Glass melter

CMCs are used in the manufacture of preheaters and recuperators in heat recovery equipment. They are used for indirect heating and energy-intensive industrial internal processes such as glass melters, steel reheaters and aluminium remelters. 

The off-gas from melting of mixtures of salt cake with either basalt and B2O3 or sand and lime consists mainly of NO and CO2 from decomposition of nitrate, nitrite, and carbonate salts. The off-gas will also contain water vapor and, possibly, traces of SO2. Not unexpectedly, some radio-cesium also volatilizes when salt cake is converted to glass at 1100°-1200°C. Our laboratory-scale tests suggest, however, that of the order of 5%, or less, of the radio-cesium will volatilize when salt cake is converted to glass in a conventional continuous glass melter. 

Current development is directed toward a continuous rotary calciner directly feeding into a borosilicate glass melter with batchwise drawoff of the waste glass. 

Many scientists have attributed global warming and the greenhouse effect to increases in carbon dioxide in the atmosphere. Because all combustion-fired glass melters are fired with carbon-based fuels such as natural gas or oil, one of the products of combustion is C02. Obviously, the more one saves fuel, the more one reduces C02 emissions. As discussed previously, oxygen-based combustion can reduce fuel consumption by 5 to 45%. This directly relates to a corresponding C02 reduction of 5 to 45%. 

Comparison of Process Economics with Air and Oxygen for a 250 ton/day Glass Melter... 

Current issues on refractory monolithics include no-cement castables, self-flow and free-flow mixes [64], and special compositions such as spinel-based [65], placement techniques [66], new applications (i.e., crown superstructures for glass melters [67]), characterization [68, 69], and basic castables [70, 71]. Specialized publications have compiled and reproduced most of the most important topics [i.e, 72-74], which include the following ... 

Typical recuperative glass melter. (From Eleazer, P. B., and Hoke,... 

Assessment of Numerical Simulation of Industrial Glass Melter." Verre 1 no. 5 (1995) 9-13. 

Continuous control and monitoring of all process steps, in particular the waste feed stream, the thermal and chemical processes occurring in the glass melter, and the packaging of the final glass product. 

Heat tecovery equipment internals Air preheaters, recupeituots Any indirect healing uses enetgy-intensive industrial processes (e.g. aluminum temehns, steel leheaters, glass melters)... 

Figure 2. Glass temperature and glass melt flow example in a flat glass melter. Note the recirculation of the glass melt coming back from working end into the melter (by Glass Service).

Figure 8. Comparison between measured and calculated temperatures in the former Ford Nashville, TN, float glass melter, calculated by Glass Service.

Gullet Waste or broken glass softens readily in glass melters to bring batch particles together, thereby increasing batch reaction rates, often immensely. This batch material is referred to as cullet. There are many economic and environmental factors favoring use... 

Such fuel-fired continuous melters can be very large. For example, a soda-bme-silica float glass melter may contain as much as 2000 tons of molten glass and deliver it at a rate of 800 T/day. The top surface area of the glass in the melter could be more than 5000 Large... 

Types of oxide refractories used in glass melters are ... 

S. Matsuno, Y. Iso, H. Uchida, I. Oono, T. Fukui and T. Ooba. CFD modeling coupled with electric field analysis for Joule-heated glass melters. J. Power Energy Syst. 2 (1), 2008, 447. 

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