STAR-CCM+ modeling of steel making

processes

Simon Lo

Blast Furnace

Basic Oxygen Furnace (BOF)

Continuous casting

Steel making processes

Blast furnace

DEM - Charging of particles

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Lifting of particles by air flow

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With heat transfer

Thermal expansion of particles

In Blast furnace, the effect of solid

expansion due to temperature may

be important

STAR-CCM+ has the capability

– Using variable density model

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Unloading of particles

Bulk flow validation

Unloading quazi-2D blast

furnace – stagnant zone

formation

Paper: Z. Zhou, H. Zhu, ISIJ

Vol 45, 2005

STAR-CCM+ results in

agreement with both

experiment and independent

code results

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Analysis of volume fraction distribution

– Predicted the amount of load lifting after staring injecting air

Computation time for a million particles is getting close to

reasonable

– 1,003,146 particles

– Simulated 0.2 seconds of physical time

– Took ~48 hours on 96 cores

– Used DEM timestep ~ 5.3E-6 s

Summary of coupled DEM-CFD BF simulation

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Eulerian multiphase model

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• Full size furnace:

• 25m height

• 7.2m hearth diameter

• 2D axisymmetric model

• Multi-component Eulerian phases:

Gas phase: CO, CO2, N2

Solid phase: Ore, Coke, Fe, Fe2O3, C

• Two reactions:

Fe2O3 + 3CO -> 2Fe + 3CO2

C + CO2 -> 2CO

Temperatures

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Fe/Ore mass fractions

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CO/CO2 mass fractions

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Basic Oxygen Furnace (BOF)

Oxygen is blown onto

the metal bath to

oxidize elements such

as silicon and

phosphorous.

Due to strong stirring

inside the vessel

oxides are transferred

from metal to slag.

Liquid steel is pour from converter

to ladle through taphole.

Dart designed to float at interface

between steel and slag.

Near end of tapping, dart is sucked

into the taphole blocking the flow

and limit slag carry-over into the

ladle.

Basic Oxygen Furnace (BOF)

Converter in tapping

position

Dart sucked into the taphole

Continuous casting of steel

Continuous casting of steel

Continuous casting of steel