Experimental procedures to simulate essential process steps in glass melting, by Marco Van KERSBERGEN (TNO)


“This presentation shows several different experimental methods, to investigate and simulate essential process step in industrial glass melting, on laboratory scale. These methods include:
- Heat penetration into batch blankets to measure the effective heat conduction (radiation and thermal conduction) or heat diffusivity of glass foming batch with and without cullet;
- Bubble growth and bubble ascension observations & measurements in glass melts, to measure the fining onset temperature or the effect of oxidation state and quantity of fining agent on temperature dependent bubble growth and bubble removal from silicate melts. The fining test facility can also be used to investigate physically driven fining processes: sub-atmospheric fining, helium enhanced fining or acoustic (ultrasonis) fining;
- Foaming behavior of batches during melting-in (primary foam) and during fining (secondary foam);
- Evolved gas analysis during melting-in and fining: the analysis of the gases released during melting and fining will provide important information on the reactions and reaction kinetics of decomposition reactions in the batch or decomposition of fining agents in the melt;
- Transpiration evaporation tests, to determine the kinetics of evaporation of volatile glass melt components (alkali, fluorides, boron components, sulfur, chlorides) and the effect of furnace atmosphere, contamination of the melt and temperature on evaporation rates and kind of evaporating species from multi-component glass melts.
- Corrosion tests for refractory materials exposed to typical glass furnace combustion gases or flue gases. These tests can be applied to test different candidate refractory materials for furnace crowns or regenerator checkers.
The results of these measurements can be used to optimize industrial glass melting processes or to supply important data (chemical activities, fining on-set temperature, foaming kinetics) for models that simulate the glass melting process and sub-models simulating fining, batch melting, foaming and evaporation.”

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