JPH058476Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a temperature detection device for a hot isostatic pressurizing device that detects a difference in the amount of expansion and contraction due to thermal expansion and converts the detected displacement signal into a temperature signal. (Prior Art) Each process in the industrial field involves many temperature measurements, and the detected temperature information is utilized for control and monitoring, so it is desirable that the temperature information has high reliability. Among these, the demand for this is particularly high in fields such as hot isostatic pressurization equipment where objects to be processed are placed in a high temperature and high pressure atmosphere. Accurate temperature control is necessary to obtain products of excellent quality using the hot isostatic pressurization device, and such accurate temperature control is only possible if a reliable temperature detection means is established. Nothing else but to become. However, thermocouples have traditionally been widely used due to their simplicity, and recently, temperature detection methods using optical fibers have been developed.
Since these are used in practical use, these will be taken as examples and explained below. (B) Prior Art 1 As is well known, in a thermocouple, one end of each strand of different types of wires is joined to form a hot junction, and each strand except for the hot junction Insulate the parts so that they do not short-circuit each other, and insert them into the protective tube.
The thermal contact portion is fixed at a target temperature detection position within the processing chamber. Therefore, when the thermal contact portion detects the temperature, a thermoelectromotive force corresponding to the detected temperature is generated in the thermal contact portion. The thermoelectromotive force is led out of the high-pressure container through a lead wire or the like, and is converted into a quantity corresponding to the detected temperature.
For thermocouple wire, for example, Pt-Pt 13%
Rh (JIS R line), CA line (JIS K line), W/5%Re
-W・26%Re etc. (B) Prior Art 2 In recent years, there have been many proposals regarding temperature detection devices or methods using optical fibers. Generally, a temperature detection device using the optical fiber is composed of three parts: a head part, an optical fiber, and a detection part. The head section has a function of condensing radiant energy from the object to be temperature measured by optical means and making the collected radiant energy enter the surface of the optical fiber facing the object to be temperature measured. do. The optical fiber also serves to transmit the radiant energy to the detection section connected to the opposite side of the optical fiber, and the detection section typically includes a detector that converts the light into electrical output. , an amplifier that amplifies the value detected by the detector, and a linearizer that converts the detected value into a temperature output. Therefore, when radiant energy is incident from the opposing surface of the optical fiber through the head portion, the radiant energy is transmitted to the detector while being reflected between the outer circumferential inner side of the optical fiber. The detector converts the radiant energy into a corresponding electrical output.
Since the electrical output is weak, the temperature is detected by amplifying it by the amplifier and converting it into a temperature value corresponding to the temperature of the object to be measured by the linearizer. It is a temperature detection device. The configuration of the optical fiber includes a single optical fiber and a bundle of multiple optical fibers. (Problems to be Solved by the Invention) Thermocouples have been widely used since the beginning, and it is well known that temperature detection devices using optical fibers have also tended to be frequently used in recent years. However, in recent years, the use of an inert gas such as argon or nitrogen as a pressure medium has been increasing, and high temperature and high pressure are simultaneously applied to the object housed in the processing chamber. The method described below is not yet suitable for use in detecting the temperature inside the processing chamber of a hot isostatic pressing apparatus that performs various processes such as sintering, removing defects in cast products, and manufacturing composite materials by high-pressure impregnation. There are drawbacks. That is, the thermocouple explained in the section of Prior Art 1 is
Its lifespan is extremely short under high temperature and high pressure conditions, and the thermoelectromotive force deteriorates significantly over time. For example, it is said that under high temperature and high pressure conditions of 2000° C. and 1000 atm, thermoelectromotive force deterioration occurs by approximately 1% per hour. Hot isostatic pressurization equipment uses inert gas as the pressure medium, but thermocouples are easily affected by it under high temperature and high pressure conditions, causing material changes such as coarsening of crystal grains. cannot be avoided. Further, in the temperature detection device using an optical fiber described in Prior Art 2, the temperature of the object to be measured is detected by the radiant energy incident on the end face of the optical fiber. The radiant energy emitted increases as the temperature rises, but as is well known, it is very weak when the temperature of the object to be measured is low. Therefore, in order to measure from low to high temperatures, it is necessary to select a wavelength, but there is no wavelength that covers everything from room temperature to about 2000°C, for example. Therefore, it is conceivable to separate the wavelength for measuring the low temperature range and the wavelength for measuring the high temperature range, but this would also increase the cost. That is, in practice, the temperature rise in the low temperature range is not monitored, and only the temperature in the high temperature range is detected by a temperature detection device using an optical fiber. However, in order to process objects with a hot isostatic pressurization device and obtain products of excellent quality, it is necessary to know the temperature value, as it is necessary to control the temperature rise even in the low temperature range. .
Therefore, it is necessary to employ a two-stage temperature detection means, such as using a thermocouple to detect the temperature in the low temperature range and using an optical fiber to detect the temperature in the high temperature range, which is wasteful. In addition, since the radiant energy input part of the optical fiber and a part thereof are placed under high pressure, the optical fiber is pushed and deformed by the high pressure, and its refractive index changes, and as the pressure increases, There is also the problem that temperature detection accuracy decreases. Therefore, the present invention has developed a hot isostatic pressure device that can detect temperatures ranging from low to high temperatures in a stable state, and can also detect temperatures with the same accuracy regardless of the pressure. The purpose is to provide a detection device. (Means for Solving the Problems) The present invention provides a structure in which a lower sealing lid is loosely fitted into the upper part of the support tube 5 installed in an upright manner inside the support tube 5, and the lower part of the support tube 5 is opened at the lower end of the support tube 5. The upper part protruding from the lower sealing lid to the lower sealing lid is made of a different material from the support tube 5 and has a different coefficient of linear expansion, and the lower part supports the detection rod 6 made of the same material as the support tube 5. We have attempted to solve the problems of the conventional technology explained in the previous section, and therefore, its features include a high-pressure vessel 1 sealed with a lower sealing lid, and a structure disposed inside the high-pressure vessel 1. A heat insulating layer 2 provided, a heater 3 provided inside the heat insulating layer 2, and a heater 3
In a hot isostatic pressurizing apparatus comprising a processing chamber 4 defined inside the processing chamber 4, a temperature detection device for detecting the temperature inside the processing chamber 4 is installed upright on a lower sealing lid and has a heat-resistant, open bottom end. The support tube 5 is supported by the upper part of the support tube 5, and the lower part of the support tube 5 is loosely fitted inside the support tube 5 and protrudes from the lower opening into the lower sealing lid, and is in line with the support tube 5. A protruding rod 6 consisting of an upper part made of different materials with different expansion coefficients and a lower part made of the same material as the support tube 5 is disposed within the lower sealing lid at a corresponding position of the lower protrusion of the detection rod 6. The configuration includes a displacement detecting means 7 for detecting the amount of displacement of the protrusion, and a converting means 8 disposed outside the high-pressure container 1 and converting the displacement signal detected by the displacement detecting means 7 into a temperature signal. It's right there. (Function) When the temperature in the processing chamber 4 starts to rise by the heater 3, the support tube 5 with the lower sealed lid erected and the detection rod 6 supported on the upper part of the support tube 5 both start to rise. , their temperature increases corresponding to the temperature inside the processing chamber 4 and expands. However, the present invention
Since the lower portions of the support tube 5 and the detection rod 6 are made of the same material, the amount of expansion of the lower portions of the support tube 5 and the detection rod 6 made of the same material in the processing chamber 4 is canceled out, and the expansion amount is mainly The lower protruding portion of the detection rod 6 is displaced due to the difference in expansion based on the linear expansion of the support tube 5 of the rod 6 and the upper portion of the upper portion made of different materials having different coefficients of linear expansion. Therefore, the displacement is detected by the displacement detection means 7 disposed in the lower sealing lid at a position corresponding to the protrusion of the detection rod 6, and furthermore, the displacement signal detected by the displacement detection means 7 is transmitted to the high pressure vessel. 1, the detection rod 6 is
The temperature signal is converted into a temperature signal corresponding to the average temperature in the vertical direction of the support tube 5 and the upper portion made of different materials. The coefficient of linear expansion corresponding to the temperature of the support tube 5 and the detection rod 6 is reproducible and stable, and does not change even when hydrostatic pressure is applied. That is, temperature can be detected in a stable state from a low temperature range to a high temperature range, and the temperature detection accuracy is less likely to change depending on the level of pressure. (Example) This example will be described below with reference to FIGS. 1 to 6. First Example A first example will be described below based on FIGS. 1 to 5. Reference numeral 1 shown in FIG. 1 is a high-pressure container whose upper and lower openings are sealed.
Inside is a crested insulation layer 2 whose upper part is sealed.
will be placed. The heat insulating layer 2 is provided inside the heat insulating layer 2.
A heater 3 is arranged concentrically with the vertical axis of the heater 3, and a processing chamber 4 for accommodating the object to be processed is defined inside the heater 3. The upper end of the heater 3 is sealed at a position facing the radial center of the processing chamber 4 at 180 degrees and close to the heater 3, and approximately parallel to the vertical direction of the heater 3. The lower part of the heat-resistant support tube 5, which is open at the lower part, is supported on the upper surface of the lower sealing lid of the high-pressure vessel 1. A detection rod 6 whose lower part fits loosely inside the support tube 5 is fixed to the sealed lower surface of the support tube 5 . The detection rod 6 has an upper part made of a different material having a different coefficient of linear expansion than the support tube 5, and a lower part made of the same material as the support tube 5. The detection rod 6
The lower end protrudes from the lower opening of the support tube 5 and is loosely fitted into a recess formed in the lower sealing lid below the support tube 5. The method of fixing both parts of the detection rod 6 is simple if a screw-in method or a pin connection method is adopted as shown in FIG. 4A and B. Note that these fixing methods have already been proposed in Application No. 169991. The lower protrusion of the detection rod 6 is loosely fitted into the recess formed in the lower sealing lid, and the outer circumference of the detection rod 6 is
A differential transformer 7 having two coils 9 wound therein is disposed, and both ends of each of the coils 9 are led out from the recess of the lower sealing lid through a perforated hole leading outward to the outside of the high-pressure vessel 1. The configuration is such that it is connected to the arranged temperature converter 8 and a power source. Therefore, the detection rod 6 expands in response to the temperature inside the processing chamber 4, and the amount of linear expansion of the upper portion of the detection rod 6 is transmitted to the lower portion thereof. The support tube 5
Both the support tube 5 and the detection rod 6 expand in response to the temperature in the processing chamber 4, but since the lower portions of the support tube 5 and the detection rod 6 are made of the same material, the support tube 5 and the detection rod 6 expand.
The amount of expansion of the lower portion is canceled out, and the lower position of the lower portion of the detection rod 6 is displaced based on the amount of expansion in the vertical direction of the upper portion of the detection rod 6. On the other hand, a coil 9 wound around the center of the differential transformer 7 is energized from the power source. Therefore, the detection rod 6
An induced voltage difference corresponding to the lower displacement of is generated between the coils 9 on both ends of the differential transformer 7, and the induced voltage difference is converted into a temperature signal by the temperature converter 8. The vertical length of the upper portion of the detection rod 6, which is made of a different material having a different coefficient of linear expansion from that of the support tube 5, is important. In other words, the length of the detection rod 6 is determined so that it can be used even in the temperature range to be detected and at low temperatures that require temperature control or monitoring within the processing chamber 4.
It is determined by the ability to displace the lower part of the . In addition, the support tube 5 and the detection rod 6 are each required to have high heat resistance and high stability against the atmosphere.
It is desirable that the difference in linear expansion coefficient between the lower part of the support tube 5 and the detection rod 6 and the upper part of the detection rod 6 be large in order to improve temperature detection accuracy. Various types of refractories have been developed and are used according to their properties. Examples can be given. In addition, the numerical value written in parentheses shows the linear expansion coefficient of each refractory in the temperature range of 300°C to 400°C.

【table】

[Table] In this embodiment, in order to detect the displacement of the lower part of the detection rod 6, a differential transformer 7 is used to convert the displacement into an induced electromotive force. As shown in , two protrusions projecting perpendicularly to the longitudinal direction are provided at the lower end of the detection rod 6 in the vertical direction, and a metal plate 10 is provided between the two protrusions.
The metal plate 10 is clamped in the thickness direction of the detection rod 6 and is fixed in a flexible manner perpendicular to the longitudinal direction of the detection rod 6 at a position away from the clamping part, and is located between the clamping part and the clamping part. Paste the strain gauge 11 on the surface,
The bending distortion of the metal plate 10 caused by the displacement of the lower end of the detection rod 6 may be detected. Further, if the lower end of the detection rod 6 is displaced downward than the surface of the metal plate 10 in an unloaded state due to a rise in temperature, the two protrusions are unnecessary and the lower end of the detection rod 6 is It is only necessary to keep it in contact with the upper surface of the metal plate 10. Second Embodiment The second embodiment will be described below with reference to FIG. 6, with only the differences from the first embodiment. That is, the support tube 5, which is open at both ends, avoids the processing object accommodated in the processing chamber 4.
It is supported by the upper surface of the lower sealing lid of the lower high pressure container 1. An upper portion of a detection rod 6 having an outer diameter approximately equal to the outer diameter of the support tube 5 and having a through hole in the center in the radial direction is fixed to the upper end surface of the support tube 6. The lower side of the through hole loosely fits inside the support tube 5, and the upper part of the lower side of the detection rod 6 protruding from the lower opening of the support tube 5 has a gap with the inside of the through hole. The upper part is inserted through the upper part and fixed at an upper position of the upper part. That is, in this embodiment, when the upper part of the detection rod 6 expands, it extends upward, and the only difference from the first embodiment is the direction of displacement of the lower end of the detection rod 6. be. Therefore,
Its action and effect are the same as those of the first embodiment. Further, as the displacement detection means 7 for detecting the displacement of the lower end portion of the detection rod 6, any of the displacement detection means 72 described in the first embodiment can be applied. (Effect of the invention) The present invention has a lower part loosely fitted into the upper part of the support tube 5 installed in the lower sealing lid inside the support tube 5,
A detection rod 6 protrudes from the lower opening of the support tube 5 into the lower sealing lid, and has an upper portion made of a different material having a different coefficient of linear expansion than the support tube 5, and a lower portion made of the same material as the support tube 5. The configuration supports the following. Therefore, when the temperature in the processing chamber 4 is raised by the heater 3, both the support tube 5 and the detection rod 6 expand in their respective longitudinal directions due to linear expansion. 5 and the linear expansion of the lower part of the detection rod 6 made of the same material cancel each other out, and the support tube 5 of the detection rod 6
The lower end side of the detection rod 6 is displaced based on the difference in the amount of linear expansion of the upper portion made of different materials with different coefficients of linear expansion. The linear expansion coefficient of the upper part of the detection rod 6, which is a heat-resistant material, is determined by a few exceptional materials, such as silicon oxide,
Except for zirconium oxide, etc., it is approximately constant, or increases proportionally as the temperature rises, and is stable regardless of temperature, and has good reproducibility. Therefore, it has become possible to continue detecting the temperature inside the processing chamber 4 in a stable state from a low temperature range to a high temperature range. Furthermore, since the linear expansion coefficients of the support tube 5 and the detection rod 6 are stable and do not change even under high pressure, the temperature can be detected with the same degree of accuracy even if the pressure inside the processing chamber changes. be able to. Since the displacement detection means 7 is disposed within the lower sealing lid in the low temperature region, the amount of displacement can also be detected stably. Therefore, the present invention can be used more stably than thermocouples, and can only be used in high temperature ranges, such as temperature detection using optical fibers, or
We were able to realize an extremely excellent and useful temperature detection device for a hot isostatic pressurization device that utilizes linear expansion difference, in which the temperature detection accuracy does not change due to pressure changes within the processing chamber.

[Brief explanation of drawings]

FIG. 1 is a front sectional view showing the first embodiment, FIG. 2 is a sectional view taken along line A-A in FIG. is a front cross-sectional view showing an example of fixation between the detection rod and the support tube, FIG. 5 is a side view of the displacement detection device using a strain gauge, and FIG.
FIG. 2 is a front cross-sectional view of the main parts of the temperature detection device according to the embodiment. DESCRIPTION OF SYMBOLS 1... High pressure container, 2... Heat insulation layer, 3... Heater, 4... Processing chamber, 5... Support tube, 6... Detection rod, 7... Differential transformer, 8... Temperature converter, 9
...Coil, 10...Metal plate, 11...Strain gauge.

Claims (1)

[Scope of utility model registration request] A high-pressure vessel 1 sealed with a lower sealing lid, a heat insulating material 2 disposed inside the high-pressure vessel 1, a heater 3 disposed inside the heat insulating material 2, and a screen formed inside the heater 3. In the hot isostatic pressurizing apparatus, the temperature detection device for detecting the temperature inside the processing chamber 4 is a heat-resistant support tube with a lower sealed lid and an open bottom end. 5, which is supported by the upper part of the support tube 5, whose lower part fits loosely inside the support tube 5 and protrudes from the lower opening into the lower sealing lid, and which has a linear expansion coefficient different from that of the support tube 5. A detection rod 6 consisting of an upper part made of a different material and a lower part made of the same material as the support tube 5 is arranged in a lower sealing lid at a position corresponding to a lower protrusion of the detection rod 6, and is arranged in a lower sealing lid at a position corresponding to a lower protrusion of the detection rod 6, and is arranged in a lower sealing lid at a position corresponding to a lower protrusion of the detection rod 6. displacement detection means 7 for detecting the amount, and the high pressure container 1
A temperature detection device for a hot isostatic pressurizing device, characterized in that it includes a conversion device 8 disposed outside of the displacement detection device 7 for converting a displacement signal detected by the displacement detection device 7 into a temperature signal.