VISUAL OBSERVATION OF FOAMING AT THE BATCH-MELT INTERFACE DURING MELTING OF SODA-LIME-SILICA GLASS

Abstract

One of the least understood phenomena related to the optimization of the batch-to-glass conversion in melters is the behavior of the primary foam layer that develops at the interface between the batch and melt. Although its structure and behavior are directly linked with the heat and mass transfer between the reacting batch and melt, until recently, the foam layer at the batch bottom has eluded direct measurement. In this work, we build on our previous research addressing the primary foam behavior using high-temperature in-situ visual observation, and analyze its behavior at the batch-melt interface during melting of representative container soda-lime-silica glass. We visualize the formation of primary foam and its coalescence and collapse, leading to the formation of gas cavity layer at the batch bottom. The unprecedent contrast and resolution of the images provides detailed information on the foam morphology during melting, and can help in future development of more realistic batch melting models.

Keywords

• batch melting; batch foaming; foam decay; visual observation