Although we might think that the installation of insulation in an industrial furnace is a simple matter, the reality is that when it is carried out without the appropriate engineering studies, it is most likely that we will later encounter some common problems, such as:

  • Heat leaks that are generated by not having the necessary precautions to protect the areas where the material shrinks.

  • Degradation due to poor quality or poor choice of fiber.

  • Furnace roofs that partially detach or fall, resulting in heat leakage.


Article content:

Advantages of ceramic fiber over refractory brick
Various types of furnace insulation
Fiber installation methods
Insulation for special cases

Advantages of ceramic fiber over refractory brick


In the following section, we will describe the substantial benefits of using ceramic fiber insulation in your furnaces:

1. Avoiding thermal shock
When working with high temperatures of 1100°C (2010°F) and opening the furnace in operation, the thermal shock from cooling can cause refractory material to break or for fractures to appear, affecting its operation and significantly reducing its useful life.

With our ceramic insulation there is no danger when opening the furnace, this being especially useful when it comes to the operation of shuttle furnaces.

2. Optimized gas consumption
To heat refractory brick until the desired furnace temperature is achieved, a large amount of energy is required due to its higher density, unlike ceramic fiber which does not require as much energy in order to reach the desired temperature levels.

3. Faster installation on wide roofs
The installation of traditional refractory material in furnace roofs needs a considerable reinforcement in the structure to support the brick arch. This installation is faster with ceramic fiber thanks to its lightness and versatility.

4. Virtually maintenance free
Our ceramic insulation material is extremely resistant, hence any possible damage to the fiber will not affect production as it would in the case of refractory brick.

Various types of furnace insulation


At Nutec Bickley we review the required furnace operating temperature in order to select the correct fiber for the insulation and to determine the necessary thickness, which can range from 6 in to 12 in (15.25 cm to 30.5 cm) in three different grades, as follows:

  • LTS fiber insulation: for temperatures up to 1093°C (2000°F)

  • HPS fiber insulation: for temperatures up to 1316°C (2400°F)

  • HTZ fiber insulation: for temperatures up to 1425°C (2600°F)



Fiber installation methods


In the following section, we will talk about our various insulation techniques for furnace insulation:

1. Insulation with ceramic modules

This method is suitable for furnaces that will operate at temperatures between 500°C and 1100°C (930°F to 2010°F). We have different subdivisions according to the length of the module:

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  • Mini-modules – 12in (30.5cm) long
  • Standard modules – 48in (122cm) long
  • Jumbo modules – longer than Standard

In the case of heights up to 200in (508cm), we join one module with another to provide greater stability.

Advantages

  • Extremely easy to manipulate, and versatile given its diversity of sizes, especially with smaller modules.

  • Reduced risk of heat leaks.

 

2. Insulation with Macro-modules

Macro-modules comprise a single monolithic piece without joints, custom made to the size required by the user for the insulation of walls, roofs and doors in furnaces with operating temperatures greater than 1100°C (2010°F).

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Advantages

  • Ideal for very high temperatures where there is risk of heat leakage.

  • No risk of fractures thanks to secure anchorage with a rod in each layer, which prevents vibrations that damage the structure.

  • Extremely stable building element.

 

3. Jointless

Jointless is a Nutec patented component and is used in roofs that present greater exposure to leaks. It is manufactured in one piece to avoid any possible infiltration.

The installation of this system requires a thorough study to determine the optimal process, which if not followed can be very expensive and lead to leaks and production problems.

Advantages

  • Very useful for the gas exhaust area.

  • Ideal for very high temperatures.

  • Manufactured in one piece.

  • It can be fixed with both H-type and U-type anchors.

  • It can be type T or type L.

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4. Stack bond

This system consists of several stacked fiber blankets with cut-outs to enable fitting, and is specifically designed for the sealing of doors and the perimeter of furnace walls.

Advantages

  • Better compression due to several layers protecting the area.

  • Adjustable according to the dimensions required by the client.


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Insulation for special cases



5. Jointless II

This is the same as Jointless technology, but instead of the gas exhaust area it is used in the insulation of the furnace door.

It is important to consider that if the insulation is not well aligned and final adjustment is not made correctly, it may leak at the top and bottom.

Advantages

  • For high temperature furnaces.

  • One-piece module without risk of leaks.

  • Greater ease of construction, unlike the traditional stack bond insulation commonly used in furnace doors.

 

6. ‘Donut’ style vents

These vents are used to expel gases from the furnace to the environment by creating round or square holes in the fiber to allow gas to escape. This design helps avoid the need to use ducting or steelwork that would enlarge the furnace envelope.

Advantages

  • Space reduction due to reduced steelwork.

  • Economic method.

  • More space freed up in the client’s factory.

 

7. J-type seals

This design consists of a figure J with a bar in the middle that acts as a wall support, allowing the sealing of areas where there is no structural part that provides the mechanical strength required to seal the door.

Advantages

  • Provides a strong seal without leaks.

  • Ideal for areas where there is no structure to rely on.


At Nutec Bickley we are experts when it comes to understanding the behavior of ceramic fiber, so we use our experience to employ various techniques designed specifically to avoid operational failure. Contact us and tell us about your next project, where our expert advisors will be ready to assist you.

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