Steel Refinement by Gas Injection Gene Baump ME447 Term Project Presentation

Argon gas Injection Diagram

What’s the Point? Increase reaction rates Reduce concentration of dissolved gases, Carbon, and Oxides Homogenous mixture in less time Benefit of using gas Injection 1.Reduction of scrapped castings 2.Less time spent on clean up 1.Better surface finish 3.Uniform material properties 4.SAVING MONEY $$

Phenomena Occurring in the Steel Bath Convective fluid flow Gas-liquid mass transfer Liquid-gas mass transfer Reactions

Turbulent Fluid Flow with Bubble Dispersion Flow pattern developed using CO 2 injection into water contained in a uniform cylindrical vessel. ( qg=83.3 × 10-6 m3/s )

Governing Equations Turbulent Fluid Flow with Bubble Dispersion

Boundary Conditions Turbulent Fluid Flow with Bubble Dispersion

Standard k – ɛ Turbulence Model Governing Equations Turbulent Fluid Flow with Bubble Dispersion

Boundary Conditions for k – ɛ Turbulence Model Turbulent Fluid Flow with Bubble Dispersion Plug into CFD program and hit solve →

Results… Turbulent Fluid Flow with Bubble Dispersion

Calculated and Observed results for the bubble dispersion zone.

Gas-Liquid Mass Transfer Model Equation used was derived by Kataoka and Miyuchi “Eddy-cell Model” Assumptions; 1.Surface renewal is made by the smallest eddy with highest frequency Governing Equation

Gas-Liquid Mass Transfer Model Calculated and observed results for the volumetric Mass-transfer coefficient at the free surface. Where the open circles represent the observed values.

Gas-Liquid Mass Transfer Model Finally, the mass transfer coefficient at the bubble dispersion may be determined by equation 20.

Gas-Liquid Mass Transfer Model The calculated and observed values for volumetric mass-transfer coefficient in the bubble dispersion zone. The open circles represent the observed values.

Conclusion Successful in determining flow pattern, velocities, and gas hold-up distribution at the plume, surface, and throughout the vessel. Returned reasonable results for the volumetric mass-transfer coefficient at the surface and in the bubble dispersion zone. The overall mass transfer model returned larger values than those observed. This is a result of assuming an axisymmetric surface agitation. In fact it fluctuates and causes more energy dispersion than accounted for.

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