Field Test of Millimeter-Wave Waste Glass Melter Monitoring Technology for Viscosity and Salt-Layer Formation

摘要

The harsh, high temperature environment inside a joule heated waste glass melter is not an obstacle to millimeter-wave monitoring technology. This work has successfully established the basis for on-line viscosity monitoring and salt layer formation detection using millimeter-waves. Glass flow as related to viscosity measurement has been measured not only at one depth, but also through the whole depth cross-section of a melter demonstrating the potential for viscosity profile measurements inside the melt pool. Salt layer formation was detected without any contact with the melt by observing the large change in surface MMW emissivity of about 30% between the molten glass and salt. In addition, large MMW thermal emission fluctuations are shown to be a clear indicator of the start of molten salt accumulation giving the melter operator time to take corrective measures long before a continuous salt layer is formed. A minor investment in implementing the monitoring technologies demonstrated here and previously could result in large cost savings for the national nuclear waste vitrification effort.