KR20020056613A - Heat treatment apparatus of sheet type heated body and heat treatment method of the same - Google Patents

Abstract

PURPOSE: A heat treatment apparatus of a sheet type heated body and a heat treatment method of the same are provided which not only obtain high energy efficiency and heat treatment rate when heat treating the ceramic material by forming a ceramic material into a sheet type but also improve heat treatment properties of the heated body. CONSTITUTION: The heat treatment apparatus of a sheet type heated body(115) comprises one or more unit heat treatment systems(100) on which the heated body(115) is mounted, and on which a heating element(111) that is radiated by absorbing microwaves and heat treats the heated body(115) by conducting heat generated to the heated body(115) is put; a transfer part(120) for transferring the heated body(115) to inner and outer sides of the unit heat treatment systems(100); a microwave cutoff part(160) which is installed at the transfer part(120) to prevent leakage of microwaves; a cooling gas supply part(170) for controlling temperature inside the unit heat treatment systems(100) heated by the heating element(111) by infusing cooling gas into the unit heat treatment systems(100); a reactant treatment part(180) for treating reactants generated by heating of the heated body(115); and a main control part(190) for controlling the unit heat treatment systems(100), transfer part(120), cooling gas supply part(170) and reactant treatment part(180) by sensing temperature of the heated body(115), heating element(111) and the inside of the unit heat treatment systems(100).

Description

Heat treatment device for sheet-type heated object and heat treatment method {HEAT TREATMENT APPARATUS OF SHEET TYPE HEATED BODY AND HEAT TREATMENT METHOD OF THE SAME}

The present invention relates to a heat treatment apparatus for heat-treating a sheet-shaped object to be heated using microwaves, and a heat treatment method thereof.

When heat-treating the molded object to be heated, the air is heated by heat generated by electrical resistance and heat-heated to heat the object to be heated.

The conventional hot air heater has an air supply unit having an air input unit for inputting air required for hot air generation and an air filtering unit for filtering the air, and a fan cooling unit for preventing the fan and the fan from overheating to create hot air. And a hot air generator having a heater that generates heat by electric resistance. In addition, the hot-air heating apparatus further includes a heating body having a connecting device for guiding the generated hot air into the heating space, a heating furnace outer wall part for mechanically supporting the entire heating device, and a heat insulating part for insulating the generated hot air. In addition, the hot air heating apparatus includes a control unit having a sensor unit for measuring the temperature of the heat insulation unit, a control unit for temperature control, a cooling gas supply device for cooling the heat insulation unit after the heat treatment of the heating element, and a heat treatment of the heating element. It further comprises an exhaust device for exhausting the reactants generated when, and a conveying device for carrying in, carrying out and transporting the heated object.

The operation of the conventional hot air heating device configured as described above will be described.

First, the object to be heated is formed and placed in the carrying-on part, and the object to be heated is introduced into the hot air heater through the transfer part. Then, the air introduced from the air inlet is passed through the air filtering unit to remove foreign matters, and then is sent to the hot air generator, and blows heat generated by the heater to a fan to create hot air. The hot air is blown from the left to the right or from the right to the left or the back to the front of the heat insulating part of the hot air heating furnace to heat-treat the heated object to a desired temperature. The heat-treated to-be-heated body may be cooled by a cooling gas generated in the cooling apparatus, and when the cooling is completed, a molded body processed at a desired temperature may be obtained.

The conventional hot air heating device as described above has the following disadvantages.

First, in order to heat the object to be heated, since the hot air supplied with heat energy from the heat generated by the electrical resistor is heated, the heat efficiency of the heat treatment process is very low because it needs to be heated not only at room temperature but also at the surrounding process equipment. Second, dust generation is severe due to oxidation of the heating element and supply of hot air, resulting in product defects of the heating element. Third, in the case of rapid cooling after the heat treatment of the heating element, tensile stress is generated and cracks are generated in the product. Fourth, in the case of the hot air method, the larger the heat treatment area of the heated object is, the lower the temperature uniformity during heat treatment causes various problems such as staining, thickness unevenness, and poor internal structure during the drying or plastic processing of the product. Fifth, when the heat treatment area of the heated object is increased or the thickness of the heated object is increased or the throughput of the heated object is increased, the length of the heat treatment furnace must be long, so that the investment cost increases and productivity is lowered.

The present invention has been made to solve the above disadvantages, an object of the present invention is to improve the heat treatment properties of the sheet-shaped heating body while at the same time to obtain a high energy efficiency and fast heat treatment rate when forming the ceramics in the form of a sheet heat treatment The present invention provides a sheet-type heated object heat treatment apparatus and a heat treatment method thereof.

1 is a view showing the configuration of a heat treatment apparatus according to an embodiment of the present invention.

Figure 2a and Figure 2b is a view showing the internal structure when the heating object is dried by a conventional hot air heater and the heat treatment apparatus according to the present embodiment.

Figure 3a and Figure 3b is a view showing the internal structure when the heated object is fired by the conventional hot air heater and the heat treatment apparatus according to this embodiment.

* Description of the symbols for the main parts of the drawings *

100: unit heat treatment device 111: heating element

115: heating element 120: transfer unit

131: microwave upper side generating unit 135: microwave lower side generating unit

140: Cavity 150: Applicator

160: microwave blocking unit 170: cooling gas supply unit

180: reactant processing unit 190: main control unit

In the heat treatment apparatus for heating a sheet-shaped to-be-heated body according to the present invention for achieving the above object,

At least one unit heat treatment device in which the heating element is mounted and absorbs microwaves to generate heat and conducts heat generated to the heating element to heat the heating element; A transfer unit which transfers the heated object to the inside and the outside of the unit heat treatment apparatus; A microwave cutoff part installed in the transfer part to prevent the microwave from leaking; Cooling gas supply unit for controlling the temperature inside the unit heat treatment apparatus heated by the heating element by injecting a cooling gas into the unit heat treatment apparatus; A reactant processing unit configured to process reactants generated by heating of the heated object; And a main control unit which senses a temperature inside the heated object, the heating element, and the unit heat treatment device to control the unit heat treatment device, the transfer unit, the cooling gas supply unit, and the reactant treatment unit.

In the heat treatment method for heating a sheet-like to-be-heated body according to the present invention for achieving the above object,

Mounting the heated object on a heating element that generates heat by microwaves and transferring the inner and outer sides of a unit heat treatment apparatus; Generating a microwave by controlling the microwave generator installed in the unit heat treatment apparatus; Blocking microwaves leaking from the unit heat treatment apparatus when the heating element is transferred to the unit heat treatment apparatus; Primary insulating heat generated from the heating element; Preventing heat of the microwave at the same time as the second heat insulating heat generated by the heating element; Conducting heat generated by the heating element to the heated object; Supplying a cooling gas for controlling the primary insulated temperature; Treating reactants generated by heating of the heated object; Sensing the temperature of the heated object, the heating element, and the unit heat treatment apparatus to control the unit heat treatment apparatus, the transfer of the heated object, the supply of the cooling gas, and the treatment of the reactant.

Hereinafter, with reference to the accompanying drawings will be described in detail a sheet-like heated object heat treatment apparatus and a heat treatment method according to an embodiment of the present invention.

1 is a view showing the configuration of a heat treatment apparatus according to an embodiment of the present invention.

As illustrated, the unit heat treatment apparatus 100 in which the sheet-shaped heating element 111 and the sheet-shaped object to be heated 115 are provided is provided. Inside the unit heat treatment apparatus 100, more specifically, the microwave upper generating unit 131 and the microwave lower generating unit 135 for generating a microwave from below and above the heating body 115, The microwaves are absorbed by the upper and lower generators 131 and 135 to generate heat from the heating element 111. In addition, a cavity 140 is installed inside the unit heat treatment apparatus 100 to primarily insulate heat generated from the heat generating element 111, and the heat generating element 111 and the heated object 115 are provided inside the cavity 140. Is positioned to generate heat and heat. In addition, the applicator 150 is installed inside the unit heat treatment apparatus 100 in a form surrounding the cavity 140. The applicator 150 has a heat insulating portion 151 and an outer wall portion 155 supporting the cavity 140 and preventing leakage of secondary heat and microwaves.

In and out of the unit heat treatment apparatus 100, an import unit 121, a unit transfer unit 125, and an export unit for carrying in, transporting, and transporting the heating element 111 or the heated object 115 to the unit heat treatment apparatus 100. The transfer part 120 including the part 129 is provided. At this time, the microwave blocking unit 160 is installed in the transfer unit 120 in order to prevent the microwaves in the unit heat treatment apparatus 100 from leaking through the import unit 121 and the export unit 129. More specifically, the microwave blocking unit 160 is provided in the import unit 121 and the export unit 129, respectively.

In addition, the outside of the unit heat treatment apparatus 100 is provided with a cooling gas supply unit 170 for controlling the temperature of the cavity 140 warmed a predetermined temperature, supplying the cooling gas to the space of the cavity 140. In addition, a reactant treatment unit 180 for flowing out and treating a reactant generated while the heated object 115 is heated from the cavity 140 is provided outside the unit heat treatment apparatus 100. In addition, the sensor unit 191 which detects the temperature of the heating element 115, the temperature of the heating element 111, and the temperature of the cavity 140, and controls the operations of the cooling gas supply unit 170 and the reactant processing unit 180. The main controller 190 having a sub controller 195 is provided.

The heat treatment apparatus according to the present embodiment may be configured in the form of a batch furnace and a continuous furnace.

In the case of the intermittent path, one unit heat treatment apparatus 100 including the microwave upper and lower generators 131 and 135, the applicator 150, the cavity 140, and the heating element 111, and the cooling gas supply unit ( 170, the reactant processing unit 180, the main control unit 190, the microwave blocking unit 160, and the transfer unit 120.

In the case of a continuous furnace, at least two unit heat treatment apparatuses 100 are continuously installed, and the cooling gas supply unit 170, the reactant processing unit 180, the control unit 190, the microwave blocking unit 160, It is made of a transfer unit 120. At this time, the transfer unit 120 is a carrying-in unit 121 for carrying in the heating element 111 and the heating element 115 to the unit heat treatment apparatus 100, and the heating element 111 and the heated object in the unit heat treatment apparatus 100. At least one unit transfer unit 125 for transferring the sieve 115, and the carrying out unit 129 for carrying out the heating element 111 and the heating target body 115 from the unit heat treatment apparatus (100). In addition, as a means for conveying, there are a mesh belt, a roller, and a shuttle-type device, and a combination of one or more of them is configured.

The operation of the heat treatment apparatus according to the present embodiment and the heat treatment method thereof will be described.

The sheet-like to-be-heated body 115 used in the present embodiment is heat-treated by forming a sheet-like ceramic molded body on the sheet-like ceramic molded body itself, which is about to be heat-treated, or a sheet-like substrate made of any one of inorganic, organic and metal materials. The composite to be called is the sheet-like heated body 115.

The to-be-heated body 115 is generally expressed as a paste or slurry, and is a mixture of solids made of ceramic or ceramic-glass or glass and a vehicle for imparting bonding strength of the molded body. (Hereinafter referred to as "consumables")

The ceramics are generally embodied in a sheet-like single or pattern form by a method such as doctor blading, screen printing, casting, dipping, pressing, table coating, and the like. It also includes the case of forming new sheet-like ceramics having different functions on the ceramic layer or forming sheet-shaped ceramic layers having different functions at once. Thereafter, the heating element 115 is mounted on the heating element 111 when the heating element 111 generates heat by generating the microwave and generating the microwaves by heat treatment such as drying or firing. Indirect heating is used to conduct heat to the heated object 115 to heat-treat the heated object 115.

Here, the principle of heat generation by microwave is as follows.

When a dipole is present inside the heating element, if a strong electric field is given therein, the dipole is aligned in the electric field direction, and when the electric field is caught in the reverse direction, the dipole is also arranged in the opposite direction. In this way, dipole rotation or vibration occurs in the molecule, and heat is generated by the internal friction. At this time, the power loss that is converted into heat among the heating elements is given as follows.

Where P is the power loss, f is the frequency of the microwave (Hz), υ is the magnitude of the microwave field (V / m), ε is the relative dielectric constant of the material, and tanδ is the dielectric loss angle.

The power loss is converted into heat generated per unit volume per hour as follows.

Therefore, the amount of heat Q given in the above formula is conducted to heat the sheet-like object to be heated 115.

Based on the above principle, the operation through the heat treatment apparatus according to the present embodiment is as follows.

First, the ceramic product is formed into a sheet-like heated object 115 by the molding method described above and mounted on the heating element 111. In this case, the heating element is made by compression molding into a sheet of a material having a high loss tangent value. Thereafter, the heating element 115 and the heating element 111 are positioned in the carrying-in unit 121, and are introduced into the unit heat treatment apparatus 100 through the unit transfer unit 125. Then, the microwaves are irradiated to the heating element 111 by the microwave upper and lower generators 131 and 135. At this time, the magnetrons used in the microwave upper and lower generators 131 and 135 are 915MHZ or 2.45GHZ, which are commonly used, and are arranged in the microwave upper and lower generators 131 and 135.

Here, both of the microwave upper and lower generators 131 and 135 may be used, or only the microwave upper generator 131 may be used, or the micrometer may be used in consideration of variables such as substrate material, ceramic characteristics, and heating temperature uniformity. Only the wave lower generation unit 135 may be used.

When microwave irradiation is made, the heating element 111 generates heat, and the heat is transmitted to the heating element 115. At this time, a space for preventing heat loss and uniform heating is required, which is solved by the cavity 140. The cavity 140 mechanically supports the entire cavity 140 and is well insulated while simultaneously passing the microwave well, that is, preventing loss and uniformity of heat generated from the heating element 111 using materials having low loss tangent values. Heating can be achieved.

In addition, when the microwave 140 is irradiated with the cavity 140, the applicator 150 supports the cavity 140 and insulates the heat generated from the heat generating element 111 secondly, and the micro The outer wall portion 155 is formed of a metal material to prevent the wave from leaking to the outside of the unit heat treatment apparatus 100.

When the heating element 115 is heat treated by the microwave, it is generally heat treated along the temperature profile (Profile) in order to avoid product defects of the heating element 115. That is, it consists of a temperature increase section having a specific temperature increase rate per hour, the maximum temperature holding section having a maximum temperature holding time according to the heat treatment purpose, such as drying or firing, and a cooling section having a specific cooling rate per hour.

Here, the continuous furnace form according to the present embodiment may implement the temperature profile by connecting two or more unit heat treatment apparatuses 100 in parallel.

For example, when three or more are connected in series, a continuous furnace is composed of one unit heat treatment apparatus 100 for heating, one unit heat treatment apparatus 100 for maintaining the maximum temperature, and one unit heat treatment apparatus 100 for cooling. can do.

In the case where two unit heat treatment apparatuses 100 are continuously provided, if one unit heat treatment apparatus of the continuous unit heat treatment apparatus maintains an elevated temperature and a maximum temperature, the other unit heat treatment apparatus has a cooling zone. do. Alternatively, if one unit heat treatment apparatus of the continuous unit heat treatment apparatus is a temperature raising zone, the other unit heat treatment apparatus maintains a maximum temperature and becomes a cooling zone. That is, one unit heat treatment apparatus (100) and the cooling unit heat treatment apparatus (100) for the role of maintaining the temperature and the maximum temperature can be configured as a continuous furnace, and the unit heat treatment apparatus for temperature increase for precise control of the temperature increase ( At least two 100 units may be used, and a continuous furnace may be configured by one unit heat treatment apparatus 100 for maintaining the maximum temperature and one unit heat treatment apparatus 100 for cooling. In addition, in addition to the configuration method mentioned above, various parallel connections corresponding to three sections are possible according to ceramic heat treatment characteristics.

In addition, the intermittent path form continuously controls the temperature, maximum temperature, and cooling intervals by controlling the microwave generation degree and the cooling gas supply degree by controlling the temperature in the cavity 140 space using one unit heat treatment apparatus 100. It is possible to implement temperature profiles to process.

As described above, when the object to be heated 115 is treated in the unit heat treatment apparatus 100, air, nitrogen gas, hydrogen gas, and oxygen are responded to the temperature control of the temperature profile and the appropriate heat treatment reaction characteristics of the object to be heated 115. Cooling gas such as gas is supplied through the cooling gas supply unit 170. In addition, when the object to be heated 115 is heat-treated, reaction products such as waste gas, oxides, carbides, etc. are generated, which reactant processing unit 180 extracts the reaction products from the cavity 140 and processes the reactants.

In addition, since the import unit 121 and the export unit 129 are opened to the outside of the unit heat treatment apparatus 100, microwaves generated from the microwave upper and lower generators 131 and 135 leak to the outside of the unit heat treatment apparatus 100. It may be, which is not leaked by the microwave blocking unit 160. That is, a metal shutter is installed at the connection portion between the carry-in unit 121, the unit heat treatment apparatus 100, and the carry-out unit 129 to open the shutter only when the heated object 115 is brought in or taken out. A choke is provided in the 121 and the carrying out portion 129 so that the phase difference between the reflected wave of the microwave and the wave outward is λ / 2 so as to cancel the microwave or the loss in the microwave shield 160. The microwave leakage is prevented by installing a microwave absorber with a large tangent.

In addition, the main control unit 190 is required to adjust the degree of generation and uniformity of the microwave, the degree of transfer of the heating object 115, the temperature profile for heat treatment, the degree of supply of cooling gas, and the degree of treatment of the reactants. . That is, the sensor unit 191 installed in the unit heat treatment apparatus 100 measures the temperature of the heating element 115 and the temperature at the time of absorbing the microwaves and generating heat and the temperature in the cavity 140 to control the sub-control unit 191. ), And the sub-control unit 191 calculates the information to control the control factors.

The heated object 115 heat-treated and cooled according to the heat treatment purpose of the heated object 115 is carried out to the carrying out portion 129 via the unit transfer part 125.

Hereinafter, specific experimental examples according to the present embodiment will be described.

The ceramics are composed of 80% PbO-B 2 O 3 -SiO 2 -based glass powder and 20% vehicle, and the ceramics are printed on a glass substrate with a screen printer. That is, the ceramic material is placed on an opening plate with 250 mesh, scraped and squeezed to form a sheet-like ceramic material printed on the substrate.

After that, the ceramic product is introduced into the conventional hot air heater and the heat treatment apparatus according to the present embodiment, and the temperature profile is set as shown in Table 1.

Temperature profile settings Temperature rise rate (℃ / min) Bike combustion temperature / holding time (℃ / min) Temperature / holding time (℃ / min) Cooling rate (℃ / min) Temperature profile total time (minutes) Hot air heating furnace 5 350/60 550/60 1.9 1,185 Heat treatment device according to the present invention 20 350/10 550/30 10 129

As described above, the total time required for the temperature profile is about 1/10 of that of the hot air heating device, whereas the hot air is heat-treated from the surface of the ceramic to the inside. In addition to the volume heating and selective heating, the heating element 111 is directly heated under the heating element 115, so that the heating time is good and the heating time can be shortened. In addition, also in cooling, the hot air heater must cool the heating volume as much as the space in the hot air heater, and in order to prevent defects of the heated object 115 due to quenching, the cooling speed cannot be increased.

However, in the heat treatment apparatus according to the present embodiment, since the space of the cavity 140 is not very small as compared with the hot air firing furnace, it is possible to remove the tensile stress generated during the quenching, such as bending, cracking, etc., generated in the heated object 115. Can be quenched without product defects.

As described above, the dry state and the calcined state after heat treatment by the conventional apparatus and the apparatus according to the present embodiment are illustrated in FIGS. 2A to 3B.

2A and 2B are views illustrating an internal structure when a heated object is dried by a conventional hot air heater and a heat treatment apparatus according to the present embodiment, and FIGS. 3A and 3B illustrate a conventional hot air heater and the present embodiment Figure shows the internal structure when the heating element is fired by the heat treatment apparatus according to the present invention.

As shown in the drawing, the scanning electron microscope photograph was taken to observe the internal structure of the heated object 115. As a result, in the drying and firing state by the conventional apparatus and the drying and firing state by the apparatus according to the present embodiment. The result is that there is no difference in quality characteristics.

As described above, the sheet-shaped to-be-heated body heat treatment apparatus and the heat treatment method according to the present invention is not a method of applying heat from the outside, the energy efficiency is very high, and a fast heat treatment rate can be obtained.

In addition, since the heating power and heating and cooling temperature control is easy and the energy efficiency is high, the size of the equipment can be significantly reduced compared to the existing hot air heater.

In addition, there is no dust generated by the oxidation of the heating element and the supply of hot air, so there is no product defect of the heating element due to foreign matter.

In addition, since temperature uniformity is good and induction of product defect factors such as tensile stress is suppressed, it is easy to enlarge the heat treatment area of the heating element and to thicken the film, and to greatly improve the required physical properties of the product.

In the above, the present invention has been described in accordance with one embodiment of the present invention, but those skilled in the art to which the present invention pertains have been changed and modified without departing from the spirit of the present invention. Of course.

Claims (7)

In the heat treatment apparatus for heating a sheet-like object to be heated, At least one unit heat treatment device in which the heating element is mounted and absorbs microwaves to generate heat and conducts heat generated to the heating element to heat the heating element; A transfer unit which transfers the heated object to the inside and the outside of the unit heat treatment apparatus; A microwave cutoff part installed in the transfer part to prevent the microwave from leaking; Cooling gas supply unit for controlling the temperature inside the unit heat treatment apparatus heated by the heating element by injecting a cooling gas into the unit heat treatment apparatus; A reactant processing unit configured to process reactants generated by heating of the heated object; And, And a main controller configured to sense a temperature inside the heated object, the heating element, and the unit heat treatment device to control the unit heat treatment device, the transfer unit, the cooling gas supply unit, and the reactant treatment unit. Heat treatment device. The method of claim 1, The unit heat treatment apparatus, A microwave generator configured to generate microwaves in the upper and lower sides of the unit heat treatment apparatus; A cavity provided inside the unit heat treatment apparatus and disposed with the heat generator, and configured to primarily insulate heat generated from the heat generator; A sheet-shaped heat-treatment apparatus for heating a sheet, characterized in that it has an applicator installed inside the unit heat treatment apparatus to surround the cavity and supporting the cavity to prevent secondary leakage and at the same time prevent leakage of the microwave. The method of claim 2, Only one unit heat treatment device is provided, The inside of the unit heat treatment apparatus is a sheet-type heated object heat treatment apparatus, characterized in that it has a temperature rising section to be heated by a predetermined time unit, the maximum temperature holding section to maintain the maximum temperature and the cooling section to be cooled. The method of claim 2, The unit heat treatment apparatus is provided in two, If one unit heat treatment apparatus of the continuous unit heat treatment apparatus maintains the elevated temperature and the maximum temperature, the other unit heat treatment apparatus becomes a cooling zone, And if one unit heat treatment apparatus of the continuous unit heat treatment apparatus is an elevated temperature zone, the other unit heat treatment apparatus is a maximum temperature maintaining and cooling zone. The method of claim 2, The unit heat treatment apparatus is connected to three or more continuously, Inside the continuous unit heat treatment apparatus, a temperature raising part for heating the heated object, a maximum temperature holding part for maintaining the heated object at a maximum temperature, and a cooling part for cooling the heated object are divided at predetermined intervals. Sheet-shaped heating element heat treatment apparatus, characterized in that. The method of claim 1, The transfer unit includes a carrying-in unit for transferring the heating element and the heated object to the unit heat treatment device, a unit transferring unit for transferring the heating element and the heated object into the cavity, and the heating element and the heated object. And a carrying-out unit for carrying out to the outside of the unit heat treatment apparatus. In the heat treatment method of heating the sheet-shaped object to be heated, Mounting the heated object on a heating element that generates heat by microwaves and transferring the inner and outer sides of a unit heat treatment apparatus; Generating a microwave by controlling the microwave generator installed in the unit heat treatment apparatus; Blocking microwaves leaking from the unit heat treatment apparatus when the heating element is transferred to the unit heat treatment apparatus; Primary insulating heat generated from the heating element; Preventing heat from microwaves while simultaneously insulating heat generated by the heating element; Conducting heat generated by the heating element to the heated object; Supplying a cooling gas for controlling the primary insulated temperature; Treating reactants generated by heating of the heated object; Sensing the temperature of the heating element, the heating element, and the unit heat treatment device to control the unit heat treatment device, the transfer of the heating element, the supply of the cooling gas, and the treatment of the reactant. Sheet type heating element heat treatment device.