Thermal protections of exhaust systems
12.02.2018
The thermal isolations are in fact ceramic materials largely used when producing airplane engines and turbines. They can be successfully applied in case of exhaust systems, turbocompressors and other similar parts, where there is a need to reduce the heat transfer for improving the overall performance of the vehicle.
Excessive heat transfer from the exhaust systems to other parts of a car will affect not only its overall working level, but also different other components damaging them.
The thermal isolations have the main advantage that they can keep the heat within the exhaust systems, they reduce the temperature under the cowling and they keep the thermal energy within the eliminated gas, therefore improving the thermodynamic efficiency of the turbocompressors. This generates an extra power and improved reliability of the vehicle.
The thermal isolations can be easily applied with the MK74 equipment from Metallisation. The gun can be either manually or automatically operated.
For high accurate applications the thermal isolations can be plasma sprayed, so that the layers of the coverage become more dens and more compact.
Applying procedure
Surface preparation
- The exhaust system has to be previously cleaned. All dust and oil remains are to be removed. This can be done using any accredited industrial solvent. Usually blasting is needed for assuring that the paint will dry to a solid, adherent protective coating.
- The SA3 cleaning level is to be obtained through blasting, according to the Swedish standards into force.
Spraying of thermal isolations
- Applying thermal isolations has to be done as soon as possible after cleaning is finished. This way eventual extra depreciations that might appear during working breaks can be avoided.
- The equipment has to be set the producer specifies in case of applying thermal isolations
- The surface to be covered will be initially cleaned with a vacuum system for eliminating all dust that might remain after blasting.
- The gun will have to be perpendicularly placed onto the surface for assuring a constant and uniform application of the ceramic material.
- It is recommended to maintain the layer thickness as indicated by the producer and the norms into force.
Spraying parameters
|
Material |
Nozzle |
Disc No |
Spraying distance |
Air capsule |
Air pressure |
Oxy pressure |
Gas pressure |
Gas |
Oxy |
Layer’s thickness |
|
99627 99636 99815 |
M |
S |
175-225 mm |
STD |
10/20 |
12 |
30 |
5.0 |
6.5 |
50-75 ?m |
|
Ceramica |
C |
4 |
75 mm |
propagator |
40 |
13 |
24 |
4.0 |
6.0 |
125-250 ?m |
Basically it is better to avoid interrupting the process, from the preparation phase till complete spraying.
Finishing works
There are no finishing works needed. If a special color is wished for the exhaust system, the ceramic material to be applied has to be chosen in the proper shade.
