Optimization of conditioning devices in the glass industry

Abstract

The considerations concerning velocity distribution of the glass melt in conditioning deviees, dependent on temperature distribution, are made for circular cross-sections. An analogous application of the results to rectangular cross-sections is possible. There are limits for the cooling performanee for a given channel design whieh cannot be exceeded simply by further lowering of the margin temperature or by using a stronger cooling outside. Α strong cooling can cause the danger of devitrification and thermal reboil. These problems can be avoided by mathematical simulations and appropriate measures derived from them. Calculations of electric current density show that there exist local maxima at the intake port above and below the vertical tube and at the left and right side of the entrance area of the plunger cell. It is advantageous to increase the platinum wall thickness in these areas. As a result of optimization a better operation and high thermal homogeneity at the hollow glass forming is possible together with reduced gob mass fluctuations down to 0.5 to 0.1 %. In the same way with homogeneous glass it is possible to reduce markedly the fluctuations of diameter and thickness in the case of tubing.