WO2023217775A1

WO2023217775A1 - Two-roller casting device for creating a cast metal strip, and method for cooling and/or cleaning an outer surface of a casting roller of a two-roller casting device

Info

Publication number: WO2023217775A1
Application number: PCT/EP2023/062260
Authority: WO
Inventors: Wilfried Klos; Michael Breuer; Axel Weyer; Jörn HOFFMEISTER
Original assignee: Sms Group Gmbh
Priority date: 2022-05-13
Filing date: 2023-05-09
Publication date: 2023-11-16
Also published as: DE102022204686A1

Abstract

The invention relates to a two-roller casting device (10) for creating a cast metal strip (1), more particularly a steel strip, and to a method for cooling and/or cleaning an outer surface (A) of a casting roller (12) of a two-roller casting device (10). Such a two-roller casting device (10) comprises two casting rollers (12), which are each mounted to rotate about rotational axes (X₁; X₂) oriented axially parallel to one another and at the same height and to rotate in opposite rotational directions (D) to one another, and a shell-like cover element (13) which is adjacent to at least one casting roller (12) and has a shape which is adapted to complement the curve of the casting roller (12). A gap (15) is formed between the cover element (13) and the casting roller (12), wherein a cooling and/or cleaning medium (K) can be discharged into the gap (15) by means of a metering device (17).

Description

Two-roller casting device for producing a cast metal strip, and method for cooling and/or cleaning an outer surface of a casting roll of a two-roller casting device

The invention relates to a two-roller casting device for producing a cast metal strip according to the preamble of claim 1, and a corresponding method for cooling and / or cleaning an outer surface of a casting roll of a two-roller casting device.

According to the state of the art, the so-called “two-roll process” is known for thin strip casting, in which cast strip up to 10 mm thick is produced directly from the melt. A two-roller casting device is used here, which comprises two casting rolls which are rotatably mounted in the opposite direction of rotation to one another and form a casting gap between them. A cast strip produced in this way can be fed directly to at least one rolling stand to set the target thickness and homogenize the technological properties and be formed there. If necessary, the hot strip obtained in this way is thermally treated after rolling and finally wound up.

In the thin strip casting mentioned above, the casting rolls are the central part of the system. In addition to the surface quality of the cast strip, the shape of the casting roll also defines the cast strip geometry and thus the later hot strip geometry or the flatness quality to be achieved. With the underlying low cast strip thicknesses, there will be no material flow transverse to the rolling direction in the rolling process, i.e. the cast strip strip profile can no longer be changed in the further process without loss of quality.

Due to the high heat flow through the casting rolls, they are usually subject to thermal warping (crowning). This crowning then leads to an undesirable (in reverse) profile change of the belt. To reduce such a crowning of the casting roll, active actuators are known from the prior art. Here the casting roll is locally either by hydraulic Actuators or thermal expansion rings (electrically heated) are deformed in such a way that the crowning should be suitably compensated or corrected, which is known, for example, from WO 2018/141744 A1.

WO 02/49789 A1 shows a casting roll for casting metal strip in the casting gap of two variable-distance, parallel and coolable casting rolls. To influence the profile of the outer jacket of the casting roll, a shaft with a sleeve surrounding it at a radial distance and an outside jacket with a crowning of its circumferential surface that can be adjusted in the casting operation is proposed. For this purpose, annular pressure chambers are formed on the inside of the sleeve for hydraulic inflation of the same, which are formed between the sleeve and the attached bands.

In addition to the undesirable cambering of the casting roll, casting roll cleaning is also an important aspect for creating an optimal strip surface. In casting systems that contain one or two casting rolls, liquid steel is brought into contact with the cooled casting roll surface in order to solidify on it. Before the rotating casting roll comes into contact with the liquid steel again, it must be continuously cleaned to prevent the accumulation of metal oxides, slag or other contaminants on the casting roll surface.

Mechanical cleaning devices such as scrapers, brushes or cleaning belts are used to clean the surface of a casting roll, but it is difficult to ensure uniform cleaning over the entire length of the casting roll. The uneven cleaning has a negative impact on the quality of the poured product. In order to improve cleaning, it is known to distribute several cleaning devices side by side over the length of the casting roll, although there is a risk that joints will form that impair surface cleaning. The cleaning devices are objects that can cause scratches or wear on the surface of the casting roll.

From WO 2007/031135 A1 a device for continuous surface cleaning of rotatable casting rollers of a belt casting machine is known. This will The entire casting roll length is exposed to one or more laser beams in order to carry out effective casting roll cleaning. Furthermore, additional cleaning units for mechanical, chemical, galvanic and/or thermal cleaning of the casting roll surface on the circumference of a respective casting roll are known from this publication. These additional cleaning units only act locally on a respective associated casting roll with respect to or along its circumference, ie over only a comparatively small circumferential area of the casting roll.

Another alternative method for belt cleaning is known from CN 10087799 B. A brush roller is used as a cleaning unit to clean the surface of the casting roller.

The above-mentioned solutions according to the state of the art for cleaning or cooling casting rolls of a two-roll casting device each have the disadvantage that the structural equipment for compensating for the crowning of the casting rolls and the devices for cleaning the casting rolls require a high level of technical effort require, so that the purchase of these devices is relatively expensive. In particular, the transfer of the required cooling medium into a rotating casting roller, which can be achieved using suitable rotary feedthroughs, requires a corresponding design effort.

Accordingly, the invention is based on the object of optimizing the cooling of casting rolls of a two-roll casting device using simple means and at the same time achieving the effect of cleaning.

The above-mentioned object is achieved by a two-roller casting device with the features of claim 1 and by a method specified with the features of claim 12. Advantageous developments of the invention are defined in the dependent claims. A two-roller casting device according to the invention is used to produce a cast metal strip, in particular made of steel, and comprises two casting rollers, each of which is arranged around axes of rotation aligned axially parallel to one another and at the same height and rotatably mounted in the opposite direction to one another, and a shell-shaped cover element, which is arranged adjacent to at least one casting roller and has a shape that is complementary to the curve of the casting roller. A gap is formed between the cover element and the casting roller. A metering device is arranged adjacent to an end section of the cover element or to an opening of the gap, by means of which a cooling and/or cleaning medium can be dispensed into the gap.

In the same way, the invention provides a method for cooling and/or cleaning an outer surface of a casting roll of a two-roller casting device, which can be the aforementioned two-roller casting device. In any case, in this method according to the present invention, a cooling and/or cleaning medium is introduced into a gap formed between the outer surface of the casting roll and a cover element arranged adjacent thereto.

According to its name, in the sense of the present invention, the cooling and/or cleaning medium used here can serve either for cooling purposes or for cleaning purposes, or this medium is used to simultaneously cool and clean a casting roller in a two-roller casting device reaches their outer surface.

The present invention is used in particular in the near-final dimension production of hot strip made of steel. This means that the metal strip, which is produced using a two-roll casting device, is then a steel strip which is cast from a molten steel. Alternatively, it is also possible for the present invention to be used for processing non-ferrous (non-ferrous) alloys. In any case, with that The present invention achieves an improvement in the product quality and an increase in the productivity of the strip casting process using the two-roll process.

The invention is based on the essential finding that a cooling and/or cleaning medium is introduced into a gap which is formed between an outer surface of a casting roll and a cover element arranged adjacent thereto. For this purpose, it is advisable to use a metering device, by means of which the cooling and/or cleaning medium can be appropriately dispensed into the gap. The fact that the shape of the cover element is complementary to the curve of the casting roll and thus the gap mentioned extends along a specific angular range of the casting roll ensures that the cooling and/or cleaning medium intensively covers the outer surface of the casting roll along this specific angular range wetted and thus leads to cooling and/or cleaning of the casting roller on its outer surface.

In an advantageous development of the invention, the cover element is arranged to be movable relative to a casting roller adjacent to it. It is therefore possible that the width of the gap that forms between the cover element and the outer surface of an adjacent casting roll depends on production parameters (enthalpy of the cooling medium, speed of the casting roll or casting speed, casting format, quality of the steel or the NE -Alloy and/or amount of cooling and/or cleaning medium) is specifically changed. Such an adjustment of the cover element relative to the casting roller can be controlled, preferably regulated, depending on the production parameters mentioned above.

In an advantageous development of the invention, the amount of cooling and cleaning medium that is introduced into the gap between the cover element and the outer surface of the casting roll can be adjusted depending on production parameters (enthalpy of the cooling medium, speed of the casting roll or Casting speed, casting format, and/or quality of the steel or non-ferrous alloy).

In an advantageous development of the invention, the predetermined angular range in which the cover element arranged in a lateral region of a casting roll extends around the outer surface of this adjacent casting roll is at least 20°. This ensures that the gap that forms between the cover element and the outer surface of the casting roll adjacent to it has a significantly sufficient length along the circumference of the casting roll in order to ensure the said intensive interaction of the outer surface of the casting roll with cooling and/or cleaning medium .

In an advantageous development of the invention, the predetermined angle range in which the cover element extends around the outer surface of a casting roll adjacent to it can also assume values of >20°. Preferably, this angle range can also be >30°, more preferably >45°, more preferably >60°, more preferably >90°, more preferably >100°, more preferably >120°, and more preferably =180° or even > be 180°. In this regard, it should be noted that the predetermined angular range can also assume any values that lie between the exemplary values mentioned above. This applies equally to the two-roller casting device according to the invention as well as to the method according to the invention for cooling and / or cleaning an outer surface of a casting roll of a two-roller casting device.

With regard to the cover element, which is arranged adjacent thereto in a lateral region of a casting roll, it should be noted that an opening for the gap is formed at the opposite end sections of the cover element. In the same way that a cooling and/or cleaning medium can be introduced into the gap through one of these openings, it is possible to introduce the cooling and/or cleaning medium at the opposite section of the cover element also emerges again through the other opening of the gap.

In an advantageous development of the invention, a receiving device is arranged adjacent to an opening of the gap, which is formed on a side opposite the metering device between the cover element and the casting roller, with which the cooling and/or cleaning medium transported through the gap is removed from the outer surface of the casting roller can be removed or taken up. Thus, with the help of such a receiving device, it is ensured that the cooling and/or cleaning medium is intensively removed from the outer surface of the casting roll when it emerges from the gap and is thereby appropriately caught without it reaching down onto a floor area or the like in an uncontrolled manner.

With regard to the above-mentioned receiving device, it should be emphasized at this point that, according to an advantageous development of the invention, it can be equipped with a suction device, a blow-off device and/or with a scraper. Here, a suction device preferably works via negative pressure. A blow-off device preferably works through the use of compressed air and/or fans. A scraper is expediently brought up to at least the outer surface of the casting roll or is in contact with the outer surface of the casting roll.

In an advantageous development of the invention, it is provided for the cover element that, viewed in the direction of a width or longitudinal extent of a casting roll adjacent to it, it has essentially the same length as this casting roll. This ensures that the gap in question extends over the entire width of the casting roll and to this extent the casting roll can be wetted with the cooling and/or cleaning medium over its entire width.

In an advantageous development of the invention, the metering device is designed in such a way that the introduction of a cooling and/or cleaning medium into the gap along the entire width of the casting roll is ensured. The metering device can expediently be equipped with a plurality of nozzles which are arranged along the width or longitudinal extent of the casting roller. These nozzles can be fluidly connected to a pressure generating device, so that a cooling and/or cleaning medium can be discharged from the nozzles under pressure into the gap.

In an advantageous development of the method according to the invention, the cooling and cleaning medium is sucked or blown off from the outer surface of the casting roll after it has emerged again from the gap between the outer surface of the casting roll and the cover element adjacent thereto. As already explained elsewhere above, this ensures that the cooling and cleaning medium is intensively removed from the outer surface of the casting roll when it emerges from the gap.

In an advantageous development of the invention, water or a water-based mixture can be used to cool the casting roll. The same medium can expediently also be used to clean the casting roller.

It is understood that for a two-roller casting device according to the present invention, a shell-shaped cover element can be provided for both casting rolls in order to form a gap adjacent to each casting roll. Accordingly, both casting rolls of the two-roller casting device can then be wetted with a cooling and/or cleaning medium, as explained, in order to bring about cooling and/or cleaning of the respective casting roll.

Further advantages of the present invention consist of the following aspects or features:

- Improvement of the strip profile or flatness of the metal strip produced;

- continuous cleaning of the casting roll(s), with improved belt surface; and or - inexpensive and simple basic concept of the required devices.

Exemplary embodiments of the invention are described in detail below using a schematically simplified drawing. Show it:

1 shows schematically a two-roller casting device for producing a cast metal strip according to a first embodiment of the invention,

Fig. 2, Fig. 3 each further details of the two-roller casting device from Fig. 1,

4 shows schematically a two-roller casting device for producing a cast metal strip according to a second embodiment of the invention, and

Fig. 5 shows schematically a casting-rolling system, which can be equipped with a two-roll casting device according to the invention according to Fig. 1 or Fig. 4.

Below, with reference to FIGS. 1-5, are preferred embodiments of a two-roller casting device 10 according to the invention for producing a cast metal strip, preferably made of steel, and a corresponding method for cooling and / or cleaning an outer surface of a casting roll of such a two-roller -Casting device 10 explained. The same features in the drawing are each provided with the same reference numbers. At this point it should be noted that the drawing is simply simplified and, in particular, shown without a scale.

Fig. 1 shows schematically a side view of the two-roller casting device 10 according to the invention according to a first embodiment. This casting device 10 comprises two casting rollers 12, which are each arranged around axes of rotation aligned axially parallel to one another and at the same height and rotatably mounted in the opposite direction of rotation D to one another. A shell-shaped cover element 13 is arranged adjacent to at least one casting roll 12, the shape of which is complementary to the curve of the casting roll 12 adjacent to it. The cover element 13 can be attached to a frame or frame 14 (see FIG. 2). A gap 15 is formed between the cover element 13 and the casting roller 12. Here, a gap width s is defined by the distance that the cover element 13 has laterally from the outer peripheral surface A of the casting roller 12.

The gap width s can be changed by a spatial displacement of the cover element 13, which is explained separately below.

3 illustrates that the cover element 13 is arranged in a lateral region of the casting roll 12 in such a way that it extends in an angular range W of at least 90° around the outer surface A of the casting roll 12 adjacent to it.

Further details of the two-roller casting device 10 according to the invention according to FIG. 1 are also illustrated in the side views of FIGS. 2 and 3. For example, in FIG. 2 the axes of rotation around which the two casting rollers 12 are rotatably mounted are designated here as “xr” and “X ₂ ”.

A casting gap G is formed between the two casting rollers 12, which can be filled from above with a molten steel 5 (see FIG. 2). Thus, when the two casting rollers 12 rotate in their respective direction of rotation D, a cast metal or steel strip is formed in the casting gap G, which emerges from the casting gap G on an underside of the casting rollers 12 and in a conveying direction F (see FIG. 1 , Fig. 2) is moved or transported.

The said molten steel 5 is provided by a ladle 2 and an intermediate container 3, each of which is arranged above the casting rollers 12. The intermediate container 3 is equipped with an outlet 4 through which the molten steel 5 can then be introduced into the casting gap G. The cover element 13 is arranged laterally from the casting roller 12 in such a way that there are openings at the end sections of the cover element 13

16 (see Fig. 2) form where the gap 15 is open accordingly upwards or downwards.

The cover element 13, viewed in the direction of a width or longitudinal extent of the adjacent casting roll 12, has essentially the same length as this casting roll 12. In other words, the cover element 13 has essentially the same width as the adjacent casting roll 12. An The cover element 13 is connected to the two end faces of the casting roll 12 with side plates (not shown) or comparable elements, so that the gap 15 is sealed there to the side. As a result, the gap 15 is, as explained, only open to the environment at the two openings 16.

Adjacent to an end section of the cover element 13 or to the upper opening 16 of the gap, a metering device 17 is arranged, by means of which a cooling and/or cleaning medium K can be dispensed into the gap 15.

With regard to the first embodiment of the two-roller casting device 10 according to the invention according to FIG. 1, it should be emphasized that the metering device

17 is arranged above it in relation to the axes of rotation Xi and X ₂ of the casting rollers 12 - seen in the vertical direction. Thus, a cooling and/or cleaning medium, which is symbolized with dots in FIG opposite to the direction of rotation D.

The metering device 17 is designed in such a way that the introduction of a cooling and/or cleaning medium K into the gap 15 along the entire width of the casting roll 12 is ensured. For this purpose, the metering device expediently comprises a plurality of nozzles which run along the width or Longitudinal extension of the casting roller 12 are arranged. Here, the nozzles can be fluidly connected to a pressure generating device (not shown), so that the cooling and/or cleaning medium K is discharged from the nozzles under pressure into the gap 15

In the first embodiment according to FIG. 1 or FIG. 2, a receiving device 18 is arranged adjacent to the lower opening 16 of the gap 15, namely on the side of the cover element 13 opposite the metering device 17. This makes it possible to pick up the cooling and/or cleaning medium K transported through the gap 15 from the outer surface A of the casting roller 12 when it emerges from the lower opening 16 of the gap 15.

As already explained elsewhere above, the receiving device 18 can be equipped with a suction device, a blow-off device and/or a scraper (not shown in each case). In any case, such a receiving device 18 ensures that the cooling and/or cleaning medium K, after it has emerged from the lower opening 16 of the gap 15, is then intensively removed from the outer surface A of the casting roller 12.

In the first embodiment according to Fig. 1 or Fig. 2, a drying unit 19 is arranged adjacent to the upper opening 16 of the gap 15 and - seen in the direction of rotation D of the casting roller 12 - downstream of the cover element 13. This drying unit 19 serves the purpose of completely removing cooling and/or cleaning medium K, which can continue to adhere to the outer surface A of the casting roller 12.

The drying unit 19 just mentioned can function on the principle of a blow-off device. Additionally or alternatively, it can be provided that the drying unit 19 comprises a scraper which is in contact with the outer surface A of the casting roller 12.

The invention now works as follows: During operation of the two-roller casting device 10 according to the invention, in order to cool the outer surface A, a cooling medium K is introduced into the gap 15 from above by means of the metering device 17, namely into its upper opening 16.

The cooling medium K is transported through the gap 15 in a transport direction which is symbolized by the arrow “T” in FIGS. 2 and 3. As can be seen, this transport direction T runs from top to bottom and thus in the direction of gravity and against the direction of rotation of the casting roller 12.

The cooling medium K is preferably water. In metallurgical facilities, cooling water is usually used as the cooling medium K, also based on water. Alternatively, the cooling medium can also be a water mixture or a mixture of cold gas and liquid nitrogen.

In the embodiment of Fig. 1, in which the cooling medium K is moved counter to the direction of rotation D of the casting roller 12 through the gap 15 in the transport direction T, the viscosity of the cooling medium K is suitably chosen to be so low that the effect of gravity (i.e. from top to bottom) is greater than the drag forces of the casting roller 12 (from bottom to top).

The transport of the cooling medium K through the gap 15 in the transport direction T is also promoted by the fact that the medium can be introduced into the gap 15 under pressure from above through the metering device 17 and its nozzles, as explained. The alignment of these nozzles is expediently set up parallel or almost tangential to the circumference of the casting roll. As a result of this arrangement of the nozzles, the liquid flow discharged from them adheres to the casting roll or its outer surface A.

The cooling of the outer surface A of the casting roll 12, ie its casting roll jacket, takes place by intensively wetting it with the cooling medium K, which is located in the gap 15, and in this respect an interaction between the Cooling medium K and the outer surface A of the casting roller 12 is achieved. This is preferably done over the entire barrel width of the casting roll 12. The casting roll jacket thereby cools directly and uniformly in the area of the shell-shaped cover element 13, which, as explained, is arranged laterally adjacent to the casting roll 12, in accordance with the amount of coolant K applied. The so-called crowning of the casting roll 12 is reduced by this cooling in that the thermal expansion of the casting roll 12 is reduced or prevented from the outset. The resulting temperature gradient between the outside area and the inside area of the casting roller 12 leads to a desired positive effect.

At the lower end of the shell-shaped cover element 13, the coolant K then emerges from the lower opening 16 of the gap. When this emerges from the lower opening 16 of the gap 15, the coolant is then picked up by means of the receiving device 18 and removed from the outer surface A of the casting roller 12, for example by suction or blowing.

Through the above-mentioned interaction between the outer surface A of the casting roller 12 and the cooling medium K in the gap 15, intensive cleaning of this outer surface A is achieved at the same time. In view of this, the medium, depending on its effect, can also be referred to as “cooling and cleaning medium K”.

In any case, the positive effect achieved for the present invention is that the same medium is used to clean the casting roller as is used to cool the casting roller 12. As already explained above, for example, water or a water-based mixture can be used for this purpose. Optionally, additional cleaning agents can also be added to the water (or the water-based mixture) with which the outer surface A of the casting roller 12 is cooled, so that intensive cleaning of the casting roller 12 on its outer surface A is achieved or improved. By means of the drying unit 19 it is achieved that the cooled and cleaned area of the outer surface A of the casting roll 12 is made dry or dehumidified before renewed contact with the steel melt 5. For example, the drying unit 19 can prevent water vapor explosions in wet casting rolls. 3, the drying unit 19 is arranged between the metering device 17 and the casting gap G in the first embodiment of the two-roller casting device 10. It is equivalent to this that the drying unit 19 is arranged adjacent to the upper opening 16 of the gap 15 - seen in the direction of rotation D of the casting roller 12 - downstream of the cover element 13.

As already explained above, the cover element 13 is arranged laterally from the casting roller 12 in such a way that it can be moved relative to the casting roller 12. For this purpose, the cover element 13 is operatively connected to adjusting means 20 (see FIG. 2), with which a lateral distance of the cover element 13 relative to the casting roller 12 and thus the gap width s can be variably adjusted. Accordingly, the cover element 13 can be attached to the frame 14 by means of a sliding bearing in order to enable the movement or adjustment of the cover element 13 just mentioned.

With the help of the adjusting means 20, the gap width s can be adjusted depending on production parameters (enthalpy of the cooling medium K, speed of the casting roller 12 or casting speed, casting format, quality of the steel or the non-ferrous alloy and/or quantity of cooling and/or Cleaning medium K) can be adjusted, either in the manner of a control or preferably in the manner of a regulation. In the latter case, the two-roller casting device 10 according to the invention is equipped with a control unit R (see FIG. 2), which is connected to the adjusting means 20 in terms of signaling (symbolized by a dotted line in FIG. 2). In addition, it should be noted that such a change in the gap width s can also take place during ongoing operation of the two-roller casting device 10 according to the invention. For the present invention, it can further be provided that the setting of the amount of cooling and cleaning medium K, which is introduced into the gap 15 between the cover element 13 and the outer surface A of the casting roll 12, depends on production parameters (enthalpy of the cooling medium K, Speed of the casting roll 12 or roll speed, casting format, and / or quality of the steel or the non-ferrous alloy). The control unit R can also be used here, which is then connected to the metering device 17 in terms of signaling and thus appropriately influences the amount of cooling and cleaning medium K that is discharged from the metering device 17.

A second embodiment of the two-roller casting device 10 according to the invention is shown in FIG. This second embodiment differs from the embodiment shown in FIGS. 1-3 in that the arrangement of the metering device 17 and the receiving device 18 is swapped. Specifically, this means that in the second embodiment, the metering device 17 is arranged below it in relation to the axis of rotation Xi _and the gap 15 is introduced from bottom to top and thus onto an outer surface A of the casting roller 12 in the same direction as its direction of rotation D. This also means that the transport direction T, with which the cooling and/or cleaning medium K is moved through the gap s, points upwards and thus corresponds to the direction of rotation D of the casting roller 12.

In the second embodiment of the two-roller casting device 10 according to the invention, the viscosity of the cooling and/or cleaning medium K, if it has a liquid form, is preferably chosen to be greater than in the first embodiment. This optimizes transport of the cooling and/or cleaning medium K through the gap s, counter to the direction of gravity. All other features that were explained above in connection with the two-roller casting device 10 according to the first embodiment also apply in the same way to the second embodiment. This includes not only the arrangement of the cover element 13 to the side of the casting roll 12, but in particular also the possibility of positioning the cover element 13 on the casting roll 12 or relative thereto in order to change the gap width s, preferably depending on production parameters, and / or setting the amount of cooling and/or cleaning medium K, also preferably depending on production parameters. In this respect, for the second embodiment according to FIG. 4, reference may be made to that of the first embodiment according to FIGS. 1-3 to avoid repetition.

At this point it should be pointed out separately that in FIGS. 1-4 the arrangement of a cover element 13 has been shown and explained for simplification purposes only for a casting roll 12 (namely for the one in the image area on the right). Accordingly, it is understood for the present invention that a cover element 13 can also be provided in the same way for the other casting roller 12 (namely the one in the image area on the left) (either according to the first embodiment of FIGS. 1-3, or according to the second embodiment of Fig. 4), or that a cover element 13 can also be arranged adjacent to both casting rolls 12, so that cooling and / or cleaning of both casting rolls 12 is ensured.

Finally, the schematic view of FIG. 5 makes it clear that a two-roller casting device 10 according to the invention can also be part of a casting-rolling system 100. Such a casting-rolling system 100 includes - seen in the conveying direction F of the metal strip 1 produced here - downstream of the casting device 10 at least one roll stand 6 for rolling the cast metal or steel strip 1, optionally supplemented by drivers 7 adjacent to the roll stand 6, a cooling section 8, a pair of scissors 9 and a reel H, with which the metal or steel strip 1 produced can then be wound up. Reference symbol list

1 steel band

2 pan

3 intermediate containers

4 discharge

5 molten steel

6 rolling stand

7 drivers

8 cooling section

9 scissors

100 casting-rolling plant

10 two-roller casting device

12 casting roll(s)

13 cover element

14 frame or frame

15 gap (between cover element 13 and casting roller 12)

16 opening (of the gap 15)

17 dosing device

18 recording facility

19 drying unit

20 adjustment means

A Outer surface (of a casting roll 12)

D Direction of rotation (of a casting roller 12)

F conveying direction

G casting gap

H Haspel

K Cooling and/or cleaning medium s Gap width

R control unit

T Transport direction (of the cooling and/or cleaning medium K within the gap 15) w angular range

Xi ; X ₂ rotation axis (a casting roll 12)

Claims

Patent claims

1. Two-roll casting device (10) for producing a cast metal strip (1), in particular a steel strip, comprising two casting rollers (12), each about axes of rotation (Xi; X ₂ ) aligned axially parallel to one another and at the same height and in opposite directions Direction of rotation (D) are arranged rotatably relative to one another, and a shell-shaped cover element (13) which is arranged adjacent to at least one casting roller (12) and has a shape which is complementary to the curve of the casting roller (12), characterized in that that a gap (15) is formed between the cover element (13) and the casting roller (12), and that a metering device (17) is arranged adjacent to an end section of the cover element (13) or to an opening (16) of the gap , by means of which a cooling and/or cleaning medium (K) can be dispensed into the gap (15).

2. Two-roller casting device (10) according to claim 1, characterized in that the metering device (17) is arranged above it in relation to the axis of rotation (Xi; X ₂ ) of the casting roller (12) - seen in the vertical direction, so that the cooling and/or cleaning medium (K) can be introduced into the gap (15) from top to bottom and thus onto an outer surface (A) of the casting roller (12) in the opposite direction to its direction of rotation (D).

3. Two-roller casting device (10) according to claim 1, characterized in that the metering device (17) is arranged below it in relation to the axis of rotation (Xi; X ₂ ) of the casting roller (12) - seen in the vertical direction, so that the cooling and/or cleaning medium (K) can be introduced into the gap (15) from bottom to top and thus onto an outer surface (A) of the casting roller (12) in the same direction as its direction of rotation (D).

4. Two-roller casting device (10) according to one of claims 1 to 3, characterized in that adjacent to an opening (16) of the gap, which is on a side opposite to the metering device (17) between the cover element (13) and the Casting roller (12) is formed, a receiving device (18) is arranged, with which cooling and / or cleaning medium (K) transported through the gap (15) can be removed or received from the outer surface (A) of the casting roller (12). .

5. Two-roller casting device (10) according to claim 4, characterized in that the receiving device (18) is equipped with a suction device, a blow-off device and / or with a scraper, the scraper at least up to the outer surface (A ) reaches the casting roller (12) or is in contact with the outer surface (A) of the casting roller (12).

6. Two-roller casting device (10) according to one of the preceding claims, characterized in that the cover element (13), viewed in the direction of a width or longitudinal extent of the adjacent casting roll (12), has essentially the same length as this Casting roller (12).

7. Two-roller casting device (10) according to one of the preceding claims, characterized in that the metering device (17) is designed such that the introduction of a cooling and / or cleaning medium (K) into the gap (15) along the entire width of the casting roll (12) is guaranteed.

8. Two-roller casting device (10) according to claim 7, characterized in that the metering device (17) comprises a plurality of nozzles which are arranged along the width or longitudinal extent of the casting roller (12), preferably that the nozzles are fluidic are connected to a pressure generating device, so that a cooling and/or cleaning medium (K) can be discharged from the nozzles under pressure into the gap (15).

9. Two-roller casting device (10) according to one of the preceding claims, characterized in that adjacent to the upper opening (16) of the gap (15) and - seen in the direction of rotation (D) of the casting roller (12) - downstream of that Cover element (13), a drying unit (19) and / or a scraper are arranged to remove cooling and / or cleaning medium (K) adhering to the outer surface (A) of the casting roller (12).

10. Two-roller casting device (10) according to one of the preceding claims, characterized in that the cover element (13) is arranged in a lateral region of the casting roller (12) and is in an angular range (W) of at least 20 ° the outer surface (A) of the adjacent casting roller (12) extends around, preferably that the angular range (W) is at least 45 °.

11. Two-roller casting device (10) according to one of the preceding claims, characterized in that the cover element (13) is movably attached relative to the casting roller (12) and is connected to adjusting means (20) with which a lateral distance of the cover element ( 13) relative to the casting roller (12) and thus the gap width (s) can be variably adjusted.

12. A method for cooling and / or cleaning an outer surface (A) of a casting roll (12) of a two-roll casting device (10), in particular according to one of claims 1 to 11, in which in between the outer surface (A) of the casting roll ( 12) and a gap (15) formed in a cover element (13) arranged adjacent thereto, a cooling and/or cleaning medium (K) is introduced.

13. The method according to claim 12, characterized in that the cover element (13) is arranged in a lateral area of the casting roll (12) and is in an angular range (W) of at least 20 ° around the outer surface (A) of the adjacent casting roll (12) extends around. Method according to claim 12 or 13, characterized in that a cooling and/or cleaning medium (K) - viewed in the vertical direction - is introduced into the gap (15) from above, so that the cooling and/or cleaning medium (K ) is transported downward through the gap (15) in the direction of gravity and against the direction of rotation (D) of the casting roller (12). Method according to claim 12 or 13, characterized in that a cooling and/or cleaning medium (K) - viewed in the vertical direction - is introduced into the gap (15) from below, so that the cooling and/or cleaning medium (K ) is transported upwards through the gap (15) against the direction of gravity and in the direction of rotation (D) of the casting roller (12), preferably that the cooling and / or cleaning medium (K) has a viscosity > water. Method according to one of claims 12 to 15, characterized in that the gap width (s) depends on production parameters (speed of the casting roll (12) or roll speed, casting format, quality of the steel or the non-ferrous alloy and / or amount of cooling - and / or cleaning medium (K)) is adjusted by the cover element (13) being controlled, preferably adjustable, relative to the casting roller (12). Method according to one of claims 12 to 16, characterized in that the adjustment of the amount of cooling and cleaning medium (K) that enters the gap (15) between the cover element (13) and the outer surface (A) of the casting roll (12) is introduced, depending on production parameters (enthalpy of the cooling medium K, speed of the casting roller (12) or casting speed, casting format, and / or quality of the steel or the non-ferrous alloy). Method according to one of claims 12 to 17, characterized in that the cooling and cleaning medium (K) after it has emerged from the gap (15) again between the outer surface (A) of the casting roller (12) and the adjacent cover element (13), is sucked or blown off from the outer surface (A) of the casting roller (12). 19. The method according to any one of claims 12 to 18, characterized in that water or a water-based mixture is used to cool the casting roll (12), preferably that the same medium is used to clean the casting roll (12) as for cooling.