Explosion-proof high-temperature corundum thermocouple

Explosion-proof high-temperature corundum thermocouple

Explosion-proof high-temperature corundum thermocouple—a temperature sensor specially designed for ultra-high temperatures of 1600°C and flammable and explosive environments. The core uses Al₂O₃> 99.3% high-purity corundum protective tubes, resistant to rapid cold and heat, not prone to shattering, and suitable for long-term use under extreme conditions of 1600°C and short-term 1800°C. Paired with explosion-proof junction boxes (explosion-proof grade dII.BT4~dII.CT6), suitable for high-precision temperature measurement in hazardous locations such as petrochemical, metallurgy, glass kilns, and gasifiers.

1. Product Overview

Explosion-proof high-temperature corundum thermocouples are temperature measurement products that combine high-temperature resistant corundum protective tubes with explosion-proof junction boxes. Corundum tubes have extremely high purity (Al₂O₃≥99.3%), high temperature resistance, corrosion resistance, and excellent insulation properties; The explosion-proof junction box uses high-strength aluminum alloy die-casting, which seals internal sparks and arcs inside the cavity, preventing ignition of external explosive gases.

This product is widely used in:

• Petrochemicals: gasifiers, cracking furnaces, and high-temperature temperature measurement for reactors

• Metallurgical industry: temperature monitoring for high-temperature kilns and melting furnaces

• Glass/Ceramics: Kiln temperature control

• Power industry: boiler furnace temperature measurement

• Coal Chemical: Coal slurry gasifier (≥ 6.5MPa high-pressure condition)

2. Core Technical Parameters

3. Graduation Code Selection and Comparison

4. Product Features

1. Corundum protective tube—the preferred choice for high-temperature conditions

• Purity Al₂O₃≥99.3%, with excellent high temperature resistance, corrosion resistance, and excellent insulation properties

• It has good resistance to rapid cooling and heating, is not prone to bursting, and can adapt to frequent heating and cooling conditions

• Suitable for oxidizing, neutral, and inert atmospheres; not suitable for reducing atmospheres (may damage platinum rhodium couple filaments).

2. Explosion-proof junction box—safe and reliable

• High-strength aluminum alloy die-casting, wall thickness and mechanical strength meet national standards

• Explosion-proof mark Ex d II B/CT4~CT6, suitable for various explosive gas environments

• The rubber sealing ring has good thermal stability and an IP65 protection rating

3. Sturdy Structure—Suitable for Harsh Environments

• Optional single-gauge or double-tube structures enable redundant measurement

• Multiple installation methods: fixed threads, fixed flanges, movable flanges, etc

• Optional integrated temperature transmitter, outputs 4-20mA signal

4. Stable performance—long service life

• S/R/B Type Platinum-Rhodium Coupling Wire has strong oxidation resistance at high temperatures and good long-term stability

• In large-size gasifier applications, the required quantity per single tube can reach 140-180 pieces

• Petrochemical enterprise tender requirements: minimum service life under normal use ≥ 80 days

5. Model and specification description

Common model notation methods (refer to WRP series):

Model selection example: WRP-440 → S-type explosion-proof high-temperature corundum thermocouple, fixed flange installation, explosion-proof junction box

6. Key points for model selection

When purchasing, you need to clearly communicate the following key information to the manufacturer:

1. Graduation code and temperature measurement range: Confirm the maximum temperature. S/R/B type is suitable for above 1600°C, K/N type below 1300°C

2. Protective pipe material and diameter: Corundum pipe is the standard; for special corrosion conditions, silicon carbide or GH3039 can be selected

3. Explosion-proof rating: Choose dII.BT4 or dII.CT6 according to the explosion-proof zone

4. Installation method and specifications: flange or thread? Standards, pressure levels, and dimensions are available

5. Insertion depth: Accurately provides insertion depth (L = l1/l2, hot end/cold end)

6. Output signal: mV signal or 4-20mA output with transmitter

7. Certification requirements: explosion-proof certificate

7. Precautions for Use

1. Atmosphere limitations: Corundum tubes and platinum rhodium wires are not suitable for reducing atmospheres (such as hydrogen-containing gases, CO, etc.), as they can damage the components

2. Mechanical protection: Corundum tubes are brittle, so avoid collisions during installation and transportation

3. Regular calibration: After long-term use at high temperatures, accuracy may drift; periodic calibration is recommended

4. Wiring requirements: Compensation wires must be used (S/R/B types use corresponding compensation wires), with attention to polarity

5. Transmitter installation: When the ambient temperature is >70°C, the transmitter should be installed separately