U.S. patent application number 13/813186 was filed with the patent office on 2013-10-17 for melt charging system for strip casting.
This patent application is currently assigned to SMS SIEMAG AKTIENGESELLSCHAFT. The applicant listed for this patent is Joerg Bausch, Hellfried Eichholz, Reiner Puerling, Jochen Schlueter, Karl-Heinz Spitzer, Jochen Wans. Invention is credited to Joerg Bausch, Hellfried Eichholz, Reiner Puerling, Jochen Schlueter, Karl-Heinz Spitzer, Jochen Wans.
Application Number | 20130269905 13/813186 |
Document ID | / |
Family ID | 44629759 |
Filed Date | 2013-10-17 |
United States Patent
Application |
20130269905 |
Kind Code |
A1 |
Bausch; Joerg ; et
al. |
October 17, 2013 |
MELT CHARGING SYSTEM FOR STRIP CASTING
Abstract
A melt charging system for the horizontal strip casting of a
molten metal with a run-out element, in particular with a nozzle
(9), is characterized in that at least one heating device (21, 22;
28) is arranged in the region of the run-out element for heating up
the run-out element.
Inventors: |
Bausch; Joerg; (Duesseldorf,
DE) ; Puerling; Reiner; (Hoenningen-Liers, DE)
; Schlueter; Jochen; (Dortmund, DE) ; Wans;
Jochen; (Meerbusch, DE) ; Spitzer; Karl-Heinz;
(Clausthal-Zellerfeld, DE) ; Eichholz; Hellfried;
(Ilsede, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Bausch; Joerg
Puerling; Reiner
Schlueter; Jochen
Wans; Jochen
Spitzer; Karl-Heinz
Eichholz; Hellfried |
Duesseldorf
Hoenningen-Liers
Dortmund
Meerbusch
Clausthal-Zellerfeld
Ilsede |
|
DE
DE
DE
DE
DE
DE |
|
|
Assignee: |
SMS SIEMAG
AKTIENGESELLSCHAFT
Duesseldorf
DE
|
Family ID: |
44629759 |
Appl. No.: |
13/813186 |
Filed: |
July 29, 2011 |
PCT Filed: |
July 29, 2011 |
PCT NO: |
PCT/EP2011/063098 |
371 Date: |
July 2, 2013 |
Current U.S.
Class: |
164/507 ;
164/418 |
Current CPC
Class: |
B22D 11/0631 20130101;
B22D 11/0642 20130101; B22D 11/10 20130101 |
Class at
Publication: |
164/507 ;
164/418 |
International
Class: |
B22D 11/10 20060101
B22D011/10 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2010 |
DE |
10 2010 033 018.3 |
Claims
1-10. (canceled)
11. Melt charging system for horizontal strip casting of a molten
metal (3) with a run-out element, in particular with a nozzle (9,
30) and with at least one heating device (21, 22; 28) for heating
the run-out element arranged in the region of the run-out element,
characterized in that the heating device is arranged adjacent to
the run-out element and comprises at least one pore burner.
12. Melt charging system for horizontal strip casting of a molten
metal (3) with a run-out element, in particular with a nozzle (9,
30) and with at least one heating device (21, 22; 28) for heating
the run-out element arranged in the region of the run-out element
in recesses or grooves in the bottom and/or cover, characterized in
that the heating device comprises heating rods.
13. Melt charging system according to claim 12, characterized in
that the heating rods (23, 27) are designed as carbide heating
rods, particularly, as lithium carbide or silicon carbide heating
rods.
14. A combustion-engined setting tool according to claim 11
characterized in that the run-out element is formed at least
partially from a fire-resistant ceramic.
15. Melt charging system according to claim 11, characterized in
that the heating device (21, 22; 28) is arranged or integrated in a
bottom, in side walls, in a weir, dam, a run-out and/or in a cover
of the run-out element or of the nozzle.
16. Melt charging system according to claim 11, characterized in
that the heating device (24; 28) is surrounded by ceramic
components (23, 27).
17. Melt charging system according to claim 11, characterized in
that the heating device comprises inductive heating means.
18. Melt charging system according to claim 12, characterized in
that the run-out element is formed at least partially from a
fire-resistant ceramic.
19. Melt charging system according to claim 12, characterized in
that the heating device (21, 22; 28) is arranged or integrated in a
bottom, in side walls, in a weir, dam, a run-out and/or in a cover
of the run-out element or of the nozzle.
20. Melt charging system according to claim 12, characterized in
that the heating device comprises inductive heating means.
Description
[0001] The invention relates to a melt charging system for the
horizontal strip casting of a molten metal with a run-out element,
in particular with a casting nozzle for the free overflow of the
molten metal, referred to as "nozzle" further below.
[0002] The horizontal strip casting of metals, also referred to as
Direct Strip Casting and BCT (Band Casting Technology), is used,
for example, in the case of steel, for example, with a
near-final-dimension casting in combination with an offline or an
inline rolling The forming or rolling step here has the purpose of
both reducing the thickness and also of restructuring, i.e.,
recrystallizing. It is a method intended for the production of a
wide hot rolled strip for steel alloys.
[0003] In strip casting, liquid steel is charged through a feed
system with an appropriately designed nozzle onto a circulating
conveyor belt cooled with water from below. The melt addition in
the horizontal strip casting occurs via the melt charging vessel or
charging system. Here, the melt flows through a filling region and
subsequently a run-out region, before it reaches the conveyor belt
through a ceramic component, for example, a nozzle with free
overflow. The conveyor belt is driven and guided by two deflection
rollers. The melt charged onto the conveyor belt solidifies
completely while still in the region of the primary cooling. After
the solidification, the strip moves for inline rolling into the
rolling stand. After the inline rolling and an additional cooling
process, the strip is wound. Such a casting method for strip
casting is known from DE 198 52 275 A1.
[0004] It is known to preheat the melt charging system in order to
prevent the freezing of the solidifying metal onto the run-out
element (nozzle). However, in this technology it is impossible to
prevent the run-out element, after the completion of the preheating
process, from being no longer sufficiently hot, and freezing on of
the metal to be cast occurs. This leads to an uneven melt stream
and to defects in the cast strip profile and on the surfaces of the
cast products. Similarly, detachment of frozen on portions during
the casting also leads to non-stationary states with regard to the
flow and the surface quality. A very long preheating time in the
region of the metal charging in the melt charging system, i.e., up
to the time immediately before the entry of the melt, cannot be
carried out as a result of the melt being rendered inert by means
of an inert gas, which also occurs in the region of the metal
charging.
[0005] The problem of the invention is to avoid the disadvantages
of the state of the prior art and in particular the freezing on of
the solidifying metal at the outlet of the run-out element
(nozzle).
[0006] According to the invention, this problem is solved in a melt
charging system of the type mentioned at the start in that, in the
region of the run-out element, at least one heating device for
heating the run-out element is arranged.
[0007] According to the invention, an active heating of the run-out
element, i.e., in particular the nozzle, is provided. Similarly,
the region near the nozzle can also be heated.
[0008] Advantageous variants of the invention can be obtained from
the dependent claims.
[0009] A particularly suitable embodiment of the invention provides
for the run-out element itself to be provided with the heating
device, or for the heating device to be arranged adjacently to the
run-out element.
[0010] The run-out element is preferably designed partially from a
fire-resistant ceramic.
[0011] Advantageously, the heating device is designed as a gas
heater and/or an electrical heater.
[0012] It is also advantageous to provide that the heater is
arranged or integrated in a bottom, in side walls, in a weir, a
dam, an overflow and/or a cover of the run-out element or of the
nozzle.
[0013] The heating device is preferably arranged, in the form of
heating rods, in recesses or grooves in the bottom and/or in the
cover.
[0014] In an additional advantageous embodiment, the heating device
is surrounded by ceramic components. They can be used in different
geometries.
[0015] Advantageously, the heating rods are designed as carbide
heating rods, in particular as lithium carbide or as silicon
carbide heating rods.
[0016] When the heating device comprises at least one pore burner,
it is possible to provide a heater that can be regulated in a
continuously variable manner and rapidly over broad ranges. The
pore burner can be operated with a liquid heating agent, but
preferably with a gas. Here, in the case of simultaneous feeding of
a combustible fluid and of air, a combustion reaction occurs in a
ceramic foam. The pore burner can thus fill a nozzle bottom part
and/or top part completely or partially in terms of surface area.
Owing to the high surface power density that can be achieved with
the pore burner, the latter can be operated as a compact burner
unit. Since the burner power can be adjusted in a continuously
variable manner, it is possible to provide the burner heat in a
finely dosed manner as required respectively in the process, in
order to adapt the nozzle surfaces to the melting parameters
required in the respective melting process.
[0017] In a further embodiment, inductive heating means are
advantageously used, for example, WS "Inducer" Company RHI.
[0018] It is particularly advantageous to use a system with an
induced mean frequency of approximately 10 kHz. The coil geometry
should be adapted to the ceramic component to be heated, in order
to ensure a rapid and even heating. The ceramic should moreover
have a sufficient electrical conductivity in order to allow,
together with the required power density, a brief heating time of
preferably approximately 10 minutes.
[0019] The melt charging system according to the invention
advantageously also provides a unit for feeding an inert gas on the
line section of the metal strip to be cast in the region of the
run-out element.
[0020] According to the invention, different technologies can be
integrated, particularly
[0021] 1.) Heating elements integrated in ceramic or as substitute
for ceramic
[0022] 2.) Pore burner, as described above, and
[0023] 3.) Induction for heating the run-out element, in particular
the nozzle. If the nozzle is designed as a ceramic element, a
ceramic temperature of approximately 1100.degree. C. is sought for
casting a steel melt. If the nozzle cover or the nozzle roof is
replaced by a heated component, the heat heats the ceramic via
radiation. The heating elements can also be integrated in the cover
of the nozzle, particularly in the region of the overflow.
[0024] If the nozzle bottom is replaced by a heated component, the
radiation also heats the ceramic. All that needs to be done is take
suitable cooling measures for the conveyor belt by means of which
the metal strip is transported for removal. Similarly, the heating
elements can be integrated in the bottom of the nozzle,
particularly in the region of an overflow, in a dam, a weir or in
the sidewalls of the nozzle.
[0025] Overall, the advantage provided by the invention is also
that the casting process is more robust with regard to time and
also temperature losses. The casting can here also occur over a
longer time period.
[0026] The invention is explained in greater detail below in
embodiment examples.
[0027] FIG. 1 shows a diagrammatic side view of an installation for
strip casting,
[0028] FIG. 2 shows a cross-sectional view of a run-out region
provided with heating elements in an installation for strip
casting, and
[0029] FIG. 3 is a perspective view, with partial cross section, of
a nozzle in an installation for strip casting.
[0030] A strip casting installation 1 (FIG. 1) for casting a steel
strip or a strip made of another metal comprises a feed system for
the liquid metal with an oven 2 which initially contains a melt
3.
[0031] Via a stopper rod 4, the oven 2 can be opened downward to a
tapping channel 5. Here, the stopper rod 4 is mounted in the closed
state opposite a sealing ring 6.
[0032] The melt flows out of the tapping channel 5 into a
preferably also heated or insulated charging vessel 7. From the
latter, the melt is through an outlet channel 8 which ends in an
outlet run-out region, particularly in a nozzle 9.
[0033] The nozzle 9 is provided with a dam 10 and with a weir 11 in
order to channel the stream of the melt. In the region of the
outlet of the nozzle 9, a gas nozzle 12 is provided, which
generates a stream of an inert gas against the direction of flow of
the melt, in order to distribute the melt, preferably also
transversely to the casting direction, and/or in order to prevent
the surface corrosion of the solidifying melt.
[0034] Said melt forms a metal strip 14 on an endless conveyor belt
13. The conveyor belt 13 runs over a deflection or drive roller 15.
Furthermore, the conveyor belt 13 is led over supporting rollers 16
and/or a honeycomb grid. Between the latter, spraying nozzles 17
are arranged, which spray a cooling medium collected from a basin
18 onto the bottom side of the conveyor belt 13 in order to
solidify the metal strip 14.
[0035] Preferably, on the two small sides of the belt of the
conveyor belt 13--not shown here--shaping segments are provided
that move along with said conveyor belt, and are arranged with
mutual overlap or closely adjacent to each other, in order to
prevent the run-out of the solidifying metal. The spacing of the
segments is determined either by the width of the conveyor belt 13
or it is adjustable in accordance with the desired width.
[0036] A nozzle 9 constructed like nozzle 9 and therefore provided
with the same reference numeral (FIG. 2) is provided at several
places with heating elements, in order to make available, by way of
the surfaces abutting against the metal melt, a constant ambient
temperature for the melt. Preferably, heating devices are provided
both in the nozzle top part 19 and also in the nozzle bottom part
20. In the nozzle top part 19, two heating devices 21, 22 are
arranged one after the other in the direction of flow of the melt.
Each one of the heating devices 21, 22 comprises a heating rod 24
housed in a ceramic pipe 23. A heating rod 26 is also arranged in a
front weir 25 of the nozzle 11. The weir here is preferably
designed inside as a ceramic pipe. The heating rod 26 can be
integrated in the ceramic pipe. The weir 25, on the outlet side,
controls the flow of the melt out of the nozzle 9.
[0037] Similarly, in the nozzle bottom part 20, in a ceramic pipe
27, a heating rod 28 is accommodated. The heating rods 24, 26, 28
are produced, for example, from silicon carbide or lithium
carbide.
[0038] In a further embodiment of a nozzle 30 (FIG. 3) having a
bottom part 31 and a top part 32, heating rods 33, 34, as ohmic
resistance heaters, are formed on the top side and they extend
transversely to the direction of flow of the melt which is exiting
the nozzle via a dam 35.
[0039] The nozzle top and bottom parts 19, 20 and 31, 32 are made
completely from a fire-resistant ceramic, for example. In this case
as well, the fire-resistant ceramic can be provided with recesses
into which the ceramic jacketed heating elements, such as the
heating rods 33, 34, are introduced.
[0040] On the other hand, depending on the melt temperature of the
metal to be cast, the nozzle top and bottom parts 19, 20 and 31, 32
can also be made of a metal having a sufficiently high melting
temperature.
[0041] Thus, when the metal to be cast is tin, zinc or aluminum or
an alloy of said metals, the nozzle top and bottom parts 19, 20 and
31, 32 can also be made entirely or completely of steel, for
example, a stainless steel with properties that are adapted to the
use, particularly with regard to corrosiveness, wherein, in this
case as well, heating rods with ceramic jacketing can be introduced
into appropriate recesses in the nozzle top and bottom parts.
[0042] The arrow S in FIGS. 2 and 3 denotes the direction of flow
of the melt.
LIST OF REFERENCE NUMERALS
[0043] 1 Strip casting installation
[0044] 2 Oven
[0045] 3 Melt
[0046] 4 Stopper rod
[0047] 5 Tapping channel
[0048] 6 Sealing ring
[0049] 7 Charging vessel
[0050] 8 Outlet channel
[0051] 9 Nozzle/run-out element
[0052] 10 Dam
[0053] 11 Weir
[0054] 12 Gas nozzle
[0055] 13 Conveyor belt
[0056] 14 Metal strip
[0057] 15 Deflection or drive roller
[0058] 16 Supporting rollers
[0059] 17 Spray nozzles
[0060] 18 Basin
[0061] 19 Nozzle top part
[0062] 20 Nozzle bottom part
[0063] 21 Heating device
[0064] 22 Heating device
[0065] 23 Ceramic pipe
[0066] 24 Heating rod
[0067] 25 Weir
[0068] 26 Heating rod
[0069] 27 Ceramic pipe
[0070] 28 Heating rod
[0071] 29 --
[0072] 30 Nozzle
[0073] 31 Bottom part
[0074] 32 Top part
[0075] 33 Heating rod
[0076] 34 Heating rod
[0077] 35 Dam
[0078] S Arrow for the direction of flow of the melt
* * * * *