| 摘要 |
Hollow glass microspheres made from a low heat conductivity glass composition containing a high vacuum and a thin metal coating deposited on the inner wall surface of the microspheres are described. The hollow glass microspheres are used to make superior insulation materials in the construction of highly efficient solar energy collectors. The hollow glass microspheres are made by forming a liquid film of molten glass across a coaxial blowing nozzle, applying a metal vapor blowing gas at a positive pressure on the inner surface of the glass film to blow the film and form an elongated cylinder shaped liquid film of molten glass. A transverse jet is used to direct an inert entraining fluid over and around the blowing nozzle at an angle to the axis of the blowing nozzle. The entraining fluid as it passes over and around the blowing nozzle fluid dynamically induces a pulsating or fluctuating pressure field at the opposite or lee side of the blowing nozzle in the wake or shadow of the coaxial blowing nozzle. The continued movement of the entraining fluid over the elongated cylinder produces asymmetric fluid drag forces on the cylinder and closes and detaches the elongated cylinder from the coaxial blowing nozzle and the detached cylinder by the action of surface tension forms into a spherical shape. Quench nozzles are disposed below and on either side of the blowing nozzle and direct cooling fluid at and into contact with the molten glass microspheres to rapidly cool and solidify the molten glass to form a hard, smooth hollow glass microsphere and to cool and condense the metal vapor and to deposit the metal vapor on the inner wall surface of the microsphere as a thin reflective metal coating or transparent metal coating.
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