Upload
esmond-parker
View
214
Download
0
Tags:
Embed Size (px)
Citation preview
Numerical Modelling of Ingot Numerical Modelling of Ingot Charging Configurations at Charging Configurations at
Pro-Tec CGL2Pro-Tec CGL2
J.R. McDermid, Noranda Inc. - Technology
B.M. Maag, Pro-Tec Coating Co.
M. Gaug, Maya Heat Transfer Technologies
94th Galvanizer’s Association Meeting
Dearborn, MI
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 2
Outline
IntroductionNumerical Model DetailsResults and Discussion
• General Observations
• Detailed Case ResultsConclusions
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 3
Introduction
Numerical and physical modelling has evolved to become a powerful tool for understanding the factors which control and can alter flow in the CGL bath• many papers presented on this subject at the GA,
Galvatech and other conferences
Solutions now encompass the coupled thermally driven (buoyancy) flow as well as the strip-driven viscous drag flow• significant effect of ingot melting on the flow field in
the charging area
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 4
Introduction - cont’d
Some practical applications of numerical modelling without the thermal solution have been published• snout flow - references 9 and 11
• dross management - reference 12
Objective of the present work:• Use coupled thermal solution to determine the effect
of different charging configurations on the flow field in the Pro-Tec CGL2 bath
• Use these results to aid in the selection/specification of a new ingot charger by Pro-Tec
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 5
Numerical Modelling Procedure
Model consisted of a half-bath with a symmetry plane along the long axis of the CGL bath
Model meshing and calculation were performed at Maya Heat Transfer Technologies under the supervision of M. Gaug• further details on the methodology and calculation
boundary conditions can be found in the paper
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 6
Numerical Model Geometry
inductor
inductor
pot rolls
symmetry planesnoutingots
sink roll
steel sheet
baffle
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 7
Numerical Modelling Cases
Low Middle High
strip width 1.07m (42 in.) 1.65m (65 in).
strip speed99.1m/min(325 fpm)
137.2m/min(450 fpm)
ingot positioncentre
verticalcentre
horizontal2 offsetvertical
baffle in out
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 8
Results - General Observations
Changing the strip width/speed• minor effect on the magnitude of the flow velocities, but
not the overall fluid flow pattern
• some effect on the temperature field due to varying heat input rates, but temperature was controlled to 460ºC and overall effect was minor
Overall circulation pattern consistent with that observed by previous authors
Presence or absence of the baffle determines the shape of the overall flow within the CGL
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 9
General Flow Pattern in CGL Bath
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 10
General Observations - cont’d
There were significant differences in the flow patterns between the centreline and offset ingot charging configurations• overall flow pattern a strong function of the baffle’s
presence
For simplicity, all results presented further are for the 1.65 m (65 in.) strip at 99.1 m/min. (325 fpm) case• all velocity plots range of 0 - 0.150 m/s
• all temperature plots range of 458 - 463ºC
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 11
Results - Detailed Observations
The model visualisations were performed via 2D cutting planes at various distances from reference planes• X-Y plane parallel to symmetry plane (reference
plane)
• X-Z plane parallel to top surface plane of the CGL bath (reference plane)
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 12
VC Ingot - X-Y (0.127m) w/o baffle velocity
ingo
tpot rolls
snout
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 13
VC Ingot - X-Y (0.127m) w/ baffle velocity
baffle
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 14
VC Ingot - X-Y (0.127m) w/o baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 15
VC Ingot - X-Y (0.127m) w/ baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 16
VC Ingot - X-Z (1.270m) w/o baffle velocity
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 17
VC Ingot - X-Z (1.270m) w/ baffle velocity
inductor
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 18
VC Ingot - X-Z (1.270m) w/o baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 19
VC Ingot - X-Z (1.270m) w/ baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 20
HC Ingot - X-Y (0.050m) w/o baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 21
HC Ingot - X-Y (0.050m) w/ baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 22
OV Ingot - X-Y (1.219m) w/o baffle velocity
ingo
t
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 23
OV Ingot - X-Y (1.219m) w/ baffle velocity
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 24
OV Ingot - X-Y (1.219m) w/o baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 25
OV Ingot - X-Y (1.219m) w/ baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 26
OV Ingot - X-Z (1.270m) w/o baffle velocity
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 27
OV Ingot - X-Z (1.270m) w/ baffle velocity
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 28
OV Ingot - X-Z (1.270m) w/o baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 29
OV Ingot - X-Z (1.270m) w/ baffle temp.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 30
Conclusions The macroscopic/melting ingot flow calculated for the
Pro-Tec CGL2 bath is in general agreement with those of previous authors.
The presence or absence of the deep baffle behind the snout has the largest effect on the bath flow - when present, it effectively isolates the charging area from the remainder of the bath with communication via flow under and around the edges of the baffle.
There are only slight difference between the VC and HC charging cases - orientation factors.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 31
Conclusions - cont’d
The OV charging case is significantly different from the VC and HC cases• interaction of the descending ingot flow with the
return flow along the side walls and the rising inductor flow.
• ingot material swept along the back wall of the pot before being drawn to the snout by the drag flow from the sheet.
• overall pattern continues to be dominated by the baffle.
McDermid, Maag and Gaug: Numerical Modelling of Ingot Charging Configurations at Pro-Tec CGL2
slide 32
Acknowledgements
The authors would like to thank Noranda Inc. and Pro-Tec Coating Co. for their permission
to publish this paper.