Longitudinal permeability and gas flow measurement for ceramic paper medium in annulus of ceramic ferrule – Tubular steel system

摘要

The ceramic ferrule –ceramic paper insert in steel tubes provides corrosion and thermal protection in a wide range of industries and most notably sulfur recovery waste heat boilers.The tube-sheet,tube to tube-sheet weld connection and tube portion in the near tube-sheet water field would be vulnerable to corrosion from elevated temperatures without protection of the ceramic ferrule system.Key properties of ceramic paper,gas flow through the ceramic paper media,and heat transfer at the near tube sheet tube provide understanding of why and how this protection system works effectively.Heat and mass transfer characteristics for the ceramic paper are critical for describing how this system functions.Gas permeability and radiation transmittance for ceramic paper,critical but not well known properties,are measured and reported in this paper.Water side heat transfer limitations for the near tubesheet water field immediately downstream of the ferrule exit are assessed with respect to critical heat flux for nucleate boiling conditions at operating steam pressures.