What is a high-temperature insulation
High-temperature insulation is an insulation with maximum capacity, specifically designed for the use at extreme temperatures. It reduces the transfer of thermal energy emanating from hot components and thus protects surrounding components from high temperatures. As a result, high-temperature insulation not only increases the service life of surrounding components, but also reduces significant risks of various kinds.
Very high temperatures of over 1,000 °C often prevail in machines and vehicles with combustion engines or electric and hydrogen applications. The hot surfaces in the engine compartment give off heat quickly and pose an enormous safety risk to people and machinery, for which conventional thermal insulation systems do not provide sufficient insulation. High-temperature insulation reduces heat to an appropriate level, allowing not only safe start-up of the machine, but also a remarkable increase in efficiency as well as helping to meet strict emission guidelines.
Which industries are high-temperature insulations used in?
High-temperature insulations are used wherever high temperatures prevail and improper temperature management would pose a risk to people, machines, and the economy. In the event of a fire, the consequences weigh heavily. The engine compartment contains both flammable materials and extremely hot surfaces. If the two collide, a fire can result. Even if no human life is harmed, the economic consequences for the company are unpleasant.
As a result, more and more companies are opting for a high-quality high-temperature insulation to minimize fire risks, but also to benefit from the advantages of modern insulation. We, at tmax Group, have noticed for many years that the topics of noise and contact protection as well as increasing efficiency are of great importance and are explicitly requested by our customers. All these requirements can be implemented with modern insulation solutions and lead to the required results.
Railway
Marine
Power Sports
Construction
On-Highway
Agriculture
What properties should a high-temperature insulation have?
High-temperature insulation systems must be robust, durable, and efficient. To ensure this, all materials used must be of the highest quality and have very good insulating properties. Particularly important are optimal density and low heat-storage of the insulation material, as well as the flexible installation and snug fit of the entire insulation.
A good high-temperature insulation should have these properties:
- Application limit temperature: up to 1,200 °C
- Temperature reductions to a nonhazardous 220 °C or even to 60 °C if required
- Non combustible
- High mechanical strength
- Very high insulation value
- Optimal heat storage in the component to be insulated
- High vibration resistance
- Easy to assemble and disassemble, reusable
- Secure positioning and precise fit on the component to be insulated
- Splash-proof
Which requirements must a high-temperature insulation meet?
The requirements for high-temperature insulation are as varied and individual as the component to be insulated itself. Depending on the area of application, the following topics must be fulfilled:
Compliance with emission standards
Fire protection
Optimal contact protection
SOLAS compliance
Protection of surrounding components
Increase service life
Increase efficiency
Soundproofing
The requirements for high-temperature insulation are manifold. And they are all feasible.
Exhaust gas aftertreatment
Emissions directives are becoming increasingly stringent, meaning efficient exhaust gas aftertreatment is more relevant than ever. This depends on optimal temperature distribution throughout the exhaust tract. Because wherever heat is lost, there is an energy deficit that must be compensated elsewhere. Proper high-temperature insulation avoids energy losses and ensures that optimal temperatures prevail at all key points in the exhaust tract at all times, thus helping to comply with emission directives and exhaust gas standards.
Targeted temperature control prevents crystals from forming in the diffuser during urea injection, that would make exhaust gas cleaning less effective. In addition, it also improves light-off behavior and reduces energy and fuel consumption, allowing exhaust gas aftertreatment to work earlier and more reliably. This enables CO₂ savings and the achievement of better exhaust gas values.
Fire protection
Surface temperatures of up to 850 °C can occur in the engine compartment of machines, vehicles, and systems. These high temperatures pose a tremendous fire risk, as there are also highly flammable materials in the engine compartment, and a contact of the two can quickly cause a fire or explosion. Hydraulic oils and fuels ignite at temperatures as low as 250 °C. High-temperature insulations reduce surface temperatures in the engine compartment to a nonhazardous 220 °C to ensure effective fire protection in the event of a leak or deposit of heat-sensitive substances.
For high-temperature applications in the marine sector and on oil platforms, the UN convention SOLAS (Safety of Life at Sea) stipulates that no exposed component may exceed a surface temperature of over 220 °C. This and more can be guaranteed by a suitable high-temperature insulation.
Soundproofing
Engine noises are very loud and, in the long run, represent a high level of stress that is difficult to tolerate and can cause lasting health impairments and damages. That is why the legal requirements for sound insulation are also becoming increasingly stringent. In order to comply with these, sound-absorbing measures in the engine compartment are required in addition to thermal insulation.
However, the installation space in vehicles and machines is limited. Thermal and acoustic insulation must be accommodated in a confined space while meeting a variety of requirements. Good high-temperature insulation therefore combines direct thermal insulation with the principle of sound absorption, and thus reliably reduces disturbing noise without compromising the thermal and mechanical properties of the insulation or the engine performance.
How are high-temperature insulations built?
The right material is crucial for perfect high-temperature insulation. They usually consist of three components: An outer layer, the insulating material and an inner layer, which encase the component to be insulated and reduce hot surface temperatures and radiant heat. The exact structure and the materials used vary according to the technical requirements as well as legal specifications and individual customer wishes.
Metal insulation cladding
A metallic insulating cladding consists of three components in cassette design: the outer sheet, the insulating material made of glass or silicate fiber, and the inner sheet. It encases the component to be insulated and significantly reduces the hot surface temperatures typical for the engine compartment.
Textile Insulation
A textile insulation is made of an outer fabric (1), the insulating material (2) made of glass or silicate fiber (3) and an inner fabric (4). The outer fabric protects the insulation from dirt, splash water, oil, and other external influences, while the inner fabric is more temperature-resistant and lies directly on the hot component.
In addition, the textile insulation is supported by another vibration-resistant fabric to protect the insulation system from wear as well as to increase its service life.
Foil insulation
Foil insulation consists of two to three components. For example, there is integral insulation, which consists of an outer shell of stainless-steel foil and a molded fiber part made of insulating fiber (glass or silicate fiber) lying directly on the component to be insulated. Blankets, on the other hand, have both an outer and an inner shell made of stainless-steel foil, which protect the insulation material inside from damaging influences of all kinds.
Both forms of foil insulation are shaped using embossing and forming tools and ensure optimum high-temperature insulation thanks to their perfect, millimeter-precise fit. The materials and the thicknesses of the insulation insert are developed and combined according to the respective technical requirements.
If required, the insulation fiber mat can also be made hydrophobic becoming even more effective and durable, even with regular contact with dirt and splash water.
How does high-temperature insulation work?
High-temperature insulation reduces the passage of heat to a minimum. But how exactly does that work? The basic principle is simple. The lower the density of a body, the worse it functions as a heat conductor and the better it functions as an insulating material.
(High-temperature) insulation materials contain a lot of air in a small space, such as in Styrofoam or between the fibers of flax, rock and glass wool. In this way, the insulating material takes advantage of the physical property of air because air is a poor conductor of heat.
High-temperature insulation systems from tmax contain a glass fiber or silicate fiber mat, which serves as the insulating material. Different material thicknesses can be used to control the individual insulating effect.
What temperature reductions are possible?
It is not possible to make general statements about the temperature reductions that can be achieved with a high-temperature insulation. This is because the results depend on numerous factors, such as the parameters of the component to be insulated and its temperature, the ambient temperature, the insulating material and the material thickness.
The following data refer to a measurement of the insulating effects of tmax high-temperature insulations in different designs, based on the change in surface temperatures of an exhaust pipe. Measurements were taken on an exhaust pipe with a pipe diameter of 100 mm and wall thickness of t = 2.5 mm at an ambient temperature of 25 °C. Under these basic conditions, a temperature reduction of approx. 50 % upwards can be achieved with high-temperature insulation from 10 mm material thickness. With the appropriate insulation thickness, a reduction to a harmless 60 °C can even be achieved.
Calculation basis:
Pipe diameter: 100 mm
Wall thickness of exhaust pipe: t = 2.5 mm
Ambient temperature: 25 °C
| Isoliermaterial | Materialstärke | Oberflächentemperatur der Isolierung bei einer Abgastemperatur von 500 °C |
|---|---|---|
| Metallisch | 10 mm | 155 °C |
| 20 mm | 120 °C | |
| Folie | 10 mm | 255 °C |
| 20 mm | 190 °C | |
| Textile | 10 mm | 200 °C |
| 20 mm | 145 °C |
| Isoliermaterial | Materialstärke | Oberflächentemperatur der Isolierung bei einer Abgastemperatur von 750 °C |
|---|---|---|
| Metallisch | 10 mm | 250 °C |
| 20 mm | 200 °C | |
| Folie | 10 mm | 370 °C |
| 20 mm | 275 °C | |
| Textile | 10 mm | 290 °C |
| 20 mm | 220 °C |
| Isoliermaterial | Materialstärke | Oberflächentemperatur der Isolierung bei einer Abgastemperatur von 1.000 °C |
|---|---|---|
| Metallisch | 10 mm | 345 °C |
| 20 mm | 275 °C | |
| Folie | 10 mm | 470 °C |
| 20 mm | 360 °C | |
| Textile | 10 mm | 380 °C |
| 20 mm | 295 °C |
Disclaimer: The above information is based on our current knowledge of the products indicated and is given in good faith. The specifications do not have the meaning of property assurances.
| Materialstärke | 10mm | 15mm | 20mm | 25mm | 30mm |
|---|---|---|---|---|---|
| Temperaturreduktion | 49 – 69% | 58 – 74% | 62– 76% | 74 – 78% | 76 – 80% |
Conclusion: These are the advantages of high-temperature insulation
A reliant high-temperature insulation is an important addition for any type of heat source. Are components or machines properly insulated.
All the advantages of high-temperature insulation at a glance:
- Temperature reduction from over 1000 °C to as low as 60 °C, with the appropriate insulation thickness
- Effective fire protection due to low surface temperature
- Energy and cost savings due to energy conservation in the system
- Protection of surrounding components from the effects of heat
- Compliance with stringent Stage V/Tier 4 emissions standards
- Compliance with strict noise emissions of EU Regulation 540/2014
- Compliance with SOLAS guidelines
