Thermally insulated tubular component prodn. - by internally flame-spray coating ceramic shell and casting around metal outer casing

摘要

Thermally insulated tubular component is produced by pressing an insulation. layer (14), spraying the internal surface with a high thermal resistant coating (12) and finally encasing inside an outer casing (16). The pressed insultation layer (14) is made up of shells (22,24) separable along the tube axis and fitted with tons and groove type joints (26,28). The layer (14) is made by pressing together a powder mixture of micro-porous SiO2, ceramic fibres, sliming agent and inorganic wetting agent. The flame sprayed layer is made of a Ni-Cr-Al coating. The halfs of the shell are stuck together before being surrounded by a casing of grey cast iron or Al in a casting mould. ADVANTAGE: The production method is cost effective and the finished product is thermally stable.