ES2665174T3 - Combined pickling and laminating plant for stripping and laminating metal bands - Google Patents

Abstract

A combined pickling and rolling plant for stripping and rolling a metal strip, comprising - a pickling line for stripping the strip continuously; - storage means (20, 20 ') for storing the stripped strip, which are arranged downstream of the stripped line; - a reversible cold rolling train having at least two first rolling boxes (19), arranged downstream of said storage means (20, 20 '); - a first reel (21), which is arranged downstream of said at least two first rolling boxes (19), for winding the strip after a first rolling step; - at least a second reel (16), arranged upstream of said at least two first lamination boxes (19), for winding at least a portion of the strip after a second lamination stage in the opposite direction to the first stage, being said at least one second spool (16) being dimensioned to wind band portions up to a predetermined weight limit or a coil diameter limit; - a first cutting means, arranged between said at least a second reel (16) and said at least two first lamination boxes (19), which are adapted to cut the laminated strip each time a portion of strip wound on the al minus a second spool (16) reaches said predetermined weight limit or said predetermined diameter limit of the coil; characterized in that said storage means (20, 20 ') to store the stripped strip have a capacity of 500-3000 meters of strip length, said first reel (21) is dimensioned to wind a coil that weighs from 100 to 300 tons and / or having a diameter of up to 6 meters, - a welder (2 ') is arranged between said storage means (20, 20') and said at least two first rolling boxes (19), said at least one second spool (16) is arranged downstream of said welder (2), and because said welder (2 ') is adapted to weld a head of the laminated strip of output of the second rolling stage, obtained by a cut made by the first cutting means, with a band head coming from said storage means (20, 20 ').

Description

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DESCRIPTION

Combined pickling and laminating plant for stripping and laminating metal bands Field of the invention

[0001] The present invention relates to a combined pickling and laminating plant for stripping and laminating metal bands.

Prior art

[0002] The first fully continuous rolling mills in the cold rolling field emerged in the 70s and 80s, followed by the first combined pickling and rolling plants.

[0003] The benefit of laminating bands continuously using rolling welding joints has significant benefits in terms of plant productivity, with increases of 20% to 100% in productivity per hour or in rolled kilometers, in terms of surface quality, by reducing the risk of defect generation during the head feed and exit stage of the glues being laminated, and in terms of performance, by reducing head and tail material losses due to to the deviations of its thickness.

[0004] Such a solution involves providing plants in which continuous pickling is directly connected to a tandem cold rolling mill, with four or five rolling mills, which means higher investment costs and high production capacities, which generally exceed one million tons per year.

[0005] The drawback of such a solution is that, depending on the length of the product to be laminated each time, the production is limited to the "bottleneck" of the plant which, depending on the size and weight of the coil, may be the plant feed, pickling process, accumulations and rolling mill, in terms of the maximum speed that the tandem rolling mill can give with respect to the speed that can be obtained from each rolling box and the installed power .

[0006] The development of materials, especially of highly resistant steel, combined with the need for increasingly low thicknesses, has led to the development of new continuous rolling mills coupled to pickling lines. For example, a bent arrangement of the two floors has been made, so that the unwinding reel of the pickling line is located near the winding of the rolling mill. Thus, a reduction can be completed and the rolled coil can be fed to the pickling line inlet, to achieve a greater number of reductions in the rolling mill. This configuration has the associated drawback of a significant reduction in production capacity, because there is a need to provide several passes to finish a coil with the desired thickness.

[0007] An alternative applied by certain manufacturers has been to laminate the so-called "jumbo coils", which in some cases weigh more than 60 tons and are about 3 meters in diameter. This system, used in tandem batch rolling mills, asymptotically brings productivity closer to the value that can be obtained with a continuous train, improves their performance and, partially, the surface quality.

[0008] The advantage of this solution is a lower investment cost for the rolling mill, but it implies a significant cost of the coil handling structures, such as passageways and the corresponding overhead cranes, which must be distributed upstream and upstream under the plants to continuously support these higher loads.

[0009] An alternative to tandem cold rolling trains is that of reversible rolling mills, which are generally implemented for smaller production capacities, and more precisely:

- for reversible rolling mills of a single box, from 100,000 to 400,000 tons per year;

- for reversible double box rolling mills, from 200,000 to 1,000,000 tons per year. Due to its nature, rolling on reversible rolling mills implies a worse material performance compared to tandem rolling mills with several boxes, because the heads and rolling tails are not laminated, or only partially laminated . Additionally, the possibility of controlling the surface finish of the output belt is excluded in reversible rolling mills, which can be done in tandem rolling mills. This is because it is not advisable to replace the rolling box before carrying out the last pass, in order to transfer roughness to the surface of the web, and it is very complex and expensive to use a different emulsion system to reduce the surface dirt.

[0010] To improve the performance of reversible rolling mills, several procedures and innovations have been tested, such as:

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- develop equipment and a corresponding automation to obtain the feeding of the heads and the exit of the tails with closed boxes;

- implement spot welders to weld the bobbin head to an advance belt, that is, to a section of band that is not going to be laminated, to allow feeding and closing of the box on the material to be produced, as soon as as possible.

[0011] These techniques have generated partial results, because their application implies an obvious stiffening of the operating conditions of the rolling mill, and possible risks of damage to the rolling rollers.

[0012] US2012 / 0272703A1 describes an example of a combined pickling and laminating plant for metal bands, with reversible rolling mills.

[0013] Therefore, there is a need to provide a combined pickling and laminating plant, and a corresponding process, which allows to overcome the aforementioned drawbacks.

Summary of the invention

[0014] The main object of the present invention is to provide a combined cold-reversible pickling and lamination plant, which allows to obtain a quality, productivity and performance of the material comparable to those of a tandem rolling mill with four or five boxes, coupled to a continuous pickling, but with a lower investment cost.

[0015] Another object of the invention is to provide a plant that allows to obtain band coils with a specific weight of 15 to 21 kg / mm, which, therefore, are compatible with the usual coil handling structures.

[0016] Another object of the invention is to provide a plant in which the reversible lamination process is carried out, to allow control of the surface finish, required by the plates of the automobile and household appliances industries.

[0017] Therefore, the present invention proposes to achieve the above objects by providing a combined pickling and cold rolling plant of metal bands, which, according to claim 1, comprises

- a pickling line for stripping the band continuously;

- storage means for storing the pickling strip, which are arranged downstream of the pickling line;

- a reversible cold rolling mill having at least two first rolling boxes, arranged downstream of said storage means;

- a first reel, which is arranged downstream of said at least two first rolling boxes, for winding the web after a first rolling stage;

- at least a second reel, arranged upstream of said at least two first rolling boxes, for winding at least a portion of the web after a second rolling stage in the opposite direction to the first stage, said at least one second dimensioning spool for winding portions of band up to a predetermined limit weight or a bobbin limit diameter;

- first cutting means, arranged between said at least one second reel and said at least two first rolling boxes, which are adapted to cut the laminated strip each time a portion of the rolled band in the at least one second reel reaches said predetermined limit weight or said predetermined boundary diameter of the coil;

characterized by

said storage means have a capacity of 500-3000 meters of band length,

said first reel is sized to wind a coil weighing 100 to 300 tons and / or having a

diameter up to 6 meters,

- a welder is disposed between said storage means and said at least two first rolling boxes,

said at least a second reel is disposed downstream of said welder,

and because said welder is adapted to weld a head of the laminated strip of exit of the second stage of lamination, obtained by means of a cut made by the first cutting means, with a head of band coming from said storage means.

[0018] A second aspect of the present invention provides a cold pickling and laminating process for stripping and cold rolling a metal strip, which is carried out by means of the aforementioned plant, which, according to claim 10, comprises the following stages:

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a) continuously stripping the band by means of the pickling line;

b) store the stripped band continuously, with storage media that have a capacity of 500-3000 meters of band length;

c) carry out a first stage of lamination of a predetermined amount of belt, in the at least two first laminating boxes, and a successive winding on the first reel of a coil weighing 100 to 300 tons and / or with a diameter up to 6 meters;

d) carrying out a second rolling stage, in the opposite direction to the first stage, of said predetermined amount of strip in the at least two first rolling boxes, defining a rolled strip, and carrying out a winding of a first portion of rolled strip on at least a second reel, until a predetermined limit weight or boundary diameter of the coil is reached, thus defining a first laminated coil;

e) cutting the laminated strip, with the first cutting means, after the formation of said first rolled coil;

f) winding additional portions of the laminated web on said at least one second reel, until a predetermined boundary weight or boundary diameter of the reel is reached, defining additional laminated reels, carrying out a cutting of the laminated web, by means of the first cutting means, after the formation of each of said additional rolled coils;

g) welding, by means of the welder, a head of the laminated strip of exit of the second stage of lamination, obtained from the last cut made by said first cutting means, with a band head from said storage means;

h) repeat steps b) to g) while stage a) continues.

[0019] The invention allows a mega coil to be continuously laminated, in the first stage of lamination or in an odd stage of lamination, thus obtaining two or three thickness reductions.

[0020] A mega coil is a band coil that is obtained, for example, from at least 4-15 welds of smaller bands, with a weight of 100 to 300 tons and with a diameter of 4 to 6 m.

[0021] In a first variant of the invention, when the first winding reel, downstream of the rolling mill, reaches the predetermined maximum weight or maximum diameter, the band entering the rolling mill is cut, thus decoupling the laminating train of the pickling line. Preferably, the aforementioned mega coil is wound on the first reel after the first lamination stage.

[0022] The pickling line continues to process the web while storing it in the output storage media, of increased capacity (500-3000 m of band length, preferably at least 2000 m, which is equivalent to approximately 2-3 coils traditional whose size or weight is equal to approximately% of the size or weight of the mega coil). In this first variant of the invention, said increased capacity storage means consist of a horizontal tank comprising, at one end, at least one mobile carriage containing at least three crazy rollers and, at the opposite end, fixed crazy rollers , to define a winding path of the continuous stripping band. When moving, the mobile car can cause an increase in the stored band. The stripped strip is supported by suitable support rollers, and deflected by bypass rollers located at the opposite end of the mobile carriage.

[0023] At the same time, when reversing the rolling direction, the rolling mill carries out the second rolling pass with two or three thickness reductions. When the second winding reel, located upstream of the rolling mill, reaches the predetermined limit diameter or weight limit, the belt is cut and a first coil is discharged. This operation continues, thus producing, for example, four or five coils with a specific weight of 15 to 21 kg / mm (kg per mm of bandwidth). The sizes and / or weights of the final coils, on the second reel, are set at an automated level by establishing a limit weight and a limit diameter. The first of the two limits the coil reaches on a second reel will activate the cut, by means of the first cutting means.

[0024] At the end of this preparation activity of the final coils, the process begins again with the previously cut band head, and a new lamination stage or an odd stage is started.

[0025] In the first (odd) pass, a continuous rolling condition is created, by inserting a welder into the inlet of the rolling mill and leaving a tail ready, from the previous lamination, for welding with the aforementioned head.

[0026] In the second pass (pair) continuous lamination is also achieved for the second stage, by installing a double reel of reel or a reel carousel upstream of the laminating train, in cooperation with a cantilever scissor.

[0027] At the end of the second stage, the pickling line and the reversible rolling mill are coupled again, and continuous rolling from the first stage is resumed.

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[0028] A further advantage of the present invention lies in the fact that, by providing said storage means of increased capacity between the pickling line and the rolling train, and separating the two plants before the second rolling pass, they eliminate certain "bottlenecks" that limit the productivity of the traditional coupled plant, which allows for greater productivity.

[0029] In a second variant of the invention, instead, storage means of increased capacity are provided between the pickling line and the reversible rolling mill, comprising at least a third reel sized to wind a reel that weighs 100 to 300 tons and with a diameter of up to 6 meters (mega coil). Advantageously, two third integral reels can be provided with a rotating platform, adapted to rotate 180 ° around a vertical axis after a predetermined time, to wind a mega coil on one of the two third reels, so that, alternatively, a first third reel as a winding reel to wind the strip from the pickling line, and a second third reel is used as a unwinding reel to unwind the web, to feed the rolling mill. In this variant, the welder disposed between the pickling line and the first rolling mills only carries out operations prior to welding and welding operations, but does not cut the strip to decouple the rolling mill from the pickling line. In this case, decoupling is achieved through a second cutting means located upstream of the turntable, and by means of the turntable itself. The dependent claims describe preferred embodiments of the invention.

Brief description of the drawings

[0030] Other features and advantages of the invention will become more apparent from the detailed description of the preferred, but not exclusive, embodiments of a combined pickling and laminating plant, described by way of non-limiting example with the aid of the drawings. attachments, in which:

Fig. 1 represents a schematic view of a first embodiment of the plant, according to the invention. Fig. 2 represents an example of a rolling sequence for the first (odd) stage;

Fig. 3 represents an example of a rolling sequence for the second stage (pair), with a static cutting scissors;

Fig. 4 represents an example of a rolling sequence for the second stage (pair), with a cantilever scissors;

Fig. 5 represents a variant of the rolling mill of the plant of the invention.

Figs. 6a to 6d represent an example of the use of a welder, installed upstream of the rolling mill; Fig. 7 represents a schematic view of a second embodiment of the plant according to the invention; Fig. 8 represents a schematic view of a double system of winding and unrolling bands, for the pickling line exit and the entrance into the rolling mill.

Fig. 9 represents an operational sequence of the double winding and unwinding system mentioned above.

[0031] In the figures, the same numbers identify the same elements or components.

Detailed description of the preferred embodiments of the invention

[0032] With reference to Figures 1 to 9, preferred embodiments of a combined continuous pickling and reversible cold rolling plant are depicted.

[0033] In all its embodiments, the plant object of the present invention comprises:

- a pickling line, to strip the band continuously;

- means 20, 20 'of storage of increased capacity, for storing the stripped strip, which have a capacity of 500-3000 meters of band length and which are arranged downstream of the stripping line;

- a reversible cold rolling train having at least two first rolling boxes 19, disposed downstream of said storage means 20, 20 ’;

- a reel 21, which is arranged downstream of the first rolling boxes 19, for winding the web after a first rolling stage or an odd rolling stage, and advantageously sized to wind a coil weighing 100 to 300 tonnes and having a diameter of up to 6 meters;

- a 2 'welder, arranged between the means 20, 20' of storage and the first rolling boxes 19;

- at least one reel 16, arranged upstream of the first rolling boxes 19 and downstream of the welder 2 ', for winding at least a portion of the web after a second rolling stage or an even rolling stage, in the opposite direction to the first stage, said reel being advantageously sized at least one reel 16 for winding band portions to reach a predetermined boundary weight or bobbin diameter, for example a specific weight of 15 to 21 kg / mm or a diameter of approximately 20002100 mm ;

- first cutting means, for example a scissor 22, 23, arranged between said at least a second reel 16 and the first rolling boxes 19, which are adapted to cut the laminated strip each time

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that a portion of the web wound on the reel 16 reaches said predetermined boundary weight or bobbin diameter.

[0034] Advantageously, the welder 2 'is adapted to weld the head of the laminated strip of exit of the second stage of rolling, obtained from a cut made by the first cutting means, with a head of band coming from the 20, 20 'storage media.

[0035] The reel 21 has a greater capacity and is manufactured with a thicker tube, or with a round metal bar, capable of supporting the weight of large coils with a weight of up to 300 t, or with a diameter of up to 6 meters Such reel 21 is also sized to apply a dragging action of 350 to 500 kN, preferably 400 kN, during rolling, in order to facilitate greater thickness reductions in the rolling mill.

[0036] In a first embodiment of the invention, the welder 2 'is configured to cut the band from the storage means 20, after having subjected a predetermined amount of the band to the first rolling stage, thus decoupling the train from pickling line lamination. With reference to Figure 1 and Figure 6d, the pickling line comprises, in sequence:

- an inlet section with at least two unwinding reels 1 and a welder 2, preferably a laser welder capable of making rolling joints between the bands unwound by said reels 1, thus defining a continuous band;

- input storage means 3, for storing said continuous band and ensuring the continuous operation of the pickling process;

- a shelling machine 4 in which, by means of the combined action of dragging and alternating folding around rollers of a suitable diameter, the crushing of the oxide layer covering the continuous band is obtained, thus promoting the successive chemical attack;

- pickling tanks 5, for example from two to four according to the required productivity, in which the above-mentioned chemical attack on the continuous band occurs; said tanks 5 being provided with auxiliary systems for recirculating and heating the acid pickling solution.

[0037] Along the entire pickling line, belt guide systems, drag control systems, and various auxiliary systems are provided.

[0038] Optionally, downstream of pickling tanks 5 can be provided:

- intermediate storage means 6, in which the continuous pickling strip leaving the pickling tanks 5 is stored, after rinsing and drying it;

- a machine 7 for trimming the edges of the continuous strip pickling, said intermediate storage means 6 serving to avoid stops in the pickling process, in case of having to stop the cutting machine 7 to change the bandwidth or the blades .

[0039] Advantageously, in this first embodiment the plant of the invention is provided, directly downstream of the pickling tanks 5 or the cutting machine 7, of storage means 20 of increased capacity that act as storage means to the pickling line outlet, which are sized to receive 500 to 3000 meters of continuous strip pickling, preferably at least 2000 meters.

[0040] Said means 20 for storage of increased capacity consist of a horizontal tank comprising, at one end, at least one mobile carriage containing at least three crazy rollers and, at the opposite end, fixed crazy rollers, to define a winding path of the continuous stripped band. When moving, the mobile car can cause an increase in the stored band. Downstream of said increased capacity storage means 20 are provided, in sequence:

- a device 9 for controlling the drag and centering of the continuous stripped strip, sized to obtain a drag action of 250 to 500 kN, preferably 400 kN;

- said welder 2 ’, preferably a laser welder;

- said at least one reel 16, advantageously configured to wind band portions with a specific weight of 15 to 21 kg / mm, or reels with a diameter of up to 2000-2100 mm;

- a cutting scissors 22, 23;

- said at least two reversible first rolling boxes 19, of type four high or six high;

- reel 21, advantageously configured to wind a coil weighing 100 to 300 tons and with a diameter of up to 6 meters.

[0041] In an advantageous variant, there are only two first rolling boxes 19. Thus, two rolling stages are carried out with four thickness reductions in total.

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[0042] Along the rolling mill, auxiliary systems are provided for cooling and lubricating the web, and additional auxiliary systems for monitoring the rolling process.

[0043] The operation of this first embodiment of the invention (Figures 1 to 6d) is described below.

[0044] The unwinding reels 1 of the inlet section unwind respective bands that are welded together by means of the welder 2, thus defining a continuous band. To ensure the continuous operation of the pickling process, the continuous band is stored in the input storage medium 3. The continuous strip leaving the storage medium 3, still covered with a layer of oxide, crosses the shelling machine 4 in which, through the combined dragging and alternating folding action around rollers of a suitable diameter, spraying is obtained. of the oxide layer, thus promoting the successive chemical attack in the pickling tanks 5. Then the continuous band passes through the pickling tanks 5, and then it is rinsed and dried.

[0045] The continuous stripped strip enters the intermediate storage means 6, when they are supplied, and then crosses the edge cutting machine 7.

[0046] The continuous stripped strip then enters the storage means 20 of increased capacity, thus being stored by the crazy rollers in a meandering path of the continuous stripped strip, such as, for example, the one schematically illustrated in Fig. 1.

[0047] Next, the continuous stripping band passes through the traction and centering action control equipment 9, defining the rolling train entrance system, and passes through the welder 2 ’.

[0048] If a feed band 40 of approximately 30 meters in length is provided to the winding reel 21, it is advantageously possible to provide a seal 26 between said feed band 40 and the head 41 (Figure 6a) of the pickled continuous web, by means of a welder 2 ', thus obtaining the possibility of feeding this joint 26 through the reversible rolling train 19 of two boxes, with the strip stretched due to the winding reel 21 (figures 6a to 6d). The head 41 of the band is prepared for welding by precision cutting, using the 2 ’welder. Before welding, the end of the advance belt 40 is also prepared by making a precision cut, using the welder 2 ’.

[0049] During the first (odd) lamination stage, the first boxes 19 continuously laminate at least four bands, for example, welded together and that belong to said continuous band (with four welded joints, also taking into account that with the advance band), until forming the so-called mega coil on reel 21, which is a coil that weighs 100 to 300 tons and with a diameter of up to 6 meters. At this point, welder 2 ’cuts the joint between the fourth band and the fifth band, of the above-mentioned continuous band. As soon as the 300-ton limit weight or the 6-meter boundary diameter of the coil is reached, specific sensors send a control signal to the welder 2 ’that makes the aforementioned cut.

[0050] The number of welded starting bands that are required to form the aforementioned mega coil may vary, depending on the length of the starting bands.

[0051] During this first stage of rolling, the storage means 20 of increased capacity, which at the beginning of the rolling were almost at their maximum storage capacity, are emptied due to the difference in speed between the rolling mill and the line pickling

[0052] The tail of the continuous stripped strip, cut by the welder 2 ’, is fed to the winding reel 16 (Figure 3a) to start the second stage (pair) of reversible lamination, of the band wound on the reel 21.

[0053] When the reel 16 rolls a first laminated coil having a specific weight of 15 to 21 kg / mm or a diameter of 2000-2100 mm, the rolling mill stops, the specific sensors send a control signal to the static cutting scissors 22, which cuts the band that is being wound on reel 16, and the first laminated reel is discharged from reel 16. The band head obtained from this static cut, which comes out of the first boxes 19, is fed to the reel 16 and the second rolling stage is resumed, until a second laminated reel in the reel 16 having a specific weight of 15 to 21 kg / mm or a diameter of 2000-2100 mm. The rolling train stops again, the static cutting scissors 22 cuts the web that is being wound on the reel 16, and the second laminated reel is discharged from the reel 16. These operations are repeated until the second stage of rolling a last rolled coil, for example the fourth coil, when the feed belt, fixed to the reel 21, is about to enter the first rolling boxes 19. The lamination is stopped, the first boxes 19 are opened, the static cutting scissors 22 cuts the band again and said last rolled reel is discharged from the reel 16, which has a specific weight of 15 to 21 kg / mm or a diameter of 2000 -2100 mm, while the head of the advance belt reaches the welder 2 'to make a weld joint that can be laminated with the head of the continuous stripped band, previously cut by the welder 2'. Once this welding is completed, the cycle begins again with a first (odd) stage of lamination and the formation of

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a new mega coil on spool 21. When the welder 2 'is inserted into the laminating train inlet, and leaving a band tail of the previous lamination ready, for welding with the head of the continuous strip stripped, previously cut by the welder 2 ', a continuous rolling condition is created in the first odd stage of lamination.

[0054] During the rolling stage, the storage means 20 of increased capacity are filled with the continuous stripped strip leaving the pickling line. Advantageously, the speed of the pickling line is adjusted so as to substantially equalize the time to completely fill the storage means 20 and the cycle time of the rolling train, to complete the formation of the rolled coils mentioned above in the reel 16.

[0055] To obtain a continuous rolling condition also in the second lamination stage, or even stage, a variant allows the use of a cantilever shear 23 instead of the static shear 22, and a double reel or a reel carousel 24, instead of the single reel 16 (figure 4). The cantilever cutting scissors 23 is adapted to cut the laminated web at a speed of 50 to 500 mpm. The carousel 24 generally has two reels 16, which are diametrically opposed to each other and are articulated in a rotating drum, which alternately rolls up the laminated web: when one of the reels is winding a final coil, the other reel of the final coil is released. pre-rolled

[0056] In a second embodiment of the invention, illustrated in Figures 7 to 9, the storage means 20 'of increased capacity instead comprise at least one other reel 28 of increased capacity, sized to wind a coil weighing 100 to 100 300 tons and have a diameter of up to 6 meters (mega coil). Advantageously, two reels 28, 28 'of integral capacity are provided integral to the opposite ends or sides of a rotating platform 27 (Figure 8), adapted to rotate 180 ° around a vertical axis after a predetermined time in which a mega coil on one of the two reels 28, 28 ', so that a first reel 28 is used alternatively as a reel to wind the continuous stripped strip, from the pickling line, and a second reel 28' is used as the reel unwind the continuous stripped strip that feeds the rolling mill. Second cutting means are provided, for example an additional scissor (not illustrated), arranged upstream of the turntable 27 and configured to cut the stripped band once the mega coil has been wound on one of the two reels 28, 28 '. Also in this case, specific sensors send a control signal to the second cutting means, once the 300-ton weight limit or the 6-meter coil boundary diameter is reached. After this cut, the rotating platform 27 is rotated 180 °.

[0057] A winding path 8 (Figure 7) of the continuous pickling strip can be provided, upstream of said second cutting means, by means of crazy rollers 8 ', whose object is to store the strip processed by the pickling line each once the reel 28 of increased capacity stops. Upstream of said coil path 8, the same components of the plant of fig. 1, that is, all the components indicated with the numbers 1,2, 3, 4, 5, 6 and 7.

[0058] The turntable 27, which defines a dual system for winding / unwinding the web, can be operated by means of a rack system, for example. Its rotation is controlled by an electric or hydraulic motor 32, which allows a 180 ° rotation to be obtained. On the opposite sides of said turntable 27 a respective reel 28, 28 ’of increased capacity is mounted, adapted to wind / unwind mega coils weighing 100 to 300 t and with a diameter of approximately 6 meters.

[0059] The knobs 31,30 and 31 ', 30' of rotation of the respective reels 28, 28 'are independent of each other, to independently control the winding rotation of the strip from the pickling line, and the rotation of unwind of the stripped strip, towards the first rolling mill boxes 19 of the reversible cold rolling mill.

[0060] During the 180 ° rotation of the rotating platform 27, the rotational controls 31, 30 and 31 ', 30' are decoupled from the respective reels 28, 28 'through a respective movable joint 29, 29', It retracts.

[0061] The band wound and unwound from the reels 28, 28 'is kept aligned and centered by an axial movement of a respective mandrel 34, 34', controlled by a corresponding hydraulic cylinder 33, 33 '.

[0062] Downstream of the reels 28, 28 ', and therefore of the turntable 27, are provided in sequence (Figure 7):

- a 2 ’welder, preferably a laser welder;

- at least one reel 16, advantageously configured to wind band portions with a specific weight of 15 to 21 kg / mm or coils with a diameter of up to 2000-2100 mm;

- cutting scissors 22;

- said at least two first boxes 19 of reversible lamination, of type four high or six high;

- the reel 21 of increased capacity, advantageously configured to wind a coil weighing 100 to

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300 tons and with a diameter of up to 6 meters.

[0063] In an advantageous variant, there are only two first rolling boxes 19. Thus, two rolling stages are carried out with four thickness reductions in total.

[0064] Along the rolling mill, auxiliary systems are provided for cooling and lubricating the web, and additional auxiliary systems for monitoring the rolling process.

[0065] The operation of this second embodiment of the invention (Figures 7 to 9) is described below.

[0066] The unwinding reels 1 of the inlet section unwind respective bands that are welded together by means of the welder 2, thus defining a continuous band. To ensure the continuous operation of the pickling process, the continuous band is stored in the input storage medium 3. The continuous strip leaving the storage medium 3, still covered with a layer of oxide, crosses the shelling machine 4 in which, through the combined dragging and alternating folding action around rollers of a suitable diameter, spraying is obtained. of the oxide layer, thus promoting the successive chemical attack in the pickling tanks 5. Then the continuous band passes through the pickling tanks 5, and then it is rinsed and dried.

[0067] The continuous stripped strip enters the intermediate storage means 6, when they are supplied, and then crosses the edge cutting machine 7.

[0068] The pickled continuous web then enters the storage means 20 'of increased capacity, by winding, for example, in the reel 28' of increased capacity of the rotating platform 27 (Figure 8).

[0069] Fig. 9 schematically depicts the operating sequence at the speed of the turntable 27. In a first stage (fig. 9a), the first reel 28 begins to wind a mega coil of pickled band, while the second reel 28 'begins to unwind another mega coil, previously wound, towards the first rolling boxes 19 to begin the first rolling stage.

[0070] In a second stage (fig. 9b), while the reversible rolling mill carries out the second rolling stage and the second reel 28 'is emptied, the first reel 28 completes the winding of the pickled band mega coil. , the winding is interrupted, the stripped strip is cut upstream of the rotating platform 27 by means of the second cutting means, and the rotating platform 27 begins to rotate to place said first reel 28 in position, to unwind the stripped strip towards the first 19 lamination boxes.

[0071] In a third stage (fig. 9c), with the first reel 28 in the unwind position, the band is unwound from the first reel 28 and brought to the feeding or welding position, near the welder 2 ' , while the second reel 28 'begins to wind a new mega pickled band coil.

[0072] The band head is prepared, unwound from a new mega coil on reel 28 or reel 28 ', making a precision cut with welder 2' so that it is ready for successive welding.

[0073] Assuming that an advance band of approximately 30 meters in length has been left on the winding reel 21, by means of the welder 2 'it is advantageously possible to make a joint between the advance band and the head of the stripped band, from the first reel 28, thus achieving the possibility of feeding said joint through the reversible rolling train with two first boxes 19, with the strip stretched due to the reel 21 of exit winding.

[0074] Before welding, the end of the feed belt is also prepared by making a precision cut with the welder 2 ’.

[0075] During the first (odd) lamination stage, the first boxes 19 continuously laminate the unwound web from the first reel 28, until the so-called mega coil is again achieved in the reel 21 of increased capacity.

[0076] During this first stage of rolling, the mega coil is completely unwound in the reel 28 of unwounding of increased capacity, at the same time as the other reel 28 ', in the winding position of the stripped strip, rolls a new mega coil

[0077] The spool of the continuous strip pickled, rolled and unwound on the spool 21 is fed to the winding reel 16, thus initiating the second stage (pair) of reversible lamination (fig. 7).

[0078] When the reel 16 rolls a first laminated coil having a specific weight of 15 to 21 kg / mm or a diameter of 2000-2100 mm, the rolling mill stops, specific sensors send a control signal to the static cutting scissors 22, which cuts the band that is being wound on reel 16, and is discharged from the

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Reel 16 the first rolled coil. The band head obtained is fed to the reel 16, which leaves from the first rolling boxes 19, and the second rolling stage is resumed until a second coil rolled in the reel 16 is obtained, with a specific weight of 15 to 21 kg / mm or with a diameter of 2000-2100 mm. The rolling mill is stopped again, the static cutting scissor 22 cuts the web that is being wound on the reel 16, and the second laminated reel is discharged from the reel 16. These operations are repeated until the second stage of lamination of a last rolled coil, for example the fourth coil, when the advance belt is about to enter the first rolling boxes 19. The lamination is stopped, the first lamination boxes 19 are opened, the static cutting scissors 22 cuts the band again, and said last laminated reel having a specific weight of 15 to 21 kg / mm or a diameter is discharged from the reel 16 2000-2100 mm.

[0079] At the same time, as soon as the winding of a mega coil in the reel 28 'of increased capacity winding is completed, the winding is interrupted, the stripped strip is cut upstream of the rotating platform 27, by means of the second cutting means, and said rotating platform 27 rotates 180 °, thus bringing the reel 28 'to the unwind position towards the reversible rolling mill, and the reel 28 to the winding position of the web from the line of pickling

[0080] The band head, unwound from the new mega coil on the reel 28 ', is fed in a known manner until it reaches the welder 2', and is prepared by making a precision cut with the welder 2 'so that it remains ready for successive welding. Before welding, the end of the feed belt is also prepared by making a precision cut with the same 2 ’welder.

[0081] Once this welding is completed between the feed belt and the head of the band of the new mega coil, the cycle begins again with a first (odd) lamination stage and the successive formation of the mega coil in the reel 21. By inserting the welder 2 'into the inlet of the rolling mill and leaving a band tail of the previous lamination ready, for welding with the head of the successive continuous stripped strip, a continuous rolling condition is created in the first stage or odd stage of lamination.

[0082] In order to obtain a condition of continuous lamination also in the second stage or even stage of lamination, a variant makes use of a scissors 23 of cantilever cutting instead of the scissors 22 of static cutting, and of a double reel or a carousel 24 reels instead of single reel 16 (similar to Figure 4). The cantilever cutting scissors 23 is adapted to cut the laminated web at a speed of 50 to 500 mpm. The carousel 24 generally has two reels 16, which are diametrically opposed to each other and are articulated in a rotating drum, which alternately rolls up the laminated web: when one of the reels is winding a final coil, the other reel is released from the final coil pre-rolled

[0083] In both embodiments described above, it is possible to provide an additional rolling box 25 disposed upstream of the at least two first rolling boxes 19, and configured to open in the odd rolling stage and close in the even rolling stage . Thus, two rolling stages are carried out with five thickness reductions in total.

[0084] Advantageously, the additional rolling box 25 is provided with operating rollers having a surface roughness greater than the surface roughness of the operating rollers of the first two rolling boxes 19. This variant allows to obtain a lamination surface with controlled roughness, in the last stage of lamination. Preferably, the rolling box 25 will be cooled in the second and last rolling stage, with a dedicated system, to obtain a better surface cleaning.

Claims (15)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 1. A combined pickling and laminating plant for stripping and laminating a metal strip, comprising - a pickling line for stripping the band continuously; - storage means (20, 20 ’) for storing the pickling strip, which are arranged downstream of the pickling line; - a reversible cold rolling train having at least two first rolling boxes (19), arranged downstream of said storage means (20, 20 ’); - a first reel (21), which is arranged downstream of said at least two first rolling boxes (19), to wind the web after a first rolling stage; - at least a second reel (16), arranged upstream of said at least two first rolling boxes (19), for winding at least a portion of the web after a second rolling stage in the opposite direction to the first stage, being said dimensioning said at least a second reel (16) for winding portions of band up to a predetermined limit weight or a bobbin limit diameter; - first cutting means, arranged between said at least a second reel (16) and said at least two first rolling boxes (19), which are adapted to cut the laminated strip each time a portion of the rolled band in the at less a second reel (16) reaches said predetermined weight limit or said bobbin limit diameter; characterized by said storage means (20, 20 ’) for storing the stripped band have a capacity of 500-3000 meters of band length, said first reel (21) is sized to wind a coil weighing 100 to 300 tons and / or having a diameter of up to 6 meters, - a welder (2 ’) is disposed between said storage means (20, 20’) and said at least two first rolling boxes (19), said at least a second reel (16) is disposed downstream of said welder (2), and because said welder (2 ') is adapted to weld a head of the laminated strip of exit of the second stage of rolling, obtained by means of a cut made by the first cutting means, with a band head coming from said means ( 20, 20 ') storage. 2. A plant according to claim 1, wherein the welder (2 ') is configured to cut the web from the storage means (20) once a predetermined amount of the web has been subjected to the first lamination stage, decoupling the laminating train from the pickling line. 3. A plant according to claim 1, wherein said storage means (20 ') comprise at least a third reel (28) sized to wind a coil weighing 100 to 300 tons and / or having a diameter up to 6 meters. 4. A plant according to claim 3, wherein two integral third reels (28, 28 ') are provided at opposite ends of a rotating platform (27), adapted to rotate about a vertical axis, so that alternatively use a first third reel (28) as a reel to wind the strip from the pickling line, and use a second third reel (28 ') as a reel to unwind the belt that feeds the rolling mill. 5. A plant according to claim 4, wherein second cutting means provided upstream of said turntable (27) are provided, configured to cut the stripped strip once the coil has been wound, weighing from 100 to 300 tons and / or has a diameter of up to 6 meters, in one of the two third reels (28, 28 '). A plant according to any one of the preceding claims, wherein at least one additional rolling box (25) provided upstream of the at least two first rolling boxes (19) is provided, and configured to open in the first stage of lamination and closing in the second stage of lamination, said additional lamination box (25) being equipped with operating rollers having a surface roughness greater than the surface roughness of the operating rollers of the first two boxes (19) of lamination. 7. A plant according to any one of the preceding claims, wherein a feed belt (40) fixed to said first reel (21) is provided, so that the welder (2 ') is also adapted for welding, before the first lamination stage, the advance belt (40) to a first band head (41) from said storage means (20, 20 '). 5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 8. A plant according to any one of the preceding claims, wherein the first cutting means is a static cutting scissors (22) or a cantilever cutting scissors (23). 9. A plant according to claim 8, wherein, in the case of the cantilever cutting scissors, a second double reel (16) or a carousel (24) of second reels (16) is provided for carrying out An even stage of continuous lamination. 10. A pickling and laminating process for stripping and laminating a metal strip, by means of a plant according to claim 1, comprising the following steps: a) continuously stripping the band by means of the pickling line; b) store the stripped band with the storage media (20, 20 ’), which have a capacity of 500-3000 meters of band length; c) carry out a first stage of lamination of a predetermined amount of strip, in the at least two first boxes (19) of lamination, and a successive rolled on the first reel (21) of a reel weighing 100 to 300 tons and / or with a diameter of up to 6 meters; d) carrying out a second rolling stage, in the opposite direction to the first stage, of said predetermined amount of strip in the at least two first rolling boxes (19), defining a rolled strip, and carrying out a winding of a first portion of laminated web on at least a second reel (16), until a predetermined boundary weight or boundary diameter of the coil is reached, thus defining a first rolled bobbin; e) cutting the laminated strip, with the first cutting means, after the formation of said first laminated coil; f) winding additional portions of the laminated web on said at least one second reel (16), until a predetermined boundary weight or boundary diameter of the reel is reached, defining additional laminated reels, carrying out a cutting of the laminated web, by means of of the first cutting means, after the formation of each of said additional rolled coils; g) welding, by means of the welder (2 '), a head of the laminated strip of exit of the second stage of rolling, obtained from the last cut made by said first cutting means, with a band head coming from said storage means (20, 20 '); h) repeat steps b) to g) while stage a) continues. 11. A process according to claim 10, wherein between stage c) and stage d) a strip of the stripped strip is provided by means of the welder (2 '), to decouple the rolling mill from the line pickling 12. A process according to claim 11, wherein the speed of the pickling line is adjusted to equalize the time it takes to completely fill the storage means (20) and the time that the rolling mill cycle it takes to complete the formation of the rolled coils, in said at least a second reel (16). 13. A process according to claim 10, wherein, once a coil having a weight of 100 to 300 tons and / or having a diameter of up to 6 meters in said storage means (20 ') has been wound, comprising two third reels (28, 28 ') integral at opposite ends of a rotating platform (27), a cut of the band is made upstream of said rotating platform (27). 14. A process according to claim 13, wherein, after winding a first coil weighing 100 to 300 tons and / or having a diameter of up to 6 meters in a spool (28 '), of said two third parties reels (28, 28 '), the turntable (27) rotates 180 °, so that the other reel (28) of said two third reels (28, 28') is used as a reel to wind the band, to form a second coil that weighs 100 to 300 tons and / or has a diameter of up to 6 meters, while the reel (28 ') will be used as a reel to unwind the first coil to feed the rolling mill, and so on. 15. A process according to any of claims 10 to 14, wherein a feed belt (40) is provided, fixed on the first reel (21) to produce, before the first stage c), by means of the welder (2 '), a welding joint between said feed band (40) and a first head (41) of the stripped strip, which reaches the rolling mill; and in which, before step g), when said advance belt is about to enter the rolling mill, at least two rolling boxes (19) are opened and the welder (2 ') is approached head of the laminated strip, obtained from the last cut made by the first cutting means.