Refractory Lining Construction Method for Car-Type Heating Furnace

Car-type heating furnaces are widely used in heat treatment, forging, and metallurgical industries. A critical component of their performance and durability is the refractory lining, which includes refractory bricks and ceramic fiber modules. This article explains the materials selection and step-by-step installation methods for the refractory lining of car-type furnaces, based on practical experience and industrial standards.

Types of Refractory Materials for Car-Type Furnaces

For General Heating Furnaces:

• High alumina bricks
• Fireclay bricks
• Diatomite bricks, calcium silicate boards, or refractory fiber insulation boards
• High alumina refractory castables
• Polycrystalline mullite fiber products

For Heat Treatment Furnaces:

• Fireclay bricks
• Diatomite bricks, calcium silicate boards, or refractory fiber insulation boards
• Refractory castables
• Ceramic fiber blankets
• Ceramic fiber modules

Pre-Construction Checklist

Before starting the refractory lining installation, the following components must be checked for dimensional accuracy:

1. Rails and Foundation

• Track elevation and gauge
• Embedded steel plate position
• Furnace centerline alignment

2. Steel Structure

• Column installation and verticality
• Parallelism and perpendicularity of wall plates
• Burner brick elevation and burner port dimensions

3. Car Frame

• Track alignment with car centerline
• Flatness and elevation of car surface
• Position and height of sealing system

Only after verifying all the above elements can refractory material construction begin.

How to Install Refractory Bricks in Car-Type Furnace

Brickwork should follow these key principles:

• Use compatible refractory mortar with the bricks.
• Avoid through joints; ensure joints are fully filled with mortar.
• Control brick joint thickness precisely.
• Leave expansion joints every 2.5 meters, with 5–10 mm per meter.
• Use side-laying method (116 mm thick) for car surface bricks.
• At flue connections, use dry straight joints without mortar.
• For castables, follow the recommended casting procedure strictly.

Ceramic Fiber Lining Construction Methods

Car-type furnaces often use ceramic fiber lining for better insulation and energy efficiency. Below are the most commonly used fiber installation methods:

1. Anchored Folded Ceramic Fiber Modules

This is the most popular method for the roof and walls of car-type furnaces. Each module includes a folded blanket, pre-embedded anchors, binding strap, and protective plate.

Installation Steps:

1. Mark anchor bolt positions on furnace shell and weld them.
2. Lay two layers of ceramic fiber blanket (total 50 mm thick) and fix with clips.
3. Use guide rods to align and install modules onto anchor bolts.
4. Fasten using special wrench and nuts.
5. Remove plastic wrapping and shaping aids after installation.
6. If needed, apply curing agent and high-temperature coating to the surface.

2. A-Frame Folded Module Installation

This method is suitable for furnace walls. It uses A-shaped stainless steel brackets and rods to hold fiber modules without embedded anchors.

Steps:

1. Weld A-frames on furnace wall steel plates.
2. Lay a base layer of fiber blanket.
3. Insert and compress the folded modules between the A-frames.
4. Tie the modules together with rods.
5. Add compensation layers and remove ties after installation.

3. Layered Ceramic Fiber Lining

This is one of the earliest fiber installation methods, now mainly used in low-temperature car furnaces and flue linings.

Steps:

1. Weld anchor bolts to the steel surface.
2. Lay fiber blankets or felts in staggered layers.
3. Compress to the required thickness and secure with clamp plates.

4. Burner Brick Assembly with Fiber Protection

Burner bricks endure high temperatures and may crack. Install a refractory burner sleeve (brick or castable) with a 10–20 mm fiber-filled gap around the burner brick for protection.

5. Fiber Lining Above Furnace Door

The top area above the furnace door is prone to damage from heat and mechanical pressure. Use anchored fiber modules with dual-bolt fixation for better sealing and durability.

Why Proper Refractory Installation Matters

High-quality refractory lining improves:

• Thermal efficiency
• Energy savings
• Service life of the furnace
• Maintenance and repair frequency

By using the correct materials and proven installation techniques—especially modular ceramic fiber systems—car-type heating furnaces can operate more efficiently and safely.

Conclusion

If you are designing, building, or maintaining car-type heating furnaces, it is essential to choose the right refractory materials and follow best practices for lining construction. Whether using refractory bricks or advanced ceramic fiber modules, proper installation directly affects the furnace’s performance and cost-efficiency.

Need help choosing the right refractory solution? Contact our team of experts today.