Metal founding – Process – With measuring – testing – inspecting – or condition determination
Reexamination Certificate
2001-04-24
2003-04-08
Dunn, Tom (Department: 1725)
Metal founding
Process
With measuring, testing, inspecting, or condition determination
C164S154700, C164S485000
Reexamination Certificate
active
06543519
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a continuous casting mold.
2. Description of the Prior Art
The continuous casting molds known to the art, whether configured as multi-station molds such as, for example, the “twin roller” pursuant to a 19
th
Century Bessemer patent, or as a single-station mold, are comprised of a copper wall, which is cooled from the back with water via a water distribution chamber.
The state of the art and its shortcomings (as depicted in FIG.
1
), are illustrated in the following using the example of an oscillating single-station mold (
1
), whereby preferably steel using a SEN or submerged entry nozzle (
2
) and casting powder (
3
) or casting slag (
3
.
1
) is cast into slabs or ingots having a thickness of between 150 and 30 mm and a maximum width of up to of 3.300 mm at a casting velocity (
4
) of up to max. 15 m/min.
Conventionally, such a mold is supplied with water cooling of, for example, 4,000-8,000 L/min with a strand [casting] width (
5
) of 1,600 mm and at a pressure of between 5-15 bar, whereby said water cooling is constructed in such a manner that the water temperature T
M
in
at the mold inlet (
6
) is held constant independent of
casting velocity (
4
),
casting width (
5
),
thickness of the copper plate (
7
),
casting powder (
3
),
casting slag (
3
.
1
),
water pressure (
9
) and
oscillation (
12
).
As casting velocity increases, the mold coolant water (
10
) accrues a higher temperature T
M
out
(
11
). The temperature difference (
13
) between the constant inlet temperature (
16
) and the variable outlet temperature (
11
) is a function of the aforementioned constraints. If, for example, the system is considered under the assumption that all constraints, save for casting velocity, are held constant, then, with increasing casting velocity from VC
1
(
4
.
1
) to VC
2
(
4
.
2
) the outlet temperature (
11
) or the temperature difference (
13
) and consequently the mold skin temperature (
14
), increases from T
1
(
14
.
1
) to T
2
(
14
.
2
) as does the energy under the energy lobe [sic] (
15
) from (
15
.
1
) to (
15
.
2
).
Consequently, with changing casting velocity (
4
) and with the variation in the aforementioned constraints, the ‘hot-face’ temperature (
14
) changes, resulting in constantly varying lubrication of the strand shell (
16
) and thermal flux (
17
) in the mold, whereby said variations in casting conditions result in perturbations of the casting process and in the surface of the strand.
Continuing with the description of the water circuit, the water then is cooled to a desired constant inlet temperature (
6
) in an output controllable heat exchanger (
18
) and the water is re-directed to the mold under a preset pressure (
9
) with the aid of a pump station (
19
). Moreover, at high casting velocities of 10-15 m/min, said water cooling system runs the risk of forming vapor films at the ‘cold face’ of the mold shell (
20
), because the vapor point at a preset pressure is exceeded the over-temperature in the thermal transfer region of the copper wall.
The heat exchanger (
18
) is cooled via a cooling tower (
21
) equipped with a pump station (
21
.
1
).
The object of the invention is to create a generic process and device which improve upon the mold operation and the continuous casting process.
SUMMARY OF THE INVENTION
The unanticipated solution that is not obvious to one skilled in the art is made clear by the characteristics. Pursuant to the invention, a mold cooling system is achieved in which the mold skin temperature ‘hot face’ (
14
) remains constant under varying casting conditions and is maintained under control whereby constant conditions are established for the casting powder (
3
) and the casting slag (
3
.
1
) wherein an unperturbed thermal flux (
17
) is assured over the width of the casting without the formation of a vapor layer (Leidenfrost effect).
REFERENCES:
patent: 3783937 (1974-01-01), Maurer
patent: 6179041 (2001-01-01), Pleschiutschnigg
patent: 6299071 (2001-10-01), Fiedrich
Feldhaus Stephan
Friedrich Jürgen
Kopfstedt Uwe
Parschat Lothar
Pleschiutschnigg Fritz-Peter
Lin I.-H.
Sidley Austin Brown & Wood LLP
SMS Demag Aktiengesellschaft
LandOfFree
Method and device for thermal control of a continuous... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and device for thermal control of a continuous..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and device for thermal control of a continuous... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3094869