US20090250187A1

US20090250187A1 - Device for Producing a Metal Strip by Continuous Casting

Info

Publication number: US20090250187A1
Application number: US12/227,557
Authority: US
Inventors: Jürgen Seidel; Peter Sudau; Jürgen Merz; Matthias Kipping
Original assignee: Individual
Current assignee: SMS Siemag AG
Priority date: 2006-05-26
Filing date: 2007-05-23
Publication date: 2009-10-08
Also published as: DE102007022930A1; KR20090016478A; EP2032285A1; JP2009538228A; TW200806406A; WO2007137741A1; RU2393940C1; KR101077065B1; AR061204A1; EP2032285B1

Abstract

The invention relates to a device for producing a metal strip (1) by continuous casting, using a casting machine (2) in which a slab (3) is cast. At least one milling machine (4) is arranged in the direction of transport (F) of the slab (3) behind the casting machine (2). At least one surface of the slab (3), preferably two surfaces which are opposite to each other, can be milled in said milling machine. According to the invention, in order to obtain high quality surface machining by milling, in particular in relatively rigid slabs, a shaving conveying device (6) is arranged in the region of at least one milling cutter (5) of the milling machine (4) enabling the milled shavings (7) to be removed from the region of the milling cutter (5) in the direction (Q) perpendicular to the direction of transport (F) of the slab (3).

Description

The invention pertains to a device for producing a metal strip by continuous casting, with a casting machine, in which a slab is cast, where at least one milling machine, in which at least one surface of the slab and preferably two opposite surfaces can be milled off, is set up downstream of the casting machine with respect to the transport direction of the slab.
During the continuous casting of slabs in a continuous casting machine, surface defects such as oscillation marks, casting flux defects, or longitudinal and transverse surface cracks can form. These occur in conventional and in thin-slab casting machines. Depending on the purpose of the finished strip, parts of the conventional slabs are therefore flame-descaled. Many slabs are descaled in their entirety at the customer's request. The demands on surface quality of thin-slab machines are continuously increasing.
Suitable methods for processing the surface include flame descaling, grinding, and milling.
Flame descaling suffers from the disadvantage that the flashed-off material has a high oxygen content and therefore must be reprocessed before it can be melted down again. In the case of grinding, slivers of metal mix with the dust from the grinding wheel, which means that the ground-off material must be disposed of. Both methods are difficult to adapt to the given transport speed.
Processing the surface by means of milling therefore seems a logical choice. The hot millings are collected, and they can be briquetted and easily remelted without workup and thus fed back into the production process. The rotational speed of the milling cutter can also be easily adapted to the transport speed (casting speed, feeding speed into the finishing). The inventive device of the type indicated above is therefore based on milling.
A device of the type indicated above with a milling machine which is set up downstream of the continuous casting machine is known. Reference is made in this respect to CH 584 085 and to DE 199 50 886 A1.
A similar device is also disclosed in DE 71 11 221 U1. This document describes the processing of aluminum strip by making use of the casting heat. The machine is connected to the casting installation.
The in-line removal of the top and bottom surfaces or of only one surface of a thin slab (flame descaling, milling, etc.) just in front of a rolling train has already been proposed. See EP 1 093 866 A2.
Another embodiment of a surface milling machine is described in DE 197 17 200 A1. Among other things, this document deals with the adjustability of the milling contour of the milling device, which is set up downstream of the continuous casting system or upstream of a rolling train.
Another arrangement of an in-line milling machine in a conventional hot-strip mill for treating a near-net strip and its design are proposed in EP 0 790 093 B1, in EP 1 213 076 B1, and in EP 1 213 077 B1.
When the surfaces of thin slabs are treated in a so-called CSP plant, approximately 0.1-3.5 mm of the hot slab surface is removed from one or both sides in the processing line (“in-line”) as a function of the detected surface defects. So as not to decrease the output too much, the thin slab should be as thick as possible (H=60-120 mm).
Surface processing and the associated devices are not limited to thin slabs. On the contrary, they can also be used in-line downstream of a conventional thick slab casting system and also in the case of slabs which are cast in thicknesses ranging from more than 120 mm to 300 mm.
The in-line milling machine is not generally used for all of the products of a rolling program but rather only for those in which higher demands are made on surface quality. This is advantageous for output reasons, reduces the wear of the milling machine, and is therefore a sensible approach.
So that good surface quality will be obtained after the slab is milled, it is important that the milling process, which is usually conducted on both the top and the bottom surfaces of the slab, take place under favorable process conditions.
This is no longer the case, however, when there are too many chips in the area of the milling cutter or cutters. This makes the milling process difficult, especially in the area of the top surface of the slab. The chips being cut away here fly off from the tool and fall onto the surface of the strip.
It is therefore known from DE 101 49 573 A1 and from DE 603 00 800 T2 that, to solve this problem, the strip to be process can be turned over so that both sides of the strip can be processed from underneath. On the bottom surface, the chips are removed from the slab automatically, as it were, by the force of gravity and can be easily collected in a hopper and carted off. This possibility does not exist, however, in the case of slabs with relatively high intrinsic rigidity. To prevent particles from being rolled into the surface, the chips and milling dust must be completely removed, but this causes problems in the case of rigid slabs.
The present invention is therefore based on the goal of improving a device for the production of metal strip by continuous casting in association with a milling machine in such a way that even intrinsically rigid slabs can receive optimal treatment. Measures are to be taken to ensure that optimal processing conditions are present during the milling of the slab, preferably both the top and bottom surfaces being treated, so that a high level of slab quality can be obtained.
This goal is achieved by the invention in that, in the area of at least one milling cutter of the milling machine, a chip conveying device is set up to convey the milled-off chips upward and/or in the direction transverse to the transport direction of the slab and thus out of the area of the cutter.
As a result, the slab being processed is kept almost completely free of chips, which improves the quality of the surface treatment.
The chip conveying device can be designed in various ways.
According to a first embodiment of the invention, the chip conveying device comprises at least one—preferably cooled—guide element, the slab-facing end of which, when viewed in the direction normal to the slab, extends at an acute angle to the direction transverse to the transport direction. In this case, the transverse conveyance of the chips therefore occurs as a result of the relative movement between the traveling slab and the guide element just mentioned.
This transverse chip conveyance is especially useful when downcut milling is practiced, that is, when the transport direction of the slab and the rotational direction of the milling cutter are the same.
Different alternative solutions will preferably be used, however, when milling is carried out primarily by the upcut method, that is, when the rotational direction of the milling tool and the transport direction of the slab are opposite each other. As one alternative, it is thus possible to use longitudinal spraying and the rotation of the milling tool to throw the chips onto a slanted guide element, along which the chips are then deflected by transverse spraying to the side, where they can be collected.
The guide element can comprise an edge of heat-resistant material, which can be laid against the surface of the slab. The guide element can also be supported with the freedom to pivot around a horizontal axis transverse to the transport direction of the slab. It can also be provided with cooling means or be connected to means by which it can be cooled. These cooling means can be designed as spray nozzles, which can spray a coolant onto the guide element.
According to another embodiment, the guide element comprises a trough with a lateral gradient at the end of the intake channel. By spraying longitudinally onto the slab and especially by spraying inside the transport channel, the chips are carried along by the water or compressed air and are discharged by way of the guide element and the discharge chute, optionally with the support of transverse spraying inside the trough.
In another preferred embodiment, the guide element, i.e., the chip collecting device, consists of a “water screw”. The chips are conveyed into this screw by longitudinal water sprays. A suitable orientation of the nozzles generates a transverse flow within the screw, from which the chips are ultimately discharged into the lateral discharge channel. The water can be applied to the guide element directly, after a deflection from a deflecting plate, or by direct deflection at the nozzle itself. The important point is that the flow is directed at the guide element in such a way that the chips are carried away.
According to an alternative and preferred embodiment of the invention, the chip conveying device comprises at least one conveyor belt, which runs transversely to the transport direction in the area of the surface of the slab.
In the case of the solution just mentioned, it is preferable for the conveyor belt to run horizontally in the area of the surface of the slab. The conveyor belt can also be designed as an endless belt which, when seen in the transport direction, passes completely around the slab. In this case, it has been found reliable for the conveyor belt to be deflected around a number of guide pulleys, at least one of which is driven.
The conveyor belt can be provided with cooling means or be connected to means by which it can be cooled. The cooling means are preferably designed as spray nozzles, which can spray a coolant onto the conveyor belt.
According to an alternative embodiment, the chip conveying device comprises at least one screw conveyor, which is set up in the area of the surface of the slab, and the longitudinal axis of which is transverse to the transport direction. The rotation of the screw makes transverse conveyance of the chips possible. Analogously, therefore, the chips are conveyed in the transverse direction.
In the embodiments of the invention discussed above, a baffle plate can be set up upstream or downstream of the chip conveying device. This baffle plate can be provided with a number of guide vanes, which face the milling tool.
The chip conveying device is preferably set up on positioning means, by which it can be raised and lowered in the vertical direction. Thus the chip conveying device can be placed at the optimal height with respect to an individual slab.
Instead of the use of a plain milling cutter, it is also possible, as an alternative, to use a face cutter, especially for the top surface of the slab. As a result of the rotation of the cutter around a vertical axis, the chips are automatically conveyed to the side without the use of guide elements. This transverse conveying effect is supported by the activation of cooling means for the cutting edges.
A guide element for conducting the milled-off chips onto a conveyor belt can also be provided on the bottom surface of the slab.
A rolling train can be set up downstream of the milling machine.
According to an elaboration, a guide channel is provided, through which the chips are drawn by suction from the top surface of the slab directly behind the milling gap, where the chips are conveyed away through a pipe extending transversely to the transport direction.
Finally, it is also possible to provide at least one magnet, by means of which the chips can be influenced as they are being carried away.
With the proposed solution, it is possible to ensure an optimal milling treatment and thus to achieve high surface quality without having to turn the slab over, which therefore can have any degree of intrinsic stiffness. This leads to a qualitative improvement in the production of slabs, especially thin slabs.

Exemplary embodiments of the invention are illustrated in the drawings:

FIG. 1 shows a schematic side view of a device for producing metal strip by continuous casting in association with a milling machine;

FIG. 2 shows a side view of a chip conveying device for the top surface of the slab with a conveyor belt, the area of the milling machine being shown on a larger scale than that of FIG. 1;

FIG. 3 shows a cross section along line A-B of FIG. 2;

FIG. 4 a shows a side view and

FIG. 4 b a top view of an alternative embodiment of the invention with a guide element for the chips set up on the top surface of the slab;

FIG. 5 shows a side view of an embodiment of the invention with a guide element for the chips set up on the bottom surface of the slab;

FIG. 6 shows a support plate for the slab, set up in the area of the milling cutter;

FIG. 7 shows a side view of a face cutter for the top surface of the slab;

FIG. 8 shows a top view of the face cutter arrangement;

FIG. 9 shows a side view of a chip collecting device for the top surface of the slab designed in the form of a “water screw” and a partial top view of same;

FIG. 10 shows a side view of another alternative embodiment corresponding to FIG. 4 with a trough and an outlet at the end of the collecting device;

FIG. 11 a shows a side view and

FIG. 11 b a top view of a simple device for conveying chips to the side by the movement of the slab during downcut milling; and

FIG. 12 shows another alternative embodiment of the invention with a suction device for chips.

FIG. 1 shows a device for producing a metal strip 1 by continuous casting. The metal strip 1, i.e., the corresponding slab 3, is continuously cast in a casting machine 2 by the known method. The slab 3 is preferably a thin slab. Immediately downstream of the casting machine 2, the slab 3 is subjected to a cleaning process in a cleaning system 20. After that, the surface is inspected by means of a surface measuring unit 21. The slab 3 then enters a furnace 22, so that it can be kept at the desired process temperature. A transverse conveyor 23 follows after the furnace.
Downstream of the furnace 22, i.e., of the transverse conveyor 23, the slab 3 arrives at a milling machine 4. In the present case, two milling cutters 5—spaced somewhat apart in the transport direction F—are installed, by means of which the bottom and top surfaces of the slab 3 can be milled off. A support roll 24 is provided opposite each of the active cutters to support the surface of the slab 3, i.e., one for the top surface and one for the bottom surface.
Downstream of the milling machine 4, a descaling spray 35 and a rolling train, represented by rolling stands 25 and 26, are installed.
In the present case, the primary goal is to keep the top and bottom surfaces of the slab as free as possible of the chips which are formed during the milling process by the milling cutters 5. If the chips are not removed thoroughly enough from the milling area, the surface of the slab 3 can be damaged. This is especially to be feared in the present case, because the slab 3 has such intrinsic stiffness that turning it around its longitudinal axis so only the downward-facing surface of the slab has to be milled is out of the question.
FIGS. 2 and 3 show a possible embodiment of the invention which can solve this problem.
As can be seen in FIG. 2, the milling cutter 5 mills off the top surface 8 of the slab 3. The slab 3 is supported from underneath by a support roll 24. As suggested in FIG. 2, the rotational direction of the milling cutter 5 (see arrow) during the milling process causes the chips 7 to fly toward the left in FIG. 2. There is the danger that chips 7 remaining on the surface of the slab can interfere with the milling process and negatively impact the quality of the treatment.
For this reason, a chip conveying device 6 is provided, which is intended to remove the chips 7 reliably. The chip conveying device 6 comprises, as its central component, a conveyor belt 9, as can be easily seen upon consideration of FIGS. 2 and 3 together. The endless conveyor belt 9 passes completely around the slab 3 (see FIG. 3). The upper part of the conveyor belt 9 passes just above the surface 8 of the slab 3.
The conveyor belt 9 is guided by four guide pulleys 10, at least one of which is driven. The belt itself consists of heat-stable material, because it comes in contact with the hot slab or passes just barely above it. It is therefore advantageous for the conveyor belt 9 to be cooled, for which purpose cooling means 11 are provided in this exemplary embodiment in the form of a spray nozzle. By means of the nozzle 11, a cooling medium (water) can be sprayed onto the conveyor belt 9 so that it does not become too hot.
So that the chips 7 are not flung too far away from the milling cutter 5, a baffle plate 12, which is flat and oriented vertically, is set up behind the conveyor belt 9.
So that the chips 7 striking the baffle plate 12 are guided optimally onto the conveyor belt 9, guide vanes 13 are mounted on the side of the baffle plate 12 facing the milling cutter 5.
The horizontally traveling part of the conveyor belt 9 is intended to pass as close as possible to the surface 8 of the slab 3. So that this can be adjusted as accurately as possible as a function of the actual slab to be treated, positioning means 14, which are indicated merely in schematic fashion, are provided, by means of which the entire chip conveying device 6 can be adjusted in the vertical direction.
To provide optimal support for the removal of chips from the surface 9 of the slab 3, a guide element 15′ (which is used here in conjunction with the conveyor belt 9) is also provided in this exemplary embodiment; this guide element could also be called a “stripper”. At the end facing the slab 3, the guide element 15′ has an edge 16 of especially heat-resistant material. During operation, this edge lies either on the surface of the slab or is held floating just above the surface.
It can also be seen in FIGS. 2 and 3 that, behind the milling cutter 5, there is a nozzle bar 27, consisting of several nozzles (see FIG. 2). With these nozzles, the movement of the chips toward the conveyor belt 9 can be supported by means of jets of water or compressed air. Liquid or gaseous medium (water or compressed air), which can also have a desirable cooling effect, can therefore be discharged through the nozzles.
It can be seen in FIG. 3 that the conveyor belt 9 conveys the chips 7 onto a second conveyor belt 28, from which the chips 7 are carried into a collection container 29.
FIG. 9 shows a side view and partial top view of another important embodiment of the invention. FIG. 9 presents an alternative chip conveying device 6 for the top surface of the slab. By means of a water jet S, which is applied through a nozzle bar 49, the milled chips are conveyed into a so-called water screw 54. The water can be sprayed from the nozzle bar 49 onto a baffle plate 52, where it spreads out and then flows in direction S toward the guide element 15.
Alternatively, it would also be possible to spray directly from the area of the baffle plate or to deflect the spray directly at the nozzle so that it proceeds in the desired direction S.
The goal is for the water jet to pick up the chips and to carry them along. It is effective to use a pressure of greater than 50 bars. The water jet S is not aimed in the direction directly opposite the transport direction F but instead has a certain component in the transverse direction, that is, toward the edge of the slab. This is achieved by a suitable angling or turning of the nozzle. The angling can be symmetric, so that the water flows laterally toward both sides within the conveying device 6. It is also possible, however, for the nozzles to be angled toward only one side (=discharge side).
As a result of the spiral or screw-like shape of the conveying channel 54 and the angled orientation of the spray direction 53, a tubular water vortex forms in the area R. As can be seen in the small diagram on the right in FIG. 9, which shows the view from direction B indicated in the diagram on the left in FIG. 9, the high flow velocity and the angled water feed cause the water 53 carrying the chips to flow in a spiral pattern toward the external discharge channel 51. The discharge channel 51 can be located on the drive side and/or on the operator's side, next to the edge of the slab 3′.
In addition, transverse spraying in the area R, that is, inside the chip conveying device 6, can also support the chip removal process. Chips which remain on the top surface of the slab between the guide plate 15 and the milling cutter 5 are conveyed onto the guide plate by the longitudinal spray 27. The chip conveying device 6 lies with its tip down on the slab or floats just above the slab surface. The guide element 15 is internally cooled to protect it from the heat or is thermally insulated from the slab 3. It is especially advantageous that, even though water is supplied through the nozzle bar 49 to convey the chips, the slab 3 undergoes hardly any cooling.
FIGS. 4 a and 4 b show two different views of another alternative embodiment. It should be noted that the guide element 15 shown here can be used by itself as a chip conveying device 6, or it can be used in combination with a conveyor belt according to FIGS. 2 and 3 (designated there as guide element 15′).
In FIGS. 4 a and 4 b, the guide element 15 for conducting the chips 7 away is provided on the top surface of the slab 3. The guide element 15 is formed out of sheet metal, which is provided at one end 18 with an edge 16 of heat-resistant material. This edge 16—looking in the normal direction N onto the slab 3 (see FIG. 4 b)—extends at an acute angle α to the direction Q transverse to the transport direction F. The angle is preferably in the range of 10-45°. The impact surface is also slanted toward the side.
As a result, the movement or flight of the chips to the plate 15 generates a transverse movement in direction Q, so that the chips 7 are flung away toward the side. The chips can fall downward laterally next to the slab 3, either directly into a collection container or onto a conveyor belt in analogy to the solution according to FIGS. 2 and 3.
The guide element 15 is supported around a horizontal axis 17, which extends in direction Q, transverse to the transport direction F. Thus—by means of positioning means (not shown; see double arrow in FIG. 4 a)—the guide element 15 can be positioned in such a way that the edge 16 either rests on the top surface of the slab or is held floating just above it.
The guide element 15 can be cooled by suitable means. Not only is it possible to cool it by means of spray nozzles from the outside, but it is also conceivable that internal cooling could be provided by means of appropriate cooling channels in the guide element 15.
In addition to the design as an edge 16 extending at an angle across the entire width of the slab 3, a plow-like design with two edge parts arranged to form an angle α to each other is also possible.
The sideward movement of the chips 7 can also be supported by auxiliary means. A blower for air, for example, or a water jet, by means of which the chips 7 can be deflected toward the side, would be suitable. High-pressure water or compressed air nozzles 27, 27′, which would be installed downstream of the milling cutter 5 or at the side, are also conceivable.
In all of the cases illustrated, the guide element 15 can consist of a single part. It could also consist of several individual segments extending across the width of the slab. It can rest by its own weight on the slab 3. It can also be pressed by spring elements onto the top surface of the slab. As previously mentioned, it is also possible for the edge 16 of the guide element 15 to be positioned so that it floats just above the top surface of the slab.
The conveyance of the chips in the transverse direction Q can also be promoted by the milling process itself as a result of the slanted orientation of the cutting edges of the cutter 5.
In the solution according to FIG. 10, as also in the previously explained alternatives, the chips are conveyed by a conveyor jet 27, 49 by way of a guide element 15 into the chip conveying device 6. At the end of the device 6, there is here alternatively a discharge chute, into which the chips slide or into which they are flushed in the lateral direction.
To promote the removal of the chips from the top surface of the slab, a face cutter 36 is provided in the solution according to FIGS. 7 and 8 instead of the previously described plain milling cutter 5. The cutter 36 is located above the slab 3. Cutting edges 37 are attached to the outer area of the bottom surface of the disk-shaped base body. The diameter of the face cutter 36 is somewhat larger than the maximum width of the slab. The chips are conveyed to the side 45 by the rotation of the cutter 36. Laterally next to the strip, the chips are collected in a hopper 48 and carried away.
So that the slab 3 rests stably in the cutting area of the cutter 36, an internally cooled transfer table 40 is provided. A driver 38 take care of advancing the slab 3. A cutting edge cooling system 39 takes care of cooling the face cutter 36 and the cutting edges. By way of a rotary coupling or drive shaft 44, water or emulsion is supplied to the base body of the cutter. To ensure optimal cooling of the cutter 36 and to promote the conveyance of the chips to the side, cooling bores 39, which proceed radially from the center to the cutting edges, are introduced into the base body. The transverse forces (axial forces) which result from the angled orientation of the cutting edges during the milling process are absorbed by lateral roller guides 42. FIG. 7 shows a side view of the driver and the face cutter on the top surface of the slab 3. FIG. 8 shows a top view of the slab 3 and the face cutter 36 and also of the lateral roller guides 42.
FIGS. 11 a and 11 b show the guide element 15 resting on the surface of the slab. In the case of downcut milling, therefore, a simple process of chip conveyance in the sideways direction occurs as a result of the angling a of the lateral surfaces of the guide element 15. As a result of the relative movement between the traveling slab 3 and the previously mentioned guide element 15, the chips 7 are carried toward the sides and, as previously explained, carried onward from there. This mechanism functions when the rotational direction 43 of the milling and the transport direction F of the slab are the same.
In all of the embodiments, it is also possible to use lateral roller guides 30 (see FIG. 2) to keep the slab 3 centered in the line. The lateral roller guides 30 can be set up both upstream and downstream of the milling machine or of the milling cutters 5.
FIG. 5 shows a guide element 15 for the bottom surface of the slab 3. It should be noted that it is obviously much simpler to remove the chips 7 from the bottom surface of the slab than from the top surface because it can be done by gravity. Nevertheless, a guide element 15 is provided here as well, which can pivot around a horizontal transverse axis 17. Otherwise, the explanations given in conjunction with FIG. 4 apply in analogous fashion.
The guide element 15 is cooled by cooling means 19 (spray nozzles for water or nozzles for air). A conveyor belt 9 is provided underneath the guide element 15. The chips 7 being conveyed on this belt can be cooled by cooling means 31 (spray nozzle).
FIG. 6, furthermore, shows a detail which improves the process reliability of the arrangement. Underneath the slab 3, a support plate 32 is arranged, which can be internally cooled and raised and lowered. On the opposite side of the slab 3, a movable contact roll 33 is set up to produce a light pressing force. The surface 34 of the support plate 32 can be designed with grooves to reduce the contact surface area. With the device shown in FIG. 6, the slab can be threaded into the processing gap between the milling cutter 5 and the support roll 24 with optimum results.
According to another alternative embodiment of the basic idea of the invention, namely, the removal of chips from the top surface of the slab, use is made of suction. This is illustrated in FIG. 12. For this purpose, a guide channel consisting of several guide plates 15 is set up directly downstream of the milling gap. The chips which fly into the channel are then also drawn by suction and carried away transversely through a pipe. The pipe and the suction channel are thermally insulated from the slab. To damp the noise, furthermore, the channel and the pipe are covered externally by damping mats.
To support the conveyance of the chips to the side or to help move the chips in the desired direction, permanent magnets or electromagnets can be used (not shown). The chips cool down very quickly below the transformation temperature, which means that they are subject to the influence of magnets.

LIST OF REFERENCE SYMBOLS

1 metal strip
2 casting machine
3 slab
3′ edge of slab
3″ center line of slab or machine center
4 milling machine
5 milling cutter
6 chip conveying device
7 chips
8 surface of the slab
9 conveyor belt
10 guide pulley
11 cooling means (spray nozzle)
12 baffle plate
13 guide vanes
14 positioning means
15 guide element
15′ guide element
16 edge
17 axis
18 end of the guide element
19 cooling means
20 cleaning system
21 surface measuring device
22 furnace
23 transverse conveyor
24 support roll
25 roll stand
26 roll stand
27 nozzle bar for longitudinal spraying
27′ nozzle bar for transverse spraying
28 second conveyor belt
29 collecting container
30 lateral roller guide
31 cooling means
32 support plate
33 contact roll
34 surface
35 descaling spray
36 face cutter
37 cutting edge
38 driver
39 cutting edge cooling, cutter cooling
40 transfer table
41 roller table roller
42 lateral roller guide
43 rotational direction
44 rotary coupling, drive shaft
45 chip conveyance to the side
46 milling the top surface
47 milling the bottom surface
48 chip collecting hopper
49 nozzle bar for chip conveyance
50 roller table roller
51 discharge channel
52 deflecting plate or deflection angle
53 flow direction of the water in the water screw
54 water screw, chip collecting device
55 thermal insulation or cooling
F transport direction
D rotational direction of the plain milling cutter
Q transverse direction
N normal direction
α angle
S spray direction
R area of the tubular water vortex

Claims

1. A device for producing a metal strip (1) by continuous casting, with a casting machine (2), in which a slab (3) is cast, where at least one milling machine (4), in which a least one surface of the slab (3) can be milled off, is set up downstream of the casting machine (2) with respect to the transport direction (F),

wherein, in the area of at least one milling cutter (5) of the milling machine (4), a chip conveying device (6) is set up, which conveys the milled-off chips (7) upward and/or in the direction (Q) transverse to the transport direction (F) of the slab (3) out of the area of the milling cutter (5),

where the chip conveying device (6) comprises at least one screw conveyor, which is set up in the area of the surface (8) of the slab (3) and the longitudinal axis of which is transverse to the transport direction (F), or

where the chip conveying device (6) comprises at least one guide element (15), the slab (3)-facing end (18) of which, when viewed in the direction (N) normal to the slab (3), forms an acute angle (a) to the direction (Q) transverse to the transport direction (F), or

where the chip conveying device (6) comprises at least one conveyor belt (9), which extends transversely to the transport direction (F) in the area of the surface (8) of the slab (3).

2. A device according to claim 1, wherein a trough with a gradient is provided at one of the of the guide element (15).

3. A device according to claim 1, wherein the conveyor belt (9) extends horizontally in the area of the surface (8) of the slab (3).

4. A device according to claim 1, wherein the conveyor belt (9) is designed as an endless belt and, when seen in the transport direction (F), passes completely around the slab (3).

5. A device according to claim 4, wherein the conveyor belt (9) is deflected over a number of guide pulleys (10), at least one of which is driven.

6. A device according to claim 1, wherein the conveyor belt (9) is provided with cooling means (11) or is connected to means by which it can be cooled.

7. A device according to claim 6, wherein the cooling means (11) are designed as spray nozzles, which can spray a cooling medium onto the conveyor belt (9).

8. A device according to claim 1, wherein, with respect to the transport direction (F), a baffle plate (12) is set up upstream or downstream of the chip conveying device (6).

9. A device according to claim 8, wherein the baffle plate (12) is provided with a number of guide vanes (13), which face the milling cutter (5).

10. A device according to claim 1, wherein the chip conveying device (6) is set up on positioning means (14), by which it can be raised or lowered in the vertical direction and/or pivoted.

11. A device according to claim 1, wherein a guide element (15′), by means of which chips (7) can be conducted from the surface (8) of the slab (3) onto the chip conveying device (6), is set up.

12. A device according to claim 11, wherein the guide element (15′) comprises an edge (16) of heat-resistant material, which can be laid against the surface (8) of the slab (3).

13. A device according to claim 11, wherein the guide element (15′) is pivotably supported around a horizontal axis (17) transverse to the transport direction (F) of the slab (3).

14. A device according to claim 11, wherein the guide element (15′) is provided with cooling means (19) or is connected to means by which it can be cooled.

15. A device according to claim 14, wherein the cooling means (19) are designed as spray nozzles, which can spray a cooling medium onto the guide element (15′).

16. A device according to claim 1, wherein high-pressure water or compressed air nozzles (27, 49) are also provided, which support the transport of the chips.

17. A device according to claim 16, wherein the high-pressure water or compressed air nozzles (27, 49) convey chips onto the conveyor belt (9) or to a guide element (15, 15′) or to a screw-shaped receiving element (54).

18. A device according to claim 1, wherein lateral roller guides (30) are provided to absorb the axial forces acting on the milling cutter (5).

19. A device according to claim 1, wherein milling cutter (5) used at least for the top surface of the slab is a face cutter (36).

20. A device according to claim 19, wherein several face cutters (36) are provided, which, when viewed in the transport direction (F), are arranged to overlap.

21. A device according to claim 19, wherein the face cutter (36) comprises a number of cutting edges (37), which can be cooled by a cutting edge cooling system (39).

22. A device according to claim 1, wherein a transfer table (40) is provided, which is designed so that the slab (3) can rest on it in the area of the milling cutter or cutters (5).

23. A device according to claim 22, wherein the transfer table (40) is designed with internal cooling.

24. A device according to claim 1, wherein the chip conveying device (6) is designed as a screw-shaped receiving element (54).

25. A device according to claim 24, wherein a guide element (15) is provided, which is designed to convey chips from the top surface of the slab into the receiving element (54) designed with a screw-like shape.

26. A device according to claim 24, wherein a deflecting plate (52) is provided, where the deflecting plate (52) can be sprayed with a jet of transport water discharged from a nozzle bar (49).

27. A device according to claim 1, wherein a guide channel is provided, through which the chips are drawn by suction from the top surface of the slab directly behind the milling gap, where the chips are transported away through a pipe transverse to the transport direction (F).

28. A device according to claim 1, wherein at least one magnet is set up, by means of which the chips can be influenced as they are being carried away.