ES288151A1 - Improvements in glass-melting - Google Patents

Abstract

A method of melting glass or quartz in a furnace having a base outlet 3 for the molten glass or quartz, comprises supplying heat to the melt surface from burners 9 directed substantially horizontally above the melt surface and disposing raw materials for the melt in a thin annular layer on the melt surface, the inner periphery of said layer encircling but not covering said molten glass outlet and the outer periphery of said layer being spaced from the inner wall of the furnace. The burners 9 are offset from the vertical axis of the furnace, Fig. 2 (not shown), and hence impart a whirling motion to the combustion product gases 45. The raw materials are charged from a shaking gutter 35 through a tube 38 into the furnace, the said tube being positioned in a gas outlet 13 coaxially disposed above the molten glass outlet. The rising, whirling combustion gases exert an expanding effect on the free-falling glass-forming particles which are finally deposited on the melt surface in a thin annular layer or zone 31, Fig. 2, having an inner periphery surrounding the melt surface 33 above the molten glass outlet and an outer periphery spaced from the furnace wall. The to-be-melted or melted particles in said annular layer follow the trajectories 35, 36 and 37, enter the drawing cone 15, and are discharged to the drawing machine 21. The drawing cone <PICT:1041825/C1/1> comprises parts of molybdenum and is provided with a mandrel 17 and a tungsten heating element 23. The cone and coil are contained in an envelope 25 to which a supply of non-oxidizing gas is connected. As shown at 27, non-oxidizing gas is supplied to the bore of the being-drawn tube. The diameter of the annular layer or zone of the raw material may be maintained constant with varying particle size by adjusting the height A of the movable tube 38 above the melt surface.