ISSN Online: 2377-424X
International Heat Transfer Conference 12
Model for Heat Transfer in a Float Glass Annealing Lehr
Resumo
Sandia National Laboratories has been working under the sponsorship of DOE Office of Industrial Technology
to investigate and improve the control and operation of annealing lehrs used in the production of float glass. This
paper presents a fully coupled 3-dimensional model of heat transfer in a float glass annealing lehr that is
designed to execute rapidly on a small computer workstation so that it may be used by process engineers to
determine optimum set points for lehr operation. The model includes heat conduction and advection in the
moving glass ribbon as well as the semitransparent nature of radiative transfer in the glass. The model also
accounts for the mass flow of air and heat transfer in the cooling ducts and surface-to-surface radiative exchange
between the exterior walls of the ducts and the glass ribbon. Results from the model show the effects of
operating conditions on the glass temperature in a typical lehr and illustrates the use of mathematical modeling
to improve design, operation, and control. The model executes rapidly enough on a small computer workstation
that it may also be suitable for use in real-time model-based control.