EVALUATION OF BUBBLE REMOVING PERFORMANCE IN A TV GLASS FURNACE - PART-1 - MATHEMATICAL FORMULATION

The bubble evolution and dissolution process in a glass furnace is an extremely complicated physico-chemical phenomenon. Most of the huge nu mber of bubbles, generated in molten glass during the decomposition of the glass batch, are removed during the trajectory from the charging end to the forming section, but some remain in final products. On the basis of the two mechanisms, flotation and absorption, in the bubble r emoving process, a numerical simulator was developed to evaluate the i nfluence of first, glass and batch composition, including refining age nts, second, geometrical tank design and third, furnace operating cond itions upon the bubble quality in products. In particular, the simulat or enabled the estimation of the effect of refining gases which are ca used by decomposition of the refining agents. Furthermore, an index wa s devised to synthetically assess the numbers of bubbles in final prod ucts. In part 1, the principles of the model which composes the simula tor are described in mathematical formulation. The basic equations wit h boundary conditions and calculation procedures for thermal flow of m olten glass, gas concentration in glass melt and gas evolvement from t he refining agents are presented. The calculation strategy of the bubb le removing process is also described.