CA2063711A1 - Method and apparatus for heating a metallurgical furnace - Google Patents
Method and apparatus for heating a metallurgical furnaceInfo
- Publication number
- CA2063711A1 CA2063711A1 CA 2063711 CA2063711A CA2063711A1 CA 2063711 A1 CA2063711 A1 CA 2063711A1 CA 2063711 CA2063711 CA 2063711 CA 2063711 A CA2063711 A CA 2063711A CA 2063711 A1 CA2063711 A1 CA 2063711A1
- Authority
- CA
- Canada
- Prior art keywords
- fact
- burner
- oxygen
- fuel
- furnace
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23K—FEEDING FUEL TO COMBUSTION APPARATUS
- F23K3/00—Feeding or distributing of lump or pulverulent fuel to combustion apparatus
- F23K3/02—Pneumatic feeding arrangements, i.e. by air blast
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/52—Manufacture of steel in electric furnaces
- C21C5/5211—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace
- C21C5/5217—Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace equipped with burners or devices for injecting gas, i.e. oxygen, or pulverulent materials into the furnace
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D1/00—Burners for combustion of pulverulent fuel
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D2900/00—Special features of, or arrangements for burners using fluid fuels or solid fuels suspended in a carrier gas
- F23D2900/00006—Liquid fuel burners using pure oxygen or O2-enriched air as oxidant
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Abstract
Described is a process for heating a metallurgical furnace, in particular an arc furnace charged with scrap metal or a similar solid material. Oxygen and fuel are fed in through the furnace wall by at least one burner located above the melt, the fuel being supplied in a carrier-gas stream which completely surrounds the oxygen feed line. The process is particularly cost-effective owing to the fact that 4-15 kg/t of coal dust of particle size <200 µm in an inert-to-slightly reducing carrier gas is used as the fuel, being fed in at a speed of at least 45 m/s, at least while the charge is melting, and being burnt in a diffuse flame in stoichiometric to slightly greater than stoichiometric proportions in oxygen emerging from the burner at about the speed of sound and at a pressure of at least about 1 bar. Also described is a burner particularly suitable for use in this process.
Description
2~7~ :
9~ 57 ~ I ''I -' '~7~ 54~'7 COHEN P~IIITRIII ~2 METlIOD ANl~ Al'PAT~A'l US YOR HEATlNC A METALLuR('7lcAL FURNACE
Thc presen~ invenliol~ relates t~) a metl)od of hea~ g a tl~etallurgical furnace, in particular an electric arc furnace char~ed willl scrap or simila.r solid m~terials. Ivletllods of this type ale nIlmero~ls ~nd have been kno\vn for a long ~in~e and new olles are bcing cons~an~ly propose(i. Thus, for instance, in F`ederal Republic of C3ermany P~lellt 14 33 424 a melting fllrnace is described w hicll can be optionally healed witll burners and electro(les, oxy~en ;~n~ ow~k.r~.fl fll(~.lc ~ in(rl~ ,c~l vi,~ Ihe l~ .rs. I-iow~vel. Iultllel details concerllill~ Ille l~urner he~ling are not given in ~llc patcll~. Frcqllcnlly, exclusively ~as or oil :: burllers arc clllployed in S~lCtl methods, as for installce in ~hc mctllod in accordance with l~e~Jeral Republic of Gcrlnany 25 41 0P~6.
.~~P-A-O 200 ~0~ ~Ic~-:rlt~s ~ UU ur ~ ur~ rurn~ tn which ~owdered coal of a particlc sizc Or 4.S ~m and an approxima~ely .stoicl-iollletl-ic 4uanllty of oxy~,en is fe~l tllro~lgll a burner. ln this case, the fuel, th.lt is the coal, is fed by a .5~ream of vehicle ~as whicll sLIrlollllds tlle inller oxygell cha-lllel allnlllarly. Finally, such a me~ho~l is i~lso knowll from EP^i~ 4 ~78, carbon of a ~i7.e less thal- 10 /ln- being fed by mc~lls of an inerl slream of vehicle gas.
The objecl of the preseni in\~entioll is to iml.lroYc thc prior art by a ncw metllod so that thc heating and melling c~all be carrie~l Oul reliably all(l ecollolllically an~l to ill(licate ~n apparalus wl~ic~l is l~r~icularly sui~ble rOr IhiS p~lrpoSe. ]`or thiS purpose 4 to 15 I>f po~ ert ll coal of a particle sizc of ~ ''00 ~m per lon of 1i4uid melal produced is red in an inerl to sli~htly reducillg Yclliclc gas witll a veloci~y Or al leasl 4~5 m/second at lea.s~
124~119.1~C'I' .
~ ' . '. :,~ -. : :, :
.- - ` , ~: ~ ` . : : ' - 2~37l1 ' 9 2 ~ 5 7 ;!: 1 2 1 2 9 7 2 5 ~ ~: 7 I, o H E l l P :: I I T ~ 3 d~uing the melting down nf the c~argc and is burned witl~ form~liol) of a ~liffuse ~lame"
stoichiomelrically lo s]ightly al)ove stoichiomelrically l~y oxy en lo~r~ing from Ihc burl)er a~
the spe~d ~f su~lnd and a pre.jsur~ Or a~ si nne ~ar.
With this new loethod all types of steel ~nd ferro-alloys lS we]l as s~lit~ble noll-ferroos melals can be treat~d. An increase in output of abo~lt ]0"~o as wcll as a redllclion in the fecd of electric ener~y by abollt 5~ KWh/t can be oblailled alleady wilh av~rage amollnt.j of chargc.
Advanla~eolls en)bodil~ s Or ~lle invel)tion arc indicated in Ihc other Inetl-odclairns. lt has sllrl~risin~ly been fo~ d th~t as comparcd wi~h the preViO~ls~y known methods of operalit)ll considerable improve1ncllts in tl~e resull of the operatioll can ~e ob~ained by the use of the methnd nf thc present invenliOIl~ In this conn~clioll the paramelers of tllc method were prefer~bly so selected th~t ~I)e pressure of ~he emergillg oxygen is al leas~ 0. ~ bar above ;: ~he intcrllal pressllre prevailillg withill ~he rurnacc that tl-~ p~)~vdered coal is fed in amoullts of S to 10 I;g/t of liquid mct~l produ~ed ~h.l Il~e velocity of Ihe vehic]e gas is at ~e;~sl ~0 ~ ~ -M/second and that the pressure in tl~e oxygen line (pre-pressure) is adj~lste-l to 12 In 16 bar ~-and pr~fera~)ly 13 to 15 bar. l~he fucl ~Ised is preferal)]y a po~v~ler~l co~l con~ail~ 8 ~o l 5 % vo]~lile colnpollents ~:
If it is intell(led l~l add the SCl;1p b.llch-~Yise fnr insl~nCe in c~lstomary Inanller in the char~in~ c lge it is advant~olls ln s~art the introd~clioll of coill and oxygen wi~hin lwo minlltes after thè charging. This inlr( d~lction is ~.dv~n~ageously conlinued for a pèriod of 9 ~o 17 minutes d~lrin~ a batcb se4ucncc.
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Particularly favor~hle resl~lts ca~ e obtain~d if the raLio of the mass flow of coal to ~hal Or vehicle gas is 10 to 2t) l)pon the chargis~ of the furn lce witll scrap or the like l~y means for inst~llcc of a charging cage, thc l~llrners are preferably ren~o~ed fron~ thc f~rnace, When introduced l~ll nol in th~ir operatin~ phase or phases lhe burners are chalged with a .~icavengin~ ~as preferably air al le~st in the fuel cl~anlle~ orcler lO ~eep lhe channels open 1 h~ qualltity fed amoun~ in this conncction preferah]y IO 170 to 200 lin~'/hr dependin~ on tllc sizc of lhe ~urner.
A j ~pp~ratus for the carrying out ~)f the ~netl~od tl~ere is yrovid~d a bllrner which has a shaf~ formed of ~wo concentlic l~ll)CS, lhe annular ch~nllel thereof discl~arging into a widened annlllar spaCe of ~ distribl~tor holes arranged annularly an~l cohxidlly to the shaft debourhing into thc annular sp~ce frolll the opposi~e side Ihe l`ee~ side ~ait5 holes ~eing connccted n~ their feed side to a fuel con~ an(J hy ~n oxygen feed line conlleclcd lo Ihe oxy~en channel formed by Ihe hlller luhe of ~he sllafl Advanl~geollS developmenl~ of Ihe new burller arc se~ for~h in tl~e 7~lt~ched apparal~ls clail~
rhe method of the invenlion and the app~ratl,s for the calrying out of Ihe lhod will be explained in fllrlher delail with reference to the drawillgs eacl~ of which shows onc elnhodin~ent of the metllod and lhe as~par~lus ln lhe dr.lwing:
I`ig I is ~ diagral7~ of a plan f~)r lhe fee~ing of n~terial to all arc furllace.
Fi~ 2 is a diagrammatic hori~ontal sèc~ion tllrougll the arc f~rnace of l~ig. 1.
Fi~ ~ is an Ou~pllt cllrve of a bllrner.
., .
; -3-2~7 l~
..-.,, 02 1 I: 5g ~ 1 2 1 2 972 54~7 CrJHEII P01ITRNI ~5 '.
~ig. 4 shows the main piece of a burner half in outer view and half in klngitudinal sectic~n.
~s shown in the diagr~m of l ig 1, in Ihc case of an ele~tric arc furnace I
having three e]ectr/)dcs ~ lwo burllers are inlroduc~ rou~h tl~e walel-cooled ~urnacc wall c~n ~hc si~e al)o\e the melt Eacll of ~ wo ~)urners ~ and 4 has a pressule conveyor 5 each provided with a weighing device ass~)ciated wiih it ~he pressurc conYeyors ~ bcing ~upylie~l fron~ a stora~e bin 6 with powdered coal which i~ possibly c~assified in an interposed screenin~ d~vice 7 The coal withdrawn Irol~ tlle press~lre conv~yors 5 i5 ïed lo Ihc burners 3 and 4 via cunduits 8 wilh nitr(lgell flol-- ia sn~lrce of ni~ro~cn nol showll The fe~din~ of oxyg~n to lhe bl~rner~ 3 and 4 is effecled Vi;1 ~wo conduils g. rlle furnace ] is furtllermore provided with A known device 10 for determinillg the cxllalJs~-~As analysis whicll is used to regulate the mass flows fe~ lo the burners wilh dlle consideralioll als~- of tl)e efficiency, reterred to dirfcrellt typeS and Cl)lllpO!;itiOlls of coal The amoull~ of tlue gas is in lhis conncctio1l nlcasllred by the knowll He-tracer mctho(l usill~ d ~ilreaI11 of helium wl-ich is introduced illtO the furndce.
Fig. 4 shows the constrl~cli- n of ~he burners: Adjoining a shAt`t l~l which consists of lwo concentric tutles l l ~nd 12 and can be displa(:ed lo~ udillally into the furll~ce, ~here is the ~lclual parl of the burncr a ~listribu~or 14 formed of scveral parts of rotational sylnmetry Thc annular Cll~nlle] 1S de~cloped betweell tl~e two ~u~es 1l al-d l2 debouches in~o a widen~d annular space 16 of lhc di~lribulor 14. J rom the opposile side namely tlle feed sid~ f~c~llg aw~y from ~hc anl1ular cl~anncl l.~, six ho]es 17 whicll are arranged annlllarly an(l coaxial lo the shaft 13 ~lèhollch into ~he anlllllar space 16"he holes N~ Sl I 9.1~ 4-,; .
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2~63711 ' ~2 e~ 2 1 1: 5'3 7 1 2 1 2 972 5487 COHE~I PONTf:llJ I ~G
bcill~ conl)ected on the feed si(ie lo a cylindrical collection space l8 A fllel conduit 8 for lhe feeding of the coal is flange(l onto ~he cnd ~ f ~l~e collcction s~ace i ~ coaxial lo tl-e di~triblltor 14 ~he condl)it 9 for the fe~rling of oxy&en is c~nnected (o ~ll anlllllar collection space 19 which sullounds a po~-sl~aped sLlpport melllber 20 witl-in which the holcs 17 are arrall~ed Tlle collection space 19 is connecte~l via six radial c)l~nnels I ex(ending in ~ach case be~ween the holes 17 to the o ~y~en ~llallnel 22 tormed l~y tlle inner l~be 12 -, Tllc ann~llar space 16 is forl~cd by ~ in~,erlioll of a snit~hly sllaped inseltion member 2~ in s~lch ~l mallller Ihal ~he gr~test part of i~s inller wall wi~lens to\~/ards ~he holes - ]7 so that the Idr~,cst diam~ter of thc inner wall agrees Willl tlle ~mallest diameter, nalllely ~he corc diarnelcr, of the circle or holes 17 ~n lhc oppusite side, the ann~llar space l ~
rorn~s an end surface 24 All parts of the ~listribu~or 14 are pllshe~J one on Ihe other and fastened to each other by flange collllectiol~s so Ihat simple assemhljllg and taking aparl of lhe bllrner is possib~e rhe deve~opmen~ of tl~e (li~lrib~ltor 14 in accordance witll the invenlion fur~hermore results in ~he a~lvant~ge Or only sli~llt weilr of tlle parts condllclil-g the po~dere~l coal ~elween the colleclion space 18 all~ lhe fuel condllit 8, a b~ffle plate 27 - havin~ ~hrce openill~,s 28 is provided as ~low distriblltol, it retardill~ ~he str~ Or vellicle ~as laden ~vith coal dust and dividing it into lllree individnal streams The ol~enil)gs 28 are ; ~ so arranged Ihdl cacll Or lhe three indiVid~lal streallls is ~listribll~ecl over ~,vo of Ihc six holes 17, in which it is f~rlhcr decelcrate~l Acceleration lakes pl~ce again only al the transition into the annl~lar ch,tnnel IS By lhis conslruc~ of tlle nozzle, ~llc wear of the distributor 14 by abrasion is still fllrther reduced Nl~lJ~llV,I'I.`'I' 5 .
2~71~
' g2 13 1 ~12 1 2: 0~1 2; 1 2 1 2 ~2 5~ 7 COHEiJ ~nNTn\~ 7 '. .
ILl~usTRA~lyE EJ~ oOlMEl~T
I`he method of the invenîioll was ~l~ed on a 140-t~UHP electric arc fl~rnace, ~he ~rrallg~ment shown in Fig, I being llsed. Tl~e ~wo t)urllt~rs ~ ~nd 4 wcre jo ~rr~ hal the one burncr 3 ex~ lc~ acl(cct thr~ ugl~ tho 51n6 dool r)S, int~ )r fl)rl~c~ 1 alld the other t urner 4 was inserted ~hro~gh lhe fllrnace wall 90G away rrol~ )c burncr ~ lhrollglI a sui~able opening, as cal~ be noted from I~i~,. 2. 1~ c~n r~lrll~ermore bt! noted froll- Fig. 2 lhat - ~
tl)~ burner 4 is directed in the so-calied "cold s~ot" rcgiol~ 26 be~ween l~vO electrodes, while the burller ~ is arral)ged io nol)-ayllll)letFical In~a-lncl bel~vcell two eleelrodes.
As eoal, a powdered ~I)thracite coal ll~ving tlle rOllowill~ elemcl-t~ry analysis f tlle raw coal was ~lsed: .
. Carbol) C - 0.~3 ~ydrogen H = 0.034 Oxy~en O = 0.01~
Sltlphur S = 0.008 lo 0.01 Ni~rogen N = 0 015 Ash A = 0.093 Lower calorific Yal~le waS hu = 31,800 kJlkg = 8.83 I~Wh/kg ~Jpper caloriJ;c val~le was ho = 32,550 k~/kg = 9.04 kWh/k~, , ` Frol~ this tllere rcslllted a stoiclliolllelric oxy~cn re41drem~nt Or 0"~ = 1.73 m3 O~/k~ of f~lel and arlel- the stoichiolI~eîric con~b~slion witl~ O., .t fl~le ~,ilS composi~ion of ~CO~ = 79.62~o l~O = 19.43 %
. ~SOI =~ 0.:32 'Y"
~NI = 0.62%
~ 2 ~5 1 1 9 . 1'~ 6 -:, , :
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2 ~
' 9~ ~1/D2 12: 131 S 1 212 ~72 5-1~7 COHE~I i;oNT~
I he average charge ~eqllcnce was as toll()ws After a ~`irst cllarge of scrap of al)olli 76 lOnS h~(l been charged into the arc ~ rnace I in whicl) there was a melt resi~lue frolll the prece~lin~ batch the l)ulners 3 and 4 were then charged abo~l one n-inllte thereafter with tl~e ~ine-coal/oxygen mixture The i nilioll of the mixll)re upOI~ emer~el~ce from tl~e burner took placc in ~11 cases in~media~ely even Whell ll~e ~crap was slili col~l~ As a resull of ~he cons~rllcti()n of ~he burner a d~ yed n~ixillg ertec[ W`d`j ol~ained in rron~ of ils Inollth reslllting in a dift;~e ~/idely (~is~ersi~d flallle wl~ich effected excellenl ~ransll1issiol- of the heat of eoml)~lstion on~o ~e scr~p and tlle ~urface of ~l~e bn~ ]t ~vas noled tha~ after ~he jgnitk~n of tl~e flame a~ter the cl)arging of lhc scrap a large l-()llow space was meltéd wi~hi a short tin~e into ~he scrap wilhill wllich spac~ lhe namc developed in stal)le n~anner Coal charged dosa~ed from the r)ressure conveyors 5 with oxygen was fed via the conduits 8 to ~he burllers 3 and 4 wi~h sLIch a speed of conveyance th~t a spced ~f conveyallce of abou~ ~0 me~ers per secollt~ wa~ eslablishe~l ~vitl~in the nozzle Sincc this speed is elearly above the flame propagation sl)ced of Ib~)ut 35 n~/~econd backward burning was dependably avoided even in the cvent ur a mixillg Or coal an~l oxy~en wi~hill tlle burner as a res~llt of distllrb~n es Tlle speed of soulld i~ cstabli~;hed in tlle oxygcn fed via lhe eonduits 9 to the bllrners so thal upOIl emer~cnce irrom tlle c~rrespolldillg burner a prcssure of about I bar is presenl Atn~osplleri¢ I)ressllle prcvailed wilhin the .arc f~lrnace ~ The mass flow of ~he eoal varied l~etweell 2~ and 25 i;~/lllinll~e rOr each burner all(l was regl~la~ed .~
- in the ~ame way as ~he et)rlespondillg amollnl Or oxyg~n - in acc~)rdance wi~h lhc values le~ertnincd by ~he fllle-ga~ analysis Tlle an)ollllt o )` oxygel~ wa5 adjlls~ed "n the b~sis of ~toichiometric to slightly over stoichio)nelric combus~ion ~he powdered coal llad an averagc . .
.. . .. .
N~21SIIY.I`C'1' ~7~
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'~2 ~11/132 1~ !; 1 21~ ~72 ~i187 COHEII PCIIITRIII 13~ ~
~pecific gravlty of 1,400 k~/cubic melCr al~ n aver~e particlc si%e ~,r abnllt 40 ~n~ The qual~titative tlow of the nilrogen used as vehicl~ g as was ~(!jusled ~s low as possible, ob~ining a cl-arging coefficien~ ~u = M~ y of about 18 ~o 2() Tlle charge of scral~ was mclted do~YIl in about 15 ~ninlltes; ~he burl1ers were shu~ c t`t` an(~ charged wi~h air~ l`l)ereupoll a second charge of scrap ~Iso ot abo-l~ 7~ tons was t`ed to tlle are furnace, the strc~ .,r air was sl~ut off and tl~e burllers ignited agai~ or ~he nleltillg do~v~) of ~he second bd~Ch of scral), which was carricd out in the s~me n~ilnner, only abou~ 7 minlltes wcre requircd (l~ ) Tbe hurners werc tl~en removed from the furnace and the mclt was f~nislle~l by lneal~s Or electrode lleatin~ ~nd tapped off l`he ~apping telllper~lUre was oll tlle average aboll~ IS~U (: The ~apped \Yeigh~ w~s ai O~lt 140 lons and was distributed over two ladles rhe speeific use of cArboll wa~ abou~ 10 k~ of carboll per of 1i4uid steel, whic~l corresponds lo a sllpply of el)er~y of abou~ '~0 kWh/~on of s~eel and a ~legree of subslitution Or elcctri~ energy by coal of morc thall 70% 1`he average tlnalysis of ~ ferritic special-steel produced had the i`ollowillg values (in weight ,~ C c 008 ].~
Mn c 1.0 .
S ~ 0 03 Cr = 15 ~ ~ 17 5 Tlle lUbes of ~hc bllrl~er sll~ft 1~ wcre Ina~le of st~inless s~eel and, ~s a result of tlle diffetent condi~iolls of ~he local arran~elllen~, were o~ different len~h Tlle outside ;' ''.
N ~5119 PCr -8-~.
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' 9'~ 81/~!2 12: ~2 ;!; 1 212 972 5 1~7 COIIE~I PONT~NI l13 ' diameter ot tl-e sllafl ~vas abvul ~0 nll)l. I he weal on Ille mo~llh ot` the ~Jrners remained vithin lin~its, even afîe~ numero~ls cll~3r~es~ Both ferritic and aus~enitic stainless sleels ~vere melted. ~n the case of the melled austeniliC steels the .sl)ecit;c use of coal was nn the aYcrage set snlaller.
Thc method and the apl)aratlls of ~he i~lventi~n arc llo~ s~ al)le only for newly erecte~l plallts but, in par~icular, also for the re~rofitting o~ elc~llic arc ~>iants ~hich are lready ill opera~ion.
N ~ J~1 19.1'C'r ,,,, . :
,'' ', .. . ,. : . ,
9~ 57 ~ I ''I -' '~7~ 54~'7 COHEN P~IIITRIII ~2 METlIOD ANl~ Al'PAT~A'l US YOR HEATlNC A METALLuR('7lcAL FURNACE
Thc presen~ invenliol~ relates t~) a metl)od of hea~ g a tl~etallurgical furnace, in particular an electric arc furnace char~ed willl scrap or simila.r solid m~terials. Ivletllods of this type ale nIlmero~ls ~nd have been kno\vn for a long ~in~e and new olles are bcing cons~an~ly propose(i. Thus, for instance, in F`ederal Republic of C3ermany P~lellt 14 33 424 a melting fllrnace is described w hicll can be optionally healed witll burners and electro(les, oxy~en ;~n~ ow~k.r~.fl fll(~.lc ~ in(rl~ ,c~l vi,~ Ihe l~ .rs. I-iow~vel. Iultllel details concerllill~ Ille l~urner he~ling are not given in ~llc patcll~. Frcqllcnlly, exclusively ~as or oil :: burllers arc clllployed in S~lCtl methods, as for installce in ~hc mctllod in accordance with l~e~Jeral Republic of Gcrlnany 25 41 0P~6.
.~~P-A-O 200 ~0~ ~Ic~-:rlt~s ~ UU ur ~ ur~ rurn~ tn which ~owdered coal of a particlc sizc Or 4.S ~m and an approxima~ely .stoicl-iollletl-ic 4uanllty of oxy~,en is fe~l tllro~lgll a burner. ln this case, the fuel, th.lt is the coal, is fed by a .5~ream of vehicle ~as whicll sLIrlollllds tlle inller oxygell cha-lllel allnlllarly. Finally, such a me~ho~l is i~lso knowll from EP^i~ 4 ~78, carbon of a ~i7.e less thal- 10 /ln- being fed by mc~lls of an inerl slream of vehicle gas.
The objecl of the preseni in\~entioll is to iml.lroYc thc prior art by a ncw metllod so that thc heating and melling c~all be carrie~l Oul reliably all(l ecollolllically an~l to ill(licate ~n apparalus wl~ic~l is l~r~icularly sui~ble rOr IhiS p~lrpoSe. ]`or thiS purpose 4 to 15 I>f po~ ert ll coal of a particle sizc of ~ ''00 ~m per lon of 1i4uid melal produced is red in an inerl to sli~htly reducillg Yclliclc gas witll a veloci~y Or al leasl 4~5 m/second at lea.s~
124~119.1~C'I' .
~ ' . '. :,~ -. : :, :
.- - ` , ~: ~ ` . : : ' - 2~37l1 ' 9 2 ~ 5 7 ;!: 1 2 1 2 9 7 2 5 ~ ~: 7 I, o H E l l P :: I I T ~ 3 d~uing the melting down nf the c~argc and is burned witl~ form~liol) of a ~liffuse ~lame"
stoichiomelrically lo s]ightly al)ove stoichiomelrically l~y oxy en lo~r~ing from Ihc burl)er a~
the spe~d ~f su~lnd and a pre.jsur~ Or a~ si nne ~ar.
With this new loethod all types of steel ~nd ferro-alloys lS we]l as s~lit~ble noll-ferroos melals can be treat~d. An increase in output of abo~lt ]0"~o as wcll as a redllclion in the fecd of electric ener~y by abollt 5~ KWh/t can be oblailled alleady wilh av~rage amollnt.j of chargc.
Advanla~eolls en)bodil~ s Or ~lle invel)tion arc indicated in Ihc other Inetl-odclairns. lt has sllrl~risin~ly been fo~ d th~t as comparcd wi~h the preViO~ls~y known methods of operalit)ll considerable improve1ncllts in tl~e resull of the operatioll can ~e ob~ained by the use of the methnd nf thc present invenliOIl~ In this conn~clioll the paramelers of tllc method were prefer~bly so selected th~t ~I)e pressure of ~he emergillg oxygen is al leas~ 0. ~ bar above ;: ~he intcrllal pressllre prevailillg withill ~he rurnacc that tl-~ p~)~vdered coal is fed in amoullts of S to 10 I;g/t of liquid mct~l produ~ed ~h.l Il~e velocity of Ihe vehic]e gas is at ~e;~sl ~0 ~ ~ -M/second and that the pressure in tl~e oxygen line (pre-pressure) is adj~lste-l to 12 In 16 bar ~-and pr~fera~)ly 13 to 15 bar. l~he fucl ~Ised is preferal)]y a po~v~ler~l co~l con~ail~ 8 ~o l 5 % vo]~lile colnpollents ~:
If it is intell(led l~l add the SCl;1p b.llch-~Yise fnr insl~nCe in c~lstomary Inanller in the char~in~ c lge it is advant~olls ln s~art the introd~clioll of coill and oxygen wi~hin lwo minlltes after thè charging. This inlr( d~lction is ~.dv~n~ageously conlinued for a pèriod of 9 ~o 17 minutes d~lrin~ a batcb se4ucncc.
.Y:3~J51~9,1~`'1' -2-`':
~ -- . - , :,. . .
;, - ' '-, ............ , -' '- " '"' ~ . , . ~ ~
. . .
2~371 ~
~g2 01/~2 11:58 ;!; 1 212 972 54~7 ~IHEN P~)llTfllll 04 '. ' .
Particularly favor~hle resl~lts ca~ e obtain~d if the raLio of the mass flow of coal to ~hal Or vehicle gas is 10 to 2t) l)pon the chargis~ of the furn lce witll scrap or the like l~y means for inst~llcc of a charging cage, thc l~llrners are preferably ren~o~ed fron~ thc f~rnace, When introduced l~ll nol in th~ir operatin~ phase or phases lhe burners are chalged with a .~icavengin~ ~as preferably air al le~st in the fuel cl~anlle~ orcler lO ~eep lhe channels open 1 h~ qualltity fed amoun~ in this conncction preferah]y IO 170 to 200 lin~'/hr dependin~ on tllc sizc of lhe ~urner.
A j ~pp~ratus for the carrying out ~)f the ~netl~od tl~ere is yrovid~d a bllrner which has a shaf~ formed of ~wo concentlic l~ll)CS, lhe annular ch~nllel thereof discl~arging into a widened annlllar spaCe of ~ distribl~tor holes arranged annularly an~l cohxidlly to the shaft debourhing into thc annular sp~ce frolll the opposi~e side Ihe l`ee~ side ~ait5 holes ~eing connccted n~ their feed side to a fuel con~ an(J hy ~n oxygen feed line conlleclcd lo Ihe oxy~en channel formed by Ihe hlller luhe of ~he sllafl Advanl~geollS developmenl~ of Ihe new burller arc se~ for~h in tl~e 7~lt~ched apparal~ls clail~
rhe method of the invenlion and the app~ratl,s for the calrying out of Ihe lhod will be explained in fllrlher delail with reference to the drawillgs eacl~ of which shows onc elnhodin~ent of the metllod and lhe as~par~lus ln lhe dr.lwing:
I`ig I is ~ diagral7~ of a plan f~)r lhe fee~ing of n~terial to all arc furllace.
Fi~ 2 is a diagrammatic hori~ontal sèc~ion tllrougll the arc f~rnace of l~ig. 1.
Fi~ ~ is an Ou~pllt cllrve of a bllrner.
., .
; -3-2~7 l~
..-.,, 02 1 I: 5g ~ 1 2 1 2 972 54~7 CrJHEII P01ITRNI ~5 '.
~ig. 4 shows the main piece of a burner half in outer view and half in klngitudinal sectic~n.
~s shown in the diagr~m of l ig 1, in Ihc case of an ele~tric arc furnace I
having three e]ectr/)dcs ~ lwo burllers are inlroduc~ rou~h tl~e walel-cooled ~urnacc wall c~n ~hc si~e al)o\e the melt Eacll of ~ wo ~)urners ~ and 4 has a pressule conveyor 5 each provided with a weighing device ass~)ciated wiih it ~he pressurc conYeyors ~ bcing ~upylie~l fron~ a stora~e bin 6 with powdered coal which i~ possibly c~assified in an interposed screenin~ d~vice 7 The coal withdrawn Irol~ tlle press~lre conv~yors 5 i5 ïed lo Ihc burners 3 and 4 via cunduits 8 wilh nitr(lgell flol-- ia sn~lrce of ni~ro~cn nol showll The fe~din~ of oxyg~n to lhe bl~rner~ 3 and 4 is effecled Vi;1 ~wo conduils g. rlle furnace ] is furtllermore provided with A known device 10 for determinillg the cxllalJs~-~As analysis whicll is used to regulate the mass flows fe~ lo the burners wilh dlle consideralioll als~- of tl)e efficiency, reterred to dirfcrellt typeS and Cl)lllpO!;itiOlls of coal The amoull~ of tlue gas is in lhis conncctio1l nlcasllred by the knowll He-tracer mctho(l usill~ d ~ilreaI11 of helium wl-ich is introduced illtO the furndce.
Fig. 4 shows the constrl~cli- n of ~he burners: Adjoining a shAt`t l~l which consists of lwo concentric tutles l l ~nd 12 and can be displa(:ed lo~ udillally into the furll~ce, ~here is the ~lclual parl of the burncr a ~listribu~or 14 formed of scveral parts of rotational sylnmetry Thc annular Cll~nlle] 1S de~cloped betweell tl~e two ~u~es 1l al-d l2 debouches in~o a widen~d annular space 16 of lhc di~lribulor 14. J rom the opposile side namely tlle feed sid~ f~c~llg aw~y from ~hc anl1ular cl~anncl l.~, six ho]es 17 whicll are arranged annlllarly an(l coaxial lo the shaft 13 ~lèhollch into ~he anlllllar space 16"he holes N~ Sl I 9.1~ 4-,; .
.. ' -' - ~' ' ,' : ,' .
: ,- , - .. , - : ~ . .
2~63711 ' ~2 e~ 2 1 1: 5'3 7 1 2 1 2 972 5487 COHE~I PONTf:llJ I ~G
bcill~ conl)ected on the feed si(ie lo a cylindrical collection space l8 A fllel conduit 8 for lhe feeding of the coal is flange(l onto ~he cnd ~ f ~l~e collcction s~ace i ~ coaxial lo tl-e di~triblltor 14 ~he condl)it 9 for the fe~rling of oxy&en is c~nnected (o ~ll anlllllar collection space 19 which sullounds a po~-sl~aped sLlpport melllber 20 witl-in which the holcs 17 are arrall~ed Tlle collection space 19 is connecte~l via six radial c)l~nnels I ex(ending in ~ach case be~ween the holes 17 to the o ~y~en ~llallnel 22 tormed l~y tlle inner l~be 12 -, Tllc ann~llar space 16 is forl~cd by ~ in~,erlioll of a snit~hly sllaped inseltion member 2~ in s~lch ~l mallller Ihal ~he gr~test part of i~s inller wall wi~lens to\~/ards ~he holes - ]7 so that the Idr~,cst diam~ter of thc inner wall agrees Willl tlle ~mallest diameter, nalllely ~he corc diarnelcr, of the circle or holes 17 ~n lhc oppusite side, the ann~llar space l ~
rorn~s an end surface 24 All parts of the ~listribu~or 14 are pllshe~J one on Ihe other and fastened to each other by flange collllectiol~s so Ihat simple assemhljllg and taking aparl of lhe bllrner is possib~e rhe deve~opmen~ of tl~e (li~lrib~ltor 14 in accordance witll the invenlion fur~hermore results in ~he a~lvant~ge Or only sli~llt weilr of tlle parts condllclil-g the po~dere~l coal ~elween the colleclion space 18 all~ lhe fuel condllit 8, a b~ffle plate 27 - havin~ ~hrce openill~,s 28 is provided as ~low distriblltol, it retardill~ ~he str~ Or vellicle ~as laden ~vith coal dust and dividing it into lllree individnal streams The ol~enil)gs 28 are ; ~ so arranged Ihdl cacll Or lhe three indiVid~lal streallls is ~listribll~ecl over ~,vo of Ihc six holes 17, in which it is f~rlhcr decelcrate~l Acceleration lakes pl~ce again only al the transition into the annl~lar ch,tnnel IS By lhis conslruc~ of tlle nozzle, ~llc wear of the distributor 14 by abrasion is still fllrther reduced Nl~lJ~llV,I'I.`'I' 5 .
2~71~
' g2 13 1 ~12 1 2: 0~1 2; 1 2 1 2 ~2 5~ 7 COHEiJ ~nNTn\~ 7 '. .
ILl~usTRA~lyE EJ~ oOlMEl~T
I`he method of the invenîioll was ~l~ed on a 140-t~UHP electric arc fl~rnace, ~he ~rrallg~ment shown in Fig, I being llsed. Tl~e ~wo t)urllt~rs ~ ~nd 4 wcre jo ~rr~ hal the one burncr 3 ex~ lc~ acl(cct thr~ ugl~ tho 51n6 dool r)S, int~ )r fl)rl~c~ 1 alld the other t urner 4 was inserted ~hro~gh lhe fllrnace wall 90G away rrol~ )c burncr ~ lhrollglI a sui~able opening, as cal~ be noted from I~i~,. 2. 1~ c~n r~lrll~ermore bt! noted froll- Fig. 2 lhat - ~
tl)~ burner 4 is directed in the so-calied "cold s~ot" rcgiol~ 26 be~ween l~vO electrodes, while the burller ~ is arral)ged io nol)-ayllll)letFical In~a-lncl bel~vcell two eleelrodes.
As eoal, a powdered ~I)thracite coal ll~ving tlle rOllowill~ elemcl-t~ry analysis f tlle raw coal was ~lsed: .
. Carbol) C - 0.~3 ~ydrogen H = 0.034 Oxy~en O = 0.01~
Sltlphur S = 0.008 lo 0.01 Ni~rogen N = 0 015 Ash A = 0.093 Lower calorific Yal~le waS hu = 31,800 kJlkg = 8.83 I~Wh/kg ~Jpper caloriJ;c val~le was ho = 32,550 k~/kg = 9.04 kWh/k~, , ` Frol~ this tllere rcslllted a stoiclliolllelric oxy~cn re41drem~nt Or 0"~ = 1.73 m3 O~/k~ of f~lel and arlel- the stoichiolI~eîric con~b~slion witl~ O., .t fl~le ~,ilS composi~ion of ~CO~ = 79.62~o l~O = 19.43 %
. ~SOI =~ 0.:32 'Y"
~NI = 0.62%
~ 2 ~5 1 1 9 . 1'~ 6 -:, , :
~ _ ... .. . .. .. .. . _ _ . . .
2 ~
' 9~ ~1/D2 12: 131 S 1 212 ~72 5-1~7 COHE~I i;oNT~
I he average charge ~eqllcnce was as toll()ws After a ~`irst cllarge of scrap of al)olli 76 lOnS h~(l been charged into the arc ~ rnace I in whicl) there was a melt resi~lue frolll the prece~lin~ batch the l)ulners 3 and 4 were then charged abo~l one n-inllte thereafter with tl~e ~ine-coal/oxygen mixture The i nilioll of the mixll)re upOI~ emer~el~ce from tl~e burner took placc in ~11 cases in~media~ely even Whell ll~e ~crap was slili col~l~ As a resull of ~he cons~rllcti()n of ~he burner a d~ yed n~ixillg ertec[ W`d`j ol~ained in rron~ of ils Inollth reslllting in a dift;~e ~/idely (~is~ersi~d flallle wl~ich effected excellenl ~ransll1issiol- of the heat of eoml)~lstion on~o ~e scr~p and tlle ~urface of ~l~e bn~ ]t ~vas noled tha~ after ~he jgnitk~n of tl~e flame a~ter the cl)arging of lhc scrap a large l-()llow space was meltéd wi~hi a short tin~e into ~he scrap wilhill wllich spac~ lhe namc developed in stal)le n~anner Coal charged dosa~ed from the r)ressure conveyors 5 with oxygen was fed via the conduits 8 to ~he burllers 3 and 4 wi~h sLIch a speed of conveyance th~t a spced ~f conveyallce of abou~ ~0 me~ers per secollt~ wa~ eslablishe~l ~vitl~in the nozzle Sincc this speed is elearly above the flame propagation sl)ced of Ib~)ut 35 n~/~econd backward burning was dependably avoided even in the cvent ur a mixillg Or coal an~l oxy~en wi~hill tlle burner as a res~llt of distllrb~n es Tlle speed of soulld i~ cstabli~;hed in tlle oxygcn fed via lhe eonduits 9 to the bllrners so thal upOIl emer~cnce irrom tlle c~rrespolldillg burner a prcssure of about I bar is presenl Atn~osplleri¢ I)ressllle prcvailed wilhin the .arc f~lrnace ~ The mass flow of ~he eoal varied l~etweell 2~ and 25 i;~/lllinll~e rOr each burner all(l was regl~la~ed .~
- in the ~ame way as ~he et)rlespondillg amollnl Or oxyg~n - in acc~)rdance wi~h lhc values le~ertnincd by ~he fllle-ga~ analysis Tlle an)ollllt o )` oxygel~ wa5 adjlls~ed "n the b~sis of ~toichiometric to slightly over stoichio)nelric combus~ion ~he powdered coal llad an averagc . .
.. . .. .
N~21SIIY.I`C'1' ~7~
:
'~:
~3~i~
'~2 ~11/132 1~ !; 1 21~ ~72 ~i187 COHEII PCIIITRIII 13~ ~
~pecific gravlty of 1,400 k~/cubic melCr al~ n aver~e particlc si%e ~,r abnllt 40 ~n~ The qual~titative tlow of the nilrogen used as vehicl~ g as was ~(!jusled ~s low as possible, ob~ining a cl-arging coefficien~ ~u = M~ y of about 18 ~o 2() Tlle charge of scral~ was mclted do~YIl in about 15 ~ninlltes; ~he burl1ers were shu~ c t`t` an(~ charged wi~h air~ l`l)ereupoll a second charge of scrap ~Iso ot abo-l~ 7~ tons was t`ed to tlle are furnace, the strc~ .,r air was sl~ut off and tl~e burllers ignited agai~ or ~he nleltillg do~v~) of ~he second bd~Ch of scral), which was carricd out in the s~me n~ilnner, only abou~ 7 minlltes wcre requircd (l~ ) Tbe hurners werc tl~en removed from the furnace and the mclt was f~nislle~l by lneal~s Or electrode lleatin~ ~nd tapped off l`he ~apping telllper~lUre was oll tlle average aboll~ IS~U (: The ~apped \Yeigh~ w~s ai O~lt 140 lons and was distributed over two ladles rhe speeific use of cArboll wa~ abou~ 10 k~ of carboll per of 1i4uid steel, whic~l corresponds lo a sllpply of el)er~y of abou~ '~0 kWh/~on of s~eel and a ~legree of subslitution Or elcctri~ energy by coal of morc thall 70% 1`he average tlnalysis of ~ ferritic special-steel produced had the i`ollowillg values (in weight ,~ C c 008 ].~
Mn c 1.0 .
S ~ 0 03 Cr = 15 ~ ~ 17 5 Tlle lUbes of ~hc bllrl~er sll~ft 1~ wcre Ina~le of st~inless s~eel and, ~s a result of tlle diffetent condi~iolls of ~he local arran~elllen~, were o~ different len~h Tlle outside ;' ''.
N ~5119 PCr -8-~.
'~
- : .. . : . ~. . .. . ..
: - , ~ . " :' 2 Q ~
' 9'~ 81/~!2 12: ~2 ;!; 1 212 972 5 1~7 COIIE~I PONT~NI l13 ' diameter ot tl-e sllafl ~vas abvul ~0 nll)l. I he weal on Ille mo~llh ot` the ~Jrners remained vithin lin~its, even afîe~ numero~ls cll~3r~es~ Both ferritic and aus~enitic stainless sleels ~vere melted. ~n the case of the melled austeniliC steels the .sl)ecit;c use of coal was nn the aYcrage set snlaller.
Thc method and the apl)aratlls of ~he i~lventi~n arc llo~ s~ al)le only for newly erecte~l plallts but, in par~icular, also for the re~rofitting o~ elc~llic arc ~>iants ~hich are lready ill opera~ion.
N ~ J~1 19.1'C'r ,,,, . :
,'' ', .. . ,. : . ,
Claims (21)
1. A method of heating a metallurgical furnace, in particular an electric are furnace charged with scrap or similar solid charge materials, in which oxygen and fuel are introduced through the wall of the furnace through at least one burner above the melt, the fuel being fed by a stream of vehicle gas which annularly surrounds the inner oxygen channel, in which connection as fuel, 4 to 15 kg of powdered coal of a particle size of less than 200 µm per kg of liquid metal produced is fed in an inert slightly reducing vehicle gas at a speed of at least 45 m/second, at least during the melting down of the batch, and burned, stoichiometrically to slightly over stoichiometrically, by the oxygen emerging with approximately the speed of sound and a pressure of at least about 1 bar from the burner with the formation of a diffuse flame.
2. A method according to claim 1, characterized by the fact that the pressure of the emerging oxygen is at least 0.1 bar above the internal pressure prevailing in the furnace.
3. A method according to claim 1 or 2, characterized by the fact that powdered coal is fed in amounts of 5 to 10 kg/ton of liquid metal produced.
4. A method according to claim 1, 2 or 3, characterized by the fact that the speed of the vehicle gas is at least 50 meters/second.
5. A method according to any of the preceding claims, characterized by the fact that the pressure in the oxygen feed line (pre-pressure) is set to 12 to 16 bar and preferably 13 to 15 bar.
6. A method according to any of the preceding claims, characterized by the fact that a powdered coal containing 8 to 15% volatile components is used.
7. A method according to any of the preceding claims in which scrap or the like is added batchwise, characterized by the fact that the introduction of coal and oxygen is started within two minutes after the charging of the scrap.
8. A method according to any of the preceding claims, characterized by the fact that the introduction of coal and oxygen is effected over a period of time of 9 to 17 minutes during a charge sequence or after each batchwise addition of scrap.
9. A method according to any of the preceding claims, characterized by the fact that the ratio of the mass flow of the coal to that of the vehicle gas is 10 to 20.
10. A method according to any of the preceding claims, characterized by the fact that the burner or at least part of the burners are removed from the furnace at least during the charging.
11. A method according to any of the preceding claims, characterized by the fact that the burner or burners, in introduced condition is or are charged, outside the operating phase or phases, with a scavenging gas at least in the fuel channel.
12. A method according to any of the preceding claims, characterized by the fact that as scavenging gas air is fed in an amount of 170 to 200Nm3/hr.
13. A method according to any of the preceding claims for the heating of an electric are furnace, characterized by the fact that at least one burner is associated with each inter-electrode space (cold spot region).
14. An apparatus for carrying out the method according to any of the preceding claims, having a burner with a shaft (13) which is formed of two concentric tubes (11, 12) and the annular channel (15) of which debouches into a widened annular space (16) of a distributor (14), holes (17) which are arranged annularly and coaxially to the shaft debouching into the annular space (16) from the opposite side, the feed side, and being connected at their feed side to a fuel conduit (8), and having an oxygen feed line (9) connected with the oxygen channel (22) formed by the inner tube (12) of the shaft.
15. A burner according to claim 14, characterized by the fact that a flow divider arranged in the fuel conduit (8), preferably a baffle plate (27) provided with openings, is arranged in front of the holes (17).
16. A burner according to claim 14 or 15, characterized by the fact that the inside diameter of the annular space (16) agrees, at least in the region thereof adjoining the shaft (13), with the inside diameter of the annular channel (15).
17. A burner according to claim 16, characterized by the fact that the inner wall of the annular space widens outward towards the holes (17), preferably up to the core diameter of the circle of holes (17).
18. A burner according to any of claims 14 to 17, characterized by the fact that the annular space (16) in the region of the mouth of the shaft (13) forms an end surface (24).
19. A burner according to any of claims 14 to 18, characterized by the fact that the oxygen feed conduit (9) debouches into an annular collecting space (19) which surrounds the holes (17) and connected via radial channels (21) with the oxygen channel (22).
20. A burner according to claim 19, characterized by the fact that the radial channels (21) extend between the holes (17).
21. A burner according to any of claims 14 to 20, characterized by the fact the the holes (17) are arranged in a pot shaped support body (20) developed as a body of revolution which is connected to the adjacent part or parts by being coaxially pushed onto one another.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3921807.4-24 | 1989-07-03 | ||
| DE3921807A DE3921807A1 (en) | 1989-07-03 | 1989-07-03 | METHOD AND DEVICE FOR HEATING A METALURGIC OVEN |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2063711A1 true CA2063711A1 (en) | 1991-01-04 |
Family
ID=6384181
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2063711 Abandoned CA2063711A1 (en) | 1989-07-03 | 1990-06-25 | Method and apparatus for heating a metallurgical furnace |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0480944A1 (en) |
| JP (1) | JPH05500847A (en) |
| BR (1) | BR9007498A (en) |
| CA (1) | CA2063711A1 (en) |
| DE (1) | DE3921807A1 (en) |
| ES (1) | ES2023064A6 (en) |
| WO (1) | WO1991000366A1 (en) |
| ZA (1) | ZA905023B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4434369C2 (en) * | 1994-09-15 | 1997-08-07 | Mannesmann Ag | Method and device for the metallurgical treatment of iron |
| AT402963B (en) * | 1995-09-07 | 1997-10-27 | Voest Alpine Ind Anlagen | METHOD FOR BURNING FUEL |
| EP0787966A1 (en) * | 1996-02-09 | 1997-08-06 | Linde Aktiengesellschaft | Process for melting and holding at temperature of metals |
| RU2219247C2 (en) | 1998-08-28 | 2003-12-20 | Фоест-Альпине Индустрианлагенбау ГмбХ | Method and multifunctional lance for production of melted metal (options) |
Family Cites Families (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1433424B2 (en) * | 1962-11-29 | 1971-01-28 | Fried Krupp GmbH, 4300 Essen | Multi-furnace melting plant, especially for steel production from scrap and coal |
| GB1099959A (en) * | 1965-10-28 | 1968-01-17 | Janos Miklos Beer | Improvements in or relating to burners for pulverised coal or like solid fuel or for liquid or gaseous fuel |
| DD107526A1 (en) * | 1973-05-09 | 1974-08-05 | ||
| DE2541086A1 (en) * | 1975-09-15 | 1977-03-17 | Toshin Steel Co | Steel mfr. starting from cold scrap - in arc-furnace fitted with burners for oil, air, and high-velocity oxygen |
| JPS5687617A (en) * | 1979-12-19 | 1981-07-16 | Daido Steel Co Ltd | Steel making method using arc furnace |
| DE3367117D1 (en) * | 1982-09-02 | 1986-11-27 | Shell Int Research | Burner for the partial combustion of finely divided solid fuel |
| FR2535018B1 (en) * | 1982-10-22 | 1987-04-24 | Air Liquide | PULVERIZED COAL BURNER |
| EP0164878B1 (en) * | 1984-05-11 | 1991-01-23 | JAMES HOWDEN & COMPANY LIMITED | Method of operating metallurgical furnace |
| GB8509629D0 (en) * | 1985-04-15 | 1985-05-22 | British Steel Corp | Melting ferrous solids |
| GB8516143D0 (en) * | 1985-06-26 | 1985-07-31 | British Steel Corp | Melting of metals |
| DE3542829A1 (en) * | 1985-12-04 | 1987-06-11 | Kloeckner Cra Tech | Process and nozzle for producing steel from solid raw materials |
| DE3629055A1 (en) * | 1986-08-27 | 1988-03-03 | Kloeckner Cra Tech | METHOD FOR INCREASING ENERGY IN ELECTRIC ARC FURNACES |
| FR2634787B1 (en) * | 1988-08-01 | 1991-11-29 | Siderurgie Fse Inst Rech | PROCESS FOR OBTAINING A FOAMING SLAG IN AN ELECTRIC STEEL FURNACE |
-
1989
- 1989-07-03 DE DE3921807A patent/DE3921807A1/en not_active Withdrawn
-
1990
- 1990-06-25 JP JP2509028A patent/JPH05500847A/en active Pending
- 1990-06-25 BR BR909007498A patent/BR9007498A/en not_active Application Discontinuation
- 1990-06-25 WO PCT/DE1990/000487 patent/WO1991000366A1/en not_active Application Discontinuation
- 1990-06-25 CA CA 2063711 patent/CA2063711A1/en not_active Abandoned
- 1990-06-25 EP EP90909333A patent/EP0480944A1/en not_active Withdrawn
- 1990-06-27 ZA ZA905023A patent/ZA905023B/en unknown
- 1990-07-02 ES ES9001817A patent/ES2023064A6/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| ES2023064A6 (en) | 1991-12-16 |
| BR9007498A (en) | 1992-05-19 |
| EP0480944A1 (en) | 1992-04-22 |
| JPH05500847A (en) | 1993-02-18 |
| DE3921807A1 (en) | 1991-01-10 |
| WO1991000366A1 (en) | 1991-01-10 |
| ZA905023B (en) | 1991-04-24 |
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