DEVICE FOR HEATING A PRODUCT BY CROSS-CURRENT INDUCTION

Description

Designation of the technical field concerned

[0001] The invention relates to devices for heating products by transverse flux induction, in particular flat products such as slabs, thin slabs and strips. Technical problems that the invention addresses

[0002] A product heating device by transverse flux induction mainly comprises a power source, an inductor and electrical linking elements between these pieces of equipment.

[0003] EP 3 471 510 discloses a device for heating a product by transverse flux induction.

[0004] Transverse flux induction heating allows for the efficient heating of products with low magnetic permeability. For example, it allows carbon steel to be heated beyond its Curie point with a high power density, traditionally up to approximately 2500 kW / m².

[0005] This power density may nevertheless be insufficient to achieve the desired temperature increase over a length limited by dimensional or process constraints.

[0006] In steelmaking, continuous casting allows for the production of flat products continuously and directly from molten metal contained in a ladle. The resulting product can be a slab, typically between 35 and 80 mm thick, a thin slab, typically between 5 and 35 mm thick, or a strip, typically 5 mm or less in thickness. After rapid cooling of the metal in an ingot mold to solidify it, induction heating systems bring it to the appropriate rolling conditions, typically between 1100 °C and 1250 °C, in order to obtain the desired product cross-section and metallurgical properties after rolling. Depending on the continuous casting production capacity, the power required to bring the product to the rolling temperature can be several megawatts.Given the rolling temperature and power requirements, it is understood that the heating method is a cross-flow induction system. However, the high-flux cross-flow inductors available allow for power outputs limited to approximately 1.5 MW. To achieve the necessary power output, several inductors are connected in series, one after the other. The resulting total length is significant, for example, 20 m. Steelmakers are demanding that this length be reduced as much as possible. Furthermore, the temperature profile of the product at the end of the heating process is a determining factor for rolling quality. Current cross-flow heating equipment allows for adjustment of this temperature profile, particularly to limit edge overheating, but only within a limited adjustment range that does not fully meet the needs of steelmakers.

[0007] The invention provides a solution to these problems with an inductor and a heating system whose power density injected into the product is very high and offering a greater range of adjustment of the temperature profile of the product allowing to obtain better temperature homogeneity of the product. Summary of the invention

[0008] According to a first aspect of the invention, an inductor is proposed for transverse flux induction heating of a flat product having an upper face and a lower face, said inductor comprising coils having substantially parallel surfaces to each other, and a thickness in a direction perpendicular to these planes, the inductor also comprising a central space between the coils intended to receive the product, in which at least two coils are arranged on a first side of the central space and at least two coils are arranged on a second side of the central space opposite to the first, and on the same side of the central space,The reel closest to the product face is at a distance from it of a certain distance, and the other reels are arranged at a distance from the product face at least equal to the first distance plus the thickness of the reels arranged between them and the product face, and the surfaces of the reels overlap at least partially.

[0009] The presence of at least two coils overlapping at least partially on each side of the product allows the generated magnetic field lines to be varied and thus the temperature rise per unit area of ​​the product to be controlled.

[0010] The invention is of particular interest for inductors equipped with high-flux coils, i.e. made with special conductors, for example comprising a plurality of strands arranged around a tube forming a core through which a cooling fluid flows, as described by FR2989817 of the applicant.

[0011] According to the invention, the coils placed on the same side of the product are as close as possible to each other, in a direction perpendicular to the surfaces on which the coils extend, and preferably in contact with each other, in order to limit parasitic heating and the decrease in efficiency of the inductor which would result from a space between the coils.

[0012] According to one embodiment of the invention, the relative position of the coils, with respect to each other, is adjustable so that the central axes of the coils perpendicular to the surfaces on which the coils extend are all coincident, that these central axes of the coils are all distinct, or that some are coincident and others are distinct along a direction parallel to said surfaces.

[0013] Depending on one possibility, the relative position of the reels with respect to each other is adjustable according to the width of the product and / or according to the length of the product.

[0014] According to the invention, coils located on the same side of the product to be heated can be offset from one another. This offset can be solely along a direction transverse to the product, solely along a direction longitudinal to the product, or both along a longitudinal and a direction transverse to the product.

[0015] Similarly, the coils positioned on either side of the product can be directly opposite each other, or they can be offset only in a direction transverse to the product, only in a direction longitudinal to the product, or both in a longitudinal and transverse direction. The offset may only affect some of the coils. For example, with an inductor according to the invention with two coils on each side of the product, the two coils closest to the product can be directly opposite each other while the two outer coils can be offset, or vice versa. The opposite position of the coils provides the best efficiency. Offsetting the coils can be done, in particular, to influence the temperature profile of the product, but this will reduce the efficiency of the installation.

[0016] According to the invention, the relative position of the coils of an inductor, on either side of the product, is also adjustable so as to modify the distance between the substantially parallel surfaces on which the coils extend, that is to say to modify the air gap.

[0017] Thus, according to the invention, it is possible to modify the distance between the coils and the product, that is, to increase or decrease the air gap. Increasing the air gap is therefore possible if it is desired to lower the power density transmitted to the product, for example, to reduce temperature heterogeneity in the product that would result from an excessively high power density. Advantageously, the coils are moved so that the product is centered between the coils, meaning that the distance between the product and the first coil located on each side of the product is approximately the same.

[0018] On the same face of the product, the second coil from that face is positioned at a distance from the product at least equal to the distance from the first coil plus its thickness. According to the invention, it is possible to modify the distance between the coils located on the same side of the product to be heated. It is thus possible to move the second coil further from the first in order to modify the power density transmitted to the product. In a configuration with more than two coils on one face of the product, the additional coils also have an adjustable position relative to the other coils so as to move them further away from or closer to the product.

[0019] According to a second aspect of the invention, a transverse flux induction heating installation is proposed for a product comprising at least one inductor according to one of the preceding embodiment variants and at least one power source electrically connected to said inductor.

[0020] Depending on the characteristics of the inductor and the power source, the electrical connection between these two pieces of equipment may include a current step-up or step-down transformer and / or capacitors.

[0021] The installation may include a means capable of changing the distance from a coil to the face of the product closest to it.

[0022] According to one possibility, the installation may include a means capable of modifying the relative position of a first reel with respect to a second reel according to the width of the product and / or according to the length of the product.

[0023] According to one embodiment of the invention, the coils of an inductor arranged on one side of the central space of said inductor are supplied by a first power source of at least one power source and the coils arranged on the other side of the central space are supplied by a second power source of at least one power source.

[0024] According to another embodiment of the invention, the two coils closest to the central space are powered by a first power source from at least one power source, and the two coils furthest from the central space are powered by a second power source from at least one power source. If the inductor comprises more than four coils, the coils located between the two coils closest to the central space and the two coils furthest from the central space can be powered by either of the two power sources.

[0025] The power sources can be arranged on one side of the product, in a direction transverse to it, or on each side of the product, in this transverse direction.

[0026] Thus, according to an example of an embodiment of the invention with two coils on each side of the central space, the two coils closest to the central space, constituting a first pair of coils, can be powered by a first power source disposed on one side of the product and the two coils furthest from the central space, constituting a second pair of coils, can be powered by a second power source disposed on the other side of the product.

[0027] According to one embodiment of the invention, the two power sources have different power outputs, the maximum power flow that can be transmitted to the product by the two pairs of coils being different.

[0028] According to one embodiment of the invention, the transverse flux induction heating system comprises at least two successive inductors along the longitudinal direction of the product. Thus, the first inductor is, for example, intended to provide an initial temperature rise in the product, and the second inductor is intended to provide a further temperature rise. The two inductors may have the same effect on the temperature profile of the product exiting the inductor, or they may have different, for example, opposing effects, depending on the relative position of the inductor coils. For example, the first inductor may have a coil working position that leads to a significant temperature rise on one of the two edges of the product, in a direction transverse to it, while the second inductor may have a coil working position opposite to the first, leading to a significant temperature rise on the other edge of the product.It is therefore possible to adjust the product's temperature profile after each inductor to obtain the desired temperature profile at the outlet of the last inductor. For example, with a solution comprising two successive inductors and a product entering the first inductor with edges cooler than its center, the first inductor can raise the temperature level of one edge of the product, and the second inductor can raise the temperature of the other edge of the product, so that at the outlet of the second inductor, the product has reached the desired temperature rise while maintaining a homogeneous temperature, or the desired temperature profile.

[0029] According to a third aspect of the invention, a method of transverse flux induction heating of a product is proposed using an installation according to one of the embodiments described above, characterized in that the relative position of the coils of an inductor, with respect to each other and with respect to the product, is adjusted according to the temperature profile of the product targeted at the outlet of the inductor.

[0030] The position of the reels can be adjusted manually by an operator, who positions the reels and then clamps them in the working position. Adjustment can also be achieved mechanically, using rack and pinion or sliding motion systems. Alternatively, adjustment can be performed electrically, pneumatically, or hydraulically, for example, using cylinders. Finally, adjustment can be automated by motorizing the movements.

[0031] The adjustment of the position of the coils can be carried out by an action of an operator or automatically according to the characteristics of the product, in particular its width, and / or the desired temperature profile of the product at the outlet of the inductor. Brief description of the figures

[0032] Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for which reference should be made to the accompanying drawings in which: [ Fig. 1 [ ] is a schematic longitudinal cross-sectional view of an inductor, according to an exemplary embodiment of the invention, in a first working position. Fig. 2 ] is a schematic cross-sectional view of the inductor shown in figure 1 , in the same working position as in figure 1 . [ Fig. 3] is a schematic top view of the inductor shown in the previous figures, in the same working position as in figures 1 and 2 . [ Fig. 4 ] is a schematic top view of the inductor shown in the preceding figures, in a second working position. Fig. 5 ] is a schematic cross-sectional view of the inductor shown in the previous figures, in the same working position as in figure 4 . [ Fig. 6 ] is a schematic top view of the inductor shown in the preceding figures, in a third working position. Fig. 7 ] is a schematic longitudinal cross-sectional view of the inductor shown in the previous figures, in the same working position as in figure 6 . [ Fig. 8 ] is a schematic longitudinal cross-sectional view of the inductor shown in the preceding figures, in a fourth working position. Fig. 9[ ] is a schematic longitudinal cross-sectional view of an inductor according to the invention, with two examples of a cylinder head embodiment, the upper part of the figure illustrating a first example and the lower part of the figure a second example. Fig. 10 [ ] is a typical electrical assembly diagram illustrating a first example of connecting the coils of an inductor according to the invention. Fig. 11 [ ] is a typical electrical assembly diagram illustrating a second example of connecting the coils of an inductor according to the invention. Fig. 12 [ ] is a typical electrical assembly diagram illustrating a third example of connecting the coils of an inductor according to the invention. Fig. 13 [ ] is a typical electrical assembly diagram illustrating a fourth example of connecting the coils of an inductor according to the invention. Fig. 14] is a diagram illustrating an example of implementation of the process according to the invention with the evolution of the transverse temperature profile of a product at the outlet of four successive inductors according to the invention.

[0033] The embodiments described below are not exhaustive; variants of the invention may include only a selection of the described features, hereinafter isolated from the other described features, if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the prior art. This selection includes at least one feature, preferably functional, without structural details, or with only a portion of the structural details if this portion alone is sufficient to confer a technical advantage or to differentiate the invention from the prior art.

[0034] In the following description, elements with an identical structure or analogous functions will be designated by the same references. Detailed description of the invention

[0035] THE figures 1 to 8 These diagrams schematically illustrate the same embodiment of an inductor 20 according to the invention in potentially different working positions. The inductor allows the heating of a flat product 1. This product defines a longitudinal direction along its length and a transverse direction across its width.

[0036] A transverse flux inductor typically comprises coils that generate an electromagnetic field which heats the product, and yokes designed to channel this magnetic field to improve the inductor's efficiency. On each side of the product to be heated, the coil and yokes are mounted on a plate. The inductor typically includes thermal protection that acts as a barrier to radiation from the product. This thermal protection can also be gas-tight when it is necessary to place the product in an atmosphere other than air, for example, in an atmosphere that is non-oxidizing for the product. Alternatively, the gas-tightness can be achieved separately from the thermal protection. For simplicity in illustrating the invention, only the coils are shown in the figures.

[0037] THE figures 1 to 3schematically illustrate inductor 20 in a first example of a working position. figure 1 is a longitudinal cross-sectional view of the inductor, the figure 2 is a cross-sectional view of the inductor and the figure 3 is a top view of the inductor.

[0038] The inductor 20 comprises two pairs of coils 2as, 2ai, 2bs, 2bi arranged on either side of a central space 3 in which the product 1 to be heated is located. It can be seen on these figures 1 to 3 In this example of a working position, the four coils are perfectly superimposed, their central axes 4as, 4ai, 4bs, 4bi coinciding in the longitudinal and transverse directions. This configuration is suitable, for example, when the dimensions of the coils allow them to cover the width of the product to be heated when they are stacked.

[0039] From the upper face 1fs of the product 1 to be heated, the first coil 2ai is located at a distance Dai, meaning that the plane P2ai on which the surface S2ai of coil 2ai lies is a distance Dai from the upper face 1fs of the product. This distance Dai strongly influences the power density transmitted to the product by the coil. To adjust the power transmitted to the strip, this distance is adjustable by means 21 shown in figure 2 .

[0040] This means 21 includes, for example, a worm screw whose longitudinal axis is perpendicular to the face 1fs of the product and a nut fixed to the spool with which the worm screw cooperates. Thus, the position of the spool is adjusted by rotating the worm screw. The means 21 can also be a rack, a linear motor, a cylinder, or any other known means.

[0041] The second reel 2as is placed at a distance Das from the upper face 1fs of the product; that is, the plane P2as on which the surface S2as of reel 2as lies is a distance Das from the upper face 1fs of the product. This distance Das is at least equal to the distance Dai at which the first reel is positioned, plus its thickness. This distance Das also strongly influences the power density transmitted to the product by the reel. To adjust the power transmitted to the tape, the distance Das is also adjustable by a second means 21 shown in figure 2 .

[0042] Starting from face 1fi of the product 1 to be heated, the first coil 2bi is located at a distance Dbi, meaning that the plane P2bi on which the surface S2bi of coil 2bi lies is a distance Dbi from the lower face 1fi of the product. This distance Dbi strongly influences the power density transmitted to the product by the coil. To adjust the power transmitted to the strip, this distance is adjustable by a means 21 shown in figure 2 .

[0043] The second reel 2bs is placed at a distance Dbs from the lower face 1fi of the product; that is, the plane P2bs on which the surface S2bs of reel 2bs lies is a distance Dbs from the lower face 1fi of the product. This distance Dbs is at least equal to the distance Dbi at which the first reel is positioned, plus its thickness. This distance Dbs also strongly influences the power density transmitted to the product by the reel. To adjust the power transmitted to the tape, the distance Dbs is also adjustable by a second means 21 shown in figure 2 .

[0044] THE figures 4 And 5 illustrate the inductor 20 in a second working position adapted to a wider product than in the first working position example. figure 4 is a top view of the inductor and the figure 5is a cross-sectional view of the inductor. The longitudinal cross-sectional view of the inductor would be identical to the figure 1 The position of the reels in the longitudinal direction is the same for both examples of working position. In this second working position, the reels are offset transversely to cover the entire width of the product.

[0045] The transverse position of a coil is adjustable by means 22 shown in figure 4 This means 22 includes, for example, a worm screw whose longitudinal axis is parallel to the face 1fs of the product and a nut fixed to the spool with which the worm screw cooperates. Thus, the position of the spool is adjusted by rotating the worm screw. The means 22 can also be a rack, a linear motor, a cylinder, or any other known means. In the example embodiment of the figure 4The two coils arranged on the same face of the product are equipped with a means 22 for adjusting their transverse position. According to another embodiment of the invention, only one coil is equipped with a means 22 for adjusting its transverse position.

[0046] THE figures 6 And 7 illustrate inductor 20 in a third working position. The figure 6 is a top view of the inductor and the figure 7 is a longitudinal cross-sectional view of the inductor. The cross-sectional view of the inductor would be identical to the figure 5 , the position of the coils in the transverse direction being the same for the second and third example of working position.

[0047] The longitudinal position of a coil is adjustable by means 23 shown in figure 6This means 23 may be similar to that used to adjust the transverse position of a coil, or it may be different. In the example of the implementation of the figure 6 The two reels arranged on the same face of the product are equipped with a means 23 for adjusting their longitudinal position. According to another embodiment of the invention, only one reel is equipped with a means 23 for adjusting its longitudinal position.

[0048] There figure 8 Figure 20 represents the inductor, in longitudinal sectional view, in a fourth working position. This example illustrates a working position in which there is an asymmetry between the coils with respect to the product to be heated. Thus, coil 2as is not opposite coil 2bs. Any other variant of asymmetry is possible according to the invention.

[0049] A coil is advantageously made from an assembly of conductors. Each conductor comprises a plurality of strands of electrically conductive material, for example, copper, arranged around a tube of electrically insulating material forming a core through which a cooling fluid flows. The strands are impregnated with an electrically insulating paste having a good coefficient of thermal conductivity to ensure efficient heat transfer between the strands and the tube. A coil is, for example, made from an assembly of conductors placed side by side on the same plane of the coil. At each end, the conductors are electrically connected to each other in a connection element to the power source. Similarly, at each end, the tubes of insulating material open into a cavity forming a manifold for supplying or draining the cooling fluid, depending on the end.

[0050] Advantageously, a coil comprises two superimposed and juxtaposed assemblies as described previously, that is, two layers of conductors on two parallel planes. In an alternative embodiment, the connection elements to the power source and / or the connection points to the cooling fluid are common to both layers of conductors.

[0051] To simplify the figures illustrating the coils, their electrical and hydraulic connections have not been shown.

[0052] According to one embodiment of the invention, the inductor comprises at least one yoke on each side of the product. A yoke is formed by stacking silicon steel sheets separated by electrical insulation. This stacking allows the yoke to channel the electromagnetic field generated by the coils while preventing the flow of electric current within the yoke. figure 9This illustrates two examples of a yoke 5 in a longitudinal cross-sectional view at mid-width of a product 1, noting that on a real inductor, the yokes are identical on both sides of the inductor. In the upper part of the figure, the yoke has a central extension that fits inside the coils. This extension is absent in the embodiment shown in the lower part of the figure. The efficiency of the yoke is better if it includes a central extension, but this limits the possible transverse movement of the coils. Conversely, an inductor with yokes without a central extension will have lower efficiency, but it will offer a greater range of adjustment for the relative position of the coils.

[0053] THE figures 10 to 13are simplified electrical diagrams that illustrate different ways of connecting an inductor to two pairs of coils according to the invention, by way of example, without these being limiting.

[0054] There Figure 10 This illustrates a series / parallel circuit in which a power source 6 supplies the four inductor coils. Two coils located on one side of the product, 2as and 2ai, are connected in parallel, while the other two coils, 2bs and 2bi, located on the opposite side of the product, are also connected in parallel. The two pairs of coils are connected in series. The circuit includes a capacitor 7 arranged in series.

[0055] There figure 11This illustrates a series circuit in which the inductor is powered by two power sources 6. One power source 6 supplies the pair of coils 2as, 2bs furthest from the product, these being connected in series. The second power source 6 supplies the pair of coils 2ai, 2bi closest to the product, these also being connected in series. Each circuit includes a capacitor 7 arranged in series.

[0056] There figure 12 This also illustrates a configuration with two power sources 6, but whose coils are connected in parallel. Thus, one power source 6 supplies the pair of coils 2as, 2bs furthest from the product, these being connected in parallel, and the second power source 6 supplies the pair of coils 2ai, 2bi closest to the product, these also being connected in parallel. Again, each circuit includes a capacitor 7 arranged in series.

[0057] In the variants represented in Figures 11 and 12 The two power sources 6 can be arranged on the same side of the product, or one source can be placed on each side of the product.

[0058] There figure 13 illustrates a setup similar to the one shown in figure 12 in which the inductor is powered by a dual-output power source 6. One output of the power source 6 supplies the pair of coils 2as, 2bs furthest from the product, these being connected in series. The second output of the power source 6 supplies the pair of coils 2ai, 2bi closest to the product, these also being connected in series. Each circuit includes a capacitor 7 arranged in series.

[0059] According to an example of the application of the invention to the case of the production of thin steel slabs by continuous casting, four successive installations make it possible to raise the temperature of the product from 900 °C to 1000 °C. Each installation comprises a power source connected to an inductor having two coils arranged on either side of the product. The coils are electrically connected according to the principle diagram of the Figure 10 They are powered by a current of up to 4000 A at a voltage of 2500 V and a frequency of 1000 Hz. The relative position of the coils of the four installations is adjusted so as to obtain at the output, a product at 1000 °C with the desired transverse temperature profile.

[0060] There figure 14This diagram represents a transverse temperature evolution diagram of a product, illustrating an example of implementing the process according to the invention for this application of heating a thin slab. The vertical axis of this diagram represents the product temperature, and the horizontal axis represents the product width. Curve A represents the transverse temperature profile of the product at the inlet of the first inductor, with the product edges being significantly cooler than the center. Curve B represents the temperature profile of the product at the outlet of the first inductor. The relative position of the coils of the first inductor is such that it promotes strong heating of the product edge located to the left of the diagram. Curve C represents the temperature profile of the product at the outlet of the second inductor.The relative position of the coils in the second inductor is such that it promotes greater heating of the product's right-hand edge on the diagram. Curve D represents the product's temperature profile at the outlet of the third inductor. The relative position of the coils in the third inductor is such that it promotes slightly greater heating of the left-hand edge on the diagram. Curve E represents the product's temperature profile at the outlet of the fourth and final inductor. The relative position of the coils in the last inductor is such that it promotes slightly greater heating of the right-hand edge on the diagram, thus obtaining a homogeneous product temperature profile.

Claims

1. Inductor (20) intended for heating a flat product (1) by transverse flux induction, the flat product having an upper face (1fs) and a lower face (1fi), said inductor comprising coils (2as, 2ai, 2bs, 2bi) that have surfaces (S2as, S2ai, S2bs, S2bi) extending over planes (P2as, P2ai, P2bs, P2bi) substantially parallel to one another, and a thickness (Eas, Eai, Ebs, Ebi) in a direction perpendicular to these planes, the inductor also comprising a central space (3) between the coils that is intended to receive the product (1), wherein at least two coils (2as, 2ai) are arranged on a first side of the central space (3) and at least two coils (2bs, 2bi) are arranged on a second side of the central space (3) opposite the first side, wherein on the same side of the central space (3), the coil (2ai, 2bi) closest to the face (1fs, 1fi) of the product is spaced therefrom by a first distance (Dai, Dbi) and the other coils are arranged at a distance from the face of the product that is at least equal to the first distance (Dai, Dbi) plus the thickness (Eai, Ebi) of the coils arranged between them and the face of the product, and the surfaces (P2as, P2ai, P2bs, P2bi) of the coils at least partially overlap, characterized in that the relative position of the coils is adjustable so as to modify the distance of the coils from the face of the product that is closest to them.

2. Inductor according to claim 1, the coils (2as, 2ai, 2bs, 2bi) having a central axis (4as, 4ai, 4bs, 4bi) perpendicular to the surfaces (P2as, P2ai, P2bs, P2bi), characterized in that the relative position of the coils with respect to one another is adjustable such that the central axes (4as, 4ai, 4bs, 4bi) of the coils are all coincident, the central axes of the coils are all separate or some are coincident and others are separate in a direction parallel to said surfaces (P2as, P2ai, P2bs, P2bi).

3. Inductor according to claim 2, characterized in that the relative position of the coils with respect to one another is adjustable according to the width of the product and / or according to the length of the product.

4. Inductor according to claims 1 or 2, wherein the relative position of the coils with respect to one another is adjustable so as to modify the distance between two substantially parallel surfaces (P2as, P2ai, P2bs, P2bi) over which the coils extend.

5. Installation for heating a product (1) by transverse flux induction, comprising at least one inductor (20) according to one of the preceding claims and at least one power source (10) electrically connected to said inductor.

6. Installation for heating a product (1) by transverse flux induction according to the preceding claim, comprising a means (21) able to modify the distance of a coil from the face of the product that is closest to it.

7. Installation for heating a product (1) by transverse flux induction according to claim 5, comprising a means (22, 23) able to modify the relative position of a first coil with respect to a second coil according to the width of the product and / or according to the length of the product.

8. Installation for heating a product (1) by transverse flux induction according to claim 5, wherein the coils (2as, 2ai, 2bs, 2bi) of an inductor (20) that are arranged on one side of the central space (3) of said inductor are supplied by a first power source (10) of the at least one power source (10) and the coils arranged on the other side of the central space (3) are supplied by a second power source (10) of the at least one power source.

9. Installation for heating a product (1) by transverse flux induction according to claim 5, the coils (2ai, 2bi) closest to the central space being supplied by a first power source (10) of the at least one power source (10) and the coils (2as, 2bs) furthest from the product being supplied by a second power source (10) of the at least one power source (10).

10. Installation for heating a product (1) by transverse flux induction according to one of claims 5 to 9, comprising at least two consecutive inductors (20) in the longitudinal direction of the product.

11. Method for heating a product (1) by transverse flux induction by means of an installation according to one of claims 5 to 10, characterized in that the relative position of the coils (2as, 2ai, 2bs, 2bi) of an inductor (20) with respect to one another and with respect to the product is adjusted according to the temperature profile of the product desired at the inductor outlet.