JPS60218583A - Measuring device for temperature in high-temperature high-pressure furnace - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention relates to a pressure sintering furnace, a hot isostatic pressing apparatus (hereinafter referred to as
Under a pressurized gas atmosphere, such as a HIP device, 20
4 high-temperature measuring devices used at temperatures near 00°C;
In particular, it relates to the structure of a thermocouple for high temperature measurement.

(b) Conventional technology In recent years, non-oxide ceramics such as silicon nitride (5i3N4) and silicon carbide (5in) have attracted attention as high-strength components used in high-efficiency gas turbines or diesel engines, and active research and development investment has been made. For example, Si3N is used as a means for the manufacturing process.

In N2 atmosphere, temperature 1800-2100℃, pressure 10
The use of a pressure sintering furnace of ~100"ly/l and a H-P apparatus with a N2 atmosphere, a temperature of 1700 to 1800°C, and a pressure of 1000 to 2000 Kg is being considered.

By the way, as a means of measuring the internal temperature of these pressure sintering furnaces or H-P devices, it is preferable to use optical temperature measuring means such as a radiation thermometer since they are used in high temperature ranges exceeding 1700°C. In this method, it is necessary to directly guide the emitted light from the furnace chamber to the sensor section, so for example,
In the HIP device shown in the figure, the top! (21), lower lid (2
It is necessary to provide apertures (2η (281) in the pressure vessel equipped with a pressure vessel (2)) and a heat insulating layer (281) for thermal insulation between the inner wall of the pressure vessel and the furnace chamber (23).

However, in this case, the opening (2) causes a decrease in the strength of the pressure vessel (goods), and the opening (3) also causes heat loss due to the circulation of the internal pressure gas, so optical temperature measurement means are not used. is virtually impossible to apply, and even in a pressure sintering furnace, at best,
Only about 9 out of 10 people are seen applying it to Io1.

Therefore, the so-called High Pressure Gas Control Law applies: c.
Currently available W-Re thermocouples (
For example, manufactured by HO3KIIs in the United States, φ0.5. The only option left is to apply the W-Re Otsuju thermocouple.

Therefore, in the HIF device, etc., the above-mentioned commercially available thermocouple is inserted into the insulated tube, held at the upper end of the insulated tube, and the thermocouple is inserted into the protective tube with the tip closed. Attempts have been made to house it inside the heat insulating layer inside the pressure vessel, and have devised ways to attach it.

However, the above-mentioned commercially available W-Re thermocouples usually have a wire diameter of about 0.5 a, which is about 20 mm.
When applied to a H-P device with a diameter of 2 oomm and a length of 500 pieces with a temperature range of 00°C, the above thermocouple is semi-restricted at both the upper and lower ends, so it exhibits a bowed state due to thermal expansion, and eventually Its lifespan is barely enough to withstand one operation, which is a major hindrance to the use of high-temperature, high-pressure furnaces such as the 2000°C specification H-P equipment for industrial production.

(c) Problems to be Solved by the Invention: The present invention addresses the above-mentioned actual situation, prevents a decrease in the life of W-Re thermocouples, and prevents damage caused by thermal expansion. The purpose of this study is to improve the efficiency of high-pressure furnace temperature measurement means and eliminate obstacles to its industrial production, and to solve these problems by focusing on the wire diameter, which is a component of thermocouples, and its support mode. It is something.

B) Means for Solving the ProblemsThe present invention, which is suitable for the above purpose, is characterized by housing an insulating tube with an insertion hole in the protective tube, and inserting the entire thermocouple wire into the insulating tube. In the temperature measuring device for the high-temperature and high-pressure furnace, the thermocouple wire is held vertically downward at the upper end of the insulated tube, and the thermocouple wire is formed into large-diameter positive and negative side rod members, and each of the insulated tubes is The corresponding thermocouple rod member insertion hole is made larger in diameter than the diameter of each rod portion 4'A, and there is a gap 'mf between each rod member and each rod member insertion hole of the insulating tube at least in the high temperature region: The point is that each rod member is suspended concentrically within the insertion hole of the insulating tube in a substantially non-contact state.

Here, the thermocouple is usually made of W or/and W-Re based material, and the insulating tube is usually made of BN material.

The rod member, which constitutes the main part of the thermocouple, has a much larger diameter and is much more rigid than the conventional thermocouple wire, and has a diameter of 3 or more on both the plus side and the minus side.

Both of these rond members are threaded at both ends, and are configured as a thermocouple by being screwed into a rod member fastening button, or by being joined by a tight fit, other mechanical means, or welding.

In this case, the material of the rod member fastening button may be any of the materials that constitute the positive side and the negative side of the thermocouple rod member, but from the viewpoint of thread processing and strength, a material on the negative side that has more ductility is used. That's a good thing.

However, of course, it is clear that the thermocouple can be configured using materials other than those on the positive side and negative side, and there is no problem even if a material with a composition intermediate between the two is used.

In addition, in order to strengthen the screw connection between the rod member and the fastening button, a retightening nut may be used. In this case, the positive side of the nut is made of positive material, and the negative side is made of negative material. It is preferable to manufacture it from a material to prevent loosening due to differences in thermal expansion coefficients of the materials and to stably generate thermoelectromotive force.

Each of the thermocouples having the above configuration is attached to an insulating tube having two insertion holes into which the positive side and negative side 971 members are inserted, and each rod member is inserted into the insertion hole from the upper end of the insulating tube. Although this insulating tube, which is held suspended vertically downward, can be composed of a single long tube, it is preferable to use multiple short tubes so that it can be adjusted to any desired length. It is preferable to stack the tubes in multiple stages, and normally, such multi-stage stacked insulating tubes are used.

In this case, it is necessary to ensure that each of the short tubes is arranged concentrically.5. Therefore, it is preferable to provide two through holes in addition to the rod member insertion hole, and to pass the entire rod through the through holes over the entire axial length so that the rod member insertion hole is concentric in the axial direction over the entire length. be. The rod material used at this time is W or/and W, similar to the rod member of the thermocouple, considering the resistance at 2000°C.
- It is desirable to use a Re-based material.

Furthermore, in addition to the above, in addition to the concentric arrangement of the insertion holes, the electromotive force characteristics of the thermocouple were tested using a commercially available passion couple, such as the American HO5KI.
The insulating tube may be constructed so as to be able to be verified by the NS product.

In addition, the material for the above-mentioned insulating tube is as described above (B
Although it is preferable to use Ni, it is also possible to use AL203 below the thermocouple unit in an area where the temperature is below 1800'C.

Thus, at its upper end during the insulating tube! 'A thermocouple unit for high temperature measurement according to the present invention, which is the ultimate objective of installing a thermocouple including a thermocouple rod member held vertically in a furnace chamber by covering it with a protective tube with one end closed. is configured.

In this case, the material of the protection tube is 20
B from the viewpoint of resistance at 00℃ level, workability and cost.
N is preferably used.

Note that the thermocouple unit configured as described above is used in a high-temperature, high-pressure furnace, and at this time, from the upper end of the sample installation table that serves as a heat insulator in the lower part of the furnace chamber of the H-P equipment. By making the thermocouple rod member insertion hole of at least one insulating tube located in the lower region approximately the same diameter as the thermocouple rod member, the contact between the rigid thermocouple rond and the insulating tube is maintained in the high-temperature furnace chamber. In this region, only the upper end of the insulating tube is present, which is suitable for avoiding shunt errors due to deterioration of electrical insulation properties of the insulating tube material at high temperatures.

However, no matter what, the thermocouple rod member is held suspended at the upper end of the insulating tube via the button for fastening the thermocouple rod member, so there is no chance of contact between the thermocouple rod member and the insulating tube. Therefore, it goes without saying that the same effect can be achieved even if the upper end insertion hole of the uppermost insulating tube has a smaller diameter. Contact is preferable.

In most other places, contact has not occurred,
In this sense, it can be said that there is almost no contact.

Furthermore, if the thermocouple rod member and the insulating tube come into contact at high temperatures, EN decomposes and B diffuses into the thermocouple rod member, causing a decrease in thermoelectromotive force in the long run. As a means for improving this, it is preferable to interpose a spacer made of a different material from the insulating tube, for example, having two holes, between the top of the insulating tube and the fastening button. This spacer is easy to work with because its amount is small.

Since costs can be relatively ignored and materials can be selected with the highest priority on performance, for example, beds that have excellent electrical insulation but have toxicity issues, and T-shirts that have radioactivity issues.
h, Q2. Other expensive HfO2, Y2
The use of O3 is also possible.

Note that the configuration in which the thermocouple rod member and the BN insulating tube are maintained in non-contact in most of the high temperature range is preferable not only from the viewpoint of the occurrence of the shunt error but also from the viewpoint of improving the temperature measurement accuracy described above. Needless to say.

(e) Examples Hereinafter, the present invention will be explained in detail based on the accompanying drawings.

FIG. 1 shows an example of a thermocouple unit that constitutes the main part of the device of the present invention, where (T) is a thermocouple unit, (1) is a thermocouple configured with a screw fastening structure, and (2) is a thermocouple. The positive side rod member (3) is also the negative side rod member of the thermocouple, and both of these parts +J (2) and (3) are threaded at both ends, as shown in Figure 1 (b). Rod member insertion hole (+a) (Insulating tube (11) with 135
It is inserted into the inside of the insertion hole α3) (13) and the
The upper threaded part is screwed into a fastening button (4) which has two female threads machined at the upper end of the pipe (11) to screw the rod members (2) and (3), and an additional screw part is added to make the screw connection even stronger. The thermocouple (1) is tightened with (5) and (6) and held suspended vertically from the upper end of the insulating tube 0υ in which short tube bodies as shown in Fig. 2 are stacked in multiple stages. (5) The lower end of the rond part protruding downward is also made of the same material and shape as (6) (7) The temperature recorder (not shown in the figure) It is connected to a lead wire (9) α0) that facilitates connection to Then, the thermocouple (
]) is covered and protected by a protective tube (I2).

In the above configuration, the rod members (2) and (3) are made of a material such that the positive side rod member is made of W and W-Re thread materials, such as W-3%Re, W-5%Re, etc. (3) corresponds to W and W-5%Re of the positive side material, W-26%Re, W-
W-25%Rθ materials are used in response to 3% Re, and the Rondo diameter is used to ensure rigidity, facilitate thread processing, especially female thread processing for mating, and improve expected life when applied to industrial equipment. From this point of view, it is more than 3 years old.

Further, the fastening button (4) into which the rond member is screwed has two internal threads as shown in FIG. It is made of a material with an intermediate composition between the two, and the positive side is the material of the positive rod member (2), and the negative side is the material of the negative rod member (3). Furthermore, lead wires (9) (10) made of the same material are used to facilitate connection from the large diameter Rondo members (2) (3) to a temperature recorder, etc.
), for example, a commercially available 0.5φ manufactured by HOSKINS.
A compensation conductor for W-Re is used.

Note that the insulating tube (11) is connected to the rod member (2) (3).
The insertion hole diameter is larger than that of the conventional tube, and it is constructed by stacking short tubes in multiple stages as shown in FIG. 1(A) and FIG. It is important that the rod member insertion holes (1a) and (ta) are stacked concentrically in the axial direction.

As the material of the insulating tube, BN is used at the 2000°C level, but A403e can also be used at the temperature below 1800°C.

3 to 5 show examples of configurations for easily securing such concentric arrangement, and in FIG. 3, the rod member insertion hole α3) (in addition to the rod member insertion hole α3) θ→α5) is provided, and the rod member (2) (3) of the thermocouple is inserted into this through hole 04) (15) over the entire length in the axial direction.
Similarly, a bar made of W or/and W-Re based material is passed through. On the other hand, in FIGS. 4 and 5, the entire insulating tube α1) is configured so that the rod member insertion hole α is arranged concentrically and can be tested using a commercially available test pair.

That is, in the figure, (17) and (18) are the insertion holes for the certified thermocouple wires, and (19) is the counterbore provided in the uppermost insulating tube for the tip of the certified thermocouple (T'l). is stored.

FIG. 6 shows another embodiment of the thermocouple according to the present invention. Its basic structure is the same as that described above, and the same parts are indicated by the same reference numerals.
11) At the top of the insulating tube 0 between the fastening button (4)
A spacer (10)ff made of a different material than 1) and having two holes, for example, is inserted to prevent a long-term drop in thermoelectromotive force under high temperatures due to contact between the thermocouple and the insulating tube, and to prevent temperature measurement. This greatly improves accuracy.

The configuration of the thermal lightning pair unit, which constitutes the main part of the present invention, is as described above. When installing this unit in a high-temperature and high-pressure furnace, for example, in the HIP apparatus shown in FIG.
The inner heating device (26) is mounted inside by a support member.

At this time, the rod member (2) <3) is the insulating tube (11)
The upper end of the rod member insertion hole α3) oa) is supported and suspended, but since the diameter of the insertion hole (the facing plow is larger than that of the rod members (2) and (8)) There is a gap between them, and in the case of the thermocouple shown in Figure 1, the thermocouple rod members (2) (3) and the insulating tube (U) only come into contact at the upper point (B), and almost no other contact occurs. Contact does not occur most of the time, and the non-contact state is maintained (see the upper part of Figure 7 (b)). The thermocouple rod member (2) should have approximately the same diameter as the member (3) (see the lower part of Figure 7 (b)).
3) and the insulating tube α1) (lla) because the thermocouple rod member insertion holes (13) (135) are concentric, the only contact in the high-temperature furnace chamber area is at the point (B) in Figure 1. Shunt errors due to poor electrical insulation underneath can be avoided.

In addition, the temperature range in which the insulating tube (lla) having the small-diameter insertion holes (13a) (13s: ) is arranged is W-R.
In the combination of an e-type thermocouple and a BN insulated tube, the electrical insulation property of the BN insulated tube at high temperatures rapidly decreases after reaching 1600℃, so take this into account and set the temperature to 1600℃ or less. is preferred.

However, as mentioned above, even if the thermocouple rod member and the insulating tube come into contact at the point (B) in FIG. 1, it is sufficient to achieve the intended purpose of the present invention. the above(
B) Even if the point insertion hole has a small diameter, it is preferable to make it non-contact in order to prevent the occurrence of shunt errors. Since contact does not occur in areas other than the top, the desired effect can be fully expected.

Next, an actual test situation using the temperature measuring device of the present invention will be described.

(Test example 1) As a thermocouple wire, a rod diameter of 3 m and a length of 800 = W-
5% Re and W-26% Re rod members were prototyped, and both ends were threaded with M3X0.5. Also, W-26%Rθ as a fastening button, W-5%Re as a nut,
A prototype of W-26% ReO was made using the same rod as the material used to make the thermocouple rod member.

On the other hand, as an insulating tube, a BN with an outer diameter of 12 mm and a length of 50 mm was prototyped, and the diameter of the rod member insertion hole was set to 4 mm. In addition, two 2.2 m through holes were provided separately from the rod member insertion hole, and a W bar with an outer diameter of 2 was inserted over the entire length, so that the rod member insertion holes were concentric.

In addition, the temperature of the HIP device was set at 1600°C with a furnace chamber temperature of 2000°C.
The rod member insertion hole diameter of the insulation pipe located in the temperature range below ℃ was set to 3.2 degrees.

Thus, from the above configuration, the contact between the rod member of the thermocouple and the insulating tube in the furnace chamber was limited to the point shown in FIG. 1(B).

For the above combinations of thermocouple rond members and insulating tubes, BN
Cover with a protective tube and assemble the thermocouple unit by h”1.A.
A repeated durability test of r l OO, 0K94 x 2000°C x 1 hr was conducted.

At this time, for comparison, HO3KINS o,! 5
t+o++φ, W-Rθ%6 thermocouple, same 1. omφ, W
A similar test was conducted using a Re 4 thermocouple and a configuration similar to that of the present invention described above, but with no particular consideration given to contact with the insulating tube, as control products.

As a result, the lifespan of a 0.5■φ thermocouple is 1 cycle at most.
1. While the lifespan of the omφ thermocouple was 2 to 3 cycles, the prototype thermocouple had a lifespan of at least 10 cycles with an accuracy guarantee of ±1.0% even when no consideration was given to contact with the insulating tube. In the case of the example of the present invention, in which special consideration was given to ensuring this, the life span was improved by more than 1.5 times compared to the above case.

(Test Example 2) Next, in addition to the above configuration, BeO was added as a spacer between the uppermost insulating tube and the fastening button.
, Y2O3 was used to conduct a durability test.

This result also shows that Ar l
OOOK%
An average improvement of 18% was achieved compared to the case where no spacer was used.

(f) Effects of the Invention As described above, the present invention provides a temperature measuring device for a high-temperature and high-pressure furnace, in which the thermocouple wire is made into a rod member with a large diameter, and the rod member insertion hole of the insulating tube is made larger in diameter than the rod member. Each rod member is held suspended in the rod member insertion hole of the insulated tube with almost no contact with the insulated tube, and by using a large diameter thermocouple rod member, the crystal grains of the thermocouple wire This results in a longer service life until breakage due to coarsening, and increases resistance to contamination by impurity gas components in the atmosphere, making it possible to significantly improve service life. It has the remarkable effect of increasing its effectiveness as a temperature measurement device and facilitating the industrial production of high-temperature, high-pressure furnaces such as H-P equipment.
Since it is limited to the two ends of the insulating tube at high temperatures, it is possible to prevent shunt errors due to deterioration of the electrical insulation of the insulating tube at high temperatures, and also to prevent the occurrence of shunt errors due to the decomposition of BN.
It is also possible to suppress the decrease in thermoelectromotive force caused by N diffusion and permeation.
This enables very substantial and highly accurate flik measurement.

Moreover, in the present invention, the thermocouple rod member is held suspended from the upper end of the insulating tube, and the lower part is in a free state, and as mentioned above, there is almost no contact between the rod member and the insulating tube. Therefore, the elongation caused by thermal expansion of the individual rod members can be absorbed downward, and damage caused by thermal expansion, which is often seen in thermocouples of the same type, is not caused.

In addition, BN is often used for insulation tubes and protection tubes, and EeO
, Th02, HfO2, and Y2O3 can be expected to have the advantage of making it possible to construct a thermocouple that is extremely effective in improving the accuracy of thermoelectromotive force under high temperatures and at low cost.

[Brief explanation of the drawing]

Figure 1 (a) shows one of the thermocouple units used in the device of the present invention.
A partially omitted cross-sectional view showing an example, FIG. 1(B) is a view taken along the line X-X in FIG. Partially enlarged explanatory diagram, Figure 3 (a)
(b) is a top view of the insulating tube and a partially approximated Y-Y cross section in (a), and Figures 4 (a), (b) and 5 (a) and (b) are concentric with the insertion hole of the insulating tube. In each of the other configuration examples for (a)
is a top view, and (b) is a longitudinal sectional view taken in the direction of (a). Also the 6th
The figure is a partially omitted sectional view showing another embodiment of the thermocouple unit used in the present invention, and FIGS. FIG. 8 is an enlarged view of the upper and lower parts, and is a schematic cross-sectional view of the H-P device to which the conventional temperature measuring means is applied. (T)...Thermocouple unit), (1)...
··thermocouple. (2)・・・・・・Plus side Rondo is kidnapped. (3)・・・・・・Minus side rod member. (4)・・・・・・Button for tightening rod members. (5) (6)...upper oak), (7)(8)・
...Natsuto at the bottom. (9) α0)...Lead wire, (11)...
・Insulating tube. (2)・・・・・・Protection tube. (1a) (ta5 (13a) (13a')...-o Rad member insertion hole. (1→α5)...Through hole, 06)...Spacer. α7) (2))...Through hole, (20)...
pressure vessel. (23)・・・・・・Furnace room. Figure 2 (A) (B) Ko Y y'' Figure 7 (A) Figure 8 f 2

Claims (1)

[Claims] 1. An insulated tube with an insertion hole is housed in a protective tube, a thermocouple wire is inserted into the insulated tube, and the thermocouple wire is held vertically downward at the upper end of the insulated tube. In a temperature measuring device for a high-pressure furnace, 1) 'J heat recording' cross-pair wires are used as large-diameter plus side and minus side rond parts 4'A, and respective corresponding thermocouple rond parts 4J insertion holes of the insulating tube are connected. The hole diameter is compared to the diameter of each rod member, and a gap is left between each rod member and each rod member insertion hole of the insulating tube at least in a high temperature region, so that each rod member is almost not in contact with each other. A temperature measuring device for a high-temperature, high-pressure furnace, characterized in that the temperature measuring device is suspended in an insertion hole of an insulating tube. 2. The temperature measuring device for a high-temperature, high-pressure furnace according to claim 1, wherein the diameter of the thermocouple rod member insertion hole of at least one insulating tube in the lower low temperature region is made approximately the same diameter as the rod member diameter. 8. Temperature measurement in a high-temperature, high-pressure furnace according to claim 1 or 2, wherein the thermocouple is made of W or/and W-Re based material, and the insulating tube is made of BN at least in the high temperature region. Device. 4. A temperature measuring device for a high-temperature, high-pressure furnace according to claim 1, 2, or 3, wherein the diameter of the rod member of the thermocouple is 3 mm or more. 5. The insulating tube is constructed by stacking a plurality of short insulating tubes in multiple stages.81: Claims 1 and 2. 42. A temperature measuring device for a high-temperature, high-pressure furnace according to item 8 or 41. 6. The means for concentrically holding the short insulating tubes stacked in multiple stages is two through holes provided in the insulating tube together with a thermocouple rod member insertion hole, and a bar inserted into the through holes. A temperature measuring device for a high-temperature, high-pressure furnace according to scope 5. 7. The temperature measuring device for a high-temperature and high-pressure furnace according to claim 6, wherein the material of the rod is W or/and W-Re thread material. 8. A means for holding a plurality of short insulating tubes stacked in multiple stages concentrically in the axial direction includes two through holes provided in the insulating tube together with a thermocouple port insertion hole, and a means inserted into the through holes. 6. The temperature measurement device for a high-temperature and high-pressure furnace according to claim 5, wherein the thermocouple wire is a thermocouple wire with known thermoelectromotive force characteristics for testing thermocouple rond members. 9. Temperature control in a high-temperature, high-pressure furnace according to any one of claims 1 to 8, wherein the thermocouple is held suspended by contacting the upper end of the insulating tube with its Rond member fastening button. 1 measurement device. 10. Claims 1 to 10, in which the thermocouple is suspended and held at the upper end of the insulating tube via a spacer made of a material different from that of the insulating tube, between the upper part of the insulating tube and the Rond member fastening button of the thermocouple. A temperature measuring device in a high-temperature, high-pressure furnace according to any one of Item 8. 11. Spacer material is BeO, Th02, HfO
2. The temperature measuring device in a high-temperature, high-pressure furnace according to claim 10, which is at least one selected from the group consisting of Y2O3.