EP3434383A1 - Scaffold cooler for cooling a steel strip in a rolling stand - Google Patents

Abstract

The invention relates to a scaffold cooler (20) for cooling a steel strip (50) in a rolling stand (11), instead of chocks (5a, 5b) and an upper and a lower work roll (5) by an operating side roll stand (1) of the rolling stand (11) can be installed. The object of the invention is to modify the prior art so that the time between the last pass in hot rolling and the beginning of the belt cooling can be reduced. This object is achieved by the scaffold cooler (20) according to claims 1 or 2.

Description

Field of engineering

The present invention relates to rolling mill technology, in particular to hot rolling and cooling a metallic strip, e.g. a steel strip, or sheet in a rolling mill. The rolling mill may, for example, be a finishing train for strip production or a hot rolling mill for sheet metal production.

On the one hand, the invention relates to a scaffold cooler for cooling a steel strip in a roll stand, which can be installed in the mill stand instead of chocks and an upper and a lower work roll.

On the other hand, the invention relates to a method for installing a scaffold cooler in a rolling stand, as well as a method for removing a scaffold cooler from a rolling stand.

For reasons of clarity, a roll stand with removed chocks and removed work rolls is referred to as a roll stand in this document. This nomenclature is obvious to the person skilled in the art and increases the clarity.

State of the art

As is known, during hot rolling, the hot rolling stock is plastically deformed in a roll gap by so-called work rolls, whereby, for example, the thickness of the rolled stock is reduced. After hot rolling, the rolled stock is typically cooled in a cooling line and then discharged from the mill train, eg as a coil or sheet.

The material properties of a hot-rolled strip are not only dependent on its chemical composition, but also depend very much on the chronological sequence of the processing steps in the hot rolling mill. In a cast-rolling compound plant, e.g. an Arvedi ESP system, it comes for example essential to the chronology of continuous casting, roughing, intermediate heating, finish rolling, cooling and coiling. When adjusting the structure or phase proportions of the rolled strip (the hot-rolled strip after finish rolling is referred to as finished strip), the time interval between the last roll pass in a rolling stand of the rolling train and the beginning of the cooling of the strip also plays a decisive role. In many cases, this time span should be as short as possible.

Hot rolling mills have a fixed number of rolling mills, so that due to the high technical complexity of these mills, it is not possible to remove one or more mills of the mill in the production of thick strip, and to add removed mills in the production of thin strip. Thus, a rolling mill i.A. Both suitable for the production of thicker and thinner tapes.

It is known that thick strips are transported slower in a rolling mill and less reduced in thickness than thin strips. As a result, for example, a thick strip is often already finish rolled before the last roll stand, for example in the second roll stand, whereas a thin strip in the same rolling mill is finish rolled only in the last, eg fifth, roll stand. In the former case, therefore, the rolling stands 3, 4 and 5 are driven up, so that the thick band passes through these stands without rolling. Due to the relatively slow transport speed of thicker strips and the fact that the last forming already takes place in one of the first rolling stands, but results in a relatively long period of time until the finished strip reaches the cooling section behind the last mill stand and is cooled there with a certain intensity. This long time span can do this result in thick tapes being unable to reach certain material properties, thereby limiting the rolling mill's product mix.

This problem is exacerbated in the endless operation of cast-rolling composite equipment, since the transport speed of the belt is indirectly proportional to the strip thickness. In addition, the intermediate or finished strip can not be accelerated on the roller table by the endless operation, since it is coupled to the continuous casting. This leads to the fact that the transport speed of a thick strip in an ESP plant can be in the range of 0.5 m / s or less and thus much slower than in other, non-endlessly operated hot rolling mills, the rolling stock before, at or can accelerate after passing through the rolling mill.

However, even in non-continuous (e.g., batch or semi-endless) operation of a hot rolling mill, the underlying problem can not be satisfactorily resolved because a change in belt speed is always accompanied by a change in temperature at the last pass in the finishing train. In addition, the dissolution of the endless coupling between the units of a hot rolling mill leads to many well-known problems, such as e.g. the threading and unthreading of the strip from the rolling stands and the cooling section, the bumps through the tape head and band foot, the different temperatures of tape head and band foot etc. Thus, this solution either eliminates completely or is at least not satisfactorily feasible.

How to overcome the problem of the long duration of thick tapes between the last pass and the start of cooling in hot rolling mills, especially in continuous cast-roll mills, is not apparent from the prior art.

Summary of the invention

The object of the invention is to modify the existing state of the art by means of an innovative solution for a hot rolling mill, in particular a cast-rolled composite plant and here in particular for an endlessly operated cast-rolled composite plant, such that the time span between the last Rolling during hot rolling and the beginning of the strip cooling can be reduced without one or more stands have to be removed from the hot rolling mill or rebuilt before the subsequent production of thin strips, distant rolling stands before the production of thick tapes. The solution aims to expand the product mix of the hot rolling mill and produce a wide range of high quality hot strip.

The device-related aspect of this object is achieved in each case by the scaffold cooler according to claim 1 or 2. Advantageous embodiments are the subject of the dependent claims.

Specifically, the solution is carried out by a scaffold cooler, which is suitable for cooling a hot strip in a rolling stand, wherein the scaffold cooler can be installed instead of chocks and an upper and lower work roll through an operator-side roll stand of the rolling mill in the rolling mill.

The term "scaffold cooler" refers to a cooling device that cools a variable intensity hot strip and can be installed in a mill stand instead of chocks and work rolls. The designation explicitly does not refer to a cooling device that cools the rolls of a rolling stand!

• einen unteren Wasserkasten und einen oberen Wasserkasten, wobei der untere Wasserkasten und der obere Wasserkasten jeweils einen Anschluss für ein Kühlmittel und mehrere, in der Tiefenrichtung des Gerüstkühlers angeordnete, Kühldüsen oder Kühlrohre aufweisen, sodass der untere und der obere Wasserkasten durch den jeweiligen Anschluss mit Kühlmittel versorgt, die Unterseite des Warmbands durch die Kühldüsen oder Kühlrohre des unteren Wasserkastens und die Oberseite des Warmbands durch die Kühldüsen oder Kühlrohre des oberen Wasserkastens abgekühlt werden können.

The scaffold cooler according to claim 1 comprises:

• a lower water tank and an upper water tank, wherein the lower water tank and the upper water tank each have a connection for a coolant and a plurality, arranged in the depth direction of the scaffold cooler, cooling nozzles or cooling tubes so that the lower and the upper water tank supplied through the respective connection with coolant, the underside of the hot strip through the cooling nozzles or cooling tubes of the lower channel box and the upper side of the hot strip through the cooling nozzles or Cooling tubes of the upper channel box can be cooled.

• einen unteren Wasserkasten und einen oberen Wasserkasten, wobei der untere Wasserkasten und der obere Wasserkasten jeweils einen Anschluss für ein Kühlmittel und zumindest einen, in der Tiefenrichtung des Gerüstkühlers verlaufenden, Kühlschlitz aufweisen, der untere und der obere Wasserkasten durch den jeweiligen Anschluss mit Kühlmittel versorgt, die Unterseite des Warmbands durch den Kühlschlitz des unteren Wasserkastens und die Oberseite des Warmbands durch den Kühlschlitz des oberen Wasserkastens abgekühlt werden können.

The alternative scaffold cooler according to claim 2 comprises:

• a lower water tank and an upper water tank, wherein the lower water tank and the upper water tank each have a connection for a coolant and at least one, extending in the depth direction of the scaffold cooler, cooling slot, the lower and the upper water tank supplied through the respective port with coolant, the underside of the hot strip can be cooled by the cooling slot of the lower channel box and the upper side of the hot strip by the cooling slot of the upper channel box.

Scaffolding coolers according to the invention may also have a combination of a plurality of cooling nozzles or cooling tubes and one or more cooling slots.

In both embodiments, the scaffold cooler can be installed in the mill instead of chocks and upper and lower work rolls, so that the mill stand with the scaffold cooler can cool the top and bottom of a hot strip with a given intensity. By this is meant a cooling, which is comparable to the cooling in one of the rolling mill downstream cooling section.

It is known to use between the rolling stands of a hot rolling mill interstitial cooling to dissipate the heat generated during the deformation in the material and to keep the strip temperature within acceptable limits. This cooling is usually not dimensioned to a cooling of the tape in the context of this invention to reach. To extend the cooled area, a combination of a scaffold cooler with an interstage cooling (which cools the belt only between the rolling stands) is possible and advantageous for certain requirements.

• mehrere, in der Tiefenrichtung des Gerüstkühlers angeordnete, Kühldüsen oder Kühlrohre, oder
• zumindest einen, in der Tiefenrichtung des Gerüstkühlers verlaufenden, Kühlschlitz

aufweist. Durch den jeweiligen Anschluss bzw. die jeweiligen Anschlüsse werden der untere und der obere Wasserkasten mit Kühlmittel versorgt. Die Abkühlung der Unter- und Oberseite des Warmbands erfolgt durch Kühldüsen oder Kühlrohre bzw. einen oder mehrere Kühlschlitze.For cooling, the scaffold cooler on an upper and a lower water tank, each having at least one connection for a coolant and

• several, arranged in the depth direction of the scaffold cooler, cooling nozzles or cooling tubes, or
• at least one, extending in the depth direction of the scaffold cooler, cooling slot

having. Through the respective connection or the respective connections, the lower and the upper water tank are supplied with coolant. The cooling of the lower and upper side of the hot strip is carried out by cooling nozzles or cooling tubes or one or more cooling slots.

For a simple installation and removal of the scaffold cooler, it is advantageous if the scaffold cooler has at least two guide surfaces, wherein the guide surfaces are connected to the lower or upper water tank, so that the scaffold cooler in the width direction of the rolling mill or the hot strip introduced into the rolling mill (For example, inserted) can be and preferably the scaffold cooler rests in the built state on the guide surfaces.

By means of the at least two guide surfaces which are connected to the upper and / or the lower water box, the scaffold cooler can be easily mounted in the width direction of the rolling stand, e.g. also rails, are brought into the rolling stand. After retraction of the scaffold cooler it may remain on the rails or e.g. be supported by the bending block. Preferably, the scaffold cooler is in the installed state on the guide surfaces.

Replacing the chocks and upper and lower work rolls with the scaffold cooler can reduce the time span between the finish rolling (ie the last rolling pass in the hot rolling mill) and the beginning of the strip cooling are drastically shortened, so that, for example, thick hot strips reach the necessary metallurgical properties (eg structure) and can be produced with high quality. In addition, the distance between the last rolling mill and the cooling section is already used for cooling.

If the scaffold cooler is installed or removed mainly during a stoppage of the rolling operation (e.g., when changing work rolls), it is advantageous if the scaffold cooler is made in one piece, preferably with the lower and upper water boxes interconnected by posts. In this embodiment, the scaffold cooler can be installed and removed as a unit.

If the scaffold cooler can also be installed or removed during the rolling operation, it is advantageous for the scaffold cooler to be designed in at least two parts, with the lower and upper water tank each having two guide surfaces. Thus, the upper part of the scaffold cooler can be installed with the upper water tank independent of the lower part of the scaffold cooler with the lower water box in the roll stand, whereby the installation is facilitated during the continuous rolling operation.

As an alternative to the two-piece embodiment, a one-piece design would also be possible, e.g. with a "C" shape of the scaffold cooler.

In the two-piece design of the scaffold cooler, the lower water tank can be introduced eg on exchange rails in the rolling mill and then remain on this or raised or lowered by these, whereas the upper water tank can be supported in operation on the bending blocks and raised or lowered by these can be. As a result, during operation, the gap be set between the outlet openings of the water tanks and the steel strip.

Simple guidance of the scaffold cooler is ensured if the lower water tank and / or the upper water tank each have two lateral support tabs, wherein each of the two support tabs has a guide surface.

Since it is often necessary, as seen in the width direction of the hot strip edge regions and the center region of the hot strip to cool different degrees, it is advantageous if the lower water tank and the upper water tank have at least two terminals. Thereby, the, e.g. The cooling nozzles associated with the edge regions are supplied with a lower pressure than the cooling nozzles assigned to the center region.

• Entfernen von Einbaustücken und einer oberen und einer unteren Arbeitswalze aus dem Walzgerüst;
• Einbau des Gerüstkühlers in das Walzgerüst, wobei der Gerüstkühler horizontal in Breitenrichtung des Walzgerüsts bzw. des Warmbands durch einen bedienseitigen Walzenständer eingebracht wird;
• Verbinden der Anschlüsse des oberen und unteren Wasserkastens mit einer Kühlmittelversorgung, sodass die Unter- und die Oberseite des Stahlbands durch ein Kühlmittel abgekühlt werden können.

A procedural aspect of the invention relating to the installation of a scaffold cooler in a roll stand is achieved in claim 8 by the following method steps:

• Removing chocks and upper and lower work rolls from the rolling stand;
• Installation of the scaffold cooler in the rolling stand, wherein the scaffold cooler is introduced horizontally in the width direction of the rolling mill or the hot strip by an operator-side roll stand;
• Connect the top and bottom water box connections to a coolant supply so that the bottom and top of the steel belt can be cooled by a coolant.

The connections can be made, for example, by means of flange connections, manually operated lever-arm couplings with hose connections or by automatic coupling when the scaffolding cooler is inserted.

In a non-endless rolling mill, it is expedient to install the installation of the scaffold cooler during a stoppage of the rolling mill.

Particularly in continuous cast-roll compound plants, e.g. of the type Arvedi ESP, it is advantageous if the installation of the scaffold cooler during the operation of a rolling mill, in particular the finishing train takes place.

According to one embodiment, a connection is supplied by a coolant under an overpressure of 2 to 5 bar.

According to a further embodiment, a connection is supplied by a coolant under an overpressure of 0.1 to 0.8 bar.

In the operation of a scaffold cooler, it is advantageous to supply the connection or the connections of the lower water box with a higher pressure than the connection or the connections of the upper water box. This can be done by separate pressure controls for the upper and the lower connection. Alternatively, this can also be done by flow controls so that the flow rate to the lower plenum is higher than to the upper plenum (e.g., 60% of the total amount of water is supplied to the lower plenum and 40% to the upper plenum).

The aforementioned pressure ranges are not mutually exclusive, e.g. The edge region of the hot strip can be cooled by a first connection with a coolant under a pressure of 0.1 to 0.8 bar, whereas the center region can be cooled by a second connection with a coolant under a pressure of 2 to 5 bar.

Advantageously, the production of a steel strip is carried out according to claim 13, wherein first rolled a first steel strip in at least two rolling stands of a hot rolling mill is then cooled, the first steel strip in a cooling section and the cooled first steel strip is discharged as a plate or reel. Then, a scaffold cooler according to the invention is installed in a rolling stand of the rolling train. After installation of the scaffold cooler in the rolling stand, a second steel strip is rolled in at least one rolling stand of the rolling mill, cooled the second steel strip in at least one roll stand by means of the scaffold cooler, cooled the cooled second steel strip in the cooling section, and discharged the cooled second steel strip.

• Trennen der Anschlüsse des oberen und unteren Wasserkastens von einer Kühlmittelversorgung;
• Ausbau des Gerüstkühlers aus dem Walzgerüst, wobei der Gerüstkühler horizontal in Breitenrichtung des Walzgerüsts aus einem bedienseitigen Walzenständer gebracht (z.B gezogen) wird; und
• Einbau von Einbaustücken und einer oberen und einer unteren Arbeitswalze in das Walzgerüst.

The procedural aspect of the invention relating to the construction of a scaffold cooler from a rolling stand is solved in claim 14 by the following method steps:

• Separating the connections of the upper and lower water box from a coolant supply;
• Removal of the scaffold cooler from the rolling stand, wherein the scaffold cooler is brought horizontally in the width direction of the roll stand from an operator-side roll stand (eg pulled); and
• Installation of chocks and an upper and a lower work roll in the mill stand.

The disconnection of the terminals may in turn be e.g. by flange connections, manually operated lever arm couplings with hose connection or by the automatic coupling when pushing out the scaffold cooler.

Depending on the plant type of the rolling mill or its mode of operation (endless or not endless), the scaffolding cooler can be removed during operation or during an interruption in the operation of a rolling train.

It is advantageous, the cooling performance of the scaffold cooler depending on the material (in particular the chemical composition), the rolling parameters (thickness and speed of the steel strip) as well as to be achieved Set steel quality model-controlled. Depending on the above-mentioned values, a cooling model delivers online, ie during operation of the hot rolling mill, one cooling water quantity each and possibly also a width-dependent cooling water distribution for the top and bottom of the hot strip. The pressure and / or the flow rate of the cooling medium through the scaffold cooler are controlled or adjusted so that the steel strip reaches the desired properties as best as possible after passing through the rolling stands with the built-in scaffold coolers and cooling in the cooling section.

Brief description of the drawings

• Fig 1 zwei Ansichten eines Walzgerüsts mit eingebauten Einbaustücken und Arbeitswalzen nach dem Stand der Technik,
• Fig 2 zwei Ansichten von Einbaustücken und Arbeitswalzen nach dem Stand der Technik,
• Fig 3 eine Seitenansicht eines Walzgerüsts vor einer Kühlstrecke nach dem Stand der Technik,
• Fig 4 eine Seitenansicht einer Fertigwalzstraße mit fünf Walzgerüsten vor einer Kühlstrecke nach dem Stand der Technik,
• Fig 5 eine Seitenansicht einer Fertigwalzstraße mit fünf Walzgerüsten, wobei in die letzten drei Walzgerüste je ein erfindungsgemäßer Gerüstkühler eingebaut ist,
• Fig 6 zwei Ansichten eines Gerüstkühlers,
• Fig 7 eine weitere Ansicht des Gerüstkühlers aus Fig 6,
• Fig 8 zwei Ansichten eines Walzgerüsts mit einem eingebauten Gerüstkühler,
• Fig 9a und 9b je eine Ansicht eines Gerüstkühlers mit einem Kühlschlitz,
• Fig 10 eine schematische Darstellung der Wasserwirtschaft für ein Walzgerüst mit einem eingebauten Gerüstkühler,
• Fig 11 ein Schnitt in Breitenrichtung durch ein Walzgerüst mit einem eingebauten Gerüstkühler,
• Fig 12 eine Ansicht eines Gerüstkühlers mit Kühlrohren anstelle von Kühldüsen,
• Fig 13 eine Vorderansicht eines Gerüstkühlers mit eingebautem Gerüstkühler und Abweiseblechen, und
• Fig 14 eine Ansicht eines einstückigen Gerüstkühlers in C-Form.

Further advantages and features of the present invention will become apparent from the description of non-limiting embodiments. The following schematically illustrated figures show:

• Fig. 1 two views of a roll stand with built-in chocks and work rolls according to the prior art,
• Fig. 2 two views of chocks and work rolls according to the prior art,
• Fig. 3 a side view of a roll stand in front of a cooling line according to the prior art,
• Fig. 4 a side view of a finishing train with five rolling stands in front of a cooling line according to the prior art,
• Fig. 5 a side view of a finishing train with five rolling stands, wherein in the last three rolling stands each a scaffolding cooler according to the invention is installed,
• Fig. 6 two views of a scaffold cooler,
• Fig. 7 another view of the scaffold cooler Fig. 6 .
• Fig. 8 two views of a rolling mill with a built-in scaffold cooler,
• FIGS. 9a and 9b one view of a scaffold cooler with a cooling slot,
• FIG. 10 a schematic representation of the water management for a rolling stand with a built-in scaffolding cooler,
• Fig. 11 a section in the width direction through a roll stand with a built-in scaffold cooler,
• FIG. 12 a view of a scaffold cooler with cooling tubes instead of cooling nozzles,
• Fig. 13 a front view of a scaffold cooler with built-in scaffold cooler and Abweiseblechen, and
• FIG. 14 a view of a one-piece scaffolding cooler in C-shape.

Description of the embodiments

The Fig. 1 left shows a side view of a rolling stand 11 with built-in chocks 4a, 4b for an upper and lower support roller 4 and built-in chocks 5a, 5b for an upper and lower work roll 5. The right representation of Fig. 1 shows the roll stand 11 in a schematic sectional view without chocks. A hot strip, not shown, here a steel strip is rolled in the rolling stand 11 by the work rolls 5, wherein the work rolls 5 are supported on the underlying support rollers 4. A bending block 6 can bend the work rolls 5 and thus adjust the profile or the flatness of the rolled hot strip. The chocks 4a, 4b, 5a, 5b, the so-called. AGC (short for Automatic Gap Control) cylinder 3 and the bending block 6 are installed in the two stator windows 2 of the roll stand 1. The hot strip is guided on a rolling table 10 and brought to the work rolls 5. In order to limit the temperature of the work rolls 5, at least one (here two) upper cooling head 8a and at least one (here two) lower cooling head 8b of the work roll cooling are provided before and after the work rolls 5. In addition, upstream of the roll stand 11, an upper cooling head of the inter-frame cooling 7a and after the rolling stand 11, a lower cooling head of the inter-frame cooling 7b installed. Of course, an upper and a lower cooling head of the intermediate stand cooling can also be arranged before and after the roll stand 11, respectively. A pivotable looper roller 9 can adjust the train in the hot strip. Thus, the temperature of the hot strip before and after rolling can be changed. Since rolling stands 11 are known with so-called scaffold installations, a further description of the state of the art is dispensed with.

In Fig. 2 On the left is a side view and on the right a front view of a chock 5a with an upper work roll 5 and a chock 5b with a lower work roll 5 shown. By the chocks 5a, 5b, the work rolls are mounted displaceably in the rolling stand.

The Fig. 3 shows the rolling stand 11 from Fig. 1 in a rolling mill. An unillustrated steel strip is fed in the transport direction TR on a roller table 12 to the rolling stand 11 and rolled in the nip between the two work rolls. After hot rolling, the rolled strip is again guided on the subsequent roller table 12 to a cooling section 45 with a plurality of cooling manifolds 13 and cooled there with adjustable intensity.

The Fig. 4 shows a possible situation when rolling a thick hot strip in a rolling mill 40 designed as a finishing train with five rolling stands 11. Since it is a thick hot strip, the last roll pass already in the third (ie in the middle) rolling mill 11 instead. The thickness of the hot strip is reduced from 45 mm to 20 mm. After rolling, the rolled finished strip leaves the middle stand 11 at a speed of 0.4 m / s. In the areas marked C, the finished strip can be cooled by the upper and lower cooling heads of the inter-frame cooling 7a, 7b. In the rolling stands 11 itself, the finished strip can not be cooled. The uncooled areas are marked NC. Since the horizontal distance between the frame center line of the third stand 11 and the beginning of the cooling section 45 with the cooling manifolds 13 is about 20 m, the rolled hot strip requires 50 s until it reaches the cooling section 45. This time is already too long for certain types of steel, so that the steel strip can no longer achieve the desired structure or phase properties. The interstage cooling (marked C in the figure) with the upper and lower cooling heads 7a, 7b (see Fig. 1 ) does not change anything because the cooling capacity is too low and the rolled hot strip on the way to the cooling section 45 is mostly not cooled.

The Fig. 5 shows the situation when hot rolling a thick steel strip in a rolling mill 40 designed as a finish rolling mill originally with five rolling stands 11. In the last three rolling stands, the chocks 5a, 5b and the work rolls 5 (see Fig. 1 ) and instead each a scaffold cooler 20 (details in the Fig. 6 to 11 ) installed per roll stand 1. The last roll pass takes place in the second rolling stand 11 from the left; the finished strip is intensively cooled in each of the three subsequent roll stands 1 by a scaffold cooler 20. By cooling the steel strip by means of the scaffold cooler 20, the finished strip is already cooled on the middle roll stand 1. This makes it possible to produce thick strips of special steel grades (eg sophisticated tube grades) that would not be producible without scaffold cooler 20.

In Fig. 6 two views of a scaffold cooler 20 are shown, namely left in a side view and right in a sectional view. The scaffold cooler 20 has an upper header 21a and a lower header 21b. The underside of the upper water box 21a and the upper side of the lower water box 21b are equipped with cooling nozzles 23, so that a hot strip, not shown here in the width direction B can be cooled. To further increase the cooling effect, seven cooling nozzles each are arranged one behind the other in the transport direction (see Fig. 6 right). The water boxes 21a, 21b have lateral support tabs 25, wherein the support tabs 25 of the water box 21b each have a guide surface 26. On these guide surfaces 26 of the scaffold cooler 20 can be retracted in the width direction B of the hot strip in a rolling stand, not shown here. The illustrated scaffold cooler 20 is made in one piece, wherein the upper and the lower water tank 21 a, 21 b are connected to each other by uprights 27. The cooling nozzles 23 are supplied with coolant by a total of four ports 22, with two ports 22 each supplying the upper and lower water tanks 21a, 21b.

In Fig. 7 is in addition a front view of the scaffold cooler of Fig. 6 shown. The cooling nozzles 23 are typically supplied with an overpressure of 2 to 5 bar. The cooling intensity is pressure-dependent and adjustable via the overpressure of the cooling medium.

In Fig. 8 is a roll stand 1 with a scaffold cooler 20 shown in a side view on the left and a sectional view on the right. The scaffold cooler 20 from the FIGS. 6 and 7 is in the installed state on the two guide surfaces 26 of the lower support plates 25 on guide rails in the roll stand 1 or on the opposite guides of the chock 4b of the lower support roller and can be on this and removed.

The FIGS. 9a and 9b show one to the FIGS. 6 and 7 alternative scaffold cooler 20, which has cooling slots 24 instead of cooling nozzles. Since the steel strip 50 is not cooled differently in its width direction B or in the depth direction T of the scaffold cooler 20, it suffices if the upper and lower water boxes 21 a, 21 b each have only one connection 22. The uprights 7 and the support straps are like in the FIGS. 6 and 7 executed.

In FIG. 10 a water line plan for the coolant supply of a roll stand 11 with a built-in scaffold cooler 20 is shown. A pump 30 fed from a tank 31 represents the coolant supply. The pressure of the cooling medium water is reduced by the pressure regulating valve 28 from 13 bar to 4 bar and after passing the open switching valve 29 and the flow control valves 32 via connections to the upper and the lower water tank 21a, 21b supplied. The top and bottom of a hot strip, not shown here, are cooled by cooling nozzles 23. In the installed state of the scaffold cooler 20 in the rolling stand 11, the switching valves 29 are closed for the supply of the cooling medium to the cooling heads for the work roll cooling. From an energetic point of view, it would be better to feed the scaffold cooler 20 through a separate cooling circuit without pressure reduction by pressure control valves 28, for example directly with a pressure between 0.1 to 5 bar. These are typical pressures of existing low-pressure cooling systems. Alternatively, it would also be possible to connect the scaffold cooler directly to the existing coolant supply of the rolling mill without pressure reduction.

In Fig. 11 schematically the installation of a scaffold cooler 20 in the roll stand 1 of a roll stand 11 is shown. After raising the AGC cylinder 3 and the chocks 4a for the upper back-up roll 4, the chocks for the work rolls and the work rolls were removed. Subsequently, the scaffold cooler 20 is horizontally in the width direction B of Rolling stand 11 inserted through the operator-side roll stand (shown here on the right). Finally, the connections 22 of the scaffold cooler 20 are connected to a coolant supply, so that an upper and a lower side of a hot strip, not shown, are cooled by the cooling nozzles 23.

The FIG. 12 shows a schematic section through a scaffold cooler 20 with cooling tubes 23a instead of cooling nozzles 23 (see Fig. 6 right). Cooling tubes 23a are typically operated with an overpressure between 0.1 and 1 bar, so that they can easily realize a so-called laminar cooling.

The removal of a scaffold cooler 20 from a roll stand 1 is not shown separately, since the steps for installation are simply performed in reverse order.

In the Fig. 13 is the covering of the edge regions of a steel strip 50, engl. edge masking, shown. In this case, at least one edge region of the steel strip 50, in the figure, there are four edge regions, by the insertion of a Abweiseblechs 33 or a groove between the cooling nozzles 23, cooling tubes 23 a (see Fig. 12 ) or the cooling slot 24 (see Fig. 9b ) of the scaffold cooler 20 and the surface of the steel strip 50, so that the edge portion is not cooled. The cooling water of the cooling nozzles 23 and cooling tubes is discharged to the outside in the width direction of the steel strip 50. The position of the Abweiseblechs 33 or the channel can be adjusted to manual or automatic (for example, by an actuator, not shown, which shifts the Abweiseblech 33 in the arrow direction) fine, so that overcooling of the edge regions is reliably prevented.

In FIG. 14 is an alternative scaffold cooler 20 to the scaffold cooler of Fig. 7 shown in C-shape. Since the C-shaped scaffold cooler 20 is open at one end in the widthwise direction B, the scaffold cooler 20 may be opened during the The rolling mill can be easily inserted and removed in a rolling stand. The connections 22 of the upper and lower water box 21a, 21b, the cooling nozzles 23 and the guide surfaces 26 are identical to Fig. 7 , As an alternative to the guide surfaces, the scaffold cooler 20 could also have wheels for guiding on a rail. The uprights 27 are arranged only at one end of the scaffold cooler, for example, the user-side end.

Although the invention has been further illustrated and described in detail by the preferred embodiments, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention.

LIST OF REFERENCE NUMBERS

1

roll housing

2

housing window

3

AGC cylinder

4

supporting roll

4a

Chock for the upper support roller

4b

Chock for the lower support roller

5

Stripper

5a

Chock for the upper work roll

5b

Chock for the lower work roll

6

bending block

7a

Upper cooling head of the interstate cooling

7b

Lower cooling head of the intercooler cooling

8a

Upper cooling head of the work roll cooling

8b

Lower cooling head of the work roll cooling

9

Looper role

10

roller table

11

rolling mill

12

roller table

13

Cooling distributor of a cooling line

20

scaffolding cooler

21a

Upper water tank

21b

Lower water tank

22

connection

23

cooling nozzle

23a

cooling pipe

24

cooling slot

25

carrying straps

26

guide surface

27

stayer

28

Pressure control valve

29

switching valve

30

pump

31

tank

32

Flow control valve

33

Abweiseblech

40

rolling train

45

cooling section

50

steel strip

B

Width direction of the roll stand

C

Chilled area

LC

Chilled area of the cooling line

NC

Uncooled area

T

Depth direction of the scaffold cooler

TR

Transport direction of the steel strip

Claims (16)

A scaffold cooler (20) for cooling a steel strip (50) in a rolling stand (11), wherein the scaffold cooler (20) instead of chocks (5a, 5b) and an upper and lower work roll (5) by an operating side roll stand (1) of the rolling stand (11), the scaffold cooler (20) comprises: a lower water box (21b) and an upper water box (21a), wherein the lower water box (21b) and the upper water box (21a) each have a connection (22) for a coolant and several, in the depth direction (T) of the scaffold cooler ( 20), cooling nozzles (23) or cooling tubes (23a), so that the lower and the upper water box (21b, 21a) through the respective port (22) supplied with coolant, the underside of the steel strip (50) through the cooling nozzles (23 ) or cooling tubes (23a) of the lower channel box (21b) and the top of the steel strip (50) can be cooled by the cooling nozzles (23) or cooling tubes (23a) of the upper channel box (21a). A scaffold cooler (20) for cooling a steel strip (50) into a rolling stand (11), wherein the scaffold cooler (20) instead of chocks (5a, 5b) and an upper and lower work roll (5) by an operating side roll stand (1) of the rolling stand (11), the scaffold cooler (20) comprises: a lower header tank (21b) and an upper header tank (21a), the lower header tank (21b) and the upper header tank (21a) each having a port (22) for a coolant and at least one, in the depth direction (T) of the scaffold cooler (20) extending cooling slot (24), so that the lower and the upper water tank (21b, 21a) supplied through the respective port (22) with coolant, the underside of the steel strip (50) through the cooling slot (24) of the lower channel box (21b) and the top of the steel strip (50) can be cooled by the cooling slot (24) of the upper water box (21a). Scaffold cooler (20) according to claim 1 or 2, characterized in that the scaffold cooler (20) has at least two guide surfaces (26), wherein the guide surfaces (26) with the lower water tank (21b) or the upper water tank (21a) are connected, so that the scaffold cooler (20) in the width direction (B) of the rolling stand (11) can be introduced into the rolling stand (11). Scaffold cooler (20) according to one of claims 1 to 3, characterized in that the scaffold cooler (20) is made in one piece, wherein the lower and the upper water tank (21b, 21a) are connected to each other by uprights (27). Scaffold cooler (20) according to one of claims 1 to 3, characterized in that the scaffold cooler (20) is designed at least in two pieces, wherein the lower and the upper water tank (21b, 21a) each have two guide surfaces (26). Scaffold cooler (20) according to claim 1 to 5, characterized in that the lower water tank (21b) and / or the upper water tank (21a) each have two lateral support tabs (25), wherein the support tabs (25) each have a guide surface (26). respectively. Scaffolding cooler (20) according to one of claims 1 to 6, characterized in that the lower water tank (21b) and the upper water tank (21a) each have two terminals, so that the edge regions through a first terminal (22) and the center region of the steel strip ( 50) can be cooled to different degrees by a second connection (22). Method for installing a scaffold cooler (20) according to one of the preceding claims in a roll stand (11), comprising the method steps: - Removing chocks (5a, 5b) and an upper and a lower work roll (5) from the rolling stand (11); - Installation of the scaffold cooler (20) in the rolling stand (11), wherein the scaffold cooler (20) horizontally in the width direction (B) of the rolling mill (11) by an operator-side roll stand (1) is introduced; and - Connecting the terminals (22) of the upper and lower water box (21b, 21a) with a coolant supply, so that the bottom and the top of the steel strip (50) can be cooled by a coolant. A method according to claim 8, characterized in that the installation of the scaffold cooler (20) during operation of a rolling train (40) takes place. A method according to claim 8, characterized in that the installation of the scaffold cooler (20) takes place during a business interruption of a rolling train (40). Method according to one of claims 8 to 10, characterized in that the coolant supplies at least one port (22) under a pressure of 2 to 5 bar. Method according to one of claims 8 to 11, characterized in that the coolant supplies at least one port (22) under a pressure of 0.1 to 1 bar. Method according to one of claims 8 to 12, wherein a hot rolling train (40) comprises a plurality of rolling stands (11), comprising the method steps: - hot rolling a first steel strip in at least two rolling stands (11) of the rolling train (40); - cooling the first steel strip in a cooling section (45); - discharging the cooled first steel strip; - Installation of a scaffold cooler (20) according to one of claims 1 to 7 in a roll stand (11) of the rolling train (40), wherein the installation of the scaffold cooler (20) according to any one of claims 8 to 12 takes place; Hot rolling a second steel strip in at least one rolling stand of the rolling train (40); - cooling the second steel strip in at least one rolling stand (11) by means of the scaffold cooler (20); - cooling the cooled second steel strip in the cooling section (45); - Feeding the cooled second steel strip. Method for removing a scaffold cooler (20) according to one of Claims 1 to 7 from a rolling stand (11), comprising the method steps: Separating the connections (22) of the upper and lower water box (21b, 21a) from a coolant supply; - Removal of the scaffold cooler (20) from the rolling stand (1), wherein the scaffold cooler (20) horizontally in the width direction (B) of the rolling mill (11) from an operator-side roll stand (1) is applied; - Installation of chocks (5a, 5b) and an upper and a lower work roll (5) in the roll stand (11). A method according to claim 14, characterized in that the expansion of the scaffold cooler (20) during the ongoing operation of a rolling train (40). A method according to claim 14, characterized in that the removal of the scaffold cooler (20) takes place during a stoppage of operation of a rolling train (40).

Images