Abstract: Fluid permeable candle filter comprising a self supporting tube a filter layer and a filter layer. The self supporting tube comprises ceramic oxide fibers and silicate ceramic oxide bonding phase.

Abstract: Fluid permeable filter material comprising a self supporting fluid permeable wall and a fluid permeable filter layer. The self supporting wall comprises ceramic oxide fibers, ceramic oxide particles, and silicate ceramic oxide bonding phase. The filter layer comprises non-woven ceramic oxide fibers and silicate ceramic oxide bonding phase.

Abstract: A rigid acoustic insulator panel for use as a sound insulator is disclosed. The panel is composed of a rigid matrix formed of randomly oriented, fused silica fibers having fiber diameters predominantly in the range between 0.5 and 2 .mu.m. The matrix has a three-dimensionally continuous network of open, intercommunicating voids, and a density of between about 2 and 6 lb/ft.sup.3. In one embodiment, the panel has greater flow resistance characteristics, progressing from a sound-absorbing side of the matrix to the opposite panel side. Also disclosed is a method of preparing the panel.

Abstract: An acoustic structure for use as a sound insulator in a jet engine is disclosed. The structure, which is carried in a sound-absorbing compartment of the engine, includes a framework and an acoustical insulation material disposed within the framework. The material is composed of a rigid matrix of randomly oriented, fused silica fibers having fiber diameters predominantly in the range 2-8 .mu.m, a three-dimensionally continuous network of open, intercommunicating voids, a flow resistivity between about 10-200K rayls/m, and a density of between about 2 and 8 lb/ft3. Also disclosed are a clad acoustical structure for sound attenuation in a jet engine, where operational temperatures exceed current jet engine designs, and a method of attenuating jet engine noise.