KR20100131129A - Sintering furnace or heat treatment furnace enhanced by the module of uniformizing heat flux and gas flow at low temperature zone and accelerating cooldown speed - Google Patents

Abstract

PURPOSE: A sintering furnace or heat treatment furnace enhanced by a module for uniformizing heat flux in a low temperature zone and accelerating cooling speed is provided to maintain uniform temperature of gases circulated through a heating chamber by employing a separate heater in a circulation path of a low temperature heating/cooling circulating unit. CONSTITUTION: A sintering furnace or heat treatment furnace comprises a high temperature heating unit(20), a low temperature heating/cooling/circulating unit(30), and a heat flux circulating drive unit(40). The high temperature heating unit is coupled with an insulating member(21) and a heat-proof bottom plate(22) on which an object(10) is placed, and comprises a heating chamber(25). The low temperature heating/cooling/circulating unit is formed with an internal circulation space(32) in which gases are circulated to uniformize heat flux in low temperature heating and improve cooling speed in cooling.

Description

Sintering furnace or heat treatment furnace enhanced by the module of uniformizing heat flux and gas flow at low temperature zone and accelerating cooldown speed}

The present invention relates to a high-quality sintering furnace or heat treatment furnace with a uniform heat flow and cooling acceleration module attached to a low temperature operating section. In particular, the temperature distribution and the flow of the atmosphere gas are uniform throughout the entire temperature range from low temperature to high temperature, The present invention relates to a sintering furnace or a heat treatment furnace for forcibly circulating a cooling gas to increase a cooling rate.

In general, the injection molding technology of the inorganic material powder has been actively used in recent years because it is possible to make a molded article of a complicated shape that cannot be obtained by conventional compression molding.

For injection molding, an organic binder or the like is added to the inorganic material powder in order to give bonding and fluidity to inorganic materials such as metal or ceramic powder, and the inorganic material to which the organic binder is added is molded into a desired shape, followed by heat sintering. Through the production of the final product through the bar, it is essential to remove the organic binder at a low temperature before sintering, this organic binder removal process is called a degreasing process is a fairly difficult process of the entire heating firing process.

An electric furnace-type high-temperature sintering furnace is used as an equipment for finally heating and firing a product molded through the injection molding technology of the inorganic material powder as described above.

In the high temperature sintering furnace, the object to be heated is loaded into the product loading space and the object to be heated is heated by a heater that is far away from each other. The so-called convective heat transfer is the main heat transfer action, heating the furnace chamber itself and the workpiece. Above 600 ° C, the heater's heat does not pass through the medium such as gas, but directly in the form of electromagnetic waves. The so-called heat transfer action called radiant heat transfer proceeds together to be heated.

In this way, the convective and radiant heat go together, but as the temperature increases, the volume of the gas expands and the density of the gas inside the chamber decreases, so that the specific gravity of the convective heat decreases gradually. Is reduced to less than a quarter, and the heating proceeds almost exclusively by radiative heat transfer.

In the low temperature operating section of 900 ° C or less, especially 600 ° C or less, which is almost no radiant heat, heat is concentrated on the upper side by natural convection while the flow is stagnant due to the loading of the workpiece. There is no convection and local heating is delayed, resulting in very uneven distribution of heat and flow in the furnace chamber.

To solve this problem, the gas inside the furnace chamber is forced to circulate so that heat and flow are uniformly distributed throughout the furnace chamber.

As a result, forcible convection can be generated by installing a metal fan and a flow box inside the furnace chamber in an electric furnace device of 1200 ° C or lower, but in an electric furnace device of 1200 ° C or higher, it can stably withstand temperatures of 1200 ° C or higher in the air. Since there is no material available, the fan and flow box cannot be installed inside the furnace chamber.

As a result, the current furnace apparatus having a temperature of 1200 ° C or higher can realize a uniform temperature distribution mainly by radiative heat transfer at a high temperature, but since there is no device capable of generating forced convection inside the furnace chamber, especially in a low temperature region, especially 600 ° C. Hereinafter, there is a limit that the temperature and flow distribution will be very uneven.

By the way, in most heat firing treatments, the plasticity can be ensured only by the temperature uniformity in the high temperature holding section, so there is no problem of heat flow non-uniformity in the low temperature section. In the sintering of the molded body of the ceramic or metal powder, the defect rate occurring in the final product is very high by entering the sintering process in the state where degreasing does not proceed properly due to heat flow unevenness in the low temperature region. there is a problem.

In other words, in the production of high-priced products such as ceramic powder-formed sintered products, especially ITO (Indium Tin Oxide) Target, it has a fatal effect on quality and cost, and it is urgent to develop alternative proposals and countermeasures to compensate for this. .

On the other hand, even in the heat treatment of metal, when heat-treating a metal product of a material or shape that is sensitive to the slight difference in temperature, if the temperature distribution is not uniform in the preheating step in the low temperature section, deformation such as fine warpage occurs. In the high temperature process, the deformation state is fixed as it is, or worse, the product defect is increased.

Therefore, the present invention has been made in view of the problems of the prior art as described above, when heat is heated at a temperature lower than 900 ° C., the heat is concentrated by convective heat, and in the middle or the bottom, the flow of gas due to the loading of the heating body is In this case, connect the low temperature heating / cooling circulation part and the heat flow circulation driving part combined with one assembly module to the heating chamber of the high temperature sintering furnace (or metal heat treatment furnace). The purpose is to provide a high quality sintering furnace, heat treatment furnace, or heat treatment furnace attached to a low-temperature operating section that provides uniform heat and flow in a non-uniform state by forcibly agitating the gas inside the heating chamber. have.

In addition, another object of the present invention is to uniformly heat and flow surrounding the entire heating body by circulating and stirring the internal gas in a low temperature region of 900 ℃ or less, thereby uniform degreasing (or pre-heat treatment) throughout the heating body. To make it work.

In addition, another object of the present invention is to install and operate a separate heater in the circulation passage of the low-temperature heating / cooling circulation section so that the temperature of the heated gas in the process of forcibly circulating the internal gas of the high-temperature furnace heating chamber By maintaining the same temperature as the inside of the heating chamber to ensure that the gas circulating in and out of the heating chamber at a high temperature to maintain a constant temperature.

In addition, another object of the present invention is a cooling gas cooled by the communication between the space of the low temperature heating / cooling circulation section and the external space in which the cold gas is heated during the degreasing and sintering process or the metal heat treatment of the heating target object It is to circulate through the furnace heating chamber to increase the cooling rate.

In order to achieve the above object, the present invention is a sintering furnace (or metal heat treatment furnace) for producing a sintered body part by degreasing / sintering / cooling while heating a heated body which is a ceramic or metal powder molded body from low temperature to high temperature, A tube into which a high temperature heating heater is inserted into an inside of a high temperature heating space in which heat insulating members are joined to each other and a heat resistant bottom plate on which a heated object, which is a ceramic or metal powder molded body (or a metal product), is mounted, is connected to each other. Forming a high temperature heating unit consisting of a high temperature electric furnace of the form, extending the heat insulating material in the form of a tube so that the low-temperature operating heater is installed therein, and is provided with a heat insulating shutter for opening and closing at both ends of the heat insulating material A low temperature heating / cooling circulation part is formed so that both ends of the heat insulating material are attached to the side surface of the high temperature heating part. Heat flow in which the high temperature heating space and the circulation space are integrally or detachably connected to penetrate the heat insulating member positioned to be opened or closed, and a circulation fan rotated by the driving force of the driving motor is inserted into the circulation space of the low temperature heating / cooling circulation portion. Low temperature operation by forming a circulation drive unit, circulating the gas in the high temperature heating space of the high temperature heating section and the circulation space of the low temperature heating / cooling circulation section so that the heat flow is uniform during low temperature heating and the cooling rate is reduced during cooling Provides high quality sintering furnace or heat treatment furnace with section heat flow uniformity and cooling acceleration module.

As described above, in the present invention, when the low temperature heating temperature of 900 ° C. or lower is concentrated, heat is concentrated in the upper portion and the flow of gas is generated due to the loading of the heated object. It is effective to make it uniformly distributed so that degreasing (or preheating) occurs uniformly.

In addition, by circulating heat and flow in a low temperature region of 900 ° C or less, uniform degreasing (or preliminary heat treatment) is performed in the entire heated object, thereby increasing the completeness of the product during sintering (or final heat treatment). .

In addition, the degreasing (or pre-heating) process may be performed by operating a separate heater formed in the low temperature heating / cooling circulation unit so that the temperature of the heated gas is not lowered when the internal gas of the high temperature heating unit is forcedly circulated. There is an effect that the efficiency or quality is not degraded due to the change in temperature.

In addition, during cooling of the heated object undergoing degreasing and sintering or metal heat treatment, the space inside the low temperature heating / cooling circulation portion communicates with the external space where cold gas exists to circulate the cooled cooling gas through the high temperature heating portion. This speeds up the effect.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

As shown in Figure 1, the high-temperature sintering furnace or heat treatment unit attached to the low-temperature operating section heat flow homogenization and cooling acceleration module of the present invention the high-temperature sintering furnace or heat treatment unit attached to the low temperature operating section heat flow homogenization and cooling acceleration module ceramic or metal The present invention relates to a sintering furnace or a heat treatment furnace (100) for producing a sintered compact part by degreasing / sintering / cooling a heated object (10), which is a powder compact, from low temperature to high temperature.

First, the sintering furnace or heat treatment furnace 100 is a high temperature heating unit 20 for heating the heating element 10 to a high temperature of 1200 ℃ or more at room temperature, and the heating element 10 in the high temperature heating unit 20. Low temperature heating / cooling circulation part 30, which serves as a passage for circulating gas in the high temperature heating part 20 during heating or cooling after sintering at a low temperature range of 600 to 900 ° C, and low temperature for circulating a heating gas or a cooling gas It consists of a heat flow circulation drive unit 40 installed in the heating / cooling circulation section (30).

The high temperature heating unit 20 is formed by the heat-resistant bottom plate 22 to which the heat-insulating member 21 is mutually coupled to form an upper side and a four-sided side, and a heating body 10, which is a ceramic or metal powder, is placed at the bottom thereof. It consists of a high temperature furnace heating chamber 25 in the form of a cylinder into which the high temperature heating heater 24 is inserted into the high temperature heating space 23.

Here, the heat insulating member 21 of the high temperature furnace heating chamber 25 is able to withstand high temperatures of more than 1200 ℃ It is composed of a heat-resistant material interconnected to surround the four sides of the roof and the upper, left, right, front and rear sides After the heat-resistant bottom plate 22 is to be coupled to the bottom.

In addition, at least one temperature measuring sensor 21a is inserted into the high temperature heating space 23 through the heat insulating member 21 forming a roof on the upper portion of the high temperature furnace heating chamber 25.

The low temperature heating / cooling circulation part 30 extends the heat insulator 33 in the form of a tube so that the low temperature operating heater 31 is provided with a circulation space 32 installed therein, and both ends of the heat insulator 33 are formed. It is formed by having an insulating shutter 34 that is opened and closed by pneumatic operation.

That is, the low temperature heating / cooling circulation part 30 circulates with the high temperature heating space 23 by passing through the heat insulating member 21 in which both ends of the heat insulating material 33 face the side of the high temperature heating part 20. The space 32 is formed to be integrally or detachably connected to open and close.

At this time, the low temperature heating / cooling circulation part 30 is formed by extending both ends of the heat insulating material 33 in various forms.

Here, the low temperature operation heater 31 of the low temperature heating / cooling circulation unit 30 is composed of a plurality, the low temperature operation heater 31 is 600 ~ to be heated to 10 in the high temperature heating unit (20). When heated to a low temperature of 900 ℃ heat generated in the high temperature furnace heating chamber 25 is assisted to generate heat so that the temperature does not lower during circulation so that the circulation space 32 has the same temperature as the high temperature heating space 23 It is.

In addition, the temperature measuring sensor 31a for measuring the temperature of the low temperature operation heater 31 is installed to penetrate the heat insulating material 33 and to be exposed into the circulation space 32.

In addition, the upper portion of the low temperature heating / cooling circulation part 30 further includes one or more cooling dampers 35 penetrating the heat insulating material 33 to open and close the circulation space 32 and the external space. .

That is, the cooling damper 35 is configured to cool the low temperature heating / cooling circulation unit 30 by introducing an external cooling gas while discharging the heated gas existing in the circulation space 32.

The heat flow circulation driving unit 40 is installed in the circulation space 32 of the low temperature heating / cooling circulation unit 30 is a circulation fan 42 rotated by the driving force of the drive motor 41.

Here, the drive motor 41 of the heat flow circulation drive unit 40 is configured to control the rotation speed by the inverter 43, it is configured to control the circulation speed.

In addition, the driving motor 41 and the inverter 43 are coupled to the outside of the heat insulating material 33 of the low temperature heating / cooling circulation part 30 and are not affected by heat, and the circulation fan 42 penetrates the heat insulating material 33. Is coupled to the motor shaft (not shown) is located in the circulation space (32).

That is, the low temperature heating / cooling circulation unit 30 circulates the gas in the high temperature heating space 23 of the high temperature heating unit 20 and the circulation space 32 of the low temperature heating / cooling circulation unit 30 to heat the low temperature. The heat flow is uniform and the cooling rate is configured to shorten during cooling.

Hereinafter, the operation and operation of the present invention will be described.

As shown in FIG. 2, the sintering furnace or the heat treatment furnace 100 is a heated body that is a ceramic powder or a metal powder molded body (or a metal product) on the heat-resistant bottom plate 22 forming the high temperature heating unit 20 ( 10) Put it on.

Thereafter, when the heat insulation shutter 34 of the low temperature heating / cooling circulation unit 30 is closed, the high temperature heating space 23 of the high temperature heating unit 20 and the circulation space of the low temperature heating / cooling circulation unit 30 are maintained. Release and open to allow 32 to communicate.

Next, the drive motor 41 of the heat flow circulation drive unit 40 is operated to rotate to rotate the circulation fan 42.

At this time, the high temperature heating heater 24 and the low temperature operating heater 31 of the high temperature heating unit 20 are operated simultaneously with the driving of the driving motor 41 so that the temperature in the high temperature furnace heating chamber 25 is 900 ° C. or lower. It is operated to heat up to the temperature of (low temperature heating temperature determined according to the process).

In this case, the high temperature heating heater 24 and the low temperature operating heater 31 are heated to the same temperature so that the internal temperature of the high temperature heating space 23 and the circulation space 32 is the same.

Then, the inverter 43 is adjusted to adjust the rotational speed of the drive motor 41 so as to meet the process purpose and to have an optimum quality in the case where the heating element 10 is manufactured (or heat treated) as a sintered body part. .

At this time, the circulation fan 42 is rotated by the driving force of the driving motor 41 of the heat flow circulation driving unit 40 while circulating the heating gas between the high temperature heating space 23 and the circulation space 32 to be heated ( 10) Heat the entire surface.

That is, the process of heating the heating target body 10 at a low temperature is a process of forming a binder, such as a lubricant, a binder, water, and the like, required for molding the heating target, from the molded body. Will be.

As shown in FIG. 3, the low temperature heating / cooling circulation is completed when the high temperature heating heater 24 and the low temperature operating heater 31 are operated to heat the heated object 10 to a low temperature of 900 ° C. or lower. The heat generation operation of the low temperature operation heater 31 of the unit 30 is stopped, and the driving of the driving motor 41 of the heat flow circulation driving unit 40 is stopped to stop the rotation of the circulation fan 42 and at the same time, the adiabatic shutter 34 is closed to operate the high temperature heating space 23 and the circulation space 32, and the cooling damper 35 of the low temperature heating / cooling circulation part 30 is opened to open the circulation space 32 and the external space. This communication causes the heating gas in the circulation space 32 to be exhausted to the outside, and the cooling gas in the external space flows into the circulation space 32 to cool the low temperature heating / cooling circulation part 30.

Here, the high temperature heating heater 24 of the high temperature heating unit 20 continuously generates heat to heat the heated object 10 while raising the inside of the high temperature furnace heating chamber 25 to a temperature of 900 to 1200 ° C. or more. The object to be heated 10 undergoes a sintering process (or a heat treatment process in which the final heat treatment is performed) to make the sintered body part.

As shown in FIG. 4, when the sintering process (or the final heat treatment process) of the heated object 10 is completed, the heating operation of the high temperature heating heater 24 of the high temperature heating unit 20 is stopped and the high temperature furnace heating chamber is completed. When the internal temperature of 25 drops below 1000 ° C., the adiabatic shutter 34 of the low temperature heating / cooling circulation part 30 is opened to operate so that the high temperature heating space 23 and the circulation space 32 communicate with each other.

Thereafter, the driving motor 41 of the heat flow circulation driving unit 40 is operated to rotate the circulation fan 42 so that the heating gas in the high temperature heating space 23 is cooled by opening the cooling damper 35 ( 32 is cooled while being introduced, and the cooling gas in the circulation space 32 flows into the high temperature heating space 23 to perform a circulation process of cooling the heating chamber 25 and the object to be heated 10 at the high temperature furnace.

At this time, by adjusting the inverter 43 of the heat flow circulation drive unit 40 by adjusting the rotational speed of the drive motor 41 to adjust the cooling flow rate for cooling.

When the temperature of the high temperature furnace heating chamber 25 and the heated object 10 decreases to about 100 ° C., the driving motor 41 of the heat flow circulation driving unit 40 is stopped to stop the rotation of the circulation fan 42. While the insulation shutter 34 is closed to operate the high temperature heating space 23 and the circulation space 32 is blocked.

Subsequently, the heated object 10 is degreased / sintered / cooled in the high temperature heating part 20, and a finished product (or a metal product in which heat treatment is finished) is taken out to complete the manufacture.

As a result, when the heated object 10 is heated at a low temperature of 900 ° C. or lower, the whole is uniformly heated due to the circulation of the heating gas, so that the degreasing efficiency of removing the binder is increased or there is no deformation of the metal product due to heat treatment. have.

In addition, there is an advantage that the low temperature operation heater 31 generates heat to operate so that the temperature change due to circulation during low temperature heating of the heating object 10 does not occur.

In addition, there is an advantage that can prevent the heat loss by blocking the high temperature heating space 23 and the circulation space 32 by the adiabatic shutter 34 when heating the heated object 10 to a high temperature of more than 1200 ℃.

In addition, the cooling damper 35 is opened to increase the cooling rate of the low temperature heating / cooling circulation unit 30, and the gas cooled in the heated object 10 in which sintering (or final heat treatment) is completed is circulated in the fan 42. By circulating in the rotation of the cooling efficiency is increased, the cooling speed is an advantage.

In the above, the present invention has been illustrated and described with reference to specific preferred embodiments, but the present invention is not limited to the above-described embodiments, and the present invention is not limited to the spirit of the present invention. Various changes and modifications will be possible by those who have the same.

1 is a cross-sectional view showing the configuration of the high-temperature sintering furnace or heat treatment furnace attached to the low temperature operating section heat flow uniformity and cooling acceleration module according to the present invention;

Figure 2 is a cross-sectional view showing a low-temperature heating process to 600 ~ 900 ℃ the heating element in Figure 1,

3 is a cross-sectional view showing a high temperature heating process of 900 ~ 1200 ℃ or more after the low temperature heating process of FIG.

4 is a cross-sectional view illustrating a cooling process after the high temperature heating process of FIG. 3.

<Description of Symbols for Main Parts of Drawings>

10: heating element 20: high temperature heating part

21: insulation member 21a: temperature measuring sensor

22: heat-resistant bottom plate 23: high temperature heating space

24: high temperature heating heater 25: high temperature furnace heating chamber

30: low temperature heating / cooling circulation part

31: Low temperature operation heater 31a: Temperature measuring sensor

32: circulation space 33: insulation

34: insulation shutter 35: cooling damper

40: heat flow circulation drive part 41: drive motor

42: circulation fan 43: inverter

100: sintering furnace or heat treatment furnace

Claims (4)

In the heat treatment furnace for heat-treating a metal product that is susceptible to deformation such as bending or sintering, which is manufactured to be a sintered body part by heating / heating the heated object 10 formed of ceramic or metal powder from low temperature to high temperature. In The high temperature at which the heat-insulating member 21 is coupled to each other to form the upper and four sides, and the heat-resistant bottom plate 22 on which the heated object 10, which is a ceramic or metal powder compact (or metal product), is mounted, is coupled to the lower portion. A high temperature heating part 20 made of a tub-type high temperature furnace heating chamber 25 into which the high temperature heating heater 24 is inserted into the heating space 23 is formed. The low-temperature operation heater 31 extends the heat insulator 33 in the form of a tube so that the circulation space 32 is installed therein, and the heat insulation shutter 34 is opened and closed by pneumatic pressure at both ends of the heat insulator 33. Forming a low temperature heating / cooling circulation part 30 having both ends of the heat insulator 33 so that both ends of the heat insulating material 33 pass through the heat insulating member 21 facing the side of the high temperature heating part 20. 23) and the circulation space 32 is formed integrally or detachably connected to open and close, The circulation fan 42 rotated by the driving force of the driving motor 41 forms a heat flow circulation drive part 40 inserted into the circulation space 32 of the low temperature heating / cooling circulation part 30, and thus the high temperature heating part. By circulating the gas in the high temperature heating space 23 and the circulation space 32 of the low temperature heating / cooling circulation part 30 of 20, the heat flow is uniform during low temperature heating and the cooling rate is shortened during cooling. High quality sintering furnace or heat treatment furnace with heat flow uniformity and cooling acceleration module The low temperature operation heater 31 of the low temperature heating / cooling circulation part 30 is composed of a plurality so that the internal temperature of the circulation space 32 is the same as the high temperature heating space 23. High quality sintering furnace or heat treatment furnace with heat flow uniformity and cooling acceleration module According to claim 1, wherein the low-temperature heating / cooling circulation portion 30 is at least one cooling damper 35 through the heat insulating material 33 to open and close the circulation space 32 and the external space in communication with one or more. High-quality sintering furnace or heat treatment furnace attached to the low temperature operating section heat flow uniformity and cooling acceleration module, characterized in that it comprises a. According to claim 1, wherein the drive motor 41 of the heat flow circulation drive unit 40 is configured such that the rotation speed is adjusted by the inverter 43 so that the gas circulation amount between the high temperature heating space 23 and the circulation space 32 is adjusted. High-temperature sintering furnace or heat treatment furnace attached to the low temperature operating section heat flow uniformity and cooling acceleration module characterized in that the.

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