Method and apparatus for working molten glass
AssigneeSaint-Gobain Vitrage
InventorsMichel Zortea, Robert Noiret, Gerard Dossier
Life of this patent
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Abstract
The invention relates to working molten glass in tank furnaces for continuous production. According to the process of the invention, the vitrifiable material being brought first to the molten bath state in a zone upstream from the tank, and said bath then having access to the successive downstream zones allocated to the other phases of the process of working the glass through at least one tank portion comprising a section reduction of the type usually called a neck, there is generated at the upper level of the opening available to the glass by said neck a glass current directed from downstream to upstream of said neck. The invention proves to be especially advantageous for electric melting furnaces with large production capacity.
Claims42
In a continuous process for working glass in a tank furnace of a generally elongated shape having a plurality of compartments through which passes, in series, a molten glass bath, a first upstream compartment having a cover of a pulverulent vitrifiable material and a second compartment located between said first upstream compartment and a downstream compartment and having a reduced section compared thereto, wherein the vitrifiable pulverulent material is brought to a molten state in said first compartment and is transported to successive downstream compartments allocated to other phases of the glass working process and ultimately withdrawn from said tank furnace, the improvement which comprises generating a return current of molten glass directed from downstream to upstream in an upper portion of said second compartment to form a return current to said first upstream compartment, said return current being generated at least in part by an electric current applied to at least one electrode located in said reduced section second compartment.
A device for the continuous working of molten glass comprising:
- a tank furnace of a generally elongated shape having a plurality of compartments through which passes, in series, a molten glass bath;
- a first upstream compartment having a cover of pulverulent vitrifiable material;
- a second compartment located between said first upstream compartment and a downstream compartment, said second compartment having a reduced section compared to said upstream and downstream compartments and having no cover of pulverulent vitrifiable material, and means for generating in an upper portion of said second compartment a current of molten glass directed from downstream to upstream to form a return current to said upstream compartment, said means comprising at least one electrode located in said reduced section second compartment to which an electric current is applied.
A process for working glass in a tank furnace of a generally elongated shape having a plurality of compartments through which passes, in series, a molten glass bath, comprising:
- generating a current of molten glass directed from a first upstream compartment to a plurality of downstream compartments by forming a molten glass bath in said first compartment and by drawing said molten glass from a downstream compartment of said furnace, the first upstream compartment having a cover of pulverulent vitrifiable material which is distributed over the totality of the surface of said upstream portion, a second compartment being located between the first compartment and a third compartment, and having a reduced section compared to the first and third compartments,
- preventing entry of said pulverulent vitrifiable material into said second compartment by means of a partition that separates an area above said molten glass current and,
- generating a return current directed from downstream into said first upstream compartment by applying a current to at least one electrode located downstream of said partition.
A device for the continuous working of molten glass comprising:
- a tank furnace of a generally elongated shape having a plurality of compartments through which a molten glass bath passes from a first upstream compartment to a downstream compartment from which it is withdrawn;
- a first compartment located in an upstream portion of said tank furnace having a cover of pulverulent vitrifiable material which is distributed over the totality of the surface of said upstream portion;
- a second compartment located between said first compartment and a third compartment of said tank furnace, said second compartment having a reduced section compared to said first and third compartments;
- a partition means to prevent entry of said pulverulent vitrifiable material into said second compartment;
- and
- a plurality of electrodes spaced throughout said first and second compartments so that when an electric current is applied to said electrodes a current of molten glass is directed from downstream to upstream to form a return current of some of said glass to said first compartment.
Dependencies are inferred from the claim text.