Analysis of Gas-Fired Ceramic Radiant Tubes During Transient Heating: Part I—Thermal Transient Modeling

Abstract

Abstract Low profile thermocouples were used to measure the external transient temperature distributions on open-ended silicon carbide radiant tubes during cold-start heating. The measured tube and furnace temperatures were used with radiant exchange relationships for gray-diffuse surfaces and natural convection formulations to calculate quasi-static effective heat transfer coefficients along the length of the tubes. Finite-element analysis was then used with the effective heat transfer coefficients to calculate the transient temperature distribution throughout the tube. Results indicate relatively mild radial temperature distributions during the heating conditions studied and the applicability of the analysis to different tube geometries and burner systems.