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Show Emphasis is given to the furnaces because approximately 80% of the energy consumed in glass manufacturing is in the melting part of the operation. Typical charts of container, flat and pressed and blown glass energy consumption distribution are included. Gas is the preferred energy source for the glass industry for many reasons. It is and has been the dominant fuel. As an example of its importance and standing the container segment achieved an energy effid.ency improvement of 20% during the 1977 to 1982 period. During this period gas consumption dropped only about 1.5%. For a period of time, electrical energy use increased through the use of boosting to obtain more output with a given size furnace and due to emission regulation restrictions. Recent cost increases of electricity com-pared to fossil fuels has reversed this trend. The following chart depicts the relationship of the various fuels to total fuel consumption for the container section. The flat glass has an even higher % of gas to total fuels used. Thermal efficiency of regenerative furnaces has increased from 19% to over 28% today. In some new well designed and managed furnaces, a thermal efficiency of over 40% can be achieved. To present a rather simplified picture of energy use and efficiency of the melting furnace, comparisons between theoretical and actual melting furnaces may be examined. The theoretical energy needed to melt batch is calculated at about 2.3 million BTUs per ton of glass. The actual rate ranges from the best at about 3.9 to levels of over 11 million BIUs per ton of glass pulled. The published average for container furnaces was 7.8 in 1980. Recent reviews indicate a consensus average of about 5.0 to 5.5 million BTUs for container furnaces. The amount of energy needed for flat glass furnaces is higher due to the necessity of higher quality or lower "seed" count of the glass. There have been significant reductions in energy consumption in recent years through improved and increased insulation, better refractory materials, process control and furnace design improvements. However, the difference between theoretical and actual energy consumption presents a continuing and current problem. PROBLEMS The problem, simply stated, is "HOW TO IMPROVE THE THER¥.AL EFFICIENCY OF GLASS MELTING FURNACES." There is a need for at least a 25% reduction of fuel or energy use in melting glass. Today's glass melting furnaces still resemble the 1860 Siemens design. The energy required to melt glass remains at twice the theoretical value and most simple and basic steps available are reported as having been taken by the industry's furnace engineers. 25 With energy representing between 17 to 20% of the cost of the product, improvements in the efficiency of fuel use are extremely important to the glass industry. EnviroI1lJl.ental regulations also present serious ane costly problems for users of fossil fuels in the temperatures required. NEEDS Because most of the available and known techniques have been applied with a serious remaining need for improved melting efficiencies, the technical representatives need a break through and further technology transfer. An advisory committee of the glass industry identified the research needs cf the gla~s industry to be as follows: 1. Heat transfer to the glass melt. Heat transfer studies of various firing techniques, the use of various port designs, the number and placement of fuel injectors, new glass furpace burners and the regulation of flames for various loads as well as flame type ancl shape 2. An advanced glass melting system that would provide fuel consumption l~vels of 3.2 million BTUs per ton of glass or less with lower pollutant emissions 3. The development and application of advanced materials for furnace construction 4. Oxygen enrichment of i~rnace combustion air for increased furnace production at costs less than electric boosting s. Demonstration projects of cogeneration and batch preheating to prove their viability ane economics CURRENT PROJECTS The following GRI projects to fill the needs of the glass industry are now underway: Improved Oxygen Separator Glass Batch Preheater Advanced Glass Melter Glass Furnace Nox Controls Each of these projects are directed to fill the needs expressed by the glass industry for more efficient operations. Perhaps the most exciting one is the advanced glass melter which may well advance us from the 1860 furnaces design to todays modern technical age. Further research is essential to maintain the viability of this mature and historically fascinating basic industry. |