U.S. patent application number 16/093209 was filed with the patent office on 2019-07-04 for instrumentation of a side wall of a continuous casting mold with optical waveguides.
The applicant listed for this patent is Primetals Technologies Austria GmbH. Invention is credited to Oliver LANG, Guenter LEITNER, Stefan LEITNER, Christian ORTNER, Martin SCHUSTER.
Application Number | 20190201971 16/093209 |
Document ID | / |
Family ID | 58609435 |
Filed Date | 2019-07-04 |
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United States Patent
Application |
20190201971 |
Kind Code |
A1 |
LANG; Oliver ; et
al. |
July 4, 2019 |
INSTRUMENTATION OF A SIDE WALL OF A CONTINUOUS CASTING MOLD WITH
OPTICAL WAVEGUIDES
Abstract
First, an auxiliary cut-out (11, 16) is formed in a side wall
(1) of a continuous casting mold. That cut-out extends, in the
longitudinal direction, at least over the cut-out length (L) of the
useful cut-out (10) and has an auxiliary cross-section orthogonal
to the longitudinal direction. Then, an additional element (13, 14,
17) is inserted into the auxiliary cut-out (11, 16), and extends,
in the longitudinal direction, at least over a cut-out length (L)
of a later useful cut-out (10) and bounds the useful cut-out (10)
orthogonally to the longitudinal direction at least over part of
the periphery of the useful cut-out. The useful cut-out (10) is
formed by inserting the additional element (13, 14, 17) into the
auxiliary cut-out (11, 16). The useful cut-out (10) is closed all
around orthogonally to the longitudinal direction. Orthogonally to
the longitudinal direction, the useful cut-out has a
(correspondingly small) useful cross-section and a maximum useful
extent (d3). The useful cross-section is defined in such a way that
an optical waveguide (9) can be reversibly inserted into the useful
cut-out. The production method makes it possible that a ratio of
the cut-out length (L) to the maximum useful extent (d3) is 100:1
or greater.
Inventors: |
LANG; Oliver; (Dietach,
AT) ; LEITNER; Guenter; (Freistadt, AT) ;
LEITNER; Stefan; (Kollerschlag, AT) ; ORTNER;
Christian; (Wilhering, AT) ; SCHUSTER; Martin;
(Kopfing, AT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Primetals Technologies Austria GmbH |
Linz |
|
AT |
|
|
Family ID: |
58609435 |
Appl. No.: |
16/093209 |
Filed: |
April 25, 2017 |
PCT Filed: |
April 25, 2017 |
PCT NO: |
PCT/EP2017/059766 |
371 Date: |
October 12, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B22D 11/202 20130101;
B22D 11/16 20130101; B22D 2/006 20130101 |
International
Class: |
B22D 11/20 20060101
B22D011/20; B22D 2/00 20060101 B22D002/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 27, 2016 |
AT |
A50373/2016 |
Claims
1. A method for introducing a useful cut-out into a side wall of a
continuous casting mold, wherein the useful cut-out extends over a
cut-out length in a longitudinal direction of the useful cut-out,
is closed all around orthogonally to the longitudinal direction and
has orthogonally to the longitudinal direction a useful cross
section and a maximum useful extent, wherein the useful cross
section is determined so that an optical waveguide is reversibly
insertable into and removable from the useful cut-out; first
introducing an auxiliary cut-out into the side wall, wherein the
auxiliary cut-out extends at least over the cut-out length of the
useful cut-out in the longitudinal direction and the auxiliary
cut-out has orthogonally to the longitudinal direction an auxiliary
cross section that is greater than the useful cross section;
inserting an additional element into the auxiliary cut-out, the
additional element is formed as a rod with at least one groove
arranged on its outer side or is formed as a tube and the rod or
the tube extends at least over the cut-out length of the useful
cut-out in the longitudinal direction, wherein inserting the
additional element into the auxiliary cut-out, forms the useful
cut-out; and wherein, seen orthogonally to the longitudinal
direction, the surfaces of the rod that bound the groove also bound
the useful cut-out over part of its circumference and the side wall
bounds the useful cut-out over the remaining part of its
circumference or the inner side of the tube bounds the useful
cut-out over its entire circumference.
2. The method as claimed in claim 1, wherein the sidewall has a
cold side and a warm side; the method comprising: forming the
auxiliary cut-out as a groove that is open toward the cold side of
the side wall, only partially filling the auxiliary cut-out toward
the cold side with the additional element so that part of the
auxiliary cut-out remains toward the cold side, and as seen from
the additional element, filling the auxiliary cut-out from the cold
side with a filling material.
3. The method as claimed in claim 1, further comprising: forming
the auxiliary cut-out as a closed cut-out, seen orthogonally to the
longitudinal extent.
4. The method as claimed in claim 3, further comprising the
additional element substantially filling the auxiliary cut-out with
the additional element.
5. The method as claimed in claim 1, wherein the additional element
consists of the same material as the side wall.
6. The method as claimed in claim 1, wherein a ratio of the cut-out
length to a maximum useful extent of a useful cut-out is at least
100:1.
7. A side wall of a continuous casting mold, comprising: a useful
cut-out in the side wall, the useful cut-out extending over a
cut-out length in a longitudinal direction of the useful cut-out,
the useful cut-out is closed all around orthogonally to the
longitudinal direction and has a useful cross section and a maximum
useful extent; wherein the useful cross section is determined such
that an optical waveguide is reversibly insertable into the useful
cut-out; an additional element is arranged in the side wall, the
additional element being formed as a rod with at least one groove
arranged on an outer side of the additional element or as a tube
that extends at least over the cut-out length of the useful cut-out
in the longitudinal direction; seen orthogonally to the
longitudinal direction, surfaces of the rod that bound the groove
also bound the useful cut-out over part of a circumference thereof,
and the side wall bounds the useful cut-out over the remaining part
of the circumference thereof or the inner side of the tube bounds
the useful cut-out over the entire circumference thereof; and
wherein the additional element is completely surrounded by material
toward the cold side of the side wall.
8. The side wall as claimed in claim 7, further comprising the
additional element is coated toward the cold side with a coating
material.
9. The side wall as claimed in claim 7, further comprising: the
side wall has an auxiliary cut-out extending at least over the
cut-out length of the useful cut-out in the longitudinal direction,
the auxiliary cut-out is formed as a closed cut-out, seen
orthogonally to the longitudinal extent, and has orthogonally to
the longitudinal direction an auxiliary cross section that is
greater than the useful cross section, and in that the additional
element is inserted into the auxiliary cut-out.
10. The side wall as claimed in claim 9, wherein the auxiliary
cut-out is formed as a bore.
11. The side wall as claimed in claim 9, wherein the additional
element substantially fills the auxiliary cut-out.
12. The side wall as claimed in claim 7, wherein the additional
element consists of the same material as the side wall.
13. The side wall as claimed in claim 7, wherein a ratio of the
cut-out length to the maximum useful extent is at least 100:1.
14.-18. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a 35 U.S.C. .sctn..sctn. 371
national phase conversion of PCT/EP2017/059766, filed Apr. 25,
2017, which claims priority of Austrian Patent Application No.
A50373/2016, filed Apr. 27, 2016, the contents of which are
incorporated by reference herein. The PCT International Application
was published in the German language.
TECHNICAL BACKGROUND
[0002] The present invention is based on a method for introducing a
useful cut-out into a side wall of a continuous casting mold. The
useful cut-out extends over a cut-out length in a longitudinal
direction of the useful cut-out, is closed all around orthogonally
to the longitudinal direction and has orthogonally to the
longitudinal direction a useful cross section and a maximum useful
extent, wherein the useful cross section is determined in such a
way that an optical waveguide is reversibly insertable into the
useful cut-out.
[0003] The present invention is also based on a side wall of a
continuous casting mold, [0004] wherein a useful cut-out is
introduced into the side wall, which useful cut-out extends over a
cut-out length in a longitudinal direction of the useful cut-out,
is closed all around orthogonally to the longitudinal direction and
has orthogonally to the longitudinal direction a useful cross
section and a maximum useful extent, [0005] wherein the useful
cross section is determined in such a way that an optical waveguide
is reversibly insertable into the useful cut-out.
[0006] During continuous casting, liquid metal is continuously
poured into a mold and solidifies on side walls of the mold to form
a metal strand comprising an already solidified strand shell and a
still liquid core. Synchronously with the pouring of the liquid
metal into the mold, the metal strand is drawn off out of the mold.
The drawing off of the metal strand is coordinated with the pouring
in such a way that a casting level, that is the level of the liquid
in the mold, remains substantially constant.
[0007] At the point in time at which the metal strand leaves the
mold, the strand shell must already be sufficiently thick.
Otherwise, there is the risk of a shell rupture. Decisive for a
stable casting process are in particular orderly cooling and a
casting rate adapted to the mold. Furthermore, the strand shell
must not stick to the mold walls. In particular, such sticking or
catching of the shell must be detected in time, since otherwise a
shell rupture occurs.
[0008] To detect such sticking, it is known to measure the
temperature distribution in the mold by corresponding sensors.
Generally, this involves the sensors being arranged in a
two-dimensionally distributed manner. The corresponding arrangement
of the sensors and their evaluation are known to those skilled in
the art.
[0009] Thermocouples may be disturbed by electromagnetic fields.
Such disturbing electromagnetic fields may be caused for example by
electromagnetic stirrers (MEMS=mold electromagnetic stirrer) or
electromagnetic brakes (EBM=electromagnetic brake). Since the use
of such electromagnetic stirrers and electromagnetic brakes is
increasing, there is an increasing problem of disturbances.
[0010] In order to reduce the electromagnetic disturbances in the
case of thermocouples, it is known to twist and shield the lines.
Furthermore, filters are often additionally installed, in order to
reduce disturbing frequencies. However, both measures generally
have a negative influence on the capability of detecting catching
of the shell. Furthermore, the installation of many measuring
points with thermocouples also quickly encounters structural design
limits.
[0011] It is also known in the prior art to detect a temperature
value by means of suitable optical waveguides, in particular by
means of optical waveguides that are based on the fiber Bragg
effect. It is also already known to use such optical waveguides in
the case of continuous casting molds.
[0012] For example, reference is made to EP 2 440 883 B1. EP 2 318
162 B1 and JP 2008 043 981 A may also be mentioned in this
connection.
[0013] In EP 2 440 883 B1, the optical waveguide is placed onto the
side wall of the continuous casting mold. Then a coating is applied
to that side of the side wall onto which the optical waveguide has
been placed. The coating fixes the optical waveguide. After the
fixing, the optical waveguide is undetachably connected to the side
wall.
[0014] In EP 2 318 162 B1, the optical waveguide is applied to a
probe. The probe is inserted into a groove, a bore or a similar
opening and can also be removed from it again. In EP 2 318 162 B1,
the optical waveguide is used for the purpose of detecting the
height of the casting level. Only a relatively small extent of the
optical waveguide in the vertical direction is required for this
purpose.
[0015] In JP 2008 043 981 A1, an optical waveguide is surrounded by
a metal tube and is secured, including the metal tube, in the side
wall of a continuous casting mold.
[0016] WO 2015/058 911 A1 discloses in a first exemplary embodiment
introducing a groove into a side wall of a continuous casting mold,
placing a first foil onto the groove base, placing a cannula with
an optical waveguide onto the first foil, then placing a second
foil onto the first foil and the optical waveguide and finally
covering or closing the groove with a filler. WO 2015/058 911 A1
also discloses in a second exemplary embodiment introducing into a
side wall of a continuous casting mold a bore of a diameter that is
slightly greater than the diameter of a cannula containing an
optical waveguide and inserting the cannula with the optical
waveguide into the bore. WO 2015/058 911 A1 also discloses a third
exemplary embodiment introducing into a side wall of a continuous
casting mold a bore of a diameter that is considerably greater than
the diameter of a cannula containing an optical waveguide and
inserting the cannula with the optical waveguide into the bore.
[0017] WO 2011/098 309 A1 discloses introducing into a side wall of
a continuous casting mold grooves into which optical waveguides are
placed. The grooves are then closed again. The optical waveguides
are fixed by hold-down devices.
[0018] DE 10 2010 008 480 A1 discloses introducing into a side wall
of a continuous casting mold a groove into which an optical
waveguide is placed. The groove is then closed again. The optical
waveguide is fixed in the groove.
[0019] WO 03/035 306 A1 discloses introducing into a side wall of a
continuous casting mold coolant channels into which displacement
rods are then inserted to reduce the cross section.
[0020] JP 2008 260 046 A discloses introducing a bore into the side
wall of a mold. An optical waveguide provided with a protective
casing is inserted into the bore. A guiding wire may be
additionally fixed on the protective casing, and the wire can be
inserted together with the optical waveguide into the bore.
SUMMARY OF THE INVENTION
[0021] The object of the present invention is to create
possibilities for allowing an optical waveguide to be reversibly
inserted into the side wall in an easy way. It is intended that the
optical waveguide should in this case be able to extend over a
great length, in particular seen in the longitudinal direction of
the useful cut-out.
[0022] The object is achieved by a method disclosed herein.
[0023] According to the invention, for introducing the useful
cut-out, it is provided [0024] that first an auxiliary cut-out is
introduced into the side wall, which auxiliary cut-out extends at
least over the cut-out length of the useful cut-out in the
longitudinal direction and has orthogonally to the longitudinal
direction an auxiliary cross section that is greater than the
useful cross section, [0025] that an additional element is inserted
into the auxiliary cut-out; the additional element is formed as a
rod with at least one groove arranged on its outer side or as a
tube and extends at least over the cut-out length of the useful
cut-out in the longitudinal direction, [0026] that by inserting the
additional element into the auxiliary cut-out, the useful cut-out
is formed and [0027] that seen orthogonally to the longitudinal
direction, the surfaces of the rod that bound the groove also bound
the useful cut-out over part of its circumference and the side wall
bounds the useful cut-out over the remaining part of its
circumference or the inner side of the tube bounds the useful
cut-out over its entire circumference.
[0028] The additional element remains permanently in the side wall.
It is connected directly to the side wall. The additional element
may alternatively be arranged irreversibly, that is fixedly and
non-removably, or reversibly in the side wall. However, in both
cases the useful cut-out formed by the additional element
represents a remaining cavity into which the optical waveguide can
later be reversibly inserted. By this procedure it is possible to
create a useful cut-out with a small useful cross section (for
example a diameter of about 1.5 to 3.0 mm, in particular of 1.8 to
2.5 mm), the cut-out length extends over the entire, or virtually
the entire, height or width of the side wall.
[0029] For example, the auxiliary cut-out may be formed as a groove
that is open toward the cold side of the side wall. In this case,
the additional element only partially fills the auxiliary cut-out
toward the cold side. The part of the auxiliary cut-out remaining
toward the cold side, as seen from the additional element, is in
this case filled from the cold side with a filling material. The
filling material preferably coincides with the material of the side
wall toward the hot side. Therefore, if the side wall consists for
example of copper (as is regularly the case in particular when
continuously casting steel), the filling material is preferably
also copper. The same applies in the case a filling of another
material. As a result of the filling material, the additional
element is completely surrounded on the cold side by the coating
material. The cold side is that side of the side wall that is
facing away from the liquid metal during the operation of the
continuous casting mold. Conversely, the hot side is that side of
the side wall that is adjacent to the liquid metal during the
operation of the continuous casting mold.
[0030] As an alternative to the auxiliary cut-out being formed as a
groove that is open toward the cold side of the side wall, the
auxiliary cut-out may be formed as a closed cut-out, seen
orthogonally to the longitudinal extent. In particular, the cut-out
may be a bore. The bore may for example have a diameter that is as
a minimum 6 mm, preferably at least 8 mm, in particular at least 10
mm. As a maximum, the diameter may be up to 20 mm, preferably not
exceeding a value of 15 mm, in particular of 12 mm.
[0031] For a closed cut-out, it is for example possible that the
additional element substantially fills the auxiliary cut-out.
[0032] The additional element preferably consists of the same
material as the side wall. As a result, on the one hand, a uniform
coefficient of thermal conduction is obtained, and on the other
hand, a uniform coefficient of expansion of the side wall and the
additional element is obtained.
[0033] The maximum useful extent is equal to the diameter of a
circle circumscribing the useful cross section, that is to say the
circle with the smallest diameter that, on the one hand, completely
surrounds the useful cross section, and on the other hand, touches
the useful cross section, but does not intersect it. In an
analogous way, a minimum useful extent is equal to the diameter of
a circle inscribed in the useful cross section, that is the circle
with the greatest diameter that is completely surrounded by the
useful cross section and touches the useful cross section but does
not intersect it. The maximum useful extent has for example a value
of typically 1.5 mm to 4 mm. The minimum useful extent typically
has a value of 1.5 mm to 3 mm. Depending on the type of useful
cross section, the minimum useful extent typically lies in the
range between 57% and 100% of the maximum useful extent. In a
circular useful cross section, the ratio is, for example, 100%. In
a square useful cross section, the ratio is, for example, about
71%. By contrast, the cut-out length is considerably greater than
the maximum useful extent. It may, for example, be 500 to 800 mm.
In particular, it is possible that a ratio of the cut-out length to
the maximum useful extent is at least 100:1. Still greater ratios
are also possible, for example at least 120:1, at least 150:1, at
least 200:1, at least 300:1, at least 400:1 and of at least 500:1.
The reason why such a great ratio is achievable is that, because of
the manner in which the useful cut-out is produced, the achievable
cut-out length is not limited at all in the case of an auxiliary
cut-out formed as an open groove, is limited by the transverse
extent of the auxiliary cut-out, but not by the transverse extent
of the useful cut-out in the case of an auxiliary cut-out formed as
a closed cut-out.
[0034] The object is also achieved by a side wall with the features
disclosed herein.
[0035] According to the invention, a side wall of the type
mentioned at the beginning is developed [0036] in that an
additional element is arranged in the side wall, which additional
element is formed as a rod with at least one groove arranged on its
outer side or is formed as a tube and extends at least over the
cut-out length of the useful cut-out in the longitudinal direction,
[0037] in that, seen orthogonally to the longitudinal direction,
the surfaces of the rod that bound the groove bound the useful
cut-out over part of its circumference and the side wall bounds the
useful cut-out over the remaining part of its circumference or the
inner side of the tube bounds the useful cut-out over its entire
circumference and [0038] in that the additional element is
completely surrounded by material toward the cold side of the side
wall.
[0039] The additional element remains permanently in the side wall.
It is connected directly to the side wall. The additional element
may alternatively be arranged irreversibly, that is fixedly and
non-removably, or reversibly in the side wall. However, in both
cases the useful cut-out formed by the additional element
represents a remaining cavity into which the optical waveguide can
later be reversibly inserted. As a result, the useful cut-out may,
as already mentioned, in particular have a small useful cross
section, which may for example correspond to a diameter of about
1.5 mm to 3.0 mm, in particular of 1.8 mm to 2.5 mm, while the
cut-out length may extend over the entire height or width of the
side wall.
[0040] The advantageous developments of the side wall correspond
substantially to those of the method.
[0041] For instance, it is possible in particular that the
additional element is coated with a coating material toward the
cold side, the filling material preferably coinciding with the
material of the side wall toward the hot side.
[0042] It is also possible that the side wall has an auxiliary
cut-out, which extends at least over the cut-out length of the
useful cut-out in the longitudinal direction, is formed as a closed
cut-out, seen orthogonally to the longitudinal extent, and has
orthogonally to the longitudinal direction an auxiliary cross
section that is greater than the useful cross section, and that the
additional element is inserted into the auxiliary cut-out. The
auxiliary cut-out may in this case be formed in particular as a
bore.
[0043] The additional element may substantially fill the auxiliary
cut-out.
[0044] The additional element preferably consists of the same
material as the side wall.
[0045] As before, it is possible that the useful cut-out has a
maximum useful extent, seen orthogonally to the longitudinal
direction, and a ratio of the cut-out length to the maximum useful
extent is at least 100:1. Here, too, greater ratios are possible,
for example at least 120:1, at least 150:1, at least 200:1, at
least 300:1, of at least 400:1 and of at least 500:1.
[0046] The properties, features and advantages of this invention
described above and the manner in which they are achieved will be
more clearly and distinctly comprehensible in conjunction with the
following description of the exemplary embodiments, which are
explained in greater detail in conjunction with the schematically
represented drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] FIG. 1 shows part of a continuous casting mold from the
side,
[0048] FIG. 2 shows a continuous casting mold from above,
[0049] FIG. 3 shows an enlarged representation of a detail from
FIG. 1,
[0050] FIG. 4 shows a side wall with a groove,
[0051] FIG. 5 shows the side wall from FIG. 4 with a tube placed
into the groove,
[0052] FIG. 6 shows the side wall from FIG. 4 with a covering
placed into the groove,
[0053] FIG. 7 shows a tube,
[0054] FIG. 8 shows the side wall from FIG. 5 in the finished
state,
[0055] FIG. 9 shows the side wall from FIG. 6 in the finished
state,
[0056] FIG. 10 shows a side wall with a bore and
[0057] FIG. 11 shows the side wall from FIG. 10 in the finished
state.
DESCRIPTION OF EMBODIMENTS
[0058] Side walls 1 of a continuous casting mold are used, in a way
corresponding to the representation in FIGS. 1 and 2, to bound a
liquid metal 2, for example steel or aluminum, while the metal 2 is
solidifying on hot sides 3 of the side walls 1 to form a strand
shell 4 with a still liquid core 5. The metal strand 6, consisting
of the strand shell 4 and the liquid core 5, is drawn off out of
the continuous casting mold in a drawing-off direction x. The
continuous casting mold may in a way corresponding to the
representation in FIGS. 1 and 2, have a number of plates, which
together form a rectangular cavity for receiving the liquid metal
2. Alternatively, the continuous casting mold may be formed as an
individual, closed side wall 1 completely surrounding the cavity.
In many cases, adjusting devices 8, which can set the size of the
cavity, are arranged on cold sides 7.
[0059] Further elements of the continuous casting mold are in
particular cooling devices, by means of which the side walls 1 are
cooled. The cooling devices are not shown in the figures for
reasons of overall clarity.
[0060] A height H of the side walls 1 often lies in the range of 50
cm to 2 m. A width B may lie in the range between 20 cm and 3 m. A
thickness D usually lies in the range of a few cm, for example 20
mm to 60 mm.
[0061] For the thermal monitoring of the continuous casting mold,
optical waveguides 9 are arranged in the side walls 1, as seen in
the detail of FIG. 3. The corresponding use of optical waveguides 9
is generally known to those skilled in the art. It is based on the
fiber Bragg effect. The optical waveguides 9 may alternatively run
horizontally or vertically in the side walls 1. In FIGS. 1 and 2, a
horizontally running optical waveguide 9 and a vertically running
optical waveguide 9 are respectively shown. There are generally a
number of optical waveguides 9, which may for example all run
vertically or all run horizontally. However, mixed vertical and
horizontal direction or oblique direction forms are also possible.
Thus, for reasons of easier assembly and greater operational
reliability, it is for example of advantage to insert the optical
waveguides 9 horizontally into the side wall 1. Most of the optical
waveguides 9 in this case run only horizontally within the side
wall 1.
[0062] In order, for example, to be able to detect the height of a
casting level exactly, there may be a single further optical
waveguide 9, referred to hereinafter as the additional optical
waveguide 9. Seen in the direction of the height, the additional
optical waveguide 9 must overcome a certain difference in height.
This may be achieved on the one hand by the additional optical
waveguide 9 running vertically. In this case, the additional
optical waveguide 9 is inserted into the side wall 1 from above or
from below. Preferably, however, the additional optical waveguide 9
is also inserted laterally into the side wall 1, but runs within
the side wall 1 at an angle to the horizontal. The angle is
different from 90.degree.. It may for example lie between
10.degree. and 45.degree.. The additional optical waveguide 9 in
this case extends over a length such that, with allowance for the
angle that it forms with the horizontal, it overcomes the desired
difference in height. The difference in height may, for example, be
between 80 mm and 150 mm, in particular between 90 mm and 120 mm,
for example about 100 mm.
[0063] Customary suitable optical waveguides 9 often have a
diameter d1 (FIG. 3), which lies in the range well below 1 mm, for
example about 150 .mu.m to 250 .mu.m. The optical waveguides 9 may
be surrounded by a protective casing 9'. The protective casing 9'
is often also referred to as a cannula. The protective casing 9'
often consists of metal, for example high-grade steel. Including
the protective casing 9', the optical waveguides 9 often have a
diameter d2, which lies in the range of somewhat over 1 mm, for
example 1.2 mm to 2.0 mm.
[0064] For receiving the optical waveguides 9, useful cut-outs 10
have been introduced into the side wall 1. The useful cut-outs 10
extend over a respective cut-out length L in a longitudinal
direction of the respective useful cut-out 10. The cut-out length L
may coincide with the height H or the width B of the respective
side wall 1. In this case, it is a continuous, useful cut-out 10,
which is open to both sides. Alternatively, the cut-out length L
may be shorter. In this case, the useful cut-out 10 ends in the
side wall 1 in a way similar to a blind bore. Orthogonally to the
longitudinal direction, the useful cut-outs 10 are closed all
around. They have orthogonally to the longitudinal direction a
cross section and a maximum extent. The cross section and the
maximum transverse extent of the useful cut-outs 10 are referred to
hereinafter as the useful cross section and the maximum useful
extent. This choice of words only serves for verbal differentiation
from other cross sections and extents.
[0065] Because the useful cut-outs 10 are intended for receiving
the optical waveguides 9, the useful cross section is determined in
such a way that one optical waveguide 9 can be respectively
inserted into the useful cut-out 10. The optical waveguides 9 may
alternatively be inserted into useful cut-outs 10 with the
protective casings 9' or without the protective casings 9'. The
minimum useful extent must be slightly greater than the diameter of
the optical waveguides 9 with or without the protective casings 9'.
Accordingly, the minimum useful extent should be above 1.2 mm to
2.0 mm, for example 1.5 mm to 3.0 mm, depending on the optical
waveguide that is used. Depending on the form of the useful cross
section, the maximum useful extent either has the same value or is
slightly greater. In particular, it may lie between 1.5 mm and 4.0
mm. The maximum useful extent should only assume values above 3 mm
when this is required to achieve a sufficiently great minimum
useful extent.
[0066] The possibility of inserting the optical waveguides 9 into
the useful cut-outs 10 is reversible. The optical waveguides 9 can
therefore also be removed again from the useful cut-outs 10.
Therefore, for a circular useful cross section, the useful cut-outs
10 may, for example, have a diameter d3, which lies in the range
between 1.5 mm and 3.0 mm, in particular between 2.0 mm and 2.5 mm.
For a circular useful cross section, the diameter d3 corresponds
both to the minimum useful extent and to the maximum useful extent.
In the case of a square useful cross section, the indicated
numerical values may apply for example to the side length of the
square shape useful cross section. In the case of a square useful
cross section, the maximum useful extent is determined by the
diagonal of the square. For the maximum useful cross section, the
numerical values are therefore to be provided with a factor of
somewhat over 1.4. It is assumed hereinafter that the useful cross
section is circular. However, similar circumstances also apply in
the case of some other useful cross section.
[0067] As already mentioned, the height H of the side walls 1 often
lies in the range from 50 cm to 2 m, and the width B lies in the
range between 20 cm and 3 m. As likewise already mentioned, it is
possible that the cut-out length L coincides with the height H or
the width B of the respective side wall 1. A ratio of the cut-out
length L to the maximum useful extent for example the quotient
L/d3) can therefore become very large. Although it is possible that
the ratio only assumes relatively small values, for example 50 or
80. It is however similarly possible that greater values are
assumed, for example 100:1 or more, 120:1 or more, 150:1 or more,
and so on. How this can be achieved is explained in more detail
below in conjunction with the further FIGS. 4-6.
[0068] For producing at least one useful cut-out 10, first an
auxiliary cut-out 11 is introduced into the side wall 1. For
example, corresponding to the representation in FIG. 4, a groove 11
may be introduced into the side wall 1 as the auxiliary cut-out 11.
The introduction of the groove 11 takes place in this case from the
cold side 7 of the side wall 1. The groove 11 is therefore open
toward the cold side 7 of the side wall. The groove 11 may for
example be formed in a semicircular or V-shaped manner in
cross-section. Other forms are also possible. The groove 11 may for
example be introduced into the side wall by simple milling or the
like. A groove depth t is dimensioned such that the groove base 12
(i.e. the deepest point of the groove 11) is at a predetermined
distance a from the hot side 3 of the side wall 1. The auxiliary
cut-out 11 extends at least over the cut-out length L of the useful
cut-out 10 in the longitudinal direction of the (later) useful
cut-out 10. Orthogonally to the longitudinal direction, the
auxiliary cut-out 11 has a cross section. The cross section of the
auxiliary cut-out 11 is greater than the useful cross section. It
is referred to hereinafter as the auxiliary cross section. This
choice of words only serves however for verbal differentiation from
other cross sections.
[0069] Then, in a way corresponding to the representation in FIGS.
5 and 6, an additional element 13 or 14 is inserted into the
auxiliary cut-out 11. The additional element 13, 14 preferably
consists of the same material as the side wall 1. If, therefore,
the side wall 1 consists of copper, for example, the additional
element 13, 14 also consists of copper. Alternatively, the
additional element 13, 14 may consist of a material that has
similar properties to the material of the side wall 1. This applies
in particular to the coefficient of thermal expansion and
preferably also to the thermal conductivity.
[0070] The additional element 13 or 14 likewise extends at least
over the cut-out length L of the useful cut-out 10 in the
longitudinal direction. For example, in a way corresponding to the
representation in FIG. 5, the additional element 13 may be formed
as a tube 13, the inward side of which bounds the useful cut-out
10. Seen orthogonally to the longitudinal direction, in this case
the useful cut-out 10 is completely surrounded or bounded by the
additional element 13.
[0071] Alternatively, the additional element 14 may be formed in a
way corresponding to the representation in FIG. 6 as a covering 14.
In this case, the covering 14 covers the groove base 12. The region
between the covering 14 and the groove base 12 corresponds in this
case to the useful cut-out 10. Consequently, seen from the useful
cut-out 10, the covering 14 is arranged on the cold side 7 of the
side wall 1. Seen orthogonally to the longitudinal direction, it
partially, but not completely, bounds the useful cut-out 10. In
both cases, consequently, the useful cut-out 10 is formed by the
insertion of the additional element 13, 14 into the auxiliary
cut-out 11.
[0072] The additional element 13 which is developed as a tube 13
may, in a way corresponding to the representation in FIG. 7,
consist of a number of portions 13', which are placed one after the
other, seen in the longitudinal direction of the useful cut-out 10.
The portions 13' may in this case have guiding surfaces 13'' that
interact with one another, so that the useful cut-out 10 passes
through continuously. Also for example, corresponding to the
representation in FIG. 7, the useful cut-out 10 may be slightly
widened in the end regions of the portions 13', in order to
facilitate the leading in and leading through of the optical
waveguide 9 through all of the portions 13'.
[0073] The additional element 13 or 14 only partially fills the
auxiliary cut-out 11 or groove 11 toward the cold side 7 of the
side wall 1. Depending on the form of the groove 11 and depending
on the development of the additional element 13 or 14, the degree
of filling may be at greater or smaller values. For example, the
degree of filling may lie between 30% and 10%. Sometimes, the
degree of filling is even less. In FIGS. 8 and 9, after the
insertion of the additional element 13 or 14, the part of the
auxiliary cut-out 11 remaining toward the cold side 7 of the side
wall 1 is filled from the cold side 7 of the side wall 1 with a
filling material 15. This completely surrounds the additional
element 13 or 14 by the filling material 15 on the cold side 7 of
the side wall 1. In particular, the filling material 15 is
cohesively connected to the side wall 1 and the additional element
13 or 14. As a result, the additional element 13, 14 is arranged
irreversibly, that is fixedly, permanently and non-removably, in
the side wall 1 or in the auxiliary cut-out 11. As a result, the
additional element 13 or 14 is connected directly to the side wall
1 without an intermediate space. The additional element 13 or 14
defines a cavity, that is a space, that is not filled with
material, into which the optical waveguide 9 can later be
reversibly inserted and which cavity is the useful cut-out 10.
[0074] In the ideal case, the filling material 15 coincides with
the material of the side wall 1 toward the hot side 3. If the side
wall 1 consists, for example, of copper, the filling material is
also ideally consists of copper. This also applies whenever the
side wall 1 has on the hot side 3 an additional coating 3', for
example of nickel, chromium or ceramic. Also in this case, the
material of the side wall 1 means the "actual" material of the side
wall 1, not the material of the coating 3'. FIGS. 8 and 9 show the
corresponding side walls. The filling material 15 is in this case
preferably applied by coating to the cold side 7 of the side wall
1. Alternatively, some other material may be used as filling
material 15. This applies in particular whenever the groove 11 is
relatively narrow. In such cases, nickel, chromium, brass or a
synthetic resin may be used for example as the filling material 15.
Depending on the situation of the individual case, application by
coating may also be possible in this case.
[0075] Any coating applied on the cold side 7 may for example be
applied to a thermal spraying process or to a galvanic process.
Corresponding processes are generally known to those skilled in the
art. For example, as thermal processes there are wire-flame
spraying, plasma spraying, powder-vapor spraying, high-velocity
flame spraying and cold-gas spraying. What is important for an
applied 7 coating is that the filling material 15 be applied as
one. If the filling material 15 coincides with the material of the
side wall 1 toward the hot side 3, a uniform side wall 1 is formed
during the coating, in which a transition from the original side
wall 1 to the filling material 15 is not detectable, or is scarcely
detectable. Also, the resultant thermal conductivity of the side
wall 1, except for the useful cut-out 10, is unchanged with respect
to the thermal conductivity of the side wall 1, as it was before
the introduction of the groove 11.
[0076] As mentioned above, the groove 11 may be for example be
V-shaped or semicircular. Irrespective of the specific form of the
groove 11 and corresponding to the representations in FIGS. 5 and
6, a further groove 12' has been introduced into the groove base 12
itself. In the development according to FIG. 5, the additional
element 13 is formed as a tube 13, and the further groove 12' may
in particular be formed to match the outside diameter of the tube
13. In the development according to FIG. 6, the additional element
14 is formed as a covering 14, and the further groove 12' is
preferably determined by the size of the later useful cut-out 10.
In particular, in this case, corresponding to the representation in
FIG. 5, the covering 14 may be formed as a simple sheet-like
covering, which covers the further groove 12'.
[0077] A further possibility for introducing the useful cut-out 10
into the side wall 1 is explained below in conjunction with FIGS.
10 and 11. According to FIGS. 10 and 11, an auxiliary cut-out 16 is
introduced into the side wall 1. In FIG. 10, as also in FIGS. 4 to
9, the auxiliary cut-out 16 extends at least over the cut-out
length L of the useful cut-out 10 in the longitudinal direction.
Also, as in FIGS. 4 to 9, the auxiliary cut-out 16 has,
orthogonally to the longitudinal direction, an auxiliary cross
section that is greater than the useful cross section. However, in
contrast to the development of FIGS. 4 to 9, the auxiliary cut-out
16 of FIGS. 10 and 11 is formed as a closed cut-out, seen
orthogonally to the longitudinal extent. For example, the auxiliary
cut-out 16 may be a bore with a correspondingly large diameter d4.
The diameter d4 may for example lie between 6 mm and 20 mm, and in
particular between 8 mm and 15 mm.
[0078] Then, an additional element 17 is inserted into the
auxiliary cut-out 16. FIG. 11 shows the corresponding state. The
additional element 17 preferably consists of the same material as
the side wall 1. The statements made above in relation to the
additional elements 13, 14 may be applied in an analogous way.
[0079] The additional element 17 extends at least over the cut-out
length L of the useful cut-out 10 in the longitudinal direction. It
is preferably formed, corresponding to the representation in FIG.
11, as a rod 17, which substantially fills the auxiliary cut-out
16, but has on its outer side at least one groove 18 extending in
the longitudinal direction of the useful cut-out 10. Seen
orthogonally to the longitudinal direction, the additional element
17 (or the surfaces of the additional element 17 that bound the
groove 18) only bound(s) the useful cut-out 10 over part of its
circumference. Over the remaining part of its circumference, the
useful cut-out 10 is in this case bounded by the side wall 1.
Alternatively, analogous to the development of the tube 13, here,
too, the additional element 17 could be formed as a tube in
particular, as a multipiece tube. Also in the case of the
development of FIGS. 10 and 11, however, the useful cut-out 10 is
formed by the insertion of the additional element 17 into the
auxiliary cut-out 16.
[0080] When the auxiliary cut-out 16 is closed all around, in
particular as a bore, the practically achievable length is limited
by the diameter d4. In practice, generally, the depth of an
achievable bore can at most be about 100 times the diameter of the
bore. This is also applied in the context of the present invention.
With a diameter d4 of, for example, 10 mm, a maximum bore depth of
about 1000 mm is therefore achievable, with a diameter d4 of, for
example 12 mm, a maximum bore depth of about 1200 mm is achievable.
With a smaller or greater diameter d4, the achievable bore depth is
correspondingly smaller or greater. The achievable bore depth, and
consequently the cut-out length L, is limited by the diameter d4 of
the auxiliary cut-out 16, but not by the diameter d3 or a dimension
equivalent thereto of the useful cut-out 10. It is therefore
possible to achieve a great cut-out length L of the useful cut-out
10, although the maximum useful extent of the useful cut-out 10 is
small.
[0081] In the minimum case, it is adequate if the additional
element has a single groove 18. Alternatively, the additional
element 17 may have a plurality of such grooves 18. Various
advantageous effects can be realized depending on the number and
arrangement of the grooves 18 along the circumference of the
additional element 17 and depending on the orientation of the
additional element 17 in the auxiliary cut-out 16. For example,
corresponding to FIG. 11, there may be two grooves 18 offset by
180.degree. with respect to one another along the circumference. If
the additional element 17 is oriented in the auxiliary cut-out 16
such that the two grooves 18 define a plane that runs parallel to
the hot side 3 of the side wall 1, a redundancy and/or a spatial
resolution can be achieved in the temperature detection. If, on the
other hand, the additional element 17 is oriented in the auxiliary
cut-out 18 such that the two grooves 18 define a plane that is
oriented orthogonally to the hot side 3 of the side wall 1, the
temperature gradient can be determined. With, for example, three or
four grooves 18, which are distributed uniformly over the
circumference of the additional element 17, both effects can be
realized.
[0082] In the side wall 1 according to FIGS. 10 and 11, a distance
of the additional element 17 from the side wall 1 should be as
small as possible (apart from in the region of the groove 18 or the
grooves 18), in order to have as little influence as possible on
the heat removal from the hot side 3 to the cold side 7 of the side
wall 1. This can be achieved by appropriate matching of the
diameter of the additional element 17 to the diameter d4 of the
auxiliary cut-out 16. For example, a snug fit of the additional
element 17 in the auxiliary cut-out 16 may be realized. In this
case, after having been inserted into the auxiliary cut-out 16, the
additional element 17 can also be removed again from the auxiliary
cut-out 16. In this case, although the additional element 17 is not
connected cohesively to the side wall 1, it is still connected
directly. On account of the additional element 17, there still
remains a cavity, that is a space not filled with material, into
which the optical waveguide 9 can later be reversibly inserted,
that is when the additional element 17 is arranged in the auxiliary
cut-out 16, and which cavity is the useful cut-out 10.
[0083] Alternatively, a snug fit of the additional element 17 in
the auxiliary cut-out 16 may be achieved for example by the
diameter of the additional element 17 being minimally greater than
the diameter d4 of the auxiliary cut-out 16, as long as the
additional element 17 and the side wall 1 are at the same
temperature. In this case, for example, the additional element 17
may be cooled below the temperature of the side wall 1, so that the
additional element 17 has thermally shrunk slightly. In addition or
as an alternative, the side wall 1 may be heated. In this state,
the additional element 17 can then be readily inserted into the
auxiliary cut-out 16. The subsequent thermal expansion of the
additional element 17 and/or contraction of the side wall 1 has the
effect that the additional element 17 comes to bear against the
side wall 1 tightly and under pressure. It therefore cannot any
longer be removed from the auxiliary cut-out 16. The heat transfer
from the side wall 1 into the additional element 17 and vice versa
is therefore very good. In particular, the good heat transfer from
the side wall 1 into the additional element 17 prevents the side
wall 1 from being able to be heated independently of the additional
element 17, or the additional element 17 from being able to be
cooled down independently of the side wall 1. Otherwise, the above
statements made in relation to the case of a snug fit apply.
[0084] The additional element 17 should preferably be secured in
the auxiliary cut-out 16 against twisting. In the case of a snug
fit, twist prevention is obtained automatically by the pressure
under which the additional element 17 lies against the side wall 1.
In the case of a snug fit, corresponding securing elements may be
present, for example small wedges, are known to a person skilled in
the art.
[0085] The present invention has many advantages. In particular, it
is possible to produce a side wall 1 of a continuous casting mold
into which useful cut-outs 10 with a very small maximum useful
extent (for example diameter d3), seen transversely to the
longitudinal direction of the useful cut-outs 10, can be introduced
over the entire height H or width B or generally over a great
cut-out length L in the longitudinal direction of the useful
cut-outs 10. This enables optical waveguides 9 with or without a
protective casing 9' to be reversibly inserted into the useful
cut-outs 10. In particular, in the case of damage to an optical
waveguide 9, the damaged optical waveguide 9 can consequently be
readily exchanged. This exchangeability is of importance in
particular because the failure of an individual optical waveguide
leads to the failure of many individual temperature measuring
points. It is also possible first to introduce only the useful
cut-outs 10 into the side wall 1 and only subsequently, after the
forming of the useful cut-outs 10, to insert the optical
waveguides, 9 with or without a protective casing 9' into the
useful cut-outs 10.
[0086] Although the invention has been illustrated more
specifically and described in detail by the preferred exemplary
embodiment, the invention is not restricted by the examples
disclosed and other variations may be derived therefrom by a person
skilled in the art without departing from the scope of protection
of the invention.
LIST OF DESIGNATIONS
[0087] 1 Side walls [0088] 2 Liquid metal [0089] 3 Hot sides [0090]
3' Coating [0091] 4 Strand shell [0092] 5 Liquid core [0093] 6
Metal strand [0094] 7 Cold sides [0095] 8 Adjusting devices [0096]
9 Optical waveguide [0097] 9' Protective casing [0098] 10 Useful
cut-outs [0099] 11 Auxiliary cut-out (groove) [0100] 12 Groove base
[0101] 12' Further groove [0102] 13 Additional element (tube)
[0103] 13' Portions [0104] 13'' Guiding surfaces [0105] 14
Additional element (covering) [0106] 15 Filling material [0107] 16
Auxiliary cut-out (bore) [0108] 17 Additional element (rod) [0109]
18 Grooves of the rod [0110] a Distance [0111] B Width [0112] d1 to
d4 Diameter [0113] D Thickness [0114] H Height [0115] L Cut-out
length [0116] t Groove depth [0117] x Drawing-off direction
* * * * *