JPH0315696B2 - - Google Patents
Info
- Publication number
- JPH0315696B2 JPH0315696B2 JP16233382A JP16233382A JPH0315696B2 JP H0315696 B2 JPH0315696 B2 JP H0315696B2 JP 16233382 A JP16233382 A JP 16233382A JP 16233382 A JP16233382 A JP 16233382A JP H0315696 B2 JPH0315696 B2 JP H0315696B2
- Authority
- JP
- Japan
- Prior art keywords
- flame
- alloy
- flame current
- oxidation
- oxide film
- 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
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/62—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode
- G01N27/626—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating the ionisation of gases, e.g. aerosols; by investigating electric discharges, e.g. emission of cathode using heat to ionise a gas
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Control Of Combustion (AREA)
Description
本発明は燃焼機器のパイロツトバーナーのたち
消え等の監視装置または燃料制御装置等に使用さ
れる炎電流感知センサーに関する。
石油フアンヒーター等には燃料を制御するため
の炎電流感知センサーが使用されている。この炎
電流感知センサーのフレームロツドは長時間繰り
返し高温に加熱されるため、Fe−Cr−Al合金、
Fe−Cr−Al−Ｙ合金、ニツケルクロム合金、ス
テンレス鋼等耐酸化性の優れた材料が用いられる
が、一般には比較的安価で加工性が良く、耐酸化
性が優れたFe−Cr−Al合金やFe−Cr−Al−Ｙ合
金が用いられる。
また炎電流感知センサーのフレームロツドは耐
酸化性と同時に長時間経過後も検知能力が低下し
ないことが必要であるため、表面に生成する酸化
被膜は高温で導電性があることが要求される。
Fe−Cr−Al合金、Fe−Cr−Al−Ｙ合金の場
合、燃焼初期では酸化被膜は主に高温でも電気抵
抗の高いAl2O3（1000℃で9.1×105Ω・ｍ）と電気
抵抗の小さい（Fe、Cr）2O3（1000℃で0.4〜
0.8Ω・ｍ）とからなる。そして酸化被膜は高温
である程度の導電性があり炎電流感知センサーと
しての機能を果たすが、時間の経過と共に地金中
のAlが選択酸化されて（Fe、Cr）2O3と置換され、
ほとんどAl2O3となつて地金と炎間はほとんど絶
縁状態となり、炎電流検出感度が低下してセンサ
ー機能を果たさなくなる。
本発明の目的は、比較的安価で被加工性、耐酸
化性の優れたFe−Cr−Al系合金及びFe−Cr−Al
−Ｙ合金の高温で長時間加熱後の酸化被膜を導電
化することにより、炎電流検知能力を持続する炎
電流感知センサーを提供することにある。
本発明は公知の上記合金にTiを0.04〜0.50％含
有せしめた合金をフレームロツドとして使用した
炎電流感知センサーである。しかして本発明セン
サーのフレームロツドは上記公知の合金における
と同様、その酸化被膜はAl2O3を主成分として母
材を酸化から保護すると同時に、TiはTiO2（1000
℃で74.9Ω・ｍの低電気抵抗を有する）となつて
Al2O3被膜中に分散析出し、高温かつ長時間の酸
化加熱の後においても被膜を導電性に保持し炎電
流感知能力を保つのである。
本発明センサーのフレームロツドに使用する
Fe−Cr−Al−Ti合金、Fe−Cr−Al−Ｙ−Ti合
金の成分範囲は第１表の通りである。
The present invention relates to a flame current detection sensor used in a monitoring device for extinguishing a pilot burner of a combustion appliance, a fuel control device, and the like. Flame current detection sensors are used in oil fan heaters and the like to control fuel. The flame rod of this flame current detection sensor is repeatedly heated to a high temperature for a long time, so it
Materials with excellent oxidation resistance such as Fe-Cr-Al-Y alloy, nickel chromium alloy, and stainless steel are used, but in general Fe-Cr-Al, which is relatively inexpensive, has good workability, and has excellent oxidation resistance, is used. An alloy or a Fe-Cr-Al-Y alloy is used. In addition, flame rods for flame current detection sensors must be oxidation resistant and must not lose their detection ability even after a long period of time, so the oxide film that forms on the surface is required to be conductive at high temperatures. In the case of Fe-Cr-Al alloy and Fe-Cr-Al-Y alloy, in the early stage of combustion, the oxide film mainly contains Al 2 O 3 (9.1×10 5 Ω・m at 1000°C), which has high electrical resistance even at high temperatures, and electrical resistance. Low resistance (Fe, Cr) 2 O 3 (0.4~ at 1000℃
0.8Ω・m). The oxide film has a certain degree of conductivity at high temperatures and functions as a flame current sensor, but over time Al in the base metal is selectively oxidized and replaced with (Fe, Cr) 2 O 3 .
The metal becomes almost Al 2 O 3 and becomes almost insulated between the base metal and the flame, reducing the flame current detection sensitivity and making it impossible to function as a sensor. The purpose of the present invention is to provide a Fe-Cr-Al alloy that is relatively inexpensive and has excellent workability and oxidation resistance.
The object of the present invention is to provide a flame current sensing sensor that maintains flame current detection ability by making the oxide film of -Y alloy conductive after being heated at high temperature for a long time. The present invention is a flame current sensing sensor using, as a flame rod, a known alloy containing 0.04 to 0.50% Ti. However, the flame rod of the sensor of the present invention has an oxide film mainly composed of Al 2 O 3 to protect the base material from oxidation, as in the above-mentioned known alloys, and at the same time, Ti is composed of TiO 2 (1000
It has a low electrical resistance of 74.9Ω・m at ℃).
It is dispersed and precipitated in the Al 2 O 3 film, and maintains the film's conductivity and flame current sensing ability even after high-temperature and long-term oxidation heating. Used for frame rod of sensor of the present invention
The component ranges of the Fe-Cr-Al-Ti alloy and the Fe-Cr-Al-Y-Ti alloy are shown in Table 1.
【表】
第１図は、炎電流感知センサーの原理を示す図
である。実線の如くフレーム（炎）４を介した電
気回路において、炎４の大小により炎自体の電気
抵抗が変動する。この変動を電流検知器２で検出
し、燃料制御弁３にフイードバツクすることによ
り炎を一定にするものである。
第２図は、Si0.5％、Mn0.5％、Cr18％、Al3.0
％のFe−Cr−Al−Ｙ合金にTiを0.15％添加した
ものと無添加のものとについて、炎温度1000〜
1100℃で通算燃焼時間200時間経過後の炎電流特
性を比較した結果を示す図である。横軸は点火後
の経過時間、縦軸は電流値である。
安定基準とは、使用初期の点火後炎電流が一定
の炎電流値に達するまでの時間である。
従来のFe−Cr−Al−Ｙ合金（Ti無添加）ａの
場合、初期は安定基準内で安定時の炎電流値に達
するが、200時間経過後は第２図の如く安定時の
炎電流値に達する時間が安定基準を大幅に越えて
しまう。一方、Fe−Cr−Al−Ｙ合金に0.15％の
Tiを添加した本発明合金Ａの場合は、200時間経
過後も初期特性のままであり、500時間経過後も
変化はみられなかつた。
Fe−Cr−Al合金についても上記Fe−Cr−Al−
Ｙ合金とほぼ同様の結果が得られた。
以上述べたように、Tiはフレームロツドの表
面に生成された酸化被膜中に介在して、該被膜に
導電性を与えるために必要な元素である。しか
し、その含有量が0.5％を越えると酸化増量が急
激に増加し、ロツドの酸化消耗を促進することと
なる。一方、0.03％程度以下では、添加効果、つ
まり酸化被膜への導電性付与効果が低下し、ロツ
ドとしての実用性能を満足しなくなる。
次にTi含有量の限定理由について説明する。
第３図は、0.5％Si、0.5％Mn、18％Cr、３％
Alをほぼ一定としＣ、Ti含有量を変化させて、
大気中で1000℃×200時間の燃焼試験を行つた場
合の酸化増量の関係を示す。この図よりＣ及び
Tiの増加と共に酸化量は増えることがわかる。
特にTiが0.5％を越えるとＣの増加に伴い酸化量
が急激に増加し耐酸化性が低下する。
また第２表は第２図と同一条件下でのTi含有
量と酸化被膜の導電性の評価を行つたものであ
る。
評価は、安定時の炎電流値に達するまでの時間
が30秒を越えるものを不良とした。[Table] FIG. 1 is a diagram showing the principle of a flame current detection sensor. In an electric circuit via a flame 4 as shown by a solid line, the electrical resistance of the flame itself varies depending on the size of the flame 4. This fluctuation is detected by the current detector 2 and fed back to the fuel control valve 3 to keep the flame constant. Figure 2 shows Si0.5%, Mn0.5%, Cr18%, Al3.0
% Fe-Cr-Al-Y alloy with and without 0.15% Ti added, flame temperature 1000~
FIG. 3 is a diagram showing the results of comparing flame current characteristics after a total combustion time of 200 hours at 1100°C. The horizontal axis is the elapsed time after ignition, and the vertical axis is the current value. The stability criterion is the time required for the flame current after ignition to reach a certain flame current value at the initial stage of use. In the case of the conventional Fe-Cr-Al-Y alloy (without Ti addition) a, initially the flame current reaches a stable flame current value within the stability criteria, but after 200 hours the stable flame current value decreases as shown in Figure 2. The time it takes to reach this value greatly exceeds the stability criterion. On the other hand, 0.15% of Fe-Cr-Al-Y alloy
In the case of alloy A of the present invention to which Ti was added, the initial properties remained the same even after 200 hours, and no changes were observed even after 500 hours. Regarding the Fe-Cr-Al alloy, the Fe-Cr-Al-
Almost the same results as the Y alloy were obtained. As mentioned above, Ti is an element necessary for intervening in the oxide film formed on the surface of the flame rod and imparting conductivity to the film. However, if the content exceeds 0.5%, the weight gain due to oxidation will rapidly increase, which will accelerate the oxidative wear and tear of the rod. On the other hand, if it is less than about 0.03%, the effect of addition, that is, the effect of imparting conductivity to the oxide film, decreases, and the practical performance as a rod is not satisfied. Next, the reason for limiting the Ti content will be explained. Figure 3 shows 0.5%Si, 0.5%Mn, 18%Cr, 3%
By keeping Al almost constant and varying the C and Ti contents,
The relationship between oxidation and weight gain when a combustion test is conducted at 1000°C for 200 hours in the atmosphere is shown. From this figure, C and
It can be seen that the amount of oxidation increases as Ti increases.
In particular, when Ti exceeds 0.5%, the amount of oxidation increases rapidly as C increases, resulting in a decrease in oxidation resistance. Table 2 shows the evaluation of Ti content and conductivity of the oxide film under the same conditions as in FIG. In the evaluation, those that took more than 30 seconds to reach the stable flame current value were judged as poor.
【表】
第２表よりTi含有量は0.04％程度以上必要であ
ることがわかる。したがつて本発明ではTi含有
量を0.04〜0.50％とした。
Ti以外の成分は公知のFe−Cr−Al及びFe−Cr
−Al−Ｙ合金の成分範囲である。
以上述べたように本発明は、比較的安価でかつ
被加工性の良好なFe−Cr−Al及びFe−Cr−Al−
Ｙ系合金にTiを0.04〜0.50％含有させたフレーム
ロツドを用いたことにより、耐酸化性が良好で長
時間安定して初期と同様に炎電流の検出が可能な
炎電流感知センサーが提供できるようになつたも
のである。[Table] From Table 2, it can be seen that the Ti content is required to be approximately 0.04% or more. Therefore, in the present invention, the Ti content is set to 0.04 to 0.50%. Components other than Ti are known Fe-Cr-Al and Fe-Cr.
-Al-Y alloy component range. As described above, the present invention provides Fe-Cr-Al and Fe-Cr-Al- which are relatively inexpensive and have good workability.
By using a flame rod made of a Y-based alloy containing 0.04 to 0.50% Ti, we are able to provide a flame current detection sensor that has good oxidation resistance, is stable for a long time, and can detect flame current in the same way as the initial one. It has become.
第１図は炎電流感知センサーの原理及び燃料制
御系統を示す図、第２図は、Fe−Cr−Al−Ｙ合
金にTi0.15％添加したものＡと、無添加のものａ
との炎電流特性の比較結果を示す図、第３図は
Ｃ、Ti量と酸化増量との関係を示す図である。
１：フレームロツド、２：電流検出器、３：燃
料制御バルブ、４：フレーム（炎）。
Figure 1 shows the principle of the flame current detection sensor and the fuel control system. Figure 2 shows Fe-Cr-Al-Y alloy A with 0.15% Ti added and a without Ti addition.
FIG. 3 is a diagram showing the relationship between C and Ti contents and oxidation weight gain. 1: Flame rod, 2: Current detector, 3: Fuel control valve, 4: Flame.
Claims (1)
生成される酸化被膜が高温で小さい電気抵抗とな
るように、重量％でTiを0.04〜0.50％含有せしめ
たFe−Cr−Al系合金またはFe−Cr−Al−Ｙ系合
金よりなるフレームロツドを備えたことを特徴と
する炎電流感知センサー。1 Fe-Cr-Al alloy or Fe-Cr-Al alloy containing 0.04 to 0.50% Ti by weight so that it has oxidation resistance and the oxide film formed on the surface by combustion has low electrical resistance at high temperatures. A flame current detection sensor characterized by having a flame rod made of a Cr-Al-Y alloy.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16233382A JPS5952747A (en) | 1982-09-20 | 1982-09-20 | Flame current detecting sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16233382A JPS5952747A (en) | 1982-09-20 | 1982-09-20 | Flame current detecting sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5952747A JPS5952747A (en) | 1984-03-27 |
| JPH0315696B2 true JPH0315696B2 (en) | 1991-03-01 |
Family
ID=15752549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16233382A Granted JPS5952747A (en) | 1982-09-20 | 1982-09-20 | Flame current detecting sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5952747A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60253962A (en) * | 1984-05-31 | 1985-12-14 | Riken Corp | Metallic electrode for flame sensor |
| JPS61176847A (en) * | 1985-01-31 | 1986-08-08 | Riken Corp | Metallic electrode for flame sensor |
| JP6533407B2 (en) | 2015-03-31 | 2019-06-19 | Ｊｏｙｓｏｎ Ｓａｆｅｔｙ Ｓｙｓｔｅｍｓ Ｊａｐａｎ株式会社 | Gas pressure actuator |
-
1982
- 1982-09-20 JP JP16233382A patent/JPS5952747A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5952747A (en) | 1984-03-27 |
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