2009

Treating Fibrous Insulation To Reduce Thermal Conductivity

A chemical treatment reduces the convective and radiative contributions to the effective thermal conductivity of porous fibrous thermal-insulation tile. The net effect of the treatment is to coat the surfaces of fibers with a mixture of transition-metal oxides (TMOs) without filling the pores. The TMO coats reduce the cross-sectional areas available for convection while absorbing and scattering thermal radiation in the pores, thereby rendering the tile largely opaque to thermal radiation.

The treatment involves a sol-gel process: A solution containing a mixture of transition-metal-oxide-precursor salts plus a gelling agent (e.g., tetraethy-lorthosilicate) is partially cured, then, before it visibly gels, is used to impregnate the tile. The solution in the tile is gelled, then dried, and then the tile is fired to convert the precursor salts to the desired mixed TMO phases. The amounts of the various TMOs ultimately incorporated into the tile can be tailored via the concentrations of salts in the solution, and the impregnation depth can be tailored via the viscosity of the solution and/or the volume of the solution relative to that of the tile. The amounts of the TMOs determine the absorption and scattering spectra.

This work was done by Alfred Zinn and Ryan Tarkanian of The Boeing Co. for Johnson Space Center.

Title to this invention, covered by U.S. Patent No. 7,198,839 B2, has been waived under the provisions of the National Aeronautics and Space Act {42 U.S.C. 2457 (f)}. Inquiries concerning licenses for its commercial development should be addressed to:

The Boeing Company
5301 Bolsa Ave,
Huntington Beach, CA 92647-2099

Refer to MSC-23394-1, volume and number of this NASA Tech Briefs issue, and the page number.

This Brief includes a Technical Support Package (TSP).

Treating Fibrous Insulation To Reduce Thermal Conductivity (reference MSC-23394-1) is currently available for download from the TSP library.

Please Login at the top of the page to download.

 

White Papers

Oscilloscope Fundamentals
Sponsored by Rohde and Schwarz A and D
Laser-Induced Damage to Large Core Optical Fiber by High Peak Power Laser
Sponsored by OFS
Introduction to Hypervisor Technology
Sponsored by Curtiss-Wright Controls Embedded Computing
4 Critical Factors: Deploying GigE Vision in Real-Time Industrial Imaging
Sponsored by Teledyne DALSA
R&S® SMB100A, NRP, FSW-K6, ZVL Radar Educational Videos
Sponsored by Rohde and Schwarz A and D
Testing Astronaut-Controlled Surface Robots from the International Space Station
Sponsored by HP

White Papers Sponsored By: