Yield improvement for an industrial-oxy fuel fired glass furnace

Abstract

A glass prodn. plant had about 10.5% prodn. loss due to glass defects. The furnace was about 7() years old and produced soda-lime glass. TNO has improved the line yield by redn. of these glass defects. TNO investigated the prodn. facility and found pull variations which were not compensated well enough by energy corrections. By measuring the response of the melting tank at disturbances originating from pull variations and energy input, a black-box-model of the furnace was made. This model was used for an improved control system for the melting tank. Furthermore, the glass defects were studied in more detail and it was found that they originated from above glass level in the melting tank. With the use of the TNO-Glass Tank Model, the behavior of the temp. and the flow of the melt in the melting tank were studied and predicted the effect of a change in the process settings on the melting process. The main result was a change in current flow of the glass melt which resulted in a better soly. of the glass defects. Also a thorough anal. of selected historical data of the furnace was made, which showed a correlation between process settings and glass defects. This correlation was in agreement with lab. experience available at TNO on refractory corrosion by sodium vapors under oxy-fuel firing conditions. The empirical model developed by TNO to predict sodium evapn. and refractory corrosion were in good agreement with data obtained from prodn. By changing the process settings, the fast increasing corrosion was stopped and the amt. of the prodn. loss decreased from 10.5% to 5%. This successful cooperation between a glass prodn. plant and TNO showed that theor. knowledge of the glass prodn. and the refractory corrosion combined with measurements, historical data anal. and modeling can lead to improvement in case more complex mechanisms are responsible for prodn. losses. [on SciFinder (R)