JP3306425B2 - Ceramic thermocouple for high temperature measurement - Google Patents
Ceramic thermocouple for high temperature measurementInfo
- Publication number
- JP3306425B2 JP3306425B2 JP18183897A JP18183897A JP3306425B2 JP 3306425 B2 JP3306425 B2 JP 3306425B2 JP 18183897 A JP18183897 A JP 18183897A JP 18183897 A JP18183897 A JP 18183897A JP 3306425 B2 JP3306425 B2 JP 3306425B2
- Authority
- JP
- Japan
- Prior art keywords
- protective tube
- temperature measurement
- inner protective
- high temperature
- thermocouple
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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- Measuring Temperature Or Quantity Of Heat (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】この発明は，鉄の溶湯等の高
温の物質を測温する保護管を備えた高温測温用セラミッ
ク熱電対に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ceramic thermocouple for high-temperature temperature measurement provided with a protective tube for measuring a high-temperature substance such as molten iron.
【０００２】[0002]
【従来の技術】従来，約１５００℃の鋳鉄溶湯を測温す
るための熱電対は，材料として比較的に融点が高く，大
気中で安定であるＰｔ−Ｒｈを素線とし，該Ｐｔ−Ｒｈ
素線をアルミナシリカファイバー製のパイプに固定して
作製したものが使用されている。このような熱電対は，
鋳鉄溶湯の測温を約１〜２回程度行った後に，正確な温
度の測定が不能となり，廃棄しているのが現状であり，
熱電対を多回数利用できずに熱電対そのものが極めて高
価なものになっている。2. Description of the Related Art Conventionally, a thermocouple for measuring the temperature of a cast iron melt at about 1500 ° C. has a relatively high melting point as a material and is made of Pt-Rh, which is stable in the atmosphere, as a strand.
What was produced by fixing an element wire to a pipe made of alumina silica fiber is used. Such a thermocouple is
After measuring the temperature of the cast iron molten metal about 1-2 times, accurate measurement of the temperature is no longer possible and it is currently discarded.
Because thermocouples cannot be used many times, thermocouples themselves are extremely expensive.
【０００３】また，シース型熱電対は，Ｗ−Ｒｅを素線
とし，高温で使用される金属シース型部品の保護管とし
て使用され，ステンレススチール（ＳＵＳ）等の金属で
作製されたものが知られている。ＳＵＳシース型熱電対
は，１０００℃以上の雰囲気で使用されるものがあり，
その場合には，インコネル等の特殊耐熱合金で作製され
ている。[0003] A sheath-type thermocouple using W-Re as a strand is used as a protective tube for a metal sheath-type component used at a high temperature, and is known to be made of a metal such as stainless steel (SUS). Have been. Some SUS sheathed thermocouples are used in an atmosphere of 1000 ° C or higher.
In that case, it is made of a special heat-resistant alloy such as Inconel.
【０００４】また，特開平６−１６０２００号公報に
は，気密端子付シース型熱電対が開示されている。該熱
電対は，過渡的な温度変化等により，端子部に温度勾配
が生じても測定誤差を生じさせないものであり，アルメ
ル線とクロメル線の異種金属線からなる熱電対素線をス
テンレス製シース内に無機絶縁材と共に，相互に絶縁し
て収納し，シースの基端側を気密端子部により気密に封
止する。気密端子部のセラミック端板に取り付けられた
２本のコパール製の貫通パイプの内部に絶縁スリーブが
挿入され，各熱電対素線はその内部を通って貫通パイプ
と直接接触せずに外部に引き出されている。Japanese Patent Application Laid-Open No. Hei 6-160200 discloses a sheath-type thermocouple with an airtight terminal. The thermocouple does not cause a measurement error even if a temperature gradient occurs at the terminal due to a transient temperature change or the like, and a thermocouple wire composed of a dissimilar metal wire of an alumel wire and a chromel wire is connected to a stainless steel sheath. The sheath is housed together with the inorganic insulating material while being insulated from each other, and the base end side of the sheath is hermetically sealed by an airtight terminal portion. An insulating sleeve is inserted into the inside of two through-hole pipes made of Kopearl attached to the ceramic end plate of the hermetic terminal section, and each thermocouple wire is drawn out without passing through the inside thereof and directly contacting the through-hole pipe. Have been.
【０００５】[0005]
【発明が解決しようとする課題】ところで，熱電対はそ
の種類に応じて，熱起電力は，次のようになっている。
ＰＲ（Ｐｔ−Ｒｈ）熱電対の熱起電力は，５００℃で
１．２４１ｍＶであり，１０００℃で４．８３３ｍＶで
ある。また，ＣＡ（クロメル−アルメル）熱電対の熱起
電力は，５００℃で２０．６４ｍＶであり，１０００℃
で４１．２６９ｍＶである。更に，Ｗ−Ｒｅ熱電対の熱
起電力は，５００℃で８．６５５ｍＶであり，１０００
℃で１８．２５７ｍＶである。また，Ｐｔ−Ｒｈ熱電対
は，不活性ガス雰囲気での使用はできず，大気中での使
用可能温度は１５００℃が限界温度である。ＣＡ熱電対
は，大気中及び不活性ガス雰囲気中での使用が可能であ
り，両者での使用可能温度は８００℃が限界温度であ
る。更に，Ｗ−Ｒｅ熱電対は，大気中及び不活性ガス雰
囲気中での使用が可能であり，大気中での使用可能温度
は４００℃が限界温度であり，不活性ガス雰囲気中での
使用可能温度は２３００℃が限界温度である。By the way, the thermoelectromotive force is as follows according to the type of the thermocouple.
The thermoelectromotive force of the PR (Pt-Rh) thermocouple is 1.241 mV at 500 ° C. and 4.833 mV at 1000 ° C. The thermoelectromotive force of a CA (Chromel-Alumel) thermocouple is 20.64 mV at 500 ° C. and 1000 ° C.
Is 41.269 mV. Further, the thermoelectromotive force of the W-Re thermocouple is 8.655 mV at 500 ° C.
18.257 mV at ° C. Further, the Pt-Rh thermocouple cannot be used in an inert gas atmosphere, and its usable temperature in the atmosphere is 1500 ° C. as a limit temperature. The CA thermocouple can be used in the atmosphere and in an inert gas atmosphere, and its usable temperature is 800 ° C. in both cases. Further, the W-Re thermocouple can be used in the atmosphere and in an inert gas atmosphere, and the usable temperature in the atmosphere is 400 ° C., which is the limit temperature. The limit temperature is 2300 ° C.
【０００６】Ｐｔ−Ｒｈ素線を用いたＰＲ熱電対につい
て，上記のように，ＰＲ熱電対の熱起電力は，ＣＡ熱電
対の約１／１５であり，Ｗ−Ｒｅ熱電対の約１／７と小
さいため，それらの熱電対に比較して測温の精度が劣
り，応答性が悪いという問題を有している。そのため，
現場においては，溶鉱炉の溶湯を測温するため，溶解炉
の近傍で作業者が温度が安定するまでの約８秒間，その
測定場所に居ることを余儀なくされる。また，熱電対に
よる溶湯の測温に際して，熱電対のＰｔ−Ｒｈ素線に鋳
鉄が付着し，それを除去するための工程は煩雑になり，
しかも現行品は寿命が２回程度の測温であり，熱電対の
交換作業も手間がかかるという問題がある。また，熱電
対におけるＷ−Ｒｅ素線は，大気中では酸化し易く，鋳
鉄溶湯の温度測定には使用できないものである。[0006] Regarding the PR thermocouple using the Pt-Rh strand, as described above, the thermoelectromotive force of the PR thermocouple is about 1/15 of that of the CA thermocouple and about 1/15 that of the W-Re thermocouple. 7, the accuracy of temperature measurement is inferior to those thermocouples, and the response is poor. for that reason,
At the site, in order to measure the temperature of the molten metal in the blast furnace, the operator is forced to stay at the measurement place for about 8 seconds until the temperature stabilizes near the blast furnace. In addition, when measuring the temperature of the molten metal with a thermocouple, the cast iron adheres to the Pt-Rh strand of the thermocouple, and the process for removing the cast iron becomes complicated,
In addition, the current product has a temperature measurement that has a service life of about two times, and there is a problem that the work of replacing the thermocouple is troublesome. Further, the W-Re element wire in the thermocouple is easily oxidized in the atmosphere and cannot be used for measuring the temperature of the molten cast iron.
【０００７】[0007]
【課題を解決するための手段】この発明の目的は，上記
の課題を解決することであり，一対のタングステン−レ
ニウム合金製素線の先端部を結合して測温点を構成し，
これを多孔部材を充填したセラミック製の内側保護管内
に配置し，更に前記内側保護管をサーメット製の外側保
護管又は皮膜の外側保護手段内に内包し，金属溶湯とセ
ラミックスとの反応を阻止し，耐熱性，耐溶損性及び耐
腐食性を向上させると共に，反復使用を可能にした高温
測温用セラミック熱電対を提供することである。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to form a temperature measuring point by connecting the tips of a pair of tungsten-rhenium alloy strands,
This is placed in a ceramic inner protective tube filled with a porous member, and the inner protective tube is further enclosed in an outer protective tube made of cermet or an outer protective means of a film to prevent a reaction between the molten metal and the ceramic. Another object of the present invention is to provide a ceramic thermocouple for high temperature measurement which has improved heat resistance, erosion resistance and corrosion resistance, and which can be used repeatedly.
【０００８】この発明は，窒化珪素及びサイアロンから
選択されるセラミックスから成る内側保護管，前記内側
保護管を内包した状態で前記内側保護管の外側に設けら
れたＭｏをベースとするサーメットから成る外側保護管
又は皮膜の外側保護手段，前記内側保護管内の先端部で
結合された測温部を構成する異なる組成の一対のタング
ステン−レニウム合金製素線，前記内側保護管と前記外
側保護手段との内部で前記素線を内包した状態で充填さ
れた窒化ケイ素を主成分とする多孔部材，及び前記外側
保護手段の端部に設けられた前記外側保護手段内を密封
する第１封止部材，から成る高温測温用セラミック熱電
対に関する。The present invention provides an inner protective tube made of ceramics selected from silicon nitride and sialon, and an outer tube made of a Mo-based cermet provided outside the inner protective tube while enclosing the inner protective tube. A pair of tungsten-rhenium alloy wires having different compositions constituting a temperature measuring unit joined at the tip of the inner protective tube; A porous member containing silicon nitride as a main component and filled with the element wire therein, and a first sealing member provided at an end of the outer protecting means for sealing the inside of the outer protecting means. And a ceramic thermocouple for high temperature measurement.
【０００９】前記外側保護管の端部に設けられた前記第
１封止部材は，緻密な耐熱部材と前記耐熱部材に接して
配置された耐熱ガラス部材から構成されている。更に，
前記内側保護管の端部には，前記内側保護管内を密封す
る第２封止部材が設けられている。The first sealing member provided at the end of the outer protective tube is composed of a dense heat-resistant member and a heat-resistant glass member disposed in contact with the heat-resistant member. Furthermore,
A second sealing member for sealing the inside of the inner protective tube is provided at an end of the inner protective tube.
【００１０】前記内側保護管と前記外側保護手段との間
には，耐熱ガラス層が設けられている。従って，前記耐
熱ガラス層は，前記外側保護手段に熱衝撃で亀裂が発生
しても，その隙間を埋め，前記内側保護管が金属溶湯に
直接接触することが阻止され，耐久性を向上できる。A heat-resistant glass layer is provided between the inner protective tube and the outer protective means. Therefore, even if the outer protective means is cracked by thermal shock, the heat-resistant glass layer fills the gap and prevents the inner protective tube from directly contacting the molten metal, thereby improving durability.
【００１１】前記外側保護手段内に充填された前記多孔
部材の部分の熱伝導率は，前記内側保護管内に充填され
た前記多孔部材の部分の熱伝導率より小さく構成されて
いる。従って，前記外側保護手段の内部を通じて外部へ
の熱伝導が抑制され，熱電対測温領域の熱容量を小さく
構成でき，熱電対の応答性を向上できる。The thermal conductivity of the portion of the porous member filled in the outer protection means is smaller than the thermal conductivity of the portion of the porous member filled in the inner protective tube. Therefore, heat conduction to the outside through the inside of the outer protection means is suppressed, the heat capacity of the thermocouple temperature measurement area can be reduced, and the responsiveness of the thermocouple can be improved.
【００１２】前記外側保護手段と前記内側保護管とに充
填された前記多孔部材には，Ｎ2 ，Ａｒの不活性ガスが
充填されている。従って，前記内側保護管と前記外側保
護手段との内部に配置されている前記タングステン−レ
ニウム合金製素線が酸化することがなく，前記タングス
テン−レニウム合金製素線の耐熱性を向上でき，耐久性
を向上できる。The porous member filled in the outer protection means and the inner protection tube is filled with an inert gas of N 2 and Ar. Therefore, the tungsten-rhenium alloy wire disposed inside the inner protection tube and the outer protection means is not oxidized, and the heat resistance of the tungsten-rhenium alloy wire can be improved, and the durability can be improved. Performance can be improved.
【００１３】前記外側保護手段は，浸炭処理又は窒化処
理が施され，硬度がアップされている。従って，この高
温測温用セラミック熱電対は，外力に対して強度をアッ
プでき，耐久性を向上できる。The outer protective means is subjected to a carburizing treatment or a nitriding treatment to increase the hardness. Therefore, the ceramic thermocouple for high temperature measurement can increase the strength against external force and can improve the durability.
【００１４】前記内側保護管が配置されている前記外側
保護手段の部分は，金属溶湯内に入る部分を構成してい
る。また，前記外側保護手段の端部には，セラミック繊
維が充填された金属製パイプが取り付けられている。更
に，前記タングステン−レニウム合金製素線の端部に
は，前記金属製パイプ内に延びている補償導線がそれぞ
れ接続されている。The portion of the outer protection means in which the inner protection tube is arranged constitutes a portion that enters the molten metal. A metal pipe filled with ceramic fibers is attached to an end of the outer protection means. Further, a compensating conductor extending into the metal pipe is connected to an end of the tungsten-rhenium alloy strand.
【００１５】また，前記外側保護手段として前記外側保
護管の代わりに溶射皮膜等の前記皮膜で構成した場合に
は，前記皮膜は，Ｍｏ−ＺｒＯ2 ，Ｍｏ−ＺｒＢ2 ，Ｍ
ｏ−ＺｒＮのいずれかから選択されるもので構成するこ
とができる。In the case where the outer protective means is formed of the coating such as a thermal spray coating instead of the outer protective tube, the coating is made of Mo-ZrO 2 , Mo-ZrB 2 , M
It can be composed of one selected from o-ZrN.
【００１６】この高温測温用セラミック熱電対は，上記
のように，窒化ケイ素等のセラミックスから成る前記内
側保護管がサーメットから成る前記外側保護手段で被覆
され，前記内側保護管が直接鉄の溶湯に接触することが
無いので，セラミックスが鉄溶湯と反応せず，耐熱性，
耐溶損性を向上できる。しかも，前記外側保護手段の内
壁面には前記耐熱ガラス層が配置されているので，たと
え前記外側保護手段に亀裂等が発生しても，該亀裂によ
る隙間を前記耐熱ガラス層が埋め，しかもサーメットに
熱衝撃による亀裂が発生しても，壊滅的な破壊が発生す
ることがなく，しかもセラミックスの前記内側保護管が
鉄の溶湯に直接接触せず，耐熱性，耐溶損性を向上でき
る。また，前記Ｗ−Ｒｅ素線は不活性ガス中に封入され
ているので，Ｗ−Ｒｅ線の熱起電力が比較的に大きく，
温度への応答性が良好になり，しかもＷ−Ｒｅ線の融点
が３０００℃であり，鋳鉄溶湯中で溶けることはない。In this ceramic thermocouple for high temperature measurement, as described above, the inner protective tube made of ceramics such as silicon nitride is covered with the outer protective means made of cermet, and the inner protective tube is directly made of molten iron. Ceramics does not react with the molten iron,
Melting resistance can be improved. Moreover, since the heat-resistant glass layer is disposed on the inner wall surface of the outer protection means, even if a crack or the like occurs in the outer protection means, the heat-resistant glass layer fills the gap caused by the crack, and furthermore, the cermet Even if a crack occurs due to thermal shock, catastrophic destruction does not occur, and the inner protective tube made of ceramic does not directly contact the molten iron, so that heat resistance and erosion resistance can be improved. Further, since the W-Re wire is sealed in an inert gas, the W-Re wire has a relatively large thermoelectromotive force,
Responsiveness to temperature is improved, and the melting point of the W-Re wire is 3000 ° C., so that it does not melt in molten cast iron.
【００１７】[0017]
【発明の実施の形態】以下，図１を参照して，この発明
による高温測温用セラミック熱電対の実施例を説明す
る。図１はこの高温測温用セラミック熱電対の実施例を
示す断面図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a ceramic thermocouple for high temperature measurement according to the present invention will be described below with reference to FIG. FIG. 1 is a sectional view showing an embodiment of the ceramic thermocouple for high temperature measurement.
【００１８】図１に示すように，この高温測温用セラミ
ック熱電対は，外側保護手段として外側保護管１を用
い，外側保護管１の内部に内側保護管２が封入され，耐
熱性，耐溶損性を向上させたものである。タングステン
−レニウム合金製素線（Ｗ−Ｒｅ素線）６，７は，内側
保護管２と外側保護管１に跨がって延びるように配置さ
れている。Ｗ−Ｒｅ素線６，７の酸化腐食による断線を
阻止するため，外側保護管１と内側保護管２には，窒化
ケイ素を主成分とする多孔材から成る多孔部材３，４が
充填されている。内側保護管２は，窒化ケイ素（Ｓｉ3
Ｎ4 ），サイアロン（ｓｉａｌｏｎ）及び炭化ケイ素
（ＳｉＣ）から選択されるセラミックスによって作製さ
れている。また，外側保護管１は，Ｍｏをベースにした
炭化物系サーメント，或いは窒化物系サーメットから作
製されている。また，外側保護手段を溶射皮膜等の皮膜
で構成した場合には，皮膜は，Ｍｏ−ＺｒＯ2 ，Ｍｏ−
ＺｒＢ2 ，Ｍｏ−ＺｒＮのいずれかから選択できる。皮
膜は，外側保護管１の場合と比較して同様の効果を得る
ことができるので，ここでは，皮膜を外側保護管と同一
の符号１で示すこととする。As shown in FIG. 1, this ceramic thermocouple for high temperature measurement uses an outer protective tube 1 as an outer protective means, and an inner protective tube 2 is sealed inside the outer protective tube 1 to provide heat resistance and melting resistance. This is an improvement in loss. The tungsten-rhenium alloy wires (W-Re wires) 6, 7 are arranged so as to extend over the inner protection tube 2 and the outer protection tube 1. The outer protective tube 1 and the inner protective tube 2 are filled with porous members 3 and 4 made of a porous material containing silicon nitride as a main component, in order to prevent disconnection of the W-Re wires 6 and 7 due to oxidative corrosion. I have. The inner protective tube 2 is made of silicon nitride (Si 3
It is made of ceramics selected from N 4 ), sialon and silicon carbide (SiC). The outer protective tube 1 is made of a carbide-based cermet or a nitride-based cermet based on Mo. When the outer protection means is composed of a coating such as a thermal spray coating, the coating is made of Mo-ZrO 2 , Mo-
ZrB 2, can be selected from any one of the Mo-ZrN. Since the coating can obtain the same effect as compared with the case of the outer protective tube 1, here, the film is denoted by the same reference numeral 1 as the outer protective tube.
【００１９】この高温測温用セラミック熱電対は，主と
して，上記セラミックスから成る内側保護管２，内側保
護２を内包した状態で内側保護管２の外側に設けられた
外側保護管１又は皮膜１の外側保護手段（以下，外側保
護手段は，外側保護管１を代表として説明する），内側
保護管２内の先端部の結合部２０で測温部を構成する異
なる組成の一対のＷ−Ｒｅ素線６，７，内側保護管２と
外側保護管１との内部でＷ−Ｒｅ素線６，７を内包した
状態で充填された窒化ケイ素を主成分とする多孔部材
３，４，及び外側保護管１の端部に設けられた外側保護
管１内を密封する第１封止部材９から構成されている。
また，内側保護管２が配置されている外側保護管１の部
分は，測温する対象物，例えば，金属溶湯内に入る部分
を構成している。The ceramic thermocouple for high temperature measurement mainly comprises an outer protective tube 1 or a coating 1 provided outside the inner protective tube 2 with the inner protective tube 2 and the inner protective 2 made of the above ceramics included therein. A pair of W-Re elements having different compositions constituting a temperature measuring unit at an outer protective means (hereinafter, the outer protective means will be described by taking the outer protective tube 1 as a representative) and a connecting portion 20 at the tip end in the inner protective tube 2. Wires 6,7, porous members 3,4 containing silicon nitride as a main component and filled with W-Re wires 6,7 inside inner protective tube 2 and outer protective tube 1, and outer protective member It comprises a first sealing member 9 for sealing the inside of the outer protective tube 1 provided at the end of the tube 1.
Further, the portion of the outer protective tube 1 where the inner protective tube 2 is arranged constitutes a portion that enters an object to be measured, for example, a molten metal.
【００２０】この高温測温用セラミック熱電対におい
て，特に，サーメットから作製された外殻を構成する外
側保護管１は，耐熱性，耐溶損性に優れ，しかも，熱衝
撃で亀裂が発生しても緩やかに破壊に至り，例えば，セ
ラミックスから成る外殻のような壊滅的な破壊に至るこ
とがない。更に，外側保護管１は，浸炭処理又は窒化処
理が施され，硬度がアップされている。また，外側保護
管１内に封入された内側保護管２は，窒化ケイ素を主成
分とするセラミックスから作製され，窒化ケイ素は鉄と
反応し，溶損が激しく，サーメットに比較して熱衝撃性
が劣るが，内側保護管２は鉄の溶湯に直接接触すること
がないので，熱伝達率を小さくすることができ，従っ
て，内側保護管２が熱衝撃で破損することが防止され
る。In this ceramic thermocouple for high temperature measurement, the outer protective tube 1 constituting the outer shell made of cermet is particularly excellent in heat resistance and erosion resistance, and cracks are generated by thermal shock. Also leads to a gradual destruction without catastrophic destruction, for example, of an outer shell made of ceramics. Further, the outer protective tube 1 is subjected to a carburizing treatment or a nitriding treatment to increase the hardness. The inner protective tube 2 enclosed in the outer protective tube 1 is made of a ceramic containing silicon nitride as a main component, and silicon nitride reacts with iron, and is severely eroded. However, since the inner protective tube 2 does not come into direct contact with the molten iron, the heat transfer coefficient can be reduced, so that the inner protective tube 2 is prevented from being damaged by thermal shock.
【００２１】この高温測温用セラミック熱電対は，外側
保護管１と内側保護管２との合計の熱容量を小さく構成
できるので，保護管を二重構造に構成しても，温度測定
の応答性を低下させることはない。更に，内側保護管２
と外側保護管１との間には，耐熱ガラス層５が設けられ
ている。従って，耐熱ガラス層５は，外側保護管１と内
側保護管２との固定温度熱伝導性を向上させることがで
き，特に，外側保護管１に亀裂が発生した場合には，そ
の亀裂の部分へ浸入し，亀裂による隙間を埋める作用を
し，外側保護管１の壊滅的な破壊を阻止することができ
る。The ceramic thermocouple for high temperature measurement can reduce the total heat capacity of the outer protective tube 1 and the inner protective tube 2, so that the responsiveness of the temperature measurement can be obtained even if the protective tube is formed in a double structure. Is not reduced. Furthermore, the inner protective tube 2
A heat-resistant glass layer 5 is provided between the outer protective tube 1 and the outer protective tube 1. Therefore, the heat-resistant glass layer 5 can improve the fixed-temperature thermal conductivity between the outer protective tube 1 and the inner protective tube 2, and particularly, when a crack occurs in the outer protective tube 1, a portion of the crack is generated. And acts to fill gaps due to cracks, thereby preventing catastrophic destruction of the outer protective tube 1.
【００２２】外側保護管１の端部に設けられた第１封止
部材は，窒化ケイ素等の緻密な耐熱部材９と耐熱部材９
に接して配置された耐熱ガラス部材１０から二重構造に
構成されている。更に，内側保護管２の端部には，内側
保護管２内を密封する耐熱ガラス，窒化ケイ素等の緻密
な耐熱材から成る封止部材８が設けられている。外側保
護管１と内側保護管２との内部に，Ｎ2 やＡｒの不活性
ガスを封入するため，内側保護管２の端部には封止部材
８が嵌合して密閉状態に配置され，外側保護管１の端部
には窒化ケイ素等の耐熱部材９及び耐熱ガラス部材１０
が嵌合して密閉状態に配置されている。外側保護管１と
内側保護管２との内部にＮ2 やＡｒの不活性ガスを封入
することによって，Ｗ−Ｒｅ素線６，７の酸化を防止す
るように構成されている。The first sealing member provided at the end of the outer protective tube 1 includes a dense heat-resistant member 9 such as silicon nitride and a heat-resistant member 9.
Is formed in a double structure from the heat-resistant glass member 10 arranged in contact with. Further, a sealing member 8 made of a dense heat-resistant material such as heat-resistant glass or silicon nitride for sealing the inside of the inner protective tube 2 is provided at an end of the inner protective tube 2. In order to fill an inert gas such as N 2 or Ar into the inside of the outer protection tube 1 and the inner protection tube 2, a sealing member 8 is fitted to the end of the inner protection tube 2 and is arranged in a sealed state. At the end of the outer protective tube 1, a heat-resistant member 9 such as silicon nitride and a heat-resistant glass member 10 are provided.
Are fitted and arranged in a sealed state. By sealing an inert gas such as N 2 or Ar inside the outer protective tube 1 and the inner protective tube 2, the W-Re wires 6 and 7 are configured to be prevented from being oxidized.
【００２３】また，外側保護管１内に充填された多孔部
材３の部分の熱伝導率は，内側保護管２内に充填された
多孔部材４の部分の熱伝導率より小さく構成されてい
る。例えば，多孔部材３は，多孔部材４よりも空隙が多
い構造に構成することによって熱伝導率を小さく構成す
ることができる。従って，この高温測温用セラミック熱
電対は，鉄等の金属の溶湯に入れられる内側保護管２が
位置する測温領域の熱容量を小さく構成でき，該測温領
域から後方の領域への熱の伝導を阻止できる。The thermal conductivity of the portion of the porous member 3 filled in the outer protective tube 1 is smaller than the thermal conductivity of the portion of the porous member 4 filled in the inner protective tube 2. For example, the heat conductivity of the porous member 3 can be reduced by configuring the porous member 3 to have a structure having more voids than the porous member 4. Therefore, this ceramic thermocouple for high temperature measurement can be configured to have a small heat capacity in the temperature measurement area where the inner protective tube 2 placed in the molten metal such as iron is located, and to transfer heat from the temperature measurement area to the rear area. Conduction can be blocked.
【００２４】外側保護管１の端部には，セラミック繊維
１２が充填された金属製パイプ１１が固定リング２１を
介して取り付けられている。外側保護管１には固定リン
グ２１が固着されており，固定リング２１が金属製パイ
プ１１に固定金具１６によって固定されている。セラミ
ック繊維１２は，例えば，ＳｉＣウィスカー等のセラミ
ック繊維，或いはＳｉ3 Ｎ4 系反応焼結セラミックスか
ら成る材料で構成されている。また，Ｗ−Ｒｅ素線６，
７の端部には，金属製パイプ１１内に延びている補償導
線１３がそれぞれ接続されている。また，外側保護管１
から延び出したＷ−Ｒｅ素線６，７は，接続ねじ１７に
よって補償導線１３にそれぞれ接続 されている。補償
導線１３は，一方がプラス端子１８を形成し，他方がマ
イナス端子１９を形成している。金属製パイプ１１の端
部には，二重の窒化ケイ素製栓１５によって封止されて
いる。At the end of the outer protective tube 1, a metal pipe 11 filled with ceramic fibers 12 is attached via a fixing ring 21. A fixing ring 21 is fixed to the outer protective tube 1, and the fixing ring 21 is fixed to the metal pipe 11 by a fixing bracket 16. The ceramic fiber 12 is made of, for example, a ceramic fiber such as a SiC whisker or a material made of a Si 3 N 4 -based reaction sintered ceramic. In addition, W-Re strand 6,
7 are connected to compensating conductors 13 extending into the metal pipe 11, respectively. In addition, outer protective tube 1
The W-Re wires 6 and 7 extending from the wire are connected to the compensating conductor 13 by connection screws 17 respectively. One of the compensating leads 13 forms a plus terminal 18 and the other forms a minus terminal 19. The end of the metal pipe 11 is sealed with a double silicon nitride stopper 15.
【００２５】−実施例− 実施例では，一対のＷ−Ｒｅ素線６，７は，互いに異な
った組成を有するＷ−５ＲｅとＷ−２６Ｒｅからそれぞ
れ構成され，それぞれ線径が０．５ｍｍであり，長さが
３００ｍｍであり，先端部が互いに溶接で結合されてい
る結合部２０を備えている。まず，Ｗ−Ｒｅ素線６，７
を窒化ケイ素を主成分とする原料粉末で着肉した。原料
粉末が着肉したＷ−Ｒｅ素線６，７を，外径が６．５ｍ
ｍ，長さが１２０〜１５０ｍｍの窒化ケイ素製の内側保
護管２内に配置し，内側保護管２内に上記原料粉末を充
填した。内側保護管２内に不活性ガスを注入して内側保
護管２の端部を耐熱ガラスから成る封止部材８で密封し
た。Embodiment In the embodiment, a pair of W-Re wires 6 and 7 are respectively composed of W-5Re and W-26Re having different compositions, each having a wire diameter of 0.5 mm. , Having a length of 300 mm and having a joining portion 20 whose tips are joined to each other by welding. First, W-Re wires 6, 7
With a raw material powder containing silicon nitride as a main component. W-Re wires 6 and 7 on which the raw material powder has been deposited have an outer diameter of 6.5 m.
m, was placed in an inner protective tube 2 made of silicon nitride having a length of 120 to 150 mm, and the inner protective tube 2 was filled with the raw material powder. An inert gas was injected into the inner protective tube 2 and the end of the inner protective tube 2 was sealed with a sealing member 8 made of heat-resistant glass.
【００２６】次いで，内側保護管２を，Ｍｏ／ＺｒＯ2
から成るサーメットで作製された内径が７ｍｍの外側保
護管１内に挿入すると共に，外側保護管１と内側保護管
２との隙間を耐熱ガラスを充填して耐熱ガラス層５で固
定した。更に，外側保護管１内には，繊維等を多く配合
して気孔両を多くした窒化ケイ素を主成分とする原料粉
末を充填すると共に，不活性ガスを注入し，外側保護管
１の端部に封止部材を構成する耐熱部材９と耐熱ガラス
部材１０とによって封止した。更に，Ｗ−Ｒｅ素線６，
７のそれぞれの端部に補償導線１３を接続すると共に，
外側保護管１に固定用リング２１を固着し，固定用リン
グ２１にステンレススチール等の金属パイプ１１を接続
した。次いで，金属パイプ１１内にセラミック繊維を充
填し，金属パイプ１１の端部を栓１５で封止した。上記
のようにして，この発明による高温測温用セラミック熱
電対を作製した。Next, the inner protective tube 2 is replaced with Mo / ZrO 2
The inner protective tube 1 was inserted into the outer protective tube 1 having an inner diameter of 7 mm and made of cermet, and the gap between the outer protective tube 1 and the inner protective tube 2 was filled with heat-resistant glass and fixed with the heat-resistant glass layer 5. Further, the inside of the outer protective tube 1 is filled with a raw material powder mainly composed of silicon nitride having a large amount of pores by blending a large amount of fibers and the like, and an inert gas is injected thereinto. Then, sealing was performed by a heat-resistant member 9 and a heat-resistant glass member 10 constituting a sealing member. Furthermore, the W-Re strand 6,
7 is connected to a compensating lead 13 at each end.
A fixing ring 21 was fixed to the outer protective tube 1, and a metal pipe 11 such as stainless steel was connected to the fixing ring 21. Next, the metal pipe 11 was filled with ceramic fibers, and the end of the metal pipe 11 was sealed with a stopper 15. As described above, the ceramic thermocouple for high temperature measurement according to the present invention was manufactured.
【００２７】上記のように構成した高温測温用セラミッ
ク熱電対を使用して，約１４５０℃の鋳鉄溶湯の測温を
行ったところ，原料粉末が焼成され，安定化するまでの
時間は約１０秒かかったが，２００サイクル繰り返し
た。外側保護管１には，亀裂が認められたが，物質の測
温性能には問題がなく，その状態で１０００回以上の鋳
鉄溶湯の測温を行ったが，高温測温用セラミック熱電対
の起電力の変化はなく，安定して測温することができ
た。When the temperature of the molten cast iron at about 1450 ° C. was measured using the ceramic thermocouple for high temperature temperature measurement constructed as described above, it took about 10 hours for the raw material powder to be fired and stabilized. It took seconds, but repeated 200 cycles. Although cracks were observed in the outer protective tube 1, there was no problem in the temperature measurement performance of the material. In this state, the temperature of the cast iron melt was measured 1000 times or more. There was no change in the electromotive force, and the temperature could be measured stably.
【００２８】また，鋳鉄溶湯の測温とは別に，上記の高
温測温用セラミック熱電対を使用して，約１５００℃の
金属溶湯の連続測温を行ったところ，５００時間以上経
過した時点においても，この高温測温用セラミック熱電
対の起電力の変化等の異常は確認できなかった。即ち，
この高温測温用セラミック熱電対は，耐熱性，耐溶損性
が良好であることが分かった。Separately from the temperature measurement of the molten cast iron, continuous measurement of the temperature of the molten metal at about 1500 ° C. was performed using the ceramic thermocouple for high temperature measurement described above. However, no abnormality such as a change in electromotive force of the ceramic thermocouple for high temperature measurement could be confirmed. That is,
This ceramic thermocouple for high temperature measurement was found to have good heat resistance and erosion resistance.
【００２９】[0029]
【発明の効果】この発明による高温測温用セラミック熱
電対は，上記のように，外殻はＭｏをベースにしたサー
メット等から成る外側保護手段で保護されているので，
耐熱性，耐溶損性を向上でき，反復使用しても，溶湯等
の被測温物体の温度を高精度に且つ迅速に測定でき，そ
の寿命を向上させることができる。また，測温領域の温
度は，内側保護管内の多孔部材によってその領域が制限
され，前記外側保護手段内を通じて後方へ熱が逃げ難く
なり，測温領域の熱容量を小さく構成でき，熱電対の測
温応答性を向上させることができる。As described above, in the ceramic thermocouple for high temperature measurement according to the present invention, the outer shell is protected by the outer protective means such as a cermet based on Mo.
The heat resistance and the erosion resistance can be improved, and the temperature of an object to be measured such as a molten metal can be measured with high accuracy and speed even if it is used repeatedly, and its life can be improved. In addition, the temperature of the temperature measurement area is limited by the porous member in the inner protective tube, and it is difficult for heat to escape backward through the outer protection means, so that the heat capacity of the temperature measurement area can be reduced, and the thermocouple can be measured. Temperature responsiveness can be improved.
【図１】この発明による高温測温用セラミック熱電対の
一実施例を示す断面図である。FIG. 1 is a sectional view showing an embodiment of a ceramic thermocouple for high temperature measurement according to the present invention.
１ 外側保護管（皮膜） ２ 内側保護管 ３，４ 多孔部材 ５ 耐熱ガラス層 ６，７ タングステン−レニウム合金製素線 ８ 封止部材（第２封止部材） ９ 耐熱部材（第１封止部材） １０ 耐熱ガラス部材（第１封止部材） １１ 金属製パイプ １２ セラミック繊維 １３ 補償導線 １６ 固定金具 １７ 接続ねじ ２０ 接合部 DESCRIPTION OF SYMBOLS 1 Outer protective tube (coating) 2 Inner protective tube 3, 4 Porous member 5 Heat resistant glass layer 6, 7 Tungsten-rhenium alloy strand 8 Sealing member (second sealing member) 9 Heat resistant member (first sealing member) 10) Heat-resistant glass member (first sealing member) 11 Metal pipe 12 Ceramic fiber 13 Compensating conductor 16 Fixing bracket 17 Connection screw 20 Joint
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) G01K 7/02 G01K 1/08 ──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 7 , DB name) G01K 7/02 G01K 1/08
Claims (11)
セラミックスから成る内側保護管，前記内側保護管を内
包した状態で前記内側保護管の外側に設けられたＭｏを
ベースとするサーメットから成る外側保護管又は皮膜の
外側保護手段，前記内側保護管内の先端部で結合された
測温部を構成する異なる組成の一対のタングステン−レ
ニウム合金製素線，前記内側保護管と前記外側保護手段
との内部で前記素線を内包した状態で充填された窒化ケ
イ素を主成分とする多孔部材，及び前記外側保護手段の
端部に設けられた前記外側保護手段内を密封する第１封
止部材，から成る高温測温用セラミック熱電対。1. An inner protective tube made of ceramics selected from silicon nitride and sialon, and an outer protective tube made of a Mo-based cermet provided outside the inner protective tube while enclosing the inner protective tube. Alternatively, a pair of tungsten-rhenium alloy strands of different compositions constituting a temperature measuring unit joined at the tip of the inner protective tube, inside the inner protective tube and the outer protective device. A high-temperature member comprising: a porous member containing silicon nitride as a main component and filled with the wire; and a first sealing member provided at an end of the outer protecting member for sealing the inside of the outer protecting member. Ceramic thermocouple for temperature measurement.
記第１封止部材は，緻密な耐熱部材と前記耐熱部材に接
して配置された耐熱ガラス部材から構成されている請求
項１に記載の高温測温用セラミック熱電対。2. The method according to claim 1, wherein the first sealing member provided at an end of the outer protection means is formed of a dense heat-resistant member and a heat-resistant glass member disposed in contact with the heat-resistant member. The ceramic thermocouple for high temperature measurement described.
護管内を密封する第２封止部材が設けられている請求項
１又は２に記載の高温測温用セラミック熱電対。3. The ceramic thermocouple for high temperature measurement according to claim 1, wherein a second sealing member for sealing the inside of the inner protective tube is provided at an end of the inner protective tube.
間には，耐熱ガラス層が設けられている請求項１〜３の
いずれか１項に記載の高温測温用セラミック熱電対。4. The ceramic thermocouple for high temperature temperature measurement according to claim 1, wherein a heat-resistant glass layer is provided between said inner protective tube and said outer protective means.
孔部材の部分の熱伝導率は，前記内側保護管内に充填さ
れた前記多孔部材の部分の熱伝導率より小さく構成され
ている請求項１〜４のいずれか１項に記載の高温測温用
セラミック熱電対。5. The thermal conductivity of the portion of the porous member filled in the outer protection means is smaller than the thermal conductivity of the portion of the porous member filled in the inner protective tube. The ceramic thermocouple for high temperature measurement according to any one of claims 1 to 4.
充填された前記多孔部材にはＮ2 ，Ａｒの不活性ガスが
充填されている請求項１〜５のいずれか１項に記載の高
温測温用セラミック熱電対。6. The method according to claim 1, wherein the porous member filled in the outer protective means and the inner protective tube is filled with an inert gas of N 2 or Ar. Ceramic thermocouple for high temperature measurement.
処理が施されている請求項１〜６のいずれか１項に記載
の高温測温用セラミック熱電対。7. The ceramic thermocouple for high temperature temperature measurement according to claim 1, wherein said outer protection means is subjected to a carburizing treatment or a nitriding treatment.
側保護手段の部分は，金属溶湯内に入る部分を構成して
いる請求項１〜７のいずれか１項に記載の高温測温用セ
ラミック熱電対。8. The high-temperature temperature measuring device according to claim 1, wherein the portion of the outer protective means in which the inner protective tube is disposed constitutes a portion that enters the molten metal. Ceramic thermocouple.
ク繊維が充填された金属製パイプが取り付けられている
請求項１〜８のいずれか１項に記載の高温測温用セラミ
ック熱電対。9. The ceramic thermocouple for high temperature measurement according to claim 1, wherein a metal pipe filled with ceramic fibers is attached to an end of said outer protection means.
線の端部には，前記金属製パイプ内に延びている補償導
線がそれぞれ接続されている請求項９に記載の高温測温
用セラミック熱電対。10. The ceramic thermocouple for high temperature measurement according to claim 9, wherein a compensating conductor extending into the metal pipe is connected to an end of the tungsten-rhenium alloy strand.
−ＺｒＯ2 ，Ｍｏ−ＺｒＢ2 ，Ｍｏ−ＺｒＮのいずれか
から選択されるものである請求項１〜１０のいずれか１
項に記載の高温測温用セラミック熱電対。11. The film of the outer protection means is made of Mo.
-ZrO 2, Mo-ZrB 2, Mo-ZrN any of claims 1 to 10 is selected from any one
The ceramic thermocouple for high temperature measurement according to the paragraph.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18183897A JP3306425B2 (en) | 1997-06-24 | 1997-06-24 | Ceramic thermocouple for high temperature measurement |
| EP98304965A EP0887632A1 (en) | 1997-06-24 | 1998-06-24 | A ceramic thermocouple for measuring temperature of molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18183897A JP3306425B2 (en) | 1997-06-24 | 1997-06-24 | Ceramic thermocouple for high temperature measurement |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1114467A JPH1114467A (en) | 1999-01-22 |
| JP3306425B2 true JP3306425B2 (en) | 2002-07-24 |
Family
ID=16107706
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18183897A Expired - Fee Related JP3306425B2 (en) | 1997-06-24 | 1997-06-24 | Ceramic thermocouple for high temperature measurement |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3306425B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4577703B2 (en) * | 2000-11-20 | 2010-11-10 | いすゞ自動車株式会社 | Thermocouple for melting furnace and temperature measurement method using the same |
| JP2010054491A (en) * | 2008-07-30 | 2010-03-11 | Saginomiya Seisakusho Inc | Temperature measuring sensor and temperature measuring device using the temperature measuring sensor |
-
1997
- 1997-06-24 JP JP18183897A patent/JP3306425B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1114467A (en) | 1999-01-22 |
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| LAPS | Cancellation because of no payment of annual fees |