Process for producing molten glass, glass-melting furnace, process for producing glass products and apparatus for producing glass products
The present invention provides a process for producing a molten glass which can produce a molten glass having a good quality, a glass-melting furnace, a process for producing glass products and an apparatus for producing glass products. While an oxygen combustion burner 20 is rotated by a motor 38 , glass raw material particles (not shown) are dropped into a high-temperature gas phase atmosphere produced by a flame F of the oxygen combustion burner 20 , to be changed into liquid glass particles. By rotation of an outlet (nozzle) of the oxygen combustion burner 20 , the falling position of the liquid glass particles 26 , changes with time. Accordingly, generation of bubbles caused by continuous fall of the liquid glass particles in a particular position on a molten glass liquid surface is prevented. Accordingly, it is possible to produce a molten glass having a good quality with few bubbles.
1. A process for producing molten glass, which is a process of changing glass raw material particles into liquid glass particles in a gas phase atmosphere in a glass-melting furnace and accumulating the liquid glass particles in a bottom portion of the glass-melting furnace to obtain a molten glass liquid; the process comprising:
supplying the glass raw material particles downwardly from a furnace wall portion in an upper portion of the glass-melting furnace to let the particles pass through a gas phase portion formed by a heating means, to change the particles into liquid glass particles; and
changing with time the position of the gas phase portion in substantially horizontal direction and thereby changing with time the falling position of the liquid glass particles formed in the gas phase portion on the molten glass liquid surface.
2. The process for producing molten glass according to claim 1 , wherein the heating means is an oxygen combustion burner producing an oxygen combustion flame or a multi-phase arc plasma generation apparatus constituted by at least a pair of electrodes producing thermal plasma.
3. The process for producing molten glass according to claim 1 , which comprises moving the heating means in substantially horizontal direction.
4. The process for producing molten glass according to claim 1 , wherein the heating means is an oxygen combustion burner constituted by a combustion gas supply tube, an oxygen tube and a glass raw material particle supply tube, that are coaxially arranged; the process comprising moving the outlet of the oxygen combustion burner in substantially horizontal direction.
5. The process for producing molten glass according to claim 1 , which employs a plurality of heating means for forming gas phase portions at respective positions in the horizontal direction, and which comprises operating the heating means at different timings.
6. A process for producing glass products comprising a step of producing molten glass by the process for producing molten glass as defined in claim 1 , a step of forming the molten glass, and a step of annealing the formed glass.