的特点是：热电极丝熔点高（3300℃），蒸气压低，极易氧化；在非氧化性气氛中化学稳定性好。 Tungsten-rhenium thermocouples are characterized by a high melting point of the hot electrode wire (3300 ° C), low vapor pressure, and easy oxidation, and good chemical stability in a non-oxidizing atmosphere. Large electromotive force and high sensitivity, the main thing is cheap.
The anti-oxidation problem of tungsten-rhenium thermocouples has always been a topic of concern to scholars at home and abroad, and is committed to research and solution. Our company has adopted the international advanced manufacturing process and successfully developed the assembled high temperature and high pressure tungsten rhenium thermocouple. The temperature range of this product is 0 ～ 1800 ℃, which is widely used in metallurgy, coking, chemical furnaces, heat treatment, glass, etc. Industry, it has the advantages of high accuracy, low price, stable performance, and is not restricted by the working environment atmosphere. It is an ideal product to replace platinum and rhodium thermocouples. The tungsten-rhenium thermocouple produced by our company has been widely used in many units, and its performance has reached the level of similar foreign products. Its technical indicators are as follows:
1. Indexing number: W-Re3 / 25, W-Re5 / 26
2. Temperature measurement range: 0 ～ 1800 ℃
3. Temperature measurement accuracy: <± 1% t; <± 0.5% t
4. Time constant: ≥180 s
5. Insulation resistance:> 5MΩ
6. Specifications: 300, 500, 750, 1000, 1100 (mm)
Tungsten-rhenium molten steel rapid temperature measurement thermocouple is specially designed for measuring the temperature of molten steel, molten iron and other metal melts. It has the advantages of small size, fast thermal response, high accuracy, and low price. Its technical indicators are as follows:
1. Maximum temperature measurement temperature: 1800 ℃
2.Temperature measurement accuracy: ≤ 0.5%
3.Insulation resistance: ≥30 MΩ
4.Measurement rate: ≥98%
5. Response time: <5 s
At present, the tungsten-rhenium thermocouples produced by our company are divided into three categories:
The first type is a fine ceramic protection tube. The specifications of the ceramic tube are: diameter of Ф8, Ф10, Ф12, Ф14, Ф16, and length of 300 ~ 1100mm. This type of thermocouple can be long-term in any atmosphere without being restricted by the working environment For use, the temperature measurement range is 0 ~ 1800 ° C. Another type is pure molybdenum protection tube. Molybdenum tube and tungsten tube specifications are: diameter Ф6, Ф8, Ф10mm, length 500 ~ 700mm, this type of thermocouple can only For long-term work in an environment protected by reducing or inert gas, molybdenum tubes are best used for a long time at a temperature below 1800 ° C, and the short-term use temperature can reach 2000 ° C;
Another type is tungsten protection tube. As for tungsten tube, it can work at 2100 ℃ for a long time, but it is difficult to process and it is very expensive.
Please choose the thermocouple suitable for you according to our parameters.
At present, when measuring temperatures above 1600 ° C, non-contact methods are often used. However, the error of this method is relatively large. If the contact method is used, the real temperature can be accurately measured. Among high-temperature thermocouples, precious metal thermocouples are expensive and the highest temperature can only be below 1800 ° C. Tungsten-rhenium thermocouples not only have high temperature measurement limits, but also good stability. Therefore, tungsten-rhenium thermocouples are used in metallurgy, building materials, and aerospace , Aviation and nuclear energy industries are widely used. China is rich in tungsten resources. Tungsten-rhenium thermocouples are cheap and can partially replace precious metal thermocouples (platinum-rhodium thermocouples). It is a promising temperature measurement material in the field of high temperature testing.
Its maximum operating temperature can reach 2800 ° C. However, when it is higher than 2300 ° C, the data is scattered. Therefore, the best use temperature is around 2000 ° C.
极易氧化，适于在惰性或干燥氢气中使用，或用致密的保护管使其与氧隔绝才能使用。 Tungsten-rhenium thermocouples are extremely susceptible to oxidation and are suitable for use in inert or dry hydrogen, or they can be isolated from oxygen with a dense protective tube. Can not be used in carbon-containing atmosphere (such as in a hydrocarbon-containing atmosphere, the temperature exceeds 1000 ℃ will be corroded). Tungsten or tungsten thorium is easy to form stable carbides in a carbon-containing atmosphere, which reduces its sensitivity and causes brittle fracture. In the presence of hydrogen, it will accelerate carbonization.
Tungsten-rhenium thermocouple is a high-temperature thermocouple developed in the 1960s. It is the best performing thermocouple among industrial thermocouples that can measure temperatures above 1800 ° C. It has a high melting point of thermal electrode materials and thermal stability. Good, large thermo-electromotive force, high sensitivity (high thermo-electromotive force rate), stable thermoelectric properties, good linear correlation between thermo-electromotive force and temperature, cheap price, etc. It is widely used in metallurgy, heat treatment, petrochemicals, glass, cement clinker, Temperature measurement in industries such as materials.
The temperature measurement range of tungsten-rhenium thermocouple is generally 0 ～ 2300 ℃, and the best temperature measurement range is 1300 ～ 2000 ℃. The long-term use temperature can reach 2400 ° C, and the short-term use temperature can reach 3000 ° C (but the data is more discrete when it is higher than 2300 ° C). Tungsten thorium thermocouple wire is easy to oxidize, suitable for use in vacuum, inert gas or reducing gas environment, but can not be used in carbon-containing atmosphere (tungsten or tungsten thorium is easy to form stable carbides in carbon-containing atmosphere, thereby reducing tungsten thorium The thermocouple wire's temperature sensitivity can cause brittle fracture, and the presence of hydrogen can aggravate this carbonization). The use of a special material protective sleeve to protect the hot electrode wire makes the thermocouple suitable for more temperature measurement environments.
保护管种类有：再结晶碳化硅管（1650℃以下）、MoSi2管（可在某些腐蚀性气氛中使用，1650℃以下）、高纯氧化铝管（1800℃以下）、氧化锆管（2000℃以下）、氧化镁陶瓷管、金属陶瓷管、钼管（1800℃以下）、钨管（2300℃以下）、钽管（2300℃以下）等等，绝缘管有高纯氧化铝管、BeO管、MgO管、BN管等。 Tungsten-rhenium thermocouple protection tube types are: recrystallized silicon carbide tube (below 1650 ° C), MoSi2 tube (can be used in some corrosive atmospheres, below 1650 ° C), high-purity alumina tube (below 1800 ° C), oxidation Zirconium tube (below 2000 ° C), magnesia ceramic tube, cermet tube, molybdenum tube (below 1800 ° C), tungsten tube (below 2300 ° C), tantalum tube (below 2300 ° C), etc. The insulation tube has high-purity alumina Tube, BeO tube, MgO tube, BN tube, etc.