Geometric optics based analysis of radiation heat transfer in glass melting furnace foams

Abstract

The paper describes a simple, geometric optics-based model to analyze thermal radiation through glass foam layers that form on the surface of the glass melt in many industrial glass melting operations. The large value of radiation size parameters (>1000) characteristic of glass foams combined with an idealized foam morphology is used to derive recursive algebraic relations relating the effective reflectivity, transmissivity, and absorptivity of the foam to key parameters of gas bubble size, porosity, thickness, and glass melt absorption spectra. A sample of calculated results are presented to il-How to cite this article: Choudhary MK. Geometric optics based analysis of radiation heat transfer in glass melting furnace foams.

Effect of material properties on batch‐to‐glass conversion kinetics

“…At higher temperatures, thermal radiation plays a nonnegligible role. [51][52][53][54][55] Experimental determination of the effective thermal conductivity of primary foam is complicated because the rapid bursting and coalescing of bubbles increase the uncertainties. The effective thermal conductivity, 𝜆 ef f , and effective thermal diffusivity, 𝑎 ef f , of melter feeds is commonly determined using heat penetration experiments, which involve heating a feed sample in a crucible and recording temperature evolutions at multiple locations within the sample.…”

“…Thus, λ eff must account for the convective heat transfer in both the open‐porosity layer, where molten salts react with other components (both crystalline and amorphous), and in the primary foam layer, where vigorous foaming may occur. At higher temperatures, thermal radiation plays a nonnegligible role 51–55 . Experimental determination of the effective thermal conductivity of primary foam is complicated because the rapid bursting and coalescing of bubbles increase the uncertainties.…”