| abstract |
Hollow glass microspheres (17) made from a low heat conductivity glass composition containing a high vacuum and a thin metal coating (20) deposited on the inner wall surface of the microspheres. The hollow glass microspheres (17) are used to make superior insulation materials in the construction of highly efficient solar energy collectors (29), (43). The hollow glass microspheres (17) are made by forming a liquid film of molten glass across a coaxial blowing nozzle (5), applying a metal vapor blowing gas (10) at a positive pressure on the inner surface of the glass film to blow the film and form an elongated cylinder shaped liquid film (12) of molten glass. A transverse jet (13) is used to direct an inert entraining fluid (14) over and around the blowing nozzle (5) at an angle to the axis of the blowing nozzle. The entraining fluid (14) as it passes over and around the blowing nozzle (5) fluid dynamically induces a pulsating or fluctuating pressure field at the opposite side of the blowing nozzle to form a spherical shape (17). |