JP2008546908A - Apparatus and method for guiding metal strips in continuous processing equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device for guiding a metal strip in a non-contact manner.
SOLUTION: Two sets of magnetic poles perpendicular to a metal strip are provided, and magnetic field lines (zones A1, A2) for applying a repulsive force to the metal strip are formed in the vicinity of the magnetic pole, and the metal strip travels between the magnetic field lines. An apparatus and a method for guiding a metal strip in a continuous processing apparatus in which an area is provided and a force for returning the metal strip to the original traveling area is generated when the metal strip is displaced from a predetermined traveling area (zone B).
[Selection] Figure 3

Description

  The present invention relates to a device for non-contact guidance of a metal strip over the length of a strip that extends freely between two mechanical support means, both magnetic and non-magnetic, which strips It extends continuously over this length through a passage window between the avoiding walls or elements.

  The present invention provides for a continuously movable metal strip that extends continuously, whether magnetic or non-magnetic, such as heat treatment lines, metal or organic coating lines, or conditioning lines, for example to cut or cut to appropriate lengths. For any equipment.

  In a continuous metal strip processing line, the process performed requires that the metal strip be positioned corresponding to the various aspects of the equipment required for each step of the process. This positioning is usually done using rollers to ensure each stage of the process, which carries the metal strip, guides it and positions it as close to the theoretical plane as possible. Usually, the metal strip is positioned in a horizontal or vertical plane.

  For certain treatments, for example, treatments for the coating of metal coatings (especially for galvanizing) or organic coatings (especially for paint coatings), or products with a surface sensitive to scratches, or in contact with another surface For the treatment of local degradation of the surface coating due to this, it is not possible to attach a roller to the processing zone as it will leave traces on the coating that will be unacceptable defects in the final product.

  Thus, the metal strip is kept in the correct position over the entire free length of its treatment zone and is affected by its own weight, the influence of the forces produced by the treatment, or for other reasons, the metal strip being one of the treatment equipment walls. It is necessary to employ a non-contact guide device to prevent touching one.

Furthermore, it is necessary to prevent the metal strip from vibrating.
The lack of an effective device for non-contact guidance of the metal strip in a continuous metal strip processing line, for example, reduction of the length for possible processing between two rollers for mechanical support, Limits are imposed on the process, such as rate limiting or reducing the thickness of the deposited film.

  To overcome these difficulties, a variety of applications such as mounting a low-contact intermediate support such as a roller that applies lower pressure to the product, or using special materials such as carbon or ceramic in the contact zone A solution has already been envisaged. These measures have proved inadequate because there is a risk of scarring from contact and / or whatever the support material is soiled and / or defective.

  Non-contact guide devices that basically use gas jet nozzles to construct pneumatic means for supporting the metal strip were also envisaged. The effectiveness of the system is not completely satisfactory, especially in coating lines where spraying through the nozzles can interfere with coating deposition, solidification or drying. is not. Moreover, the instrument used to coat the surface of the metal strip can be deposited in solid, liquid or gas phase on the nozzle orifice, reducing the cross section and making it inoperable.

  Electromagnetic levitation systems are also known, particularly those shown in FR 2 521 797 and FR 2 598 866. In the electromagnetic levitation system, the magnetic poles perpendicular to the metal strip typically generate an electromagnetic field on each side of the metal strip, with the alternating current flowing through the coil partially passing through the metal strip and looping back to the magnetic yoke. Set to produce. The poles located facing each other are of the same type, either north and north or south and south, and the resulting magnetic repulsion creates a suspension effect on the metal strip. The magnetic levitation system is a power source induced in the metal strip, which does not cause insignificant additional heating.

  The object of the present invention is to provide a device for non-contact guidance of a metal strip, whether magnetic or non-magnetic, and in particular it is envisaged to guide the length between two mechanical support means. For application, the device uses several sets of magnetic poles while overcoming the above difficulties and without incidentally causing significant additional heating.

The device for non-contact guidance of a metal strip over the length of a metal strip that extends freely between two mechanical support means, whether magnetic or non-magnetic, according to the invention, is a wall where the metal strip avoids contact. Or two sets of magnetic poles extending continuously through this length through a passage window between the elements, but at least in a specific zone of said length, perpendicular to the metal strip, One set is placed on each side of the metal strip, the poles of the metal strip are equipped with a coil supplied with an alternating current of the appropriate frequency, and one set of poles is another set located on the opposite side of the metal strip. The frequency of the alternating current flowing through the magnetic strip, the magnetic pole spacing, the coil and the coil is placed in the passage window through which the metal strip extends, Characterized in that it is selected to produce a three zone serial.
-Two zones where most of the magnetic field lines that are proximate to each pole and go from one pole to the opposite polarity pole in the same set,
-Central zone where the relevant magnetic field lines do not pass in part.

  The metal strip is usually in this central zone where it is not subject to easily sensed electromagnetic effects, but when the metal strip deviates from the central zone and enters one of the zones close to the pole, the metal strip is there In response to the electromagnetic repulsion directed to the central zone, this repulsion is higher the closer the pole is to the pole, without causing substantial additional heating, if the metal strip has no walls or walls defining the passage window, Therefore, guidance is accompanied.

Usually, the width of the passage window is greater than 30 mm, but preferably less than 500 mm.
The frequency of the alternating current flowing through the coil is adapted not only to the desired repulsive force, but also to the material that forms the heat shield between the pole and the metal strip.

  The frequency is very low in terms of electrical (generated) heat shielding (property) and its thickness (eg, stainless steel shielded thickness is small, eg 1 mm to 3 mm) 1 Hz to 30 Hz.

  From the viewpoint of shielding the heat generated by the magnetic flux [property], the frequency is 30 Hz or higher, and is preferably equal to or higher than 1500 Hz.

  The guide device can include an isolation enclosure that passes the magnetic flux and is placed between the surrounding metal strip and the wound magnetic pole. The isolation enclosure may be gas resistant and ensures isolation between the air in the process equipment and the outside so as to confine the internal air. This isolation enclosure can enclose a liquid bath in other applications.

  The arrangement of the network of poles ensures that the effect optimizes the holding of the metal strip in place at the end of the metal strip, or in the center thereof.

  The magnetic repulsion of the magnetic pole is adapted to the width of the metal strip depending on the position of the metal strip or the effect imparted thereto.

  Advantageously, the device includes means sensitive to, for example, magnetic coupling between the metal strip and the electromagnetic pair, this magnetic coupling appearing upon entry of the metal strip into a zone essentially close to the magnetic pole, This sensitive means is suitable for causing an increase in magnetic repulsion when this magnetic coupling is detected, in particular by increasing the magnitude of the alternating current in the coil.

  The metal strip may be vertical or horizontal. The metal strip is adapted to be subjected to mechanical tension between the mechanical support means.

  The means for blowing the gas can be inserted in the magnetic pole, either between the magnetic poles, or both.

  The invention also relates to a method for non-contact guidance of a metal strip over the length of a metal strip freely extending between two mechanical support means, whether magnetic or non-magnetic, in which method At least in a particular zone of the aforementioned length, an alternating magnetic field of suitable frequency is created on both sides of the metal strip.

  The method is such that the strength of the magnetic field and its frequency are in three zones in the passage window through which the metal strip extends, i.e., two zones where most of the magnetic field lines are deployed and substantially the corresponding magnetic field lines. Characterized by the fact that it is selected to create a central zone that does not pass through, the metal strip is usually in this central zone, where it is not subject to easily sensed electromagnetic effects, but the metal strip deviates from the central zone and is close to the pole When entering one of the zones, the metal strip receives an electromagnetic repulsion directed at the central zone.

The invention is not limited to the arrangement described above, but consists of many other arrangements which will be described in more detail below with reference to the exemplary embodiments illustrated with reference to the accompanying drawings, which embodiments are quite limited is not. These drawings are as follows.
FIG. 1 is a schematic illustration of a portion of a metal strip heat treatment line comprising a heated portion followed by a cooling portion.
FIG. 2 is a schematic view of a part of the galvanizing line, similar to FIG.
FIG. 3 is a cross-section at a larger scale of line III-III in FIG. 1, this cross-section being rotated by 90 °, illustrating a guide device according to the invention.
FIG. 4 is a cross section showing some possible positions of the metal strip, similar to FIG.
FIG. 5 is a cross section of an alternative embodiment, similar to FIG.
FIG. 6 is a simplified partial vertical section of a processing line with an electromagnetic guide device protected by a heat shield.
FIG. 7 shows an alternative embodiment, similar to FIG.
FIG. 8 shows another embodiment at a larger scale, similar to FIG.
FIG. 9 shows, in a vertical section, part of a processing line with an electromagnetic guiding device and a spray box.
FIG. 10 shows an alternative embodiment, similar to FIG.

  FIG. 1 shows part of a heat treatment line in which a metal strip 1 extends vertically over a free length L between mechanical support means consisting of a lowermost roller 2 and an uppermost roller 3 respectively. The length L is approximately 50 m or more. The metal strip 1 continues continuously over its length, for example downwards, from roller 3 to roller 2, through a passage window E between the line and / or the processing equipment wall. It extends. For example, the provided upstream is a heating zone C with a transverse flux heater 4 for heating the metal strip. One or more cooling boxes R follow the heating chamber, for example by blowing a cooling gas of a nitrogen-hydrogen mixture, while the metal strip 1 again opens a window surrounded by a blowing nozzle that the metal strip should not touch. pass. The metal strip 1 can be a steel strip.

  FIG. 2 shows that a metal strip 1a heated to the desired temperature passes through the periphery of the bottom roller 2a and is immersed in the molten zinc bath B. The metal strip then rises vertically, passes through the air knife and wiping machine E and then passes through the cooling box Ra, where cooling is achieved by blowing a relatively cool gas onto the metal strip la covered with the zinc layer. Provided.

  The metal strip 1 or 1a is under tension between the rollers 2, 3 or 2a, 3a, but can be subject to fluctuations perpendicular to the direction of travel, especially because of its large length L Sudden fluctuations can occur. Such lateral changes or deviations of the metal strip run the risk that the latter will come into contact with the walls or elements bounding the passage window E and thus damage the surface of the metal strip.

  In order to prevent the contact, the present invention provides a guide device G, which is also referred to as a “non-contact metal strip centering device” that uses electromagnetics.

  As shown in FIG. 3, a magnetic pole 5 through a winding 6 through which an alternating current of suitable frequency flows is placed on each side of the metal strip 1.

  The magnetic poles 5 form two sets P1, P2 located on each side of the metal strip 1. Each magnetic pole 5 of the first set P1 is located facing the same type of magnetic pole 5 as the other set P2. The pole spacing J (FIG. 3) corresponds to the distance between the two subsequent pole geometric axes. As shown in FIG. 3, two sets of north (N) and south (S) poles face each other on both sides of the metal strip 1. In a given set, several successive yokes 7 are provided, each with a magnetic pole N and a magnetic pole S. The magnetic field lines from magnetic pole N to magnetic pole S of every yoke are indicated by arrows 8 in FIG. 3 and enter and exit the magnetic poles 5 on their faces 9. These magnetic field lines 8 develop near the metal strip 1 and follow the return path of the magnetic yoke 7. The magnetic poles 5 are assigned along the transverse direction of the metal strip 1 and are placed according to the desired effect and geometrical arrangement of the metal strip ([reciprocal to each other]). The winding 6 is supplied with an alternating current of suitable size and frequency, for example continuously or individually. In FIG. 3, four yokes 7 are allocated on both sides of the metal strip 1 along the transverse direction. The magnetic pole 5 is also assigned along the longitudinal direction of the metal strip.

  The magnetic flux [generated by] heat [is] shielded [location] Q is provided on each side of the metal strip 1 between the latter and the magnetic pole 5. The width of the passage window corresponds to the distance D between the insides of the heat shield Q in FIG.

  The frequency of the magnetic pole 5, its magnetic pole spacing, the winding 6 and the alternating current flowing through the winding 6 is in the passage window so that most of the three zones A 1, B, A 2, ie the magnetic field and the magnetic field lines indicated by arrows 8, Two zones A1, A2 close to the developing magnetic pole are selected, as well as a central zone B in which the magnetic field is virtually zero, i.e. substantially no magnetic field lines 8 pass through this zone.

  As a non-limiting example, the thickness of each of zones A1 and A2 can be approximately 50 mm, while the thickness of zone B is approximately 100 mm, thereby giving the passage window a thickness of approximately 200 mm, It is perfectly compatible with the actual operating conditions of the process that this guide device is intended for, particularly with respect to the deformation of the metal strip 1 which is related to the manufacturing process.

The operation of the guide device is as follows.
When the metal strip 1 is completely in zone B, it experiences virtually no magnetic flux from the pole 5 and is not affected by any of the effects such as induced current, heating, force. Guidance is finally provided by the end rolls 2 and 3 at that time. Thus, when the metal strip occupies the normal operating position in zone B, the electromagnetic device is completely neutral per metal strip 1.

  If for some reason the metal strip 1 or part thereof moves to the zone A1 or A2, the metal strip or part thereof will pass the magnetic field lines 8 and cause the magnetic field of the magnetic pole located close to the corresponding zone. receive. The current induced in the metal strip reacts with the tangential component of the alternating magnetic field, which component is placed in the plane of the metal strip to create a repulsive force perpendicular to the metal strip according to Lorentz's law. These repulsive forces have the effect of moving the metal strip 1 away from the device, i.e. the wall 9 defining the shape of the pole end 9 or the passage window where the metal strip is likely to contact.

  What is obtained in this way is the desired effect of preventing contact between the metal strip 1 and the walls of the equipment or processing equipment.

  By adjusting the dimensions of the magnetic pole 5, the magnetic pole spacing, the position of the magnetic pole relative to the metal strip, the characteristics of the winding 6, the frequency and current of the source, the size of some of these parameters or just one of them It is possible to control the repulsion experienced by the strip 1. In this way, the effect of the guiding device on the continuous process performed on the metal strip 1 can be controlled. These adjustments can also select the dimensions of zones A1, B and A2 to suit the process.

  The geometry of the magnetic poles 5 facing the metal strip 1 is also varied, i.e. the magnetic pole spacing selectively protects the edges of the metal strip, for example, so that the end result of the effect is the center of the metal strip. It is adjusted differently at the edges.

  FIG. 4 illustrates two examples of possible movements of the metal strip 1, indicated by a solid line as the moved first position 10 and indicated by a dashed line as the second position 11.

  When the metal strip 1 is moved to position 10 in zone A1, it experiences a repulsive force across the entire width through the movement of the pole set so that it is pulled back to zone B substantially parallel to itself.

  When the metal strip 1 occupies a position 11 corresponding to the torsion of the magnetic holding part, the part located in the zones A1 and A2 experiences a repulsive force in the opposite direction, which resists torsion of the metal strip and for the metal strip 1 Create a return moment that tends to return it to Zone B corresponding to the desired theoretical plane.

  The deeper the metal strip 1 penetrates into zone A1 or A2, the higher the repulsive force acting on this metal strip in order to get closer to the magnetic pole and return it to zone B. The metal strip is returned from zone A1 or A2 to zone B without the risk of touching the wall and thus causing no surface flaws on the metal strip 1.

  FIG. 5 shows an alternative embodiment in which the cross section of the metal strip 1 is separated from the magnetic pole 5 by a closed diagonally transverse contour, for example a rectangular contoured envelope 12, which passes the magnetic flux. The enclosure 12 is thin enough that it does not interfere with the operation of the device and makes it possible to employ repulsion zones A1 and A2 sufficient to ensure a particularly satisfactory operation of the device. The enclosure 12 makes it possible to separate the internal atmosphere in which the metal strip 1 extends from the atmosphere in which the magnetic poles 5 are present.

  FIG. 6 is a vertical cross-sectional view that schematically illustrates the attachment of the enclosure 12 and is mechanically connected by flanges 12a to the upstream and downstream walls of the processing line.

  As illustrated in FIG. 7, the material Ma made of resin or concrete can withstand the impacts likely due to the use of the guide device and to make a panel compatible with the chemical properties of the gases used in the process. By enclosing the winding 6 and the magnetic pole 5, results similar to those of FIGS. 5 and 6 are obtained. The two panels located on both sides of the metal strip are connected to make a gas resistant enclosure. The guide device then becomes one centering device that is housed in a box that is secured to the upstream and downstream walls of the line.

  This arrangement ensures the continuity of the atmosphere in the upstream and downstream zones of the guiding device, for example an atmosphere consisting of hydrogen or ammonia in the case of heat treatment, or an atmosphere containing organic solvent vapor in the coating line, etc. It is possible to prevent leakage of gas that is dangerous to the operator or the environment.

  The gas resistant enclosure 12 through which the magnetic flux passes is also cooled if the temperature associated with the process so requires.

  In FIGS. 8 to 10, only that part of the equipment located to the right of the metal strip is shown to simplify the situation. The part located on the left can be deduced from the right-hand part by being symmetrical with respect to the plane of the metal strip.

  FIG. 8 shows, in a vertical section, an alternative embodiment in which the magnetic guiding device G is housed in a box T that is made of sheet metal, for example, and is hermetically fixed upstream and downstream of the line. The heat shield Q is placed in the plane of the box opening, without sealing and closing it, towards the metal strip.

  Unlike guides using journal-supported rollers, which must pass through the furnace wall with the guide device according to the invention, the metal strip without communication between the inside and outside of the furnace 1 can be held at a predetermined position.

  Advantageously, the guiding device includes means 13 (FIG. 5) for detecting the entry of the metal strip 1 in zones A1 and A2, which in order to increase the repulsion of the magnetic force, Suitable for operating with control means 14 for increasing the magnetic field produced by the coil and the magnetic pole 5 concerned.

  The entry of the metal strip 1 into the zone A1 or A2 is detected by identifying the magnetic coupling of the magnetic pole 5 with the metal strip. For example, when the metal strip 1 enters zone A1 or zone A2, a detection means is provided that is sensitive to variations in the frequency of the current in the coil 6 produced by magnetic coupling.

  In particular, an increase in repulsion can be obtained by increasing the magnitude of the current flowing through the coil 6. However, increasing the frequency also promotes an increase in repulsion.

  Instead of being detected by magnetic coupling, the entry of the metal strip 1 into the zone A1 or A2 is sensitive to the entry of the metal strip 1 into the zone A1 or A2 and acts as a means to control the means of increasing repulsion. Alternatively, it could be detected by proximity sensors 15 and 16.

  Using means that are sensitive to the position of the metal strip and cause an increase in repulsion, the guide device becomes an active device and power is consumed when there is a metal strip in zone B, which power is consumed by the zone A1. Or it is increased only when entering A2. As a result, there is a considerable degree of energy saving and no undesirable heating of the metal strip.

  The guide device G can be used in combination with, for example, a cooling device including at least one box S (FIG. 9) for blowing cooling gas.

  As illustrated in FIG. 10, the magnetic pole 5 includes a groove 17 for injecting a cooling gas into the metal strip 1. It is also possible to place the gas injection nozzle 18 between the magnetic poles 5 along both the longitudinal and lateral directions of the metal strip. The blowing box Sa covers the yoke 7 on the opposite side from the metal strip 1. By these means, the centering device does not overload the furnace cooling zone.

The present invention can be employed in many applications such as the following.
-Hold the metal strip in place in the cooling tower of the galvanizing line, as schematically illustrated in Figure 2, without leaving scars on the zinc coating that has not yet solidified after the treatment bath.
-In the stainless steel bright annealing line to avoid contact with the surface of the metal strip which may cause scratches in the hot part of the process or in the mechanical part for introducing and pulling out the metal strip Hold the metal strip in place.
-The metal device of the present invention is easier to install than two rollers, or allows the chamber to be sealed against the gas used in the process under optimum conditions, so that the metal strip in the heat treatment line In place.

FIG. 1 is a schematic illustration of a portion of a metal strip heat treatment line comprising a heating portion followed by a cooling portion. FIG. 2 is a schematic explanatory diagram regarding a part of the galvanizing line, as in FIG. 1. FIG. 3 is a cross-sectional explanatory view at a larger scale taken along line III-III in FIG. FIG. 4 is a cross-sectional illustration showing several possible positions of the metal strip, similar to FIG. FIG. 5 is a cross-sectional illustration of an alternative embodiment, similar to FIG. FIG. 6 is a simplified partial vertical sectional view of a processing line with an electromagnetic guide device protected by a heat shield. FIG. 7, like FIG. 6, is a cross-sectional illustration showing an alternative embodiment. FIG. 8 is a cross-sectional explanatory view showing another embodiment at a larger scale, similarly to FIG. 6. FIG. 9 is an explanatory view showing a part of a processing line having an electromagnetic guide device and a spray box in a vertical cross section. FIG. 10, like FIG. 9, is an illustration showing an alternative embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal strip 2 Roller 3 Roller 4 Cross flux heater 5 Magnetic pole 6 Coil 7 Magnetic yoke 8 Magnetic field line 9 End part 10 Position 11 Position 12 Enclosure 13 Detection means 14 Control means 15 Position sensor 16 Proximity sensor 17 Groove 18 Gas injection nozzle

Claims (12)

A device for non-contact guidance of a metal strip (1) over the length of a metal strip freely extending between two mechanical support means (2, 3), which is magnetic or non-magnetic, said metal strip comprising Extending continuously over this length through a passage window between walls or elements to avoid contact, the device being at least perpendicular to the metal strip in a specific zone of said length 2 A set (P1, P2) of magnetic poles is provided, one set being placed on each side of the strip, and the magnetic pole (5) of the strip is a coil (6 ) Is placed such that one set of the poles faces another set of the same polarity poles located on the opposite side of the strip,
The frequency of the magnetic pole (5), the pole spacing, the coil (6) and the alternating current flowing through the coil is divided into the following three zones (A1, B, A2), a device selected to produce
Two zones (A1, A2) in which most of the lines of magnetic force (8) are proximate to each of the magnetic poles (5) and go from one magnetic pole to the opposite pole of the same set,
A central zone (B) in which the relevant magnetic field lines do not pass in part;
The strip (1) is usually in this central zone (B), where it does not receive an easily sensed electromagnetic effect, but the strip deviates from the central zone and is close to the magnetic pole (A1). , A2), when the strip receives an electromagnetic repulsion directed at the central zone (B), the higher this repulsion, the more the strip (1) becomes a wall or the passage For non-contact guidance of the metal strip (1), characterized in that if there is no wall defining the window, it approaches the magnetic pole and does not cause significant parasitic heating, so that the guidance occurs concomitantly apparatus.   The guide device according to claim 1, wherein the width (D) of the passage window is larger than 30 mm.   The guide device according to claim 1 or 2, wherein the width (D) of the passage window is less than 500 mm.   Any of the preceding claims wherein the frequency of the alternating current flowing through the coil (6) is adapted to the desired repulsive force and the material forming the heat shield (Q) between the magnetic pole (5) and the metal strip (1). The guide apparatus as described in any one.   The guide device according to claim 4, wherein the frequency of the alternating current flowing through the coil (6) of the guide device according to claim 4, wherein the induction heating shield is electrically used, is 1 Hz to 30 Hz.   The frequency of the said alternating current which flows through the coil (6) of the guide apparatus of Claim 4 using the heat shield which lets a magnetic flux pass is 30 Hz or more, and it is desirable that it is equal to or more than 1500 Hz. Guidance device.   Guide device according to any one of the preceding claims, characterized in that it comprises a separate enclosure (12) that passes between and surrounds the strip (1) and the magnetic pole (5). .   Any of the preceding claims, wherein the arrangement of the network of magnetic poles (5) allows the distribution of the effect at the end of the metal strip or in the center thereof to optimize the holding of the metal strip in place. The guide apparatus as described in any one.   Any of the preceding claims, wherein the magnetic force of the magnetic pole (5) is applied in the width direction of the metal strip (1) depending on the alignment of the metal strip by the repulsive force caused by the magnetic pole or the effect provided thereby. The guide apparatus as described in any one.   Sensing means (13) sensitive to the magnetic coupling between the metal strip (1) and the electromagnetic set are included, this magnetic coupling being essentially the metal strip (1) to the zones (A1, A2) close to the poles. The sensitive detection means (13), which is activated at the time of entry, is suitable for causing an increase in magnetic repulsion, especially by increasing the magnitude of the alternating current to the coil, when detected by this magnetic coupling. A guide device according to any one of the preceding claims.   Guide device according to any one of the preceding claims, wherein means (17) (18) for blowing gas are inserted in either or both of the magnetic poles (5) or between the magnetic poles.   A method for non-contact guidance of a metal strip over the length of a strip extending freely between two mechanical support means, whether magnetic or non-magnetic, in which at least the length described above A specific frequency alternating magnetic field is created on both sides of the strip (1), and the strength of the magnetic field and its frequency are divided into three zones (A1) in the passage window through which the strip extends. , B, A2), ie, two zones (A1, A2) that are close to the respective magnetic poles (5) and where most of the magnetic field lines (8) are deployed, and a central zone (B) through which the magnetic field lines do not pass The strip (1) is usually in this central zone (B, where it is not subject to easily sensed electromagnetic effects, but the strip (1) deviates from the central zone, Proximity to the magnetic pole When entering into one of the zones (A1, A2) that, strips, a method for contactless guidance of the metal strip, characterized in that for receiving the electromagnetic repulsive force directed to the central zone.

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