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

simplify heat exchange technique through adaptive fluid beds and use of special silos. Tecogen
Inc. developed a fluidized bed batch preheater system for the Gas Research Institute in the
1980s. GRI then developed a raining bed batch/cullet preheater with a counter-flow heat
exchange system. Corning and Tecogen, supported by DOE, developed a raining bed batch and
cullet preheater in the late 1990s.
Since the mid 1980s, a number of batch, cullet or mixed batch plus cullet preheaters have been
introduced into glass manufacturing. Batch/cullet preheat temperatures of 482-932˚F (250–
500˚C) and energy savings of 12 to 18 percent have been realized. Worldwide, 13 batch/cullet
preheaters were installed, nine of these in Germany. European manufacturers have shown more
interest in preheating systems because they have been faced with higher energy costs. Batch and
cullet preheaters have been developed and installed by GEA/Interprojekt (direct preheating),
Zippe (indirect preheating), and Sorg (direct preheating). A combined direct cullet preheater and
electrostatic precipitator has been developed and installed by Edmeston. The Nienburger
process, in which exhaust gases and mixed agglomerated batch are in direct contact in a hopper,
has had the most success of all the preheating technologies tried. A combination preheater and
particulate capture variation to preheat loose batch-containing cullet is under development by
BOC Gases.
When evaluating a preheating technology for application to a glass furnace, a number of issues
must be considered.
• Does the unit preheat batch or cullet or mixed batch and cullet? Preheating of batch or cullet
separately reduces the economic benefits and complicates the material handling systems.
• Does the unit constrain the batch/cullet ratio? Glass makers need to be flexible with batch/cullet
ratios to meet constantly changing requirements of manufacturing.
• Does the unit increase pollution loading in exhaust gases, such as increased dust?
Manufacturers in few countries will allow emissions to increase above current levels.
• Does the unit treat exhaust gases to best standards for particulate and SOx emissions? If not, an
expensive post-process abatement device must be installed on the exhaust gas handling system.
IV.8.1. E-batch (BOC Gases, 2001)
Electrostatic batch preheating technology, or "E-Batch," uses the waste heat from furnace
exhaust gases for preheating batch and cullet to provide a simpler and lower-cost means of
melting glass than conventional air-fuel furnaces when they are fitted with air pollution control
systems. Developed by BOC Gases in 2001, the technology is unique in two ways. (1) It is
designed to be integrated with oxy-fuel-fired furnaces. (2) It incorporates exhaust gas cleaning to
the most stringent regulatory levels. The proprietary electrostatic mechanism (patent pending),
which retains batch in the unit with occurrence of virtually no batch entrainment, is the key
feature of E-Batch technology. (Alexander, Jeffrey C., “Electrostatic batch preheating
technology: E-Batch,” Ceramic Engineering and Science Proceedings, 22[1], 37-53 (2001))
In this system, particulate matter is precipitated from the furnace exhaust gases and deposited
onto the batch surface. As a result, cooled outlet gases are recirculated to temper the hot furnace
gases to about 1148 ˚ F (620 ˚ C). The E-Batch design has a low enough pressure drop to operate
under natural draft from a stack that is appropriately designed. Cleaned, cooled gases are
discharged into the atmosphere through the stack, in which the pressure is controlled by a
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