Four/ 4 Bores Alumina Tube for Thermocouple Protection and Multi-Channel Gas Flow in High-Temperature Furnaces

4 Bore Alumina Ceramic Tube Applications

• Laboratory Furnace

  ✅ Key Advantages

  1. Multi-Zone Temperature Monitoring
  Supports up to 4 thermocouple wires in one tube, enabling simultaneous measurement across multiple furnace zones.

  2. Contamination-Free Atmosphere
  ≥99.7% Al₂O₃ purity prevents trace metal diffusion, ensuring clean test environments for sensitive material analysis.

  3. Precision Fit with Furnace Ports
  Outer diameter tolerance within ±0.2mm ensures leak-free integration with standard lab furnace flanges.

  ✅ Problem Solved

  In a materials science lab conducting thermal gradient experiments, inconsistent readings occurred due to separate single-bore tubes misaligned in the furnace. Replacing them with a single 4-bore alumina tube enabled synchronized multi-point temperature tracking at 1600°C. This improved data consistency by 28% and reduced setup time by 40%, while eliminating cross-contamination between thermocouple wires.

• Gas Analysis System

  ✅ Key Advantages

  1. Independent Multi-Gas Channelling
  Four isolated bores allow simultaneous transport of up to 4 gas types without cross-interference.

  2. Corrosion Resistance in Reactive Environments
  Maintains structural integrity in H₂, CO, and SO₂ atmospheres up to 1600°C with no surface degradation.

  3. Smooth Bore Finish for Laminar Flow
  Internal surface roughness ≤ Ra 0.8μm ensures stable flow rate and accurate gas sampling.

  ✅ Problem Solved
  
  In a petrochemical plant’s emissions monitoring system, previous single-channel quartz tubes caused gas mixing and inconsistent readings. Switching to a 4-bore alumina tube enabled isolated sampling of four gas streams at 1450°C. This reduced cross-contamination errors by 92% and improved analyser calibration stability, cutting recalibration frequency from weekly to monthly.

• Heating Element Insulation

  ✅ Key Advantages

  1. Thermal Cycling Durability
  Withstands >1000 heating-cooling cycles between 200°C and 1500°C without microcracking.

  2. Low Thermal Expansion
  CTE of ~8.0 × 10⁻⁶/K minimizes stress on embedded heating wires during rapid temperature shifts.

  3. Multi-Wire Isolation in Compact Form
  Four internal channels allow parallel heating wire routing in a single tube, reducing system footprint.

  ✅Problem Solved
  
  In a compact industrial heater design, repeated thermal cycling caused cracking in standard ceramic insulators, leading to wire exposure and failure. Replacing them with 4-bore alumina tubes reduced failure rate by 85% over 6 months. The low expansion coefficient preserved wire alignment, and the multi-channel layout simplified internal wiring, cutting assembly time by 30%.

4 Bore Alumina Tube Usage Instructions

• Install

  1. Insert thermocouple wires or gas lines into each bore.
  2. Ensure proper sealing at both ends using ceramic caps or high-temperature sealants.
  3. Avoid mechanical stress during installation to prevent cracking.

• Store

  1. Store in a dry, vibration-free environment.
  2. Avoid stacking heavy items on top of the tubes.

• Clean

  1. Clean with isopropyl alcohol or deionized water.
  2. Avoid using metal brushes or abrasive tools.

• Common Mistakes

  1. Over-tightening clamps may cause microcracks.
  2. Rapid thermal shock (>300°C/min) may lead to fracture.
  3. Using in reducing atmospheres may degrade alumina over time.

Alumina Four Bores Tube FAQ

1. Q: Can I get a custom bore layout?
   A: Yes, we support custom bore numbers and spacing based on your drawing.
2. Q: What is the tolerance for inner and outer diameters?
   A: Standard tolerance is ±0.2mm for OD and ±0.1mm for ID.
3. Q: Can I use this tube for thermocouple protection?
   A: Yes, it is widely used for K, S, and B-type thermocouples.
4. Q: Is the tube glazed or unglazed?
   A: Standard finish is unglazed; polished or sandblasted options are available.
5. Q: Is this tube resistant to acids or alkalis?
   A: Alumina is chemically inert to most acids and alkalis except HF.
6. Q: Do you provide end caps or connectors?
   A: Yes, ceramic end caps and thermocouple connectors are available.

Alumina Four Bores Tube Reviews

• ⭐️⭐️⭐️⭐️⭐️
  “We use 4 bore alumina tubes in our lab furnaces. The dimensional accuracy is excellent, and delivery was fast.”
  -- R&D Manager, Germany

• ⭐️⭐️⭐️⭐️⭐️
  “Perfect for our gas analysis system. No leakage or contamination after 6 months of use.”
  -- Process Engineer, USA
• ⭐️⭐️⭐️⭐️⭐️
  “Custom 4-bore alumina tube was exactly as per our drawing. Great support from the engineering team.”
  --  Equipment Manufacturer, UK