As a result of the
intense air-water interaction in the spray nozzle, air-mist spray is one of the
most promising technologies for attaining high heat transfer. CFD simulations
and multivariable linear regression were used in the first part of this study to
analyze the air-mist spray produced by a flat-fan atomizer and to predict the
heat transfer coefficient using the casting operating conditions such as air
pressure, water flow rate, cast speed and standoff distance. For the air-mist
spray cooling simulation, a four-step simulation method was utilized to capture
the turbulent flow and mixing of the two fluids in the nozzle, as well as the
generation, transport, and heat transfer of droplets. Analysis of the casting
parameters showed that an increase in air pressure results in efficient
atomization, increases the kinetic energy of the droplets and produces smaller
droplet size thus, the cooling of the slab increases significantly. Also, a
decrease in water flow rate, standoff distance and casting speed would result
in more efficient cooling of the steel slab. The second part of the study
investigated the solidification of steel in the secondary cooling region.
Caster geometry and casting parameters were studied to evaluate their impact on
the solidification of steel. The parameters studied include roll gap, roll
diameter, casting speed and superheat. It was found that a smaller ratio of
roll gap to roll diameter is more efficient for adequate solidification of
steel without any defect. Casting speed was found to have a significant effect
on the solidification of steel while superheat was found to be insignificant in
the secondary zone solidification. The result from the air-mist spray cooling
was integrated into the solidification model to investigate the solidification
of steel in the entire caster and predict the surface temperature, shell growth
and metallurgical length. To replicate real casting process, temperature
dependent material properties of the steel were evaluated using a thermodynamic
software, JMatPro. The air-mist spray model was majorly investigated using
ANSYS Fluent 2020R1 CFD tool while the solidification of steel was studied
using STARCCM+ CFD software. Using the findings from this study, continuous
casting processes and optimization can be improved.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/17190197 |
| Date | 20 December 2021 |
| Creators | Vitalis Ebuka Anisiuba (11828069) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/NUMERICAL_INVESTIGATION_OF_AIR-MIST_SPRAY_COOLING_AND_SOLIDIFICATION_IN_SECONDARY_ZONE_DURING_CONTINUOUS_CASTING/17190197 |
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