Ceramics-Silikáty 58 (4) 296-302 (2014)

MATHEMATICAL MODELING OF COLD CAP: EFFECT OF BUBBLING ON MELTING RATE

The rate of melting is a primary concern in the vitrification of radioactive wastes because it directly influences the life cycle of nuclear waste cleanup efforts. To increase glass melting performance, experimental and industrial all-electric waste glass melters employ various melt-rate enhancement techniques, the most prominent being the application of bubblers submerged into molten glass. This study investigates various ways in which bubbling affects melting rate in a waste glass melter. Using the recently developed cold cap model, we suggest that forced convection of molten glass, which increases the cold cap bottom temperature, is the main factor. Other effects, such as stirring the feed into molten glass or reducing the insulating effect of foaming, also play a role.

Keywords: Glass melting, Glass foaming, Waste vitrification, Cold cap, Bubbling