WO2008054070A1

WO2008054070A1 - A heating apparatus and luminous apparatus using induction heating

Info

Publication number: WO2008054070A1
Application number: PCT/KR2007/004916
Authority: WO
Inventors: Sung Il Kim
Original assignee: Sung Il Kim
Priority date: 2006-11-03
Filing date: 2007-10-09
Publication date: 2008-05-08
Also published as: KR100818944B1

Abstract

There is provided to a heating apparatus using an induction heating, including: a power supply unit for supplying an alternating current; an induction coil for generating an alternating magnetic flux by the alternating current; and a heating body having a plate shape or a tube shape including a ferromagnetic body or a ferromagnetic alloy having a high heating efficiency for being heated by the alternating magnetic flux, wherein the heating body includes a material having a higher curie temperature than a maximum operation.

Description

A HEATING APPARATUS AND LUMINOUS APPARATUS USING INDUCTION HEATING

Technical Field

[1] The present invention relates to a heating apparatus and a luminous apparatus using induction heating; and, more particularly, to a heating apparatus and a luminous apparatus using induction heating including a heating plate which is heated, or a luminous plate which is emitted by an alternative magnetic flux generated in an induction coil. Background Art

[2] In general, a heat for life is acquired by burning coal, oil and gas, or supplying an electric current to an electric resistance. However, as an income level increases, the use of heating apparatuses using electricity increase due to convenience of the use and a characteristic which maintains comfortable and fresh indoors without consuming an oxygen.

[3] The heating apparatuses using electricity use a joule's heat generated by an electric flowing on a resistor, and use a nicrome wire heating body, a ceramic heating body, a Positive Temperature Coefficient (PTC) heating body and a carbon heating body as a heating body.

[4] The heating apparatuses using induction heating reduces an electricity fare by having a higher heating efficiency than other heating apparatuses using other electricity. However, a conventional heating apparatus using the induction heating is used for an industrial utility, and recently, an electric rice cooker using the induction heating is popularized in a domestic market.

[5] However, the conventional induction heating apparatuses used in industry or home uses a method for generating a squirrel current of a conductor in a conductive plate material or a conductive cooker for cooking a food. In this case, the conventional induction heating apparatuses has demerits that a heating body to be heated is a conductor and a heating power is changed in a case that a material characteristic of the heating body to be heated is changed in the cooker.

[6] Fig. 1 shows a simple configuration of a conventional induction heating cooker 90 to describe the demerits of the conventional induction heating apparatuses. As shown in Fig. 1, the conventional induction heating cooker 90 includes a power supply unit 10 which supplies an Alternating Current(AC) power, an induction coil 20 which generates an AC flux by the AC power, and a conductive cooker(30) which is heated by a squirrel current 1 generated by the AC flux 2, and stores a food. [7] As described above, the conventional induction heating apparatuses uses a method for heating a bottom plane of the cooker by generating the squirrel current on the bottom plane of the cooker from the AC flux 2 generated by the induction coil 20.

[8] Since an amplitude of the squirrel current is changed in case that a permeability of the cooker 30 used in the conventional heating apparatuses used at home is changed, to compensate the amplitude of the squirrel current, a conventional high frequency power supply unit has a complicated configuration and a high cost by further including a detection circuit for detecting a permeability change of the cooker, and a frequency change circuit for changing a frequency of a current which is provided to the induction coil.

[9] Further, in case that a cooker having a low permeability such as a copper or aluminum is used in the conventional induction heating apparatuses 90, a heating efficiency is lowered and a using power is increased.

[10] As shown in Fig. 1, the conventional induction heating apparatuses used in the industry 90 use a method for directly heating the object by a squirrel current.

[11] On the other hand, an incandescent lamp and a fluorescent lamp are used as a luminous apparatus at home. The incandescent lamp and fluorescent lamp use a filament made of a tungsten wire. Since the tungsten wire is getting evaporated at higher than 2000⁰C and the filament is off, the incandescent lamp is used for about 1000 hours and the fluorescent lamp is used for about 5000 hours. That is, the use of the filament wire enables them to have a short using time.

Disclosure of Invention

Technical Problem

[12] It is, therefore, an object of the present invention to provide a heating apparatus using induction heating which heats an object indirectly by further having the heating body, and provide a heating body of a plate shape or a tube shape having a high heating efficiency and a strong structure.

[13] Moreover, another object of the present invention is to provide a luminous apparatus using induction heating having a luminous plate, and provide a material and a structure having the luminous plate of a surface light emitting for the luminous apparatus using induction heating. Technical Solution

[14] In accordance with an embodiment of the present invention, there is provided a heat ing apparatus using an induction heating, including: a power supply unit for supplying an alternating current; an induction coil for generating an alternating magnetic flux by the alternating current; and a heating body having a plate shape or a tube shape including a ferromagnetic body or a ferromagnetic alloy having a high heating efficiency for being heated by the alternating magnetic flux, wherein the heating body includes a material having a higher curie temperature than a maximum operation. [15] In accordance with another embodiment of the present invention, there is provided a luminous apparatus using an induction heating, including: a power supply unit for supplying an alternating current; an induction coil for generating an alternating magnetic flux by the alternating current; and a luminous plate for emitting a light and being heated by the magnetic flux.

Advantageous Effects

[16] As described above, a heating apparatus using induction heating in accordance with the present invention is used in various utilities since the heating apparatus is free from a limitation of a conductor by heating an installed heating plate. The heating apparatus has a simple power circuit and reduces a manufacturing cost because the heating apparatus doest not need to adjust an output power by detecting a permeability of a substance through the heating plate which is installed additionally.

[17] The heating apparatus using induction heating in accordance with present invention reduces power consumption by having a higher energy conversion efficiency than a conventional heating apparatus, and maintains a clean and comfortable indoor environment by not generating a noxious burned gas without consuming oxygen.

[18] And, the heating apparatus using induction heating in accordance with present invention uses a surface light emitting using a luminous plate instead of a conventional line shape, and improves a luminous efficiency. The heating apparatus has the luminous plate of various shapes requested by a consumer, prevents a disconnection caused by an evaporation generated in a conventional filament by using the luminous plate of a flat shape, and has a longer using time. Brief Description of the Drawings

[19] Fig. 1 shows a simple configuration of a conventional induction heating apparatus;

[20] Fig. 2 shows a simple configuration of a heating apparatus using induction heating in accordance with the present invention;

[21] Figs. 3 to 7 illustrate an induction coil and a heating plate for a heating apparatus using induction heating in accordance with the present invention;

[22] Figs. 8 to 12 illustrate a heating plate and a supporting plate for a heating apparatus using induction heating in accordance with the present invention;

[23] Figs. 13 to 15 illustrate an installation state of a heating plate for a heating apparatus using induction heating in accordance with the present invention;

[24] Figs. 16 and 17 illustrate a magnetic flux induction magnetic body for a heating apparatus using induction heating in accordance with the present invention;

[25] Fig. 18 illustrates a heating apparatus using induction heating in accordance with a first embodiment of the present invention;

[26] Figs. 19 and 20 illustrate a heating apparatus using induction heating in accordance with a secondary embodiment of the present invention;

[27] Figs. 21 and 22 illustrate a heating apparatus using induction heating in accordance with a third embodiment of the present invention;

[28] Fig. 23 illustrates a heating apparatus using induction heating in accordance with a fourth embodiment of the present invention;

[29] Fig. 24 illustrates a heating apparatus using induction heating in accordance with a fifth embodiment of the present invention;

[30] Figs. 25-27 illustrate a heating apparatus using induction heating in accordance with a sixth embodiment of the present invention;

[31] Figs. 28-31 illustrate a heating apparatus using induction heating in accordance with a seventh embodiment of the present invention;

[32] Figs. 32-34 illustrate a heating apparatus using induction heating in accordance with an eighth embodiment of the present invention; and

[33] Figs. 35 and 36 illustrate a heating apparatus using induction heating in accordance with a ninth embodiment of the present invention. Best Mode for Carrying Out the Invention

[34] An induction heating apparatus heats a conductor by an eddy current loss when an alternating magnetic flux is linked with a surface of the conductor. Especially, the induction heating apparatus heats the conductor by the eddy current loss and a hysteresis loss when the conductor is a magnetic body.

[35] The eddy current loss is generated by a joule heat, in other words, P=i *R, caused by an eddy current which is generated toward direction against to the alternating magnetic flux on a surface plane of the conductor located in the alternating magnetic flux. Here, P denotes a power, i denotes a current, and R denotes a resistance.

[36] Moreover, the hysteresis loss is generated from a magnetic body, and heats a heat by a rotation vibration of a magnetic molecule of the magnetic body in the alternating magnetic flux. That is, hysteresis loss presents an energy loss per a unit volume generated from a surface area which is covered with a hysteresis curve until the alternating magnetic flux is repeated once.

[37] Especially, the most important characteristic of the magnetic body heated by the induction heating is a curie temperature and non-permeability. The curie temperature is a temperature at which the magnetic body is changed into a paramagnet having non- permeability of about one by removing magnetization of the magnetic body by a thermal agitation when the magnetic body is heated at a higher temperature than the curie temperature. [38] Table 1

[39] Table 1 represents non-permeability and curie temperatures of various materials. As shown in table 1, the aluminum and copper as the paramagnet, and the copper as a diamagnetic substance have non-permeability of about one. But, the non-permeability of the nickel, cobalt, iron and 78permalloy as a ferromagnetic substance is much larger than one.

[40] Moreover, the cobalt of the ferromagnetic substances in the table 1 has the highest curie temperature of 2452⁰C. In general, a wanted curie temperature may be acquired from a ferromagnetic alloy which is alloyed by a ferromagnetic substance and other substances.

[41] Equation 1 represents an equation which acquires a skin depth δand skin resistance R .δ ac [42] MathFigure 1

δ= i 1

R ac= - σδ

[43] Where f denotes a frequency of a current, δrepresents electric conductivity, μrepresents permeability, and π represents the ratio of the circumference of a circle its diameter. The eddy current generated in a surface plane of a conductor by an alternating magnetic flux is attenuated along an exponential function in the conductor. The skin depth represents a depth at which current amplitude on the surface plane of the conductor is reduced to 1/e, that is, 36.7%, in the conductor. Since the eddy current is intensively distributed between the surface of the conductor and the skin depth, a resistance between the surface of the conductor and the skin depth is called as the skin resistance which is increased more as the skin depth is thinner as the equation one.

[44] The skin depth and skin resistance are varying with a value of non-permeability and a frequency such as the equation 1. A heating power generated between the surface plane and the skin depth of the conductor occupies 86.5% of a total power. A heating power of 80% of total power is generated between the surface plane and 0.8 times depth of the skin depth. Heating powers of 95% and 98% of total power are generated between the surface plane and 1.5 times depth and 3.1 times of the skin depth, respectively.

[45] Table 2

[46] Table 2 represents a skin depth and a skin resistance of 50KHz and 100KHz, an electric non-resistance of materials. Table 1 and table 2 uses values measured at 2O⁰C. [47] In details, there is a large difference between the aluminum having a skin depth of 364.17 μ and the 78permalloy having a skin depth of 2.85 μ which are acquired from the equation 1 in the frequency of 50KHz. Specially, the 78permalloy has a very thin skin depth and about 790 times larger surface resistance than the surface resistance of the aluminum as shown in the table 2.

[48] If the frequency is increased from 50KHz to 100KHz, the skin depth is decreased, and the skin resistance is increased. In general, an induction heating apparatus used in a home uses a frequency between 10KHz and 100KHz.

[49] Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

[50] Firstly, the same components in drawings have the same reference number. [51] The detailed description for a related prior technique is omitted to prevent a subject matter of the present invention from being non-obvious.

[52] As shown in Fig. 2, the heating apparatus and luminous apparatus using an induction heating in accordance with an embodiment of the present invention includes a power supply unit 10 which supplies an alternating current; an induction coil 20 which generates an alternating magnetic flux by the alternating current; a heating plate 50 which is heated by an eddy current generated by the alternating magnetic flux; and an insulating material 60 which protects the induction coil 20 from the heat generated in the heating plate 50.

[53] A flat type induction coil is used as the induction coil in Fig. 2.

[54] It is preferred that the heating plate 50 is 0.8times thicker than a skin depth to have a high heating efficiency by the alternating magnetic flux.

[55] Moreover, a solid plate is further included in the heating apparatus and luminous apparatus in Fig. 2. The solid plate is indirectly heated by the heating plate, and uses a barrel which stores water or a dish for a food.

[56] As shown in Fig. 3, at least one heating plate 50 or induction coil 20 is installed on a plurality of cells, respectively. An area heated from the heating plate 50 is easily changed by separately supplying a power to the induction coil 20.

[57] That is, as shown in Figs.3 and 4, at least two induction coils 20 and 21 are included in at least one heating plate 50. The power supply 10 adjusts a heated area of the heating plate 50 by selectively supplying a current to the induction coils 20 and 21.

[58] In more details, as shown in Fig. 3, another induction coil 21 of a doughnut shape may be included on an outer circumference of the induction coil 20 to change a heated area of the heating plates 50 and 51, or as shown in Fig. 4, another induction coil 21 may be included on a close position to the induction coil 20. It is preferred that the induction coil is covered with the area of the heating plate 50.

[59] In another embodiment, a plurality of heating plates 50 and 51, and induction coils

20 and 12 may be configured as shown in Figs. 5 and 6. Each of induction coils 20 and 12 may be installed on one of heating plates 50 and 51 respectively as shown in Figs. 5 and 6.

[60] Moreover, a combination of configurations in Figs 5 and 6 with configurations in

Figs 3 and 4 may be implemented. The power supply unit 10 changes a heated area by selectively supplying an alternating current to the induction coils 20 and 21. The heating plates 50 and 51, and induction coils 20 and 21 shown in Fig. 3 are illustrated as a rectangular shape but may have a circular shape or other shapes. In case that the induction coil is wound as a solenoid shape, the induction coil may have a shape as shown in Fig. 7. A plurality of induction coils and heating bodies of a tube shape may be configured.

[61] Further, it is notable that if an interval between the induction coil 20 and the heating plate 50 in Fig. 2 is increased, an alternating magnetic flux which is linked with the heating plate 50 is reduced, and a heating efficiency is reduced.

[62] Therefore, as shown in Fig. 2, the heating apparatus using induction heating of the present invention narrows an interval between the induction coil 20 and the heating plate 50, raises a heating efficiency, and protects the induction coil 20 from the heat generated from the heating plate 50 by further including an insulator material 60 between the induction coil 20 and the heating plate 50. The induction coil 20 may be protected by wrapping both sides of the induction coil with the insulator material.

[63] The induction coil 20 uses a litz wire, and the litz wire may be twisted to confine a generation of an eddy current.

[64] The heating plate 50 further includes a layer containing a corrosion resistance on a surface of the heating plate 50.

[65] Moreover, the heating plate 50 further includes a functional coating layer such as a ceramic coating to emit a negative ion, a far infrared ray or both of them together.

[66] It is preferred that the heating plate 50 is 0.8times thicker than a skin depth so that most magnetic fluxes are linked with the heating plate 50. However, it is preferred that the heating plate is not much thick since a heat is generated from only an opposite surface to the induction coil 20 of a surface plane of the heating plate 50, a heat is not generated from a necessary part for heating if the heating plate 50 is much thicker than the skin depth. In details, it is preferred that a depth of the heating plate 50 is less 3. ltimes thicker than the skin depth at which a heat having 98% of a total power is generated.

[67] Further, the heating plate 50 of the present invention may be composed of a ferromagnetic alloy or a ferromagnetic body, e.g. Fe, Co, Ni and Gd, to raise a heating power. In details, the ferromagnetic alloy may be composed of Ni alloy of Ni-Cr alloy, Fe alloy of alnico, Fe-Co alloy, stainless, permalloy, Co alloy, or Mn or Cr alloy. Components of Si, Al, C, Mn, Cu, Cr, Mo, V and W may be further included less than 10%.

[68] And, it is preferred that the heating plate 50 is a ferromagnetic body within a working range to have a high heating efficiency. Moreover, the heating plate 50 has a curie temperature close to a maximum operation temperature or an optimum operation temperature to prevent the heating plate 50 from being overheated.

[69] A luminous body of a plate or tube shape prevents from being overheated or maintains an optimum heating temperature by using a material having a curie temperature close to the maximum operation temperature and an optimum operation temperature.

[70] That is, if the temperature of the heating body is higher than the curie temperature, the heating body is changed into a paramagnet, a heating power is reduced, and a temperature of the heating body drops. If the temperature of the heating body drops again below the curie temperature, the heating body becomes the ferromagnetic body, and the heating power is increased. The temperature of the hating body is uniformly maintained at a close temperature to the curie temperature of the heating body.

[71] Moreover, the heating plate 50 may be composed of amorphous alloy to acquire wanted curie temperature and non-permeability. [72] In general, it is widely known that a hysteresis loss is increased when a frequency of the alternating magnetic flux is low, and an eddy current loss is increased when the frequency of the alternating magnetic flux is higher than a predetermined frequency in case that an induction heating is implemented in a ferromagnet having the same depth in state of changing a frequency of an alternating magnetic flux.

[73] The eddy current loss depends on non-linearity of non-permeability and various conditions. However, in case that the conductor is much thicker than a skin depth, it is known that a heating power of the eddy current is increased in proportion to a square root of the frequency such as the equation 2.

[74] MathFigure 2

P_e = k_eR_ac{Ni) ² ^ f{Ni) ²

[75] Where k denotes a proportional constant, N denotes the number of winding of the induction coil, i denotes a current, p denotes an electric non-resistance as 1/σ and f denotes a frequency. [76] Especially, since the heating power caused by the eddy current is proportion to the skin resistance, the skin resistance has a large influence on the hating power. As shown in table 2, the heating power of the iron using the induction heating is 137 times larger than the aluminum in a frequency of 50KHz. That is, a material having a very small skin resistance has a little heating power. [77] In other words, an electric non-resistance of a conductor must be high to acquire a high heating power by the eddy current loss. A general method for raising the electric non-resistance of the conductor is to use an alloy. [78] As described in Equation 2, it is preferred that the heating plate 50 is composed of a ferromagnetic alloy having a high non-permeability and a large non-resistance. [79] A heating power generated by a hysteresis loss is acquired by an equation 3 calculated by Steimetz. [80] MathFigure 3

[81] Where K denotes a hysteresis loss constant, and B denotes a magnetic flux of a h conductor surface. If a frequency of an alternating magnetic flux is low, the material having a large hysteresis loss instead of a large eddy current loss may be used as the heating plate. [82] The heating power using the induction heating generated by the eddy current loss and the magnetic hysteresis loss is increased according as a frequency of an alternating current provided to the induction coil is increased. Accordingly, if a higher frequency is used, a larger heating power is acquired and a volume of a power supply unit is reduced.

[83] As shown in Fig. 8, the heating plate of the present invention includes a heating layer 50b which is heated by the alternating magnetic flux, and a conducting layer 50a for conducting a heat of the heating layer 50b. Moreover, a plurality of heating layers 50b and conducting layers may be formed. Here, the heating layer 50b may be a ferromagnetic body or a ferromagnetic alloy having a high non-resistance and a high non- permeability to acquire a high heating efficiency. The conducting layer 50a uses a material which conducts a most heat generated from the heating layer 50b to reduce a heating loss. The conducting layer 50a is a conductor having a low resistance, a high thermal conductivity, and a thin depth. This structure may be used in a heating tube for a solenoid type induction coil.

[84] Further, Figs 9 to 11 illustrate a shape of a supporting plate 55 and a heating plate of a nonconductor material to support the heating plate 50 in case of using a flat type induction coil. As described in table 2, in case of 78permalloy having a high permeability, a supporting plate 55 for supporting a heating plate 50 may be further included since a skin depth is much thinner in case of an alternating current frequency of 50KHz.

[85] As shown in Figs 9 and 10, the heating plate 50 of the present invention may be located on a groove or over the supporting plate 55, and may be located inside the supporting plate for a convenience of a cleaning such as Fig. 11.

[86] And, Fig. 12 illustrates a shape of a heating tube 53 for a heating and the supporting tube 56 for supporting the heating tube in case of a solenoid type induction coil 20. The heating tube 53 has a pipe shape having a hollow, and the induction coil 20 is wound to an outer circumference of the supporting tube 56 located in an outset position.

[87] As shown in Fig. 12, in case of the solenoid type induction coil, the supporting tube

56 of non-ferromagnetic body and non-conductor for supporting the heating tube 53 may be further included if the heating tube 53 is much thin.

[88] The heating tube 53 is located inside the supporting tube 56, but the heating tube 53 may be located on an outer part of the supporting tube 56. This structure may be used of warming an air by passing the air to inside the heated heating tube.

[89] Figs. 13 to 15 illustrate a structure of a heating plate and a heating tube which are used as a heater which heats an air by adding a ventilator.

[90] As shown in Figs. 13 and 14, a plurality of heating plates and heating tubes having a different half diameter can be overlapped.

[91] As shown in Fig. 13, two heating plates 50c and 50d, which are opposite to each other, are supported by two supporting plates 55c and 55d. An induction coil for heating the heating plates 50c and 50d may be located on an external part of the supporting plates 55c and 55d.

[92] If one induction coil is installed on an external part of the supporting plates 55c and

55d, the heating plates is heated because an alternating magnetic flux generated from the induction coil is linked with two heating plates 50c and 50d. It is preferred that a total depth of the heating plates is 0.8 times thicker than a skin depth.

[93] As shown in Fig. 15, a supporting tube 56 may be located inside the heating tube

53. In this case, an induction coil is wound to an outer circumference of an outer tube 59 by further adding the outer tube 59 of a non-conductor material to an outer part of the heating tube 53.

[94] It is preferred that a material of the outer tuber 59 is non-conductor. Moreover, two heating tubes may be opposite to each other by locating the heating tube 53b and the supporting tube of Fig. 14 instead of the outer tube 59.

[95] This method may be used for heating an air in a heater, and raises a heating efficiency by increasing a heated air area.

[96] Further, two heating plates 50c and 50d may be heated by having the induction coils on both sides of an outer part of the supporting plates 55c and 55d of Fig. 13.

[97] Fig. 14 illustrates heating tubes 53a and 53b of a solenoid shape and supporting tubes 56a and 56b for supporting the heating tubes. An induction coil is located on an outer circumference of the supporting tube 56b of the outset side. Two heating tubes 56a and 56b, which are located inside the induction coil, are heated by the alternating magnetic flux generated from the induction coil.

[98] It is preferred that a depth of the heating tubes is adjusted so that the heating tubes are heated by permeating the alternating magnetic flux on two heating tubes 53a and 53b. If this method is used, a total heating area of the heating plate and the heating tube may be increased.

[99] As shown in Figs. 16 and 17, a ferromagnetic body for a magnetic flux shielding of a ferrite having a high resistance and permeability may be further included to prevent an electromagnetic wave interference generated from the induction coil 20. The reliability of products may be improved by reducing an electromagnetic interference noise and preventing a magnetic flux from being leaked.

[100] Figs. 16 and 17 illustrate a simplified shape of a ferromagnetic body for a magnetic flux shielding in case of using flat type and solenoid type induction coils.

[101] As shown in Fig. 16, an alternating magnetic flux 2 generated from an induction coil 20 is linked with a heating plate 50 so that an eddy current occurs on the heating plate 50 to be heated. The induction coil 20 covers ferromagnetic bodies 70 and 71 for a magnetic flux induction to shield the alternating magnetic flux 2. [102] Two ferromagnetic bodies 70 and 71 are configured in Fig. 16, but one ferromagnetic body may be formed by connecting the ferromagnetic bodies 70 and 71 to each other. Since a ferrite which is a metal oxide has a high electric resistance, the ferrite has a little power loss from an eddy current and is used as a ferromagnetic body for a magnetic flux shielding.

[103] Moreover, Fig. 17 illustrates ferromagnetic bodies 72 and 73 for a magnetic flux induction which may be used in a solenoid type induction coil 25. The ferromagnetic bodies 72 and 73 covers the induction coil 25 on both corners of a heating tube 53. The ferromagnetic bodies 70 to73 for the magnetic flux induction shown in Figs 16 and 17 may be manufactured in a rectangular rod.

[104] Contents mentioned above are applied to an embodiment of the heating apparatus or luminous apparatus using induction heating.

[105]

[ 106] (First embodiment)

[107] Fig. 18 illustrates an embodiment of an electric range, an electric fan, an electric grill, an electric oven, or a hot plate using an induction heating apparatus 100 of the present invention.

[108] The induction heating apparatus 100 includes a power supply unit 10 which generates an alternating current; a flat type induction coil 20 which generates an alternating magnetic flux by the alternating current; a heating plate 50 which is composed of a ferromagnetic body or a ferromagnetic alloy heated by an eddy current

I generated by the alternating magnetic flux 2; an insulator material 60 which protects the induction coil 20; an upper plate which supports the heating plate 50; and a cooking vessel which is indirectly heated by a heat generated in the heating plate 50.

[109] As shown in Fig. 18, an eddy current 1 occurs in the heating plate 50 by an alternating magnetic flux 2 generated by the induction coil 20, and the heating plate 50 is heated. A bottom plane 131 of a vessel 130 is heated by the generated heat.

[110] In the induction heating apparatus 100 of the present invention, a food is cooked by heating the vessel 130 through the heating plate 50. But, in a conventional induction heating apparatus, the vessel is heated by an eddy current as shown in Fig. 1.

[I l l] Thus, the vessel 130 used in the conventional induction heating apparatus shown in

Fig. 1 must be a conductor. However, since the induction heating apparatus 100 heats the vessel 130 by a heat generated from the heating plate 50, the induction heating apparatus 100 has a general purpose by using all sorts of vessels including a nonconductor material.

[112] In this case, an upper plate 240 instead of the supporting plate shown in Figs. 9 to

I 1 performs a supporting function for supporting the heating plate 50. The heating plate 50 may be inserted into a surface plane of the upper plate 240, a groove or inside the upper plate 240. Moreover, the heating plate is integrated with the upper plate 240.

[113] The induction heating apparatus 100 of the present invention further includes a temperature sensor and a temperature indication unit for measuring a temperature of the heating plate 50 so that a user recognizes the temperature of the heating plate 50 easily.

[114]

[115] (Second embodiment)

[116] Figs. 19 and 20 illustrate an electric pan or an electric rice-cooker using an induction heating apparatus in accordance with a secondary embodiment of the present invention.

[117] The induction heating apparatus 200 is composed of basic components as shown in

Fig. 18.

[118] In case of Figs. 19 and 20, a bottom plane 231 , a side plane 232, or both of them is heated and cooks a food by a heat generated from a heating plate 50.

[119] Here, an induction coil 20 shown in Fig. 19 has a flat shape or a spiral shape, but an induction coil 25 is wound to have a solenoid shape on an outer circumference of a heating tube 53, or an induction coil of a flat plate shape may be located on the side plane of the heating tube 53. That is, at least one heating tube is located on the side plane, and at least one induction coil has a flat plate of a zigzag shape or a spiral shape. A shape of the solenoid used as the side plane in all embodiments may be replaced by a flat plate shape. When the induction coil of the flat plate shape is located on the side plane, a plate of a various shape such as the flat plate, a bending plate, or a recessed plate may be used as the heating plate.

[120]

[121] (Third embodiment)

[122] Figs. 21 and 22 illustrate an induction heating apparatus 300 in accordance with a third embodiment of the present invention.

[123] The induction heating apparatus 300 shown in Fig. 21 is composed of basic components shown in Fig. 18, and a shelf 330 is heated by a heat generated from a heating plate 50.

[124] The heating plate 50 heats and cooks a food by heating a bottom plane 330 of the shelf through a thermal conduction or convection. Moreover, a solenoid type induction coil 20 and a heating tube 53 are further included in a side plane shown in Fig. 22. The solenoid type induction coil may be formed as a flat plate type as described in the third embodiment of the present invention.

[125] The induction heating apparatus 300 of the present invention may cook a food through a warm air by further having a ventilator. Moreover, the induction heating apparatus 300 may cook a food through a steam by generating the steam. [126]

[ 127 ] (Fourth embodiment)

[128] Fig. 23 illustrates an induction heating apparatus in accordance with a fourth embodiment of the present invention. [129] The induction heating apparatus 400 may be applied to an electric boiler, an electric instantaneous water heater, a humidifier, or an electric port for boiling water. The induction heating apparatus 400 has the same basic component shown in Fig. 18, and heats the water by heating a water tank or a vessel having the water with a heat generated from a heating plate 50. [130] As shown in Fig. 23, the heating plate 50 is heated by an alternating flux generated from an induction coil 20. The water is warmed by heating the bottom plane 431 of the vessel 430 or the water tank with the heat generated from the heating plate 50. [131] As shown in Fig. 23, the induction coil of a flat plate type and the heating plate are used, but an induction coil of a solenoid type or a flat plate type may heat a side plane. [132] The electric instantaneous water heater of the present invention may be used for a shower, a sink, or a bath. [133]

[134] (Fifth embodiment)

[135] An induction heating apparatus of the present invention shown in Fig. 24 illustrates an automated heating method of a food or an object. As shown in Fig. 24, moving unit

510, which transfers a vessel having the food or object, is further included in the basic components shown in Fig. 18. [136] The vessel transferred by the moving unit 510 is heated by a heat generated from the heating plate 50 for a predetermined time. The moving unit shown in the Fig.2 is composed of a rotator 510 having a circular shape and a supporting bar 520 for supporting a vessel 530. [137] In details, the vessel 530 is put on both sides of the supporting bar 520 and the heating plate 50 heats the vessel 530. In another embodiment, the heating plate may be moved or the heating plate and an object to be heated may be moved by the moving unit 510. [138] A ventilator is further included in the induction heating apparatus shown in Fig. 24, and the heating plate 50 heats an air. A food or an object is dried by the heated air.

Moreover, the heating plate 50 may heat water and generate a steam. The food or object may be heated by the steam. [139]

[ 140] (Sixth embodiment)

[141] An induction heating apparatus 600 of the present invention shown in Figs. 25 to 27 includes a power supply unit 10, an induction coil 20, a heating plate 50, a magnetic substance, and an insulated material 60. The power supply unit 10 generates an alternating current. The induction coil 20 uses a litz line which generates an alternating magnetic flux by the alternating current. The heating plate 50 is heated by the magnetic flux and is composed of a ferromagnetic body or a ferromagnetic body alloy for improving a heating efficiency. The magnetic body has a high resistance and a high permeability of a ferrite for preventing an electromagnetic interference. The insulated material 60 protects the induction coil 20 from the heat generated in the heating plate 50.

[142] Since the heating plate 50 is 0.8 times thicker than a skin depth, most magnetic fluxes are linked with the heating plate 50 and the heating plate 50 is made of a material having a higher curie temperature than a maximum operation temperature. The heating plate 50 is composed of at least one heating plate or induction coils to change a heated area. A power is divided into and supplied to each of the induction coils. The magnetic body is not shown for convenience of description in Figs. 25 to.

[143] The induction heating apparatus 600 of the present invention shown in Figs. 25 to

27 uses the heating plate 50 which is heated by an induction heating instead of a conventional heating body, and uses a radiation heat generated from the heating plate 50. That is, a conventional heater uses a heating line of a line shape, but the heating plate 50 uses a surface heating body.

[144] Accordingly, since the heating plate 50 radiates more heat per unit area than a conventional heating line, a size of the heating plate 50 may be reduced, or a probability of an error caused by a disconnection is lowered.

[145] Moreover, as shown in Figs. 26 and 27, in case of further including a ventilator 610, an indoor temperature is adjusted by penetrating a cool air between heated heating plates or heating tubes, and ejecting the heated air 630. The heating plate 50 or the heating tube 53 may be supported by a supporting plate 55 as shown in Figs. 9 to 12.

[146] Further, the heating plate and the heating tube may have the same structure shown in the Fig. 8. If the structure shown in Figs 13 to 15 is used as a heating body, a heated area and a heated efficiency may be largely increased. A flat plate type induction coil is shown in Figs. 25 to 27, and a heating tube and a solenoid type induction coil shown in Figs. 14 and 15 may be used.

[147]

[148] (Seventh embodiment)

[149] Figs. 28-31 illustrate an induction heating apparatus 700 in accordance with a seventh embodiment of the present invention.

[150] The induction heating apparatus 700 may be used as an electric heater of a motor fan type, and a heating plate 50, which is heated by an induction heating instead of a conventional heating line, is used as a heating body. The induction heating apparatus 700 further includes reflective plates 710 and 720 in basic components shown in Figs. 25 to 27.

[151] In details, the induction heating apparatus 700 of the present invention further includes a flat plate type heating plate 50 which is heated by an induction heating instead of a motor fan type heater using a conventional heating line, and further includes a front reflective plate 710 of a vessel shape which is protruded on a central part of a front protection net 780 confronted to the heating plate 50. A radiation heat

701 generated from the heating plate 50 is reflected by the front reflective plate 710. A radiation heat 701 reflected by a rear reflective late 720 of a depressed shape is supplied to a user. It is preferred that a material of the reflective plates 710 and 720 are a conductor.

[152] Moreover, as shown in Fig. 30, the induction heating apparatus 700 further includes a ventilator 730, and radiates a heat from the heating plate 50. The induction heating apparatus 700 heats an air, which inflows from an inlet, with the ventilator 730 and may adjust an indoor temperature by the heated air 702.

[153] Further, as shown in Fig. 31, the induction heating apparatus 700 may adjust an indoor temperature with a heated air by further including a heating plate 51, an induction coil 21 and a ventilator 630. The heating plate 51, the induction coil 21 and the ventilator may be located on a head part of the electric motor type heater or the other part.

[154]

[155] (Eighth embodiment)

[156] Figs. 32-34 illustrate an induction heating apparatus 800 in accordance with an eighth embodiment of the present invention.

[157] The induction heating apparatus shown in Figs. 32 to 34 includes the same basic components with the induction heating apparatus 700 shown in Figs. 28 to 31. As shown in Figs. 32 to 34, a radiation heat 801 generated from a heating plate 50 is reflected from a first reflective plate 810 to a second reflective plate 820, and the reflected radiation heat is supplied to a user.

[158] As shown in Fig. 34, the reflective plates 810 and 820 may have a recessed shape or a protruded shape.

[159]

[160] (Ninth embodiment)

[161] A luminous apparatus using an induction heating which is different from the induction heating apparatus mentioned above embodiments will be described below.

[162] A conventional luminous apparatus emits a light by enabling a current to flow on a filament, but an induction heating luminous apparatus uses a luminous plate which emits a light by being heated with an alternating magnetic flux. The induction heating luminous apparatus of the present invention emits a light of a flat shape different from a conventional line luminous body using tungsten.

[163] The induction heating luminous apparatus 900 of the present invention includes a power supply unit 910, an induction coil 920, a luminous plate 950, and an insulation unit 960. The power supply unit supplies an alternating current. The induction coil 920 generates an alternating magnetic flux by the alternating current. The luminous plate 950 is heated and emits a light by the alternating magnetic flux. The insulation unit 960 protects the induction coil 920 from the heat generated from the luminous plate 950.

[164] The induction heating luminous apparatus 900 may further includes a glass tube 930 which is made of quartz or a glass. [165] In case that the luminous plate 950 is much thin and a frequency of an alternating current supplied from the power supply unit 910 is much high, the induction heating luminous apparatus 900 further includes a supporting structure for supporting the luminous plate 950. The supporting structure and the luminous plate may have the same structure with the structure shown in Figs. 9 and 10. Further, the supporting structure may be a part of the glass tube.

[166] Each of the luminous plate 950 and the induction coil 920 is configured as shown in Fig. 3, and a power may be divided into and be supplied to the induction coil 920 so that a light emitted area of the luminous plate 950 is easily changed.

[167] It is preferred that the insulation unit 960 is manufactured to be thin so that most alternating magnetic flux generated in the induction coil 920 is linked with the luminous plate 950 and a high light emitting efficiency is acquired by narrowing an interval between the induction coil 920 and the luminous plate 950. A thin reflective plate, which uses an air as an insulated material and reflects a radiation heat, may be included in the insulation unit 960.

[168] The induction heating luminous apparatus 900 may shield a magnetic flux to cover the induction coil 920 with an outer part of the magnetic body by further having the magnetic body for a magnetic flux shielding of a ferrite for preventing an electromagnetic interference.

[169] Table 3

[170] Table 3 shows a melting point of a tungsten and representative ferromagnetic bodies. A melting point of the tungsten is 3422⁰C, and a melting point of the cobalt is 1495⁰C. The cobalt has a low melting point for being used as a luminous plate since an incandescent lamp acquires an optimum white light at 2500⁰C - 2700⁰C. Accordingly, it is preferred that the luminous plate 950 is composed of tungsten or tungsten alloy.

[171] The luminous plate 950 may be a ferromagnetic body to acquire high heating efficiency. However, it is preferred to raise a curie temperature by being alloyed with a metal having a high melting point since a curie temperature of the ferromagnetic body is much lower than about 2500⁰C at which an optimum white light may be acquired. A material of the luminous plate 950 may be composed of an alloy of tungsten and a ferromagnetic body of steel, nickel and cobalt. Tungsten alloy may further include Si, Al, C, Mn, Cu, Cr, Mo, V and W.

[172] It is preferred that the luminous plate 950 is maintained as a ferromagnetic body within an operation temperature. Moreover, the luminous plate 950 may prevent an overheat or maintain an optimum a light emitting temperature by using a material having a maximum operation temperature or a curie temperature near to an optimum operation temperature for a light emitting. A principle for maintaining a uniform temperature is the same with a heating body for radiating a heat mentioned above.

[173] A coating of tungsten having a high melting point may be formed on a surface of the luminous plate 950 as shown in Fig. 8 to reduce evaporation at a high temperature.

[174] The luminous plate 950 may further include aluminum, a silicon oxide and a potassium oxide to prevent the luminous plate 950 from being changed.

[175] It is preferred that most magnetic fluxes are linked with the luminous plate 950 by forming the luminous plate 0.8 times thicker than a skin depth.

[176] An oxide of barium for emitting a thermo-electron at a high temperature may be further included in a surface of the luminous plate 950, or a fluorescent material may be further spreaded on an inner wall of the glass tube 930.

[177] The luminous plate 950 has a flat shape, and may have a long plate shape, a circular shape, or a heart shape depending on a purpose. Moreover, the luminous plate may be manufactured to be recessed or protruded depending on the purpose.

[178] A material for emitting an electron may be further included in the luminous plate

950 to purify an air or a smell.

[179] Litz line is used as the induction coil 920 and may be twisted to prevent an eddy current from being generated.

[180] The power supply unit 910 may have an inverter circuit using a semiconductor

(MOSFET, IGBT) for a high efficiency, an ultra miniature and a lightening. Moreover, the power supply unit 910 may use a resonant type power having a high efficiency.

[181] The power supply unit 910 may have a high frequency to reduce a volume of the power supply and raise a supply power. In details, the power supply unit 910 may have a higher frequency than 10KHz.

[182] The induction heating luminous apparatus 900 of the present invention may be manufactured as a fluorescent lamp or an incandescent lamp which are capable of being exchanged as shown in Figs 35 and 36. The incandescent lamp and the fluorescent lamp include the glass tube 930 or the luminous plate 950, or further include the induction coil 920 or the insulation unit 960 in the glass tube 930 and the luminous plate 950.

[183] The incandescent lamp shown in Fig. 35 includes the glass tube 930, the luminous plate 950, the insulation unit 960 and the induction coil 920. The power supply unit 910 is installed on an outer part of the incandescent lamp. Moreover, the power supply unit 910 may be installed in the incandescent lamp. The fluorescent lamp shown in Fig. 36 includes the glass tube 930 and the induction coil 920. The other components are installed on an outer part of the fluorescent lamp. Moreover, the insulation unit 960 shown in Fig. 35 may be included in the incandescent lamp, an outer side of the incandescent lamp, or both of them.

[184] An intrinsic color is emitted by injecting a gas having a small quantity into the inside of the glass tube 930. The gas is argon, nitrogen, krypton, sodium, or mercury.

[185] The induction heating luminance apparatus 900 of the present invention further includes a reflective plate 970 for reflecting a light generated in the luminous plate 950 on an outer of the incandescent lamp or inside the incandescent lamp.

[186] While the present invention has been described with respect to certain preferred embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the spirits and scope of the invention as defined in the following claims.

Claims

[1] A heating apparatus using an induction heating, comprising: a power supply unit for supplying an alternating current; an induction coil for generating an alternating magnetic flux by the alternating current; and a heating body having a plate shape or a tube shape including a ferromagnetic body or a ferromagnetic alloy having a high heating efficiency for being heated by the alternating magnetic flux, wherein the heating body includes a material having a higher curie temperature than a maximum operation temperature. [2] The heating apparatus using an induction heating as recited in claim 1, further comprising: a solid plate for being indirectly heated by a heating plate of the heating body, wherein the heating plate is one selected from a group of a flat plate, a recessed plate, a protruded plate and a bending plate. [3] The heating apparatus using an induction heating as recited in claim 1, wherein the heating body and the induction coil are divided into a plurality of cells, and a heated area of the heating body is varied according to a selective power supply of the power supply unit. [4] The heating apparatus using an induction heating as recited in claim 1, further comprising: a supporting structure having a plate shape or a tube shape of a non-conducting material for supporting the heating body; and an upper plate having a plate shape, wherein the heating body is fixed on the supporting structure or the upper plate. [5] The heating apparatus using an induction heating as recited in any one of claim 1 to 4, wherein the heating body is 0.8 times thicker than a skin depth to acquire a high heating efficiency by linking most magnetic flux with the heating plate. [6] The heating apparatus using an induction heating as recited in claim 5, wherein in case that the heating body is a heating plate, the heating plate has a plurality of folded plates. [7] The heating apparatus using an induction heating as recited in claim 5, wherein in case that the heating body is a heating tube, the heating tube has a plurality of folded tubes of a circular shape having a different diameter. [8] The heating apparatus using an induction heating as recited in claim 5, wherein a ferromagnetic body alloy includes Si, AL, C, Mn, Cu, Cr, Mo, V and W elements of which contained quantity is less than 10%. [9] The heating apparatus using an induction heating as recited in claim 5, wherein the heating body includes: at least one heating layer for heating; and at least one conductive layer for conducting a heat generated from the heating layer. [10] The heating apparatus using an induction heating as recited in claim 9, wherein the heating layer includes a ferromagnetic and a ferromagnetic alloy having a high resistance and a high non-permeability, and the conducting layer includes a conductor of a non-magnetic body and a low resistance. [11] The heating apparatus using an induction heating as recited in claim 5, further comprising: at least one magnetic body of a ferrite material having a high resistance and a high permeability for a magnetic flux shielding for preventing an electromagnetic interference caused by an electromagnetic wave generated from the induction coil. [12] The heating apparatus using an induction heating as recited in claim 5, further comprising: an insulation material for protecting the induction coil from a heat generated from the heating body. [13] The heating apparatus using an induction heating as recited in claim 5, wherein the induction coil uses litz line, and the litz line is twisted to prevent an eddy current from being generated. [14] The heating apparatus using an induction heating as recited in claim 5, wherein the heating body includes an amorphous alloy to acquire a wanted curie temperature and a non-permeability. [15] The heating apparatus using an induction heating as recited in claim 5, wherein the heating body further includes a functional coating such as a ceramic coating which emits a far infrared ray, a negative ion, or both of them. [16] The heating apparatus using an induction heating as recited in claim 5, further comprising: a ventilator for heating an air by the heated heating plate. [17] The heating apparatus using an induction heating as recited in claim 5, wherein the heating body heats a food or water, or generates a steam by heating the water. [18] The heating apparatus using an induction heating as recited in claim 5, further comprising: a moving unit for moving the heating body or an object or a food to be heated, wherein the moving object and food is heated by a heat or a steam generated from the heating body. [19] The heating apparatus using an induction heating as recited in claim 5, wherein a radiation heat generated by the heating body is supplied to a user, or an air is heated by the heating body and an indoor temperature is adjusted by the heated air. [20] The heating apparatus using an induction heating as recited in claim 19, further comprising: at least one reflective plate for reflecting the radiation heat generated from the heating body, wherein the reflective plate is a flat type, a recessed type, or a bending type. [21] A luminous apparatus using an induction heating, comprising: a power supply unit for supplying an alternating current; an induction coil for generating an alternating magnetic flux by the alternating current; and a luminous plate for emitting a light and being heated by the magnetic flux. [22] The luminous apparatus using an induction heating as recited in claim 21, wherein the luminous plate and the induction coil are divided into a plurality of cells, and a luminous area is varied according to a selective power supply of the power supply unit. [23] The luminous apparatus using an induction heating as recited in claim 21, further comprising: a supporting structure for supporting the luminous plate in case that a frequency of the alternating current is high and the luminous plate is thin, wherein the luminous plate is supported by the supporting structure. [24] The luminous apparatus using an induction heating as recited in 21, further comprising: an insulation unit for protecting the induction coil from the heat generated from the luminous plate. [25] The luminous apparatus using an induction heating as recited in claim 21, further comprising: a magnetic body of a ferrite material for a magnetic flux shielding for preventing an electromagnetic interference generated from the induction coil. [26] The luminous apparatus using an induction heating as recited in claim 21, wherein a material of the luminous plate is one of tungsten, tungsten alloy having a high melting point, a ferromagnetic body alloy having a high light emitting efficiency, and an alloy of a ferromagnetic body and tungsten. [27] The luminous apparatus using an induction heating as recited in claim 26, wherein the luminous plate has a material having a higher curie temperature than or a near temperature to a maximum operation temperature for emitting a light to prevent an overheat of the luminous plate or maintain an optimum light emitting temperature. [28] The luminous apparatus using an induction heating as recited in claim 26, wherein the luminous plate is 0.8 times thicker than a skin depth so that most magnetic fluxes are linked with the luminous plate. [29] The luminous apparatus using an induction heating as recited in claim 26, wherein the luminous plate further includes a thin tungsten coating on a surface plane of the luminous plate to reduce evaporation at a high temperature. [30] The luminous apparatus using an induction heating as recited in claim 26, wherein the luminous plate has a flat type, and has a long plate, a circular plate, or a heart shape depending on a purpose. [31] The luminous apparatus using an induction heating as recited in claim 21, wherein the induction coil uses a litz line, and the litz line is twisted to prevent an eddy current from being generated. [32] The luminous apparatus using an induction heating as recited in claim 21, wherein the power supply unit includes an inverter circuit using a semiconductor having a high efficiency, an ultra miniature, a lightening and a low price. [33] The luminous apparatus using an induction heating as recited in claim 21, further comprising: a reflective plate for reflecting a light. [34] The luminous apparatus using an induction heating as recited in any one of claims 21 to 33, further comprising: a glass tube made of a quartz material or a glass material. [35] The luminous apparatus using an induction heating as recited in claim 34, wherein the glass tube further includes a gas for protecting the luminous plate or supporting a light emitting. [36] The luminous apparatus using an induction heating as recited in claim 34, wherein the luminous plate further includes a metal oxide for emitting a thermo- electron on a surface plane at a high temperature, and a fluorescent material is further spreaded on a surface plane of the glass tube.