koji ima približno isti volumen kao i istopljeni metal koji se uklanja pri svako izlijevanju, ili kod svake šarže. To znači da, poslije izlijevanja treba zadržati ostatak istopljenog metala približno 50% od maksimalne visine kade. 24 hours. The present invention permits continuous batching and refining with full electric power to the furnace by turning the furnace for slag removal and pouring by no more than 15°. In order to allow continuous operation at full power, with the electrodes remaining in contact with the bath and without damaging the furnace, a residual molten metal is maintained within the bath of approximately the same volume as the molten metal removed at each pouring, or at each batches. This means that, after pouring, the rest of the molten metal should be kept approximately 50% of the maximum height of the tub.

Na slici 3 je prikazana peć (10) za dobivanje čelika. Nivo maksimalne visine kada naznačen je linijom (72) na kadi, a minimalna visina kade je pokazana kod linije (74) na kadi. Figure 3 shows the furnace (10) for obtaining steel. The level of the maximum height of the bathtub is indicated by the line (72) on the bathtub, and the minimum height of the bathtub is indicated by the line (74) on the bathtub.

Ostatak (76) istopljenog metala čini kade koji nalazi ispod linije (74) minimalne kade. U peći se ispod linije (72) kade nalazi se jedna ili više puhaljka i propusnih mlaznica (78). U zidu peći, na bilo kojem željenom položaju ispod linije (74) minimalne kade, nalazi se izlijevni uređaj (80) sa kliznim zatvaračem. Ovaj položaj sprječava uklanjanje šljake iz peći kroz uređaj za izlijevanje sa kliznim zatvaračem. The rest (76) of the molten metal forms the tub located below the line (74) of the minimum tub. In the furnace, under the line (72) of the tub, there is one or more blowers and permeable nozzles (78). In the wall of the furnace, at any desired position below the line (74) of the minimum tub, there is a pouring device (80) with a sliding closure. This position prevents the removal of slag from the furnace through the sliding shutter pouring device.

Položaj za uvođenje šarže, u odnosu na peć, naznačeni su na gornjem dijelu peći na slici 3. U normalnom radnom položaju materijal šarže se uvodi u položaju A. U toku operacije izlijevanja, materijal šarže se uvodi u položaju B, koji predstavlja nagib peći od 15°C. The position for introducing the batch, in relation to the furnace, is indicated on the upper part of the furnace in Figure 3. In the normal working position, the material of the batch is introduced in position A. During the pouring operation, the material of the batch is introduced in position B, which represents the slope of the furnace from 15°C.

Premda i otvor za odšljakivanje i otvor za izlijevanje mogu biti na istoj strani posude peći, slika 3 pokazuje da se posuda može biti nagnuti u suprotnom smjeru od izlijevanja radi formiranja šljake, pri čemu je položaj za dovođenje materijala onakav kakav je označen sa C. Although both the slagging opening and the pouring opening may be on the same side of the furnace vessel, Figure 3 shows that the vessel may be tilted in the opposite direction to the pouring to form the slag, the feed position being as indicated by C.

Postupak prema izumu može da koristi bilo koju od čitavog niza tehnika izlijevanja, uključujući klasični otvor za izlijevanje, izlijevanje preko kljuna lonca, klizni zatvarač i druge. The process of the invention may employ any of a variety of pouring techniques, including conventional spigot pouring, spout pouring, slide closure, and others.

Materijal šarže za kontinuirano topljenje su otpaci željezo i direktno reducirano željezo u obliku zrnaca ili briketa. Otpatci se odvajaju prema stupnju čistoće, isječeni ili izlomljeni na veličinu pogodnu za kontinuirano uvođenje u peć i ostavljaju se na skladište prema kvalitetu sortirani sve dok nisu potrebni za uvođenje u peć. Sirovo željezo se granulira ili lomi na pogodnu krupnoću da se može koristiti za uvođenje u peć. The batch material for continuous melting is scrap iron and directly reduced iron in the form of pellets or briquettes. The scraps are separated according to the degree of purity, cut or broken into a size suitable for continuous introduction into the furnace and left in the warehouse, sorted by quality, until they are needed for introduction into the furnace. The pig iron is granulated or broken to a suitable size so that it can be used for introduction into the furnace.

Materijal za šaržiranje se odabire od uskladištenog isječenog ili izlomljenog materijala ili drugih sirovina, izmjerenog i stavljenog na transportnu traku. Najbolje je da se materijal za šaržiranje mjeri na mjernoj transportnoj traci. Materijal za šaržiranje se predgrijava u tunelu (20) provođenjem plina koji izlazi iz peći kroz njega i preko njega, protustrojno kretanju šarže ka peći. Senzor (22) kisika pokazuje da li je izlazni plin dovoljno redukcionog karaktera da spriječi oksidaciju šarže, i kontrolira podešavanje plamenika u tunelu. Nemetalne sagorljive materije u šarži se spaljuju, a šarža se zagrijava na približno 800°C do 1000°C. Konačni plamenik (18), smješten na kraju kanala (20), daje dodatnu toplinu potrebnu za podizanje temperature šarže na željeni nivo, tako da se ona uvodi u peć sa 800°C do 1000°C. Batching material is selected from stored cut or broken material or other raw materials, weighed and placed on the conveyor belt. It is best to measure the material for batching on a measuring conveyor belt. The material for batching is preheated in the tunnel (20) by passing the gas coming out of the furnace through it and over it, against the movement of the batch towards the furnace. The oxygen sensor (22) indicates whether the outlet gas is sufficiently reducing in character to prevent oxidation of the batch, and controls the adjustment of the burner in the tunnel. The non-metallic combustibles in the batch are burned, and the batch is heated to approximately 800°C to 1000°C. The final burner (18), located at the end of the channel (20), provides the additional heat necessary to raise the temperature of the batch to the desired level, so that it is introduced into the furnace from 800°C to 1000°C.

Peć za dobivanje čelika radi kontinuiranog i pod punom snagom u toku dužeg perioda do oko približno šest do sedam dana, u toku kojeg se na peći ne vrše nikakve popravke. Poslije ovoga vremena peć se zaustavlja, pa se čitav lonac ili rasječena školjka zamjenjuje. The steelmaking furnace operates continuously and at full power for a long period of time, up to approximately six to seven days, during which no repairs are made to the furnace. After this time, the furnace is stopped, so the whole pot or the cut shell is replaced.

Peć radi sa ostatkom istopljenog metala koji je po težini približno jednak količini u tonama, koja se odvodi pri svakom izlijevanju. Ovim se zaštićuje dno peći od jakog dovođenja električne energije u toku i neposredno poslije izlijevanja. The furnace works with a residue of molten metal, which by weight is approximately equal to the amount in tons, which is removed with each pouring. This protects the bottom of the furnace from a strong supply of electricity during and immediately after pouring.

Brzina šaržiranja ili napajanja se određuje željenim kolebanjem temperature kade. Kada se približi vrijeme izlijevanja, brzina uvođenja šarže u peć se smanjuje nekoliko minuta prije izlijevanja. Smanjivanjem efekta podhlađivanja šarže na kadi, temperatura kade se povisuje do željene temperature izlijevanja. The rate of batching or feeding is determined by the desired temperature fluctuation of the bath. When pouring time approaches, the rate of introduction of the batch into the furnace is reduced several minutes before pouring. By reducing the subcooling effect of the batch on the bath, the temperature of the bath is raised to the desired pouring temperature.

Šljaka se održava u stanju pjenušanja u toku svih faza procesa, uključujući fazu izlijevanja, a u toku izlijevanja se održava puni dovod električne energije u peć. Pjenušanje šljake se izaziva oslobađanjem CO i CO2 unutar šljake. Ugljik potreban za reakciju s kisikom (oksidom) u šarži ubrizgava se, u kadi u obliku prašine ugljika ili koksa, kroz jednu ili više puhala (78) postavljenih ispod kade (vidi sliku 3). Ako je u kadi prisutna nedovoljna količina kisika, kroz puhala ispod kade može se ubrizgavati i kisik, da bi se ostvarila potrebna reakcija sa ugljikom i potpomoglo pjenušanje šljake. Ugljik i/ili kisik se mogu ubrizgavati u kadu u bilo koje vrijeme. The slag is kept in a state of foaming during all stages of the process, including the pouring stage, and during the pouring the full supply of electricity to the furnace is maintained. Slag foaming is caused by the release of CO and CO2 within the slag. The carbon required for the reaction with oxygen (oxide) in the batch is injected, in the bath in the form of carbon dust or coke, through one or more blowers (78) placed under the bath (see Figure 3). If there is an insufficient amount of oxygen in the bath, oxygen can be injected through the blowers under the bath, in order to achieve the necessary reaction with carbon and help the foaming of the slag. Carbon and/or oxygen can be injected into the bath at any time.

Defosforizacija, oksidacija i karburizacija se izvode unutar peći. Međutim, u procesu poznatim kao metalurgija u loncu, deoksidacija, desulfurizacija i legiranje se izvode u loncu poslije izlijevanja, a takva dodavanja se vrše iz zone (82) za metalurgiju u loncu. Čelik u loncu je slobodan od istopljene šljake, te se, kada se proizvode čelici uobičajenih kvaliteta legirajući elementi mogu dodavati u toku procedure izlijevanja. Stvaratelji šljake se dodaju dok plin u mjehurima prolazi kroz čelik, čime se poboljšava homogenost čistoća. Dephosphorization, oxidation and carburization are performed inside the furnace. However, in a process known as crucible metallurgy, deoxidation, desulfurization and alloying are carried out in the crucible after pouring, and such additions are made from the crucible metallurgy zone (82). The steel in the crucible is free from molten slag, and when steel of ordinary quality is produced, alloying elements can be added during the pouring procedure. Slag formers are added as the gas in the bubbles passes through the steel, thus improving the homogeneity of the purity.

Da bi se izvelo izlijevanje iz peći, ona se naginje do 15° od normalnog vertikalnog položaja. Peć se može izlijevati bilo kojom tehnikom izlijevanja, ali najbolje da se izlijevanje vrši pomoću uređaja sa izlijevnim otvorom, koji se regulira kliznim zatvaračem. Ovim se omogućuje sprečavanje prisustva istopljene šljake u loncu. To perform pouring from the furnace, it is tilted up to 15° from the normal vertical position. The stove can be poured using any pouring technique, but it is best to pour using a device with a pouring opening, which is regulated by a sliding shutter. This makes it possible to prevent the presence of molten slag in the pot.

Ugljik, kreč, kisik ili stvaratelji pjenušave šljake mogu se ubrizgavati preko zamjenjive mlaznice za ubrizgavanje ili puhala (78) ispod nivoa kade istopljenog metala ili međupovršinu šljaka-metal. Carbon, lime, oxygen or foaming slag formers can be injected via a replaceable injection nozzle or blower (78) below the level of the molten metal bath or the slag-metal interface.

Slijedi primjer izvođenja postupka prema izumu. The following is an example of performing the procedure according to the invention.

Primjer Example

Entalpija čelika na temperaturi izlijevanja od 1660°C je oko 347.000 kcal po metričkoj toni. Ubacivanjem 100% otpadaka, sa normalnom potrošnjom kisika od oko 10 Nm3 po metričkoj toni, bez plamenika i bez predgrijavanja, potrošnja električne energije u peći sa šaržom od 80 tona, iznosi oko 520 kWh po toni. The enthalpy of steel at the pouring temperature of 1660°C is about 347,000 kcal per metric ton. By inserting 100% waste, with a normal oxygen consumption of about 10 Nm3 per metric ton, without a burner and without preheating, the electricity consumption in a furnace with a batch of 80 tons is about 520 kWh per ton.

Dodatna toplina koja se razvija u peći (zbog topline reakcije, oksidacije elektroda, sagorijevanje materijala u šljaki koje mogu sagorijevati itd.) je oko 190.000 kcal po metričkoj toni ili ekvivalentno 217 kWh po metričkoj toni. The additional heat developed in the furnace (due to heat of reaction, oxidation of the electrodes, combustion of combustible materials in the slag, etc.) is about 190,000 kcal per metric ton or equivalent to 217 kWh per metric ton.

Vodenim hlađenjem peći odvodi se oko 63.000 kcal po metričkoj toni čelika ili 73 kWh, a šljaka zahtijeva oko 60.200 kcal po metričkoj toni ili 70 kWh. Na taj način se iz izlaznog plina može upotrijebiti za predgrijavanje sirovina ili materijala koji se šaržira, oko 160 kWh ili 137.600 kcal po metričkoj toni. Water cooling of the furnace takes away about 63,000 kcal per metric ton of steel or 73 kWh, and slag requires about 60,200 kcal per metric ton or 70 kWh. In this way, about 160 kWh or 137,600 kcal per metric ton can be used from the output gas to preheat raw materials or materials that are being batched.

Entalpija jedne metričke tone čeličnih otpadaka na 900°C je oko 160.200 kcal ili 186 kWh, a efikasnost prijenosa topline je oko 40% za predgrijavanje isječenih ili izdrobljenih otpadaka. Ukupna potrebna toplina je tada 400.500 kcal po metričkoj toni. The enthalpy of one metric ton of steel scrap at 900°C is about 160,200 kcal or 186 kWh, and the heat transfer efficiency is about 40% for preheating cut or crushed scrap. The total required heat is then 400,500 kcal per metric ton.

Potrebna čista toplina, uzevši u obzir raspoloživu toplinu iz izlaznog plina iz peći, je 400.500 - 137.60 = 262.900 kcal po metričkoj toni. The required clean heat, taking into account the available heat from the exit gas from the furnace, is 400,500 - 137,60 = 262,900 kcal per metric ton.

Energija potrebna za topljenje predgrijane šarže i pregrijavanja istopljenog metalne kade do temperature izlijevanja od 1660°C je 520 - (186/0,78) = 282 kWh po metričkoj toni. The energy required to melt the preheated batch and superheat the molten metal vat to the pouring temperature of 1660°C is 520 - (186/0.78) = 282 kWh per metric ton.

Kada se kao sirovina koristi direktno reducirano željezo, smanjuje se potrošnja prirodnog plina. When directly reduced iron is used as a raw material, the consumption of natural gas is reduced.

Iz gore navedenog je jasno da sam pronašao postupak za kontinuirani rad električne peći za proizvodnju čelika, sa sredstvom za predgrijavanjne materijala koji se šaržiraju, za šaržiranje i izlijevanje uz zadržavanje pune električne snage, i koji ima dobru kontrolu kako kvaliteta tako i kemijskog postupka za dobijanje proizvoda. From the above it is clear that I have found a process for the continuous operation of an electric furnace for steelmaking, with a means of preheating the materials being batched, for batching and pouring while maintaining full electrical power, and which has good control of both the quality and the chemical production process products.

Claims

1. Process for continuous refining of steel, characterized by the fact that it consists in: obtaining scraps containing iron that are used in cut, broken or granulated form; separation of obtained waste; preheating of the obtained waste; the introduction of waste containing iron, directly reduced iron or their mixture into the furnace for obtaining steel with electric drive for melting and refining in it; introducing a slag creator into the steelmaking furnace; introduction of carburizing agents into the furnace for steel production; heating the batch electrically to melt the batch and create a molten metal bath within the furnace, with a layer of molten slag on said molten metal bath: maintenance of said slag in foaming conditions during the steel production process; continuous introduction of metal materials, slag generators and carburizing agents into the specified furnace; maintaining full electrical power in the said furnace all the time during the batching, melting and refining operation; and pouring of the specified furnace with continuous supply of raw materials to the specified furnace.

2. The process according to claim 1, characterized by the fact that hot reaction gases are generated in the said furnace, and that the said hot gases are conducted through and over the said wastes for the purpose of preheating the wastes and burning non-metallic substances in the wastes.

3. The method according to claim 1, characterized in that said slag is maintained in a foaming state.

4. The method according to claim 3, characterized by the fact that the stated state of foaming is assisted by injecting pulverized carbon into the tub below the surface of the tub.

5. The method according to claim 1, characterized in that during the pouring operation the temperature of the molten metal tub is maintained between 1540° and 1660°C.

6. The method according to claim 1, characterized by the fact that during the melting process, the temperature of the molten metal tub is maintained in the range of about 1540° to 1560°C.

7. The method according to claim 1, characterized by the fact that the composition in the bath is periodically controlled and that the separated material, which is introduced, is selected and introduced into the specified molten metal bath according to the required quality of the desired end product.

8. The method according to claim 1, characterized in that the slag formers are selected from the group consisting of powdered lime, fluorite, alumina, carbon and iron oxide.

9. The method according to claim 1, characterized in that the temperature of said tub is increased immediately before pouring.

10. The method according to claim 9, characterized in that the specified bath temperature is increased by injecting oxygen into the specified molten bath.

11. The method according to claim 1, characterized by the fact that the stated temperature of the tub is lowered immediately after pouring.

12. The method according to claim 11, characterized in that the stated temperature of the bath is lowered by increasing the rate of introduction of the materials to be batched.

13. The process according to claim 1, characterized in that approximately half of the said molten metal tub is removed by pouring and that the rest is retained in the said furnace as a residue that receives continuously batched raw materials.

14. The method according to claim 1, characterized in that the said pouring operation is performed by pouring over the spout of the pot.

15. The method according to claim 1, characterized in that the requested furnace has a pouring nozzle that is regulated by a sliding shutter at or below the slag-metal interface and that said pouring operation is performed by tilting said furnace no more than 15° for pouring through said nozzle.

16. Device for continuous refining of steel, characterized by the fact that it consists of: - furnaces for the production of steel with an electric arc for melting and refining the metal batch in it; - electrodes that enter the specified furnace below the level of the molten metal tub, which should be located in it; - the introduction means related to the said furnace for the purpose of introducing materials, which are batched into the interior of the said furnace; - means related to the said means of introduction for preheating the materials that are batched inside the said means of introduction; - means for gas sealing in order to achieve a controlled atmosphere inside the specified introduction means; - means for gas injection that are in connection with the mentioned furnace below the normal level of the molten metal tub; and - means for tilting the mentioned furnace up to 15° from the vertical, which enable slag removal and pouring without removing the mentioned electrodes.

17. Device for the continuous production of molten steel from directly reduced iron, characterized by that, which consists of: - source of hot directly reduced iron; - electric arc furnaces for steel production; - electrodes that enter the mentioned furnace for the purpose of melting and refining the molten metal batch in it; - means for introduction, which is related to the said furnace for the purpose of introducing directly reduced iron and other materials that are batched into the interior of the said furnace; - a means that is related to the said introduction means for the purpose of preheating the materials that are batched inside the said introduction means; - means with a gas seal in order to ensure a controlled atmosphere inside the said introduction means; - means for injecting gas that is below the normal level of the molten metal tub in connection with the mentioned furnace; - means for tilting said furnace up to 15° from vertical, which enables slag removal and pouring without removing the electrodes; - a pot placed on a cart arranged to receive molten steel after each pouring from the said furnace; and - stations for metallurgy in the crucible arranged in such a way that it stands in connection with the said crucible.