Heat treatment apparatus and temperature measuring apparatus

Abstract

To reduce the fine particles adhering to a device.SOLUTION: A heat treatment apparatus includes: a processing chamber; a furnace wall that surrounds the processing chamber and has a through hole; a device positioned at the through hole; and an ultrasonic generator that emits ultrasonic toward the device.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat treatment apparatus and a temperature measurement apparatus. [Background technology]

[0002] In heat treatment equipment for carburization, thermometers using thermocouples are used to measure the temperature inside the furnace. In such heat treatment equipment, the thermometer is exposed to a gas containing carbon, which can cause carbon particles to adhere to the thermometer and lead to errors in the measurement. For this reason, for example, a thermometer with a protective tube is used, which has a protective tube in which a thermocouple is attached and an exhaust tube surrounding the protective tube (Patent Document 1). With such a thermometer with a protective tube, carbon particles can be discharged by purge gas flowing through an air passage formed between the protective tube and the exhaust tube, reducing errors in the measurement. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 54-006981 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since it is difficult to remove particles smaller than a certain particle size using a purge gas, the particles may not be removed from the surroundings of devices such as thermometers, which may result in the particles adhering to the devices, potentially causing errors in the measurement values.

[0005] Therefore, an object of the present disclosure is to reduce the amount of fine particles that adhere to equipment. [Means for solving the problem]

[0006] The heat treatment apparatus of this embodiment is a heat treatment apparatus having a treatment chamber, and includes a furnace wall that surrounds the treatment chamber and has a through hole, an apparatus located in the through hole, and an ultrasonic generator that irradiates ultrasonic waves toward the apparatus. [Effects of the Invention]

[0007] According to the heat treatment apparatus of this embodiment, it is possible to reduce the amount of fine particles adhering to the equipment. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an outline of the heat treatment apparatus. [Figure 2] FIG. 2 is a schematic diagram showing an example of the temperature measurement device of FIG. [Figure 3] FIG. 3 is a graph showing the experimental results. [Figure 4] FIG. 4 is a schematic diagram showing an outline of a temperature measuring device in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Summary of Embodiments of the Present Disclosure> The following provides an outline of embodiments of the present disclosure. (1) The heat treatment apparatus of this embodiment is a heat treatment apparatus having a treatment chamber, and includes a furnace wall surrounding the treatment chamber and having a through hole, an apparatus located in the through hole, and an ultrasonic generator that irradiates ultrasonic waves toward the apparatus.

[0010] According to the heat treatment apparatus of this embodiment, even if fine particles are generated in the through-holes of the furnace wall, the fine particles can be agglomerated by ultrasonic waves, thereby reducing the amount of fine particles adhering to the equipment.

[0011] (2) In the heat treatment apparatus described in (1) above, the furnace wall may be made of a material containing carbon.

[0012] By forming the furnace wall from a material containing carbon, the heat resistance of the furnace wall and the through-holes is improved, thereby reducing the risk of equipment deterioration.

[0013] (3) In the heat treatment device described in (1) or (2) above, the ultrasonic generator may include a vibrator and a radiating member connected to the vibrator, and the ultrasonic generator may be positioned so that the direction from the vibrator to the radiating member is parallel to the axial direction of the through hole.

[0014] Since ultrasonic waves are irradiated along the axial direction of the through-hole, the ultrasonic waves intersect with the particles in the through-hole over a wider area than when the ultrasonic waves are irradiated from a direction other than the axial direction, promoting particle aggregation.

[0015] (4) In the heat treatment apparatus described in any one of (1) to (3) above, the equipment includes an electrically conductive member that electrically connects the equipment inside the treatment chamber with the equipment outside the treatment chamber, and the ultrasonic generator irradiates ultrasonic waves around the electrically conductive member.

[0016] The current-carrying member is a metal wire that transmits power or electrical signals and is covered with a protective member. When ultrasonic waves are applied around the current-carrying member, condensation of fine particles is promoted, and adhesion of fine particles to the current-carrying member and the protective member for the current-carrying member is suppressed. As a result, malfunctions such as deterioration, poor insulation, short circuits, leakage, breakage, and poor insulation can be prevented in a high-temperature, particulate-containing environment, and electrical signal transmission and power supply can be performed normally.

[0017] (5) In the heat treatment apparatus described in any one of (1) to (3) above, the equipment may include a temperature sensor, a first protective tube surrounding the temperature sensor, and a second protective tube surrounding the first protective tube, and the ultrasonic generator may irradiate ultrasonic waves toward a cylindrical space formed between the first protective tube and the second protective tube.

[0018] As a result, the temperature sensor is surrounded by the first protective tube, preventing particles from adhering directly to the temperature sensor. Ultrasonic waves are irradiated toward the cylindrical space between the first and second protective tubes, promoting the aggregation of particles in the cylindrical space and suppressing particle adhesion to the temperature sensor. As a result, errors in measurement values ​​due to particle adhesion are reduced.

[0019] (6) In the heat treatment apparatus described in (5) above, the device may have a purge gas supply unit that supplies a purge gas from one side to the other in the axial direction of the cylindrical space.

[0020] As a result, in the cylindrical space between the first and second protective tubes, the particles that have been irradiated with ultrasonic waves and have become larger in particle size are expelled by the purge gas, reducing the amount of particles that adhere to the equipment.

[0021] (7) The heat treatment apparatus according to any one of (1) to (5) above may further include a pressure reducing device communicating with the through hole and the inside of the furnace wall connected to the through hole.

[0022] The pressure reducing device reduces the pressure inside the through hole and the furnace wall connected to the through hole, thereby reducing the pressure around the equipment located in the through hole and suppressing the progression of oxidation of the equipment due to the heat of the heat treatment device.

[0023] (8) The temperature measuring device of this embodiment includes a thermometer having a temperature sensor and a first protective tube surrounding the temperature sensor, a purge gas supply unit for flowing gas along the first protective tube, and an ultrasonic generator, and the ultrasonic generator irradiates ultrasonic waves in a direction along the axial direction of the first protective tube to a gas purged area by the purge gas supply unit.

[0024] According to the temperature measuring device of this embodiment, the particles are agglomerated by ultrasonic waves and the agglomerated particles are discharged by purge gas, so that the amount of particles adhering to the temperature sensor can be reduced and measurement accuracy can be improved.

[0025] (9) In the temperature measuring device described in (8) above, the thermometer may have a second protective tube that surrounds the first protective tube and forms an inner gas purge passage between itself and the first protective tube, and a third protective tube that surrounds the second protective tube and forms an outer gas purge passage between itself and the second protective tube, the second protective tube having a tube wall with a flow path for passing gas, the measurement point of the temperature sensor may be located on the first end side of the temperature sensor, the gas inlet to the inner gas purge passage may be located on the second end side of the temperature sensor, and the gas outlet from the outer gas purge passage may be located on the second end side of the temperature sensor.

[0026] As a result, when the first end of the temperature sensor is positioned outside the furnace wall, the fine particles that have aggregated in the inner gas purge passage can be discharged outside the furnace wall via the inner gas purge passage and the outer gas purge passage.

[0027] (10) In the temperature measuring device described in (8) above, the thermometer may have a second protective tube that surrounds the first protective tube and forms an inner gas purge passage between the first protective tube and the second protective tube, the second protective tube may have a tube wall that has a flow path for passing gas on the first end side of the temperature sensor, and the second end side of the temperature sensor may be a gas inlet to the inner gas purge passage.

[0028] As a result, when it is acceptable to discharge the purge gas toward the processing chamber side rather than the furnace wall, a temperature measuring device without a third protective tube can be used, thereby enabling cost reduction.

[0029] <Embodiment 1> [1. Details of Embodiment 1 of the Present Disclosure] Hereinafter, the first embodiment of the present disclosure will be described in detail with reference to the drawings.

[0030] 1-1. Configuration of Heat Treatment Device 1 is a schematic diagram of a heat treatment apparatus 1 according to an embodiment of the present disclosure. As shown in FIG. 1, the heat treatment apparatus 1 includes a treatment chamber 2, a furnace wall 3, equipment 4, an exterior 5, and a pressure reducing device 9.

[0031] <Processing chamber> The processing chamber 2 has, for example, a rectangular parallelepiped or cylindrical shape. A processing space is formed inside the processing chamber 2. A loading / unloading port 2b may be provided in a wall 2a that separates the inside and outside of the processing chamber 2. The loading / unloading port 2b is an opening for loading and unloading a processing object into and out of the processing chamber.

[0032] The processing chamber 2 performs a predetermined process on the workpiece therein. The predetermined process is, for example, carburizing a metal, high-temperature annealing a semiconductor substrate, or high-temperature firing of a battery electrode substrate. In the case of carburizing, the interior of the processing chamber 2 is filled with a gas containing a large amount of carbon, such as butane or propane. The interior of the processing chamber 2 is heated to a temperature required for the carburizing process and decompressed. In addition, in the case of high-temperature annealing or firing, a non-oxidizing atmosphere is formed inside the processing chamber 2, and the interior is heated to a temperature of 1500°C or higher.

[0033] A material capable of maintaining the processing conditions required for performing a predetermined process is selected for the wall 2a of the processing chamber 2. The material of the wall 2a is a carbon-containing material, such as graphite. A second temperature measuring device 6 is provided in the processing chamber 2. The second temperature measuring device 6 measures the temperature of the processing chamber 2. The second temperature measuring device 6 includes, for example, a thermocouple and a protective tube surrounding the thermocouple.

[0034] <Furnace wall> The furnace wall 3 has a shape that surrounds the processing chamber 2. The processing chamber 2 is located in the space formed inside the furnace wall 3. A heater 7 is provided inside the furnace wall 3. The heater 7 heats the space formed inside the furnace wall 3 and maintains it at a predetermined temperature. The heater 7 is, for example, an electric heater, but is not limited to this. It may also be a heating unit consisting of an induction heating coil that generates a magnetic field and an induction target that generates heat when an induced current flows due to the magnetic field, or it may be a combustion device that burns combustion gas. In addition, a through hole 8 is provided in the furnace wall 3. The equipment 4 is located in the through hole 8.

[0035] The furnace wall 3 also prevents heat from escaping from within the furnace wall 3, keeping the inside of the furnace wall 3 warm. The furnace wall 3 is selected from a material and thickness that has the thermal resistance required to prevent heat from escaping from the interior. The material is also selected with consideration given to not being damaged by the gas present inside the furnace wall 3. The material of the furnace wall 3 is a carbon-containing material, such as graphite. Graphite is stable even at high temperatures, for example, from 850°C to 1050°C. Furthermore, in a non-oxidizing atmosphere, it can withstand temperatures of 2000°C or higher. This improves the heat resistance of the furnace wall 3 and the through holes 8.

[0036] <Exterior> The exterior casing 5 has a shape that covers the furnace wall 3. When a portion of the processing chamber 2 is exposed from the furnace wall 3, the exterior casing 5 covers the exposed portion of the processing chamber 2. The exterior casing 5 protects the furnace wall 3 and processing chamber 2 located inside the exterior casing 5 from external impacts and the like. In addition, the exterior casing 5 prevents an operator from coming into contact with the surface of the furnace wall 3, which may reach a temperature of 100°C or higher. The exterior casing 5 is made of, for example, stainless steel. A first temperature measuring device 4, which will be described later, may be provided on the exterior casing 5.

[0037] <Equipment> The device 4 is a device located in the through hole 8. For example, the device is a first temperature measuring device 4. The first temperature measuring device 4 is inserted into the inside of the furnace wall 3 through the through hole 8. In another example, the device 4 is an electrically conductive member 4. The electrically conductive member 4 electrically connects the devices inside the processing chamber 2 with the devices outside the processing chamber 2. Specifically, the electrically conductive member 4 is a metal wire that transmits power and electrical signals and is covered with a protective material. In this embodiment, the device inside the processing chamber 2 is a heater 7. The device outside the processing chamber 2 is a power supply device (not shown) that supplies power to the heater 7. The electrically conductive member 4 is connected to the heater 7 at one end and to the power supply device at the other end. In yet another example, the device 4 is a rotating shaft for introducing a rotational force into the inside of the furnace wall 3. An agitator provided at the tip of the rotating shaft agitates the gas inside the furnace wall 3. The equipment 4 may have a structure that allows it to be airtightly connected to the exterior 5, for example, so that a decrease in airtightness inside the furnace wall 3 due to the through-hole 8 may be prevented.

[0038] <Temperature measuring device> FIG. 2 is a schematic diagram showing an overview of the first temperature measuring device 4 in FIG. 1. The first temperature measuring device is an example of the equipment 4. The configuration of the first temperature measuring device 4 will be described below. The first temperature measuring device 4 includes a thermometer 20, a second protective tube 22, a third protective tube 23, an ultrasonic generator 24, a purge gas supply unit 29a, a purge gas recovery unit 29b, and a case 25. The first temperature measuring device 4 measures the temperature of the space formed inside the furnace wall 3. A hot spot 27 of the first temperature measuring device 4 is located inside the furnace wall 3.

[0039] <Thermometer> The thermometer 20 includes a temperature sensor 26 and a first protective tube 21 surrounding the temperature sensor 26. The temperature sensor 26 outputs an electrical signal corresponding to the temperature at the measurement point. The temperature sensor 26 is, for example, a thermocouple thermometer. A thermocouple thermometer connects two different metal wires at both ends. When a temperature difference occurs at the junction, a voltage proportional to the temperature difference is generated. This voltage is then measured to measure the temperature. The junction of the thermocouple wires at the measurement point is in thermal contact with the object to be measured. Hereinafter, this junction will be referred to as the temperature measurement junction 27. Therefore, the measurement point of the temperature sensor 26 is the location of the temperature measurement junction 27. The two different metal wires are, for example, a tungsten-rhenium alloy containing 5% rhenium and a tungsten-rhenium alloy containing 26% rhenium. Each metal wire is covered by an insulating tube. The insulating tube may be made of, for example, boron nitride, beryllium oxide, hafnium oxide, zirconia, or alumina.

[0040] The temperature sensor 26 may be a resistance thermometer. A resistance thermometer is a thermometer that measures temperature by measuring the electrical resistance of metals, which changes in electrical resistance with temperature. A resistance thermometer has a structure in which a platinum wire is embedded in an insulator, for example. A protective tube covers the insulator in which the platinum wire is embedded. The protective tube protects the platinum wire from being directly affected by the object being measured.

[0041] The first protective tube 21 surrounds the temperature sensor 26. The first protective tube 21 protects the temperature sensor 26 from contamination and erosion by the object being measured during use. The first protective tube 21 is made of, for example, molybdenum or stainless steel. The first protective tube 21 has a tubular shape that surrounds the temperature sensor 26. The first protective tube 21 has a sealing portion 21a at its first end and an opening 21b at its second end. The first end is the side facing the inside of the furnace wall 3, and the second end is the side facing the outside of the furnace wall 3. The temperature sensor 26 is inserted from the opening 21b at the second end of the first protective tube 21 and is positioned inside the first protective tube 21. The measurement point of the temperature sensor 26 is located at the first end of the first protective tube 21.

[0042] <Second protection tube> The second protective tube 22 surrounds the first protective tube 21. The second protective tube 22 has a tube wall 22a shaped along the axial direction of the temperature sensor 26. A flow path 22c for passing gas is provided at a first end of the tube wall 22a, and an opening 22b is provided at a second end of the tube wall 22a. An inner gas purge passage 28a is formed between the second protective tube 22 and the first protective tube 21. The inner gas purge passage 28a guides purge gas supplied from a purge gas supply unit 29a (described below) from the opening 22b toward the flow path 22c. The purge gas flows out of the flow path 22c. Note that the bold hollow arrow in FIG. 2 indicates the flow direction of the purge gas. The purge gas is an inert gas, such as argon or nitrogen. The second protective tube 22 is made of, for example, stainless steel and molybdenum cladding the stainless steel, and may be further coated with ceramic. The ceramic may be, for example, boron nitride or alumina.

[0043] <3rd protection tube> The third protective pipe 23 surrounds the second protective pipe 22. The first end side of the third protective pipe 23 is closed, and an opening 23b is provided on the second end side. An outer gas purge passage 28b is formed between the third protective pipe 23 and the second protective pipe 22. The outer gas purge passage 28b guides the purge gas flowing out from the flow path 22c to the opening 23b. The material of the third protective pipe 23 is, for example, a material containing carbon (graphite).

[0044] <Purge gas supply unit> The purge gas supply unit 29a supplies purge gas to a cylindrical space formed between the first protective tube 21 and the second protective tube 22, i.e., from one side to the other in the axial direction of the inner gas purge passage 28a. The purge gas supply unit 29a communicates with the first chamber 25a via a purge gas pipe 29c. The purge gas supply unit 29a stores purge gas. The stored purge gas is supplied to the first chamber through the purge gas pipe 29c.

[0045] <Purge gas recovery section> The purge gas recovery unit 29b communicates with the second chamber 25b via a purge gas pipe 29d. The purge gas recovery unit 29b receives the purge gas discharged from the second chamber and recovers the purge gas in, for example, a recovery container.

[0046] <Case> Case 25 has a first chamber 25a and a second chamber 25b inside. First chamber 25a receives purge gas from purge gas supply unit 29a and temporarily stores the purge gas. The purge gas stored in first chamber 25a flows out to inner gas purge passage 28a through opening 22b. Inner gas purge passage 28a guides the purge gas to flow path 22c. Flow path 22c guides the purge gas to outer gas purge passage 28b. Outer gas purge passage 28b guides the purge gas to opening 23b. The purge gas flows into second chamber 25b through opening 23b. The purge gas that has flowed into second chamber 25b is discharged to purge gas recovery unit 29b through purge gas piping 29d.

[0047] <Decompression device> Returning to Fig. 1, the pressure reducing device 9 will be described. The pressure reducing device 9 is in communication with the through hole 8 and the inside of the furnace wall 3 connected to the through hole 8. The pressure reducing device 9 is a vacuum pump such as a rotary pump or a diaphragm pump. The pressure reducing device 9 sucks and exhausts gas inside the through hole 8 and the furnace wall 3 connected to the through hole 8, reducing the pressure below atmospheric pressure.

[0048] As a result, the pressure inside the through hole 8 and the furnace wall 3 connected to the through hole 8 is reduced, and the pressure around the temperature measuring device (equipment) 4 located at the through hole 8 is also reduced. Since the surrounding oxygen is reduced, the progress of oxidation of the temperature measuring device 4 due to the heat of the heat treatment device 1 is suppressed.

[0049] <Ultrasonic generator> Returning to FIG. 2, the ultrasonic generator 24 will be described. The ultrasonic generator 24 radiates ultrasonic waves SS toward the device (temperature measuring device) 4. The ultrasonic generator 24 includes a vibrator 24a and a radiation member 24b connected to the vibrator 24a. The ultrasonic generator 24 is located, for example, closer to the second end than the thermometer 20. The ultrasonic generator 24 is located such that the direction from the vibrator 24a toward the radiation member 24b is parallel to the axial direction of the through-hole 8. The ultrasonic waves are radiated along the axial direction of the through-hole 8. Specifically, the inner gas purge passage 28a of the first temperature measuring device 4 is configured as a long passage extending in a direction parallel to the axial direction of the through-hole 8. The ultrasonic waves are radiated along the axial direction of the inner gas purge passage 28a. Therefore, the ultrasonic waves intersect with the fine particles in the inner gas purge passage 28a over a wider area than when they are radiated from a direction other than the axial direction, promoting particle aggregation.

[0050] The vibrator 24a is a piezoelectric element such as barium titanate or lead zirconate titanate. A piezoelectric element is an element that expands and contracts depending on the direction of an applied electric field. The vibrator 24a generates ultrasonic waves when a predetermined AC voltage is applied. The vibration direction (expansion and contraction direction) of the vibrator 24a is parallel to the axial direction of the through-hole 8. The radiating member 24b receives vibrations from the vibrator 24a and radiates ultrasonic waves in a direction parallel to the axial direction of the through-hole 8.

[0051] The ultrasonic generator 24 irradiates ultrasonic waves toward the cylindrical space formed between the first protective tube 21 and the second protective tube 22. The cylindrical space is the inner gas purge passage 28a. The ultrasonic waves propagate through the inner gas purge passage 28a. The ultrasonic waves propagate through the inner gas purge passage 28a form a standing wave. The length L of the second protective tube 22 may be a length expressed by equation (1). By satisfying equation (1), a standing wave is formed. L=λ / 4×n(n=1, 3, 5,...)...(1) λ: Wavelength of the ultrasonic wave propagating inside the second protective tube 22

[0052] 1-2. Operation of the Heat Treatment Device <When the heat treatment device performs carburizing treatment> An example in which the heat treatment device 1 is a carburizing furnace will be described. First, the treatment chamber 2 is heated to a temperature required for carburizing, for example, 850°C to 1050°C. Next, the workpiece is carried into the treatment chamber 2. The workpiece is an iron product with a low carbon content, such as a bearing component. Then, a carburizing gas containing a large amount of carbon is introduced into the treatment chamber 2. The temperature and carburizing gas of the treatment chamber 2 are maintained, and the workpiece is held in the treatment chamber 2 for a predetermined period. The first temperature measuring device 4 measures the temperature of the space formed inside the furnace wall 3, and the second temperature measuring device 6 measures the temperature inside the treatment chamber 2. Based on the temperatures measured by the first temperature measuring device 4 and the second temperature measuring device 6, the heat treatment apparatus 1 controls the heater 7 to maintain the temperature inside the treatment chamber 2 at a predetermined temperature. After the predetermined period has elapsed, the workpiece is carried out of the treatment chamber 2. The workpiece may then undergo annealing or other processes.

[0053] When the carburizing process is performed as described above, the process chamber 2 is filled with a gas containing a large amount of carbon, and the temperature inside the process chamber 2 rises to, for example, 850°C to 1050°C. Because the furnace wall 3 or the third protective tube 23 is made of carbon, the furnace wall 3 or the third protective tube 23 exposed to high temperatures may generate carbon particles that may adhere to the thermometer 20. Alternatively, carbon particles resulting from the carburizing gas containing a large amount of carbon may enter the first temperature measuring device 4. These carbon particles may adhere to the thermometer 20 and inhibit heat conduction. For this reason, measurements taken by a thermometer 20 with carbon particles attached may contain errors.

[0054] <When the heat treatment device performs high-temperature annealing or high-temperature baking treatment> An example will be described in which the heat treatment apparatus 1 performs high-temperature annealing or high-temperature baking. First, the workpiece is carried into the processing chamber 2. The workpiece is a SiC (Silicon Carbide) wafer, a C (Carbon) wafer, or a battery electrode plate substrate containing a C / C (Carbon / Carbon composite) or graphite. Next, the processing chamber 2 is heated to a temperature required for processing, for example, 1500°C or higher for the wafer and 2000°C or higher for the electrode plate substrate. During the temperature increase, a non-oxidizing atmosphere is formed in the processing chamber 2, which suppresses deterioration of the furnace walls exposed to high temperatures, such as oxidation and reaction with atmospheric gases and pyrolysis products. The non-oxidizing atmosphere is formed by either reducing pressure or introducing an inert gas, or by introducing an inert gas under reduced pressure. The inert gas can be nitrogen gas or a rare gas (helium, neon, argon, krypton, xenon, or radon). The temperature and non-oxidizing atmosphere of the processing chamber 2 are then maintained, and the workpiece is held in the processing chamber 2 for a predetermined period of time. The first temperature measuring device 4 measures the temperature of the space formed inside the furnace wall 3, and the second temperature measuring device 6 measures the temperature inside the processing chamber 2. Based on the temperatures measured by the first temperature measuring device 4 and the second temperature measuring device 6, the heat treatment device 1 controls the heater 7 to maintain the temperature inside the processing chamber 2 at a predetermined temperature. After the predetermined period has elapsed, the workpiece is removed from the processing chamber 2.

[0055] As described above, when high-temperature annealing or baking is performed, the processing chamber 2 is maintained in a non-oxidizing atmosphere, and the temperature inside the processing chamber 2 is raised to a high temperature, for example, 1500°C or higher. Because the furnace wall 3 or the third protective tube 23 is made of carbon, the furnace wall 3 or the third protective tube 23 exposed to high temperatures may generate carbon particles that may adhere to the thermometer 20 or may infiltrate the first temperature measuring device 4. These carbon particles may adhere to the thermometer 20 in a high-temperature environment, impeding heat conduction and potentially degrading the components of the thermometer. For this reason, measurements taken by a thermometer 20 with carbon particles attached may contain errors.

[0056] During the period when heat treatment is being performed by the heat treatment device 1, whether it is a carburizing treatment, a high-temperature annealing treatment, or a high-temperature firing treatment, the purge gas supply unit 29a supplies purge gas to the inner gas purge passage 28a. The purge gas passes through the inner gas purge passage 28a, then through the flow path 22c, the outer gas purge passage 28b, and the second chamber 25b, and is discharged to the purge gas recovery unit 29b. The carbon fine particles are carried along with the flow of the purge gas and are discharged to the purge gas recovery unit 29b.

[0057] However, carbon particles smaller than a predetermined particle size cannot join the flow of the purge gas and remain in the inner gas purge passage 28a, adhering to the thermometer 20. Therefore, there is a risk that the adhering carbon particles will cause a large error in the measurement value.

[0058] Therefore, in an embodiment of the present disclosure, the ultrasonic generator 24 irradiates ultrasonic waves toward the first temperature measuring device 4. The carbon particles that are unable to ride the purge gas flow aggregate due to the irradiated ultrasonic waves, and become larger in particle size than when ultrasonic waves are not irradiated. The carbon particles with larger particle sizes are able to ride the purge gas flow. The carbon particles that are able to ride the purge gas flow are discharged outside the first temperature measuring device 4. This reduces the amount of carbon particles adhering to the thermometer 20, and the thermometer 20 can be maintained in a clean state. As a result, the error in the measurement value is reduced compared to when ultrasonic waves are not irradiated.

[0059] Furthermore, the amount of carbon particles adhering to the thermometer 20 is reduced compared to when ultrasonic waves are not applied, which reduces the risk of the adhering carbon particles reacting with the thermometer 20 and causing a malfunction of the thermometer 20. Malfunctions include, for example, deterioration of the thermocouple wire, poor conductivity, poor insulation, short circuit, and disconnection.

[0060] 1-3. Experiment FIG. 3 is a graph showing the experimental results. In this experiment, the ultrasonic generator 24 first emits ultrasonic waves in step 1 (ultrasound on), then stops the ultrasonic waves in step 2 (ultrasound off), and then emits ultrasonic waves again in step 3 (ultrasound on). The ambient temperature of the experiment is 1550°C. FIG. 3 shows the error of each measurement value in each step. The measurement errors are 0.5°C (step 1), -5.4°C (step 2), and 0.3°C (step 3), respectively. The measurement errors in steps 1 and 3, where ultrasonic waves are irradiated, are reduced compared to step 2, where ultrasonic waves are not irradiated.

[0061] [1-4. Summary] The heat treatment apparatus 1 of this embodiment irradiates ultrasonic waves toward the equipment 4, causing the particles to aggregate and reducing the number of particles adhering to the equipment 4. This reduces errors in the thermometer readings. It also keeps the thermometer clean, reducing the possibility of the thermometer breaking down.

[0062] Even if the furnace wall 3 (through holes 8) contains carbon and carbon fine particles are generated from the furnace wall 3, the first temperature measuring device 4 of this embodiment can discharge the carbon fine particles by purge gas, and further, can aggregate smaller carbon fine particles by ultrasonic waves and discharge them by purge gas. As a result, carbon can be used as the material of the furnace wall 3, and the heat resistance of the furnace wall and the through holes is improved.

[0063] By positioning the ultrasonic generator 24 so that the direction from the vibrator 24a toward the radiation member 24b is parallel to the axial direction of the through-hole 8, ultrasonic waves are irradiated along the axial direction of the through-hole 8. This allows the fine particles in the through-hole 8 to intersect with the ultrasonic waves over a wider area than if the ultrasonic waves were irradiated from a direction other than the axial direction of the through-hole 8, promoting particle aggregation.

[0064] When ultrasonic waves are applied around the current-carrying member 4, the condensation of particles is promoted, and adhesion of particles to the current-carrying member 4 and the protective member for the current-carrying member 4 is suppressed. As a result, in a high-temperature environment containing particles, breakdowns such as deterioration, poor insulation, short circuits, leakage, breakage, and poor insulation can be prevented, and electrical signal transmission and power supply can be performed normally.

[0065] Ultrasonic waves are irradiated toward the space formed between the first protective tube 21 surrounding the temperature sensor 26 and the second protective tube 22 surrounding the first protective tube, which promotes aggregation of the particles and suppresses adhesion of the particles to the temperature sensor. As a result, errors in the thermometer measurement values ​​caused by particle adhesion are reduced, and the risk of thermometer failure (short circuit, breakage, etc. of the thermocouple wire) is reduced.

[0066] The purge gas supply unit 29a of the equipment 4 supplies purge gas from one side of the axial direction of the cylindrical space to the other side, so that the particles that have been irradiated with ultrasound and have increased in size are expelled by the purge gas, thereby suppressing adhesion of the particles to the equipment.

[0067] The pressure reducing device 9 sucks and exhausts the gas inside the through hole 8 and the furnace wall 3 connected to the through hole 8, making the pressure lower than atmospheric pressure, thereby reducing the pressure around the temperature measuring device (equipment) 4 located in the through hole 8. This reduces the amount of oxygen in the surroundings, thereby suppressing the progression of oxidation of the temperature measuring device 4 due to the heat of the heat treatment device 1.

[0068] The temperature measuring device 4 of this embodiment flows purge gas toward the thermometer 20 and irradiates it with ultrasonic waves. This causes the particles to aggregate and be expelled, thereby suppressing adhesion of the particles to the thermometer. As a result, errors in the thermometer measurement values ​​caused by particle adhesion are reduced, and the risk of thermometer failure (deterioration of the thermocouple wire, poor conductivity, poor insulation, short circuit, breakage, etc.) is reduced.

[0069] The thermometer 20 is further provided with a second protective tube 21 that surrounds the thermometer and a third protective tube 23 that surrounds the second protective tube, and the space between the thermometer 20 and the second protective tube 21 communicates with the space between the second protective tube 21 and the third protective tube 23. By flowing a purge gas into this space, the aggregated fine particles can be discharged outside the temperature measuring device 4.

[0070] <Modification> [2. Modification of Heat Treatment Device 1] Hereinafter, modified examples of the heat treatment device 1 of the present disclosure will be described with reference to the drawings. The main difference between the heat treatment apparatus 1 of the modified example and the heat treatment apparatus 1 of embodiment 1 is that the first temperature measurement device 4 of the modified example does not have the third protective tube 23. The same components as those of embodiment 1 are given the same reference numerals, and descriptions of the same components, functions, and operations will be omitted. The overall configuration of the heat treatment apparatus 1 of the modified example is the same as that of embodiment 1, so a diagram showing the overall configuration will be omitted.

[0071] 2-1. Configuration of the temperature measurement device according to the modified example 4 is a schematic diagram of a first temperature measurement device 4 in a modified example. Compared to the heat treatment device 1 of embodiment 1, the first temperature measurement device 4 in the modified example does not have the third protective tube 23. Accordingly, the second chamber 25b is also omitted. [2-2. Operation of the temperature measurement device]

[0072] In this modified example, the first temperature measuring device 4 does not have the third protective tube 23. The purge gas supplied by the purge gas supply unit 29a flows into the inner gas purge passage 28a through the opening 22b. The inner gas purge passage 28a guides the purge gas to the flow path 22c. The purge gas then flows out from the flow path 22c into the space inside the furnace wall 3 (on the first end side).

[0073] If the influence of the outflowing purge gas on the process performed inside the furnace wall 3 (on the first end side) is minor, the third protective tube 23 in the first temperature measuring device 4 may be omitted.

[0074] In this modified example, the first temperature measuring device 4 has a simple structure that does not have the third protective tube 23 or the second chamber. In other words, the number of parts is reduced, which can reduce costs, reduce the frequency of failures, and improve maintainability.

[0075] [2-3. Summary] The first temperature measuring device 4 of the modified example has a simple structure that does not have the third protective pipe 23 and the second chamber, which makes it possible to reduce costs, reduce the frequency of failures, and improve maintainability.

[0076] The embodiments disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is not limited to the above-described embodiments, but includes all modifications within the scope of equivalents to the configurations described in the claims. [Explanation of symbols]

[0077] 1. Heat treatment equipment 2. Processing chamber 2a wall 2b Loading / unloading exit 3 Furnace wall 4. Equipment (first temperature measuring device, current-carrying member) 5. Exterior 6 Second temperature measuring device 7 Heater 9. Pressure reducing device 8 through holes 20 thermometer 21 1st protection tube 21a Sealing part 21b opening 22 2nd protection tube 22a Tube wall 22b opening 22c Channel 23 Third protection tube 23b opening 24 Ultrasonic generator 24a vibrator 24b Radiating member 25 cases 25a Room 1 25b Room 2 26 Temperature sensor (thermocouple wire) 27 Temperature measuring junction 28a Inner gas purge passage 28b outer gas purge passage 29a Purge gas supply unit 29b Purge gas recovery section 29c Purge gas piping 29d Purge gas piping

Claims

1. A heat treatment apparatus having a treatment chamber, a furnace wall surrounding the processing chamber and having a through hole; An instrument located in the through hole; an ultrasonic generator that emits ultrasonic waves toward the device; A heat treatment device comprising:

2. The furnace wall is made of a material containing carbon. The heat treatment apparatus according to claim 1 .

3. The ultrasonic generator comprises: a transducer and a radiating member connected to the transducer; The ultrasonic generator is positioned so that the direction from the transducer toward the radiating member is parallel to the axial direction of the through hole. The heat treatment apparatus according to claim 1 .

4. the device includes a current-carrying member that electrically connects the device inside the processing chamber with the device outside the processing chamber, The ultrasonic generator irradiates ultrasonic waves around the current-carrying member. The heat treatment apparatus according to any one of claims 1 to 3.

5. the device includes a temperature sensor, a first protective tube surrounding the temperature sensor, and a second protective tube surrounding the first protective tube; the ultrasonic generator irradiates ultrasonic waves toward a cylindrical space formed between the first protective tube and the second protective tube. The heat treatment apparatus according to any one of claims 1 to 3.

6. The device further includes a purge gas supply unit that supplies a purge gas from one side to the other side in the axial direction of the cylindrical space. The heat treatment apparatus according to claim 5 .

7. The heat treatment apparatus according to claim 1 , further comprising a pressure reducing device communicating with the through hole and the inside of the furnace wall connected to the through hole.

8. a thermometer having a temperature sensor and a first protective tube surrounding the temperature sensor; a purge gas supply unit for flowing gas along the first protective tube; an ultrasonic generator; the ultrasonic generator irradiates an ultrasonic wave to a gas purge region by the purge gas supply unit in a direction along an axial direction of the first protective tube. Temperature measuring device.

9. The thermometer is a second protective tube surrounding the first protective tube and defining an inner gas purge passage between the first protective tube and the second protective tube; a third protective tube surrounding the second protective tube and defining an outer gas purge passage between the third protective tube and the second protective tube, the second protective tube has a tube wall provided with a flow path for passing gas; a measurement point of the temperature sensor is located on a first end side of the temperature sensor; a gas inlet to the inner gas purge passage is located on a second end side of the temperature sensor; a gas outlet from the outer gas purge passage located on the second end side of the temperature sensor; 9. The temperature measurement device according to claim 8.

10. The thermometer is a second protective tube surrounding the first protective tube and forming an inner gas purge passage between the first protective tube and the second protective tube; the second protective tube has a tube wall provided with a flow path for passing gas; a second end side of the temperature sensor is an inlet for gas to the inner gas purge passage; 9. The temperature measurement device according to claim 8.

Images