Insulation system

Abstract

An all metal, low conductivity, high performance and relatively lightweight, composite structure, in the form of an insulation blanket is operably disposed to be exposed to a high temperature zone, e.g., a high temperature fluid, or on a supporting surface exposed to high temperature. The composite includes two metal skin members spaced from each other by a metallic member functioning as a spacing member. The spacing member is preferably deformed to contact the spaced skin sheets at spaced positions, the space between the skin sheets forming a fluid space which defines a zone of substantially reduced heat transfer by convection. When deformed, the spacing member, or an array of spacers, also provides an elongated path for conduction of heat, and defines a plurality of cavities of limited volume forming stagnant gas pockets. The skin sheets may be perforated to vent the cavities and to provide expansion space for absorbing thermal growth by the metal components of the composite. The spacing member also operates as a shield against the transfer of heat by radiation with the effect that the composite has a heat transfer coefficient substantially dictated by the thermal conductivity of the fluid in the space between the skin members. Use of metal components, principally of commercially available materials, permits fabrication of composites having various shapes and structural strengths, e.g., vibration, compaction, fatigue, etc., good chemical stability and easily repaired. Various different forms and alternate arrangements are described.