Glass Melting Technology: A Technical and Economic ... - OSTI

• The Year 1 go-no-go decision point criteria for continuing work will be design of the
pilot scale melter and procurement of equipment and components on schedule and
budget.
• The Year 2 decision point criteria for continuing work will be completion of pilot
scale testing with glass formulations from all four industry segments and analyses of
the product glasses.
Background
Any new melter must perform at least as well as refractory melt tanks by all technical,
cost, operability, and environmental criteria while providing tangible benefits to the glass
maker. A partial list of this daunting set of criteria, by category is shown below.
Criteria Category Specific Criteria
Technical High thermal efficiency, ability to make any glass formulation, can
handle needed temperatures and oxidation conditions, meet glass
quality requirements, integrates with batch handling and forming
processes
Cost Low melter cost, low maintenance cost, low energy cost,
inexpensive environmental regulation compliance
Operability Scalable from 25 to 700 ton/day, reliable, stable operation, easy to
idle, ability to start and stop, ease of access and repair, fast change
with glass formulation and color, no moving parts to be abraded by
the glass
Environmental Low air, water, and solid waste, recycle-friendly
The search for a lower-cost glass melter has led technologists to suggest a segmented
melting approach in which several stages are used to optimize the melting,
homogenization, and refining (bubble removal) instead of the current practice of using a
single, large tank melter. In this segmented approach, separately optimized stages for
high-intensity melting and rapid refining are expected to reduce total residence time by
80 percent or more. This approach to melting has come to be known as the Next
Generation Melting System (NGMS).
The project team has identified submerged combustion melting (SCM) as the ideal
melting and homogenization stage of NGMS. This is the only melting approach that
meets and exceeds all the performance characteristics of refractory tanks and also
provides large capital and energy savings to the glass industry. Submerged combustion
melting is a process for producing mineral melts in which fuel and oxidant are fired
directly into the bath of material being melted. The combustion gases bubble through the
bath, creating a high heat transfer rate to the bath material and turbulent mixing. Melted
material with a uniform product composition is drained from a tap near the bottom of the
bath. Batch handling systems can be simple and inexpensive because the melter is
tolerant of a wide range in batch and cullet size, can accept multiple feeds, and does not
require perfect feed blending.
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