INORGANIC FIBER BLOCK AND HEAT INSULATING STRUCTURE

摘要

PROBLEM TO BE SOLVED: To provide an inorganic fiber block and a heat insulating structure excellent in heat resistance and avoided from the depression of ceramic fibers caused by heat shrinkage and the erosion of a ceramic fiber part. SOLUTION: The inorganic fiber block is constituted of a laminate of a ceramic fiber blanket 3 and a polycrystalline alumina fiber blanket 2 and has characteristics of (a) the ceramic fiber blanket. The polycrystalline alumina fiber blankets are laminated and compressed, (b) each of the ceramic fiber blankets comprises ceramic fibers partially crystallized by heating, (c) the concentration of the Al2O3component of the ceramic fiber is 50 wt.% or above, (d) the Na concentration of the ceramic fiber is 600 ppm or below, (e) the compression ratio of the alumina fiber blanket is 1.2 times or above the ceramic fiber blanket, and (f) the bulk density of the ceramic fiber blanket in a block state is 1.1 times above the alumina fiber blanket. COPYRIGHT: (C)2006,JPO&NCIPI