Modeling for Automatic Control and Process Design

The effect of mathematical and physical modeling of processes has had relatively little effect on the glass industry. However, significant modeling results are available as indicated by a wide range of publications. In this paper, the published modeling work is grouped by area with discussion where appropriate. In addition, the major physical phenomena along a glass line are discussed with an assessment of the degree of difficulty in modeling them to an accuracy sufficient for either process control or process design. In this assessment the major assumptions and simplifications currently used in model derivative and specification are noted. It is concluded that many of the phenomenon are of such a complexity that models have not had sufficient accuracy for design purposes. One of these areas is the furnace with the main problems being the convection currents in the melt, the radiative heat transfer, and the melting physics and chemistry. Finally, the results of a questionnaire sent to glass industry technical personnel polling modeling efforts and results are discussed. An extensive bibliography of modeling work is a part of the paper.