EP3453466B1 - Rolling mill for rolling a metallic product and method for operating a rolling mill - Google Patents

Description

The invention relates to a rolling train for rolling a metallic material, comprising a cooling device for cooling the rolls of a rolling stand and / or the material to be rolled or rolled. The invention also relates to a method for operating a rolling train with such a cooling device.

In the operation of rolling mills, the work rolls are typically cooled during the rolling operation. Various types of roller cooling devices are available for this in the prior art (for example spray cooling, shell cooling, high-turbulent cooling, roller cooling with water curtains, ultra-high pressure cooling and roller cooling with laminar tubes). It is always provided that a cooling concept for cooling the rolls is selected and then implemented in a rolling train.

A rebuilding of a roller cooling system is seldom encountered and is always associated with a relatively high effort and possibly with a risk; Furthermore, a conversion time is required for such a conversion during which the system is not available and thus causes a loss of production. This is particularly true if the cooling principle is fundamentally changed, i.e. if, for example, a changeover from high pressure to low pressure or another structural solution is to be used.

Spray cooling is often used as the roller cooling device, in which a large number of water jets emerge from nozzles from one or more distributor pipes under a pressure of approx. 5 to 25 bar. The water jets hit the work roll at different angles in the radial direction and cool it. For this purpose, the DE 101 31 369 A1 Referenced. Other similar solutions show the EP 1 044 724 A2 , the WO 2013/167642 A1 and the DE 200 06 508 U1 The preamble of claim 1 is based on EP 1044724 A2 .

In order to increase the cooling efficiency or to operate the roller cooling with lower water pressure and thus lower energy consumption, shell cooling systems are also known, as they are, for example, in FIG EP 2 846 940 B1 are described. Here, water or another cooling medium is guided between the work roll and a shell in a relatively narrow gap along the work roll and the work roll is thus cooled efficiently and mostly at low operating pressure.

The invention is based on the object of developing a rolling train of the generic type in such a way that it is possible in a simple manner to adapt the cooling to different desired cooling conditions. Furthermore, a corresponding method is to be proposed for this. In particular, the disadvantages described above when switching from one cooling concept to another are to be avoided.

The solution to this problem by the invention is characterized in that the cooling device comprises at least one support frame for at least one cooling element, the support frame being equipped with at least one receiving element for receiving a cooling element, the cooling device comprising at least two cooling elements of different designs and on the receiving element alternatively, a cooling element of a selected type is added.

Two cooling elements of different designs are thus available in order to be able to alternatively receive a cooling element of a selected design on the receiving element.

The cooling element of one type can be a spray bar for spraying cooling medium onto the roller and / or onto the material to be rolled. The cooling element of a (different) design can be at least one cooling nozzle with a cooling shell for applying cooling medium to the roller.

Other alternative cooling elements of a special design can be high-turbulent cooling, roller cooling with a water curtain, ultra-high pressure cooling or roller cooling with laminar tubes.

It is particularly preferred that the receiving element of the supporting frame has a mechanical interface that is designed for mechanical connection to an adapter that is arranged on the cooling element, the adapters of all cooling elements being designed to match the mechanical interface of the receiving element.

The receiving element of the supporting frame can furthermore have a fluidic interface which is designed for fluidic connection to the cooling element.

At least one supply line for cooling medium is preferably arranged in the supporting frame, the supply line having means for adjusting the pressure of the cooling medium and / or the cooling medium volume flow. In this way, a process-technically optimal adaptation of a selected cooling concept can take place in a simple manner, in which the pressure of the cooling medium or its volume flow is optimally adjusted.

1. a) Betreiben der Walzstraße unter Verwendung mindestens eines Kühlelements einer ersten Bauart, wobei über das Kühlelement Kühlmedium mit einem ersten Druckniveau und/oder mit einem ersten Volumenstrom ausgebracht wird;
2. b) Demontage des mindestens einen Kühlelements der ersten Bauart;
3. c) Montage mindestens eines Kühlelements einer zweiten Bauart;
4. d) Betreiben der Walzstraße unter Verwendung mindestens eines Kühlelements der zweiten Bauart, wobei über das Kühlelement Kühlmedium mit einem zweiten Druckniveau und/oder mit einem zweiten Volumenstrom ausgebracht wird, der sich vom ersten Druckniveau und/oder vom ersten Volumenstrom unterscheidet.

The proposed method for operating a rolling train with a cooling device of the type mentioned above comprises the steps:

1. a) operating the rolling train using at least one cooling element of a first type, cooling medium being discharged via the cooling element with a first pressure level and / or with a first volume flow;
2. b) dismantling the at least one cooling element of the first type;
3. c) assembly of at least one cooling element of a second type;
4. d) Operating the rolling train using at least one cooling element of the second type, with cooling medium being discharged via the cooling element with a second pressure level and / or with a second volume flow that differs from the first pressure level and / or from the first volume flow.

It is preferably provided that a first cooling element is operated with a supply pressure between 3 bar and 30 bar, preferably between 7 bar and 15 bar, and that a second cooling element is operated with a supply pressure of less than 6 bar, preferably with a supply pressure between 1 bar and 5 bar.

A second cooling element can be operated by a high pressure media supply via a pressure reducing element (in this case, the media supply does not need to be converted from high pressure to low pressure). However, it can also be provided that, after a corresponding conversion of the media supply without a pressure reduction stage, said cooling element is operated by a low-pressure media supply.

According to the above proposal, an improvement and optimization of the work roll cooling is thus possible through the aforementioned conversion concept for a changeover of the cooling.

In order to enable a smooth and risk-free conversion or to minimize the conversion time and thus the loss of production of the rolling mill, the above-mentioned device and the explained method are proposed, which enable a simple conversion of work roll cooling methods and devices. As a result, the mechanical conversion effort can also be kept small and at least a simple dismantling or alternative operation two different roller cooling devices. This also makes it possible in particular to be able to test different cooling systems in a simple manner before the one that has proven to be best for the specific application is selected.

When converting a roller cooling system, it makes sense to proceed in steps in order to minimize the risk. Furthermore, the user would like to have the security of being able to easily dismantle the roller cooling in the event of problems. These requirements are met in a very advantageous manner by the proposed solution.

Fig. 1

schematisch eine Kühlvorrichtung zum Kühlen der Arbeitswalzen eines Walzgerüst, wobei ein Kühlelement einer ersten Bauart in Form eines Sprühbalkens eingesetzt wird,

Fig. 2

schematisch die Kühlvorrichtung gemäß Figur 1, wobei nunmehr ein Kühlelement einer zweiten Bauart in Form von Kühldüsen mit einer Kühlschale zum Aufbringen von Kühlmedium auf die Walze eingesetzt wird,

Fig. 3

schematisch die Versorgung der Kühlvorrichtung mit Kühlmedium bei einer Betriebsweise gemäß Figur 1,

Fig. 4

schematisch die Versorgung der Kühlvorrichtung mit Kühlmedium bei einer Betriebsweise gemäß Figur 2 und

Fig. 5

schematisch eine Variation der Lösung gemäß Figur 4.

Exemplary embodiments of the invention are shown in the drawing. Show it:

Fig. 1

schematically, a cooling device for cooling the work rolls of a rolling stand, wherein a cooling element of a first type in the form of a spray bar is used,

Fig. 2

schematically the cooling device according to Figure 1 , now a cooling element of a second type in the form of cooling nozzles with a cooling shell is used to apply cooling medium to the roller,

Fig. 3

schematically the supply of the cooling device with cooling medium in an operating mode according to FIG Figure 1 ,

Fig. 4

schematically the supply of the cooling device with cooling medium in an operating mode according to FIG Figure 2 and

Fig. 5

schematically a variation of the solution according to Figure 4 .

In Figure 1 and Figure 2 a cooling device 1 can be seen with which the work rolls 2 of a rolling stand are cooled. The cooling device 1 has a support frame 3 in which two cooling elements 4 'or 4 "of a certain type are mounted, namely one for cooling the upper work roll 2 and one for cooling the lower work roll 2. The support frame 3 is in one piece in the exemplary embodiment The supporting frame can of course alternatively also be designed as a multi-part structure (especially since upper and lower cooling elements are usually provided).

In Figure 1 a cooling element 4 'of a first type is used, namely in the form of a spray bar. In Figure 2 a cooling element 4 ″ of a second design different from the first type is used, namely in the form of cooling nozzles with a cooling shell for applying cooling medium to the roller 2.

The support frame 3 is equipped with receiving elements 5 (an upper one for the upper cooling element and a lower one for the lower cooling element). The receiving elements 5 are designed in such a way that they can alternatively receive a cooling element 4 'or 4 ", that is to say alternatively either a cooling element of a first type or a cooling element of a second type. The receiving elements 5 could also be used as mechanical holders for one cooling element 4 each ', 4 ".

Adapters 7, which are used to mechanically fix the cooling element 4 ', 4 "on the receiving element 5, are arranged on all cooling elements 4 ′, 4 ″.

The conception provides that the receiving element 5 and the adapter 7 define a mechanical interface 6, which is designed according to the standard or standardized such that optionally different cooling elements 4 ′, 4 ″ can be mechanically fastened to the day frame 3 via the receiving element 5.

In an analogous manner there is also a fluidic interface 8 via which a cooling element 4 ', 4 "can be supplied with cooling medium. Here, too, there is a standard or standardized connection so that the cooling elements 4', 4" can be exchanged without any problems .

In the Figures 1 and 2 is illustrated with the dimensions a, b and c for the upper mechanical interface 6 and with the dimensions X, Y and Z for the lower mechanical interface 6 that a precise and easy positioning of a cooling element 4 ', 4 "on the receiving element 5 is possible The same applies to the connection of a cooling element 4 ', 4 "to the fluidic interface 8, although no corresponding dimensions are entered in the figures.

The easy adaptation of the respectively mounted cooling elements 4 ', 4 "to a process-technically optimal cooling medium supply is in the Figures 3 to 5 illustrates where a supply line 9 for cooling medium can be seen, with which the cooling elements 4 'or 4 "are supplied with it. Means 10 and 10' for adjusting the pressure or the volume flow of the cooling medium are provided here The fact that different types of cooling elements also require different pressures or volume flows in order to be able to work efficiently and economically.

Correspondingly for the first roller cooling device Figure 1 it is therefore a cooling system in the form of spray bars which carry a large number of spray nozzles from which a cooling medium is sprayed against the work roll 2 (spray cooling). The second, alternative roller cooling device is shown in FIG Figure 2 a cooling element in the form of cooling nozzles with cooling shells is provided, in which the same cooling medium is guided along the circumference of the work roll 2 against the direction of rotation of the work roll (shell cooling). A possible actuating mechanism for pivoting the shell cooling unit is for the purpose of simplification in Figure 2 not shown.

For the advantageous conversion of the work roll cooling systems, the different work roll cooling devices for the top and / or bottom roll are designed in such a way that they can both be alternatively received or fastened in the support frame (support structure 3).

Thus, for example, a spray cooling system can be installed in this support frame (support structure 3) or - alternatively - a shell cooling system for cooling the upper and / or lower roller can be attached in the same support frame. The support frame is advantageously designed in such a way that fastening points (receiving elements 5) are provided which can optionally receive both roller cooling devices.

The fastening points for the two different roller cooling devices can be provided at the same position on the support frame (as indicated with the dimensions a, b, c or X, Y and Z) or at different positions.

When changing or converting from a first to a second roller cooling device, the supporting frame 3 and the strippers 11, 12 and also the displacement cylinder 13 for the supporting frame 3 (supporting frame) remain functionally and structurally unchanged. Different connecting links or adapter links can be used between the different cooling devices and the support frame. The two roller cooling systems are connected to the media supply with hose connections in order to be able to adapt to different cooling beam geometries and feed angles and to be able to compensate for a displacement of the support frame together with the respectively built-in roller cooling devices.

In the Figures 1 or 2 are still the coolant supply 14, the fastening screws 15, the cylinder / support frame 16 stop point and the track 17 for the supporting frame 3, the spray nozzles 18, the cooling shell 19, the nozzle 20, the joint 21 for the cooling shell, the articulation lever 22 and the articulation 23 for the articulation lever are marked, likewise the rolling direction W.

Figure 3 and Figure 4 show a high pressure media supply 24, Figure 5 a low pressure media supply 25. In the case of the Figure 3 there is a roller cooling device with spray cooling, while in the case of Figures 4 and 5 a roller cooling device with shell cooling is present.

According to Figure 3 the high operating pressure is regulated by the means 10 in the form of a control or on / off valve. With the solution according to Figure 4 a low operating pressure, which results via the means 10 in the form of the control or on / off valve 10, is set via a pressure reduction stage 10 '. According to Figure 5 However, a lower operating pressure can also be set directly via the means 10 in the form of a control or on / off valve, since a low-pressure media supply 25 is present here.

The first roller cooling device according to Figure 1 with the cooling element 4 'is operated with a supply pressure between 3 and 30 bar and the second roller cooling with the cooling element 4 ″ with a supply pressure of less than 6 bar. The first roller cooling device according to FIG Figure 1 in a supply pressure range of 7 to 15 bar (high pressure media supply 24) and the second roller cooling device according to FIG Figure 2 in a supply pressure range of 1 to 5 bar (low pressure media supply 25).

Furthermore, the amount of water used is according to the second roller cooling device Figure 2 (So with the shell cooling) less than or equal to the amount of water of the first roller cooling device according to Figure 1 (Spray cooling). Advantageously, the second roller cooling device 4 ″ can optionally be operated via a pressure reduction device 10 ′ with a high pressure medium supply 24 or without a pressure reduction stage directly with a low pressure medium supply 25.

The pressure reduction can be implemented in the form of a throttle valve, a pressure regulating or limiting valve or by means of other process valves for changing the pressure from a higher medium pressure supply to a lower operating pressure. The pressure reduction can be carried out with an additional pressure reduction stage or, for example, only with an existing control valve (see the Figures 3 to 5 ).

The support frame can be designed to be displaceable in the horizontal direction together with the respective built-in cooling devices, so that the various roller cooling devices with support frame 3 can each be moved back and forth from the roller as required.

1. a) Betreiben der Walzanlage mit Einsatz der ersten Walzenkühleinrichtung gemäß Figur 1, die im Traggerüst 3 befestigt ist und deren Medienversorgung mit einem ersten Betriebsdruckniveau (oberhalb des Druckniveaus der zweiten Walzenkühleinrichtung) betrieben wird;
2. b) Demontage der ersten Walzenkühleinrichtung, d. h. des Kühlelements 4';
3. c) Einbau der zweiten Walzenkühleinrichtung, d. h. des Kühlelements 4" in demselben Traggerüst 3, die mit derselben Medienversorgung mit einem zweiten Betriebsdruckniveau (unterhalb des Betriebsdruckniveaus der ersten Walzenkühleinrichtung betrieben wird) und bei der eine Druckverminderung zur Anpassung an die Medienversorgung von dem ersten Betriebsdruckniveau an das zweite Betriebsdruckniveau durchgeführt wird;
4. d) Optimieren oder Testen und/oder Betreiben der Walzstraße mit der zweiten Walzenkühleinrichtung mit der Medienversorgung entsprechend dem Schritt c);
5. e) Anpassen der Medienversorgung vom ersten hohen Versorgungsdruckniveau an das zweite niedrigere Versorgungsdruckniveau (d. h. Umbau der Medienversorgung oder Änderung der Einstellungen);
6. f) Ausbau der Druckreduzierstufe oder Veränderung der Druckreduzierung und Betreiben (ohne Druckverminderung) der zweiten Walzenkühleinrichtung mit einem niedrigen Betriebs- und Versorgungsdruckniveau entsprechend Schritt e).

The conversion steps from using the first roller cooling device with the cooling element 4 'to using the second roller cooling device with the cooling element 4 "can be carried out as follows:

1. a) Operation of the rolling mill using the first roll cooling device according to Figure 1 which is fastened in the supporting frame 3 and whose media supply is operated at a first operating pressure level (above the pressure level of the second roller cooling device);
2. b) dismantling the first roller cooling device, ie the cooling element 4 ';
3. c) Installation of the second roller cooling device, ie the cooling element 4 ″ in the same support frame 3, which is operated with the same media supply with a second operating pressure level (below the operating pressure level of the first roller cooling device) and in which a pressure reduction is carried out to adapt to the media supply from the first operating pressure level to the second operating pressure level;
4. d) Optimizing or testing and / or operating the rolling train with the second roller cooling device with the media supply in accordance with step c);
5. e) adapting the media supply from the first high supply pressure level to the second lower supply pressure level (ie converting the media supply or changing the settings);
6. f) Expansion of the pressure reduction stage or change in the pressure reduction and operation (without pressure reduction) of the second roller cooling device with a low operating and supply pressure level according to step e).

Regarding the possible modification states regarding the media supply for the various roller cooling devices (cooling elements 4 'or 4 "), refer to the Figures 3 to 5 Referenced.

If the roller cooling device is to be changed again, the converted roller cooling device (step c) can very easily be restored to its initial state at a later point in time and operated in accordance with step a).

When converting a first roller cooling device to a second roller cooling device, only the upper or only the lower roller cooling system or both sides can be changed.

The compatibility of the various devices and the easy interchangeability of the units in the same support frame allow a easy, quick and flexible conversion and the exchangeability of two different roller cooling devices.

If the second roll cooling device is shell cooling, it can also be provided that the shell shape is adapted to the diameter range of the respective roll stand of a multi-stand rolling train and the base body of the shell cooling is chosen to be the same for all stands. After optimizing a roll stand, the neighboring stands can easily be exchanged using the same method and using the same second roll cooling devices with shell shapes adapted to the diameter.

If a shell cooling system is used as a second roller cooling system and if this cooling device and its media outlet are tightly sealed off from its surroundings, then it can also be provided that neighboring units (support roller, chocks, possible cylinders, etc.) are cooled by small amounts of a cooling medium using, for example, spray cooling .

List of reference symbols:

1

Cooling device

2

roller

3

Shoring

4 '

Cooling element of the first type

4 "

Cooling element of the second type

5

Receiving element

6th

mechanical interface

7th

adapter

8th

fluidic interface

9

supply line

10

Means for adjusting the pressure / volume flow

10 '

Means for adjusting the pressure / volume flow

11

Scraper

12

Scraper

13

Travel cylinder

14th

Coolant supply

15th

Fastening screws

16

Attachment point cylinder / support frame

17th

Track for shoring

18th

Spray nozzles

19th

Cooling bowl

20th

jet

21st

Joint for cooling bowl

22nd

Linkage lever

23

Joint for linkage lever

24

High pressure media supply

25th

Low pressure media supply

W.

Rolling direction

Claims (13)

1. Rolling train for rolling a metallic material, comprising a cooling device (1) for cooling the rolls (2) of a roll stand and/or the material which is to be or has been rolled,
   characterised in that
   the cooling device (1) comprises at least one support structure (3) for at least one cooling element (4', 4"), wherein the support structure (3) is equipped with at least one receiving element (5) for reception of a cooling element (4', 4"), wherein the cooling device (1) comprises at least two cooling elements (4', 4") of different mode of construction and wherein a cooling element (4', 4") of a selected mode of construction is alternatively received at the receiving element (5).
2. Rolling train according to claim 1, characterised in that the cooling element (4') of one mode of construction is a spray bar for spraying cooling medium onto the roll (2) and/or the material to be rolled.
3. Rolling train according to claim 1, characterised in that the cooling element (4") of one mode of construction is at least one cooling nozzle with a cooling jacket for the application of cooling medium to the roll (2).
4. Rolling train according to claim 1, characterised in that the cooling element of one mode of construction is a high-turbulence cooling means.
5. Rolling train according to claim 1, characterised in that the cooling element of one mode of construction is a roll cooling means with a water curtain.
6. Rolling train according to claim 1, characterised in that the cooling element of one mode of construction is an ultra-high-pressure cooling means.
7. Rolling train according to claim 1, characterised in that the cooling element of one mode of construction is a roll cooling means with laminar tubelets.
8. Rolling train according to any one of claim 1 to 7, characterised in that the receiving element (5) of the support structure (3) has a mechanical interface (6) constructed for mechanical connection with an adapter (7) arranged at the cooling element (4', 4"), wherein the adapters (7) of all cooling elements (4', 4") are constructed to fit with the mechanical interface (6) of the receiving element (5).
9. Rolling train according to any one of claims 1 to 8, characterised in that the receiving element (5) of the support structure (3) has a fluid interface (8) constructed for fluid connection with the cooling element (4', 4").
10. Rolling train according to any one of claims 1 to 9, characterised in that at least one supply line (9) for cooling medium is arranged in the support structure (3), wherein the supply line (9) comprises means (10, 10') for setting the pressure of the cooling medium and/or the cooling medium volume flow.
11. Method of operating a rolling train with a cooling device (1) according to any one of claims 1 to 10, comprising the steps:

    a) operating the rolling train with use of at least one cooling element (4') of a first mode of construction, wherein cooling medium at a first pressure level and/or in a first volume flow is delivered by way of the cooling element (4');

    b) demounting the at least one cooling element (4') of the first mode of construction;

    c) mounting at least one cooling element (4") of a second mode of construction;

    d) operating the rolling train with use of at least one cooling element (4") of the second mode of construction, wherein cooling medium at a second pressure level and/or in a second volume flow, which differs from the first pressure level and/or from the first volume flow, is delivered by way of the cooling element (4").
12. Method according to claim 11, characterised in that a first cooling element (4') with a supply pressure between 3 bars and 30 bars, preferably between 7 bars and 15 bars, is used and that a second cooling element (4") with a supply pressure of less than 6 bars, preferably with a supply pressure between 1 bar and 5 bars, is used.
13. Method according to claim 11 or 12, characterised in that a second cooling element (4") is operated by way of a pressure reducing element (10') from a high-pressure medium supply (24).

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