jsw casting equip
TRANSCRIPT
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A K KarandeSMS II , CCP Operation
1
Continuous casting equipment and its functions
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A K KarandeSMS II , CCP Operation 2
LadleTurret
Ladle
Tundish Car
Mould
Top Zone
Bender
Segments
Straightener
Cut Off
Discharge
Tundish
Mould Oscillation
Dummy Bar
Continuous casting equipment
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A K KarandeSMS II , CCP Operation 3
Ladle Turret
Funct ion: -
Supports the Ladle in Casting Position.
Usually Fitted with Lift/Lower Armsfor Ladle Covers
Allows Exchange of Full and Empty
Ladles
Allows Sequence Casting
Allows Emergency Rotation
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A K KarandeSMS II , CCP Operation 4
Shroud manipulator
Funct ion:
Shrouding manipulator holds the refractory shroud
Protect the ladle stream and avoid the air ingress
Avoid re-oxidation of the steel
Perform submerged opening
Helps to detect the slag entry with slag detector fitted on arm
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A K KarandeSMS II , CCP Operation 5
Tundish car
Funct ion:
Supports the Tundish.
Allows Transport of the Tundish from Pre-heat to Casting Position.
Allows Lift / Lower and Alignment of the Tundish SEN wrt mould.
Allows Exchange of Tundish during Sequence Casting.
Allows Emergency Removal of Tundish.
Tundish car
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A K KarandeSMS II , CCP Operation 6
Tundish
Function: -
Provides a Stable Controlled Liquid Steel Feed to the Mould.
Ability to act as a reservoir during ladle changeover
Distribution of flow between strands
Provides a Uniform Steel Temperature to Each Strand.
Allows Floatation of Inclusion for Cleaner Steel.
Must Minimise Heat Loss from Liquid Steel During Casting. (usingtundish powder layer and tundish lid)
Weirs
Dams
Tundish PowderTundish Lid
Ladle Shroud
Tundish to Mould Shroud
minimum residence time = 7 - 8 minutes
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7/23A K KarandeSMS II , CCP Operation7
Tundish Pre heaters
Funct ions: -
Moisture removal in tundish.
Avoid freezes of first incoming steel of the cast.
Avoid SEN choking during start of cast.
Maintain ideal super heat in tundish.
Avoid thermal shock to pouring refractory.
Ladle to tundish temperature drop minimized.
Smooth start of casting.
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8/23A K KarandeSMS II , CCP Operation 8
Mould
It serves as:
A heat exchanger that handles a very high heat flux(>1 mw/m2).
A solidification device that builds up a thin solid shell.
A Die which gives its shape to the product without tearing the brittle shell.
A Chemical reactor with a huge through put which separate liquid steelfrom non-metallic.
The continuous caster mould performs several diverse functions in a
integration fashion
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9/23A K KarandeSMS II , CCP Operation 9
Heat transfer in mouldHEAT TRANSFER IN CONTINUOUS CASTING
Conduction through the solid shell
Heat transfer in the mould is
controlled by using casting flux:
Conduction through the copper
mouldConvection through the mould
cooling water
Solidification (Latent heat evolution
in the mushy zone)
Convection of liquid super heat to
the shell surface
The size and properties of the
interface between the shell and the
mould
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10/23A K KarandeSMS II , CCP Operation 10
Mould coolingHEAT TRANSFER IN CONTINUOUS CASTING
Mould water transfers heat from the solidifying shell
Mould cooling water flow, velocity and pressure is designed to
prevent both boiling and control the mould copper temperature.
Mould cooling should be as even as possible around the
circumference of the mould.
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11/23A K KarandeSMS II , CCP Operation 11
Break out prediction and Thermal mapping
Task
Solution Measured value of relevant processinformation
Evaluation of signals under
consideration of different process
situation
Data storage and management for
analysis of critical operating conditions
Prediction of stickers and reduction
of break-out rate
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12/23A K KarandeSMS II , CCP Operation 12
Mould oscillator
Mould oscillator is necessary to:
Minimize friction between mold plates & steel shell
Sticking of the solidifying shell
Avoid shell tearing
Avoid liquid steel break outs
Osci l lat ion Systems:-
Electro-mechanical (CC 1&2).
Hydraulic (CC 3)
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13/23A K KarandeSMS II , CCP Operation 13
Conventional Mould with Four Cam Oscillator
Fixed mould stroke
Sinusoidal wave formonly
Frequency varies directly
with casting speed
CC
1 & 2
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A K KarandeSMS II , CCP Operation 14
Hydraulic Mould oscillator (CC-3)
Decrease of depth of oscillation mark
Increase of mould powder consumption
Decrease of frictional force between
solidified shell and mould-2
-1
0
1
2
Normalized Time
Stroke[mm
] SinusoidalNon-Sinusoidal
50%70%
Automatic mould water
connectionsBendersupport
Leaf spring
guiding
system
Mould fixation unit
Mould
centering
Weight
compensator
Mould table
Effect of non -sinu so idal osci l lation
Variable mould stroke
Sinusoidal and Non
sinusoidal wave forms
Variable frequency.
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A K KarandeSMS II , CCP Operation 15
Mechanism of oscillation mark formation
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A K KarandeSMS II , CCP Operation 16
Auto mould level control CC 1&2
TundishStopperRod
hydraulic-cylinder or
Electro mech.actuator
Scintilla.Counter
RadiationsourceMold
SMS
Automat ic funct ion ing of cast ing process
Constant and precise mold level
Elimination of slag entrapments
Accuracy +/- 5mm
Improvement of surface quality
Minimization of powder usage and
inclusions
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A K KarandeSMS II , CCP Operation 17
Auto mould level control CC 3
Mould Level Controller
Control during all casting conditions
Auto start/resume cast
Accuracy 3 mm standard deviation
Backlash compensation
Clogging prevention (vibration,
knocking)
Actuator Electric actuator Electromagnetic
Measurement Stopper rod
Flow Control
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A K KarandeSMS II , CCP Operation 18
Strand support
Slab caster Bloom caster
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A K KarandeSMS II , CCP Operation 19
Function:
Plug the mould and enable start of casting.
Initiate withdrawal of the strand.
Controls withdrawal until the strand enters the drive rolls.
Types:
Top fed - used on high production casters - expensive option.
Bottom fed - used on low/medium production casters - cheaper option.
Restranding Times:
Top fed - 25 minutes minimum.
Bottom fed - 45 to 60 minutes.
Dummy bar and systems
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A K KarandeSMS II , CCP Operation 20
Secondary Cooling Options:- Water only.
Limited turndown.
Used for less demanding steel grades.
Limited cooling capacityIncreased nozzle blocking tendency.
Air mist.
Increased turndown.
Used for all steel grades including critical grades.Increased cooling capacity (maximum K-factor > 30 [slab casting]).
Reduced nozzle blockage tendency.
Secondary cooling system
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A K KarandeSMS II , CCP Operation 21
Speed tie contro l ( level 1 PLC)
Zone water flows vary directly with changes in casting speed.
Dynamic contro l (level 2 Compu ter)
Zone water flows vary with respect to the age of the strand
contained within each cooling zone.
Secondary cooling control system
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A K KarandeSMS II , CCP Operation 22
Speed Tie Control
Zone Water Flow
Casting Speed
Time
Speed/WaterF
low
Time
Speed/WaterF
low
Casting Speed
Zone Water Flow
Effective Zone Speed
Dynamic Computer Control
Secondary cooling control system
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A K KarandeSMS II CCP Operation 23
Time
Speed/Water
Flow
Casting Speed
Dynamic Control
Zone Water Flow
Speed Tie
Zone Water Flow
Under Cooling
Over Cooling
Comparison of cooling systems