The invention relates to a furnace for heating metal strips according to the generic terms of Claim 1, a device for producing metal strips by continuous casting and rolling according to the generic terms of Claim 12, and a method for producing metal strips by continuous casting and rolling according to the generic terms of Claim 17.
The present invention can be used in casting-rolling plants, in which a finished product in the form of a metal strip is produced either discontinuously or in continuous operation from liquid metal. In particular, the invention can be used in casting-rolling plants for producing metal strips in the form of flat-rolled steel, wherein a furnace of such a casting-rolling plant is formed by a roller hearth furnace, for example.
In commonly known casting-rolling plants, it could be provided that, when a malfunction occurs, material is discharged laterally from a roller hearth furnace. For this purpose, so-called tracks can be used, which swivel or are displaced in parallel. However, a continuous material string or metal strip can only be discharged from the roller hearth furnace if the piece of material to be discharged first is separated. In this regard, the state of the art has the disadvantage that, in order to separate the metal strip and to subsequently discharge a separated segment of the metal strip laterally, the material must be moved in the direction of or against its conveying direction in close proximity to a furnace. This results in the requirement that the material must be able to be conveyed or moved on the transport apparatuses before or after the (roller hearth) furnace. However, in particular in the case of casting-rolling plants, which operate continuously, the space on the transporting apparatuses in close proximity to the furnace frequently is occupied by material or strip when a malfunction occurs and can therefore not be used. Thus, the process has to be delayed until these transporting apparatuses are free again. However, the metal strip located outside of the roller hearth furnace at that time cools down during this waiting period, which could then lead to problems with the further production process.
The problem underlying the invention is to optimize the production of metal strips by continuous casting and rolling in such a manner that it is possible to unload or discharge separated segments of the metal strip without requiring additional space on the transporting apparatuses before or after a furnace.
The aforementioned problem is solved by a furnace with the characteristics listed in Claim 1, furthermore by a device with the characteristics listed in Claim 12, and furthermore by a method according to claim 17. Advantageous developments of the invention are defined in the dependent claims.
A furnace according to the present invention serves to heat metal strips and comprises a housing, wherein a metal strip can be transported through the housing in a conveying direction. A first internal cutting apparatus and a second internal cutting apparatus are provided inside the housing. The second internal cutting apparatus is arranged at a distance to the first internal cutting apparatus and arranged downstream from the first internal cutting apparatus in a conveying direction of the metal strip. Said internal cutting apparatuses in particular can be actuated simultaneously such as to separate a segment of the metal strip located between the internal cutting apparatuses inside the furnace.
The present invention furthermore provides a device for producing metal strips by continuous casting and rolling, wherein such a device comprises a casting machine, a furnace through which a metal strip can be transported in a conveying direction, a first external cutting apparatus and a second external cutting apparatus, wherein the first external cutting apparatus is arranged upstream of the furnace and the second external cutting apparatus is arranged downstream of the furnace, in the conveying direction of the metal strip, and at least one rolling mill. Herein, the furnace is formed by the aforementioned furnace according to the present invention.
The present invention furthermore provides a method for producing metal strips by continuous casting and rolling, wherein a metal strip first is cast in a casting machine, then, depending on plant configuration, is rolled, subsequently is transported through a furnace in a conveying direction and fed into a downstream rolling mill. In case of a production malfunction, a segment of the metal strip is separated in a discharge section inside a housing of the furnace and is subsequently discharged from the discharge section of the furnace, in particular discharged laterally out of the furnace.
The invention is based on the essential finding that a metal strip, in particular when a malfunction occurs, can be severed or separated immediately inside the housing of the furnace, followed by a discharge of such a separated segment of the metal strip from the furnace. The first internal cutting apparatus and the second internal cutting apparatus are provided inside the housing of the furnace for this purpose. Said internal cutting apparatuses in particular can be actuated simultaneously such as to separate a segment of the metal strip located between the internal cutting apparatuses inside the furnace. Alternatively, these two internal cutting apparatuses can also be actuated consecutively, which then also results in the separating of a segment of the metal strip located between the internal cutting apparatuses. In this respect, such a separating of a segment of the metal strip inside the furnace can be conducted regardless whether a transporting apparatus or a roller table of a casting-rolling plant is occupied outside of the furnace and in close proximity to the same. This makes it possible, in particular in the case of a malfunction, to quickly discharge separated segments of the metal strip, whereby a cooling off of the material outside of a furnace is prevented or at least reduced.
In an advantageous development of the invention, the housing of the furnace has a discharge section, from which a separated segment of the metal strip can be discharged in a discharging direction. Herein, the internal cutting apparatuses are designed such that they separate the metal strip at an angle to the conveying direction inside the furnace, such that a separated segment of the metal strip can then be conveyed out of the furnace or its discharge section without entanglement or similar complications. Said cutting of the metal strip at an angle inside the furnace is conducted in such a manner that the cuts generated by the internal cutting apparatuses confine respective angles in the metal strip in relation to the discharging direction, which are between 3′-30′, preferably between 5′-15°. Herein, the angle of the cut generated with the first internal cutting apparatus is inclined against the conveying direction of the metal strip, whereas the angle of the cut generated with the second internal cutting apparatus is inclined in the direction of the conveying direction of the metal strip. Due to this, the cuts extend in the shape of the sides of a trapezoid open to the outside, or an “open wedge,” thus facilitating the unloading or discharging of a separated segment of the metal strip from the furnace.
Preferably, the discharging of a separated segment of the metal strip from the furnace is, according to the present invention, conducted in a lateral section of said furnace, that is, laterally out of the housing of the furnace. For this purpose, the discharge section of the housing can have an opening, such that a separated segment of the metal strip can be unloaded from the furnace through this opening.
According to an alternative embodiment of the invention, it also is possible to discharge a separated segment of the metal strip out upwardly.
During the operation of the furnace or of a device for producing metal strips by continuous casting and rolling, heat loss can be prevented by means of a heat-insulating hood, which is provided adjacent to the opening in the discharge section of the housing. Should a malfunction occur and—as explained previously—should a separated segment be discharged from the furnace, the heat-insulating hood is raised or opened during this process, for example, by use of an automatic hatch or similar cover, which is pushed by the segment of the metal strip being unloaded or is operated by a motor.
According to an advantageous embodiment of the invention, a discharge device is provided in the area of the opening of the housing, by means of which a separated segment of a metal strip is discharged from the housing of the furnace. Such a discharge device can comprise rollers arranged in the housing of the furnace, for example, which can be raised relative to an adjacent roller table to discharge a separated segment of the metal strip from the housing. Additionally and/or alternatively, the discharge device can have a support arm, a track element, a sliding device and/or a tilt apparatus, by means of which a separated segment of the metal strip can be discharged from the housing of the furnace.
If the discharge device is provided in the form of a track element, such a track element can be designed between the two internal cutting apparatuses and can be moveable in the discharging direction. Therein, the joint of the track element to the housing of the furnace can be designed at a right angle. If the joint is designed at an angle—as seen in a top view of the furnace—a lateral movement or sliding of the track element along or in the discharging direction is facilitated.
In an advantageous development of the invention, at least the first internal cutting apparatus or at least the second internal cutting apparatus, preferably also both internal cutting apparatuses, are designed in the form of a torch, in the form of a laser cutting device or in the form a purely mechanical cutting apparatus. Regardless of these various options for the design of the internal cutting apparatuses, it always is ensured that the cuts generated by said internal cutting apparatuses extend at an angle in relation to the discharging direction and—as explained previously—confine an angle between 3°-30°, preferably between 5°-15°. Such inclined cuts facilitate the discharging of separated segments of the metal strip from the furnace.
In the device according to the invention, the discharging of separated segments of the metal strip furthermore is optimized by the fact that a roller table for unloading, a chute and/or a stacking apparatus are arranged adjacent to the lateral opening in the housing of the furnace. These make it possible to consecutively unload multiple pieces of material, that is, separated segments of the metal strip, out of the furnace. Thereby, a cooling down of the strip material in a casting-rolling plant is prevented or at least reduced.
In an advantageous development of the device according to the invention, a crushing apparatus can be provided adjacent to the lateral opening in the housing of the furnace, by means of which crushing apparatus segments of the metal strips, which have been unloaded from the furnace, can be crushed. Such a crushing apparatus can be designed in the form of a scrap shear, for example. Hereby, multiple separated segments of the metal strip can be crushed after they have been unloaded out of the housing of the furnace, in particular unloaded laterally, whereby the required space for receiving these unloaded segments is advantageously reduced.
The present invention makes it possible in an advantageous manner to quickly unload or convey strip material out of a furnace, in particular one in the form of a roller hearth furnace, in the case of a malfunction, in particular the malfunction of a casting-rolling plant, wherein said unloading or conveying quickly restores the production readiness of the casting-rolling plant after the malfunction is rectified.
Further advantages and aspects of the present invention can be found in the following exemplary embodiments, which are described in detail using a schematically simplified drawing.
The drawings show:
In the following, preferred embodiments of an inventive device 1 for producing metal strips by continuous casting and rolling, an associated furnace 10 and a corresponding method are explained in detail in reference to
The inventive furnace 10 serves to heat metal strips and comprises a housing 11, wherein a metal strip 12 can be transported through the housing 11 in a conveying direction FR. A first internal cutting apparatus 14 and a second internal cutting apparatus 16 are provided inside the housing 11. Herein, the second internal cutting apparatus 16 is arranged at a distance to the first internal cutting apparatus 14 and arranged downstream from the first internal cutting apparatus 14 in a conveying direction FR of the metal strip 12.
The furnace 10 is shown schematically in a side view in
The two internal cutting apparatuses 14 and 16 of the furnace 10 can be designed such that they can be actuated simultaneously, thereby separating a segment 18 of the metal strip 12 located between the internal cutting apparatuses 14 and 16 inside the furnace 10. Alternatively, these two internal cutting apparatuses 14 and 16 can also be actuated consecutively, which then also results in the separating of a segment of the metal strip 12 located between the internal cutting apparatuses. The top view of the furnace 10 or of the device 1 according to
The internal cutting apparatuses 14 and 16 are designed such that the cuts T1 and T2 generated by the same in the metal strip 12 respectively extend at an angle and respectively confine an angle between 3°-30°, preferably between 5°-15°, in relation to the discharge direction AR (cf.
A discharge device 24 (
The internal cutting apparatuses 14 and 16 of the furnace 10 preferably are designed as torches and will be referred to as torches in the following, wherein this reference term does not constitute a limitation.
The representation according to
The top view according to
A fault monitoring system 8 (cf.
In
The operating principle of the present invention is explained in the following in reference to
In step 1 according to
In step 2 according to
In step 4 according to
In step 5 according to
In step 6 according to
The sequence of steps described above in reference to
Number | Date | Country | Kind |
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10 2016 222 692.4 | Nov 2016 | DE | national |
10 2017 210 850.9 | Jun 2017 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2017/078971 | 11/10/2017 | WO | 00 |