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Foam glass - an ideal material for heat insulation pipelines

Post Time:May 29,2012Classify:Industry NewsView:127

In contrast to the "hot" lines, the temperature of the outer surface of which exceeds the average ambient temperature, the device thermal ´cold´ utilities (cold water piping and air conditioning systems) for a long time was a serious problem. This situation prevailed until the foam glass insulation products FOAMGLAS ®.Professionals are well aware that a high water vapor permeability of fibrous materials such as glass or mineral wool contributes to the diffusion of moisture under the influence of the partial pressure difference, which leads to the formation of condensation and moisture insulation, resulting in a sharp deterioration of its insulating properties. The probability of drying wet insulation of cold water supply line is practically zero. As a result of the accumulation of condensation, not only reduces the effectiveness of insulation, but there are additional problems, which include corrosion of equipment, damage to walls, ceilings, etc., caused by the leaking of the condensed moisture, and intense development of colonies of mold. To avoid this unpleasant phenomenon using fibrous materials on top of a layer of insulation is usually satisfied with a protective casing made of aluminum foil, which should act as a vapor barrier and prevent moisture diffusion into the thickness of mineral wool. But, in practice, even in a carefully assembled systems will eventually penetrate still moisture in the insulation, with all the (literally and figuratively) consequences.Studies have shown that the diffusion of water vapor is not necessarily the main cause of moisture in the insulation layer: another cause of air flow may be occurring due to the difference of air pressure.Let us consider the principle of action of this transport mechanism, known as "pump effect". Imagine a water pipe with cold water, isolated by means of a material with an open structure (such as mineral wool), which is created on top of the barrier layer parozaschitny aluminum foil. With proper installation of vapor control layer should prevent the penetration of moisture through diffusion. However, during system operation at low temperatures in the insulation layer is a pressure drop, and any defects in the aluminum coating allows moisture saturated air, seeking to balance the pressure to penetrate the insulation layer. This air flow brings moisture in the insulation, where it condenses when the temperature reaches the dew point. When the system temperature rises again, dry air leaves the insulation, and the next cycle, the temperature returns there is already saturated with moisture.Although foams and less permeable than the fibrous insulation materials, insulation, foam plastics (polyurethane, polystyrene, or penopoliizotsianurata) is also susceptible to moisture penetration. This means that most of them are protected from moisture (in the form of liquid or vapor) only to the extent that protection against evaporation can provide a vapor barrier. In addition, their flammability and propensity to release toxic gases during combustion makes a very unsafe use of materials of this group in the industrial, public and residential buildings, especially high-rise.The only non-combustible (Class NG) heat-insulating material having an absolute air and vapor resistance (resistance to water vapor diffusion μ = ∞), a foam glass FOAMGLAS ®. Foam glass FOAMGLAS ® is made from specially prepared high-aluminosilicate glass (sometimes as a raw material used windshields of cars or recycled foam glass waste is received as a result of mechanical treatment). All the ingredients are ground into powder, mixed with carbon and stainless steel forms are placed in special ovens. At high temperature the carbon is decomposed with a large release of CO2, and carbon dioxide to form a molten mass of multiple bubbles. Upon completion of the foaming power is obtained from a glass gas-filled bubbles with a lot of homogeneous structure. After annealing FOAMGLAS ® blocks are cut into pieces and treated to give them the form of plates, panels, shells, branches or segments of different types and sizes.Foam glass FOAMGLAS ® has several different brands with the spectrum of the thermal conductivity of 0.040 to 0.052 W / mK and the compressive strength from 35 to 160 t/m2. This wide range of values ​​to satisfy the specific requirements of any project. For example, FOAMGLAS ® T4 has a thermal conductivity of λ = 25 ° C 0.042 W / mK, considering the water vapor permeability is equal to zero, the estimated coefficient of thermal conductivity does not change its value and is equal to 25 ° C, λ = 0.042 W / mK, ultimate compressive strength of 60 t/m2.World experience of foam glass FOAMGLAS ® (available from 1942) unequivocally proves the profitability and long-term safety of using this material for insulation of cold water supply lines. FOAMGLAS ® extends the life of the entire pipeline system, and provides a reliable barrier against corrosion. It allows you to forget about the additional financial investments associated with maintenance, repair and premature replacement of system components, as well as increased energy levels, decreased due to the effectiveness of insulation. 29.05.2012, Foamglas / Steklosouz

Source: http://www.glassglobal.com/news/foam_glass_an_ideal_material_for_heat_insulation_pipelines-20332.htmlAuthor:

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