future-oriented oxygen steel production · content 23future-oriented oxygen steel production...
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FUTURE-ORIENTEDOXYGEN STEEL PRODUCTION FUTURE-ORIENTEDOXYGEN STEEL PRODUCTION
STEELMAKING
SteelmakingSMS DEMAG
2
SMS Demag, a synonym for leadingknow-how and long-term solutions forthe entire process chain of metallurgicaltechnology and steel production.
Planning, project engineering, design anddelivery, as well as operator training andthe supply of metallurgical know-how foran optimised sequence of production inintegrated steel mills, characterise thewide range of equipment and servicesoffered by SMS Demag.
The constant further development of all steelmaking modules and processsteps forms the basis for optimised steelmill design concepts for the enhance-ment of investment profitability.
Extensive relations with reputed steelmill users worldwide and with nationaland international research institutionscontribute considerably to the successfulaccomplishment of this aim.
Engineers with ample experience in allpertinent disciplines and utilising themost advanced data-processing tech-niques are constantly engaged in trans-lating the process parameters into opti-mum module and component designs.
Steel refining in a converter is an im-portant link in the chain of interrelatedproduction steps in the manufacturingand further processing of steel.
The advent of the oxygen blowing prac-tice in the fifties marked a giant stepahead and a new epoch in steelmaking.The basic practice was the blowing ofpure oxygen on top of the metal bath in the converter vessel. The resultingquick conversion of material and energywere the basis for success.
The 30-t vessels of the mid-fifties quicklybecame production units capable of hold-ing up to 400 t of melt weight and yield-ing 600–650 tonnes per hour.
Optimisation, further development, andinnovations led to increased productionand tangibly contributed to qualityimprovements and the cost effectivemanufacture of high-quality products.
FUTURE-ORIENTEDOXYGEN STEEL PRODUCTION FUTURE-ORIENTEDOXYGEN STEEL PRODUCTION
CONTENT
2 3 Future-orientedoxygen steel production
4 9 Converters
10 11 Change vessel converters
12 13 Blowing lances
14 15 Slag splashing and bottomstirring
16 17 Sublances
18 19 Waste gas analysisSonicmeter
20 23 AutomationSlag retaining devices
24 25 Relining equipment
26 27 Dust collection, gas cleaningand gas recovery
28 29 Erection and commissioning
30 31 SMS Demag converter equipment
3
SteelmakingSMS DEMAG
4
CONVERTERSCONVERTERS
For the production of quality steels, theLD converter with its oxygen top blowinglance and vessel bottom tuyeres for inertgas stirring has found general accep-tance.
Special steels are chiefly made in MRP(Metal Refining Process) or AOD (ArgonOxygen Decarburisation) converters inconjunction with electric arc furnaces andvacuum degassing facilities.
Depending on the blowing method,whether LD, AOD or MRP (with or with-out top blowing lance), the shapes of theconverter vessels are more or less slen-der or big-bellied, with symmetrical ornon-symmetrical vessel top cones orwith integral or replaceable bottoms.
Special attention is paid in the designingof a converter to the service life of theconverter vessel and of the trunnion ring.The material of which a converter vesselis made is subject to extreme thermalstressing during the steelmaking process.The temperatures in the vessel wallsattain about 420 °C and in the trunnionrings about 210 °C. This implies loadvalues not far below the yield strength of the materials.
Thomas Converter 1879
– Short bottom life– Small heat size– High N-content in steel– Slopping– Pollution– Low scrap consumption
LD converter 1948
– High productivity– Low N-content– Low pollution– Slopping– Remote from
steel/slag equilibrium
QBM/Q-BOP 1968
– Low productivity– Low N, P, S, C, O– Low (FeO) in slag– No slopping– Low pollution– Low scrap rate
AOD 1969
– Low gas con – Low sulphur– Better yield
Heat size [t] Height [mm]
Volume [m3] Diameter [mm]
9810
8570
7862
6050
300
220
140
50
268 117 50 1785 2470 3320
31752930200068181
68006815
8720375
11080
200 88 2263
Developments in respect of convertervessels and blowing processes.
LD converter volumes.
5
Comb-blowing 1977
– Bottom and top-blowing with O2
– Lime injection– Post-combustion– Higher scrap rate
KMS converter 1978
– Bottom and top-blowing with O2
– Coal injection and/orscrap preheating
– Lime injection– Post-combustion– Very high scrap rates– Large amount of
valuable offgas
LD-CB 1981
– Increased yield– Savings in ferro-alloy
and fluxes– Reduction of
inclusions
MTBI (MWH) 1981
– Higher yield– No slopping– Additive savings
MRP 1983
– High mixing energy– Low carbon content– Low gas content– Very low sulphur– Fewer inclusions
tent
Heat size [t] Height [mm]
Volume [m3] Diameter [mm]
74306620
57505548
4090
3766
3080
62.5
75105
5035
15
8
5
29.7 17.4 4.3 1960 2760 4200 55005000276019602.26.848
Heat size [t] Height [mm]
Volume [m3] Diameter [mm]8
6345
4300
4570
3890
3630
80
15
20
10
7
10 2220152511453.836
13601225
3.62
MRP converter volumes. AOD converter volumes.
SteelmakingSMS DEMAG
6
CONVERTERSCONVERTERS
SMS Demag now uses a highly tempera-ture-resistant, fine-grained structuralsteel specially developed by a reputedGerman steelmaker.
This new grade offers a higher yieldstrength than, for instance, German steelgrades 13 CrMo 4–5 or 10 CrMo 9–10 or American steels ASTM A387, grade12 and grade 22, and thereby significantlyimproves the service life of the convertervessels and the trunnion rings.
The yield strengths of the new material,as well as the chemical analysis andmechanical properties, are comparedwith the conventional steels in the dia-grams/tables.
Vessel
420 °C790 °F
310 °C590 °F
380 °C720 °F
150 °C300 °F
Trunnionring
180 °C360 °F
210 °C410 °F
125 °C240 °F
180 °C360 °F
C Si MN P S Cr Ni Mo V
(%) (%) (%) (%) (%) (%) (%) (%) (%)
0.17 0.25 0.92 0.19 0.003 0.70 1.90 0.52 0.093
CHEMICAL COMPOSITION
750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
0.2%
yiel
d po
int
in N
/mm
0 50 100 150 200 250 300 350 400 450 500 550 600 650 700
XABO 690Actual value
XABO 690Minimum value
P356NH
13CrMo4–5
10CrMo9–10
16Mo3
P275NH
Temperature in °C
Minimum yield strength of heat-resisting steel depending on temperature
Temperatures in the vesselwall and the trunnion ring.
Yield strengths.
7
0.2% yield strength Tensile Elonga- Impact strength tion energy
in N/mm2 in N/mm2 in % in J
Rt 400 °C 500 °C 550 °C 600 °C Rt Rt –20 °C
724 588 532 483 302 803 19.8 151
MECHANICAL PROPERTIES
Charging of a converter vessel.
SteelmakingSMS DEMAG
8
CONVERTERSCONVERTERS
Other noteworthy features of the SMS Demag converter system are thereplaceable bottom, the cooling of thevessel top cone, and the specially devel-oped drive, which allows 100% torqueequalisation among the drive trains and freedom from backlash in the gearflanks when the converter is in its work-ing position.
Another important criterion for trouble-free operation is the method of vesselsuspension in the converter trunnionring.
Two fixing systems have proved theirworth in the course of many years here:
The lamella packs for stationaryconverters.The tensioning elements for change-vessel converters.
The essential feature of the fixing sys-tems is the fact that the vessels are ableto expand to the greatest possible extentwithout any hindrance.
These designs locate and center the ves-sels troublefree in every tilting positionand without any backlash in the trunnionring, thereby ensuring a uniform loadingof the latter.
Converter drive. MRP converter.
Lamella packs.
Vessel tendons.
9
Suspension for stationary converters.
LD converter. AOD converter.
Suspension for change-vessel converters.
SteelmakingSMS DEMAG
10
CHANGE-VESSELCONVERTERSCHANGE-VESSELCONVERTERS
The change-vessel converter design represents an alternative to equipping a meltshop with several permanently installed converters, each with all of thenecessary ancillaries for a steelmakingstation, such as bins, fume exhaust sys-tem, lance equipment, ladle and slagtransfer cars, etc.
The advantage of the change-vessel typeis that it is possible to lift the vessel outof the trunnion ring when the refractorybrickwork is eroded and replace it byanother vessel newly lined in an off-con-verter rebricking area. Vessel changingtimes range between two and 16 hours
(approx. six hours on average). Vesselchanging is carried out when the convert-er is down for scheduled maintenanceanyway. Accordingly, the annual capacityof the change-vessel converter is equalto a conventional one-two operation.
The investment costs for the additionalequipment necessary for the change-vessel type, such as vessel changing car,wrecking and rebricking stand as well aswaiting stand for the newly lined vessels,are relatively low compared with thecosts of an additional, fully equipped con-verter operating station.
Change-vessel converter facility at HKM.
Change-vessel converter facility at HKM.
11
Illustration of a change-vessel facility.
SteelmakingSMS DEMAG
12
BLOWING LANCESBLOWING LANCES
Oxygen blowing lances decisively in-fluence the process of decarburisation.
The blowing lances are exposed toextreme stresses in the reaction space.Steel and slag skulling on the lances is frequent. The oxygen exits from thelance tip nozzles at high velocities, whichis conducive to rapid wear and negativelyinfluences the shape of the oxygen jet.
One consequence is that lance changingis a necessity.
In conventional lance systems, the mediaconnection pipes are generally an integralpart of the lance. Thus, lance changingmeans the unbolting of numerous flangesand the separate disconnection of themedia supply and return hoses.
Lance changing often takes up to sixhours as safety regulations prescribe thatwork in the area above the converter ispermitted only during blowing breaks.
SMS Demag, in close cooperation withThyssen Krupp Stahl AG, has developedand uses an automatic blowing lancesystem, which minimises the times re-quired for lance changing.
The characteristic features of the systemare a coupling bell integrated into thelance carriage and equipped with fixedmedia connections, and a specially con-figured coupling head on the lance.
Quick lance changing is ensured by amanipulator, which is arranged oppositethe blowing lance and which accepts anew lance before the changing operation.
For instance, lance changing in the oxygen steelmaking shop of Ispat takes10 minutes on average.
A C-hook can be used for lance removal and installation where structural steelspace restrictions do not allow the instal-lation of a manipulator.
Eroded nozzles. Lance tip.
13
Lance quick-changing rig at the Ruhrort Ispat works.
Illustration of quick-changing rig.
Chemical reactions. �
SteelmakingSMS DEMAG
14
SLAG SPLASHING and BOTTOM STIRRINGSLAG SPLASHING and BOTTOM STIRRING
SLAG SPLASHING
Constant efforts at improving vessellining service lives have resulted in anumber of new developments, such aschanges in the chemical composition of the bricks and the coating of the bricklining with residual slag, which havefinally led to the present and widelyadopted Slag Splashing method.
This method means that a sharp jet of nitrogen is blown onto the slag thatremains in the converter vessel aftersteel tapping, to the effect that slag issplashed onto the converter vessel walls,adheres to the brickwork and forms aprotective layer on the refractory lining.
Slag adherence is significantly influenced by the chemical composistion and thewear resistance of the brickwork. Addi-tionally, the consistency of the slag playsan important role in this technique.
In general, the melter visually judges thecondition of the slag and decideswhether lime or dolomite should beadded to obtain the desired consistency.Appropriate process automation is anoth-er method of achieving the required slagcondition. The tests carried out duringthe past few years, chiefly in the USA,show that the service life of a vessel lin-ing on which slag splashing is additionallyemployed ranges between 10,000 and20,000 heats.
The nitrogen jet is injected by means of the existing oxygen lance, which isconnected to a separate nitrogen controlloop for the purpose. The lance traveldistance is adapted accordingly to enablethe lance to be lowered deeply enoughinto the converter vessel.
Slag splashing illustration.
Illustration of bottom stirring system.
15
STIRRING THROUGH THE
VESSEL BOTTOM
Bottom stirring in converter vessels wasdeveloped in the late seventies/earlyeighties. Steel bath agitation in a BOFvessel is chiefly produced by the energyinput of the jet of oxygen which hits thebath surface and by the energy of boil-ing, assisted by the formation of CO.CO formation is high during the main period of decarburisation in the jet im-pact area and in its immediate vicinity onthe bath surface. Dead zones, where the reaction potential is lower, exist in themarginal surface regions.
To achieve homogeneity of composition and temperature uniformity in the melt, it is expedient to inject inert gas, eitherargon or nitrogen, through the vesselbottom into the melt. The injected gasimproves bath agitation and conveys thecarbon to the oxygen impact area duringphases of low CO formation. The amountof injection gas varies in accordance withthe different phases of the steelmakingprocess. The amounts of iron containedin the slag are significantly reduced andhence the overall yield of the converter isimproved.
An additional crucial consideration inmodern process technology is a lowphosphorus content of the melt at theend of blow. The injection of stirring gasthrough the bottom during the steel-making process and post-stirring at theprocess end significantly contribute toachieving this aim. Special tuyeres whoseflow rates are separately variable are employed for the introduction of oxygenand inert gas.
Argon
ArN2
Nitrogen
Converter 2
Converter 1
Converter 3
Tuyere bricks.
P & l diagram.
Converter vessel bottom with media piping.
SteelmakingSMS DEMAG
16
SUBLANCESSUBLANCES
Steelmakers have been quite familiar withsublance technology since the eightiesand have been using it as an integral partof automatic oxygen steel production.Nevertheless, SMS Demag sees furtherpotential for production enhancementand quality improvement in this field.
The use of industrial robots for probehandling has significantly shortened theintervals between successive measure-ments at the end of blow. The highmemory capacity of present-day robotcontrol systems makes it possible to task the robot with a variety of functionswhich positively influence the entireprocess sequence in respect of sample-taking and sample evaluation. One exam-ple is the Complete Ad-Hoc Analysis ofmelt samples taken with the help of asublance.
A system developed by SMS Demaguses a laser-based analyser to render itpossible to analyse within a minimum of time those elements which are mostimportant in the course of production.Upon extraction from the converter, theprobe tube is pulled by the robot fromthe sublance and conveyed to a sever-ing station where the sample is cut offwhile still inside the cardboard tube of
the probe. After this, the robot takes the probe with the cut face of the half-sample to the laser analyser. Contrary tothe conventional sample-analysis method,this technique does not require any spe-cial sample preparation for analysis.
The laser beam creates plasma on thecut surface of the sample. A spectrome-ter uses the radiation from the plasma todetermine the chemical analysis of theheat. Differences in the wave lengths ofthe plasma radiation from the individualelements indicate the amounts of car-bon, chromium, manganese, aluminium,cobalt, copper, molybdenum, nickel,phosphorus, sulphur, silicon, and titaniumcontained in the steel.
Reductions of up to seven minutes intap-to-tap time can be achieved throughthe use of this new technology, com-pared with the previous standard practiceof sample unpacking, sample dispatchingthrough a pneumatic tube system to thecentral laboratory, sample preparation,and spectral analysis.
Robot and laser analysis.
General view of sublance installation.
17
Fe II 201.0 nm
Fe II 193.2 nm
192 194 196 198 200
Wavelength/nm
Carboncontent:
1.527%
1.052%
0.611%
0.302%
0.048%
0.019%
Norm. Int. / a. U.
C I 193.1 nm
*1E4
6.00
4.00
2.00
0.00
Typical spectral lines.
Sublance in measuringposition; robot in waitingposition.
Robot with gripper.
SteelmakingSMS DEMAG
18
WASTE GAS ANALYSISWASTE GAS ANALYSIS
Waste gas measurement is now an inte-gral part of most process control systemsin oxygen steel production.
In addition to a static model for the pre-diction of process events, waste gasmeasurement allows continuous obser-vation and control of the process in a dynamic model provided in conjunctionwith the sublance system.
The decrease in the decarburisation ratetowards the end of blow indicates whensublance measurement should be per-formed. It is thus possible to reliablyachieve the carbon content and the tem-perature target. The calculation of iron,manganese, phosphorus and sulphurslagging on the basis of the oxygen bal-ance makes it possible to tap and alloymost of the heats without having to takea random sample and await its analysisresults.
The rate of chromium combustion can beobserved by continuous analysis of thewaste gases and by automatic interven-tion in the blowing process. This is highlyimportant in respect of chromium slag-ging, above all in special steel productionin the MRP/AOD converter.
When decarburisation is nearing its end-point, the rates of oxygen and inert gasflow through the top blowing lance andthrough the bottom tuyeres can be con-trolled to meet the oxygen requirementas the decarburisation rate declines.
Waste gas analysisCO, CO2, O2
Infrared measurement
Waste gas flow
Vent.-deviceRestr.-deviceThermodyn. corr.
Weak points
– Time delay (30–40 s)– Add. measurements
for thermodyn. corr.– Waste gas flow
measurement– Only C- and
O2-balance
Dynamicprocessmodel
O2, T, PCO control
fromO2 and
E-balance
C, Cr, T,
dC dCr dT– – –dt dt dt
Weak points
– Time delay (30–40 s)– Appear until high
Ar flow– Short maintenance
interval (1–2 weeks)
– Only C- andO2-balance
Waste gas flow
Indirect fromtracer gas flow(Ar, He)
Waste gas analysisCO, CO2, O2, Ar,N2, H2, He
e/m – Measurement
Mass spectrometry
Conventional measurement
�( )( )( )
Waste gasMain pipeline
Waste gas analysis
CO CO2 O2
0.0% 0.0% 0.0%
Response time:0.5 s 0.5 s 0.5 s
Waste gas sample
Delivery pumps
Vol. approx. 0.5 l
Transport time: 2 sPreparation time: 23–26 sResponse time: 1.5 s
Delay time: 26.5–29.5 s
Restrictiondevice
Waste gaspreparation
Waste gas pipeline
Gas cooler
Coarsefilter
Dry finefilter
Processor
Waste gassample
Pressureconverter
Main pump
Measuringhead
Turbomolecularpump
Waste gas inlet Test gas inlet
� Waste gas analysisusing mass spectrometer.
Diagram of wastegas analysis.
Waste gas analysis usingindividual components. �
19
SONICMETERSONICMETER
Sound level measurement during steel-making in a converter serves to monitorthe formation of slag during the blowingoperation in order to simplify productionand augment the yield of the process asslopping (boiling over) is avoided.
During blowing, the sound level is in-fluenced by
slag formation during silicon removal,CO formation starting when maindecarburisation begins,CO formation declining at the end ofmain decarburisation.
The sonicmeter method, using an enve-loping curve, represents the containmentof the standard curve of the sound levelwithin a minimum/maximum designrange. This containment is monitored bysoftware specially developed for the pur-pose. Any overshooting or undershootingof the limits corrects the position of thelance and influences the formation ofslag.
The lance is lowered if the slag volumein the converter vessel is excessive. Thelance is raised if the slag volume is insuf-ficient. Reliable determination of the opti-mum frequency band for measurementof the sound level is contingent uponpreliminary testing of the noise emittedduring converter blowing. The tests areintended to make certain that no noisefrom external sources in the vicinity ofthe converter can corrupt the measure-ment results and that the requiredmicrophone is optimally positioned in thesound tube.
The use of sound level measurementallows control and adaptation of the
Si content (as an indicator of theamount of slag formed in the process)and of thedistance between the blowing lance and the bath according to changingoperating conditions.
120
110
100
90
80
70
60
50
40
30
20
10
0
Nor
mal
ized
sou
nd (
db%
)
Start window
Oxygen (Ncbm)
BloCon – Blowing control system
Sound measurement design
Expected sound level
Sound standard Sound mean varied Lower limit Upper limit
Upperlimit
Lowerlimit
Hard blowing, possible sparking
High slag development,possible slopping
Sublancemeasurement
Endpointblowing
0 1500 3000 4500 6000 7500 9000 10500 12000 13500 15000
Sound level measurement.
SteelmakingSMS DEMAG
20
AUTOMATIONAUTOMATION
Automation during the manufacture ofsteel is no longer confined to processcontrol and process monitoring.
Ever more stringent customer demandsfor optimum steel grades and cost-effective steelmaking make it necessaryto employ systems which optimise theprocess as a whole and the processevents.
The systems are structured hierarchicallyas follows:
Level 0 – Field equipmentLevel 1 – MSR equipment, including visualisationLevel 2 – Process optimisation bymeans of process modelsLevel 3 – Production planning andmanagementLevel 4 and higher levels – Administrative functions
The SMS Demag automation systemsare able to cover all these needs. TheBloCon model is available on Level 2 forsteelmaking by the BOF process. TheBloCon model is based on the metallur-gical description of the blowing processof a BOF converter. It calculates themass and the thermal balance with thehelp of an optimisation algorithm.
The design of the model enables thecalculation of all charging materials con-cerned. BloCon supports all technologiesapplied to a modern BOF converter, suchas bottom stirring, sound measurement,offgas analysis, and the use of sublancemeasurement.
To mainframe and laboratory
Main control room Engineering station
Converter Lance Sublance Materials Cooling Day bins Dedusting
Lime5040
Ore 21136
Dolo224940
Dolo342850
Dolo342850
Sublance
Main lance
Dolo221081
Dolo341080
400
350
300
250
200
150
100
1200
1000
800
600
400
200
0
Lanc
e he
ight
ove
r ba
th in
cm
500
450
400
350
300
250
200
150
100
50
0
Lanc
e he
ight
ove
r ba
th in
cm
Stir
ring
gas
in N
m3 /m
inO
xyge
n flo
w r
ate
in N
m3 /m
in
0
0
10
8
6
4
2
04000
Sublance inblowmeasurement
Lance heightover bath
Bottom stirringNitrogen Bottom stirring
Argon
Blowing end
Argon flow rate
Oxygen blowing rate Sublance measurement
Nitrogen flow rate Lance height
Oxygen in Nm3
8000 12000 16000 20000
120
Blowing time in secs
240 360 480 600 720 840 960 1080 1200
a)
Example of an integratedautomation system Level 1 + 2.
Typical blowing pattern.
21
SMS Demag also offers the SecMetmetallurgical model, which was devel-oped for the production of special steelsin AOD/MRP converters and which cov-ers the particular needs of low-carbonaustenitic and ferritic steels.
Statistics reflecting heat data, tappingtemperatures, analyses, material con-sumption, etc., must be created and mustbe retrievable without delay to enable thequickest possible reaction to changingconditions.Customer specific require-ments in connection with steel gradesand lot sizes necessitate a higher produc-tion planning level to enable individualprocess events and the sequence ofmelts to be controlled. This encompassesall steps, from the supply of hot metal tothe sequence of conticasting ladles.
As a valuable aid for this purpose, SMSDemag offers a production planning andcontrol system (PPS), which has beenspecially developed for such steelmakingdemands.
It forms part of the company-wide man-agement and information system and hasinterfaces with Sales, Procurement,Material Practice, Logistics, and the subor-dinated Level 2 process computer sys-tems. On the basis of sales planning andcustomer orders received for finishedproducts, it is the objective of productionplanning and control to coordinate andmanage production in all steelmaking andsteel rolling areas for the purpose of ob-taining, within specified time scales, thetonnages and grades agreed with the cus-tomer.
SteelmakingSMS DEMAG
22
AUTOMATIONAUTOMATION
CUSTOMER BENEFITS:
The benefits of a production planningand control system are reflected in thefollowing:
Production consistent with orders(even for small lots),Production for just-in-time delivery,Flexibility with regard to short-term orders,Satisfaction of the customers’ qualityrequirements in the melt, casting androlling sequences,Coordination of events in the melt-shop to permit long conticasting sequences,Efficient personnel assistance in theelimination of malfunctions.
The orders (melts) to be processed in asteel plant are plotted in a Gantt diagram.The diagram includes all processingstations (converters, alloying stations andcontinuous casting facilities) with speci-fied sequences and processing times.
The diagrams are updated dynamicallyby the process status messages fromthe Level 2 systems. The central coordi-nating function is able to intervene man-ually to change schedules and start newplanning computation runs.
Without flexible automation it is, fromthe present point of view, hardly possibleany longer to produce steel economicallyin conformity with today’s stringent quali-ty requirements.
Scheduling system. Production planning.
23
SLAG RETAINING SYSTEMSLAG RETAINING SYSTEM
Steelmaking process slags generally serveto absorb unwanted tramp elements, sta-bilise non-metallic inclusions segregated inthe melt, and prevent radiant heat loss fromthe molten metal. Slags having specialproperties are indispensable within specificprocess steps. However, any such slag en-trained to the next process step will notonly delay subsequent progression but willalso result in a production cost increase.
The SMS Demag slag retaining system em-ploys specially developed floating plugs aswell as ultrasonic and/or laser-based mea-suring methods. These floating plugs delaythe formation of the outlet whirl and auto-matically close the taphole.
The equipment serving to insert the floatingplug is arranged on the converter floor nearthe vessel, either mobile, suspended, orslewable, depending on the space situation.
Slag retaining device, suspended type, mobile type and slewable type.
Slag retaining device, inserting the floating plug.
SteelmakingSMS DEMAG
24
CONVERTER RELINING
EQUIPMENT
SMS Demag offers different convertervessel relining systems. Either a platformis lowered down into the vessel by meansof rope winches in the case of integralbottom converters or, in replaceable bottom vessels, the working platform is introduced from below by means of hydraulic jacking cylinders and/or a spin-dle drive.
The relining bricks are lifted by means of a hoisting cage in the middle of thedevice. Robots serving to facilitate vessel rebricking are being developed.
VESSEL BOTTOM JACKING
DEVICE
The removable bottoms of change-bottomconverters are lined with bottom brickson a separate stand off the converter.
Changing of the vessel bottoms, meas-uring up to 4 m in diameter and weighingup to 60 t, depending on the convertersize, is fast and easy to perform by meansof a hydraulic bottom jacking device.
RELINING EQUIPMENTRELINING EQUIPMENT
Replaceable bottom andchanging device diagram. �
Diagram of relining equipment with robot.
�
25
Converter being relined with the use of araising and lowering rebricking platformwith four-rope suspension (two rope drums).
Diagram I: Relining equipment, work-ing platform raised andlowered from above.
Jacking the bottom of an 80 -t LD change vessel converter.
Diagram II: Relining equipment, working platform raisedand lowered frombelow.
Bottom jacking devices.
Relining equipmentwith spindle drive.
SteelmakingSMS DEMAG
26
DUST COLLECTION, GASCLEANING and RECOVERYDUST COLLECTION, GASCLEANING and RECOVERY
Oxygen steel production is accompanied by considerable dust emission.
Optimised adaptation and design of the dust collecting and cleaning equipmentand possibly the use of a gas recoverysystem allow optimum operation of theoxygen steelmaking plant.
In this case also, SMS Demag offers avariety of methods and equipment tomeet this requirement.
High-performance venturi scrubbers ordry electrostatic precipitators accordingto the LT (Lurgi-Thyssen) process areavailable for the treatment of primary/process gases.
The secondary gases can be treatedeither with fabric filters or electrostaticprecipitators.
Both the Demag-Baumco system andthe LT process for gas cleaning and re-covery are capable of recovering much ofthe energy contained as carbon in themelt in the form of carbon monoxide(CO) gas during the converter process.
The recovery of the gas and the selectiveutilisation of the CO gas depreciate theinvestments required for the entire sys-tem within a very short time.
NV pH
M
V
V
Δp
NV
R
R
NV
M
T
1
2
3
Δp
T
T
P
M
VV
M M
M
T
5
7
4
6
T
Process sequence diagram:CO system� LD converter� Cooling stack with
adjustable skirt� Water-cooled hood system� Venturi scrubber tower� Fan Clean gas stack with flare Transfer station� Gasometer
27
NV
P
T8
SteelmakingSMS DEMAG
28
ERECTION ANDCOMMISSIONINGERECTION ANDCOMMISSIONING
The range of supplies and services whichwe offer is complemented by the erec-tion and commissioning of individualsteel mill modules up to and including in-tegrated turnkey plants.
Our planning offer refers both to pre-liminary assembly and to the completeerection work and allows for country-spe-cific infrastructures, local manufacturingfacilities, and the availability of qualifiederection personnel.
Erection inspectors and chief erectorswith international experience can bemade available for supervision and forensuring qualitatively perfect perfor-mance within agreed time scales.
Our metallurgists supply technical know-how of worldwide reputation during thecommissioning of the equipment.
Erection of MRP-L converter with secondary dust collection and lance equipment.
Preassembly of a 300-t converter. Transport of a completely
preassembled 300-t converter.
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MRP-L converter with partially installedenclosure and ladle transfer car under the converter floor.
SteelmakingSMS DEMAG
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SMS DEMAG CONVERTER EQUIPMENTSMS DEMAG CONVERTER EQUIPMENT
Dust collection, gas cleaningand gas recovery systems.
Bottom stirring systems.
Sublance systems.
Oxygen blowinglance systems.
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Converters.
Change-vessel converter systems.
Slag retaining devices.
Bottom jacking and converterrelining equipment.
SMS DEMAG AG
Steelmaking and Continuous Casting Technology Division
Eduard-Schloemann-Strasse 440237 Düsseldorf, Germany
P.O. Box 23 02 2940088 Düsseldorf, Germany
Phone: +49 (0) 211 881-4316Telefax: +49 (0) 211 881-4841
E-mail: [email protected]: www.sms-demag.com
MEETING your EXPECTATIONS
H2/
301E
2000
/10/
05 .
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