JP2022156337A - Heat treatment system - Google Patents

Abstract

To reduce components generated by heat treatment and exerting harmful effects to heat treatment while reducing the consumption of a gas.SOLUTION: A heat treatment system 10 comprises: a heat treatment furnace 1 for performing heat treatment; a reaction part 2 in which a first component comprised in a gas after the heat treatment generated by heat treatment in the heat treatment furnace 1 and a second component comprised in a reaction gas are reacted to obtain a regenerated gas in which the first component is reduced; a reaction gas feed part 3 for feeding the reaction gas to the reaction part 2; and a circulation passage 4 for introducing the gas after the heat treatment into the reaction part 2 and introducing the generated gas obtained in the reaction part 2 into the heat treatment furnace 1.SELECTED DRAWING: Figure 1

Description

The present invention relates to thermal processing systems.

2. Description of the Related Art Conventionally, a heat treatment system that heats an object to be treated is known.

As one such heat treatment system, Patent Document 1 discloses that the flow rate of hydrogen supplied into the heat treatment furnace is adjusted based on the oxygen concentration in the heat treatment furnace detected by an oxygen sensor and the target value of the oxygen concentration. A controlled thermal processing system is disclosed. This heat treatment system is configured such that the gas inside the heat treatment furnace is exhausted through the exhaust pipe by the pressure inside the heat treatment furnace.

However, the heat treatment system described in Patent Document 1 is configured to supply gas from the gas supply unit into the heat treatment furnace and discharge unnecessary gas from the exhaust pipe while performing the heat treatment on the object to be treated. As a result, gas consumption increases.

On the other hand, in Patent Document 2, after part of the gas in the heat treatment furnace is introduced into the circulation path to remove floating dust in the gas, it is returned to the heat treatment furnace, thereby reducing the gas consumption. A reducing heat treatment system is disclosed.

JP 2016-001064 A JP-A-01-184390

However, in a heat treatment furnace, the heat treatment may produce substances whose constituents adversely affect the heat treatment. For this reason, in the heat treatment system described in Patent Document 2, in a configuration in which a part of the gas in the heat treatment furnace is introduced into the circulation path and returned to the heat treatment furnace again, the substance of the component that adversely affects the heat treatment continues to increase in the heat treatment furnace, making it difficult to perform the desired heat treatment on the workpiece.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat treatment system capable of reducing components that adversely affect heat treatment while reducing gas consumption.

The heat treatment system of the present invention is
a heat treatment furnace for performing heat treatment;
A regeneration gas in which the first component is reduced is obtained by reacting the first component contained in the gas after heat treatment generated by the heat treatment in the heat treatment furnace with the second component contained in the reaction gas. a reaction section for
a reaction gas supply unit for supplying the reaction gas to the reaction unit;
a circulation path for introducing the post-heat treatment gas into the reaction section and introducing the regeneration gas obtained in the reaction section into the heat treatment furnace;
characterized by comprising

According to the heat treatment system of the present invention, the reactant gas is supplied to the reaction section, and the first component contained in the post-heat treatment gas generated by the heat treatment is reacted with the second component contained in the reactant gas. A regeneration gas having a reduced first component is obtained. By returning the obtained regeneration gas to the heat treatment furnace, it is possible to reduce the amount of the first component that adversely affects the heat treatment while reducing gas consumption.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the heat processing system in the 1st Embodiment of this invention. It is a figure which shows typically the structure of the heat processing system in the 2nd Embodiment of this invention. It is a figure which shows typically the structure of the heat processing system in the 3rd Embodiment of this invention.

Embodiments of the present invention will be shown below to specifically describe features of the present invention.

<First embodiment>
FIG. 1 is a diagram schematically showing the configuration of a heat treatment system 10 according to the first embodiment of the invention. A heat treatment system 10 according to the first embodiment includes a heat treatment furnace 1 , a reaction section 2 , a reaction gas supply section 3 , and a circulation path 4 .

The heat treatment furnace 1 is a furnace for heat-treating an object to be treated, and includes heating means H1 such as a heater. The heat treatment furnace 1 in this embodiment is a batch type heat treatment furnace. The type of heat treatment performed in the heat treatment furnace 1 is not particularly limited, and may be, for example, firing treatment or degreasing treatment for manufacturing ceramic electronic components, or drying treatment for the object to be treated. The volume of the heat treatment furnace 1 is, for example, 0.5 m ³ or more and 10 m ³ or less.

By performing the heat treatment in the heat treatment furnace 1, a post-heat treatment gas containing the first component is generated. The first component is a component that inhibits the heat treatment in the heat treatment furnace 1, such as H ₂ , CO, CO ₂ and the like. Note that the first component, which is a component that inhibits the heat treatment, varies depending on the content of the heat treatment. For example, in one heat treatment system _CO2 may be the first component, but in another heat treatment system _CO2 may not interfere with the heat treatment and may not be the first component.

The heat treatment furnace 1 is provided with an exhaust pipe 11 for discharging unnecessary gas to keep the amount of gas in the heat treatment system 10 constant.

The reaction part 2 reacts the first component contained in the post-heat treatment gas generated by the heat treatment in the heat treatment furnace 1 with the second component contained in the reaction gas, thereby reducing the first component. It is for obtaining regeneration gas. For example, if the first component is H2, then the _second component is _O2 . That is, as shown in the following formula (1), by reacting H ₂ and O ₂ , regeneration gas containing H ₂ O as the third component is obtained.
2H2 _{+ O2 =} 2H2O (1)

Also, when the first component is CO, the second component is O ₂ . That is, by reacting CO and O ₂ according to the reaction formula shown in the following formula (2), regeneration gas containing CO ₂ as the third component is obtained.
2CO+ _O2 =2CO2 ( ₂ )

Also, when the first component is a solvent such as acetone or terpineol, the second component is O ₂ . That is, by burning acetone and terpineol, regeneration gas with reduced acetone and terpineol can be obtained. However, the second component for burning acetone or terpineol is not limited to O ₂ , and it is possible to use a component containing oxygen atoms such as air, H ₂ O, CO ₂ .

Thus, the second component uses a component that can react with the first component to eliminate or reduce the first component.

The reaction section 2 is equipped with a heating means H2 such as a heater, and is configured to be capable of temperature control independently from the heat treatment furnace 1 . The reaction section 2 for reacting the first component and the second component does not require a volume as large as that of the heat treatment furnace 1. For example, the volume of the heat treatment furnace 1 is 10% or more and 20% or less.

In this embodiment, the reaction section 2 has an inlet 2a for introducing the post-heat treatment gas, and an outlet 2b for leading the regeneration gas to the circulation path 4 in addition to the inlet 2a.

The reactive gas supply unit 3 supplies the reactive 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.

The circulation path 4 is a gas pipe for introducing the post-heat treatment gas generated in the heat treatment furnace 1 into the reaction section 2 and introducing the regeneration gas obtained in the reaction section 2 into the heat treatment furnace 1 . The circulation path 4 connects between the gas outlet 1 a of the heat treatment furnace 1 and the inlet 2 a of the reaction section 2 and between the outlet 2 b of the reaction section 2 and the gas inlet 1 b of the heat treatment furnace 1 .

The heat treatment system 10 in this embodiment includes an air blower 5 for circulating gas through the circulation path 4 by air blowing. That is, the blower unit 5 blows the post-heat treatment gas from the heat treatment furnace 1 to the reaction unit 2 through the circulation path 4, and controls the flow of the gas that introduces the regeneration gas obtained in the reaction unit 2 into the heat treatment furnace 1. Generate. The blower unit 5 is, for example, a fan, and is provided in the circulation path 4 . By circulating the gas by blowing air from the air blowing unit 5, a gas flow of, for example, 10 times or more and 100 times or less the amount of gas introduced into the heat treatment system 10 compared to a configuration without the air blowing unit 5. can be generated. By increasing the flow rate of the gas, the amount of gas required for heat treatment can be reduced. Therefore, in the present embodiment, for example, the amount of gas to be introduced into the heat treatment system 10 can be reduced to about one-tenth.

If the regeneration gas obtained in the reaction section 2 is at a high temperature, the regeneration gas may be cooled and then returned to the heat treatment furnace 1 .

The heat treatment system 10 in this embodiment detects at least one of the presence and concentration of at least one of the first component, the second component, and the third component contained in the regeneration 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 .

The sensor 6 is a sensor for ascertaining the amount of the first component contained in the regeneration gas introduced into the heat treatment furnace 1 . It is provided between the gas inlet 1b, for example, near the gas inlet 1b of the heat treatment furnace 1. In order to grasp the degree of reduction of the first component, it is preferable that the sensor 6 detects at least one of the presence and concentration of the first component contained in the regeneration gas.

However, if the detection accuracy of the second component or the third component by the sensor 6 is higher than that of the first component, the sensor 6 detects the second component or the third component contained in the regeneration gas. At least one of the presence/absence and the concentration of is detected. The second component in the reaction gas supplied to the reaction unit 2 by the reaction gas supply unit 3 reacts with the first component and disappears. 6 can indirectly detect the concentration of the first component. In addition, since the third component is generated by the reaction of the first component and the second component, for example, by detecting the concentration of the third component contained in the regeneration gas with the sensor 6, the Information regarding the concentration of the first component can be obtained. In order to improve the detection accuracy, the sensor 6 may detect any two or three of the first component, the second component, and the third component contained in the regeneration gas. . Moreover, by providing the sensors 6 at a plurality of locations and obtaining an average value of a plurality of detection values, a more accurate measurement result may be obtained.

Gases to be detected by the sensor 6 are, for example, O ₂ , H ₂ , H ₂ O, CO ₂ , SO ₂ , SO and the like. The temperature of the gas to be detected when the sensor 6 is used is, for example, 20° C. or higher and 1400° C. or lower. As the 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 the sensor 6 is, for example, 1000 kΩ or less.

A recorder may be connected to the sensor 6 to record the detection result of the gas to be detected in the recorder. In that case, the internal resistance of the recorder is, for example, 1 MΩ or more and 1000 MΩ or less. The gas detection system including sensor 6 and recorder may include electrical circuit components such as analog signal converters, signal amplifiers, noise filters, digital signal converters, resistors and isolators.

Another gas sensor may be separately provided in the heat treatment furnace 1 . In that case, another gas sensor is used to determine the presence or absence of the gas to be detected and to measure the concentration or partial pressure. 1 gas introduction amount, wind speed, temperature and pressure in the heat treatment furnace 1 may be adjusted, and an emergency stop or maintenance of the heat treatment furnace 1 may be instructed.

As described above, the control section 7 controls the flow rate of the reaction gas supplied from the reaction gas supply section 3 to the reaction section 2 based on the detection result 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. is determined, and the flow rate of the reaction gas supplied from the reaction gas supply unit 3 to the reaction unit 2 is controlled so as to be the target flow rate. In other words, based on at least one of the presence or absence and concentration of the first component directly or indirectly detected by the sensor 6, the control unit 7 causes the second component to react with the first component. is determined, and the flow rate of the reaction gas supplied from the reaction gas supply section 3 to the reaction section 2 is controlled so as to be the target flow rate. Therefore, the control unit 7 can be configured to include a mass flow controller capable of controlling the flow rate of the reactant gas supplied from the reactant gas supply unit 3 to the reaction unit 2 to the target flow rate.

In this manner, 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, whereby the first component contained in the post-heat treatment gas and Since the flow rate of the reaction gas containing the second component for reaction can be appropriately controlled, the first component contained in the post-heat treatment gas can be effectively reduced.

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

<Second embodiment>
FIG. 2 is a diagram schematically showing the configuration of a heat treatment system 10A according to the second embodiment. A heat treatment system 10A according to the second embodiment further includes a reduction unit 20 in addition to the structure of the heat treatment system 10 according to the first embodiment.

The reduction unit 20 removes the third component produced by the reaction of the first component and the second component from the regeneration gas obtained in the reaction unit 2 by filtration, separation, adsorption, condensation, and dissolution. is reduced by at least one method of

Here, as an example, solder reflow treatment is performed in the heat treatment furnace 1, the first component is flux as a soldering accelerator, the second component is O ₂ , and the third component contained in the regeneration gas is water vapor ( H ₂ O). That is, by burning the flux, a regeneration gas with reduced flux can be obtained. However, the second component for burning the flux is not limited to O ₂ , and it is possible to use a component containing oxygen atoms such as air, H ₂ O, CO ₂ .

The reduction unit 20 in the present embodiment cools the regeneration gas introduced from the reaction unit 2 into the heat treatment furnace 1 through the circulation path 4, thereby condensing water vapor, which is the third component, to obtain Water (H ₂ O) is recovered. For example, a double pipe structure in which a cooling pipe is provided as a reducing part 20 outside the circulation path 4 between the outlet 2b of the reaction part 2 and the gas inlet 1b of the heat treatment furnace 1, and cooling water is supplied to the cooling pipe. to cool the regeneration gas flowing through the circulation path 4 inside the double tube. The cooling pipe is provided with a trap device to collect water obtained by condensation.

According to this configuration, when the third component contained in the regeneration gas interferes with the heat treatment in the heat treatment furnace 1, the third component contained in the regeneration gas is reduced in the reducing unit 20 before being transferred to the heat treatment furnace 1. can be introduced with That is, even when the third component, which is a component that inhibits the heat treatment, is generated when the first component, which is a component that inhibits the heat treatment, is reduced by the reaction in the reaction unit 2, the third component is reduced. A regeneration gas can be introduced into the heat treatment furnace 1 . As a result, even when the regeneration gas introduced into the heat treatment furnace 1 contains the third component that inhibits the heat treatment, the amount of gas newly introduced into the heat treatment system 10A is reduced, and the The first component and the third component that adversely affect heat treatment can be reduced.

In addition, in the reduction unit 20, if not only the third component but also the first component can be reduced by at least one method of filtration, separation, adsorption, condensation, and dissolution, the reaction It is also possible to reduce the amount of reacting the first component in section 2 and reduce the remainder in reduction section 20 . For example, when the first component is reduced by burning the first component in the reaction section 2, the first component is not completely burned in the reaction section 2 and is reduced in the reduction section 20 by a method such as condensation. The amount of O ₂ , which is the second component, supplied to the reaction section 2 can be reduced.

<Third Embodiment>
FIG. 3 is a diagram schematically showing the configuration of a heat treatment system 10B according to the third embodiment. As with the heat treatment system 10 of the first embodiment, the heat treatment system 10B of the present embodiment also 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.

The heat treatment furnace 1 in this embodiment is a continuous heat treatment furnace such as a muffle furnace or a tunnel furnace. In addition, FIG. 3 schematically shows a cross section perpendicular to the stretching direction of the continuous heat treatment furnace 1 . A circulation path 4 is connected to the heat treatment furnace 1 . Specifically, one end of the circulation path 4 is connected to the gas outlet 1 a of the heat treatment furnace 1 , and the other end is connected to the gas inlet 1 b of the heat treatment furnace 1 .

The heat treatment system 10B in this embodiment further comprises a gas amplifier 30 for circulating gas through the circuit 4 using compressed gas. The gas amplifier 30 is provided in the circulation path 4, and is configured to be able to amplify the input gas amount to, for example, 2 times or more and 10 times or less and output the amplified amount. Compressed gas is, for example, compressed air. In this embodiment, the heat treatment furnace 1, the circulation path 4 and the gas amplifier 30 are provided in a space provided with a heating means H3 such as a heater. Therefore, instead of the fan, a gas amplifier 30 is provided as a heat-resistant member. However, the circulation path 4 may be provided with an air blower 5 such as a fan.

In this embodiment, the circulation path 4 is configured as the reaction section 2 . That is, the reaction gas supply unit 3 supplies the reaction gas containing the second component to the circulation path 4 . The second component supplied to the circulation path 4 reacts with the first component contained in the post-heat treatment gas generated by the heat treatment in the heat treatment furnace 1 to obtain a regeneration gas in which the first component is reduced.

For example, the first component is H2 and the _second component is _O2 . In this case, H ₂ as the first component and O ₂ as the second component react in the circulation path 4 to obtain regeneration gas containing H ₂ O as the third component.

The sensor 6 is provided near the exit of the circulation path 4 , that is, near the gas inlet 1 b of the heat treatment furnace 1 . Also in this embodiment, the sensor 6 detects at least one of the presence and concentration of at least one of the first component, the second component, and the third component contained in the regeneration gas.

However, the sensor 6 may be provided upstream of the circulation path 4 , that is, between the position where the reaction gas is supplied to the circulation path 4 by the reaction gas supply section 3 and the gas amplifier 30 . In the case where the sensor 6 is provided in the portion between the gas amplifier 30 and the gas inlet 1b of the heat treatment furnace 1 in the circulation path 4, the gas flow using the compressed air from the gas amplifier 30 affects the gas detection accuracy of the sensor 6. may become unstable. In such a case, by providing the sensor 6 between the position where the reaction gas is supplied to the circulation path 4 by the reaction gas supply unit 3 and the gas amplifier 30, the accuracy of gas detection by the sensor 6 can be improved. can.

Sensors 6 are provided between the gas amplifier 30 and the position where the reaction gas is supplied to the circulation path 4 by the reaction gas supply unit 3, and between the gas amplifier 30 and the gas inlet 1b of the heat treatment furnace 1, respectively. You may do so. 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 provided at two locations. The flow rate of the reaction gas supplied to the reaction section 2 can be controlled. 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 is based on the difference or average value of the gas concentrations detected by the two sensors 6. can be controlled.

The present invention is not limited to the above embodiments, and various applications and modifications can be made within the scope of the present invention. Further, the characteristic configurations described in each embodiment can be combined as appropriate.

1 Heat Treatment Furnace 1a Gas Outlet 1b Gas Inlet 2 Reaction Part 2a Inlet 2b Outlet 3 Reaction Gas Supply Part 4 Circulation Path 5 Blower Part 6 Sensor 7 Control Part 10, 10A, 10B Heat Treatment System 11 Exhaust Pipe 20 Reduction Part 30 Gas Amplifier

Claims (7)

a heat treatment furnace for performing heat treatment;
A regeneration gas in which the first component is reduced is obtained by reacting the first component contained in the gas after heat treatment generated by the heat treatment in the heat treatment furnace with the second component contained in the reaction gas. a reaction section for
a reaction gas supply unit for supplying the reaction gas to the reaction unit;
a circulation path for introducing the post-heat treatment gas into the reaction section and introducing the regeneration gas obtained in the reaction section into the heat treatment furnace;
A heat treatment system comprising: 2. The reaction section has an inlet for introducing the gas after heat treatment, and an outlet for leading the regeneration gas to the circulation path, separate from the inlet. The heat treatment system according to . at least one of the first component, the second component, and the third component produced by the reaction of the first component and the second component contained in the regeneration gas; a sensor for detecting at least one of presence or absence and concentration;
a control unit for controlling the flow rate of the reaction gas supplied from the reaction gas supply unit to the reaction unit based on the detection result of the sensor;
3. The thermal processing system of claim 1 or 2, further comprising: reducing, from the regeneration gas, a third component produced by reaction of the first component and the second component by at least one of filtering, separating, adsorbing, condensing, and dissolving. The heat treatment system according to any one of claims 1 to 3, further comprising a reducing section. The heat treatment system according to any one of claims 1 to 4, further comprising a blower for blowing gas to circulate through the circulation path. The heat treatment system according to any one of claims 1 to 5, wherein the circulation path is configured as the reaction section. 7. The thermal processing system of claim 6, further comprising a gas amplifier for circulating gas through said circuit using compressed gas.

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