SE182532C1

SE182532C1 -

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Publication number: SE182532C1
Authority: SE
Publication date: 1962-01-01

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KLASS 31 a:1/ INT. KLASS 822 b PATENTTID FRAN DEN 7 MA] 1953 BEVIDAT DEN 15 NOVEMBER 1962 PUBLICERAT DEN 12 FEBRUARI 1963 Ans. 4283/1953 den 7/5 1953Hârtill tvd ritningar R DOAT, LIEGE, BELGIEN Sid och kupolugn for framstallning av gjutjarn eller tackjarn av eventuellt oxidhaltigt jarnmaterial Prioritet begtird frem den 15 maj 1952 (USA) Foreliggande uppfinning hanfor sig till ett satt att framstalla gjutjarn eller tackjarn i en kupolugn och en for genomforande av sattet lamplig kupolugnsanlaggning. Sattet och ugnsanlaggningen enligt uppfinningen lam-pa sig sarskilt fOr framstallning av legerat eller olegerat jam.fOr gjutning. Uppfinningen grundar sig pa den upptackten, att man for att kunna beharska reaktionerna i ugnen Indian metallen, branslet och den vid smaltningen bildade slaggen maste uppratthalla en atmosfar, som Or reducerande vid den ifragakommande temperaturen i forhallande till jarnoxid. Detta fordrar vidtacandet av en rad skilda atgarder. Salunda maste branslet tillforas i sadant overskott i farhallande till den mangd, som gar at fOr alstrande av erforderligt varme samt for uppkolning av stalskrot och for reducering av metalloxider och kiseloxider, som inga i beskiekningen, att man far den ovannamnda reducerande atmosfaren i ugnen. Sasom bekant har syre starkare affinitet for kisel an for kol vid lagre temperatur, medan affiniteten for kol blir starkare vid hogre temperatur. Av denna anledning maste ugnen enligt uppfinningen drivas med avsevart hogre temperatur an vanliga kupolugnar. Pa grund harav forvarmes blastern, som kan best& av luft, eventuellt syreanrikad, till en temperatur av cirka 400-600° C, och biases in i ugnen med hog hastighet, dvs. Over 80 m/s, sa att det i ugnen vid formnivan bildas en koncentrerad bogtemperaturzon. Eftersom en sadan hOg temperatur i samband med reducerande forhallande utsatter ugnens foder for mycket stora pakanningar, maste man vidtaga algarder for att skydda fodret. For den skull later man formorna mynna minst 50 mm innanfor fodrets insida, lampligen cirka 50-150 mm, samt kyler ugnen pd utsidan med strilande vatten. CLASS 31 a: 1 / INT. CLASS 822 b PATENT PERIOD FROM 7 MAY 1953 PROVIDED 15 NOVEMBER 1962 PUBLISHED 12 FEBRUARY 1963 Ans. 4283/1953 on 7/5 1953In addition to two drawings R DOAT, LIEGE, BELGIUM Side and dome furnace for the production of cast iron or pig iron from any oxide-containing iron material Priority started on 15 May 1952 (USA). pig iron in a dome furnace and a dome furnace installation suitable for carrying out the set. The set and the furnace installation according to the invention are particularly suitable for the production of alloy or non-alloy iron for casting. The invention is based on the discovery that in order to be able to control the reactions in the furnace, the Indian metal, the industry and the slag formed during the melting must maintain an atmosphere which is reducing at the temperature in question in relation to iron oxide. This requires the adoption of a number of different measures. Thus, the fuel must be supplied in such a surplus in relation to the quantity which is necessary for the generation of the required heat and for the carbonization of scrap metal and for the reduction of metal oxides and silicas, which are not in the order to obtain the above-mentioned reducing atmosphere in the furnace. As is well known, oxygen has a stronger affinity for silicon than for carbon at lower temperatures, while the affinity for carbon becomes stronger at higher temperatures. For this reason, the furnace according to the invention must be operated at a considerably higher temperature than ordinary dome furnaces. Due to this, the blaster, which may consist of air, possibly oxygen-enriched, is preheated to a temperature of about 400-600 ° C, and biased into the oven at high speed, ie. Above 80 m / s, so that a concentrated arc temperature zone is formed in the furnace at the mold level. Since such a high temperature in connection with reducing conditions exposes the furnace's feed to very large packing pans, algae must be taken to protect the feed. For this purpose, the molds are allowed to open at least 50 mm inside the inside of the lining, preferably about 50-150 mm, and the oven is cooled on the outside with sprinkling water.

Sattet enligt uppfinningen kannetecknas sa.- lunda av kombinationen av att ugnen beskickas med jarnmaterialet samt bransle i sit stort overskott i farhallande till den mangd som fordras for uppnaende av onskad ugnstemperatur samt for uppkolning av stalskrot och fOrekommande reducering av metalloxider och kiseloxider som eventuellt ingit i beskickningen, att en mot jarnoxid reducerande atmostar uppnas i schaktet, att basiska slaggbildare tillsattas i sadan mangd, att den bildade slaggen blir basisk, att ugnens utsida kyles med vatten, att blastern forvarmes till en temperatur av cirka 400-600° C och inblases med en hastighet av Over 80 m/sek genom vattenkylda formor som mynna ett vasentligt stycke, lampligen minst 50 mm, innanfor ugnens innervagg samt att smalt metall och slagg kontinuerligt avtappas vid ugnens botten pa sit satt, att i huvudsak konstant slaggdjup uppratthalles i kupolugnen. The method according to the invention can thus be characterized by the combination of the furnace being loaded with the iron material and the industry in its large surplus in relation to the amount required to achieve the desired furnace temperature and to carbonize scrap steel and prevent reduction of metal oxides and silicas. that an iron-reducing atom is obtained in the shaft, that basic slag formers are added in such an amount that the slag formed becomes alkaline, that the outside of the furnace is cooled with water, that the blaster is preheated to a temperature of about 400-600 ° C and blown in with a speed of Over 80 m / sec through water-cooled molds that open a substantial piece, preferably at least 50 mm, inside the oven's inner cradle and that narrow metal and slag are continuously drained at the bottom of the oven in such a way that substantially constant slag depth is maintained in the dome furnace.

Till foljd av den reducerande almosfaren i ugnen blir det mojligt att paverka slaggens surhetsgrad, sit att kisel, som i form av olika foreningar eller legeringar ingar i beskickningen, foretradesvis gar med metallen, sit att man genom tillsats av basiska slaggbildare kan fa en basisk slagg utan minskning av metallens kiselhalt. Genom den hOga temperaturen i ugnen framfOr allt i formnivan upphettas bade metallen och slaggen starkt, sit att man utan olagenhet kan arbeta med starkt basiska slagger. Dessa ha sasom bekant stor formaga att reagera med metallen fOr genomforande av olika metallurgiska reaktioner, sasom avs-vavling. For att dessa skola forlopa likformigt, maste reaktionsforhallandena hallas sit likformiga som majligt. Av denna anledning arbetar man med ett slaggbad av konstant djup, vilket den smalta me-fallen maste passera ph sin vag mot ugnens botten. Bade slaggen och metallen tappas darfor kontinuerligt pit sadant salt, att ett slaggbad med konstant djup uppratthalles i ugnen. Detta konstanta djup pa slaggbadet uppnas genom att man tappar bade metallen och slaggen mot ett konstant, statiskt tryck genom 2— — anvandning av en sifonanordning av i och for sig kand typ, dvs. ett yttre med braddavlopp- forsett karl, som kommunicerar med metall- resp. slaggbadet vid ugnsbottnen genom en eller flera under vatskenivam belagna kanaler. As a result of the reducing hazardousness in the furnace, it becomes possible to influence the acidity of the slag, since silicon, which in the form of various compounds or alloys in the charge, preferably goes with the metal, provided that by adding basic slag formers a basic slag can be obtained. without reducing the silicon content of the metal. Due to the high temperature in the oven, above all in the mold level, both the metal and the slag are strongly heated, meaning that it is possible to work with strongly alkaline slag without malfunction. These are known to have a great ability to react with the metal to carry out various metallurgical reactions, such as desulphurisation. In order for these schools to proceed uniformly, the reaction conditions must be kept as uniform as possible. For this reason, one works with a slag bath of constant depth, which the narrow me-falls must pass ph its vague towards the bottom of the oven. Both the slag and the metal are therefore continuously dropped into such a salt that a slag bath with a constant depth is maintained in the furnace. This constant depth of the slag bath is achieved by dropping both the metal and the slag against a constant, static pressure by using a siphon device of a per se known type, ie. an exterior with a brad drain - intended man, who communicates with metal resp. the slag bath at the bottom of the furnace through one or more channels covered under the water level.

Som en foljd av de enligt uppfinningen vidtagna atgarderna blir angreppet pa ugnens foder sä ringa, att man aven vid anvandning av basiska slagger kan fodra in ugnen med surt foder, bestaende av stampmassa. I prakliken har det visat sig lampligt att blanda in en viss mangd kol i stampmassan, vilket Sr mojligt ph grund av den reducerande atmosfaren i ugnen. En p5 delta salt infodrad ugn kan vid tillampning av ovriga atgarder enligt uppfinningen drivas totalt cirka 100 timmar utan reparation av fodret, medan normala kupolugnar endast sallan drivas langre an 8 timmar, innan det blir nodvandigt att utfora reparationer. I ugnen enligt uppfinningen begransas angreppet p5 fodret huvudsakligen till skiljeytan mellan metallen och slaggen, varfor nyssnamnda foder endast behover anvandas ett mindre stycke upp i ugnen oven-for formnivan. Dar ovanfor kan fodret vara av annat slag eller helt uteslutas. As a result of the measures taken according to the invention, the attack on the furnace lining becomes so small that even with the use of basic slag, the furnace can be lined with acidic lining, consisting of stamping compound. In practice, it has proved appropriate to mix a certain amount of carbon into the stamping compound, which is possible due to the reducing atmosphere in the furnace. When applying other devices according to the invention, a p5 delta salt lined oven can be operated for a total of about 100 hours without repair of the lining, while normal dome furnaces are only operated for longer than 8 hours, before it becomes necessary to carry out repairs. In the furnace according to the invention, the attack on the lining is limited mainly to the dividing surface between the metal and the slag, for which reason the aforementioned lining only needs to be used a small distance up in the furnace above the mold level. Above, the feed may be of a different kind or completely excluded.

Uppfinningen kommer i det foljande att beskrivas narmare under hanvisning till bifogade ritningar, vilka som exempel visa en utfiiringsforin. Fig. 1 Sr en sidovy av en ugn enligt foreliggande uppfinning med vissa delar visade i snitt efter linjen 1-1 i fig. 3 i pilarnas riktning. Fig. 2 Sr en vy framifran av nedre delen av ugnen enligt fig. 1 sedd fran linjen 2-2 i fig. 3 i pilarnas riktning. Fig. 3 visar ett horisontalsnitt genom ugnen enligt fig. 1 taget genom ugnens schakt och sett nedat. Fig. 4 visar ett diametralsnitt genom nedre delen av ugnen. Fig. 5 visar en sektion i stone skala efter linjen 5-5 i fig. 4 i pilarnas riktning. Fig. 6 visar ett snitt efter linjen 6-6 i fig. 4 och 5 i pilarnas riktning. Fig. 7 Sr en sidovy av en del av ugnen enligt fig. 2 sedd frau hogra sidan. Fig. 8 visar en detalj av kupolugnen. The invention will be described in more detail below with reference to the accompanying drawings, which show by way of example an embodiment. Fig. 1 is a side view of an oven according to the present invention with certain parts shown in section along the line 1-1 in Fig. 3 in the direction of the arrows. Fig. 2 is a front view of the lower part of the oven according to Fig. 1 seen from the line 2-2 in Fig. 3 in the direction of the arrows. Fig. 3 shows a horizontal section through the furnace according to Fig. 1 taken through the shaft of the furnace and seen downwards. Fig. 4 shows a diametrical section through the lower part of the oven. Fig. 5 shows a section on a stone scale along the line 5-5 in Fig. 4 in the direction of the arrows. Fig. 6 is a sectional view taken along line 6-6 of Figs. 4 and 5 in the direction of the arrows. Fig. 7 is a side view of a part of the oven according to Fig. 2 seen from the right side. Fig. 8 shows a detail of the dome furnace.

Sasom framgar av ritningarna, Sr kupolugnen enligt foreliggande uppfinning forsedd med ett eldfast foder 1 (se fig. 2 och 4), vilket lampligen innehaller partiklar av kol. Ugnen muras in med delta foder till en niva av hogst cirka en meter ovanfor formnivan, se 1 i fig. 2. Ovanfor denna nivA kan man anvanda nagot annat inmurningsmaterial, da temperaturen p5 grund av de for uppfinningen karakteristiska driftforhallandena blir relativt lag Mom denna del av ugnen. Del Sr Sven mojligt att helt utesluta fodret i ugnens Ovre del och kora pa sjalva platmanteln 61, da denna genom den utvandiga kylningen skyddas for starka pakanningar. En sadan utforingsform antydes vid beteckningen 61 till hoger i fig. 2. As can be seen from the drawings, the dome furnace according to the present invention is provided with a refractory liner 1 (see Figs. 2 and 4), which suitably contains particles of carbon. The kiln is walled in with delta lining to a level of logging about one meter above the mold level, see 1 in Fig. 2. Above this level, some other masonry material can be used, as the temperature due to the operating conditions characteristic of the invention becomes relatively low. of the oven. Part It is possible for Sven to completely exclude the lining in the upper part of the oven and run on the plate jacket 61 itself, as this is protected from strong packing by the external cooling. Such an embodiment is indicated by the designation 61 to the right in Fig. 2.

Kupolugnens ovre ande Sr normalt sluten och forsedd med en lamplig ledning for bortledning av gasen. Denna ledning Sr sasom visas i fig. 1 forsedd med en ventil nara kupolugnens topp for uppratthallande av ett konstant gastryck i ugnen. Ventilen kan ocksa placeras p5 nagot avstand nedanfor 5vre an-den. Detta gastryck, som alstras genom den genom formorna tillforda luften och beskickningens mottryck inverkar ph slaggbadets djup. Wining eller minskning av beskickningen Rat- eller minskar darfor endast avtappningshastigheten for slaggen och metallen men har icke flagon inverkan pa slaggbadets djup. Kupolugnen beskickas genom ett par Over varandra liggande luckor vid ugnens dyne ande. I allmanhet bromsas gasstrommen emellertid sa starkt i ugnen, att man utan risk for svangningar i slaggbadets djup kan anvanda enkelt uppsattningsmhl. The upper end of the dome furnace is normally closed and provided with a suitable conduit for the discharge of the gas. This line Sr as shown in Fig. 1 is provided with a valve near the top of the dome furnace for maintaining a constant gas pressure in the furnace. The valve can also be placed at some distance below the upper end. This gas pressure, which is generated by the air supplied through the molds and the back pressure of the mission affects the depth of the slag bath. Wining or reducing the load Steering or therefore only reduces the draining speed of the slag and the metal but does not have a flawed effect on the depth of the slag bath. The dome furnace is loaded through a pair of overlapping hatches at the furnace's duvet spirit. In general, however, the gas stream is braked so strongly in the furnace that it is possible to use simple set-up holes without risk of fluctuations in the depth of the slag bath.

Sasom visas i fig. 2 Sr kupolugnen icke langt frau sin botten forsedd med flera formor, som aro monterade fOrskjutbara i cylindriska studsar 50, sa att de kunna stallas in med mynningen ph ett forutbestamt avstand innanfor fodret 1, lampligen 50-150 mm. Gcnom att formorna straeka sig innanf5r fodret 1, astadkomma de en koncentrerad f5rbranningszon, som Jigger pa avstand fran det eldfasta fodret, sh att forstoringen av detta minskas. Forvarmd luft ledes in i ugnen genom formorna 51 medelst rtir 52, forbundna med en gemensam varmeapparat, som varmes med gas frau ugnen. Formorna 51 aro tatade mot studsarna 50 och roren 52 me-deist asbestsnoren 53. Den koncentrerade forbranningszonen mellan formorna kan vidgas eller dragas samman genom forskjutning av formorna. Sasom tydligt visas i fig. 2 aro formorna 51 mantlade och anslutna till inlopps- och utloppsror for cirkulering av kylvatten. Dessa inlopps- och utloppsrar sta. lampligen i forbindelse med en icke visad behallare placerad ovanfor formorna, sh att kylvattnet star under ett visst tryck och formorna alltid aro fyllda med -vatten. ugnen uppkommande smalt metall och stagg samlas pa ugnsbottnen 2 med metallen underst och flyta, &Isom framgar av fig. 4, genom kanaler i ugnsvaggen, metallen genom den horisontella kanalen 3 alldeles vid bottenplanet och slaggen genom den hogre upp belagna och uppat lutande kanalen 5, till f5rutnamnda sifonanordning 55, Over vilken den kontinuerliga avtappningen sker under mottryck av en pelare av smalta. Ugnsbottnen 2 inter fran kanalens 3 mynning i ugnen ned mot en draneringskanal 4. Da ugnen drives for framstallning av small metall, Sr kanalen 4 igensatt och rinner den smalta metallen ut genom kanalen 3. Denna Sr relativt lang och liar liten diameter, sa att den latt kan sattas igen. Da smaltningen avbrytes, och ugnen tommes pa. metall och slagg genom kanalen 4, stannar emellertid icke flagon me- -- —3 tall eller slagg kvar i ugnen och salter igen kanalen 3, ty bottnen 2 lutar ned mot dd.- neringskanalen 4. Denna oppnas vid avbrott i smaltningen, exempelvis vid nattskift eller (la kupolugnen stalles om fran smaltning till gasgenerering. Den genom kanalen 3 flytande metallen rinner vidare nedfor sifonens 55 lutande botten 36. Slaggen flyter frail ugnen genom den lutande kanalen 5 till sifonen 55 och lagger sig pa den smalta metallen i densamma. Metallen och slaggen tap-pas salunda separat genom kanalerna 3 och 5, men man kan naturligtvis aven anvanda en gemensam tappkanal, ehuru detta forfarande Sr behaftat med vissa olagenheter. As shown in Fig. 2, the dome furnace is not far from its bottom provided with several molds, which are mounted displaceably in cylindrical bounces 50, so that they can be set with the mouth ph a predetermined distance inside the liner 1, suitably 50-150 mm. By extending the molds inside the liner 1, they create a concentrated combustion zone, which is located at a distance from the refractory liner, so that the magnification thereof is reduced. Preheated air is led into the furnace through the molds 51 by means of pipes 52, connected to a common heater, which is heated with gas from the furnace. The molds 51 are attached to the bounces 50 and the tubes 52 by the asbestos cord 53. The concentrated combustion zone between the molds can be widened or contracted by displacing the molds. As clearly shown in Fig. 2, the molds 51 are jacketed and connected to inlet and outlet pipes for circulating cooling water. These inlets and outlets stand. suitable in connection with a container (not shown) placed above the molds, so that the cooling water is under a certain pressure and the molds are always filled with water. the narrow metal and struts arising from the furnace are collected on the furnace bottom 2 with the metal at the bottom and floating, & As can be seen from Fig. 4, through channels in the furnace cradle, the metal through the horizontal channel 3 right at the bottom to the aforementioned siphon device 55, over which the continuous draining takes place under back pressure of a column of narrow. The furnace bottom 2 is inter from the mouth of the duct 3 in the furnace down to a drainage duct 4. As the furnace is driven to produce small metal, the duct 4 is clogged and the narrow metal flows out through the duct 3. This is relatively long and has a small diameter, so that it can be easily set again. Then the melting is stopped, and the oven is emptied. metal and slag through the channel 4, however, flake metal or slag does not remain in the furnace and salts again in the channel 3, because the bottom 2 slopes down towards the dd. night shift or (let the dome furnace be converted from smelting to gas generation. The metal flowing through the channel 3 flows further down the sloping bottom 36 of the siphon 55. The slag flows from the furnace through the sloping channel 5 to the siphon 55 and settles on the molten metal therein. and the slag is thus tapped separately through the channels 3 and 5, but it is of course also possible to use a common tapping channel, although this method is fraught with certain irregularities.

Sifonen 55 Sr forsedd med en i huvudsak central skiljevagg 56 placerad mellan tapprannan 30 for den smalta metallen och tapprannan 6 for slaggen. Sasom framgar av fig. 4-6, Sr skiljevaggen 56 forsedd med ett hal 32, placerat lagre an kanalen 3 vid nedre kanten av den lutande bottnen 36, sa att den smalta metallen ledes till den uppatriktade kanalen 33, som star i forbindelse med tapprannan 30. I forlfingningen av kanalen 32 ar i sifonvaggen en normalt tilltappt reserviippning 34, genom vilken man vid behov kan rensa kanalen 32. Sifonens 55 oversida tackes med ett lock, som Sr valvformigt och for-sett med en oppen, framre ande, sa att det bildas ett utrymme 41, genom vilket slaggen star i forbindelse med den omgivande atmosfaren. Ocksa den smalta metallen star i forbindelse med den omgivande atmosfaren, namligen vid tapprannan 30. Sifonens 55 framsida fir forsedd med ett par hal 31 och 35, som tackas av en losbar lucka 37 monterad pa en frontplatta 40, vilken tacker kamniarens 55 hela framsida med undantag for utrymmet 41 och oppningen 39 omedelbart nedanfor detta. Oppningen 39 ãr belagen i linje med tapphalet 5, sd att en genom oppningen 39 inford stang kan anvandas for rensning av tapphalet 5 vid be-hey. Halet 31 ligger mitt for tapphalet 3, sd att detta kan rensas vid behov. Hela sifonen 55 kan tOmmas genom halet 35. Sifonen ar pa oversidan forsedd med en oppning 7, som star i forbindelse med sifonens inre, sasom visas i fig. 2 och 4, for en oljebranDare 57 for upphettning av slaggen i sifonen 55. Plattan 40 kan monteras losbart pa sifonen 55 medelst slitsar, genom vilka perforerade oron stracka sig. Genom dessa aro dragna kilar 58 (fig. 2) for kvarhallande av plat-tan 40. The siphon 55 is provided with a substantially central partition 56 located between the tap 30 for the narrow metal and the tap 6 for the slag. As can be seen from Figs. 4-6, the partition 56 is provided with a slide 32, placed lower on the channel 3 at the lower edge of the inclined bottom 36, so that the narrow metal is led to the upwardly directed channel 33, which is connected to the tap. 30. In the extension of the channel 32 in the siphon wall there is a normally tapped reserve opening 34, through which the channel 32 can be cleaned if necessary. a space 41 is formed, through which the slag communicates with the surrounding atmosphere. The narrow metal also communicates with the surrounding atmosphere, namely at the tap 30. The front of the siphon 55 is provided with a pair of halves 31 and 35, which are thanked by a detachable door 37 mounted on a front plate 40, which thanks the entire front of the cam 55 with except for the space 41 and the opening 39 immediately below it. The opening 39 is coated in line with the pin tail 5, so that a rod inserted through the opening 39 can be used for cleaning the pin tail 5 during operation. The tail 31 is located in front of the pin tail 3, so that this can be cleaned if necessary. The entire siphon 55 can be emptied through the tail 35. The siphon is provided on the upper side with an opening 7, which communicates with the interior of the siphon, as shown in Figs. 2 and 4, for an oil burner 57 for heating the slag in the siphon 55. The plate 40 can be releasably mounted on the siphon 55 by means of slots through which perforated ropes extend. Wedges 58 (Fig. 2) are drawn through these to retain the plate 40.

Kupolugnen kyles Over hela sin utsida me-deist en sarskild kylanordning. Denna omfattar ett perforerat ror 60 placerat runt ugnsmantelns ovre ande, sasom visas i fig. 1. Roret star i forbindelse med nagon kalla for kylvatten, sa att detta kan sprutas fran halen i roret 60 mot ugnens utsida och nedfor denna. Omkring ugnsvaggen Sr i jamn hojd med slaggrannan 6 och omedelbart nedanfor formorna anordnad en ranna 19, som samlar upp det kylvatten, vilket strommar nedfOr ugnens utsida fran rbret 60. Ett par avloppsror 20 och 21 aro anslutna till rannans 19 botten och leda vattnet frail rannan till en andra ranna 16 anordnad runt ugnen vid dess hotten. Omedelbart nedanfor rannan 19 finnes ett andra perforerat ror 28, som stracker sig runt ugnen utom dar sifonen 55 ar forenad med ugnskroppen. Floret 28 kan std i farbindelse med samma kalla for vatten som roret 60. Det fran det perforerade roret 28 kommande vattnet rinner nedfor ugnens utsida mellan rannorna 19 och 16 samt samlas upp i den senare. The dome furnace is cooled All over its outside with a special cooling device. This comprises a perforated tube 60 placed around the upper end of the furnace jacket, as shown in Fig. 1. The tube is connected to some cold cooling water, so that this can be sprayed from the tail of the tube 60 towards the outside of the furnace and below it. Around the furnace cradle Sr at a level with the slag hose 6 and immediately below the molds a gutter 19 is arranged, which collects the cooling water, which flows down the outside of the furnace from the pipe 60. A pair of drain pipes 20 and 21 are connected to the bottom of the gutter 19 and lead the water from the gutter to a second gutter 16 arranged around the furnace at its hood. Immediately below the rim 19 is a second perforated tube 28, which extends around the furnace except where the siphon 55 is joined to the furnace body. The flute 28 can be connected to the same cold water as the pipe 60. The water coming from the perforated pipe 28 flows down the outside of the furnace between the gutters 19 and 16 and is collected in the latter.

Sasom visas i fig. 4, stracker sig rannan 19 runt ugnskroppen mellan denna och sifonens 55 ovre del, sa att vattnet i rannan 19 ocksa kyler ovre delen av sifonen liksom den intilliggande delen av ugnen. As shown in Fig. 4, the gutter 19 extends around the furnace body between this and the upper part of the siphon 55, so that the water in the gutter 19 also cools the upper part of the siphon as well as the adjacent part of the oven.

Sasom framgar tydligast av fig. 5, ar skiljevaggen 56 i sifonen f8rsedd med en urtagning 42. Sasom framgar tydligast av fig. 2, star en ledning 22 i forbindelse med rannan 19 och mynnar mot sifonvaggen ovanfOr denna urtagning 42, sa att vatten fran rannan 19 strommar till urtagningen 42, fyller denna och rinner ned utefter sifonens 55 utsida. Sasom visas i fig. 2 och 3 stracker sig en lutande plat 29 fran urtagningen 42 till rannan 16, sa att vattnet i denna hindras fran att stanka pa metallen i tapprannan 30. As can be seen most clearly from Fig. 5, the partition 56 in the siphon is provided with a recess 42. As can be seen most clearly from Fig. 2, a conduit 22 stands in connection with the gutter 19 and opens towards the siphon cradle above this recess 42, so that water from the gutter 19 flows to the recess 42, fills it and flows down along the outside of the siphon 55. As shown in Figs. 2 and 3, an inclined plate 29 extends from the recess 42 to the gutter 16, so that the water therein is prevented from stinking on the metal in the gutter 30.

Speciella atgarder aro vidtagna for att kyla vaggen pa utsidan av forbindelsen mellan sifonen 55 och ugnen, sasom visas i fig. 3 och 8. For detta andamal har man anordnat ett par platar 25 och 26 med samma krokfling som denna vagg. Platarna stracka sig nedat fran rannans 19 undersida och folja ugnens vaggar vid denna forbindelse. Rannan 19 Sr i bottnen forsedd med ett par slitsar 23 och 24, som ha samma krakning som platama 25 och 26 och mynna innanfor dessa, sa att vattnet frail rannan 19 kommer att stromma genom de smala mellanrummen mellan platarna 25 och 26 och forbindelsevaggarna. Harigenom kylas dessa, sâ att for starka spanningar och sprickbildning vid dessa vanligtvis svaga punkter i ugnskonstruktionen forebyggas. Special steps are taken to cool the cradle on the outside of the connection between the siphon 55 and the oven, as shown in Figs. 3 and 8. For this purpose, a pair of plates 25 and 26 with the same hook flap as this cradle have been provided. The plates extend downwards from the underside of the gutter 19 and follow the cradles of the oven at this connection. The channel 19 Sr at the bottom is provided with a pair of slots 23 and 24, which have the same cracking as the plates 25 and 26 and open inside them, so that the water frail the channel 19 will flow through the narrow spaces between the plates 25 and 26 and the connecting cradles. As a result, these are cooled, so that excessive stresses and cracking at these usually weak points in the furnace construction are prevented.

Pa den av sifonens 55 sidovaggar, dar slaggavtappning sker, Or en lada 9 monterad, till vilken kylvatten ledes genom ett rot. 8. Ladan Sr byggd i anslutning till slaggtappningsrannan 6 pa sa salt, att den till dels omsluter den fran denna ranna gaende Ovre bottnen 11' i en uppat oppen kanal 10 med en undre botten 11". Ladan 9 kommunicerar med det mellan bottnarna 11' och 11" bildade mellanrummet 13, genom vilket vattnet alas& kan rinna fran ladan 9 nedfor kanalen 10 utefter bottnen 11". Slagg kommande fran tapprannan 6 och rinnande nedf8r 4— — bottnen 11' maste salunda rinna ut over och komma i kontakt med det kylvatten, som rinner nedfor kanalens 10 botten 11" fran mellanrummet 13, sa att den granuleras. Slaggen rinner tillsammans med vattnet nedfor kanalen 10, som mynnar i ett nedatriktat ror 14, vars ovre ande är sluten. Vattnet och slaggen runner nedfOr roret 14 till en nedanfor ugnen anordnad grop. Roret 14 har i niva med rannan 16 en oppning, i vilken en kanal 17 med lutande botten 18 mynnar. Denna star i forbindelse med en utvidgning 15 av rannan 16, sâ att vattnet fran rannan 16 forenas med vattnet och slaggen fran kanalen 10 i 1.1:Vet 14 for att rinna ned i uppsamlingsgropen. On the one of the side cradles of the siphon 55, where slag draining takes place, a barn 9 is mounted, to which cooling water is led through a root. 8. The barn Sr is built in connection with the slag draining channel 6 on so salt that it partly encloses the upper bottom 11 'extending from this narrow channel in an upwardly open channel 10 with a lower bottom 11 ". The barn 9 communicates with it between the bottoms 11' and 11 "formed the space 13, through which the water is blown & can flow from the barn 9 down the channel 10 along the bottom 11". , which flows down the bottom 11 "of the channel 10" from the gap 13, so that it is granulated. The slag flows together with the water down the channel 10, which opens into a downwardly directed rudder 14, the upper spirit of which is closed. The water and slag run down the pipe 14 to a pit arranged below the furnace. The rudder 14 has an opening at the level of the gutter 16, in which a channel 17 with a sloping bottom 18 opens. This is in connection with an extension 15 of the gutter 16, so that the water from the gutter 16 is combined with the water and the slag from the channel 10 in 1.1: Vet 14 to run down into the collecting pit.

Sasom framgar av det foregaende, beskickas ugnen enligt uppfinningen alltid med ett sadant overskott av kol i forhallande till syre, som tillfores med luften, och syre, som är bundet i form av reducerbara oxider i beskickningen, att en starkt reducerande gas er- Branslemangden i beskickningen uppgar salunda till cirka 15-25 % mot normalt cirka 10 %. Enligt uppfinningen ser man salunda hart Iran bransieforbrukningen och inriktar sig pa att astadkomma reducerande atmosfar och hog temperatur i ugnen. Denna storre bransleforbrukning kompenseras emellertid av flera fordelar. Salunda kan beskieliningen i sin helhet goras billigare, da man kan anvanda ett mycket billigt metallmaterial, sasom skrot av stal och gjutjam. Reparationskostnaderna liksom aNen forlusterna genom stillestand far reparation bli avsevart mindre an vid vanliga kupolugnar. Vidare producerar ugnen stora mangder energirik generatorgas med en kolmonoxidhalt av cirka 25 %. En berakning av ugnens varmebalans visar i ett sarskilt fall, att av tillforda 100 kalorier i form av koks forbrukas 26,5 for smaltningen av metallen, 54 for gasgenerering, 1,5 genom forluster till slaggen, 10,5 genom varmeforlust till kylvattnet och 7,5 till forvarmning av blasterluften. Med hansyn till de bildade anvandbara produkterna kan kupolugnen enligt uppfinningen sagas utgora en kombination av en kupolugn och en gasgenerator. As can be seen from the foregoing, the furnace according to the invention is always charged with such an excess of carbon in relation to oxygen supplied with the air, and oxygen, which is bound in the form of reducible oxides in the charge, that a greatly reducing gas is produced. the mission thus amounts to about 15-25% against normally about 10%. According to the invention, Iran's fuel consumption is closely monitored and focuses on achieving a reducing atmosphere and high temperature in the furnace. However, this greater fuel consumption is offset by several benefits. Salunda can in its entirety be made cheaper, as you can use a very cheap metal material, such as scrap of steel and cast iron. The repair costs as well as the losses due to downtime, repair may be considerably less than with ordinary dome stoves. Furthermore, the furnace produces large amounts of energy-rich generator gas with a carbon monoxide content of approximately 25%. A calculation of the furnace's heat balance shows in a special case that of the added 100 calories in the form of coke, 26.5 are consumed for the smelting of the metal, 54 for gas generation, 1.5 by losses to the slag, 10.5 by heat loss to the cooling water and 7 , 5 for preheating the blaster air. In view of the usable products formed, the dome furnace according to the invention can be said to constitute a combination of a dome furnace and a gas generator.

Den erforderliga mangden bransle varierar aven med arten av det uppsatta metallmaterialet. Om detta till 100 % bestar av tack- jam, fordras salunda 11koks med en ask- halt av % och 24 % koks med samma askhalt, om metallmaterialet till 100 % be-star av stalskrot. The amount of industry required also varies with the nature of the set metal material. If this consists 100% of tack jam, 11 coke with an ash content of% and 24% coke with the same ash content is required, if the metal material consists 100% of steel scrap.

Sasom tidigare har namnts, anvander man fOrvarmd blasterluft med en temperatur av cirka 400-600° C. Varmet for denna forvarmning erhalles genom varmevaxling med en gas erhallen genom forbranning av en del av generatorgasen. For att erhalla avsedd blasterhastighet satter man vidare blasterluften under hogre tryck an normalt. Vid en ugn med en kapacitet av 2 ton small metall per timme komprimeras blasterluften &Panda med ett tryck av cirka 60 cm vp mot nor-malt cirka 25 cm vp yid vanliga kupolugnar. Vidare utforas formorna vid ugnen med vasentligt mindre sammanlagd tvarsnittsarea i forhallande till ugnens invandiga tvarsnittsarea i samma niva an vid vanliga kupolugnar, I vilka forhallandet mellan ugnens area och formornas sammanlagda area ligger vid cirka 5-10, medan det ligger Over 12 vid ugnen enligt uppfinningen. Harigenom kommer blasterluften att blasas in med vasentligt stOrre hastighet da normalt, namligen med cirka 80-100 m/s. Genom denna hoga inblasningshastighet och den ringa formarean erhalles en starkt koncentrerad zon for forbranning av bra.nslet, dar temperaturen blir mycket hog, cirka 1800° C, och kan drivas upp till cirka 2000° C. Denna on ligger ett stycke innanfor ugnens insida, eftersom formorna aro inskjutna och luften biases in med hog hastighet, sa att ugnens fader skyddas. Redan ett kort stycke ovanfor denna hogtemperaturzon sjunker emellertid temperaturen till cirka 800° C for att vid toppavloppet fik gasen vara nere under cirka 500° C. I hogtemperaturzonen forbrannes kolet snabbt till koldioxid, som redan nagra centimeter ovanfor for-mama reagerar med kol till bildning av kolmonoxid. En starkt reducerande miljo kommer salunda att rada i byre delen av hogtemperaturzonen. As previously mentioned, preheated blaster air with a temperature of about 400-600 ° C is used. The heat for this preheating is obtained by heat exchange with a gas obtained by burning a part of the generator gas. In order to obtain the intended blaster speed, the blaster air is further set at a higher pressure than normal. In an oven with a capacity of 2 tons of small metal per hour, the blaster air & Panda are compressed with a pressure of about 60 cm vp against the normal about 25 cm vp yid ordinary dome furnaces. Furthermore, the molds at the furnace are made with a substantially smaller total cross-sectional area in relation to the internal cross-sectional area of the furnace at the same level as with ordinary dome furnaces, in which the ratio between the furnace area and the total area of the molds is about 5-10. . As a result, the blaster air will be blown in at a significantly higher speed than normal, namely at about 80-100 m / s. Due to this high blowing speed and the small mold area, a highly concentrated zone for combustion of the well is obtained, where the temperature becomes very high, about 1800 ° C, and can be operated up to about 2000 ° C. since the molds are inserted and the air is biased in at high speed, so that the furnace father is protected. However, already a short distance above this high-temperature zone, the temperature drops to about 800 ° C so that at the top drain the gas is allowed to be below about 500 ° C. of carbon monoxide. A strongly reducing environment will thus line the upper part of the high-temperature zone.

I denna starkt reducerande hogtemperaturzon Aga de metallurgiska reaktionerna rum mycket snabbt. Salunda reduceras i beskickningen ingaende oxider, sasom rost och eventuellt maim, till motsvarande metaller saint smaltes den i koksen ingaende askan och forenas med tillsatta slaggbildningsmedel, sasom kalk, till en basisk och svarsinalt slagg, som är i huvudsak fri fran jarnoxid och I vikt raknat lampligen innehaller cirka 1,41,5 ganger sa. mycket CaO som Si02. Slaggen far samlas till ett cirka 300 mm djupt och pa smalt metall flytande slaggbad i ugnens nedre del. Genom detta bad passerar den smalta metallen i form av droppar, som under passagen genom badet reagera med detta, exempelvis avsvavlas genom bindning av svavlet i den basiska slaggen. Eftersom dessa reaktioner forlopa relativt langsamt och reaktionsgraden i viss man beror pa. langden av den tid, under vilken metalldropparna aro I kontakt med slaggen, är det, om man Ons- hammetall as jamn kvalitet, myc- ket viktigt att hâlla slaggbadets djup konstant. In this strongly reducing high temperature zone, the metallurgical reactions take place very quickly. Salunda inhaled oxides, such as rust and possibly maim, are thus reduced to the corresponding metals, the ash contained in the coke is melted and combined with added slag-forming agents, such as lime, to a basic and refractory slag, which is substantially free of iron oxide and aptly contains about 1,41.5 times said. much CaO as SiO2. The slag may be collected in an approximately 300 mm deep and on a narrow metal liquid slag bath in the lower part of the furnace. Through this bath, the molten metal passes in the form of droplets, which during the passage through the bath react with it, for example desulfurized by bonding the sulfur in the basic slag. Because these reactions proceed relatively slowly and the degree of reaction to some extent depends on. The length of time during which the metal droplets are in contact with the slag, it is very important, if the uniform quality of Onshammetall as, to keep the depth of the slag bath constant.

En. annan viktig foljd av den reducerande atmosfaren vid hog temperatur ar, att i beskiekningen ingaende kisel, exempelvis i form av ferrokisel, icke oxideras och upptages i slaggen utan loses i metallen, sa att denna far avsedd kiselhalt. Man kan ocksa. genom — — hOjning av temperaturen uppna en reduce-ring av kiseldioxid, som ingar i beskickningen, sä att metallen far hagre kiselhalt an som svarar mot mangden i jarnbeskickningen ingaende kisel. One. Another important consequence of the reducing atmosphere at high temperatures is that the silicon contained in the coating, for example in the form of ferro-silicon, is not oxidized and taken up in the slag but is dissolved in the metal, so that it has the intended silicon content. You can too. by raising the temperature, a reduction of silica, which enters the charge, so that the metal has a better silicon content which corresponds to the amount of silicon contained in the iron charge.

Slaggens jarnhalt blir alltid mycket lag, aven om beskickningen innehaller storre mangder jarnoxider, sasom rost och liknande, och ligger sallan over 0,8 %. The iron content of the slag is always very low, even if the embankment contains larger amounts of iron oxides, such as rust and the like, and the salt is above 0.8%.

Om smaltningen i ugnen skall stoppas fOr en kortare tid, exempelvis over ett nattskift, tappar man ut slagg och metall genom draneringshalet 4, sa att icke nagon metall eller slagg kan stelna i kanalerna 3 och 5 och satta igen dem. Onskar man driva ugnen en-hart for generering av gas, beskickar man ugnen med endast bransle och tappar den da bildade slaggen genom halet 4, varvid kanalerna 3 och 5 lampligen proppas med sand e. d. If the melting in the furnace is to be stopped for a short time, for example over a night shift, slag and metal are drained through the drainage tail 4, so that no metal or slag can solidify in the channels 3 and 5 and clog them. If you want to drive the furnace solely for the generation of gas, you load the furnace with only fuel and drop the then formed slag through the tail 4, whereby the channels 3 and 5 are suitably plugged with sand and the like.

Claims

Attention:

1. Set to produce in a dome furnace cast iron or tack iron of any oxide-containing iron material, characterized by the combination of (a) that the furnace is loaded with the iron material and fuel in such an initial surplus in proportion to the quantity required to achieve the desired furnace temperature and for carbonization of steel scrap and any reduction of metal oxides and silicon oxides which may not be present in the charge, that an atmosphere reducing iron oxide is obtained in the shaft, (b) that basic slag formers are added in such an amount that the formed slag becomes alkaline, (c) that the furnace the outside is cooled with water, (d) the blaster is preheated to a temperature of about 400-600 ° C and (e) is blown in at a speed of Over 80 m / sec, (f) through water-cooled molds, (g) which forms a essential piece inside the inner cradle of the furnace and (h) that narrow metal and slag are continuously drained at the bottom of the furnace in such a way that a substantially constant slag depth is maintained in the dome furnace.

2. A kit according to claim 1, characterized in that the blaster is blown in at a speed of about 100 m / sec. 400-600 ° C, a device for blowing the preheated blaster through a number of water-cooled molds (51), the mouth of which jigs a substantial piece inside the inside of the oven cradle, the molds having such a total cross-sectional area in relation to the blowing device of the oven warning conditional capacity, that the preheated biaser is blown in at a speed of Over 80 m / sec, and the furnace is provided with a device (60) for cooling its outside with water and with one or more tapping halls for continuous tapping of metal! ( 3) and slag (5), which result in a siphon device (55) for the metal and the slag, so that a constant slag depth in the furnace is achieved. entanspraket 3, characterized by the fact that the upper part of the furnace, razed from a level just above the molds, consists of a plate jacket (61) without a father. Furnace installation according to patent claim 3 or 4, characterized in that the lining (1) in the lower part of the furnace consists of carbonaceous, acidic stamping compound. Furnace installation according to claim 3, 4 or 5, characterized in that the furnace bottom (2) is inclined from the tapping hole (3, 5) towards a drainage hall (4) for emptying the furnace of metal and slag. Stockholm 196

3. KunO. Boktr. P. A. Norstedt & Saner. 630089 Pl. I. THE GENERAL STAFF