KR101406285B1 - Dielectric Heating Apparatus and Dielectric Heating Method of using the same - Google Patents

Abstract

The present invention relates to a ceramic heating element composition, a dielectric heating type heating device and a dielectric heating type heating method using the same, the method comprising the steps of: (1) packaging a ceramic heating element composition with heat resistant fibers; (Step 2) of putting the ceramic heating element composition packaged with the heat-resistant fiber into a heating container of a dielectric heating type heating device; Filling the heating container with thermal oil (step 3); Applying power to the magnetron (step 4); Irradiating the ceramic heating element composition and the heat generating container with microwave to generate heat (step 5); And (6) heat-conducting the heat generated from the ceramic heating element composition and the heating container to the heating medium oil; And is used as a ceramic heating element composition by mixing graphite with any one selected from the group consisting of silicon carbide, silicon nitride, and polysilicon. In addition to the ceramic heating element composition, The effect of reducing the occurrence of hot spots and the heat storage time can be improved by allowing the ceramic heating element composition to exothermically react in the thermal oil oil. Heat exchanger can be used for a heater, a hot air fan, a water heater, and a heating device for an electric car.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a dielectric heating device and a dielectric heating method using the dielectric heating device,

The present invention relates to a ceramic heating element composition, a dielectric heating type heating device and a dielectric heating type heating method using the same, and more particularly, to a ceramic heating element composition capable of reducing the occurrence of hot spots and increasing a heating rate and a heat storage time , A dielectric heating type heating apparatus and a dielectric heating type heating method using the same.

Generally, a boiler is a device for generating hot water or high temperature steam by heating water in a closed container and supplying it to a necessary place, and various types are used for generating hot water or steam.

Conventional conventional boilers include a container for containing a material to be heated and a burner so as to generate steam and hot water by heating the heat exchanger using a heat source generated from the burner.

However, since conventional boilers use energy of combustion because they use combustion heat, most of them use fossil fuel as a heat source, so there is a problem of polluting the atmosphere due to the emission of pollutants, and due to limited resources, There is a drawback to doing so.

Therefore, it is required to develop a boiler with low pollution, low cost, and excellent thermal efficiency.

Korean Patent Publication No. 10-2012-0001443 (2012.04.04) discloses an electronic boiler using microwave. The electronic boiler is advantageous in that it can heat water using a microwave generated by a magnetron and can produce hot water using a large amount of heat energy generated from the microwave. However, hot spots are generated, And there is a problem that it takes a long time to raise the initial temperature.

The present inventors have developed a ceramic heating element composition, a dielectric heating type heating device, and a dielectric heating type heating method using the same, which can reduce the occurrence of hot spots and increase a heating rate and a heat storage time.

KR 10-2012-0001443 A 2012.01.04.

SUMMARY OF THE INVENTION An object of the present invention is to provide a ceramic heating element composition, a dielectric heating type heating device, and a dielectric heating type heating method using the ceramic heating element composition, which can reduce the occurrence of hot spots and increase a heating rate and a heat storage time.

In order to achieve the above object, the present invention provides the following means.

The present invention relates to a ceramic heating element, characterized by comprising 10 to 50 parts by weight of graphite per 100 parts by weight of any one selected from the group consisting of silicon carbide, silicon nitride and polysilicon. Lt; / RTI >

The silicon carbide is 50 to 500 μm, the silicon nitride is 50 to 500 μm, the polysilicon is 50 μm to 2 mm, and the graphite is 1 to 100 μm in size.

Wherein the binder further comprises 10 to 20 parts by weight of a binder with respect to 100 parts by weight of the ceramic heating element composition, wherein the binder is a silicone adhesive.

Further, the present invention comprises an external resonant chamber, an internal resonant chamber located inside the external resonant chamber, and a heat generating vessel located in the internal resonant chamber; Wherein the heat generating container is filled with the ceramic heating element composition of claim 1 and heat medium oil; A heat insulating material is formed between the external resonance chamber and the internal resonance chamber to block heat outflow to the outside; A waveguide as a propagation path for transmitting the microwave generated in the magnetron to the ceramic heating element composition; Wherein the heating container and the ceramic heating element composition generate heat in response to a microwave transmitted through the waveguide and heat transfer to the heating oil is provided.

A heat exchanger may be provided in the heat-generating container to heat-exchange the heat transferred to the heat medium oil to the heat-transfer fluid passing through the space inside the heat-exchanger.

The heat-generating container is characterized by using borosilicate glass.

Further, the present invention provides a method of manufacturing a ceramic heater, comprising the steps of: (1) packaging the ceramic heating element composition with heat-resistant fibers; (Step 2) of putting the ceramic heating element composition packed with the heat-resistant fiber into the heating container of the dielectric heating type heating device; Filling the heating container with thermal oil (step 3); Applying power to the magnetron (step 4); Irradiating the ceramic heating element composition and the heat generating container with microwave to generate heat (step 5); And (6) conducting heat from the ceramic heating element composition and the heat generating container to heat medium oil; And a dielectric heating type heating method using the dielectric heating type heating device.

In the step 3, 5 to 30 parts by weight of the ceramic heating element composition is added to 100 parts by weight of the thermal oil.

The thermal oil is characterized in that either paraffin oil or alkylbenzene oil is used.

The dielectric heating type heating method according to the present invention uses graphite as a ceramic heating element composition by mixing graphite with any one selected from the group consisting of silicon carbide, silicon nitride, and polysilicon. In addition to the ceramic heating element composition, The effect of reducing the generation of hot spots and the heat storage time can be increased by allowing the ceramic heating element composition to exothermically react in the heat medium oil.

In the present invention, the heat energy of the heat medium oil is heat-exchanged with air or water to be used for a heater, a hot air fan, a water heater, and a heating device for an electric vehicle.

1 is a schematic cross-sectional view of a dielectric heating heating apparatus 100 according to an embodiment of the present invention.
2 is a front perspective view of a dielectric heating heating apparatus 200 according to another embodiment of the present invention.

Hereinafter, the present invention will be described in detail.

The microwave can be defined as an electromagnetic field wave having a wave ranging from 300 MHz to 300 GHz in a frequency range from 1 m long to 1 mm smaller. The development of microwave frequencies during World War II with a high-definition radar has made much progress and has developed a magnetron valve that is a high power microwave generator with excellent efficiency. Since the war, microwaves in the low frequency range have begun to be used in homes and industries for heating purposes. Today, industrial microwave heating systems are used in many fields such as the food industry, thawing, vacuum drying, pasteurization, disinfection, have.

The main mechanism of dielectric heating by microwaves can be divided into two. The first is the induction heating in which the heat generated by the resistance of the dielectric in the microwave electric field raises the temperature when the dielectric behaves like a weak electrical conductor with a measurable finite resistivity in direct current (DC) to be.

The second is dielectric heating. In many dielectrics, the bipolar components of a molecule are electrostatically coupled to the microwave field. Since the microwave changes with alternating current, the dipoles will be relocated back again in time. At such a microwave frequency, when a constant state of mechanical vibration is maintained, heat is generated by friction between molecules.

In the dielectric heating principle, it is true that as the microwave frequency increases, the amount of frictional heat generated by the increase in the number of relocation of the dipole increases. However, there is actually a mechanical resonance between the molecules in the microwave region, A maximum point of absorption occurs. The genetic data of the material are used as important data to obtain the predicted value of power density or the depth of microwave penetration according to electric field stress and material as shown in the dielectric heating equation. Each chemical compound has a well defined spectral response in the microwave frequency domain, and microwave spectroscopy is well known for its analytical techniques for exploiting this phenomenon.

The present invention utilizes the principle of heating by microwaves and provides a ceramic heating element composition that generates heat by using microwaves.

The ceramic heating element composition according to the present invention comprises 10 to 50 parts by weight of graphite per 100 parts by weight of any one selected from the group consisting of silicon carbide (SiC), silicon nitride, and polysilicon. do.

If graphite is contained in an amount of less than 10 parts by weight based on 100 parts by weight of any one selected from the group consisting of silicon carbide (SiC), silicon nitride and polysilicon, And when the amount of the component (B) exceeds 50 parts by weight, the density increases and the heat medium oil rapidly raises the temperature, thereby degrading the heat medium oil, thereby deteriorating the performance of the heat medium oil.

When the silicon carbide alone is used, it takes a long time to raise the temperature at the initial stage. Therefore, the present invention is characterized in that graphite is mixed and the initial temperature rise time is shortened.

The graphite is excellent in exothermic property and is used as a high-temperature exothermic material because it generates heat at a high temperature within a few minutes and has excellent heat conduction.

It is also possible to use carbon black or carbon nanotube (CNT) instead of the graphite.

The size of the silicon carbide is preferably 50 to 500 μm, the silicon nitride is 50 to 500 μm, the polysilicon is 50 to 2 mm, and the graphite is 1 to 100 μm. hot spot) may occur.

The ceramic heating element composition according to the present invention does not need to be fired and can be used in the form of powder or granules. 10 to 20 parts by weight of a binder is mixed with 100 parts by weight of the ceramic heating element composition to prepare a powdery or granular composition It may be solidified and molded into a plate. The binder is preferably a silicone adhesive, and the silicone adhesive is not particularly limited. If less than 10 parts by weight of the binder is mixed with 100 parts by weight of the ceramic heating element composition, solidification may not be performed well, and mixing of more than 20 parts by weight may affect the heat generation.

Further, the present invention is characterized by using borosilicate glass as a heat-generating vessel. When the microwave is irradiated, the heating element composition not only generates heat but also generates heat in the borosilicate glass, thereby further increasing the heating rate.

Conventionally, a hot spot is generated due to the exothermic reaction of a ceramic heating element in the air, and when a hot spot is generated, there is a problem that the case metal is damaged due to a high temperature instantaneously.

The present invention is characterized in that the ceramic heating element composition is placed in the lower part of the heating container or suspended in a granular form from top to bottom, and then the heating container is filled with 75 to 85% of the container capacity and the microwave is irradiated, And the generation of hot spots is reduced because the ceramic heating element generates heat.

The thermal oil is not particularly limited, but paraffin oil or alkylbenzene oil can be used.

The present invention is characterized in that heat is stored for a long time by heating a ceramic heating element composition using a microwave generated by a magnetron and transferring the generated heat energy to the heating medium oil.

Next, a dielectric heating type heating apparatus 100 using the ceramic heating element composition of the present invention will be described with reference to FIG.

A dielectric heating type heating apparatus 100 using a ceramic heating element composition according to the present invention includes a ceramic heating element composition 10, a heating medium oil 20, a magnetron 30, a heating container 40, an internal resonance chamber 50, 60 and an external resonance chamber 70.

The magnetron 30 generates a microwave when a predetermined voltage is applied to the magnetron 30 and the microwave is irradiated into the heating container 40 and the heating container 40 through the waveguide 35. The waveguide 35 is a transmission path for transmitting the microwave generated from the magnetron 30 to the heating container 40 and the ceramic heating element composition 10.

The ceramic heating element composition 10 may be packed in heat-resistant fibers, then placed under the heat-generating container 40, or suspended from top to bottom. When the ceramic heating element composition 10 is packed with heat-resistant fibers, the occurrence of hot spots during an exothermic reaction can be suppressed. The ceramic heating element composition 10 generates heat in response to microwaves generated in the magnetron 30. The ceramic heating element composition 10 comprises 10 to 50 parts by weight of graphite per 100 parts by weight of silicon carbide, silicon nitride and polysilicon. . 10 to 20 parts by weight of a binder may be further added to 100 parts by weight of the ceramic heating element composition, and the mixture may be solidified to be formed into a plate. The binder may be a silicone adhesive. The heating temperature and the heating time of the ceramic heating element composition 10 can be adjusted.

The heat-generating container 40, the internal resonance chamber 50, and the external resonance chamber 70 may have various shapes, and may have a hexahedral shape or a cylindrical shape.

It is preferable to use borosilicate glass that generates heat when the microwave is irradiated to the heating container 40. The upper part of the heating vessel 40 is sealed by a heating vessel lid 42 and the heating vessel lid 42 is provided with a gas supply port 45 so that the heating oil is supplied to the heating vessel 40 . The heating oil vessel 40 is connected to the oil feed pipe 46 and the oil circulation pipe 47. The heating oil oil 20 to which the heat energy generated from the ceramic heating element composition 10 is transferred is heat exchanged through the oil feed pipe 46 And the heat medium oil 20 having passed through the heat exchanger is filled into the heat generating vessel 40 through the ring tube 47 again. The heat-resistant packing (49) is provided at the junction between the heat-generating container (40) and the heat-generating container lid (42) so that the heat-oil oil (20) The ceramic heating element composition 10 and the heating medium oil 20 are placed in the inner space of the heating container 40 in the inner space and the ceramic heating element composition 10 and the heating medium oil 20 are formed in the lower space An air cock 43 for regulating the pressure of the air layer is provided on the upper side so as to intercept the flow of air.

Wherein the resonance chamber has a dual structure of an internal resonance chamber 50 and an external resonance chamber 70 and the internal resonance chamber 50 accommodates the heating chamber 40, And a heat insulating material 60 is filled between the internal resonant chamber 50 and the external resonant chamber 70. The external resonance chamber cover 72 is double-walled and filled with a heat insulating material 60 therein. The internal resonant chamber 50 is made of stainless steel in order to increase the yield of microwave heating. A heat resistant packing (59) is provided at the junction of the internal resonant chamber (50) and the internal resonant chamber lid (52) so as to prevent microwave leakage. The heating chamber 40 is spaced apart from the internal combustion chamber 50 by a predetermined distance. The internal combustion chamber 50 is sealed to form a low pressure and an air cock is formed in the internal combustion chamber cover 52. If the pressure due to heat is exceeded, .

According to the present invention, the magnetron 30 is not operated under the control of a control unit (not shown), so that the temperature of the ceramic heating element composition 10 can be prevented from rising above a predetermined temperature.

Further, the present invention preferably includes a heating element temperature measuring device (not shown) for measuring the temperature of the ceramic heating element composition 10.

In the dielectric heating heating apparatus 100 of the present invention configured as described above, the microwave transmitted through the waveguide 35 is irradiated to the heating container 40 and the ceramic heating element composition 10, and the microwave transmitted through the ceramic heating element composition 10 Not only the ceramic heating element composition 10 generates heat but also generates heat in the heating container 40. The generated heat is transferred to the heating oil 20.

Heat energy of the heat medium oil 20 can be exchanged with air or water to be used for a heater, a hot air fan, a water heater, and a heating device for an electric vehicle.

Next, the operation of the dielectric heating type heating apparatus 100 using the ceramic heating element composition 10 according to the present invention will be described.

When a power source is applied, a high voltage boosted from a transformer (not shown) is applied to the magnetron 30, and the magnetron 30 generates a microwave.

The microwaves generated from the magnetron 30 are transmitted to the heating container 40 and the ceramic heating element composition 10 through the waveguide 35.

Then, the heat generating container 40 and the ceramic heating element composition 10 are heated by the microwave, and the generated heat is transferred to the heat medium oil 20 to heat the heat medium oil 20.

The heating medium oil 20 heated by the heat generated in the heating container 40 and the ceramic heating element composition 10 is discharged through the oil feed pipe 46 and heat-exchanged with the heating medium of air or water to heat the heating medium, It can be used for heating devices and so on.

In addition, the present invention can control the heat generation temperature by controlling the magnetron 30.

Next, a dielectric heating type heating method using the ceramic heating element composition 10 and the dielectric heating type heating device 100 according to the present invention will be described.

The dielectric heating type heating method using the ceramic heating element composition (10) and the dielectric heating type heating device (100)

Packaging the ceramic heating body composition 10 with heat-resistant fibers (step 1);

(Step 2) of injecting the ceramic heating element composition 10 packaged with the heat resistant fiber into the heating container 40 of the dielectric heating heating device 100;

Filling the heating container 40 with the thermal oil 20 (step 3);

Applying power to the magnetron (step 4);

Irradiating the ceramic heating body composition 10 and the heating container 40 with microwave to generate heat (step 5); And

(Step 6) of heat-transferring the heat generated from the ceramic heating element composition 10 and the heat-generating container 40 to the heat medium oil 20; .

In the step 1, the ceramic heating element composition 10 is formed by mixing 10 to 50 weight parts of graphite with respect to 100 weight parts of any one selected from the group consisting of silicon carbide, silicon nitride and polysilicon And the like. 10 to 20 parts by weight of a binder may be further added to 100 parts by weight of the ceramic heating element composition, and the mixture may be solidified to be formed into a plate. The binder may be a silicone adhesive.

In the step 2, the ceramic heating element composition 10 packaged with the heat-resistant fibers may be placed in the lower part of the heat-generating container 40 and suspended in a granular form from top to bottom. The heat-generating vessel 40 is preferably made of borosilicate glass.

In the step 3, the heat medium oil 20 may be filled up to 75 to 85% of the capacity of the heat generating vessel 40. When the heat medium oil 20 is filled to less than 75% of the capacity of the heat generating vessel 40, the amount of heat transferred to the heat medium oil 20 is reduced. The heat medium oil 20 has a volume at a temperature of 300 ° C. 15% of the capacity of the heat-generating container 40 is filled up to 85% of the capacity of the heat-generating container 40. The heat medium oil 20 is not particularly limited, but paraffin oil or alkylbenzene oil can be used. The generation of hot spots can be reduced since the ceramic heating element composition 10 generates heat in the heating medium oil.

It is preferable to fill the thermal oil 20 so as to be 5 to 30 parts by weight of the ceramic heating element composition 10 with respect to 100 parts by weight of the thermal oil 20. When the ceramic heating element composition is filled in an amount of less than 5 parts by weight with respect to 100 parts by weight of the thermal oil, there is a problem in that the rate of temperature rise becomes slow. When the filling amount exceeds 30 parts by weight, hot spots may occur.

A step of covering and sealing the lid 72 of the external resonance chamber before the step 4 may be added.

In the step 5, not only the heat is generated in the ceramic heating body composition 10 but also the heat is generated in the heat generating vessel 40.

After step 6, the heat-transferred heat to the thermal oil 20 may be used for a heater, a hot air fan, a water heater, and a heating device for an electric vehicle by exchanging heat with air or water.

Next, a dielectric heating type heating apparatus 200 using a ceramic heating element composition according to another embodiment of the present invention will be described with reference to FIG.

The dielectric heating type heating apparatus 200 using the ceramic heating element composition according to another embodiment includes the heat exchanger 150 in the heating vessel 140 so that the ceramic heating element composition 110 can be heated by using microwaves generated by the magnetron. And transfers the heat energy generated by the heat to the heat medium oil 120 and heat-exchanges the heat transferred to the heat medium oil 120 with the heat transfer fluid passing through the space inside the heat exchanger 150.

The dielectric heating type heating apparatus 200 according to another embodiment of the present invention is configured to connect a heat transfer fluid, which is piped to an external device by an inlet pipe 102 and an outlet pipe 101, And then flows into the outlet pipe (101); A heat generating vessel 140 for receiving the heat exchanger 150 therein; A resonance chamber (170) for sealing the heat - generating container (140) while being accommodated therein; A heat insulating material (160) filled between the resonance chamber (170) and the heat generating container (140); A ceramic heating body composition 110 and a heating medium oil 120 filled in the heating vessel 140; A magnetron 130 for allowing the ceramic heating element composition 110 and the heat generating vessel 140 to be dielectric-heated by radiating a microwave to transmit heat to the heat transfer fluid passing through the internal space of the heat exchanger 150; And a waveguide 135 for irradiating the microwave to the inside of the heat generating container 140.

A magnetron controller is provided outside the resonance chamber 170 for controlling the wavelength and power of the microwaves and supplying electricity to the magnetron 130 to control the desired microwaves to be radiated. A control panel for controlling the operation of the magnetron controller according to the internal temperature of the resonance chamber 170 or the temperature of the heat transfer fluid and performing a control operation required for a heating device such as a temperature and an operating state of the display unit, In addition, a distributor can be installed at the end of the outflow pipe 101. The dielectric heating type heating device 200 thus formed can be accommodated in the frame and installed at a necessary place.

Here, the heat transfer fluid supplied to the inflow pipe 102 may be a liquid or gaseous fluid having fluidity, for example, water or air. The type of external equipment connected to the dielectric heating device according to the present invention .

The resonance chamber 170 is configured to close the internal space and allows the inlet pipe 102 and the outlet pipe 101 to pass through the pipe to the heat exchanger 150 installed in the internal space.

The resonance chamber 170 is provided with a heating medium oil discharge port 104 on which the valve 104 'is installed so that the heating medium oil 120 filled in the heating vessel 140 is discharged through the valve 104' I can do it. Since the heat medium oil 120 must be inserted into the heat generating vessel 140, the upper shell can be formed as a lid capable of opening and closing and the heat medium chamber lid 172 is opened and the heat medium oil 120 is introduced into the heat generating vessel 140 It is desirable to be able to insert it into the apparatus.

It is preferable that the heating container 140 uses borosilicate glass which generates heat when irradiated with a microwave. The upper part of the heating vessel 140 is closed by a heating vessel lid 142. The heating vessel lid 142 is provided with a fuel supply port 145 so that the heating oil 120 flows into the heating vessel 140). A heat-resistant packing 149 is provided on the joint portion between the heat-generating container 140 and the heat-generating container lid 142 so as to prevent the heat medium oil 120 from leaking. The ceramic heater element 110 and the heat medium oil 120 are placed in the internal space after the heat exchanger 150 is installed in the internal space of the heat generating container 140 and the ceramic heater element 110 And the heat medium oil 120 into the lower internal space, the air cock 143 for regulating the pressure of the air layer is provided on the upper side so as to intercept the inflow / outflow of air.

It is preferable that a heat insulating material 160 is filled between the resonance chamber 170 and the heat-generating container 140 to prevent the heat of the internal space from flowing out to the outside. Further, the resonance chamber 170 may be fabricated by a double-structured plate having an air layer formed between the two plates.

The heat exchanger 150 may be formed of a metal having a good thermal conductivity (for example, stainless steel or iron) to enhance the heat transfer efficiency of transferring the heat of the heat medium oil 120 to the heat transfer fluid.

Hereinafter, the constitution and effects of the present invention will be described in more detail through examples. These embodiments are only for illustrating the present invention, and the scope of the present invention is not limited by these embodiments.

[Experimental Example 1]

A quartz crystal was used as a heating vessel, and a microwave was irradiated in a state that the heating oil beaker and the ceramic heating body composition were not filled in the quartz crystal, and the heating characteristics are shown in Table 1. A microwave processor having a maximum rated high frequency output of 700 W equipped with a magnetron, a resonance chamber and a temperature measuring device was used.

Time (minutes) 2 4 6 8 10 Temperature (℃) 38 49 58 65 70

As shown in Table 1, the crystal heat-resistant beaker is crystalline, so that it is not heated by microwaves but passes through microwaves. However, when the temperature of the beakers is slightly increased, the heat of the coating applied to the walls of the resonant chambers is assumed to be heat conduction.

[Experimental Example 2]

A quarts crystal was used as a heating container, and only a heating medium was filled in the crystal heat-resistant beaker, and the ceramic heating element composition was irradiated with microwaves without being charged. The heating characteristics are shown in Table 2. Paraffin oil was used as the thermal oil, and the same apparatus as in Experimental Example 1 was used.

Time (minutes) 2 4 6 8 10 Temperature (℃) 39 43 50 55 57

As shown in Table 2, it can be seen that the thermal oil is crystalline and is not heated by microwaves, and a slight increase in temperature is assumed to be due to the thermal conductivity of the crystal heat-resistant beaker.

[Experimental Example 3]

Borosilicate glass was used as a heating vessel, microwave was irradiated in the borosilicate glass without filling the heating oil and the ceramic heating element composition, and the heating characteristics were shown in Table 3. The same apparatus as in Experimental Example 1 was used.

time
(minute) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Temperature
(° C) 40 71 98 124 154 169 183 194 201 205 208 211 212 213 213

In Table 3, it was confirmed that when borosilicate glass was used as a heat-generating vessel, the temperature was raised to 154 ° C in 10 minutes, the temperature was raised to 205 ° C in 20 minutes, and the critical temperature reached 213 ° C in 30 minutes.

Therefore, when borosilicate glass is used as the heat-generating vessel, heat is generated by the microwave.

[Experimental Example 4]

Borosilicate glass was used as a heat-generating vessel. The borosilicate glass was filled only with thermal oil, and the microwave was irradiated without filling the ceramic heating element composition. The heating characteristics are shown in Table 4. Paraffin oil was used as the thermal oil, and the same apparatus as in Experimental Example 1 was used.

time
(minute) 2 4 6 8 10 12 14 16 18 20 Temperature
(° C) 44 73 103 131 154 173 188 201 211 221

In Table 4, it can be seen that when the thermal oil is filled, the heating temperature is slightly higher than that of heating the heating vessel only. When the heating oil starts to be heated, the density and viscosity gradually decrease and the specific heat gradually increases. Is increased.

[Experimental Example 5]

Borosilicate glass was used as a heating vessel, 150 g of thermal oil was filled in the borosilicate glass, and 13.5 g of silicon carbide was filled in the furnace. The heating characteristics were shown in Table 5. Paraffin oil was used as the thermal oil, and the same apparatus as in Experimental Example 1 was used.

time
(minute) 2 4 6 8 10 12 14 16 18 20 22 24 Temperature
(° C) 37 69 101 130 152 171 188 202 215 228 242 255

As can be seen from Table 5, silicon carbide has excellent exothermicity as a whole, but the initial heating rate is slow.

Excessive use of silicon carbide to increase the initial heating rate can speed up the heat generation somewhat, but the possibility of hot spot is increased.

[Experimental Example 6]

Borosilicate glass was used as a heating vessel, 150 g of thermal oil was filled in the borosilicate glass, and 3 g of graphite was filled, and microwave irradiation was performed. The heating characteristics are shown in Table 6. Paraffin oil was used as the thermal oil, and the same apparatus as in Experimental Example 1 was used.

time
(minute) 2 4 6 8 10 12 14 16 18 20 22 Temperature
(° C) 44 84 120 150 175 195 211 223 235 246 257

From Table 6, it can be seen that the graphite can raise the temperature of the thermal oil to a high temperature at an early stage and can accelerate the heating rate quickly. When the graphite is mixed with the heat medium oil, some of them are immersed and some of them are distributed uniformly in the heat medium oil and float, and the heat medium oil is blackened. The suspended powders immediately heat up when the microwave is irradiated, and heat transfer to the heat medium oil enhances the heating effect.

10 parts by weight of graphite was mixed with 100 parts by weight of silicon carbide (SiC) to prepare a ceramic heating element composition. The silicon carbide was used in a size of 50 to 500 μm and the graphite was used in a size of 1 to 100 μm.

[Experimental Example 7]

Borosilicate glass was used as a heat-generating vessel, and 16.5 g of the ceramic heating element composition of Example 1 was packed in heat-resistant fibers through which microwaves were passed, placed in the lower part of the heat-generating vessel, 150 g of thermal oil was filled in the heat- And the heating characteristics are shown in Table 7. Paraffin oil was used as the thermal oil, and the same apparatus as in Experimental Example 1 was used.

time
(minute) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Temperature
(° C) 69 112 144 167 186 201 214 225 234 242 249 256 262 268 274

In Table 7, it can be seen that in the ceramic heating element composition of Example 1, silicon carbide generates heat as the main heating element, and graphite increases the initial heating effect and shortens the heating time. When the ceramic heating element composition of Example 1 is mixed into the heat medium oil, the entire amount of silicon carbide is immersed, and the graphite partly sinks like silicon carbide and partly floats in the heat medium oil. When the microwave is irradiated, the graphite microparticles floating in the heat medium oil, the silicon carbide and the graphite which are immersed, and the heating container are simultaneously heated. The heat is directly transferred to the heat oil, and the heat oil is uniformly heated in a short time.

20 parts by weight of graphite was mixed with 100 parts by weight of polysilicon (SiC) to prepare a ceramic heating element composition. Polysilicon was used in a size of 50 탆 to 2 mm, and graphite was used in a size of 1 to 100 탆.

[Experimental Example 8]

Borosilicate glass was used as a heating container. 9 g of the ceramic heating element composition of Example 2 was packed with heat-resistant fibers through which microwaves were passed and placed in the lower part of the heating container. 150 g of thermal oil was filled in the heating container, And the heating characteristics are shown in Table 8. Paraffin oil was used as the thermal oil, and the same apparatus as in Experimental Example 1 was used.

time
(minute) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 Temperature (℃) 38 71 109 134 166 187 203 214 222 229 236 244 252 260

From Table 8, it can be seen that the initial heat generation temperature of polysilicon is lower than that of silicon carbide. However, since polysilicon is high purity, there is an advantage that no hot spot is generated at all.

[Experimental Example 9]

In Experimental Example 7, the ceramic heat generating composition of Example 1 was irradiated with microwaves, and the heat transfer fluid, which was transferred with heat, was subjected to natural slow cooling in the open state, and the cooling characteristics of the heat transfer fluid were shown in Table 9.

time
(minute) 0 10 20 30 40 50 60 70 80 Temperature
(° C) 274 199 150 118 96 80 68 60 54

As shown in Table 9, it took 80 minutes for the thermal oil to cool from 274 ° C to 54 ° C. The amount of heat exchange can be controlled according to the heating temperature of the heating medium and the amount of the heating medium oil. Therefore, it can be seen that heat exchange with the water or the air such as a heater, a hot air heater, a water heater,

100: Dielectric heaters
10: Ceramic heating element composition 20: Heat medium oil
30: Magnetron 35: Waveguide
40: heating container 42: heating container cover
43: Air Cock 45:
46: Oil feed pipe 47: Circulating pipe
49: Packing
50: internal resonance chamber 52: internal resonance chamber chamber
59: packing 60: insulation
70: external resonance chamber 72: external resonance chamber cover
200: Dielectric heaters
101: outlet pipe 102: inlet pipe
104: Heat medium oil outlet 104 ': Valve
110: Ceramic heating element composition 120: Heat medium oil
130: Magnetron 135: Waveguide
140: heating container 142: foot container cover
143: Air Cock 145:
149: Packing
150: Heat exchanger 160: Insulation
170: External public room 172: External public room cover

Claims (6)

An external resonant chamber, an internal resonant chamber located inside the external resonant chamber, and a heat generating vessel located within the internal resonant chamber;
Wherein the heat generating container is filled with a ceramic heating element composition and a heat medium oil;
A heat insulating material is formed between the external resonance chamber and the internal resonance chamber to block heat outflow to the outside;
A waveguide as a propagation path for transmitting the microwave generated in the magnetron to the ceramic heating element composition;
Wherein the heating container and the ceramic heating element composition generate heat in response to microwaves transmitted through the waveguide to transfer heat to the heating oil,
Wherein the ceramic heating element composition comprises 10 to 50 parts by weight of graphite relative to 100 parts by weight of any one selected from the group consisting of silicon carbide, silicon nitride and polysilicon. Heating device using a ceramic heating element composition.
The method according to claim 1,
A heat exchanger is provided in the heat-
And the heat transferred to the heat medium oil is heat-exchanged with the heat transfer fluid passing through the space inside the heat exchanger.
The method according to claim 1,
Wherein the heating container is made of borosilicate glass.
Packaging the ceramic heating element composition with heat resistant fibers (step 1);
(Step 2) of putting the ceramic heating element composition packaged with the heat-resistant fiber into the heating container of the dielectric heating type heating device of claim 1;
Filling the heating container with thermal oil (step 3);
Applying power to the magnetron (step 4);
Irradiating the ceramic heating element composition and the heat generating container with microwave to generate heat (step 5); And
Heat-transferring the heat generated from the ceramic heating element composition and the heat-generating container to the heat medium oil (step 6);
, ≪ / RTI &
Wherein the ceramic heating element composition comprises 10 to 50 parts by weight of graphite relative to 100 parts by weight of any one selected from the group consisting of silicon carbide, silicon nitride and polysilicon. Ceramic heating element composition and dielectric heating type heating method using dielectric heating type heating device.
5. The method of claim 4, wherein in step 3,
Wherein the ceramic heating element composition is 5 to 30 parts by weight of the ceramic heating element composition based on 100 parts by weight of the thermal oil, and the dielectric heating type heating method using the dielectric heating type heating element.
5. The method of claim 4,
Wherein the thermal oil is selected from the group consisting of paraffin oil and alkylbenzene oil, and a dielectric heating method using the dielectric heating apparatus.

Images