JP3533944B2 - Structure of thermocouple protection tube with destruction detection function - Google Patents
Structure of thermocouple protection tube with destruction detection functionInfo
- Publication number
- JP3533944B2 JP3533944B2 JP13829098A JP13829098A JP3533944B2 JP 3533944 B2 JP3533944 B2 JP 3533944B2 JP 13829098 A JP13829098 A JP 13829098A JP 13829098 A JP13829098 A JP 13829098A JP 3533944 B2 JP3533944 B2 JP 3533944B2
- Authority
- JP
- Japan
- Prior art keywords
- thermocouple
- protective tube
- detection function
- insulating layers
- conductive layer
- 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
- 238000001514 detection method Methods 0.000 title claims description 23
- 230000006378 damage Effects 0.000 title claims description 20
- 229910052751 metal Inorganic materials 0.000 claims description 58
- 239000002184 metal Substances 0.000 claims description 58
- 230000001681 protective effect Effects 0.000 claims description 50
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 10
- 239000000945 filler Substances 0.000 claims description 10
- 239000000463 material Substances 0.000 claims description 10
- 239000000203 mixture Substances 0.000 claims description 9
- 229910018072 Al 2 O 3 Inorganic materials 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 6
- 239000002131 composite material Substances 0.000 claims description 6
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- 229910052721 tungsten Inorganic materials 0.000 claims description 4
- 229910052804 chromium Inorganic materials 0.000 claims description 3
- 230000015556 catabolic process Effects 0.000 claims 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 10
- 239000000919 ceramic Substances 0.000 description 6
- 238000002844 melting Methods 0.000 description 6
- 230000008018 melting Effects 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- 238000009529 body temperature measurement Methods 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 5
- 229910018967 Pt—Rh Inorganic materials 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 4
- 229910000831 Steel Inorganic materials 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 239000011195 cermet Substances 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 238000005755 formation reaction Methods 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000035939 shock Effects 0.000 description 2
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 229910000809 Alumel Inorganic materials 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004859 Copal Substances 0.000 description 1
- 241000782205 Guibourtia conjugata Species 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 229910001179 chromel Inorganic materials 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- -1 for example Inorganic materials 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 229910001026 inconel Inorganic materials 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 229910003465 moissanite Inorganic materials 0.000 description 1
- 229920001558 organosilicon polymer Polymers 0.000 description 1
- DECCZIUVGMLHKQ-UHFFFAOYSA-N rhenium tungsten Chemical group [W].[Re] DECCZIUVGMLHKQ-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000001052 transient effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- 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，金属溶湯等を測
温する保護管を備えた破壊検知機能付き熱電対用保護管
の構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a protective tube for a thermocouple having a destruction detection function, which has a protective tube for measuring the temperature of molten metal or the like.
【０００２】[0002]
【従来の技術】従来，アルミニウム，銅，鉄等の金属の
溶湯を測温する熱電対は，その保護管の材料として，カ
ーボン，窒化ケイ素，アルミナ或いはＳｉＣが使用され
ている。また，約１７００℃の製鋼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た構造の
ものが使用されている。このような熱電対は，製鋼溶湯
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
多数回にわたって反復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, carbon, silicon nitride, alumina or SiC has been used as a material for a protective tube of a thermocouple for measuring the temperature of molten metal such as aluminum, copper and iron. Further, the thermocouple for measuring the temperature of the molten steel at about 1700 ° C. uses Pt-Rh, which has a relatively high melting point as a material and is stable in the atmosphere, as an element wire, and the Pt-Rh element wire is made of alumina silica. The structure fixed to the fiber pipe is used. Such a thermocouple cannot be accurately measured after measuring the temperature of molten steel for about 1 to 2 times, and it is currently discarded, and the thermocouple is repeatedly used many times. This is not possible, and the thermocouple itself is 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。或いは，熱電対として，保護管をサーメットで
作製して，保護管の内部にＰｔ−Ｒｈを素線とした構造
のものも知られている。A sheath type thermocouple is used as a protective tube for a metal sheath type component which uses W-Re as a wire and is used at a high temperature, and is made of a metal such as stainless steel (SUS). Has been. Some SUS sheath type 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. Alternatively, a thermocouple having a structure in which a protective tube is made of cermet and Pt-Rh is used as a wire inside the protective tube is also known.
【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。Further, Japanese Patent Laid-Open No. 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 in the terminal portion due to a transient temperature change, etc. The thermocouple wire made of dissimilar metal wires such as alumel wire and chromel wire is used as a stainless steel sheath. They are housed together with an inorganic insulating material while being insulated from each other, and the proximal end side of the sheath is hermetically sealed by an airtight terminal portion. An insulating sleeve was inserted into the inside of two through-pipes made of copal attached to the ceramic end plate of the airtight terminal, and each thermocouple wire was pulled out through the inside without making direct contact with the through-pipe. Has been.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら，熱電対
は，溶解炉の湯面から溶湯へ差し込んで溶湯温度を測温
するタイプと，炉底面から炉壁を通して突き出して溶湯
を測温するタイプとがあるが，特に，後者の炉底面から
炉壁を通して突き出して測温するタイプでは，溶湯の測
温中に熱電対が破損すると，破損した熱電対を通じて湯
が溶解炉から外部へ流れ出す現象が発生し，極めて危険
な状態になる。However, there are two types of thermocouples, one is that the temperature of the molten metal is measured by inserting it into the molten metal from the surface of the melting furnace, and the other is that the temperature of the molten metal is measured by protruding from the bottom of the furnace through the furnace wall. However, in particular, in the latter type, in which the temperature is measured by projecting from the bottom of the furnace through the furnace wall, if the thermocouple is damaged during temperature measurement of the molten metal, a phenomenon occurs in which the hot water flows out of the melting furnace through the damaged thermocouple. ， It becomes extremely dangerous.
【０００６】また，サーメット保護管の耐熱衝撃性はＳ
ｉ3 Ｎ4 保護管の１．５倍の強度であり，また，Ｓｉ3
Ｎ4 保護管の熱電対を１７００℃を越える鉄溶湯に直接
浸した場合には，比較的に短時間のうちに保護管に亀裂
等が発生し，破損に至る。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。また，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２３
００℃が限界温度である。Further, the thermal shock resistance of the cermet protection tube is S
i 3 N 4 was 1.5 times the strength of the protective tube, also, Si 3
When the thermocouple of the N 4 protective tube is directly immersed in the molten iron having a temperature of more than 1700 ° C., the protective tube is cracked in a relatively short time and is damaged. In addition, the Pt-Rh thermocouple
It cannot be used in an inert gas atmosphere, and the usable temperature in the atmosphere is 1500 ° C, which is the limit temperature. Also, W-Re
The thermocouple can be used in the atmosphere and in an inert gas atmosphere, and the usable temperature in the atmosphere is 400 ° C as the limit temperature, and the usable temperature in the inert gas atmosphere is 23.
The limit temperature is 00 ° C.
【０００７】[0007]
【課題を解決するための手段】この発明の目的は，上記
の課題を解決するため，熱電対を構成する保護管を積層
構造に構成し，積層構造を絶縁層と導電層との交互の積
層によって構成し，導電層に電極部を接続して導電層が
金属溶湯に接することによって外周から何層目が溶損し
たかを検出し，熱電対の交換時期を認識できる破壊検知
機能付き熱電対用保護管の構造を提供することである。SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, an object of the present invention is to construct a protective tube constituting a thermocouple in a laminated structure, and to arrange the laminated structure in which insulating layers and conductive layers are alternately laminated. A thermocouple with a breakage detection function that can detect the number of layers melted from the outer circumference by connecting the electrode section to the conductive layer and contacting the molten metal with the conductive layer, and recognizing the replacement time of the thermocouple. The purpose is to provide a protective tube structure.
【０００８】この発明は，金属溶湯の測温領域を構成す
る先端部が閉鎖された保護管，前記保護管内に充填され
た充填材，及び前記充填材中に配置され且つ端部が互い
に結合された異なる組成の一対の温度検知用金属素線か
ら成る熱電対において，前記保護管は組成の異なる絶縁
層が交互に積層された積層構造から構成され，前記絶縁
層間には導電層が隔置して順次に挿入積層され，前記導
電層には電流を流すために電極部が設けられていること
を特徴とする破壊検知機能付き熱電対用保護管の構造に
関する。According to the present invention, a protective tube having a closed tip forming a temperature measuring region of molten metal, a filler filled in the protective tube, and a filler arranged in the filler and having ends joined to each other. In a thermocouple composed of a pair of temperature-sensing metal wires having different compositions, the protection tube has a laminated structure in which insulating layers having different compositions are alternately laminated, and conductive layers are arranged between the insulating layers. The present invention relates to a structure of a protective tube for a thermocouple having a breakage detecting function, characterized in that the conductive layer is sequentially inserted and laminated, and an electrode portion is provided on the conductive layer to flow a current.
【０００９】一方の前記絶縁層はＡｌ2 Ｏ3 ，Ｓｉ3 Ｎ
4 又はＳｉＣの材料とＣとの複合材から構成され，他方
の前記絶縁層はＭｇＯから構成されている。或いは，一
方の前記絶縁層はＡｌ2 Ｏ3 ，Ｓｉ3 Ｎ4 又はＳｉＣの
材料とＣとの複合材から構成され，他方の前記絶縁層は
Ｓｉ3 Ｎ4 から構成されている。One of the insulating layers is made of Al 2 O 3 , Si 3 N
It is composed of a composite material of 4 or SiC material and C, and the other insulating layer is composed of MgO. Alternatively, one of the insulating layers is made of a composite material of Al 2 O 3 , Si 3 N 4 or SiC and C, and the other insulating layer is made of Si 3 N 4 .
【００１０】前記導電層は，Ｃ，Ｐｔ，Ｗ，Ｍｏ又はＣ
ｒから成る金属線から構成されている。ここで，測温対
象の金属溶湯が銅溶湯である場合には，前記金属線は，
Ｃｕの融点よりも高く，反応によって溶損しない金属か
ら構成されている。The conductive layer is made of C, Pt, W, Mo or C.
It is composed of a metal wire made of r. Here, when the metal melt whose temperature is to be measured is copper melt, the metal wire is
It is composed of a metal that has a melting point higher than that of Cu and is not melted by the reaction.
【００１１】前記保護管は，表面にアルミナが溶射され
た前記導電層を前記絶縁層間に順次挿入した状態で焼結
されている。The protective tube is sintered in a state in which the conductive layer having alumina sprayed on its surface is sequentially inserted between the insulating layers.
【００１２】前記絶縁層に対する前記導電層の容積は，
５〜１５ｖｏｌ％の範囲に設定されている。The volume of the conductive layer with respect to the insulating layer is
It is set in the range of 5 to 15 vol%.
【００１３】この破壊検知機能付き熱電対用保護管の構
造は，測温対象の金属溶湯が前記導電層に接することに
よって前記電極部を通じて導通状態になり，前記保護管
の破壊状態を検知できるものである。The structure of the protection tube for a thermocouple having a breakage detection function is such that when the metal melt whose temperature is to be measured comes into contact with the conductive layer, it becomes conductive through the electrode portion, and the breakage state of the protection tube can be detected. Is.
【００１４】この破壊検知機能付き熱電対用保護管の構
造は，前記導電層にそれぞれ設けた前記電極部のうちか
ら二本を選択してセンサによって導通状態を測定するこ
とによって前記保護管の破壊状態を検知し，破壊してい
ない残りの前記絶縁層の形成数が所定の形成数以下に達
した時点で前記熱電対の交換時期を判定するものであ
る。即ち，この破壊検知機能付き熱電対用保護管の構造
は，積層構造の積層の形成数に対して，残りの形成層が
予め設定した形成数になった時に，熱電対が破損したと
して新しい熱電対と交換することを決定するものであ
る。The structure of the protection tube for a thermocouple having the destruction detection function is such that the protection tube is destroyed by selecting two of the electrode portions respectively provided on the conductive layers and measuring the conduction state with a sensor. The state is detected, and the time to replace the thermocouple is determined when the number of remaining undestructed insulating layers reaches a predetermined number or less. In other words, the structure of the thermocouple protection tube with the destruction detection function is such that the thermocouple is damaged when the remaining formation layers have a preset formation number with respect to the number of laminated formations of the laminated structure. It decides to exchange for a pair.
【００１５】[0015]
【発明の実施の形態】以下，図面を参照して，この発明
による破壊検知機能付き熱電対用保護管の構造の実施例
を説明する。図１はこの破壊検知機能付き熱電対用保護
管を金属溶湯に浸漬した測温状態を示す概略説明図，図
２はこの破壊検知機能付き熱電対用保護管の構造の実施
例を示す断面図，及び図３は図１の保護管における絶縁
層に対する導電層の体積％と焼結密度との関係を示すグ
ラフである。BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the structure of a thermocouple protective tube with a destruction detecting function according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing a temperature measuring state in which the thermocouple protection tube with the destruction detection function is immersed in a molten metal, and FIG. 2 is a sectional view showing an embodiment of the structure of the thermocouple protection tube with the destruction detection function. , And FIG. 3 are graphs showing the relationship between the volume percentage of the conductive layer with respect to the insulating layer and the sintering density in the protective tube of FIG.
【００１６】この破壊検知機能付き熱電対用保護管の構
造を組み込んだ熱電対は，金属溶湯の測温領域を構成す
る先端部２が閉鎖された保護管１，保護管１内に充填さ
れた充填材８，及び充填材８中に配置され且つ端部が互
いに結合された異なる組成の一対の温度検知用金属素線
９，１０から構成されている。充填材８は，例えば，耐
熱多孔質セラミックスから成り，保護管１の開口部が緻
密な耐熱部材及びガラスから成る封止部材（図示せず）
で封止されている。保護管１は，測温領域を構成する先
端部２が閉鎖され，後方部５の端部が開放した構造（図
示せず）を有している。The thermocouple incorporating the structure of the protective tube for the thermocouple with the destruction detection function is filled in the protective tube 1 and the protective tube 1 whose tip 2 constituting the temperature measuring region of the molten metal is closed. It is composed of a filler 8 and a pair of temperature detecting metal wires 9 and 10 which are arranged in the filler 8 and whose ends are connected to each other and have different compositions. The filler 8 is made of, for example, heat-resistant porous ceramics, and a sealing member (not shown) made of glass and a heat-resistant member having a dense opening in the protective tube 1.
It is sealed with. The protective tube 1 has a structure (not shown) in which a front end portion 2 constituting a temperature measuring region is closed and a rear portion 5 has an open end portion.
【００１７】この破壊検知機能付き熱電対用保護管の構
造は，特に，測温領域の保護管１が積層構造に構成さ
れ，特に，先端部２が組成の異なる絶縁層３，４のみが
交互に積層された積層構造と，後方部５が積層構造の絶
縁層３，４間に導電層７が順次に複数本（図２では４
本）挿入された積層構造とから構成されていることを特
徴とする。即ち，保護管１は，先端部２の積層構造が組
成の異なる絶縁層３（一方の絶縁層）と絶縁層４（他方
の絶縁層）とが交互に積層されており，先端部２の後方
の後方部５の積層構造は絶縁層３，４との間に導電層７
とが順次に積層されている。図２では，導電層７として
は金属線が使用されている。金属線の導電層７の端部に
は電流を流すためにリード線１２から成る電極部が設け
られている。４本のリード線１２には，センサＳが接続
されている。In the structure of the thermocouple protection tube with the destruction detection function, in particular, the protection tube 1 in the temperature measurement region is constructed in a laminated structure, and in particular, only the insulating layers 3 and 4 having different compositions at the tip 2 alternate. And a plurality of conductive layers 7 are sequentially arranged between the insulating layers 3 and 4 having a laminated structure in which the rear part 5 is laminated (see FIG.
The present invention is characterized in that it is composed of an inserted laminated structure. That is, in the protective tube 1, an insulating layer 3 (one insulating layer) and an insulating layer 4 (the other insulating layer) having different composition of the tip portion 2 are alternately laminated, and the rear portion of the tip portion 2 The laminated structure of the rear portion 5 of the conductive layer 7 is formed between the insulating layers 3 and 4.
And are sequentially stacked. In FIG. 2, a metal wire is used as the conductive layer 7. An electrode portion composed of a lead wire 12 is provided at the end of the conductive layer 7 of the metal wire in order to pass a current. The sensor S is connected to the four lead wires 12.
【００１８】一方の絶縁層３はＡｌ2 Ｏ3 ，Ｓｉ3 Ｎ4
又はＳｉＣから選択された材料とＣとの複合材から成
り，他方の絶縁層４はＭｇＯから構成することができ
る。或いは，一方の絶縁層３はＡｌ2 Ｏ3 ，Ｓｉ3 Ｎ4
又はＳｉＣから選択された材料とＣとの複合材から成
り，他方の絶縁層４はＳｉ3 Ｎ4 から構成することがで
きる。One insulating layer 3 is made of Al 2 O 3 , Si 3 N 4
Alternatively, it may be composed of a composite material of C and a material selected from SiC, and the other insulating layer 4 may be composed of MgO. Alternatively, one of the insulating layers 3 is made of Al 2 O 3 , Si 3 N 4
Alternatively, it may be composed of a composite material of C and a material selected from SiC, and the other insulating layer 4 may be composed of Si 3 N 4 .
【００１９】また，導電層７は，Ｃ，Ｐｔ，Ｗ，Ｍｏ又
はＣｒから構成することができる。この時，導電層７の
表面にアルミナが溶射し，その導電層７を絶縁層３，４
間に挿入して順次に挿入して積層し，その積層状態で焼
結することによって保護管１が作製される。更に，絶縁
層３，４に対する導電層７の容積は，５〜１５ｖｏｌ％
の範囲に設定することが焼結密度の関係で好ましいもの
である。The conductive layer 7 can be made of C, Pt, W, Mo or Cr. At this time, alumina is sprayed on the surface of the conductive layer 7, and the conductive layer 7 is covered with the insulating layers 3, 4
The protective tube 1 is manufactured by inserting the layers in the gap, sequentially inserting the layers, laminating the layers, and sintering the layers. Further, the volume of the conductive layer 7 with respect to the insulating layers 3 and 4 is 5 to 15 vol%.
It is preferable to set in the range of because of the sintering density.
【００２０】熱電対によって金属溶湯６を測温する場合
には，図１に示すように，熱電対の保護管１を湯面ＭＳ
より所定の深さまで金属溶湯６中に浸漬させる。金属溶
湯６の測温時に，保護管１の外面の絶縁層３，４から損
傷していくが，その時，測温対象の金属溶湯６が導電層
７に接した時点で，導通状態になり，保護管１の破壊状
態を検知することができる。導電層７にそれぞれ設けた
電極部に接続するリード線１２のうちから二本を選択し
てセンサＳによって導通状態を測定することによって保
護管１の破壊状態を検知することができる。When the temperature of the molten metal 6 is measured by the thermocouple, as shown in FIG.
It is immersed in the molten metal 6 to a predetermined depth. When the temperature of the molten metal 6 is measured, the insulating layers 3 and 4 on the outer surface of the protective tube 1 are damaged. At that time, when the temperature of the molten metal 6 to be measured comes into contact with the conductive layer 7, it becomes conductive. It is possible to detect the broken state of the protective tube 1. The broken state of the protective tube 1 can be detected by selecting two of the lead wires 12 connected to the electrode portions provided on the conductive layer 7 and measuring the conduction state by the sensor S.
【００２１】温度検知用金属素線９，１０は，例えば，
タングステン−レニウム線であり，一方の素線９の組成
がＷ−５Ｒｅであり，他方の素線１０の組成がＷ−２６
Ｒｅである。Ｗ−５Ｒｅ素線９とＷ−２６Ｒｅ素線１０
は，保護管１内の充填材８に埋設された状態で隔置して
延びるように配置されている。Ｗ−５Ｒｅ素線９とＷ−
２６Ｒｅ素線１０の一端部は，測温領域に位置する端部
が互いに結合されて結合部１１を構成している。Ｗ−５
Ｒｅ素線９とＷ−２６Ｒｅ素線１０の他端部は，保護管
１の端部の封止部材から延び出すように構成されてい
る。The temperature detecting metal wires 9 and 10 are, for example,
It is a tungsten-rhenium wire, one of which has a composition of W-5Re, and the other of which has a composition of W-26.
It is Re. W-5Re strand 9 and W-26Re strand 10
Are arranged so as to be spaced apart and extend while being embedded in the filling material 8 in the protective tube 1. W-5Re strand 9 and W-
One ends of the 26Re strands 10 are connected to each other at ends located in the temperature measurement region to form a joint 11. W-5
The other ends of the Re wire 9 and the W-26Re wire 10 are configured to extend from the sealing member at the end of the protective tube 1.
【００２２】充填材８は，例えば，耐熱多孔質セラミッ
クスから成り，該耐熱多孔質セラミックスはＴｉが添加
された反応焼結窒化ケイ素，或いは，Ｓｉ3 Ｎ4 粉末を
含む有機ケイ素ポリマーから転化した無機物と耐熱セラ
ミック粉末との混合物で構成され，その熱伝導率が小さ
く構成されている。例えば，充填材８は，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，この破壊検知機能付き熱電対用保
護管の構造を組み込んだ熱電対は，鉄等の金属の溶湯に
入れられる保護管１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 filler 8 is made of, for example, a heat-resistant porous ceramics, and the heat-resistant porous ceramics is an inorganic substance converted from a reaction-sintered silicon nitride containing Ti or an organosilicon polymer containing Si 3 N 4 powder. And a heat-resistant ceramic powder, and its thermal conductivity is low. For example, the filler 8 can be configured to have a low thermal conductivity by having a structure having many voids. Therefore, the thermocouple incorporating the structure of the protection tube for the thermocouple with the destruction detection function can be configured to have a small heat capacity in the temperature measuring area where the protection tube 1 placed in the molten metal such as iron is located. It is possible to prevent the conduction of heat from the rear area to the rear area.
【００２３】また，積層構造の保護管１は，耐熱性，耐
溶損性に優れ，しかも，多重構造であるので熱衝撃で最
外殻層に亀裂が発生しても内部層へは緩やかに破壊する
ので，例えば，従来の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。また，鉄溶湯の測温
を行なう場合には，保護管１の最外殻層にＭｏを母相と
するサーメット層で構成することによって，鉄の溶湯が
付着することがなく，反復使用が可能になる。更に，保
護管１の内部には，充填材８を充填して製造する時にＮ
2 やＡｒの不活性ガスを封入することもでき，その状態
で保護管１の端部に封止部材が嵌合して密閉状態に構成
することができる。Further, since the protective tube 1 having a laminated structure has excellent heat resistance and erosion resistance, and has a multi-layer structure, even if a crack occurs in the outermost shell layer due to thermal shock, the protective tube 1 is gently broken into the inner layer. Therefore, it does not cause a catastrophic failure such as a conventional outer shell made of ceramics. Further, when measuring the temperature of the molten iron, by constructing the outermost shell layer of the protective tube 1 with a cermet layer having Mo as a mother phase, the molten iron does not adhere and can be used repeatedly. become. Furthermore, the inside of the protective tube 1 is filled with the filling material 8 and N
An inert gas such as 2 or Ar can be filled, and in this state, a sealing member can be fitted to the end of the protective tube 1 to form a sealed state.
【００２４】この破壊検知機能付き熱電対用保護管の構
造は，次のようにして作製できる。アルミナを主成分と
し，該アルミナに少量の焼結助材を添加した混合粉末を
作る。この混合粉末をドクターブレード装置を用いてシ
ートを作製し，該シートを用いて層状，即ち，絶縁層
３，４から成る積層構造の保護管１を成形し，ＣＩＰに
より二次成形を行なった。保護管１の成形に当たって，
絶縁層３，４間には，鋼の融点より高い融点を持つ材
料，例えば，Ｃ，Ｐｔ，Ｗ，Ｍｏ又はＣｒから成る金属
線７を挿入した。金属線７は，積層構造の積層数の半分
よりも内側に挿入して積層した。The structure of the protective tube for a thermocouple having the destruction detection function can be manufactured as follows. A mixed powder containing alumina as a main component and a small amount of a sintering aid added to the alumina is prepared. A sheet was prepared from this mixed powder by using a doctor blade device, and the protective tube 1 having a layered structure, that is, a laminated structure including insulating layers 3 and 4 was formed using the sheet, and secondary molding was performed by CIP. When molding the protective tube 1,
A metal wire 7 made of a material having a melting point higher than that of steel, for example, C, Pt, W, Mo or Cr is inserted between the insulating layers 3 and 4. The metal wire 7 was inserted and laminated inside half of the number of laminated layers of the laminated structure.
【００２５】保護管１を作製するに当たって，積層構造
中に金属線７を挿入積層するため，焼結密度が上がら
ず，強度の低下が発生する。そこで，金属線７の表面に
アルミナ１３を溶射し，アルミナ１３を被覆した金属線
７をシートの積層間に挿入し，焼結を行なった。絶縁層
３，４間に挿入する金属線７の絶縁層３，４に対する体
積量（ｖｏｌ％）と焼結密度との関係は，図３に示すよ
うになった。保護管１の所定以上の強度を確保するため
には，焼結密度は，３．５ｇ／ｃｍ3 以上の値が必要で
あるが，該値に対応する金属線７の絶縁層３，４の体積
量は１５ｖｏｌ％以下であることが必要であり，また，
絶縁層３，４に挿入された金属線７がその強度を確保す
るためには金属線７の絶縁層３，４の体積量は５ｖｏｌ
％以上であることが必要である。従って，金属線７の絶
縁層３，４の体積量は，５〜１５ｖｏｌ％の範囲内であ
ることが適正であることが分かった。When the protective tube 1 is manufactured, since the metal wire 7 is inserted and laminated in the laminated structure, the sintered density does not increase and the strength is reduced. Therefore, alumina 13 was sprayed on the surface of the metal wire 7, the metal wire 7 coated with alumina 13 was inserted between the laminated layers, and sintering was performed. The relationship between the volume density (vol%) of the metal wire 7 inserted between the insulating layers 3 and 4 with respect to the insulating layers 3 and 4 and the sintering density is as shown in FIG. In order to secure the strength of the protective tube 1 above a predetermined level, the sintered density needs to have a value of 3.5 g / cm 3 or more, and the insulating layers 3, 4 of the metal wire 7 corresponding to the value are required. The volume must be 15 vol% or less, and
In order to secure the strength of the metal wire 7 inserted in the insulating layers 3 and 4, the volume of the insulating layers 3 and 4 of the metal wire 7 is 5 vol.
% Or more is required. Therefore, it was found that the volume of the insulating layers 3 and 4 of the metal wire 7 is properly within the range of 5 to 15 vol%.
【００２６】この破壊検知機能付き熱電対用保護管の構
造は，次のようにして使用することができる。図２に示
すように，保護管１に配置された４本の金属線７は，セ
ンサＳに接続されている。センサＳは，４本のうちから
２本を選択して電流を流して導通状態を繰り返して検出
しているが，絶縁層３，４が外周から順次破損して金属
線３，４が挿入されてある導電層に達すると，金属溶湯
６が金属線７に接することになり，選択された一方の金
属線７→金属溶湯６→選択された他方の金属線７の経路
で導通することになり，積層構造の残りの層が何層目に
なったかを検出することができる。そこで，予め決定し
ていた積層の形成数に達したときに，新しい熱電対に交
換すればよいことになる。The structure of the protection tube for a thermocouple having the destruction detection function can be used as follows. As shown in FIG. 2, the four metal wires 7 arranged in the protective tube 1 are connected to the sensor S. The sensor S selects two of the four sensors, detects the current by repeatedly passing the current, and the insulating layers 3 and 4 are sequentially damaged from the outer periphery, so that the metal wires 3 and 4 are inserted. When it reaches a certain conductive layer, the metal melt 6 comes into contact with the metal wire 7, and the metal wire 7 becomes conductive in the path of the selected one metal wire 7 → the metal melt 6 → the other metal wire 7 selected. , It is possible to detect the number of the remaining layers of the laminated structure. Therefore, when a predetermined number of stacked layers is reached, a new thermocouple may be replaced.
【００２７】[0027]
【発明の効果】この発明による破壊検知機能付き熱電対
用保護管の構造は，上記のように積層構造に構成したの
で，耐久性を向上できると共に，熱電対の劣化状態を検
知することができ，それによって交換時期を迅速に認識
できるので，熱電対の破損による金属溶湯の溶融炉から
の漏洩を防止できると共に，熱電対の内部の溶解物が金
属溶湯に混入することを避けることができ，金属溶湯の
信頼性に富んだ測温を可能にし，しかも異物の混入がな
い高精度の金属溶湯を生成することができる。Since the structure of the thermocouple protection tube with the destruction detection function according to the present invention is constructed in the laminated structure as described above, the durability can be improved and the deterioration state of the thermocouple can be detected. ， By this, it is possible to quickly recognize the replacement time, so that it is possible to prevent the molten metal from leaking from the melting furnace due to damage of the thermocouple, and it is possible to prevent the melt inside the thermocouple from mixing with the molten metal. It enables highly reliable temperature measurement of molten metal, and can generate highly accurate molten metal without the inclusion of foreign matter.
【図１】この破壊検知機能付き熱電対用保護管を金属溶
湯に浸漬した測温状態を示す概略説明図である。FIG. 1 is a schematic explanatory view showing a temperature measurement state in which a thermocouple protection tube with a destruction detection function is immersed in molten metal.
【図２】この破壊検知機能付き熱電対用保護管の構造の
実施例を示す断面図である。FIG. 2 is a cross-sectional view showing an embodiment of the structure of the thermocouple protection tube with the destruction detection function.
【図３】図２の保護管における絶縁層に対する導電層の
体積比（ｖｏｌ％）と焼結密度との関係を示すグラフで
ある。3 is a graph showing the relationship between the volume ratio (vol%) of the conductive layer to the insulating layer and the sintered density in the protective tube of FIG.
１ 保護管 ２ 先端部 ３，４ 絶縁層 ５ 後方部 ６ 金属溶湯 ７ 金属線（導電層） ８ 充填材 ９，１０ 金属素線 １１ 結合部 １２ リード線 １３ アルミナ 1 protection tube 2 Tip 3,4 insulating layer 5 rear part 6 molten metal 7 Metal wire (conductive layer) 8 Filling material 9, 10 Metal wires 11 Joint 12 lead wire 13 Alumina
Claims (8)
閉鎖された保護管，前記保護管内に充填された充填材，
及び前記充填材中に配置され且つ端部が互いに結合され
た異なる組成の一対の温度検知用金属素線から成る熱電
対において，前記保護管は組成の異なる絶縁層が交互に
積層された積層構造から構成され，前記絶縁層間には導
電層が隔置して順次に挿入積層され，前記導電層には電
流を流すために電極部が設けられていることを特徴とす
る破壊検知機能付き熱電対用保護管の構造。1. A protective tube having a closed end which constitutes a temperature measuring region of a molten metal, a filler filled in the protective tube,
And a thermocouple composed of a pair of temperature-sensing metal wires of different compositions arranged in the filler and having their ends joined to each other, wherein the protective tube has a laminated structure in which insulating layers having different compositions are alternately laminated. A thermocouple with a breakage detecting function, characterized in that conductive layers are sequentially inserted and laminated at intervals between the insulating layers, and an electrode portion is provided in the conductive layer for passing a current. Protective tube structure.
Ｎ4 又はＳｉＣの材料とＣとの複合材から成り，他方の
前記絶縁層はＭｇＯから成ることを特徴とする請求項１
に記載の破壊検知機能付き熱電対用保護管の構造。2. One of the insulating layers is Al 2 O 3 , Si 3
Made from a composite material with the material and C N 4 or SiC, claim 1 and the other of the insulating layer, characterized in that it consists of MgO
The structure of the thermocouple protection tube with the destruction detection function described in.
Ｎ4 又はＳｉＣの材料とＣとの複合材から成り，他方の
前記絶縁層はＳｉ3 Ｎ4 から成ることを特徴とする請求
項１に記載の破壊検知機能付き熱電対用保護管の構造。3. One of the insulating layers is Al 2 O 3 , Si 3
2. The thermocouple protection tube structure with a breakdown detection function according to claim 1, wherein the protection layer is made of a composite material of N 4 or SiC and C, and the other insulating layer is made of Si 3 N 4 .
Ｃｒから成る金属線から構成されていることを特徴とす
る請求項１〜３のいずれか１項に記載の破壊検知機能付
き熱電対用保護管の構造。4. The destruction detection function according to claim 1, wherein the conductive layer is composed of a metal wire made of C, Pt, W, Mo or Cr. Structure of thermocouple protection tube.
れた前記導電層を前記絶縁層間に順次挿入した状態で焼
結されていることを特徴とする請求項１〜４のいずれか
１項に記載の破壊検知機能付き熱電対用保護管の構造。5. The protective tube is sintered in a state in which the conductive layer having alumina sprayed on its surface is sequentially inserted between the insulating layers. The structure of the thermocouple protection tube with the destruction detection function described in.
は，５〜１５ｖｏｌ％の範囲に設定されていることを特
徴とする請求項１〜５のいずれか１項に記載の破壊検知
機能付き熱電対用保護管の構造。6. The thermoelectric device with a breakdown detection function according to claim 1, wherein the volume of the conductive layer with respect to the insulating layer is set in the range of 5 to 15 vol%. The structure of the protection tube.
ることによって前記電極部を通じて導通状態になり，前
記保護管の破壊状態を検知できることを特徴とする請求
項１〜６のいずれか１項に記載の破壊検知機能付き熱電
対用保護管の構造。7. The molten metal whose temperature is to be measured is brought into conduction through the electrode portion when it comes into contact with the conductive layer, and the broken state of the protective tube can be detected. The structure of the thermocouple protection tube with the destruction detection function described in the item.
のうちから二本を選択してセンサによって導通状態を測
定することによって前記保護管の破壊状態を検知し，破
壊していない残りの前記絶縁層の形成数が所定の形成数
以下に達した時点で前記熱電対の交換時期を判定するこ
とを特徴とする請求項１〜７のいずれか１項に記載の破
壊検知機能付き熱電対用保護管の構造。8. A broken state of the protective tube is detected by selecting two of the electrode portions respectively provided on the conductive layers and measuring a conduction state by a sensor, and the remaining unbroken state of the protective tube is detected. The thermocouple with a breakage detection function according to any one of claims 1 to 7, wherein the replacement time of the thermocouple is determined when the number of insulating layers formed reaches a predetermined number or less. Protective tube structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13829098A JP3533944B2 (en) | 1998-05-20 | 1998-05-20 | Structure of thermocouple protection tube with destruction detection function |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13829098A JP3533944B2 (en) | 1998-05-20 | 1998-05-20 | Structure of thermocouple protection tube with destruction detection function |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11330566A JPH11330566A (en) | 1999-11-30 |
| JP3533944B2 true JP3533944B2 (en) | 2004-06-07 |
Family
ID=15218444
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|---|---|---|---|
| JP13829098A Expired - Fee Related JP3533944B2 (en) | 1998-05-20 | 1998-05-20 | Structure of thermocouple protection tube with destruction detection function |
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| CN100414277C (en) * | 2003-11-14 | 2008-08-27 | 刘元庆 | Thermocouple protective sleeve and manufacturing method thereof |
| KR101416577B1 (en) * | 2012-10-04 | 2014-07-07 | 한국타이어 주식회사 | mixed Thermometer |
| JP5810065B2 (en) * | 2012-11-15 | 2015-11-11 | 株式会社神戸製鋼所 | Protection tube deterioration detection device and method |
-
1998
- 1998-05-20 JP JP13829098A patent/JP3533944B2/en not_active Expired - Fee Related
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| Publication number | Publication date |
|---|---|
| JPH11330566A (en) | 1999-11-30 |
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