Heat treatment system

Abstract

The present application provides a heat treatment system capable of reducing the consumption of gas and reducing components adversely affecting heat treatment generated due to heat treatment. The heat treatment system (10) comprises: a heat treatment furnace (1) for performing heat treatment; a reaction section (2) for reacting a first component contained in a post-heat treatment gas generated due to heat treatment in the heat treatment furnace (1) and a second component contained in a reaction gas, thereby obtaining a regenerated gas with reduced first component; a reaction gas supply section (3) for supplying the reaction gas to the reaction section (2); and a circulation passage (4) for introducing the post-heat treatment gas into the reaction section (2) and introducing the regenerated gas obtained in the reaction section (2) into the heat treatment furnace (1).

Description

Technical Field

[0001] This invention relates to heat treatment systems. Background Technology

[0002] Previously, heat treatment systems for heat-treating objects were known.

[0003] As one such heat treatment system, Patent Document 1 discloses a heat treatment system that controls the flow rate of hydrogen supplied to the heat treatment furnace based on the oxygen concentration inside the furnace detected by an oxygen sensor and a target value of the oxygen concentration. In this heat treatment system, the gas inside the heat treatment furnace is discharged through an exhaust pipe by means of the pressure inside the furnace.

[0004] However, in the heat treatment system described in Patent Document 1, gas is supplied to the heat treatment furnace from the gas supply unit during the heat treatment of the workpiece, and unwanted gas is discharged from the exhaust pipe, thus increasing the amount of gas consumed.

[0005] In contrast, Patent Document 2 discloses a heat treatment system in which a portion of the gas in the heat treatment furnace is introduced into a circulation path to remove dust from the gas, and then returned to the heat treatment furnace, thereby reducing the amount of gas consumed.

[0006] Prior art literature

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2016-001064

[0009] Patent Document 2: Japanese Patent Application Publication No. 01-184390

[0010] However, in a heat treatment furnace, substances that adversely affect the heat treatment process are sometimes generated due to the heat treatment. Therefore, if the heat treatment system described in Patent Document 2 simply introduces a portion of the gas in the heat treatment furnace into a circulation path and then returns it to the heat treatment furnace, the substances that adversely affect the heat treatment process will continuously increase in the heat treatment furnace, potentially making it difficult to perform the desired heat treatment on the workpiece. Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] The present invention addresses the aforementioned problems and aims to provide a heat treatment system that can reduce gas consumption while simultaneously reducing components that adversely affect heat treatment.

[0013] Technical solutions for solving the problem

[0014] The heat treatment system of the present invention is characterized by comprising:

[0015] A heat treatment furnace, used for heat treatment;

[0016] The reaction section is used to react the first component contained in the heat-treated gas produced by heat treatment in the heat treatment furnace with the second component contained in the reaction gas, thereby obtaining a regenerated gas with reduced first component.

[0017] A reaction gas supply unit is used to supply the reaction gas to the reaction unit; and

[0018] A circulation path is used to introduce the heat-treated gas into the reaction section and to introduce the regenerated gas obtained in the reaction section into the heat treatment furnace.

[0019] Invention Effects

[0020] According to the heat treatment system of the present invention, by supplying a reaction gas to the reaction section, a first component contained in the heat-treated gas and a second component contained in the reaction gas react, thereby obtaining a regenerated gas with a reduced first component. By returning the obtained regenerated gas to the heat treatment furnace, it is possible to reduce the first component that adversely affects the heat treatment while reducing gas consumption. Attached Figure Description

[0021] Figure 1 This is a schematic diagram illustrating the structure of the heat treatment system according to the first embodiment of the present invention.

[0022] Figure 2 This is a diagram schematically illustrating the structure of the heat treatment system according to the second embodiment of the present invention.

[0023] Figure 3 This is a diagram schematically illustrating the structure of the heat treatment system according to the third embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 1: Heat treatment furnace;

[0026] 1a: Gas outlet;

[0027] 1b: Gas inlet;

[0028] 2: Reaction section;

[0029] 2a: Inlet port;

[0030] 2b: Outlet port;

[0031] 3: Reaction gas supply section;

[0032] 4: Circulatory pathway;

[0033] 5: Air supply section;

[0034] 6: Sensors;

[0035] 7: Control Unit;

[0036] 10, 10A, 10B: Heat treatment system;

[0037] 11: Exhaust pipe;

[0038] 20: Lowering section;

[0039] 30: Gas amplifier. Detailed Implementation

[0040] The following describes embodiments of the present invention and provides a detailed description of its features.

[0041] <First Embodiment>

[0042] Figure 1 This diagram schematically illustrates the structure of the heat treatment system 10 according to the first embodiment of the present invention. The heat treatment system 10 in the first embodiment includes a heat treatment furnace 1, a reaction section 2, a reaction gas supply section 3, and a circulation passage 4.

[0043] Heat treatment furnace 1 is a furnace used for heat treatment of the workpiece, and includes a heating unit H1 such as a heater. In this embodiment, heat treatment furnace 1 is a batch-type heat treatment furnace. The type of heat treatment performed in heat treatment furnace 1 is not particularly limited; for example, it can be a firing process for manufacturing ceramic electronic components, a degreasing process, or a drying process for the workpiece. The volume of heat treatment furnace 1 is, for example, 0.5 m³. 3 Above and 10m 3 the following.

[0044] Heat treatment is performed in heat treatment furnace 1, thereby generating a heat-treated gas containing a first component. The first component is a component that hinders heat treatment in heat treatment furnace 1, such as H2, CO, CO2, etc. Furthermore, the first component that hinders heat treatment varies depending on the nature of the heat treatment. For example, in one heat treatment system, CO2 is the first component, but in another heat treatment system, CO2 may not hinder heat treatment and therefore may not be the first component.

[0045] The heat treatment furnace 1 is provided with an exhaust pipe 11, which is used to discharge unwanted gases and keep the amount of gas in the heat treatment system 10 constant.

[0046] The reaction section 2 is used to react the first component contained in the heat-treated gas produced by heat treatment in the heat treatment furnace 1 with the second component contained in the reaction gas, thereby obtaining a regenerated gas with a reduced first component. For example, if the first component is H2, the second component is set to O2. That is, as shown in the following formula (1), by reacting H2 and O2, a regenerated gas containing H2O as a third component is obtained.

[0047] 2H₂ + O₂ = 2H₂O (1)

[0048] Furthermore, when the first component is CO, the second component is set to O2. That is, CO and O2 are reacted by the reaction formula shown in equation (2) below, thereby obtaining a regenerated gas containing CO2 as the third component.

[0049] 2CO + O2 = 2CO2 (2)

[0050] Furthermore, when the first component is a solvent such as acetone or terpineol, the second component is set to O2. That is, by burning acetone or terpineol, a regenerated gas with reduced acetone or terpineol content is obtained. However, the second component used to burn acetone or terpineol is not limited to O2, and components containing oxygen atoms such as air, H2O, and CO2 can be used.

[0051] In this way, the second component uses an ingredient that can react with the first component, thereby causing the first component to disappear or decrease.

[0052] The reaction section 2 is equipped with a heating unit H2 such as a heater, and is configured to be able to perform independent temperature control separately from the heat treatment furnace 1. The reaction section 2, which is used to react the first component and the second component, does not need to have a large volume like the heat treatment furnace 1. For example, it is set to a size of 10% to 20% of the volume of the heat treatment furnace 1.

[0053] In this embodiment, the reaction section 2 has: an inlet 2a for introducing heat-treated gas; and an outlet 2b, independent of the inlet 2a, for discharging regenerated gas to the circulation passage 4.

[0054] The reaction gas supply unit 3 supplies reaction gas containing the second component to the reaction unit 2. The flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 is controlled by the control unit 7, which will be described later.

[0055] The circulation passage 4 is a gas pipe used to introduce the heat-treated gas generated in the heat treatment furnace 1 into the reaction section 2, and to introduce the regenerated gas obtained in the reaction section 2 into the heat treatment furnace 1. The circulation passage 4 connects the gas outlet 1a of the heat treatment furnace 1 with the inlet 2a of the reaction section 2, and connects the outlet 2b of the reaction section 2 with the gas inlet 1b of the heat treatment furnace 1.

[0056] The heat treatment system 10 in this embodiment includes an air supply unit 5, which circulates gas through a circulation passage 4 by supplying air. Specifically, the air supply unit 5 generates a gas flow such that the heat-treated gas is introduced from the heat treatment furnace 1 to the reaction section 2 via the circulation passage 4, and the regenerated gas obtained in the reaction section 2 is introduced back into the heat treatment furnace 1. The air supply unit 5 is, for example, a blower, and is provided in the circulation passage 4. By circulating the gas through the air supply unit 5, a gas flow of at least 10 times and less than 100 times the amount of gas introduced into the heat treatment system 10 can be generated compared to a structure without the air supply unit 5. By increasing the gas flow rate, the amount of gas required for heat treatment can be reduced; therefore, in this embodiment, for example, the amount of gas introduced into the heat treatment system 10 can be reduced to about one-tenth.

[0057] In addition, if the regenerated gas obtained in the reaction section 2 is at a high temperature, the regenerated gas can be cooled and returned to the heat treatment furnace 1.

[0058] The heat treatment system 10 in this embodiment further includes: a sensor 6 for detecting the presence and concentration of at least one of the first component, the second component, and the third component contained in the regenerated gas; and a control unit 7 for controlling the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 based on the detection result of the sensor 6.

[0059] Sensor 6 is a sensor used to determine the amount of the first component contained in the regenerated gas introduced into the heat treatment furnace 1. It is installed between the outlet 2b of the reaction section 2 in the circulation passage 4 and the gas inlet 1b of the heat treatment furnace 1, for example, near the gas inlet 1b of the heat treatment furnace 1. In order to determine the degree of reduction of the first component, it is preferable to detect at least one of the presence or absence and concentration of the first component contained in the regenerated gas by sensor 6.

[0060] However, if the sensor 6 has a higher detection accuracy for the second or third component than for the first component, it is also possible to detect at least one of the presence or concentration of the second or third component contained in the regenerated gas using the sensor 6. Since the second component in the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 reacts with the first component and disappears, the concentration of the first component can be indirectly detected, for example, by detecting the concentration of the second component contained in the regenerated gas using the sensor 6. Furthermore, the third component is generated through the reaction of the first and second components, so information related to the concentration of the first component can be indirectly obtained, for example, by detecting the concentration of the third component contained in the regenerated gas using the sensor 6. To improve detection accuracy, the sensor 6 can also detect any two or three of the first, second, and third components contained in the regenerated gas. Alternatively, the sensor 6 can be placed at multiple locations, and the average of multiple detection values ​​can be calculated to obtain a more accurate measurement result.

[0061] The target gas detected by sensor 6 is, for example, O2, H2, H2O, CO2, SO2, SO, etc. The temperature of the target gas when using sensor 6 is, for example, above 20°C and below 1400°C. As sensor 6, for example, a semiconductor gas sensor, a solid electrolyte gas sensor, or a non-dispersive infrared gas sensor can be used. The internal resistance of sensor 6 is, for example, below 1000kΩ.

[0062] Alternatively, a recorder can be connected to sensor 6 to record the detection results of the target gas. In this case, the internal resistance of the recorder is, for example, 1 MΩ or higher and 1000 MΩ or lower. The gas detection system including sensor 6 and recorder can also include circuit components such as analog signal converters, signal amplifiers, noise filters, digital signal converters, resistors, and isolators.

[0063] Alternatively, other gas sensors can be installed in the heat treatment furnace 1. In this case, the presence or absence of the target gas, concentration or partial pressure can be determined by other gas sensors, and the gas introduction rate, wind speed, temperature and pressure inside the heat treatment furnace 1 can be adjusted based on the output of other gas sensors or recorders and the digitally processed values ​​from that output, or the emergency stop or maintenance of the heat treatment furnace 1 can be indicated.

[0064] As described above, the control unit 7 controls the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 based on the detection results of the sensor 6. Specifically, the control unit 7 determines the target flow rate of the reaction gas based on at least one of the presence and concentration of the first component, the second component, and the third component detected by the sensor 6, and controls the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 to become the target flow rate. In other words, the control unit 7 determines the target flow rate of the reaction gas containing the second component for reacting with the first component based on at least one of the presence and concentration of the first component detected directly or indirectly by the sensor 6, and controls the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 to become the target flow rate. Therefore, the control unit 7 can be configured to have a mass flow controller, which can control the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 to become the target flow rate.

[0065] In this way, the control unit 7 controls the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 based on the detection result of the sensor 6, thereby enabling appropriate control of the flow rate of the reaction gas containing the second component, which is used to react with the first component contained in the heat-treated gas, and thus effectively reducing the first component contained in the heat-treated gas.

[0066] According to the heat treatment system 10 of this embodiment, a regenerated gas with a reduced first component is obtained by reacting a first component contained in the heat-treated gas produced by heat treatment in the heat treatment furnace 1 with a second component contained in the reaction gas supplied to the reaction section 2. By returning the obtained regenerated gas to the heat treatment furnace 1, it is possible to reduce the amount of gas newly introduced into the heat treatment system 10 while reducing the first component that adversely affects heat treatment. As an example, when the first component is a solvent such as acetone or terpineol, the concentration of the solvent contained in the regenerated gas obtained in the reaction section 2 can be reduced to 5% or less.

[0067] <Second Implementation>

[0068] Figure 2 This diagram schematically illustrates the structure of the heat treatment system 10A in the second embodiment. Compared to the structure of the heat treatment system 10 in the first embodiment, the heat treatment system 10A in the second embodiment further includes a lowering section 20.

[0069] The reducing section 20 reduces the third component generated by the reaction of the first and second components from the regenerated gas obtained in the reaction section 2 by at least one of the following methods: filtration, separation, adsorption, condensation and dissolution.

[0070] Here, as an example, a reflow soldering process is performed in a heat treatment furnace 1, and the first component is solder flux, the second component is O2, and the third component of the regeneration gas is water vapor (H2O). That is, by burning the flux, a regeneration gas with reduced flux content is obtained. However, the second component used to burn the flux is not limited to O2; components containing oxygen atoms, such as air, H2O, and CO2, can be used.

[0071] In this embodiment, the lowering section 20 cools the regeneration gas introduced from the reaction section 2 to the heat treatment furnace 1 via the circulation passage 4, thereby condensing water vapor, which is the third component, and recovering the water (H2O) obtained through condensation. For example, a double-tube structure with a cooling pipe provided as the lowering section 20 on the outside of the circulation passage 4 between the outlet 2b of the reaction section 2 and the gas inlet 1b of the heat treatment furnace 1, is provided, and cooling water flows in the cooling pipe to cool the regeneration gas flowing through the circulation passage 4 on the inside of the double-tube structure. A collection device is provided in the cooling pipe to recover the water obtained through condensation.

[0072] According to this structure, if the third component contained in the regenerated gas hinders heat treatment in the heat treatment furnace 1, the regenerated gas can be introduced into the heat treatment furnace 1 after the third component contained in the regenerated gas is reduced by the reducing section 20. That is, even if a third component that hinders heat treatment is generated when the first component, which is a component that hinders heat treatment, is reduced by the reaction of the reaction section 2, the regenerated gas with the reduced third component can be introduced into the heat treatment furnace 1. Thus, even if the regenerated gas introduced into the heat treatment furnace 1 contains a third component that hinders heat treatment, the amount of gas newly introduced into the heat treatment system 10A can be reduced while the first component and the third component that are generated due to heat treatment and have an adverse effect on heat treatment are reduced.

[0073] Furthermore, in the reduction section 20, if not only the third component but also the first component can be reduced by at least one method selected from filtration, separation, adsorption, condensation, and dissolution, the amount of the first component reacting in the reaction section 2 can also be reduced, and the remaining amount can be reduced in the reduction section 20. For example, if the first component is reduced by burning it in the reaction section 2, and the first component is not completely burned in the reaction section 2, but is reduced in the reduction section 20 by methods such as condensation, the amount of O2, which is the second component, supplied to the reaction section 2 can be reduced.

[0074] <Third Implementation>

[0075] Figure 3This diagram schematically illustrates the structure of the heat treatment system 10B in the third embodiment. The heat treatment system 10B in this embodiment, like the heat treatment system 10 in the first embodiment, includes a heat treatment furnace 1, a reaction section 2, a reaction gas supply section 3, a circulation path 4, a sensor 6, and a control section 7.

[0076] In this embodiment, the heat treatment furnace 1 is a continuous heat treatment furnace such as a muffle furnace or a tunnel furnace. Additionally, Figure 3 A cross-section orthogonal to the extension direction of the continuous heat treatment furnace 1 is schematically shown. A circulation passage 4 is connected to the heat treatment furnace 1. Specifically, one end of the circulation passage 4 is connected to the gas outlet 1a of the heat treatment furnace 1, and the other end is connected to the gas inlet 1b of the heat treatment furnace 1.

[0077] The heat treatment system 10B in this embodiment also includes a gas amplifier 30, which circulates gas through the circulation passage 4 using compressed gas. The gas amplifier 30 is installed in the circulation passage 4 and configured to amplify the input gas volume to, for example, a factor of 2 or more but less than 10 times for output. The compressed gas is, for example, compressed air. In this embodiment, the heat treatment furnace 1, the circulation passage 4, and the gas amplifier 30 are installed within a space where a heating unit H3, such as a heater, is installed. Therefore, the gas amplifier 30 is installed instead of a blower as a heat-resistant component. However, an air supply unit 5, such as a blower, may also be installed in the circulation passage 4.

[0078] In this embodiment, the circulation passage 4 is configured as a reaction section 2. That is, the reaction gas supply section 3 supplies reaction gas containing the second component to the circulation passage 4. The second component supplied to the circulation passage 4 reacts with the first component contained in the heat-treated gas generated due to heat treatment in the heat treatment furnace 1 to obtain a regenerated gas with reduced first component.

[0079] For example, the first component is H2 and the second component is O2. In this case, in the circulation path 4, H2, which is the first component, and O2, which is the second component, react to obtain a regenerated gas containing H2O, which is the third component.

[0080] Sensor 6 is located near the outlet of the circulation passage 4, that is, near the gas inlet 1b of the heat treatment furnace 1. In this embodiment, sensor 6 also detects the presence and concentration of at least one of the first, second, and third components contained in the regenerated gas.

[0081] However, sensor 6 can also be installed upstream of the circulation path 4, that is, between the location where the reaction gas is supplied to the circulation path 4 by the reaction gas supply unit 3 and the gas amplifier 30. When sensor 6 is installed in the portion of the circulation path 4 between the gas amplifier 30 and the gas inlet 1b of the heat treatment furnace 1, the gas detection accuracy of sensor 6 becomes unstable due to the gas flow caused by compressed air in the gas amplifier 30. In such cases, by installing sensor 6 between the location where the reaction gas is supplied to the circulation path 4 by the reaction gas supply unit 3 and the gas amplifier 30, the gas detection accuracy of sensor 6 can be improved.

[0082] Furthermore, sensors 6 can be installed between the location where the reaction gas is supplied from the reaction gas supply unit 3 to the circulation passage 4 and the gas amplifier 30, and between the gas amplifier 30 and the gas inlet 1b of the heat treatment furnace 1. In this case, the control unit 7 can control the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 based on the detection results of the sensors 6 installed at both locations, thus enabling more precise control of the flow rate of the reaction gas supplied to the reaction unit 2. For example, when the gas concentration is detected by the sensor 6, the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 can be controlled based on the difference or average value of the gas concentrations detected by the two sensors 6.

[0083] This invention is not limited to the embodiments described above, and various applications and modifications can be applied within the scope of this invention. Furthermore, the characteristic structures described in each embodiment can be appropriately combined.

Claims

1. A heat treatment system, characterized in that, have: Heat treatment furnace, used for heat treatment of ceramic electronic components; The reaction section is used to react the first component contained in the heat-treated gas produced by heat treatment in the heat treatment furnace with the second component contained in the reaction gas, thereby obtaining a regenerated gas with reduced first component. A reaction gas supply unit is used to supply the reaction gas to the reaction unit; A circulation path is provided for introducing the heat-treated gas into the reaction section and introducing the regenerated gas obtained in the reaction section into the heat treatment furnace; A sensor is used to detect the presence and concentration of at least one of the following components: the first component, the second component, and the third component generated by the reaction of the first component and the second component in the regenerated gas; and The control unit is used to control the flow rate of the reactant gas supplied from the reactant gas supply unit to the reaction unit based on the detection results of the sensor. The sensor is positioned between the location where the reaction gas is supplied to the reaction section and the location where the regeneration gas is supplied to the heat treatment furnace from the circulation path, in the direction of the flow of the heat-treated gas in the reaction section and the circulation path. The heat treatment system also includes: The reduction section reduces the third component generated from the regenerated gas through the reaction of the first and second components by at least one of the following methods: filtration, separation, adsorption, condensation, and dissolution. The heat treatment includes firing and degreasing.

2. The heat treatment system according to claim 1, characterized in that, The reaction section has: An inlet is provided for introducing the heat-treated gas; and An outlet, independent of the inlet, is used to export the regenerated gas into the circulation path.

3. The heat treatment system according to claim 1 or 2, characterized in that, It also has: An air supply unit is used to circulate gas through the circulation passage by supplying air.

4. The heat treatment system according to claim 1 or 2, characterized in that, The circulation pathway constitutes the reaction section.

5. The heat treatment system according to claim 4, characterized in that, It also has: A gas amplifier for using compressed gas to circulate gas through the circulation path.

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