Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
K1-MET
Competence Center for Excellent Technologies in Advanced Metallurgical
and Environmental Process Development
Area 4 – Valuation and Optimization of Metallurgical Raw Materials
CFD Simulation of Co-Injection of Plastic
Particles and Oil into a Blast Furnace Raceway
Christian JORDAN, Christian MAIER, Michael HARASEK
Christoph FEILMAYR, Stefan SCHUSTER (voestalpine Stahl, Linz)
michael.harasek@tuwien.ac.at
Achema 2012
Institute of Chemical Engineering
page 1
Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
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Optimization of the operation conditions and
maximization of plastics injection rate
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(voestalpine Stahl GmbH, Linz)
Detailed CFD-modeling of the blast furnace
raceway
Determination of fluid dynamic properties
Investigations of the reaction kinetics of different
auxiliary reductants
Maximum plastic injection capacity 220.000 t/a
Startup in June 2007 (test operation since 2006)
Input material processed waste plastics
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Blast Furnace HO A
Pellets, agglomerates from mixed plastics fractions
(municipal and industrial waste)
Granulate from shredder residue treatment process
Region
observed
Flexibility in injection
Pellets, agglomerates and granulate
Achema 2012
Institute of Chemical Engineering
page 2
Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
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Turbulence
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Radiation
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Global and heterogeneous reactions (9 gas-phase species, coke)
Eddy Dissipation Concept (Magnussen)
DPM – Discrete Particle Model
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Discrete Ordinates Model (DOM)
Absorption coefficients estimated with the
„Weighted Sum of Grey Gases“ (WSGG)-approach
Reaction
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SST-kω-Model by Menter or realizable ke-Model
Lagrangian particle tracking, coupled to fluid phase via source terms
Plastic particles – radiation interaction + decomposition
Heavy fuel oil multicomponent droplets - pyrolysis
UDF – User Defined Functions to extend CFD code
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Raceway formation and coke bed porosity
Extended radiation model
Particle treatment (reaction, impact on raceway)
Achema 2012
Institute of Chemical Engineering
page 3
Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
 Measurements
 Construction of a small scale model of the oil lance and the tuyere based on
Reynolds analogy
 Droplet velocity (PIV)
 Gas velocity (LDA with seeding or PIV with fluorescent tracer)
 Droplet size distribution using high speed photographs
PIV image of the jet
(velocity vectors with
geometry in
background) detailed
view of the outlet
Achema 2012
Institute of Chemical Engineering
page 4
Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
 Results of CFD Modeling
Surface in tuyére level – mass fraction of carbon dioxide
Flow
direction
Raceway shape (50% porosity, blue) and hot blast pathlines entering
from bustle pipe (colored according to velocity magnitude in m/s)
Achema 2012
Mole fraction CO in the symmetry plane
Institute of Chemical Engineering
page 5
Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
 CFD Model Development
 Heat transfer due to convection, thermal
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velocity magnitude with path lines
conductivity and radiation
[mm/s]
coke bed
Effects of material properties of fluid phase
2.5
Solid phase material properties & porosity
2.0
Coupling without using Eulerian model
1.5
Implementation of heterogenous reactions
1.0
(coke bed – surrounding gas phase)
Validation of the new method using
0.5
systems of various complexity
0
solid
phase
grid
transfer terms
phase
boundary
[m/s]
20
gas flow
16
gas
phase
grid
12
8
4
0
Achema 2012
Institute of Chemical Engineering
page 6
Thermal Process Engineering
Plastic Particle Injection into Blast Furnace Raceway
Summary
 Measurement (PIV) and modeling of fuel oil droplet size distribution
 Characterization of the pyrolysis of waste plastic particles
 Implementation of new modeling approach: Dual Grid
 Successful validation of CFD-model by comparison with
experimental data
 Implementation of UDF in full-scale blast furnace
Further Work
 Further development of the Dual Grid Method - CFD-Calculations for
different operating conditions
 Co-injection of particles and fuel oil
 Additional high speed imaging for validation of spray modeling
Achema 2012
Institute of Chemical Engineering
page 7