3 results
Search Results
Now showing 1 - 3 of 3
- ItemLow Pressure evaporation from boron containing glass melts by the transpiration method(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2004) Dacko, Dawid; Wilsmann, Wolfgang; Conradt, ReinhardGlass melting is a well-established process, but it does not seem to be well understood under low-pressure conditions. Melting under low pressure has been suggested as a potential support of the refining process. This makes sense only if the evaporation form the glass melt is kept within acceptable limits. Α transpiration apparatus equipped for operation at low pressure, termed low pressure transpiration method, was used to investigate the evaporation from boron containing glass melts. We obtained information on the weight loss as a function of temperature, time, and pressure. We investigated an alkali borosilicate glass with acomposition in mol % of: 79SiO₂,7 Na₂O, 10 B₂O₃, 3 AI₂O₃, 1 minor constituents. At the beginning of glass melting, the evaporation mechanism was detected as surface controlled. Later, a diffusion controlled stationary behaviour was observed. The ratio of sodium oxide to boron oxide in the evaporated gas as determined by chemical analysis ranged from 1.25 to 1.4.
- ItemOn the relation between the crystalline and glassy State in multi-component oxide Systems(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2003) Conradt, Reinhard[no abstract available]
- ItemThermodynamics of glass melts and thermo-chemistry of glass forming batches(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2004) Conradt, ReinhardThe paper deals with the thermodynamics of glass melts and glass forming batches. In a first step, an improved approach to the heat capacities of multi-component glass melts by the combination of a thermochemical model and the Adam-Gibbs equation is presented. Then, the heat demand of dolomite decomposition is reinvestigated. Finally, a proposition is made for the modelling of the batch-to-melt reaction path, yielding Information on both calcoric and rheological properties.