Method and system for the continuous descaling of broadband in a continuous pickling plant

Abstract

895,889. Making sheet-metal strip; reeling. THYSSEN-HUTTE A.G., AUGUST. Jan. 4, 1961 [Jan. 5, 1960], No. 380 / 61. Classes 83 (2) and 83 (4). In apparatus for continuous feeding of wide metal strip 63, Fig. 2, to a pickling bath (not shown), separate lengths supplied from large reels 42 of equivalent size required for subsequent cold-rolling mills are stitched into one continuous length by stamping tools 66 requiring minimum of delay and followed by a small looping pit 61. To reduce the delay time required in the looping pit the stitching devices 66 may be adapted to move forward with the strip. The large reels 42 are supplied from a multiplicity of preparation sections, Figs. 1a, 1b, sufficient in number to maintain production flow and in which the strip 9 from smaller hot strip coils 2 is passed through scale breaking and straightening rolls 21, 22, end cropping shears 27, 28, butt-welding apparatus 33 and flash-trimming tools 36 to form the reels 42 which are approximately three times the weight of small reels 2. Maintenance of supply of the intermediate reels 42 permits the output of strip from the pickling bath to be fed directly to a coldrolling mill without further reeling. Reeling.-The small reels 2 are supplied by conveyer 1 to an uncoiler 4, each coil 2 initially moving to the position 2<SP>1< / SP> where it is driven by supporting rolls 5 until the leading end 9 is separated by wedges 8 and reaches a driving roll pair 16. The wedges 8 are then withdrawn to the sides so that the coil is free to roll forward to the position 2<SP>11< / SP> on a lifting table 17 having loosely journalled rollers 19 and operated to raise the coil to a position at which it is supportably engaged by conical trunnions 14, Fig. 3, inserted from each side. The table is then free to be lowered in preparation for receiving the next reel.

Description

[0001] Method and system for the continuous descaling of broadband in a continuous pickling plant. The invention relates to systems for pickling broadband of the known type in which the broadband is continuously, i.e. endlessly, passed through the pickling bath.

[0002] In known systems, before it enters the pickling bath, the wide strip is unwound from a hot strip coil, pre-descaled, Endlessly welded or tacked. Hot-rolled strip refers here to the product of a wide strip hot rolling mill. After passing through The pickling bath causes the wide strip to be wound into a bundle whose weight is several times that of the hot-rolled strip bundle. Since for the Since welding the individual strips together takes a relatively long time, a loop pit is placed upstream of the pickling bath, in which such a A large supply can be stored so that the continuous pickling process does not need to be interrupted. A [material] lies in the loop pit. A multitude of loops stacked on top of each other. This has significant disadvantages: Firstly, due to the limited capacity of an already very The large loop pit only allows for a limited belt speed in the pickling bath. This makes the pickling plant difficult to utilize. Secondly, The looped band undergoes such sharp folds that it suffers significant structural deterioration at the bend points. Structural deterioration manifests as strip tearing during subsequent cold rolling of the pickled strip, which has extremely serious consequences. Due to the limited capacity of a loop pit, it is also sometimes necessary to temporarily reduce the belt speed in the pickling bath. to reduce the pickling process, which results in an uneven pickling outcome. The invention aims to provide a method and a means for carrying out the To create a suitable system that allows always using a single loop and therefore a relatively small loop pit. to get by, even though the pickling plant is operated at a substantially constant high belt speed.

[0003] The invention has in common with the known method that the strip unwound from the hot-rolled coils is mechanically pre-descaled, attached to the end of a belt passing through the pickling plant in front of a loop pit, after leaving the In the pickling plant, the stitching point of the strip is cut out, the strip is rewound and the strip bundle is fed to a cold rolling mill. The invention consists in combining two or more of the pre-descaled strips unwound from the hot-rolled coils into a single strip. are welded together and this strip is wound into an intermediate bundle before pickling; this intermediate bundle may need to be a fed to storage location or immediately unwound in an inlet section of the pickling plant and forwarded to the end of a line running in the pickling tanks The band is attached.

[0004] In the method according to the invention, the broadband is thus divided into two separate sections, namely a preparation section. and is treated in a pre-treatment section before entering the pickling bath. The slower processes therefore take place in a section where they do not cause any disturbance. This has an influence on the pickling speed. Therefore, separating the slow processes from the fast processes is the core idea of ​​the solution. of the existing problem.

[0005] The relatively long welding time has no harmful effect on a loop pit compared to the one according to the invention. different storage facilities, namely a stock of intermediate bundles ready for pickling, which are several times heavier than the Hot-rolled strip bundles. The intermediate strip storage requires a minimum of space, and the intermediate strips are not subject to any changes there. Furthermore, as many preparation lines supplying the same storage can be arranged upstream of the pickling plant as is necessary for a smooth operation. Operational management is required in each case. Furthermore, the existing concerning trend of using such high-performance broadband is countered. To construct hot rolling mills so that bundles of the finished weight of those to be supplied to the cold rolling mill can be rolled on them. Furthermore, permit the discontinuous Working preparation lines undergo thorough material inspection. Finally, the pickling plants can be utilized at their full capacity. This allows the belt speed to be kept constant, ensuring uniform pickling across the entire belt length.

[0006] A system suitable for carrying out the method according to the invention consists of a - preferably more than one - A preparation section and an entry section. Each preparation section essentially contains the familiar components such as scale breakers, Clipping shears, welding unit, and deburring machine. Likewise, the infeed section essentially consists of the familiar units such as... Stapler and loop pit.

[0007] The drawing schematically illustrates a system for carrying out the method according to the invention as an exemplary embodiment. Fig. 1 shows a preparation section of a pickling plant arranged in front of an intermediate stave storage area, Fig. 2 shows a preparation section arranged downstream of the intermediate stave storage area. Inlet section of the same pickling plant.

[0008] In a preparation section according to Fig. 1, the wide strip 2 unwound from a hot strip coil 1 passes through a unit 3 which It has a scale breaker and a set of straightening rollers. The pre-descaled and straightened strip passes through a separating shear 4 to cut off the front layer. and the rear roller head and for cutting out defective sections of the strip. This process involves a downtime of approximately 2 minutes, which is used for Material control may be further increased. Reference numeral 4 applies to a pair of cutting shears with an intermediate section. Welding machine 5 A trimming machine 6 is connected downstream, from which the strip is fed via a drive unit 7 to a winding machine 8. All units of the The preparation process briefly described in the composition is known, or its embodiment is not described by the present invention. recorded.

[0009] The winding machine 8 produces an intermediate bundle 9 of, for example, 18 t in weight, which consists of two hot-rolled strip bundles of 9 t each or of Three hot-rolled coils of 6 t each are formed. Some of these intermediate coils 9 supplied by the winding machine 8 lie in an indicated "Storage", i.e. on a transport device 10 ready for connection to the inlet section shown in Fig. 2.

[0010] In the inlet section according to Fig. 2, the transport device 10 is identical to the one shown in Fig. 1. Of the transport device 10 The intermediate bundle 9 is placed in a suitable manner into an unwinding machine 11. The resulting pre-descaled strip 12 is then placed in a Straightening machine 13, which is also a drive unit, is fed to a stapling machine 14, after the end 15 of the leading belt has already been there. was recorded. In the stapling machine 14, the front end 16 of the tape 12 and the rear end 15 of the tape in the pickling containers overlap. Leading band 17. The stapling machine of known type either staples using the spot welding method or presses staple-like shapes out of the band. Parts that, after appropriate bending, form-fit the ends together. After stapling, a drive mechanism 18, whose rollers the can avoid the thicker overlap point, the belt into a loop pit 19, from where it is carried via a further drive mechanism 20 to a non- The strip is fed into the pickling bath shown. The speed of the strip 17 entering the pickling bath is as high as the pickling plant allows, e.g. B. 150 m / min. The speed remains constant even when the rear end of the belt 15 is stationary for the purpose of stapling. Since the Since the stapling process is carried out very quickly, taking about 10 seconds, a relatively small webbing sling 21 is sufficient to minimize the standstill time. to overcome. The loop, thanks to suitable roller guides (not shown in the diagram), has no point where it would make a sharp bend. learns.

[0011] After exiting the pickling plant, the strip passes through a cutting shear in a known and therefore not shown manner, which is by An automatic control mechanism is activated when it passes the stapling point. The scissors cut out the stapling point from both the front and back. from the strip. The rear end of the cut, finished, pickled strip forms the end of the coil ready for the cold rolling mill. Using known devices, the front end of the next strip section is grasped and fed to a waiting winding machine.

[0012] It is not necessary that the preparation section according to Fig. 1 is arranged in the immediate vicinity of the inlet section according to Fig. 2, even though this is expedient for various reasons. Furthermore, it is not necessary that each inlet section according to Fig. 2 has a special The preparation section according to Fig. 1 is arranged upstream. For example, two pickling plants can be equipped with three preparation sections according to Fig. 1. In such a combination, the performance of the pickling plant can be increased by approximately 50 °1a compared to one based on the state of the art.

[0013] The components of the infeed section according to Fig. 2 are also known. For example, the stapling machine 14 is designated as such, unless there is no The spot welding machine is equipped with a stitcher. For thinner sheets under 1.5 mm thick, the spot welding machine is generally preferred. be and for thicker sheets the Stitcher.

Claims

[0014] PATENT CLAIMS:

1. Method for the continuous descaling of hot-rolled wide strips wound into bundles in a continuous pickling plant before cold rolling, in which the strip unwound from the hot strip coils is mechanically pre-descaled, to the end a belt passing through the pickling plant, attached in front of a loop pit, after leaving the pickling plant, the attachment point of the The strip is cut out, the strip is rewound and the strip bundle is fed to a cold rolling mill, characterized in that two or more of the pre-descaled strips unwound from the hot-rolled belts are welded together to form a single strip and This strip is wound into an intermediate bundle before pickling; this intermediate bundle may then be placed in a storage area or immediately in The material is unwound from an inlet section of the pickling plant and attached to the end of a belt running inside the pickling tanks.

2. Plant for carrying out the method according to claim 1, characterized in that it consists of a preparation section (Fig. 1) essentially with Tinder breaker (3), hair shears (4), Welding unit (5) and deburring machine (6) and from one of them a bearing (10) for intermediate bundles produced in the preparation section (9) separate infeed section (Fig. 2) essentially with stapling machine (14) and loop pit (19) and from one of them through the pickling bath separate shears that cut the endless strip (17) to the strip length required for the cold rolling mill by cutting out the stapling point (15 / 16). Bunden divides.

3. Plant according to claim 2, characterized in that the inlet section (Fig. 2) of the pickling bath has more than one preparation section. (Fig. 1) is prior. References: Willi Machu, Surface Pretreatment of Ferrous and Non-Ferrous Metals, 1954, p. 403 to 405 and 407.