The optimal parameters of bubble centrifuging in glass melts

Abstract

The mathematical model of a multicomponent bubble in a glass melt under the influence of gravitational and centrifugal fields has been applied in the model TV glass. The optimal fining conditions have been examined in a rotating cylinder with the aim of determining their general features. All of the dependences between the bubble-removal time and the rotational velocity showed the region of bubble removal by centrifuging at low cylinder rotational velocities and the region of complete bubble dissolution when the rotation was intensive. The low rotational velocities, characterised by the minimal bubble-centrifuging time, appeared to be suitable for industrial application. Consequently, the influence of temperature, pressure and glass-layer thickness on the value of the optimal rotational velocity and optimal fining time of small-critical bubbles has been investigated in detail in a glass melt containing fining agent. The significant role of temperature and minor role of pressure have been proved and the identical features of bubble removal have been identified in cylinders with different radii and filling by glass but with the same average thickness of the glass layer on the cylinder walls.