High temperature duct insulator and method of making same

Abstract

Abstract THIS IS A REFLECTIVE AIR GAP INSULATOR FOR HIGH TEMPERATURE DUCTS IN AIRCRAFT. AN ANNULAR AIR GAP IS DEFINED BETWEEN THE DUCT TO BE INSULATED AND A REFLECTIVE LAMINATE INSULATING SLEEVE CONSISTING OF EXTREMELY THIN ALUMINUM FOIL AND A LIGHTWEIGHT RESIN IMPREGNATED GLASS CLOTH. RIGIDIZING OF THE THIN LAMINATE IS BEST ACHIEVED BY A PATTERN OF IMPRESSIONS FORMED INTO THE FOIL AND THE OVERLYING RESIN IMPREGNATED FABRIC. LONGITUDINALLY OF THE DUCT SYSTEM, SPACED OFFSET MEMBERS ARE MOUNTED WITHIN THE ANNULAR SPACE TO MAINTAIN THE INSULATOR AND DUCT IN COAXIAL ALIGNMENT IN ORDER TO DEFINE THE AIR GAP FOR INSULATION. FOR STRAIGHT DUCT SECTIONS, CYLINDRICAL INSULATING SLEEVES WITH ONE LONGITUDINALLY JOINT ARE EMPLOYED. FOR Y''S, T''S AND OTHER IRREGULAR SECTIONS OF DUCT, HALF SHELL SECTIONS OF INSULATOR ARE EMPLOYED WITH A PAIR OF OPPOSITE LONGITUDINAL JOINTS. THE INSULATOR IS LAID UP ON A TOOL SURFACE INCLUDING ANY PREFERRED FORM OF RIGIDIZING PATTERN, WHICH RECEIVES FIRST THE FOIL AND THEN THE RESIN IMPREGNATED CLOTH. THE LAMIINTO INTIMATE, SMOOTH, UNBROKEN AND CONTINUOUS ASSOCIATION WITH THE RIGIDIZING PATTERN OF THE MANDREL AND OF THE OVERLYING CLOTH ONTO THE FOIL AND RIGIDIZING PATTERN FORMED ON THE FOIL. THE WARP AND WOOF OR OTHER PATTERN OF THE CLOTH ARE ALSO INTIMATELY IMPRESSED INTO THE FOIL. WHILE STILL SO PRESSED, THE ASSEMBLY IS CURED AT AN ELEVATED TEMPERATURE. A HIGH TEMPERATURE THERMOSETTING RESIN, SUCH AS PHENOLIC, IS PREFERRED, ALTHOUGH OTHERS MAY BE UTILIZED. THIS RESIN IS PREFERABLY BLACK PIGMENTED TO IMPROVE EMISSIVITY OF HEAT.

Inventors

• 👤 John F Peyton
• 👤 Juan Gonzalez Jr
• 👤 Robert B Trelease

Bibliographic Details