A CFD Study of Particle-Laden Flow of a Tundish Water-Model

Transcription

1 CONTENT A Study of Particle-Laden Flow of a Tundish Water-Model Dipl.-Ing. (FH) Eike Runschke M. Sc. Gerold Haskamp Dr. rer. nat. Zeljko Cancarevic MBA Dr.-Ing. Henning Schliephake

2 Content CONTENT Company Market and Products Technology at Georgsmarienhütte GmbH

3 History COMPANY 1856 Founded as an iron production plant located in the South of Osnabrück. Its name derived from the last rules of the Hannover dynasty, King George V. and Queen Marie Klöckner acquires Georgsmarienhütte Dr. Großmann and Drueker & Co. GmbH buy and incorporate GMH The blast furnace-converter was replaced with a DC electric arc furnace Georgsmarienhütte Holding GmbH was created A new walking-beam furnace replaces both of the 40+ year old walking-hearth furnaces A second ladle furnace is installed to expand secondary metallurgy Various modernization of furnace, rolling mill and finishing shop.

4 Company COMPANY Manufacturer of quality and engineering steels Market leader in Germany Among Europe s top manufacturers Key Data 2012: 644 mil. Euro Turnover to rolled products 1,334 employees

5 International offices COMPANY

6 Our Vision COMPANY BEING PROMPT Melt and treat in the morning Cast at noon Roll in the evening Finish over night MEANS REACTING WITH MAXIMUM PRECISION IN THE SHORTEST TIME POSSIBLE. CHALLENGE US! Ship the next day!

7 Market Our steel drives you forward MARKET Powertrain, engine, transmission, steering and chassis components of cars and trucks End use of 80% of our products in the automotive industry

8 References MARKET

9 DC electric arc furnace 130 MW TECHNOLOGY

10 TECHNOLOGY

11 at Georgsmarienhütte GmbH Wide field of application due to different production processes since August 2011 Until now: Heat transfer, air/water flow as well as particle-laden multi-phase VOF Hardware & OS: Workstation: Windows 7 64bit, 8 cores, 3.6 GHz, 48GB RAM Workstation: Windows 7 64bit, 4 cores, 4.9 GHz, 32GB RAM Cluster: Windows Server 2008 R2, 192 cores, 2.4 GHz, 24GB RAM / node Cluster: Linux Red Hat, 192 cores, 3.3 GHz, 64GB RAM / node HPC Cluster Manager

12 Air flow Analysis of an axial fan Steady and unsteady, rigid body motion Comparison with measured data

13 Air flow Simulation vs. measured data 10 [m/s] 15 [m/s] 20 [m/s] 25 [m/s] [ ] 30 [m/s]

14 Multiphase VOF Tundish Water Model vs. Particle-laden flow of 6-strand tundish Comparison of simulation with scaled water model Simulation: VOF (water and air), non-metallic inclusions = lagrangian particles of different size and density Water model: 1:4, 20 C, Froude-similarity, particles = glass hollow spheres Investigated time = 20 minutes

15 Water Model ball valve shroud, adjustable in height 1:4 scaled tundish model made of sheet acrylic glass filter, connected to submerged nozzle movable support frame

16 Water Model usb-hub power distribution surge drum with pump frequency controlled pump flow sensor

17 Water Model injection device for dye and particles point of injection, in front of the shroud connection to in-tank pump

18 Water Model Example of the distribution of dye Example of the size of fractionated particles

19 Water Model Calibration nominal effective error a known mass of glass-sheres were put into the filters and the system was flushed analysis of difference values analysis of influencing factors reduction of error sources fractionation of the glass-spheres sealing the filters with Vaseline increase of inserted particles

20 Water Model Calibration error sources leaking filters accuracy of laboratory scales mass loss of filter element after 100 C residue of Vaseline mass of a single glas-sphere unattended flow rate of the strands ± g g g + + U = uncertainty K = correction factor K = 2 assumption that 95% of measured data is correct

21 Water Model influence of sealant at the filter elements and increace of mass of particles no sealant at filter element

22 -Simulation k- SST Mesh: Trimmer, Prism Layer, 3 mio. volume cells Fluid: Eulerian Multiphase, Particle: Lagrangian Multiphase Particles: 100 to 200µm, density 0.65 to 1.24 g/cm³ Strand 1 to 6: mass flow inlet with identical flow Solution time 0 300s: creation of fluid flow Solution time 300s, 600s, 900s: injection of 1000 particles of every size Solution time 1500s: end of simulation Particles that left the system are counted

23 -Simulation Time step = 0.025s point of injection 8 inner iterations definition of injected particles velocity of point of injection

24 -Simulation definition of water and air definition of mass outlet definition of particles definition of mass inlet

25 -Simulation Reports of Lagrangian Phases in order to count all particles within the system Reports of Particle Tracks in order to detect all particles which left the system These Reports will later be used in order to count particles at the six outlets

26 -Simulation Sum of Report: Element Count The previously created reports are used in order to count particles at the six outlets

27 -Simulation vs. Water Model Solution Time = 1500s Density [g/cm³] Diameter [µm]

28 -Simulation vs. Water Model same pattern big difference of relative value Ø = 110µm = 1.24 g/cm³

29 -Simulation vs. Water Model different pattern huge difference of relative value Ø = 200µm = 0.65 g/cm³

30 Conclusion Simple equipment can generate huge knowledge Density and diameter of glass-spheres are hard to determine Glass-spheres are not homogeneous and tend to break to pieces Significant difference of experimental data compared to : huge influence of density and diameter of the particles : sensitivity analysis is needed : fine-tuning is needed in order to a closer match to the water model

31 Outlook Tundish vs. Water Model better measurement technique study on built-in components study on casting-speed fine-tuning of -Model comparison to real tundish improvement of real tundish

32 Outlook Tundish vs. Water Model Ladle

33 Outlook Tundish vs. Water Model Ladle Ingot Casting

34 Outlook Tundish vs. Water Model Ladle Ingot Casting Continuous Casting Source: Brian G. Thomas, University of Illinois at Urbana-Champaign

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