An inductive heating device

Abstract

The present application belongs to the technical field of electromagnetic induction heating, and relates to an induction heating device, which comprises an induction heating unit for heating metal plates, the induction heating unit comprising an induction heating coil, an edge magnetic field shield and a magnetic conductor, the induction heating coil being arranged on a plane parallel to the metal plate, the edge magnetic field shield being arranged between the corresponding induction heating coil and the metal plate and located on one side in the width direction of the metal plate, and the magnetic conductor being arranged on the middle part of the main body in the width direction of the metal plate; the induction heating units are arranged in sequence along the running direction of the metal plate and at least in n groups, two adjacent induction heating units being arranged symmetrically and staggeredly on both sides of the center line of the metal plate, and n being an even number greater than or equal to 2. The present application effectively solves the problem of edge overheating in the field of transverse flux induction heating and improves the temperature uniformity in the width direction of the material.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electromagnetic induction heating and relates to an induction heating device. BACKGROUND

[0002] Electromagnetic induction is divided into longitudinal magnetic flux induction heating and transverse magnetic flux induction heating, both of which have the advantages of large output power density, fast heating speed and zero carbon emission. The magnetic force lines of longitudinal magnetic flux induction heating are parallel to the surface of the material, and its heating capacity depends on the skin effect related to the frequency. The thinner the metal plate is, the higher the power frequency requirement is, and the higher the magnetic loss is, and the lower the power efficiency is. The magnetic force lines of transverse magnetic flux induction heating are perpendicular to the surface of the material, and can generate induced current within the thickness range of the metal plate. The heating capacity has no high requirement for the power frequency, can effectively heat non-magnetic conductive materials, and has no defects such as magnetic loss, and has higher energy efficiency advantage and smaller power design difficulty in the field of heating of relatively thin materials such as continuous annealing of strip steel or intermediate heating of non-magnetic materials in ESP thin plate continuous casting and rolling.

[0003] However, in the actual application of transverse magnetic flux induction heating, the projection of the edge coil on the surface of the metal plate has a relatively large proportion, which causes the magnetic force lines to concentrate in the edge area (the edge area in the width direction of the material), and causes the edge of the steel plate to overheat. Especially when the width of the metal plate becomes narrower, the magnetic force line density is more concentrated in the edge of the metal plate, the local eddy current is stronger, and the edge overheating is more serious. SUMMARY

[0004] Therefore, the purpose of the application is to provide a transverse magnetic flux induction heating device to effectively solve the problem of edge overheating in the field of transverse magnetic flux induction heating and improve the temperature uniformity in the width direction of the material.

[0005] To achieve the above purpose, the application provides the following technical scheme:

[0006] An induction heating device includes an induction heating unit for heating a metal plate, the induction heating unit includes an induction heating coil, an edge magnetic field shield and a magnetic conductor, the induction heating coil is arranged on a plane parallel to the metal plate, the edge magnetic field shield is arranged between the corresponding induction heating coil and the metal plate and is located on one side in the width direction of the metal plate, and the magnetic conductor is arranged on the central body in the width direction of the metal plate.

[0007] The induction heating units are arranged in the running direction of the metal plate in sequence and at least in n groups, two adjacent induction heating units are arranged symmetrically on both sides of the center line of the metal plate in staggered mode, and n is an even number greater than or equal to 2.

[0008] Further, the magnetic conductor is open wrapped on the induction heating coil, and the wrapping open surface of the magnetic conductor is coplanar with the opposite surface of the induction heating coil and the metal plate.

[0009] Further, the induction heating coil is an inner-outer nested multi-layer rectangular coil, and the number of nested layers of the inner-outer nested multi-layer rectangular coil is not less than 2, and the adjacent nested layers are obliquely pulled in series or wound from inside to outside in the form of involute.

[0010] Further, the induction heating coil is a plurality of inner-outer nested multi-layer rectangular coils arranged side by side in series, and the number of nested layers of a single inner-outer nested multi-layer rectangular coil is not less than 2, and the adjacent nested layers are obliquely pulled in series.

[0011] Further, on the side of the induction heating unit where no edge magnetic field shield is arranged, the edge of the magnetic conductor in the width direction of the metal plate is projected on the surface of the metal plate within the metal plate, and the distance between the edge and the edge of the metal plate corresponding to the edge is L1, and on the side where the edge magnetic field shield is arranged, the edge magnetic field shield is projected on the surface of the metal plate to cover the width of the metal plate, and the distance is L2.

[0012] The distance between the metal plate and the induction heating coil is H1, the thickness of the metal plate is H2, and L1=a*H1, L2=L1+b*H1, 0.2

[0013] Further, the a and b are pre-configured according to the thickness H2 of the metal plate and the edge overheating amplitude, the greater the thickness H2 or the smaller the edge overheating amplitude, the greater the set value of a and b.

[0014] Further, the induction heating unit is mirror arranged on the upper and lower surfaces of the metal plate.

[0015] The beneficial effects of the present application are:

[0016] The present application cancels the magnetic conductor at the edge of the induction heating coil, only uses open wrapping to arrange the magnetic conductor on the middle main body of the induction heating coil in the width direction of the metal plate, slows down the enrichment effect of the magnetic force line at the edge of the material, controls the relative position relationship between the magnetic conductor and the edge magnetic field shield and the metal plate according to the thickness of the metal plate and the edge overheating amplitude to dilute the enrichment density of the magnetic force line at the edge of the material, reduces the edge overheating amplitude, and simultaneously realizes the active and accurate control of the edge overheating amplitude through the staggered arrangement and combined application of the two groups of induction heating units, controls the edge overheating amplitude according to the production needs, so as to offset the influence of the edge overheating on the temperature uniformity in the width direction of the material.

[0017] Additional advantages, objects, and features of the application will be apparent to those skilled in the art upon examination of the following specification. It is intended that the application not be limited by any of the details of the specification. Accordingly, the BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the objects, technical solutions and advantages of the present application clearer, the preferred embodiments of the present application will be described in detail below with reference to the drawings, in which:

[0019] Figure 1 Structure diagram of a transverse flux induction heating device (for heating a wider metal plate) in an embodiment;

[0020] Figure 2 Structure diagram of a transverse flux induction heating device (for heating a narrower metal plate) in an embodiment;

[0021] Figure 3 Structure diagram of a transverse flux induction heating device in an embodiment;

[0022] Figure 4 Structure diagram of a single induction heating coil in an embodiment;

[0023] Figure 5 Structure diagram of a plurality of induction heating coils connected in series in an embodiment;

[0024] Figure 6 Structure diagram of a transverse flux induction heating device (four groups of induction heating units) in an embodiment;

[0025] Figure 7 Heating curve of a metal plate in an embodiment.

[0026] Reference signs: induction heating unit 1, metal plate 2, induction heating coil 1-1, edge magnetic field shield 1-2, magnetic conductor 1-3. DETAILED DESCRIPTION

[0027] The present application is described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0028] The drawings are only used for exemplary illustration, and the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation on the present application; in order to better illustrate the embodiments of the present application, some components of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it should be understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, and for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0030] Please refer to Figures 1-5 The present application is an induction heating device, which comprises an induction heating unit 1 for heating a metal plate 2, the induction heating unit 1 comprises an induction heating coil 1-1, an edge magnetic field shield 1-2 and a magnetic conductor 1-3, the induction heating coil 1-1 is arranged in parallel to the plane of the metal plate 2, the edge magnetic field shield 1-2 is arranged between the corresponding induction heating coil 1-1 and the metal plate 2, and is located on one side of the metal plate 2 in the width direction, and the magnetic conductor 1-3 is arranged on the central main body of the induction heating coil 1-1 in the width direction of the metal plate 2; the induction heating unit 1 is arranged in the running direction of the metal plate 2, and at least two groups of induction heating units 1 are arranged in the running direction of the metal plate 2, the number of groups is even, and two adjacent induction heating units 1 are arranged symmetrically on both sides of the center line of the metal plate 2.

[0031] Specifically, in the present embodiment, the induction heating coil 1-1 is two side-by-side series of inner and outer nested multi-layer rectangular coils to achieve the maximum coil expansion length, under the same heating power condition, to reduce the coil input current, and the number of nested layers of a single inner and outer nested multi-layer rectangular coil is not less than 2, and the adjacent nested layers are obliquely tensioned in series or wound from inside to outside in the form of an involute; and a magnetic conductor 1-3 is arranged on the induction heating coil 1-1 to constrain the distribution of the induction magnetic force line, improve the induction heating efficiency, and the magnetic conductor 1-3 does not cover both ends of the induction heating coil 1-1 (both ends in the width direction of the metal plate 2) to reduce the enrichment degree of the induction magnetic flux at the edge of the metal plate 2, and control or eliminate the edge overheating effect.

[0032] In the side of the induction heating unit 1 where no side magnetic field shield 1-2 is arranged, the edge of the magnetic conductor 1-3 in the width direction of the metal plate 2 is projected on the surface of the metal plate 2 within the metal plate 2, and the distance between the edge and the edge of the metal plate 2 corresponding to the edge is L1, and in the side where the side magnetic field shield 1-2 is arranged, the side magnetic field shield 1-2 is projected on the surface of the metal plate 2 to cover the width of the metal plate 2, which is L2; the distance between the metal plate 2 and the induction heating coil 1-1 is H1, the thickness of the metal plate 2 is H2, and L1=a×H1, L2=L1+b×H1, 0.2

[0033] The metal plate 2 with a certain width and thickness is heated: in the side of the induction heating unit 1 where no side magnetic field shield 1-2 is arranged, the distance between the edge of the magnetic conductor 1-3 and the edge of the metal plate 2 is L1, and the edge of the steel plate is heated by using the enrichment effect of the side magnetic field, so that the heating capacity of the area without the projection of the magnetic conductor 1-3 and the heating capacity of the middle area (with the projection of the magnetic conductor 1-3) are in a preset balanced relationship; in the side where the side magnetic field shield 1-2 is arranged, the side magnetic field shield 1-2 is arranged between the induction heating coil 1-1 and the metal plate 2 to control the edge heating amplitude on the side where the side magnetic field shield 1-2 is arranged, according to the change of the width of the metal plate 2, the position of the side magnetic field shield 1-2 is adjusted, so that the projection of the magnetic field shield on the surface of the metal plate 2 satisfies that the width of the projection of the side magnetic field shield 1-2 covering the edge of the metal plate 2 is L2; the heating capacity of the area covered by the side magnetic field shield 1-2 and the heating capacity of the middle area are also in a preset balanced relationship.

[0034] The specific heating process of the metal plate 2 with specific width and thickness is as follows: the center line position of the metal plate 2 is fixed, each component of the induction heating unit 1 is moved to both sides (in the width direction of the metal plate 2), and the projection of each component of the offset induction heating unit 1 on the surface of the metal plate 2 meets the requirements of L1 and L2, and the induction heating unit 1 is arranged in pairs along the running direction of the metal plate 2 and is arranged symmetrically on both sides of the center line of the metal plate 2; when the metal plate 2 passes through the previous induction heating unit 1, the middle part is normally heated, the edge part of the material on the side of the magnetic field shielding device 1-2 is less or almost not heated, and the edge part of the metal plate 2 on the side of the magnetic field shielding device 1-2 is excessively heated under the action of the magnetic flux enrichment of the edge part of the induction heating coil 1-1; the metal plate 2 continues to pass through the next induction heating unit 1, and the positions of the side of the magnetic field shielding device 1-2 and the side without the magnetic field shielding device 1-2 are exchanged, the previously excessively heated edge part of the metal plate 2 is not heated or less heated, and the previously not heated or less heated edge part of the metal plate 2 is excessively heated due to the shielding of the magnetic flux by the magnetic field shielding device 1-2; after passing through the two induction heating units 1, the heating amplitudes of the two edge parts of the metal plate 2 tend to be consistent, and the edge heating amplitude is controlled by L1 and L2 to achieve the preset balance relationship between the edge heating amplitude and the middle heating amplitude.

[0035] By adjusting the sizes of L1 and L2, the difference between the edge temperature and the middle position of the metal plate 2 can be controlled; when the width specification of the metal plate 2 changes, the positions of each component in the induction heating unit 1 are adjusted according to the change of the width of the metal plate 2, so that the projection of each component on the surface of the metal plate 2 meets the requirements of L1 and L2. Moreover, for thinner materials, the heat dissipation of the edge part is larger, and the temperature of the edge part is lower when entering the induction heating device, so that the edge part can be heated by adjusting L1 and L2.

[0036] Please refer to Figure 6 and Figure 7 , which are induction heating devices composed of four groups of induction heating units 1, the four groups of induction heating units 1 are arranged in sequence along the running direction of the metal plate 2, and two adjacent induction heating units 1 are arranged symmetrically on both sides of the center line of the metal plate 2, the temperature curve of the metal plate 2 before entering the induction heating device and during the heating process is shown in Figure 7 , through the staggered arrangement and combined application of the induction heating units 1, the active and accurate control of the edge overheating amplitude is realized, the influence of the edge overheating on the temperature uniformity in the width direction of the metal plate 2 is offset, and the temperature uniformity in the width direction of the metal plate 2 is realized.

[0037] Finally, it is to be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not to limit the present application. Although the present application is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions, and all should be covered in the scope of the claims of the present application.

Claims

1. An induction heating device comprising an induction heating unit (1) for heating a metal sheet (2), characterized in that: The induction heating unit (1) comprises an induction heating coil (1-1), an edge magnetic field shield (1-2) and a magnetic conductor (1-3), the induction heating coil (1-1) is arranged on a plane parallel to the metal plate (2), the edge magnetic field shield (1-2) is arranged between the corresponding induction heating coil (1-1) and the metal plate (2) and is located on one side of the metal plate (2) in the width direction, and the magnetic conductor (1-3) is arranged on the central main body of the induction heating coil (1-1) in the width direction of the metal plate (2). The induction heating units (1) are arranged in the running direction of the metal plate (2) in turn and at least in n groups, two adjacent induction heating units (1) are arranged symmetrically on both sides of the center line of the metal plate (2) in a staggered manner, and n is an even number greater than or equal to 2. On the side of the induction heating unit (1) without the edge magnetic field shield (1-2), the edge of the magnetic conductor (1-3) in the width direction of the metal plate (2) is projected on the surface of the metal plate (2) and located in the metal plate (2), and the distance between the edge and the edge of the metal plate (2) corresponding to the edge is L1, and on the side with the edge magnetic field shield (1-2), the edge magnetic field shield (1-2) is projected on the surface of the metal plate (2) and covers the width of the metal plate (2) with a width of L2. The distance between the metal plate (2) and the induction heating coil (1-1) is H1, the thickness of the metal plate (2) is H2, L1=a*H1, L2=L1+b*H1, 0.2 The a and b are set according to the thickness H2 of the metal plate (2) and the edge overheating amplitude, the greater the thickness H2 or the smaller the edge overheating amplitude, the greater the set value of a and b; The induction heating unit (1) is arranged in a mirror image on the upper and lower surfaces of the metal plate (2).

2. The inductive heating device of claim 1, wherein: The magnetic conductor (1-3) is open-coated on the induction heating coil (1-1), and the open-coated surface of the magnetic conductor (1-3) is coplanar with the opposite surface of the induction heating coil (1-1) and the metal plate (2).

3. The inductive heating device of any one of claims 1-2, wherein: The induction heating coil (1-1) is an inner-outer nested multi-layer rectangular coil, and the number of nested layers of the inner-outer nested multi-layer rectangular coil is not less than 2, and the adjacent nested layers are in a diagonal pull series or are wound from inside to outside in a involute form.

4. The inductive heating device of claim 3, wherein: The induction heating coil (1-1) is a plurality of inner-outer nested multi-layer rectangular coils arranged side by side in series, and the number of nested layers of a single inner-outer nested multi-layer rectangular coil is not less than 2, and the adjacent nested layers are in a diagonal pull series.

Images