Determination of heat conductivity of waste glass feed and its applicability for modeling the batch‐to‐glass conversion

• Published in: Journal of the American Ceramic Society Vol. 100; no. 11; pp. 5096 - 5106
• Main Authors: Hujova, Miroslava, Pokorny, Richard, Klouzek, Jaroslav, Dixon, Derek R., Cutforth, Derek A., Lee, Seungmin, McCarthy, Benjamin P., Schweiger, Michael J., Kruger, Albert A., Hrma, Pavel
• Format: Journal Article
• Language: English
• Published: Columbus Wiley Subscription Services, Inc 01.11.2017; American Ceramic Society
• Subjects: Cold; Cold working; Computed tomography; Computer simulation; Conversion; foams; glassmelting; Heat conductivity; Heat transfer; Mathematical morphology; modeling/model; Slurries; Thermal conductivity
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.15052

The effective heat conductivity (λ) of reacting melter feed affects the heat transfer and conversion process in the cold cap, a layer of reacting feed floating on molten glass. A heat conductivity meter was used to measure λ of samples of a cold cap retrieved from a laboratory‐scale melter, loose dry powder feed samples, and samples cut from fast‐dried slurry blocks. These blocks were formed to simulate the feed conditions in the cold‐cap by rapidly evaporating water from feed slurry poured onto a 200°C surface. Our study indicates that the effective heat conductivity of the feed in the cold cap is significantly higher than that of loose dry powder feed, which is a result of the feed solidification during the water evaporation from the feed slurry. To assess the heat transfer at higher temperatures when feed turns into foam, we developed a theoretical model that predicts the foam heat conductivity based on morphology data from in‐situ X‐ray computed tomography. The implications for the mathematical modeling of the cold cap are discussed.