초록 ▼

The invention relates to an apparatus and a method for low-contamination melting of high-purity, aggressive and/or high-melting glass or glass-ceramic. According to the invention, for this purpose a melt is heated in a crucible or melting skull crucible by means of high-frequency radiation and is mi

The invention relates to an apparatus and a method for low-contamination melting of high-purity, aggressive and/or high-melting glass or glass-ceramic. According to the invention, for this purpose a melt is heated in a crucible or melting skull crucible by means of high-frequency radiation and is mixed or homogenized in the melting crucible. It is preferable for a gas nozzle, from which gas bubbles, e.g. oxygen bubbles (known as O2 bubbling), escape into the melt, to be provided at the base of the crucible. This alone makes it possible to achieve surprising multiple benefits in the melting skull crucible. Firstly, unmelted batch which drops into the melt in solid form, for example from above, is melted down more quickly as a result of more intensive mixing with the liquid fraction of the melt, secondly the temperature distribution in the melt is made more even, thirdly a uniform distribution or mixing of different glass constituents is achieved, and fourthly the redox state of the glass can be adjusted.

대표청구항 ▼

The invention claimed is: 1. An apparatus for melting glass or glass-ceramic, comprising: a crucible; an emitting device for emitting electromagnetic radiation into a melt in the crucible so that the melt is heated by the electromagnetic radiation; and a mixing device being assigned to the crucible

The invention claimed is: 1. An apparatus for melting glass or glass-ceramic, comprising: a crucible; an emitting device for emitting electromagnetic radiation into a melt in the crucible so that the melt is heated by the electromagnetic radiation; and a mixing device being assigned to the crucible so that the melt can be mixed and/or homogenized while it is still in the crucible, wherein the mixing device introduces a predefined flow in the melt. 2. The apparatus as claimed in claim 1, wherein the melt is set in internal motion by the mixing device. 3. The apparatus as claimed in claim 1, wherein the crucible comprises an outflow opening for the melt and a cooled bridge, the cooled bridge being immersed in the melt so that unmelted batch fractions are kept away from the outflow opening by the cooled bridge. 4. The apparatus as claimed in claim 1, further comprising an agitating device that is arranged in the crucible. 5. The apparatus as claimed in claim 1, further comprising a device for introducing gas or gas bubbles into the melt. 6. The apparatus as claimed in claim 1, further comprising one or more gas nozzles. 7. The apparatus as claimed in claim 6, wherein the one or more gas nozzles comprise one or more liquid-cooled nozzles. 8. The apparatus as claimed in claim 6, wherein the one or more gas nozzles are arranged at a base of the crucible. 9. The apparatus as claimed in claim 6, wherein each of the one or more gas nozzles comprise at least a first section that projects into the crucible. 10. An apparatus for melting glass or glass-ceramic, comprising: a crucible; an emitting device for emitting electromagnetic radiation into a melt in the crucible so that the melt is heated by the electromagnetic radiation; and a mixing device being assigned to the crucible so that the melt can be mixed and/or homogenized while it is still in the crucible, wherein the mixing device introduces a first material to the melt to induce a substantially predefined motion in the melt. 11. An apparatus for melting glass or glass-ceramic, comprising: a crucible; an emitting device for emitting electromagnetic radiation into a melt in the crucible so that the melt is heated by the electromagnetic radiation; a mixing device being assigned to the crucible so that the melt can be mixed and/or homogenized while it is still in the crucible; and an agitator dissolved or melted in the melt. 12. An apparatus for melting glass or glass-ceramic, comprising: a crucible; an emitting device for emitting electromagnetic radiation into a melt in the crucible so that the melt is heated by the electromagnetic radiation; a mixing device being assigned to the crucible so that the melt can be mixed and/or homogenized while it is still in the crucible; one or more gas nozzles; and a device for punching through a solid skull layer on a base of the crucible. 13. The apparatus as claimed in claim 12, wherein said device comprises a needle, and wherein the needle comprises a material selected from the group consisting of tungsten, molybdenum, iridium, and any combinations thereof. 14. The apparatus as claimed in claim 13, wherein the needle is arranged substantially in a center of the one or more gas nozzles. 15. A method for melting a glass or glass-ceramic in a melting crucible, the method comprising: emitting electromagnetic radiation into the melting crucible to form a melt of the glass or glass-ceramic; and mixing or homogenizing the melt, wherein mixing or homogenizing the melt introduces a flow in the melt in predetermined form. 16. The method as claimed in claim 15, wherein the melt is deliberately set in internal motion in order to be mixed or homogenized. 17. The method as claimed in claim 15, further comprising keeping unmelted batch fractions away from a crucible outflow opening by means of a cooled bridge. 18. The method as claimed in claim 15, further comprising introducing a batch into the melt so that the introduction of the batch effects the mixing or homogenization of the melt. 19. The method as claimed in claim 18, wherein the batch is a pelletized and/or coated batch. 20. The method as claimed in claim 18, wherein the batch releases a gas or gas bubbles into the melt. 21. The method as claimed in claim 15, wherein the melt is agitated in order to be mixed or homogenized. 22. The method as claimed in claim 15, further comprising introducing a gas or gas bubbles into the melt for mixing or homogenization purposes. 23. A method for melting a glass or glass-ceramic in a melting crucible, the method comprising: emitting electromagnetic radiation into the melting crucible to form a melt of the glass or glass-ceramic; mixing or homogenizing the melt; and introducing a first material into the melt so that a substantially predefined flow motion is induced in the melt. 24. A method for melting a glass or glass-ceramic in a melting crucible, the method comprising: emitting electromagnetic radiation into the melting crucible to form a melt of the glass or glass-ceramic; mixing or homogenizing the melt; and introducing an agitator into the melt, the agitator dissolving when introduced into the melt.