Method for making refractory lined duct and duct formed thereby

Abstract

A refractory lined duct is provided having sheet metal tube lined with a ceramic fiber matrix bonded with binder material forming a tubular refractory liner of predetermined thickness and thermal characteristics. This duct has the refractory liner held in fixed, retained relationship with the tube solely by frictional forces and adhesive bonding by the binder material. A method for making of this duct is provided and includes the steps of vacuum-forming of an elongated refractory sleeve or tube from a slurry of ceramic fibers and binder materials onto a tubular forming die, inserting the sleeve while in a hydrated state into a sheet metal supporting tube of complemental shape and size such that adjacent surfaces of the tube and sleeve will be in contacting engagement and then drying the assembly to remove the water resulting in forming of a hard, solid structure refractory liner that is fixed in the tube solely through frictional forces and adhesive bonding by the binder materials. A modified duct formed by the same methods includes a composite refractory liner formed from a plurality of tubular liners that each have their own respective structural, physical and thermal characteristics.

Dependencies are inferred from the claim text.