Ceramic Fiber Module Insulation for Ring Tunnel Kilns

Product Overview: Ceramic Fiber Insulation for Ring Tunnel Kilns

China produces over 670 billion standard bricks annually, making it one of the world’s largest brick manufacturing countries. Traditional annular kilns have low capital investment, but are labor-intensive, energy-inefficient, and offer relatively low output. The evolution of tunnel kiln insulation in China has progressed through three key stages:

1. Dense refractory materials + lightweight insulation + red bricks
2. Lightweight refractory materials + ceramic fiber
3. Advanced ceramic fiber module systems made from lightweight energy-saving materials

When ceramic fiber modules are used in ring tunnel kilns, mobile tunnel kilns, or brick tunnel kilns, the system provides significant benefits: higher production capacity, lower fuel consumption, longer service life, improved automation, and better working conditions.

Kiln Structure Requirements and Insulation Material Selection

The kiln roof must:

• Withstand long-term high temperatures (especially in the firing zone)
• Be lightweight
• Provide effective thermal insulation
• Be tightly sealed to prevent air leakage
• Promote uniform internal airflow

Typical tunnel kilns include a preheating zone, firing zone, and cooling zone—usually measuring 90–130 meters in total length.

Recommended materials:

• Preheating and cooling zones (~650°C): 1050°C standard-grade ceramic fiber modules
• Firing zone (1000–1200°C): 1260°C standard-grade or 1350°C zirconia-alumina ceramic fiber modules

Use a composite structure combining ceramic fiber modules and layered ceramic fiber blankets to improve thermal efficiency, extend refractory life, and reduce cost. The layered blanket also serves as backup protection in the event of module damage.

Advantages of Using Ceramic Fiber Modules as Ring Tunnel Kiln Insulation

• Low Bulk Density: 75–95% lighter than firebricks or castables; reduces steel structure load and extends kiln life.
• Low Thermal Mass: 1/10 the heat storage of firebrick linings; reduces heat absorption and energy loss during cycling.
• Low Thermal Conductivity:
  • <0.10 W/m·K at 400°C
  • <0.15 W/m·K at 600°C
  • <0.25 W/m·K at 1000°C
• Quick Installation: Easy to operate, reduces construction time and labor costs.

Installation Process of Ceramic Fiber Modules in Ring Tunnel Kilns

1. Rust Removal: Clean furnace steel structure to meet welding standards.
2. Marking Layout: Use construction drawings to mark module layout and anchor bolt positions.
3. Welding Anchors: Weld bolts with protection to avoid thread damage and ensure quality.
4. Laying Blankets: Lay two offset layers of ceramic fiber blankets. Fix temporarily with clips on ceiling.
5. Installing Modules:
   • Tighten guide sleeves on anchor bolts.
   • Align module center hole with guide tube, push flush to wall, and fasten with nut using a socket tool.
6. Installing Compensation Blankets: Place same-grade blankets between module rows to compensate for thermal shrinkage. Use U-pins for ceiling fixation.
7. Final Adjustment: Inspect and align the full lining top to bottom.
8. Optional Coating: Apply protective surface coating to enhance service life.

Summary

Using ceramic fiber modules as insulation lining in ring tunnel kilns offers excellent thermal performance, faster heating, energy efficiency, and simplified construction. It is a modern solution for brick manufacturers aiming to improve operational performance and reduce long-term cost.