Silica powders for powder evacuated thermal insulating panel and method

Patent · Tue Jan 02 04:00:00 EST 1996

OSTI ID:170444

Harris, M T; Basaran, O A; Kollie, T G; Weaver, F J

A powder evacuated thermal insulating panel using generally spherical and porous silica particles of a median size less than about 100 nanometers in diameter, a pour packing density of about 0.4 to 0.6 g/cm{sup 3} and an external surface area in the range of about 90 to 600 m{sup 2}/g is described. The silica powders are prepared by reacting a tetraalkyl silicate with ammonia and water in an alcohol solvent, distilling the solution after the reaction to remove the ammonia and recover the alcohol. The resulting aqueous slurry was dried, ball-milled, and dried again to provide the silica particles with defined internal and external porosity. The nanometer size and the large external surface area of the silica particles along with the internal and external porosity of the silica particles provide powder evacuated thermal insulating panels with significantly higher R-values than obtainable using previously known silica powders. 2 figs.

• Research Organization: Lockheed Martin Energy Syst Inc
• DOE Contract Number: AC05-84OR21400
• Assignee: Dept. of Energy, Washington, DC (United States)
• Patent Number(s): US 5,480,696/A/
• Application Number: PAN: 8-298,719
• OSTI ID: 170444
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
BULK DENSITY
CHEMICAL PREPARATION
DESIGN
LOW PRESSURE
MATERIALS
PARTICLE SIZE
R FACTORS
SILICON OXIDES
SPHERICAL CONFIGURATION
THERMAL INSULATION