Abstract
A method and device for producing hot-rolled products in a combined continuous casting and rolling system includes a device for separating and removing. In order to overcome a disruption in production in a part of the system located downstream of the device for separating and removing, the method includes: (a) separating the endlessly produced precursor material into a strand portion with shears; (b) clamping the strand portion; (c) raising the trailing part of the strand portion from the roller table by a raising device, so that the strand portion is drawn away from the shears in the direction of transport; (d) cutting the precursor material into a precursor material portion with the shears; (e) removing the precursor material portion from the roller table, and removing the strand portion until the combined continuous casting and rolling system is ready to operate again.
Claims
1. A method for manufacturing hot-rolled strip in a continuous casting-rolling installation comprising: 1) performing an endless operation comprising solidifying a strand with slab or thin slab cross-section of an endless strand-cast preliminary material, after complete solidification of the strand, passing the strand uncut through a cutting up and delivery device on a roller table in a transport direction, subsequently hot-rolling the strand in a finishing rolling train, then cooling down, cutting and storing the hot rolled material or strip; 2) for bridging an interruption in production in a part of the installation which is located downstream in the transport direction from the cutting up and delivery device, the method further comprising performing the following steps in the cutting up and delivery device: a) cutting off the endless strand-cast preliminary material into a strand portion by using shears; b) clamping the strand portion by a clamping device pressing a pair of opposing rollers onto the strand portion downstream of the strand raising device in the transport direction, thereby immobilizing the strand portion against movement in the transport direction; c) raising a trailing tail part of the strand portion from the roller table using a raising device for pulling the tail part of the strand portion away from the shears in the transport direction; d) cutting the preliminary material that is passing the shears to form a preliminary material portion using the shears; e) delivering the preliminary material portion from the rolling table using a delivery device, and f) removing the strand portion until the operational readiness of the continuous casting-rolling installation is restored.
2. The method as claimed in claim 1, further comprising raising the tail part of the strand portion in a vertical direction using a raising bar.
3. The method as claimed in claim 1, further comprising during the cutting of the preliminary material, the shears cutting off the passing preliminary material into preliminary material portions.
4. The method as claimed in claim 3, further comprising during the delivering, pushing the preliminary material portion away transversely to the transport direction.
5. The method as claimed in claim 3, wherein the cutting off of the passing preliminary material is into the portions having a length of 8 to 14 m.
6. The method as claimed in claim 1, further comprising during the removing, lifting the strand portion in a vertical direction using a crane.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Further advantages and features of the present invention emerge from the description given below of the non-restrictive exemplary embodiments, wherein reference is made to the following figures, in which:
(2) FIG. 1 shows a schematic diagram of a combined casting-rolling installation for fully-continuous endless operation
(3) FIG. 2 shows a schematic diagram of a cutting up and delivery device in accordance with the prior art
(4) FIGS. 3A and 3B respectively show a sectional view and plan view in a schematic diagram of a first form of embodiment of the inventive cutting up and delivery device
(5) FIG. 4A . . . 4F show a schematic diagram of the steps in the cutting up and delivery device for bridging an interruption in production
(6) FIGS. 5A and 5B respectively show a sectional view and plan view in a schematic diagram of a second embodiment of the inventive cutting up and delivery device
DESCRIPTION OF THE EMBODIMENTS
(7) FIG. 1 shows a combined casting-rolling installation 1 known from WO 2009/121678 A1. In normal operation a continuous casting machine 2 continuously produces a preliminary material 3 in the form of a thin slab strand, which is transported by a roller table 4 to a pre-rolling train 5. After pre-rolling in the pre-rolling train 5, the preliminary material 3 passes uncut, i.e. as a strand, through a cutting up and delivery device 6, before the temperature of the preliminary material is set in a heating section 12 to rolling temperature. After the preliminary material has been treated in a de-blistering apparatus 13 which is disposed upstream from a finishing rolling train 14, the de-blistered preliminary material is rolled in a single- or multi-stand finishing rolling train 14. The finished rolled material is subsequently cooled down in a cooling section 15, cut off by shears 16 to a specific product length or a specific product weight and subsequently wound by a storage device 17 embodied as a winding device. The roller table 4 connects all parts of the installation between the horizontal strand guides of the continuous casting machine 2 and the storage device 17.
(8) The cutting up and delivery device 6 of FIG. 1 is shown in FIG. 2, comprising a first pair of shears 9a, a delivery device 8, a second pair of shears 9b, a lowerable roller table 18 and a raising device 11. Immediately after the occurrence of a fault in a part of the installation which is located downstream from the cutting up and delivery device 6 (e.g. the finishing rolling train 14 or the winding device 17) the preliminary material 3 is cut off by the second pair of shears 9b, which forms a strand portion 21 behind the second pair of shears 9b. In order to separate the strand portion 21 from the preliminary material 3 which is still being continuously produced emanating from the pre-rolling train 5, the strand portion 21 is raised by a raising device 11. The preliminary material 3 passing the second pair of shears 9b is divided up by the shears 9b into pieces of scrap 19 which are pushed via a lowerable roller table 18. Since the pieces of scrap 19 are generally difficult to recycle, after the occurrence of the fault, the preliminary material 3 is cut by first shears 9a into preliminary material portions 10, which each have a length of 8-14 m, wherein the preliminary material portions 10 are pushed via the delivery device 8 transverse to the transport direction 7 from the roller table 4. The disadvantage of the cutting up and delivery device 6 according to the prior art is that the length of the device 6 amounts to around 16 m, the preliminary material 3 is cooled down relatively significantly by the length in endless operation, because of the delay time of the preliminary material 3 in the device 6 a relatively strong blistering is formed, and the capital investment and operating costs of the cutting up and delivery device 6 as well as the continuous casting-rolling installation 1 are relatively high.
(9) FIGS. 3A and 3B show a first embodiment of the inventive cutting up and delivery device 6 which no longer exhibits the disadvantages of the solution according to FIG. 2. Apart from the shorter length of the device 6, the inventive device 6 can also be used with the known combined casting-rolling installation 1 of FIG. 1. In concrete terms the cutting up and delivery device 6 now merely has one pair of shears 9 which are embodied as pendulum shears or as drum shears. The shears 9 are followed in the transport direction 7 by two delivery devices 8, between which a raising device 11 is disposed in the transport direction. The raising device 11 is shown in FIG. 3A, 3B by a solid outline in the lowered position and by a dashed outline in the raised position. Disposed downstream of the rear delivery device 8 is a clamping device 23 which is embodied as a pair of “pinch rolls”) with which the strand portion 21 or the preliminary material 3 can be clamped. This prevents the strand portion 21 being moved against the transport direction 7 by the raising process. The clamping pushes the tail of the strand portion 21 in the transport direction 7 so that the preliminary material 3 coming after is at a sufficient distance from the strand portion 21.
(10) The method steps in the cutting up and delivery device 6 after the occurrence of a fault are shown in FIG. 4A . . . 4F. Shortly after or directly after the occurrence of a fault in a part of the installation which is disposed downstream from the cutting up and delivery device 6 the continuously produced preliminary material 3 coming from the preliminary rolling train 5 is cut off by the shears 9 which are embodied as pendulum shears (FIG. 4a shows the situation before the cut). A strand portion 21, which extends from the shears in the transport direction 7 is formed by the cutting-off. After the occurrence of the fault or before the raising of the strand portion 21 by the raising device 11, the strand portion is clamped by the clamping device 23, so that the tail of the strand portion 21 is not pulled by the raising against the transport direction 7 (FIG. 4B shows the situation directly before the clamping of the strand portion 21). In FIG. 4C the clamped strand portion 21 is lifted by the raising device 11 in a vertical direction, so that the strand portion 21 has a vertical offset to the following preliminary material 3 and the tail of the strand portion 21 is pulled away from the shears 9 in the transport direction 7 by the raising. Thus the tail of the strand portion 21 has a vertical and horizontal offset to the cutting plane of the shears 9. FIG. 4D shows that preliminary material 3 comes continuously from the preliminary rolling train 5, which is supported by the roller table 4. Since the head of the preliminary material 3 is at a specific distance (for example 10 m) from the shears 9, the shears 9 cut off a preliminary material portion 10 from the preliminary material 3. Directly after the cutting off the preliminary material portion 10 is accelerated in the transport direction by at least one driven roller 20, so that the preliminary material portion 10 is at a horizontal distance from the shears 9 (FIG. 4E shows the situation during acceleration). Finally the preliminary material portion 10 is pushed by the two delivery devices 8 before and after the raising device 11 out of the plane of the drawing, so that the roller table 4 is cleared between the two delivery devices 8. After the fault has been rectified, the strand portion 21 is removed for example by a crane 22.
(11) FIGS. 5A and 5B shows a second inventive embodiment of the cutting up and delivery device 6, which can likewise be used with the combined casting-rolling installation 1 in accordance with FIG. 1. It differs from the first embodiment in that a front raising device 11, a delivery device 8, a rear raising device 11, and the clamping device 23 are disposed downstream of the shears 9 in the transport direction. As in FIGS. 3A, 3B, a strand portion can be lifted by the two raising devices 11. The preliminary material 3 coming after is again cut off by the shears 9 into preliminary material portions 10 which can be pushed off by the push cylinder 25 of the delivery device 8 from the rollers 20 of the roller table 4 in the horizontal direction onto the support arms 29 of a stacking device 26.
(12) In the first and second embodiment of the invention a preliminary material portion 10, viewed in the outline from the delivery device 8 of the drawing, is pushed out. Naturally it would be just as easily possible to modify the delivery device 8 so that a preliminary material portion 10 is delivered into the plane of the drawing. An apparatus suitable for this purpose is known from WO 2009/121678 A1.
(13) Although the invention has been illustrated and described in greater detail on the basis of the preferred exemplary embodiments, the invention is not limited by the disclosed examples and other variations can be derived herefrom by the person skilled in the art without departing from the scope of protection of the invention.
LIST OF REFERENCE CHARACTERS
(14) 1 Continuous casting-rolling installation 2 Continuous casting machine 3 Preliminary material 4 Roller table 5 Preliminary rolling train 6 Cutting up and delivery device 7 Transport direction 8 Delivery device 9,9a,9b Shears 10 Preliminary material portion 11 Raising device 12 Heating section 13 De-blistering installation 14 Finishing rolling train 15 Cooling section 16 Shears 17 Storage device 18 Lowerable roller table 19 Scrap piece 20 Roller 21 Strand portion 22 Crane 23 Clamping device 24 Raising cylinder 25 Pushing cylinder 26 Stacking device 27 Raising bar 29 Support arm
