Temperature effects, even with small deviations from the natural regime for a particular environment, can harm some materials. This does not mean that all facilities must have appropriate protection, but in some technological areas, the presence of such protection is very important. For this, a heat shield is used, which forms some kind of insulation. Similar protective equipment is used in the professional fields of construction, and in production, as well as in everyday life.
How does a protective screen work?
As a rule, such screens are sheets, canvases or panels made of one material. Another thing is that this material itself is a modified base, which is obtained as a result of special production procedures. The most common are molybdenum and tungsten panels, which are characterized by high thermal stability. In improved versions, the heat shield may have a more complex device. Usually these are two sheets, which are separated by a gap with shells - special conical drums. This gap can also be filled with heat-protective chips. In some cases, powder from the samemolybdenum or tungsten. A structure is being formed that, according to the principle of operation, resembles plastic windows with a heat-insulating vacuum.
Application areas
The scope of such screens is very wide. If you do not take into account highly specialized and professional niches, then the most popular will be materials for cars, windows and baths. In the first case, a collector heat shield is used, which is a simple metal plate. This is a thin sheet that is usually fixed at four points between the manifold and the injector.
In the case of windows, the use of such screens is due to the desire to prevent the penetration of cold into the apartment in the winter. But in such systems, instead of powder, only air acts as a filler. A kind of pillow is created, providing an additional barrier against the cold. In other words, the thermal screen for window installation acts as an external insulator, which is effective in terms of saving space in the room itself. As for bath rooms, screens in them act to isolate specific objects that are sources of high temperatures. In particular, boilers and furnaces are protected by insulators, preventing dangerous thermal effects on nearby objects.
Key performance
Manufacturers strive to provide screens with three categories of operational properties. First of all, it is heat resistance. This quality not only means that hightemperature waves will not propagate beyond the barrier, but the risk of a destructive effect on the material itself, from which the heat shield is made and its filler, will also be eliminated. The second category represents mechanical protective properties, the presence of which ensures that the material will not be damaged, in addition to heat, by physical influences. For example, the same metal is resistant to accidental impacts and cuts. The third group of properties suggests the presence of other insulating properties. This can be, for example, a vapor barrier or a noise reduction function.
Protective screen specifications
When choosing a screen, you should mainly rely on the ability of the material to provide the above-mentioned heat resistance. The index of resistance to specific temperatures is a basic characteristic. So, tungsten panels can withstand temperatures of 3300 ° C, but as this indicator rises, the melting process begins. In turn, molybdenum copes with its function at a temperature of about 2610 ° C. But it should be remembered that peak temperatures are not at all a recommendation for use in such conditions. For example, manufacturers recommend using the same tungsten with molybdenum in conditions of 1300-1400 ° C. In addition, the choice also takes into account the dimensions that the heat shield has in a particular modification. They can be 100-150 cm in height, 50 cm in width, and the depth rarely exceeds 10 cm.
Varieties
Distinguish screens by design parameters, properties and applications. Moreover, all three criteria are mutually dependent and determine each other. For example, in providing windows for winter time, the most complex functional barrier in the device with a filler of tungsten can be used, while having the largest standard size. Specialized heat-resistant panels are used in the arrangement of boilers and furnace structures. On the other hand, the exhaust manifold heat shield is the simplest solution due to both the cramped mounting conditions and relatively modest heat loads.
Installation nuances
There are different installation methods, which are determined by the design of the screen itself and the installation conditions. The most reliable method provides for the initial installation of frames, on which the screen is subsequently mounted or fastened by means of brackets or self-tapping screws. At the same time, it is important to take into account the possibility of future dismantling of the structure. This is especially true of window thermal barriers, which are used only in winter. Again, a car heat shield provides the most affordable installation method. Typically, manufacturers provide holes in metal sheets and attach kits with hardware to fix the product. Another thing is that the installation site itself near the same collector must match the screen configuration.
Conclusion
In each case, when choosing a heat shield, considerindividual set of qualities. Moreover, resistance to thermal exposure is not always decisive. That is, modern materials and modified molybdenum and tungsten panels, even in budget versions, are able to cope with most domestic heat loads. Structural compliance with the installation site is much more important. For example, the thermal screen of windows must be designed not only to cover the area along the frames, but also to withstand a certain technological indent. The choice is even more difficult if it is necessary to tightly insulate the fireplace or stove. In such cases, they often resort to the services of manufacturing screens for special orders. The same, by the way, applies to the protective devices for automobile collectors.
