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

A. Literature and Patent Review—Glass Technology
In developing the body of this report, the principal investigators began the process by accumulating and
reviewing a volume of background literature, primarily registered patents and technical articles and
papers found in a broad variety of publications from around the world. With this advantage, they then
began to interview the many industry professionals who provided the bulk of the input to this document.
Recognizing that this effort was probably unprecedented and would likely disappear if not preserved as a
permanent record, the principal investigators pulled the data together into an extensive table that provides
not only the title and source, but also, where appropriate, a chart indicating the relevance of each article,
paper or patent to one or more of the 22 focus areas in glass melting process.
Note: Many of the publications are available on a CD obtainable at cost from the GMIC. Contact to
obtain a copy.
Relevant literature on glass melting technology has been reviewed extensively for relevant concepts,
ideas, experiments, production methods and patents as a basis for this technical and economic assessment
of glass melting. More than 500 articles or abstracts and 325 patents were evaluated with regard to
technical and financial/economic concerns; and applications for relevance to innovations in glass melting
procedures.
The lead institution for the literature and patent search was the Scholes Library at Alfred University, Pat
LaCourse, technical librarian. Other participates in the search included Owens Corning Knowledge
Resource Center, Ohio; Thermex International, St. Petersburg, Russia; and Masamichi Wada Consulting,
Japan.
The literature and patents are classified into 22 categories that comprise the main concepts of importance
to the glass manufacturing process. Each of the major classifications of glass-melting technology in
today’s US glass industry is detailed below.
A.1. Glass quality improvement
Glass quality can be affected by impurities in raw materials or by inadequate batch preparation
(weighting, mixing, etc.). Furnace design and/or operation directly impact the glass quality, which is
defined by quantified values of physical properties, including color, seed/blister counts, and homogeneity.
Measurements taken by spectrophotometers can quantify the amount of light transmission throughout the
visible spectrum, and in turn give numeric representations of color. Gaseous inclusions are categorized
by size and location in production and are most typically quantified by the number of seeds and blisters
per unit of weight, or area. Chemical homogeneity can be measured by properties such as index of
refraction, temperature versus viscosity, coefficient of thermal expansion (contraction), or presence of
foreign matter (non-glass).
Glass melting has traditionally relied on a single melting chamber where the fusion process occurs
through heating of solids, dissolution of sand grain, and refining of gaseous inclusions. The quality of the
glass is determined by variables and compromises such as melting production rates, energy and
temperature reduction. Changes in a furnace configuration can favorably impact glass quality.
Evolutions in glass melting technology have greatly improved glass quality in recent decades by
increasing glass depth; upgrading refractories; improving combustion and heat transfer conditions;
implementing supplemental boosting, bubbling and stirring devices; and improving sensors,
instrumentation and process control.
180