EP3504352B1 - Method and apparatus for coating a metal sheet - Google Patents

Description

The invention relates to a method for coating a metal strip with the aid of a coating device. Inside the coating device, the belt first passes through a coating container with a liquid coating agent, e.g. B. zinc, and subsequently a stripping nozzle device for stripping excess zinc from the surface of the metal strip. After the stripping nozzle device, the belt typically passes through a belt stabilization device with a plurality of magnets on both broad sides of the belt.

In hot-dip galvanizing lines from the prior art, the zinc layer thicknesses vary both over the length and over the width of the strip. The layer thickness can change by up to 10 g per m ² . Since minimum layer thicknesses must be guaranteed, the average layer thickness must be adjustable so that all areas of the strip are above the limit. In order to reduce zinc consumption, there is a desire to keep the fluctuation range as small as possible.

The European patent specification also pursues this goal EP 1 794 339 B1 . In order to achieve a uniform zinc coating over the strip width and length, the European patent specification preferably uses a coordinated layer thickness-strip vibration, strip shape and strip positioning control. The vibration control, also called the belt stabilization device, dampens the vibrations of the belt. It comprises magnet pairs, which are preferably arranged in pairs over the bandwidth and are used as actuators for positioning the band. Each pair of magnets is preferably with a sensor for distance measurement and a controller equipped so that a force that varies across the bandwidth is exerted on the belt as a function of the forms of vibration that occur. In addition, the belt shape and belt position controller dampens the slow movements of the belt by changing the average force that acts on the belt across the belt. Each pair of magnets is controlled individually, in particular electrically, with the aid of the controller. The individual controllers are coordinated with the help of a higher-level controller, which takes into account the interactions between the controllers. In a preferred embodiment, the position of at least one magnet can be changed such that its distance from the band can be changed. The closer the magnet is to the tape, the less current or electrical energy is required to exert a desired force on the tape. At the beginning of a coating process, when the vibration amplitude of the strip is still relatively large, a greater distance between the magnets and the strip is required than in a steady state of the coating process, in which the amplitude of the vibrations of the strip is lower.

In the opposite arrangement of the magnets known from the European patent specification, basically only pure tensile forces are exerted on the tape. Due to these pure tensile forces, variations in the belt position, i. H. Changes in the actual position of the tape in both directions across the tape can be made. As already mentioned, belt movements and the actual position of the belt can be influenced well in this way.

However, around band curvatures such. B. to compensate for a U, S or W shape, a moment must be exerted on the tape. This is done according to the EP 1 794 339 B1 in that the higher-level coordinated controller also takes into account the couplings between the individual lower-level control loops that are assigned to the individual magnets. In other words, the force effects between adjacent coils or pairs of coils can be taken into account in this way. Force and distance create a moment and a counterbend can thus be produced in the undulating band, which preferably counteracts the existing curvature of the band. document WO2016 / 078803 A discloses a method and an apparatus for coating a metal strip, the metal strip continuing after the wiping nozzle device through an electromagnetic stabilization device in order to keep the fluctuation range of the strip small. The same subject is in the documents JPH 1029827 A and WO2009 / 039949 A disclosed.

The object of the invention is to provide an alternative possibility for generating a moment in the strip in a known method and a coating device for coating a strip.

This object is achieved by the method claimed in claim 1. This method is characterized in that the control of the magnets of the belt stabilization device takes place in that at least one of the magnets, depending on the shape-control difference in the width direction of the belt, is displaced relative to at least one of the magnets on the opposite broad side of the belt and shifted into a travel position , where it faces at least approximately a trough in the actual shape of the tape.

Thus, according to the invention, the paired arrangement of the individual magnets known from the prior art in opposition to each other on both broad sides of the band is dissolved and the individual magnets of a (former) pair of magnets are arranged offset to one another in the width direction of the band. While the opposing forces of the two magnets act in a line and therefore do not generate any torque when the magnets are compared in pairs, the inventive offset of the individual coils of the (former) magnet pair in the width direction causes a distance between the forces acting in opposite directions, as a result of which a desired Moment in or on the tape is generated. In this way the counter-bending results and therefore wavy bands can be smoothed and converted into a flat band.

The terms "band" and "metal band" are used interchangeably.
The term "shift in the width direction" includes any movement of the magnet in space as long as the movement has a component in the width direction of the metal strip.

The term "downstream" means: in the direction of transport of the metal strip. Conversely, "upstream" means against the direction of transport of the metal strip.

According to a first exemplary embodiment, in addition to the actual shape, the actual position of the strip can also be determined within the scraper nozzle device. In addition to the shape / control difference, a position / control difference can also be determined as the difference between the actual position of the strip and a predetermined target The position of the strip in the area of the stripping nozzle device can be determined, and the displacement of the at least one magnet in the width direction of the strip relative to the magnets on the opposite broad side of the strip can also take place as a function of the positional control difference so that the strip is in its actual position is transferred to the specified target position.

According to a further exemplary embodiment, a magnet pair or a plurality of magnet pairs are arranged in a stationary manner symmetrically with respect to the center of the slot of the band stabilization device or the band - viewed in the width direction, the two magnets each facing one another on both broad sides of the band. In the event that only one stationary pair of magnets is provided, the term symmetrical means that the pair of magnets is arranged in the middle. The stationary magnet pair or the stationary magnet pairs form a reference position. Relative to the at least one stationary pair of magnets, according to the invention at least some of the magnets adjacent to the stationary pair of magnets can be displaced or moved in the width direction of the band.

In particular, two further magnets, which form a pair of magnets, can be shifted into the area of the left or right edge of the band in such a way that the magnet of this pair of magnets which is at a greater distance from the edge of the band is centered on the height of the edge and that the magnet of the magnet pair that the has a smaller distance to the edge of the band, - compared to the magnet with the greater distance to the edge of the band - a bit to the center of the metal band - seen in the width direction - is arranged offset. This procedure is recommended for both the left and the right edge of the metal band. In this described procedure, too, the juxtaposition of the two individual magnets of the magnet pair is resolved by displacing them relative to one another in the width direction. The procedure described is particularly recommended, as I said, for the edge areas of the metal band, because the band curvatures, which often vary greatly there, can often not be adequately compensated for with the traditionally opposed magnets of a magnet pair or with the force effect between adjacent magnet pairs. For this special application, the offset according to the invention of individual magnets of a pair of magnets in the width direction relative to one another is considerably more effective.

Generally speaking, at least some of the magnets are moved in the width direction of the belt so that they are at least approximately opposite a trough of the actual shape of the belt. In this arrangement, oppositely directed tensile forces act on the metal strip at a distance from one another and thus generate a desired bending moment for reducing the curvatures or waveform in the strip.

The term "wave trough" describes the situation that the difference between the distance of a magnet to the metal strip in its actual shape and the distance of the magnet to the metal strip in its target shape - assuming the same position of the metal strip in each case - is greater than zero, in particular is maximum. This means that the distance between the magnet and the metal strip is larger in the case of a wave trough than if the metal strip were to have its desired shape. The trough can then be applied by a tensile force exerted by the magnet or "bulged" onto the metal strip by a bending moment applied by at least two magnets.

It should be noted that the magnets can only exert tensile forces, no compressive forces on the metal strip.

In the case of symmetrical, wave-like actual shapes of the band, it is advisable to move the magnets symmetrically in the width direction to the center of the band.

The magnets can be moved in the width direction depending on the number of magnets available. With a larger number of magnets available, a finer resolution of the force acting on the tape is possible, whereby the waveform can be even more precisely balanced.

The magnets can also be shifted in the width direction depending on the force that can be generated by the individual magnets on the belt. This lends itself to the background that the moment generated in the tape is the product of strength and distance. Against this background, a certain desired magnitude of the moment can be generated by an optionally suitable setting of either the generated force or the distance of the magnets from one another or from both.

The magnets are advantageously designed in the form of electromagnetic coils because the coils allow the force on the metal strip to be set in a variable manner as a function of the current fed in. In addition to influencing the position and shape of the tape as claimed by the invention by suitable displacement of individual magnets in the width direction of the tape, the position and shape of the magnets can also be carried out by suitably applying or supplying the coils with suitable currents. Specifically, according to the invention, at least one of the coils is fed with such a current that the tape is due to the current-carrying coil acting on the band force is transferred to its target position in the middle of the stripping nozzle device and is stabilized there and / or that the actual shape of the band is adapted as well as possible to the target shape.

In addition to the displacement of individual magnets according to the invention in the width direction of the strip and the said possibility of selecting suitable currents for the coils, the positioning and adjustment of the correction roller also offer a further possibility of influencing the shape and the position of the metal strip in the stripping nozzle device. Specifically, it is claimed according to the invention that the correction roller is positioned and adjusted upstream of the scraper nozzle device in such a way that it is ensured that the belt stabilization device is only operated within its operating limits. In other words, by means of a suitable positioning and adjustment of the correction roller, it is possible to preset the position and / or the shape of the metal strip in the slot of the scraper nozzle device so that there is only so little need for correction with regard to the shape and / or position of the metal strip, that the magnets in the band stabilization device do not have to be operated with currents outside their operating limits in order to implement the correction. The remaining need for correction to adapt the actual position to the desired position and / or to adapt the actual shape of the strip to its desired shape is then carried out according to the invention by suitable displacement of individual magnets in the width direction and by feeding these magnets with one each suitable current.

The correction roller can be moved appropriately not only before moving the magnets, but also during an ongoing coating process - as described in the previous paragraph. The correction roller can not only be positioned and adjusted to preset the position and shape of the belt. Rather, the correction roller can also be automatically positioned and adjusted so that when the predetermined force limits are exceeded the band in the band stabilization device the forces are again in a target area. This is particularly necessary when changing products, ie when changing to strips with different thicknesses or different materials with different yield strengths. The correction roller can also be automatically moved so that there are defined directions of action of the forces on the magnets to ensure unilateral or monotonous force application.

Figur 1

eine Beschichtungseinrichtung;

Figur 2

bekannte Ist-Formen und eine bekannte Soll-Form des Bandes;

Figur 3

bekannte Ist- und Soll-Lagen des Bandes; und

Figur 4

ein erfindungsgemäßes Verfahren von Magneten in Breitenrichtung des Bandes

veranschaulicht.Finally, it is provided that the travel positions of the magnets in the width direction, the currents with which the coils are acted upon and / or the position and the position of the correction roller are stored in a database. The storage is preferably classified according to the type of steel of the strip, the yield strength of the strip, the thickness of the strip, the width of the strip, the temperature of the strip as it passes through the coating device and / or according to the temperature of the coating agent in the coating container as it passes through the strip . By storing this data, better starting values can be determined in future coating processes, in particular by the travel positions of the magnets in the width direction of the new strips to be coated.
The above object is further achieved by a coating device according to claims 19 to 23. The advantages of this coating device correspond to the advantages mentioned above with reference to the method according to the invention.
Further advantageous embodiments of the method according to the invention are the subject of the dependent claims.
The description is accompanied by four figures

Figure 1

a coating device;

Figure 2

known actual shapes and a known target shape of the tape;

Figure 3

known actual and target positions of the tape; and

Figure 4

an inventive method of magnets in the width direction of the tape

illustrated.

The coating device according to the invention and the method according to the invention are described in detail below with reference to the figures mentioned in the form of exemplary embodiments. In all figures, the same technical elements are denoted by the same reference symbols.

Figure 1 shows a coating device 100 for coating a metal strip 200. The coating device 100 consists of a coating container 110 which is coated with liquid coating agent 112, e.g. B. zinc is filled. The metal strip 200 dips into the coating container and is deflected there in the liquid coating agent with the aid of a pot roller 150. The metal strip 200 is then guided past a correction roller 140 and subsequently through the slot of a wiping nozzle device 120 and further subsequently through the slot of a belt stabilization device 130. An air stream is preferably applied to the strip on both sides within the stripping nozzle device 120 in order to scrape off excess liquid coating agent.

The band stabilization device 130 consists of a plurality of magnets 132 which are arranged on both broad sides of the band or the band stabilization device. These magnets are 132 typically in the form of electromagnetic coils. The coating device 100 further comprises a control device 160 for actuating an actuator 136 for displacing or moving the magnets 132 according to the invention in the width direction R of the strip and for setting the current I which is fed into the individual magnets. In addition, the control device can have an output for actuating an actuator 146 for positioning and adjusting the correction roller 140. The actuators 136, 146 are actuated and the current for the magnets is adjusted as a function of measurement signals from a distance sensor which traverses preferably in the width direction of the strip. The distance sensor detects the distribution of the distance of the metal strip in the width direction with respect to a reference position, e.g. B. the gap or slit of the band stabilization device. In this way, both the actual shape and / or the actual position of the metal strip is recorded. Alternatively, a separate shape sensor 170 for detecting the actual shape of the strip and a separate position sensor 180 for detecting the actual position of the metal strip can also be provided.

The actual position and / or the actual shape of the metal strip within the stripping nozzle device 120 is determined by measuring the position and / or the shape of the strip either between the stripping nozzle device 120 and the strip stabilizing device 130 or within the strip stabilizing device 130 or upstream of the strip stabilizing device 130 and by subsequently concluding from the actual position and / or the actual shape of the band within the stripping nozzle device from the respectively measured position and / or form of the band. The actual position and / or the actual shape of the band within the band stabilization device 130 is determined by measuring the distance of the band from the magnets of the band stabilization device across the width of the band.

Figure 2 shows various examples of possible undesirable actual shapes of the metal strip 200, specifically a U, an S and a W-shaped metal strip. In the lower area shows Figure 2 on the other hand, the desired target shape of the metal strip 200. Accordingly, the metal strip is straight or flat in its target state.

Figure 3 shows various undesired actual positions of the metal strip 200 in the slot 122 of the scraper nozzle device 120. The various actual positions are shown in broken lines, while the desired position SL is shown with a solid line. Specifically, the target position is characterized in that the metal strip 200 is evenly spaced from the sides of the slot 122. In contrast, the metal strip can be rotated or pivoted by an angle α in a first undesired actual position I1 relative to the target position SL. A second undesired actual position of the metal strip I2 of the metal strip is that the metal strip is displaced in parallel with respect to the desired position SL, so that the metal strip no longer has the same distances from the broad sides of the slot. Finally, a third typical undesirable actual position for the metal strip is that the metal strip is shifted in the longitudinal direction according to position I3 with respect to the desired position SL, so that its distances from the narrow sides of the slot 122 of the stripping device are no longer the same.

Figure 4 illustrates the method according to the invention. After determining the actual shape of the band 200 within the scraper nozzle device 120 across the width of the band z. B. in the form of in Figure 2 Types shown above, the actual shape with a predetermined target shape of the tape, typically as in Figure 2 shown below. The deviations in the shape form a shape-control difference and the magnets 132 of the strap stabilization device 130 are controlled depending on the shape-control difference in such a way that the actual shape of the strap is converted into the desired shape of the strap. According to the invention, at least some of the magnets 132 in the width direction R of the Band 200 shifted relative to the magnets on the opposite broad side of the band in a travel position. These travel positions are in Figure 4 shown as an example.

In addition to the actual shape, the actual position of the strip 200 within the stripping nozzle device 120 can also be determined. Undesirable manifestations of this actual situation have already been referred to above Figure 3 presented. In addition to the shape-control difference, a position-control difference can also be determined analogously as the difference between the actual position of the belt and a predetermined target position SL in the area of the wiper nozzle device 120. The displacement of the at least one magnet 132-A in the width direction R of the band 200 relative to the magnets 132-B on the opposite broad side of the band 200 can accordingly also take place as a function of the positional control difference so that the band is in its actual position in the specified target position SL is transferred.

In general, it makes sense that at least some of the current-carrying magnets, ie the active magnets 132, are moved in the width direction R of the belt 200 in such a way that their travel position, also called the end position, is at least approximately opposite a trough in the actual shape of the belt 200, like this in Figure 4 is illustrated. The advantage of this procedure is that the forces of the individual spool acting in different directions then act at a distance from one another and thus a torque or bending moment can be generated on the band 200 in order to compensate in particular for transverse curvatures or undesired waveforms. The bending moments generated by the forces F of the coils are in Figure 4 designated by the reference symbol M.

Figure 4 shows a special embodiment for possible travel positions. Specifically, in this embodiment - seen in the width direction R - in the middle of the band 200 a pair of magnets 132-3-A; 132-3-B stationary arranged. The two magnets of this pair of magnets face each other on both broad sides A, B of the band 200. In contrast, the other coils or magnets are not arranged in the form of magnet pairs, the individual magnets 132-1, -2, -4, -5 are directly opposite one another. These remaining magnets are displaced or offset in the width direction R of the band relative to magnets on the other side of the band.

Specifically, two further magnets 132-1-A and 132-1-B form a left magnet pair, which is displaced into the area of the left edge of the band 200 in such a way that the magnet 132-1-B of the left magnet pair, which has the greater distance d _I1 to the edge of the band has its center displaced at the level of the left edge and that that magnet 132-1-A of the left pair of magnets which has the smaller distance d _I2 to the left edge of the band is opposite the magnet 132 -1-B with the greater distance d _I1 to the edge of the band - a piece to the fixed magnet pair 132-3-A, 132-3-B, ie is offset to the middle of the band. Due to the staggered arrangement of the two partial coils 132-1-A and 132-1-B of the left pair of coils, this is in Figure 4 shown torque exerted counterclockwise on the left edge region of the band 200, whereby the transverse curvature there can be eliminated.

Alternatively or additionally, a right pair of magnets 132-5-A, 132-5-B can be provided, which is displaced into the area of the right edge of the band 200 in such a way that its partial magnet 132-5-B, which has the greater distance d _r1 has shifted to the right edge of the band 200 with its center at the level of the right edge. Furthermore, the partial magnet 132-5-A of the right pair of magnets, which has the smaller distance d _r2 from the right edge of the band, becomes a bit towards the center of the band 200 compared to the magnet with the greater distance from the edge of the band transferred. In this case, the in Figure 4 tensile forces F generated by the partial coils, which act on the band 200 at a spacing from one another Bending moment M clockwise on the band 200. This allows the in Figure 4 still shown waveform can be compensated on the right edge.

The remaining magnets 132-2-A, 132-2-B, 132-4-A and 132-4-B, which do not belong to either the right, left or middle pair of magnets, are preferably so in the width direction R of band 200 procedure that they are each at least approximately opposite a trough in the actual shape of the tape, as shown in Figure 4 is shown and by which the advantageous effect described above is achieved by generating the bending moments.

As also in Figure 4 is recognizable, results in particular in the case of a symmetrical undesired actual shape of the band when the magnets are displaced in the width direction Figure 4 shown symmetrical arrangement of the magnets, in particular the symmetrical arrangement with respect to the fixed magnet pair 132-3-A, 132-3-B.

Reference symbol list

100

Coating facility

110

Coating container

112

Coating agent

120

Scraper nozzle device

122

Scraper nozzle slot

130

Belt stabilization device

132

Magnets

136

Actuator

140

Correction role

150

Pot roll

160

Control device

170

Shape sensor

180

Position sensor

200

Metal strap

d _l1

distance

d _l2

distance

d _r1

distance

d _r2

distance

F

force

I1

Inclination

I2

Parallel shift

I3

Offset

M

Bending moment

R

Width direction

SL

Target position

α

angle

Claims (23)

1. A method for coating a metal strip (200) with the help of a coating device (100), in which the strip (200) is guided through a coating container (110) with a liquid coating agent (112), subsequently through the slot of a stripping nozzle device (120) and then subsequently through the slot of a strip stabilizing device (130) with a plurality of magnets (132) on the two broad sides of the strip, including the following steps:

   determining the actual shape of the strip (200) within the stripping nozzle device (120) over the width of the strip;

   determining a shape control deviation as the difference between the actual shape of the strip (200) and a predetermined setpoint shape of the strip in the area of the stripping nozzle device (120); and

   controlling the magnets (132) of the strip stabilization device as actuators so that the actual shape of the strip (200) is transformed into the setpoint shape of the strip;

   characterized in that

   the controlling of the magnets of the strip stabilization device occurs by shifting at least one of the magnets (132-A) as a function of the shape control deviation in the width direction (R) of the strip (200) relative to at least one of the magnets (132-B) on the opposite broad side of the strip and moving the same into a processing position in which it is at least approximately opposite a trough in the actual shape of the strip.
2. The method according to claim 1,
   characterized in that,
   in addition to the actual shape, the actual position of the strip (200) inside the stripping nozzle device (120) is also determined;
   in that, in addition to the shape control deviation, a position control deviation is also determined as the difference between the actual position of the strip and a predetermined setpoint position of the strip (200) in the area of the stripping nozzle device (120); and
   in that the movement of the at least one magnet (132-A) in the width direction (R) of the strip (200) relative to the magnets (132-B) on the opposite broad side of the strip (200) also occurs as a function of the position control deviation so that the strip is conveyed from its actual position to its predetermined setpoint position.
3. The method according to one of the preceding claims,
   characterized in that,

   - viewed in the width direction - a magnet pair or a plurality of magnet pairs (132-3-A; 132-3-B) are arranged in a stationary manner symmetrically in relation to the centre of the slot of the strip stabilization device (130) or of the strip (200), wherein the two magnets of a magnet pair are respectively arranged on the two broad sides (A, B) of the strip opposite one another; and
   in that at least some of the magnets (132-1, -2, -4, - 5) adjacent to the at least one stationary magnet pair are moved in relation to the stationary magnet pair in the width direction (R) of the strip (200) so that, in their processing position, they are at least approximately opposite a trough in the actual shape of the strip.
4. The method according to one of the preceding claims,
   characterized in that
   the movement of the at least one magnet in the width direction (R) occurs symmetrically in relation to the centre of the strip.
5. The method according to one of the preceding claims,
   characterized in that
   two further magnets (132-1-A; 132-1-B) form a left magnet pair, which is moved into the area of the left edge of the strip so that the magnet (132-1-B) of the left magnet pair which is at a greater distance (d_l1) from the edge of the strip is moved with its centre to the height of the left edge, and in that the magnet (132-1-A) of the left magnet pair which is at a smaller distance (d_l2) from the left edge of the strip (200) - viewed in the width direction - is arranged so as to be offset in relation to the centre of the metal strip so that it is at least approximately opposite a trough in the actual shape of the strip;
   and/or
   in that still two further magnets (132-5-A; 132-5-B) form a right magnet pair, which is moved into the area of the right edge of the strip (200) so that the magnet (132-5-B) of the right magnet pair which is at a greater distance (d_r1) from the edge of the strip (200) is moved with its centre to the height of the right edge, and in that the magnet (132-5-A) of the right magnet pair which is at a smaller distance (d_r2) from the right edge of the strip - viewed in the width direction - is arranged so as to be offset in relation to the centre of the metal strip so that it is at least approximately opposite a trough in the actual shape of the strip.
6. The method according to claim 5,
   characterized in that
   the remaining magnets (132-2-A, 132-2-B, 132-4-A, 132-4-B) which do not belong to the right, left or centre magnet pair are moved in the width direction (R) of the strip (200) so that they are at least approximately opposite a trough in the actual shape of the strip.
7. The method according to one of the preceding claims,
   characterized in that
   the determination of the actual position and/or of the actual shape of the strip (200) occurs within the stripping nozzle device (120) by
   measuring the position and/or shape of the strip either between the stripping nozzle device (120) and the strip stabilization device (130), or within the strip stabilization device or downstream from the strip stabilization device; and by
   inferring the actual position and/or actual shape of the strip (200) within the stripping nozzle device (120) from the measured position and/or shape of the strip.
8. The method according claim 7,
   characterized in that
   the determination of the actual position and/or of the actual shape of the strip occurs within the strip stabilization device (130) by measuring the distance of the strip from the magnets of the strip stabilization device over the width of the strip.
9. The method according to one of the preceding claims,
   characterized in that
   the movement of the magnets in the width direction (R) additionally occurs as a function of the available number of magnets (132) on each of the broad sides of the strip.
10. The method according to one of the preceding claims,
    characterized in that
    the movement of the magnets (132) in the width direction (R) occurs as a function of the force (F) acting on the strip (200) that can be generated by the individual magnets.
11. The method according to one of the preceding claims,
    characterized in that
    the magnets (132) are configured in the shape of electromagnetic coils.
12. The method according to claim 11,
    characterized in that
    at least one of the coils is fed with such a current that the strip is conveyed as a result of the force (F) acting on the strip through the active coil into its setpoint position in the centre of the stripping nozzle device (120) and is stabilized there and/or in that the actual shape of the strip is adapted as optimally as possible to the setpoint shape.
13. The method according to one of the preceding claims,
    characterized in that
    a correcting roller (140) is positioned and engaged upstream from the stripping nozzle device so that the strip stabilization device and in particular its magnets can be operated within their operating limits.
14. The method according to one of the preceding claims,
    characterized in that
    the actual shape of the strip (200) designates, for example, an S- or U- or W-shaped cross-section of the strip.
15. The method according to one of the preceding claims,
    characterized in that
    the setpoint shape of the strip (200) designates a rectangular cross-section or the evenness of the strip.
16. The method according to one of the preceding claims,
    characterized in that
    the actual position of the strip (200) designates, for example, an inclined position (11) or a translation (12) or an offset (13) of the strip (200) in relation to the setpoint position (SL) in the slot (122) of the stripping nozzle device (120).
17. The method according to one of the preceding claims,
    characterized in that
    the setpoint position (SL) of the strip designates the centred position in the slot (122) of the stripping nozzle device (120).
18. The method according to one of the preceding claims,
    characterized in that
    the processing positions of the magnets in the width direction (R), the currents applied to the coils and/or the position and engagement of the correcting roller (140) are saved in a database, preferably classified according to the steel grade of the strip (200), the yield strength of the strip, the thickness of the strip, the width of the strip, the temperature of the strip and/or according to the temperature of the coating agent (112) in the coating container (110) when the strip (200) is run through it.
19. A coating device (100) for coating a metal strip with a coating agent (110), for example zinc, having:

    a coating container (110), which is filled with the liquid coating agent;

    a stripping nozzle device (120);

    a strip stabilization device (130) with a plurality of magnets (132) on the two broad sides of a slot of the strip stabilization device;

    at least one sensor (170, 180) for the capture of the actual shape and/or of the actual position of the metal strip in the slot of the stripping nozzle device (120); and

    a control device (160) for determining a shape control deviation as the difference between the actual shape of the strip (200) and a predetermined setpoint shape of the strip in the area of the stripping nozzle device (120) and for controlling the magnets (132) via a magnet actuator (136);

    characterized in that

    the control device and the magnet actuator (136) are further configured so as to shift as a function of the shape control deviation at least one of the magnets in the width direction of the strip relative to at least one of the magnets on the opposite broad side of the strip and move the same into a processing position in which it is approximately opposite a trough in the actual shape of the strip.
20. The coating device (100) according to claim 19,
    characterized in that
    the control device (160) and the magnet actuator (136) are further configured to move also the at least one magnet (132) as a function of the position control deviation of the strip (200) in the width direction.
21. The coating device (100) according to claim 19 or 20,
    characterized in that
    the control device (160) is further configured to also control the actuator (146) of the controlling roller (140) in such a manner that the strip stabilization device is operable within its operating limits.
22. The coating device (100) according to one of claims 19 to 21,
    characterized in that
    the control device (160) is further configured to set the current (1) through the at least one magnet (132) as a function of the actual shape and/or of the actual position of the strip (200) so that the setpoint shape and/or the setpoint position are ideally realized.
23. The coating device (100) according to one of claims 19 to 22,
    characterized in that
    the number of magnets (132) per broad side is uneven, for example 5 or 7.

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