Specialty Cellular Glass Products and Their Applications

Abstract

Cellular glass products are composed of hermetically-sealed cells containing gases which exhibit no extracellular diffusion. As such, these products are impermeable to liquids and gases. FOAMGLAS® blocks have long been used as fireproof thermal insulation, especially in low temperature applications where condensation and subsequent ice formation in insulation can cause significant reduction in insulating value.

Recently, specialty compositions have been developed in the borosilicate and boroaluminosilicate fields which exhibit a high degree of resistance to corrosion by aggressive chemicals as well. One product, sold as PENNGUARDTM block by Pennwalt Corporation, is used as a liner for chimneys where acid corrosion had previously caused substantial maintenance problems. The product is also used as an insulative, acid-resistant liner in numerous chemical processes. A more refractory foam called FOAMSID®12 insulation has been developed for use in extremely corrosive environments at elevated temperatures. One such field of application, the Alcoa Smelting Process, involves the use of molten salts which tend to impregnate materials which are porous to either salt vapors or to the liquid phase. Such impregnation of ordinary insulating materials causes a significant increase in heat transfer rates.

FOAMSID®-12 blocks, with their unique properties of light weight, high strength, impermeability, and low thermal conductivity offer an opportunity for industrial energy conservation which did not previously exist.