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

eduction costs could purchase excess reductions (credits) from other companies whose emissions were lower than
federal regulations require.
environmental stewardship: When businesses take the responsibility to eliminate, reduce, and monitor pollutants
that harm the health of the environment.
EVA (economic value added): The residual income that remains after subtracting the cost of all capital (debt and
equity) from after-tax profits. EVA = (r – c) capital where r = rate of return on capital, c = weighted average cost
of capital, and capital = capital employed at the beginning of the year.
fictive temperature: a synonym for glass transition temperature.
float glass: Flat glass that is produced by a continuous process in which molten glass is floated on a bath of molten
metal, commonly tin.
forehearth: A refractory-lined channel whose function is to receive glass from the melter, refiner, or distributor;
reduce the glass temperature to a desired level; and discharge it to a feeder mechanism for forming.
forming method: In glass manufacturing, the processing methods used to produce the finished product.
fusion (sand solution) process: The process of melting glass batch to form a more or less homogeneous mass. See
also batch.
gob: A drop of molten glass formed by the cutting of a stream of glass as it flows from the forehearth through a
feeder and into an orifice of variable diameter. The greater the diameter, the larger the gob. Gobs are fed into
forming machines to be molded into bottles or other glass objects.
heavy metals: A group of metals whose specific gravity is approximately 5.0 or higher. These metals (e.g., lead,
cadmium, beryllium) and their compounds are considered to be toxic and become health hazards at elevated levels.
hurdle rate: The required rate of return in a discounted cash flow analysis, above which an investment makes sense
and below which it does not. Also known as required rate of return.
KK BTU/ton: equals million BTU per short ton.
NPV (net present value): An analytical method used in evaluating investments whereby the net present value of all
cash outflows (such as the cost of the investment) and cash inflows (returns) is calculated using a given discount
rate, usually a required rate of return. An investment is acceptable if the NPV is positive. In capital budgeting, the
discount rate is called the hurdle rate and is usually equal to the incremental cost of capital.
NOx: Nitrogen oxides. During the glass production process, air emissions such as nitrogen oxides are generated.
The U.S. Federal Clean Air Act limits the level of NOx and other pollutants that glass plants can generate.
oxy-fuel fired: Replacing combustion air with oxygen (>90% purity) in the firing process to reduce both energy
consumption and pollution.
pelletizing: The process of forming the glass batch into pellets to reduce dust emissions. See also briquetting.
preheater: Any device used to heat the batch and/or cullet material before it is charged into the furnace. See also
preheating and batch.
preheating: To subject the batch and or cullet material to a heat treatment prior to charging into the furnace. See
also preheater.
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