Bridging an interruption in production in a combined casting-rolling installation

Abstract

A method and a device that bridge an interruption in production in a combined casting-rolling installation to provide a combined casting-rolling installation for producing a hot-rolled finished strip, in which, in the case of an interruption, also thick precursor material having a thickness of >30 mm can be separated in a rapid and reliable manner from the next precursor material.

Claims

1. A method for production of a hot-rolled finished strip in a combined casting/rolling installation, wherein in a continuous operation a strand of an endless starting material passes through a facility for cutting and outward conveying at a transport speed in an uncut state, and the starting material is finish-rolled in a finishing train to form the finished strip, then cooled, cut and stored, wherein the following method steps are carried out in the facility for cutting and outward conveying so as to bridge an interruption in production in a section of the installation which is downstream of a material flow direction: a) accelerating at least one cutting edge of a first cutter, thereby initiating cutting of the endless starting material; b) clamping of the endless starting material by a clamping roller pair, wherein the clamping roller pair is arranged downstream of the first cutter in the material flow direction; c) once the endless starting material is clamped by the clamping roller pair, lifting of the endless starting material to a first height with a rotatable arm of a lifting apparatus by rotating the rotatable arm of the lifting apparatus, wherein the lifting apparatus is arranged in the material flow direction between the first cutter and the clamping roller pair; d) while the endless starting material is clamped by the clamping roller pair, cutting off a strand section from the starting material by the at least one cutting edge of the first cutter while the endless starting material is at the first height; e) while the endless starting material is clamped by the clamping roller pair, lifting of the strand section by the lifting apparatus to a second height higher than the first height; f) cutting the starting material that is passing the first cutter into scrap pieces by means of the first cutter; g) conveying the scrap pieces outward; h) removing the strand section until the combined casting/rolling installation is ready for operation again.

2. The method as claimed in claim 1, wherein the acceleration of the at least one cutting edge of the first cutter, the clamping of the endless starting material and the lifting of the endless starting material are initiated immediately after the occurrence of the interruption in the production.

3. The method as claimed in claim 1, wherein the acceleration of the at least one cutting edge of the first cutter, the clamping of the endless starting material and the lifting of the endless starting material are initiated simultaneously and immediately after the occurrence of the interruption in the production.

4. A method for the production of a hot-rolled finished strip in a combined casting/rolling installation, wherein in a continuous operation a strand of an endless starting material passes through a facility for cutting and outward conveying at a transport speed in an uncut state, and the starting material is finish-rolled in a finishing train to form the finished strip, then cooled, cut and stored, wherein the following method steps are carried out in the facility for cutting and outward conveying so as to bridge an interruption in production in a section of the installation which is downstream of a material flow direction: a) accelerating at least one cutting edge of a first cutter, thereby initiating cutting of the endless starting material; b) clamping of the endless starting material by a clamping roller pair, wherein the clamping roller pair is arranged downstream of the first cutter in the material flow direction; c) lifting of the endless starting material by a lifting apparatus, wherein the lifting apparatus is arranged in the material flow direction between the first cutter and the clamping roller pair; d) cutting off a strand section from the starting material by the at least one cutting edge of the first cutter; e) lifting of the strand section by the lifting apparatus; f) cutting the starting material that is passing the first cutter into scrap pieces by means of the first cutter; g) conveying the scrap pieces outward; h) removing the strand section until the combined casting/rolling installation is ready for operation again, wherein the lifting apparatus comprises: a two-part lifting arm having an inner section and an outer section, wherein the outer section is articulated with respect to the inner section, a lifting actuator for raising the inner section of the lifting arm, and a pivot drive for pivoting the outer section of the lifting arm, wherein as the endless starting material is lifted, the lifting actuator unfolds the inner section of the lifting arm, and wherein as the strand section is lifted, the outer section of the lifting arm is pivoted with respect to the inner section of the lifting arm in a clockwise direction, thereby further raising the outer section of the lifting arm.

5. The method as claimed in claim 4, wherein after lifting the endless starting material the inner section of the lifting arm includes an acute angle a from horizontal.

6. The method as claimed in claim 4, wherein after lifting the strand section the outer section is aligned parallel to the inner section of the lifting arm.

7. The method as claimed in claim 4, wherein after lifting the endless starting material the inner section of the lifting arm includes an acute angle a that is less than 90 from horizontal.

8. A combined casting/rolling installation for the production of a hot-rolled finished strip from an endless continuously cast starting material, comprising: a continuous casting installation, a facility for cutting and outward conveying in a material flow direction comprising a first cutter, a lifting apparatus and a clamping roller pair, a multi-stand finish rolling train for finish rolling the starting material to form the finished strip, a cooling section for cooling the finished strip, and a storage facility for conveying the finished strip outward, wherein the lifting apparatus comprises: a two-part lifting arm having an inner section and an outer section, wherein the inner section is articulated with respect to a support structure by means of a first joint and the outer section is articulated with respect to the inner section by means of a second joint, a lifting actuator for unfolding the inner section, and a pivot drive for pivoting the outer section in a clockwise direction with respect to the inner section of the lifting arm.

9. The combined casting/rolling installation as claimed in claim 8, wherein the lifting actuator is a first hydraulic cylinder for raising the inner section of the lifting arm.

10. The combined casting/rolling installation as claimed in claim 8, wherein the pivot drive is a second hydraulic cylinder which connects the outer section to the inner section of the lifting arm.

11. The combined casting/rolling installation as claimed in claim 10, wherein the second hydraulic cylinder is arranged substantially parallel to the inner section of the lifting arm.

12. The combined casting/rolling installation as claimed in claim 8, wherein the outer section of the lift arm comprises at least one tube aligned transversely to the material flow direction, wherein the at least one tube is arranged below the starting material when the lifting arm is not raised.

13. The combined casting/rolling installation as claimed in claim 8, wherein the first joint and the second joint have horizontal axes of rotation.

14. The combined casting/rolling installation as claimed in claim 13, wherein the second joint is arranged below the starting material when the lifting arm is not raised.

15. The combined casting/rolling installation as claimed in claim 8, wherein when the lifting arm is not raised a lowerable roller table is located below the lifting arm.

16. The combined casting/rolling installation as claimed in claim 8, wherein when the lifting arm is not raised a measuring roller is located above a passline of the starting material through the facility for cutting and outward conveying.

17. The combined casting/rolling installation as claimed in claim 16, wherein the measuring roller is connected to a displacement measuring system for measuring a deflection of the starting material.

18. The combined casting/rolling installation as claimed in claim 8, wherein the outer section of the lift arm comprises at least one cooled tube aligned transversely to the material flow direction, wherein the at least one cooled tube is arranged below the starting material when the lifting arm is not raised.

Description

SHORT DESCRIPTION OF THE DRAWINGS

(1) The above described characteristics, features and advantages of this invention and the manner in which these are achieved are more clearly and more precisely understandable in conjunction with the following description of multiple exemplary embodiments that are explained in detail in connection with the drawings. In the drawings:

(2) FIG. 1 shows a plan of a combined casting/rolling installation with a facility for cutting and outward conveying according to the prior art

(3) FIG. 2 shows a more detailed illustration of the facility for cutting and outward conveying shown in FIG. 1

(4) FIG. 3 shows a schematic elevation of a facility for cutting and outward conveying for a combined casting/rolling installation according to the invention

(5) FIG. 4a shows a detailed representation of the facility for cutting and outward conveying shown in FIG. 3 with the lifting apparatus 11 in the closed state, in other words it is not unfolded

(6) FIG. 4b shows a detailed representation of the facility for cutting and outward conveying shown in FIG. 3 with the lifting apparatus 11 in the closed, partially raised and fully raised state

(7) FIG. 5 shows a representation of the lifting arm of the lifting apparatus shown in FIG. 4a, 4b in the closed state with the lifting actuator

(8) FIG. 6a . . . 6d show a schematic representation of the different phases during raising of the lifting arm 28 of the lifting apparatus 11 shown in FIGS. 3 to 5.

DESCRIPTION OF THE EMBODIMENTS

(9) FIG. 1 shows a combined casting/rolling installation 1 known from WO 2009/121678 A1 for the production of a hot-rolled finished strip. In this case, a continuous slab or thin slab strand of a continuously cast starting material 3 is produced in a continuous casting machine 2. The starting material 3 is supported, guided and cooled in the arc-shaped strand guide of the continuous casting machine 2, so that the starting material 3 leaves the continuous casting machine 2 in the horizontal transport direction 7 on the roller table 4. The starting material 3 is then pre-rolled in a roughing train 5 and in the continuous operation of the combined casting/rolling installation 1 passes through a facility for cutting and outward conveying 6 in an uncut state, in other words as an endless starting strip. The starting strip is then heated to rolling temperature by a heating section 12 (for example an induction furnace), then descaled and finish-rolled in the finish rolling train 14 to form the finished strip. Following this, the finished strip is cooled in the cooling section 15, then cut by the flying cutter 16 and conveyed out of the casting/rolling compound installation 1 by the storage facility 17, in this case two coilers.

(10) FIG. 2 shows the facility for cutting and outward conveying 6 shown in FIG. 1 in more detail. If a malfunction occurs in a section of the installation downstream of the facility for cutting and outward conveying 6, a strand section 21 is cut off from the endless starting material 3 by the first cutter 9b and the strand section 21 is lifted by the lifting apparatus 11. The starting material 3 that follows on from the continuous casting machine 2 or the roughing installation 5 is cut into scrap pieces 19 by the first cutter 9b. The scrap pieces 19 can be picked up by a lowerable roller table 18 and are subsequently conveyed out of the installation. In addition, a second cutter 9ain this case a so-called pendulum cuttercan cut off longer sections 10 of starting material and convey them out of the installation by means of an outward conveying facility 8.

(11) FIG. 3 shows a facility for cutting and outward conveying 6 for a combined casting/rolling installation 1 according to the invention. The second cutter 9a is a pendulum cutter, whereby sections of starting material 10 can be cut out of the endless starting material 3 and conveyed out of the installation by means of the outward conveying facility 8. The first cutter 9b, on the other hand, is a drum cutter with two drums. If a malfunction occurs in a part of the installation downstream of the facility for cutting and outward conveying 6, for example a flyer (usually just called a cobble) in the finish rolling train, or a problem occurs in the cooling section 15 or the storage facility 17, the first cutter 9b is accelerated immediately after the interruption in the production is detected, thus initiating the cutting of the endless starting material 3. It should be noted here that the drums of the first cutter 9b do not run continuously, but must be accelerated from a standstill. Both drums carry cutting edges for cutting off the starting material 3. Depending on the drive power of the first cutter, the mass moments of inertia of the drums and the transport speed of the starting material 3, the acceleration of the first cutter 9a takes a certain time. Thus, the starting material cannot be cut immediately after the interruption in the production is detected. Subsequently, the starting material 3, which is still continuous, is clamped by a clamping roller pair 23. The pair of clamping rollers which can be hydraulically adjusted to the starting material is arranged downstream of the lifting apparatus 11. By clamping the starting material 3, the material is squeezed so that it can subsequently be bent more easily. Subsequently, the endless starting material 3 is lifted by means of the lifting apparatus 11. Typically, a strand section 21 is cut off from the endless starting material 3 only after the starting material 3 has been lifted, whereby the starting material 3 that is following on is separated from the strand section 21. The cutting off is performed by cutting edges 27 of the first cutter 9b. When the lifting arm 28 of the lifting apparatus 11 is not raised, a lowerable roller table 18 is arranged below the lifting arm 28.

(12) FIG. 4a shows again in more detail the area between the first cutter 9b and the clamping roller pair 23 shown in FIG. 3. When the lifting arm 28 is not raised, a measuring roller 26 is arranged above the passline 34 of the starting material 3, which measures the deflection of the starting material 3 by means of a measuring system 33 shown in FIG. 5. The measuring roller 26 and the displacement measuring system 33 can be used to control the main drives of the downstream finish rolling train 14 so that the starting material is almost tension-free in the continuous operation between the roughing mill 5 and the finish rolling train 14.

(13) FIG. 4b shows in more detail the different phases during the lifting of the starting material or the strand section. After acceleration of at least one cutting edge of the first cutter 9b and the clamping of the endless starting material 3 by the clamping roller pair 23, first only the inner section 28b of the lifting arm 28 is raised by means of a lifting actuator 29 (for example a hydraulic cylinder) shown in FIG. 5 from the starting position which is not raised (see also FIG. 6a). As a result, the inner section 28b of the lifting arm 28 includes an acute angle <90 with the horizontal (see also FIG. 6b). The pivot drive 30, which is responsible for pivoting the outer section 28a of the lifting arm 28, remains unpressurized during lifting, so that the outer section 28a is not collinearly aligned with the inner section 28b. This measure dramatically reduces the force or torque required to lift the starting material 3. Typically, after the starting material 3 is cut off by the first cutter 9b, the inner section 28b of the lifting arm 28 is further raised so that it includes a right angle to the horizontal (see also FIG. 6c). Only then is the outer section 28a of the lifting arm 28 pivoted by the pivot drive 30 in a clockwise direction so that the outer section 28a is aligned collinearly with the inner section 28b (see also FIG. 6d).

(14) FIG. 5 shows the connection of the lifting actuator 29 to the lifting arm 28 as well as the measuring roller 26 and the displacement measuring system 33.

(15) FIG. 6a shows the state of the facility for cutting and outward conveying 6 in the continuous operation of the casting/rolling compound installation. In this case, the lifting arm 28 of the lifting apparatus 11 is not raised and the passline 34 of the starting material 3 runs horizontally. After an interruption in the production has been detected in a section of the installation which is downstream of the facility for cutting and outward conveying 6, the cutting of the endless starting material 3 by means of the first cutter 9b is initiated and the clamping roller pair 23 is clamped (see the arrow in the case of the clamping roller pair, which represents the clamping).

(16) In FIG. 6b, the starting material 3 is already clamped by the clamping roller pair 23 and the inner section 28a of the lifting arm is raised. Since the starting material 3 is still in an uncut state, the cooled tube 20, which lies below the passline when the lifting apparatus 11 is in the closed state, carries the starting material 3 upwards. The pivot drive 30 is depressurized during the raising so that the outer section 28a of the lifting arm is not colinear with the inner section 28b.

(17) FIG. 6c shows the situation after the starting material 3 has been cut off by the first cutter 9b. As a result of the cutting, a strand section 21 is cut off from the starting material 3 and said strand section is substantially not tensioned. After the cutting, it is easily possible to completely raise the inner section 28b of the lifting arm 28 so that the inner section 28b of the lifting arm 28 includes an angle approximately at a right angle to the horizontal.

(18) In FIG. 6d, the outer section 28a of the lifting arm 28 is pivoted by the pivot drive 30 shown in FIG. 6b in a clockwise direction so that the outer and inner section 28a, 28b of the lifting arm 28 are collinearly aligned. As a result, the strand section 21 is raised even further.

(19) Although the invention is further illustrated and described in detail by means of the preferred exemplary embodiments, the invention is not limited by the disclosed examples and other variations may be derived therefrom by the person skilled in the art without abandoning the protective scope of the invention.

LIST OF REFERENCE CHARACTERS

(20) 1 Combined casting/rolling installation 2 Continuous casting machine 3 Starting material 4 Roller table 5 Roughing train 6 Facility for cutting and outward conveying 7 Material flow direction 8 Outward conveying facility 9a Second cutter 9b First cutter 10 Starting material section 11 Lifting apparatus 12 Heating section 13 Descaling installation 14 Finish rolling train 15 Cooling section 16 Flying cutter 17 Storage facilities 18 Lowerable roller table 19 Scrap piece 20 Tube 21 Strand section 22 Crane 23 Clamping roller pair 24 Lifting drive of the lowerable roller table 25 Drive rollers 26 Measurement roller 27 Cutting edge 28 Lifting arm 28a 28b Outer section and inner section of the lifting arm 29 Lifting actuator 30 Pivot drive 31 First joint 32 Second joint 33 Displacement measuring system 34 Passline Angle