DE10202024A1 - Apparatus for melting highly pure, aggressive or high melting point glass or glass ceramic comprises crucible, around which electromagnetic coil is wound, fitted with mixer or homogenizing device - Google Patents

Abstract

Apparatus for melting highly pure, aggressive or high melting point glass or glass ceramic comprises a crucible (10), around which an electromagnetic coil (30) is wound. A mixer or homogenizing device, e.g. a gas injection nozzle (50), is fitted into the base of the crucible. Independent claims are included for the following: (a) a method for melting highly pure, aggressive or high melting point glass or glass ceramic using the apparatus; and (b) glass or glass ceramic products produced using the apparatus or method.

Description

The invention relates to an apparatus and a method for Low contamination melting of a substance in general and for melting particularly high-purity, aggressive and / or high-melting glass or glass ceramic in special.

In traditional melting processes, glass becomes continuous melted in a platinum crucible or in refractory trays. The disadvantage here is that the platinum shares in the Melt is released and the refractory tubs only short Have downtimes. The desired high-purity glass quality cannot be achieved here.

Methods are also known in which glass in Melting tanks are continuously melted and removed. Here close to high quality glass received, if necessary a refining channel and a Homogenization device or tub to the melting tank on.

In both processes mentioned, discontinuously or continuously, the crucible or the Melting furnace, e.g. B. heated with a burner from the outside and the heat is transferred to the melt inside forwarded conductively. There is an immediate one Contact between the melt and the crucible or the trough. This has a number of disadvantages.

First, the maximum melt temperature is through that Crucible or tub material limited. Usually exist hence the crucible or the trough and, if necessary the refining trough and the platinum homogenizing trough, which is a relatively high melting temperature and relatively good Has corrosion resistance.

Furthermore, the platinum crucible or the platinum Melting tank, but also the refining channel and the Homogenization tank attacked by the glass melt and corroded.

However, platinum disadvantageously causes Contamination or impurities in the glass, which the optical properties, especially the transmission deteriorate, which is why these conductive heating procedures are only applicable to a limited extent for high-purity glasses. Such impurities lead to transmission losses in optical fiber transmission systems from up to 200 to 500 dB / km.

This proves to be more aggressive, especially for melting Glasses, e.g. B. zinc silicate or lanthanum borate glasses as the highest problematic, since the crucibles or tubs literally "Eat".

In addition to the conductive heating methods mentioned above are still known processes in which glass in one so-called skull crucibles heated and melted inductively becomes.

A skull crucible typically consists of spaced water-cooled metal pipes arranged in a meandering fashion. The melt located inside the skull crucible is over a coil arrangement arranged around the skull crucible by means of Coupling of high-frequency power is heated in the melt.

The cooling of the skull crucible creates between the Skull crucible and the melt one, essentially solid Layer or crust of a species-specific material, d. H. especially made of glass. In this respect, contamination of the Melt significantly reduced by the crucible material.

A skull crucible is e.g. B. from PETROV YU. B. et al., "Continuous Casting Glass Melting in a Cold Crucible Induction Furnace", XV. International Congress on Glass 1989 , Proceedings, Vol. 3a, 1989, pages 72 to 77.

However, due to the complex structure, especially due to the high frequency technology Requirements of an inductively heated skull Melting device compared to the above-mentioned conductive heating melters completely new requirements and Problems. Therefore, a transfer is due first high melting temperature and very high throughputs per Crucible volume of many solutions from conductive heating Devices on skull melters are not without further possible.

Basically, using a skull melter is high Melting rates and thus throughputs can be achieved. This is although desirable, but on the other hand, this can cause Circumstances the quality of the melt and thus the End product, e.g. B. suffer from thermal reduction. Also this leads to deteriorated transmission properties of the Glass.

The coupling rate of the high-frequency radiation also depends on various parameters of the melt. Thus the Melting performance not only by the Coil assembly emitted high-frequency power, but also limited by the melt parameters and crucible geometries.

Consequently, the known skull melters are especially with regard to the quality and homogeneity of the Melt as well as the melting capacity or the Throughput can be further improved.

WO 00/32525 describes a method and a device for glazing organic waste, especially radioactive If known, at which the supply of the oxidation of organic substances serving oxygen both from the surface as well as the bottom of a Crucible is made. The supply of oxygen essentially takes place in such a way that it is locally restricted Influence. However, this will reduce the redox state of the The melt only changes locally and homogenization occurs of the entire melt.

Therefore, it is an object of the present invention to provide a Device and a method, in particular a skull Melting device or a skull melting process for Melting a substance, especially glass or To make glass ceramic available, which is an improved Homogeneity, an increased melting capacity, an increased Throughput and / or high substance or glass quality enable.

Another object of the present invention is known skull melting devices or skull Melting processes continue to develop and the disadvantages to avoid known devices and methods or at least mitigate.

The object of the invention becomes surprisingly simple Way already through the subject matter of claims 1 and 20 solved.

The device according to the invention, in particular skull Melting device for melting or melting a Substance or compound, especially for melting from high purity, aggressive and / or high melting glass or Glass ceramic includes a, preferably coolable, for. B. water-cooled crucible or skull crucible and one Transmitter for electromagnetic radiation, in particular a coil arrangement arranged around the crucible. The transmitter or coil arrangement emits especially high-frequency electromagnetic radiation, which melts into the crucible is coupled so that the melt by means of absorbed high-frequency power is heated. Furthermore is a mixing or homogenizing device for mixing or Homogenization of the melt provided, the mixing or Homogenization device assigned to the crucible, e.g. B. on and / or are arranged in this, so that the mixing or Homogenize in the crucible or crucible can take place.

A mixture of. To be melted continuously is preferred placed on top of the melt in the middle and liquid melt continuously removed from the crucible.

The inventors found that mixing and / or homogenizing the melt already in the Crucible or skull crucible a surprising Multiple benefits can be achieved. First, it becomes unmelted Batch which z. B. from above in solid form in the melt falls, due to increased mixing with the liquid portion the melt melted faster. Surprisingly the inventors have found that the effective Contact area between the melt and the supplied material greatly increased and thus the melting capacity is increased. Second, the temperature distribution of the melt leveled. Third, an even distribution or Mixing of different glass components, which, for. B. different melting temperatures and / or Can have high-frequency coupling coefficients, achieved. Fourth, the redox state of the glass can be set.

The mechanisms of action found are particularly in Connection with the preferred inductive High-frequency heating relevant because the coupling or Coupling of the electromagnetic radiation also from Physical state, the temperature and the respective Glass component in the melt are dependent. In particular is the coupling to unmelted batch components very low.

The device according to the invention and the method are suitable especially for high-melting glasses, where Melt temperatures of at least 1500 ° C or 1600 ° C be driven. They can also be extremely aggressive Glasses, e.g. B. melted zinc silicate or lanthanum borate glasses become.

Mixing or homogenization is preferred contamination-free or at least low-contamination what is particularly advantageous for high-purity glasses.

Preferably the melt is for mixing or Homogenize specifically or in a predetermined manner into internal ones Movement or an internal movement stimulated, supported and / or maintained. In particular, a predefined flow, e.g. B. with predefined flow rate and / or Flow direction excited in the melt. It can e.g. B. through the targeted generation of a temperature difference in the Melt a convection flow, or one existing convection flow stimulated, supported or be reinforced.

Mixing or homogenization can be done with or without Introduction of material into the melt or induced be generated.

A preferred form of material mixing includes the introduction of batches which are of this type is trained that just by bringing it in z. B. a flow in the melt is excited. To this Purpose is z. B. a pelleted and / or coated batch, in which gas bubbles in particular are enclosed and / or which releases gas bubbles when it melts, used. Without these gas bubbles, the batch can pelleted, coated and / or otherwise compacted be fed. For the purposes of the invention, this is used as Pelleting bringing together to a stable solid, understood for example by means of presses. As a drug one with a, for example, glass-like coating solid structure understood. This will in particularly advantageously both by dust feeding granular and fine granular material avoided and also the filling rate essential improved, because with the same volume flow a clearly increased material input into the melt can take place. Mixture components can also be obtained through finer-grained Material can be substituted without making it too elevated Dust comes through, due to the fine-grained material by means of shortened diffusion paths to an optimized one Melting speed is coming.

Alternatively or additionally, a z. B. too Rod-shaped batch, which in particular by rotating sinking into the melt mixing or Homogenization creates a feeling of excitement. The z. B. propeller-shaped Bars in particular define a self-dissolving one Stirrer.

Alternatively or in addition, an external one can also be used Stirring device, in particular made of coated metal for mechanical stirring or immersion in the melt and yourself, e.g. B. from melting self-dissolving stirrers the melt material may be provided.

A particularly preferred embodiment of the invention comprises a device for introducing gas or Gas bubbles, e.g. B. by means of one or more gas nozzles in the Melt. The gas nozzle is preferably cooled, especially liquid cooled, e.g. B. water-cooled and is preferably on Bottom of the crucible arranged. The cooling of the gas nozzle can connected to the cooling of the crucible or separately be trained.

According to a particularly preferred embodiment, the Gas nozzle at least in sections through the bottom of the crucible and extends into the interior of the crucible.

In particular, a tip of the gas nozzle extends up to or in the melt, leaving the gas nozzle or tip escaping gas in the form of gas bubbles in the melt rises. This "bubbling" is particularly easy Way mixing and homogenizing the melt in the Aufschmelztiegel.

O ₂ -containing gas is preferably used, which has proven to be very advantageous in particular for lead silicate glasses. This is because the lead is thermally reduced at a high melt temperature, which is used for a high melting capacity. This in turn causes a deterioration in transmission of the glass, similar to a platinum contamination, which can lead to severe discoloration, which makes the melted glass completely unusable. The introduction of oxygen into the melt prevents the lead from being reduced, so that an effective control of the redox state of the glass is achieved via the gas introduction. This can even z. B. for lead silicate glass a melting capacity of about 500 kg / day, 800 kg / day, 1000 kg / day or more can be achieved and at the same time a significant deterioration in transmission can be avoided or at least reduced.

The section of the nozzle which is in the melt is preferred protrudes, e.g. B. the tip made of low-contamination material, z. B. a light metal, especially aluminum, magnesium or beryllium or is at least with one Material coated. A coating with Polytetrafluoroethylene (Teflon®) also appears possible.

To "freeze" the gas nozzle, e.g. H. after a Form a solid substance or glass layer over the Gas nozzle to open it or to clear it again, the gas nozzle preferably comprises a device for Puncturing a solid substance or skull layer. This Device for piercing is in particular as a needle, for. B. made of high temperature resistant material such as tungsten or similar metal. Preferably, the needle is in the Center of the gas nozzle, preferably longitudinally displaceable arranged.

In the following, the invention is based on preferred Embodiments and with reference to the figures explained in more detail, the same reference numerals being the same or denote similar elements.

Brief description of the figures

Show it:

Fig. 1 is a schematic sectional drawing of a first embodiment of the inventive device with a gas nozzle,

Fig. 2 is a schematic plan view from above of a section of the crucible bottom of the first embodiment of the invention,

Fig. 3 is a schematic sectional drawing of a detail of the crucible bottom taken along section line AA in Fig. 2,

Fig. 4 is a schematic sectional view of an upper portion of the gas nozzle according to the first embodiment of the invention,

Fig. 5 is a longitudinal section of the gas nozzle according to the first embodiment of the invention,

Fig. 6 is a cross-section of the gas nozzle along the section line BB in Fig. 5,

Fig. 7 is a schematic sectional drawing of a second embodiment of the invention,

Fig. 8 is a schematic sectional view of a third embodiment of the invention,

Fig. 9 is a schematic sectional drawing of a fourth embodiment of the invention and

Fig. 10 is a schematic perspective view of a self-dissolving agitator according to a fifth embodiment of the invention, and

Fig. 11 is a schematic sectional drawing of the first embodiment of the invention with a refining trough and a homogenization trough.

Detailed description of the invention

Fig. 1 shows a first embodiment of the device 1 according to the invention for melting glass with a cooled, for. B. water-cooled crucible or crucible 10 . A transmitter for electromagnetic radiation in the form of a coil arrangement 30 is arranged around the crucible 10 .

By means of the coil arrangement high-frequency power in a melt 40 z. B. coupled from lead silicate glass and thus heated the melt 40 . It works with a high frequency of about 250 kHz to about 400 kHz with a transmission power of about 200 kW to about 300 kW or higher. The temperature of the melt is in the range from 1200 ° C to 2000 ° C.

The crucible 10 comprises a water-cooled annular wall section 12 and a water-cooled bottom 14 . The wall section 12 and the bottom 14 together form the cooled wall of the crucible 10 . and each include meandering and spaced apart metal tubes 16 , as best seen in FIGS. 2 and 3. The metal tubes 16 have a cross section of approximately 2 cm and gaps of 5 mm between the tubes 16 , so that the crucible wall is initially liquid-permeable when the crucible 10 is unfilled.

Due to the cooling of the wall section 12 and the bottom 14 , that is to say the crucible wall, a solid, closed skull layer 42 is formed in the contact area of the melt 40 and the crucible wall from a material of its own type, that is to say from glass in this exemplary embodiment, as a result of which the arrangement from the crucible 10 and the solid Skull layer 42 becomes liquid-tight. Fig. 1, the individual tubes 16, and the skull layer 42 does not show in a schematic representation of the crucible.

With further reference to FIG. 1, it is noted that the melting device is operated continuously, so that batches are regularly placed on the melt through an essentially central opening 20 in a cover 18 of the crucible 10 . Furthermore, melt is continuously removed via an outlet opening 22 of the crucible 10 .

A cooled bridge 24 dips near the outlet opening 22 at least about 3 cm to 5 cm deep into the melt 40 in order to keep unmelted or undissolved batch constituents away from the outlet opening 22 .

The device 1 further comprises two burners 26 , 28 which direct flames 27 , 29 through openings in the cover 18 to the contents of the crucible or a surface 41 of the melt 40 . Here, the burner 26 serves to initially melt the crucible contents when starting the device 1 , for. B. after a crucible change and the burner 28 for the continuous reheating of the melt 40 in the outlet opening 22 .

A mixing or homogenizing device in the form of a gas nozzle 50 is arranged on the bottom 14 of the crucible 10 . The gas nozzle 50 projects in sections into the crucible and introduces the gas into the melt 40 .

Furthermore, the gas nozzle 50 is arranged eccentrically, in this exemplary embodiment approximately centrally between the center and the edge of the round crucible 10 and opposite the outlet opening 22 . This position has proven to be very advantageous, since a convection flow 54 that rises and falls at the edge due to temperature difference in the melt and is centrally supported by a hot core 43 is supported and at the same time batch is placed centrally through the opening 20 by means of the gas bubbles 52 from the cold crucible wall 12 is kept away. The essentially annular flow 54 advantageously brings about effective mixing and homogenization of the melt and thus ensures temperature compensation and a uniform material distribution in the melt.

In this example, the gas bubbles contain O ₂ in order to simultaneously oxidize lead in the lead silicate glass melt 40 .

FIG. 2 shows a schematic view from above of the crucible bottom 14 with the gas nozzle 50 , which is arranged in an opening 15 or recess in the crucible bottom 14 between the meandering metal tubes 16 .

As further shown in FIG. 3, the skull layer 42 is formed not only on the cooled bottom 14 of the crucible, but also on the cooled gas nozzle 50 . The escaping gas bubbles 52 ensure, however, that an opening of the gas nozzle is kept permanently free.

Nevertheless, e.g. B. due to an interruption in the gas supply, the solid skull layer 42 closes over an outlet opening 56 of the gas nozzle 50 , so that no more gas can escape from the nozzle 50 . This state is shown in Fig. 4. In order to clear the opening 56 again, the gas nozzle comprises a needle 58 , which is arranged in the direction of arrow 59 and can be displaced longitudinally within a channel 60 in the center of the gas nozzle. With a tip 62 of the needle 58 thus a reclining above the gas outlet opening 56 portion 42 can penetrate the skull a layer 42, and so the gas outlet opening 56 be freed again.

The inventors have found that an upper section 51 of the gas nozzle 50 , which projects into the crucible 10 and at least in sections is in direct contact with the skull layer 42, is preferably made of non-contaminating or at least low-contamination material. For the purposes of the invention, low-contamination materials are those which essentially do not or only slightly impair the glass quality. These are especially light metals, such as. B. aluminum. Although aluminum enters the melt, aluminum ions or aluminum compounds have essentially no or little disadvantageous effect on the optical properties, in particular the transmission of the glass. The cooling of the gas nozzle 50 , on the other hand, ensures that the gas nozzle 50 withstands the high temperatures in the crucible 10 .

Furthermore, the use of a metal with a high melting point, e.g. B. higher than 2000 ° C, especially molybdenum, iridium, tungsten or a tungsten compound has proven to be advantageous for the needle 58 .

Fig. 5 shows the gas nozzle 50 in a longitudinal section. The gas nozzle 50 comprises the gas outlet opening 56 and the gas channel 60 , in which the needle 58 runs and is guided. By means of a displacement device 64 , the needle 58 can be displaced parallel to the channel 60 within the gas nozzle 50 . The gas nozzle 50 further includes a gas inlet 66 and a seal 68 for the needle 58 . The upper section 51 of the gas nozzle 50 comprises aluminum or an aluminum-containing alloy, a lower section 53 of the gas nozzle 50 being made of brass. The upper and lower sections 51 , 53 are sealed against one another in a fluid-tight manner by seals 70 . In the lower section 53 there is a cooling water inlet 72 and a cooling water outlet 74 , so that the gas nozzle can be effectively cooled by means of water flow.

Referring to FIG. 6, which shows a cross section of the nozzle, it is shown that the lower section 53 is divided into two halves 53 a, 53 b parallel to a longitudinal axis L of the gas nozzle 50 , which are electrically insulated from one another.

FIG. 7 shows a second embodiment of the device 101 according to the invention with an alternative device 150 for mixing and homogenizing the melt 40 . A batch of glass formed into pellets, dragees and / or balls 156 is introduced into the melt 40 through the opening 20 via a conveyor belt 154 . The glass balls 156 comprise an outer edge region 158 and an inner core region 160 . The edge region 158 essentially comprises glass of the composition of the melt 40 . The core region 160 comprises a substance which in the melt is a gas or gas bubbles. 152 releases when the edge region 158 has melted. The substance in the core region 160 can be a gas, a liquid, e.g. B. water or a solid material, e.g. B. include a salt, which in cooperation with the hot melt 40 release the gas bubbles 152 .

By sinking the glass balls 156 in a left section 40 a of the melt and rising gas bubbles 152 in a right section 40 b of the melt 40 , an essentially annular flow is generated or induced within the melt 40 . However, as is shown in FIG. 1, an existing convection flow can also be supported.

FIG. 8 shows a third embodiment of the device 201 according to the invention, in which batch bodies 256 pressed in the form of bars are introduced into the melt 40 by means of a mixing and homogenization device 250 . The rod-shaped body 256 are, for. B. of propeller-like shape and rotate when sinking within the melt 40 with simultaneous melting of the body 256 and thereby generate flow processes in the melt 40th

FIG. 9 shows a fourth embodiment of the device 301 according to the invention with a stirrer 350 which mechanically sets the melt 40 in the melting crucible 10 by rotating movement.

Fig. 10 shows a preferred embodiment of an elongated stirrer 350 '. The stirrer 350 'is essentially made of glass, e.g. B. pressed, which also forms the melt 40 . The stirrer 350 'is along its longitudinal axis 352 z. B. similar to the stirrer 350 in Fig. 9 from above into the melt 40 and rotated about its axis 352 . The stirrer 350 'comprises three stirrer arms extending from the center and dissolves itself in the melt 40 by melting. In order to ensure continuous glass addition and stirring, the stirrer 350 'is correspondingly continuously fed from above.

Fig. 11 shows the first embodiment of the device 1 according to the invention with a connected refining channel 80 and an additional external homogenizing 90th Liquid glass is continuously fed from the crucible 10 along the arrow 82 into the refining groove 80 and from there along the arrow 84 into the external homogenization device 90 . The external homogenizer 90 includes a glass outlet 92 for pouring e.g. B. in a form and / or for further or finishing the glass to a glass product or glass ceramic product.

The quality of the glass is further improved by refining the glass in the refining groove 80 and re-homogenizing in the external homogenizing device 90 . The glass quality achieved with the device according to the invention can, however, already be so high that the refining channel 80 and / or the homogenization device are not necessary, so that the glass melt 40 is already available at the outlet opening 22 for further or final processing.

It will be apparent to those skilled in the art that the invention is not based on the above-described embodiments are limited is and can be varied in many ways without the Leave the spirit of the invention.

Claims (32)

1. Device ( 1 , 101 , 201 , 301 ) for melting a substance, in particular for melting high-purity, aggressive and / or high-melting glass or glass ceramic, comprising
a crucible ( 10 ),
a transmission device ( 30 ) for electromagnetic radiation, wherein the radiation can be used to couple energy into a melt ( 40 ) which can be arranged in the crucible ( 10 ) and
a mixing device or homogenizing device ( 50 , 150 , 250 , 350 , 350 ') which are assigned to the crucible ( 10 ). 2. Device ( 1 , 101 , 201 , 301 ) according to claim 1, characterized in that the mixing device or homogenization device ( 50 , 150 , 250 , 350 , 350 ') are designed such that contamination-free or at least contamination-free mixing or homogenization takes place , 3. Device ( 1 , 101 , 201 , 301 ) according to claim 1 or 2, characterized in that by means of the mixing device or homogenization device ( 50 , 150 , 250 , 350 , 350 ') the melt ( 40 ) can be set in internal movement in a targeted manner , 4. The device ( 1 , 101 , 201 , 301 ) according to one of the preceding claims, characterized in that a predefined flow in the melt ( 40 ) can be excited by means of the mixing device or homogenization device ( 50 , 150 , 250 , 350 , 350 ') , 5. Device ( 1 , 101 , 201 , 301 ) according to one of the preceding claims, characterized in that by means of the mixing device or homogenization device ( 50 , 150 , 250 , 350 ') a first material ( 52 , 156 , 256 ) into the melt ( 40 ) can be introduced, wherein an essentially predefined movement in the melt ( 40 ) can be excited by means of the first material ( 52 , 156 , 256 ). 6. The device ( 1 , 101 , 201 , 301 ) according to one of the preceding claims, characterized in that the crucible ( 10 ) has an outflow opening ( 22 ) for the melt ( 40 ) and a, in particular cooled bridge ( 24 ), which in the melt ( 40 ) is immersed, unmelted batches being kept away from the outflow opening ( 22 ) by means of the bridge ( 24 ). 7. The device ( 101 , 201 ) according to any one of the preceding claims, characterized in that a mixture ( 156 , 256 ) is included, the composition or shape of which are designed such that the mixture ( 156 , 256 ) is introduced into the melt ( 40 ) mixing or homogenizing the melt ( 40 ) can be effected. 8. The device ( 101 , 201 ) according to one of the preceding claims, characterized in that a pelletized and / or coated mixture ( 156 , 256 ) that can be introduced into the melt ( 40 ) is included. 9. The device ( 101 ) according to one of the preceding claims, characterized in that a mixture ( 156 ) which can be introduced into the melt ( 40 ) and which releases a gas or gas bubbles ( 152 ) during melting is included. 10. Device ( 301 ) according to one of the preceding claims, characterized in that the device comprises a stirring device ( 350 , 350 ') which is assigned to the crucible ( 10 ). 11. The device ( 301 ) according to any one of the preceding claims, characterized in that a stirrer ( 350 ') is included, which can be dissolved or melted in the melt ( 40 ). 12. The device ( 1 ) according to any one of the preceding claims, characterized in that a device ( 50 ) for introducing gas or gas bubbles ( 52 ) into the melt ( 40 ) is included. 13. The device ( 1 ) according to one of the preceding claims, characterized in that one and / or more gas nozzle (s) ( 50 ) is (are) included. 14. The device ( 1 ) according to claim 13, characterized in that the gas nozzle (s) ( 50 ) is cooled, in particular liquid-cooled. 15. The device ( 1 ) according to claim 13 or 14, characterized in that the gas nozzle ( 50 ) on the bottom ( 14 ) of the crucible ( 10 ) is arranged. 16. The device ( 1 ) according to claim 13, 14 or 15, characterized in that at least a first section ( 51 ) of the gas nozzle ( 50 ) projects into the interior of the crucible ( 10 ) and / or the first section ( 51 ) low-contamination material , especially light metal, e.g. B. includes aluminum. 17. The device ( 1 ) according to one of the preceding claims, characterized in that a device ( 58 ) for piercing a solid skull layer ( 42 , 42 a) located on the crucible wall ( 12 , 14 ), in particular on the crucible bottom ( 14 ), is included , 18. Device ( 1 ) according to one of the preceding claims, characterized in that a needle ( 58 ) for piercing a solid skull layer ( 42 , 42 a) located on the crucible wall ( 12 , 14 ), in particular on the crucible bottom ( 14 ), is included , the needle ( 58 ) containing high temperature resistant material, in particular tungsten, molybdenum and / or iridium. 19. The device ( 1 ) according to claim 18, characterized in that the needle ( 58 ) is arranged substantially in the center of the gas nozzle ( 50 ). 20. A method for melting a substance, in particular for melting high-purity, aggressive and / or high-melting glass or glass ceramic, in particular for operating the device ( 1 , 101 , 201 , 301 ) according to one of the preceding claims, the method comprising
Provision of a crucible ( 10 )
Providing a transmitting device ( 30 ) for electromagnetic radiation,
in particular cooling the crucible ( 10 ),
Heating a melt located in the crucible by means of electromagnetic radiation which is emitted by the transmitting device ( 30 ) and
Mixing or homogenizing the melt ( 40 ) in the crucible ( 10 ). 21. The method according to claim 20, characterized in that the mixing or homogenization of the melt ( 40 ) is carried out contamination-free or at least contamination-free. 22. The method according to claim 20 or 21, characterized in that for mixing or homogenization, the melt ( 40 ) is deliberately set in internal movement. 23. The method according to any one of the preceding method claims, characterized in that a flow in the melt ( 40 ) is excited in a predetermined manner for mixing or homogenizing. 24. The method according to any of the preceding method claims, characterized in that for mixing or homogenizing a first material (52, 156, 256) is introduced into the melt, wherein the first material (52, 156, 256) has a substantially pre-defined flow movement in the melt ( 40 ) causes or at least stimulates. 25. The method according to any one of the preceding method claims, characterized in that a crucible ( 10 ) with an outflow opening ( 22 ) for the melt ( 40 ) and a, in particular cooled bridge ( 24 ), which is immersed in the melt ( 40 ), is provided is, whereby unmelted batches are kept away from the outflow opening ( 22 ) by means of the bridge ( 24 ). 26. The method according to any one of the preceding method claims, characterized in that a batch ( 156 , 256 ) is introduced into the melt ( 40 ), the composition of the batch ( 156 , 256 ) or the shape of batch components being designed such that the introducing the mixture (156, 256) causes in the melt (40) a mixing or homogenization of the melt (40). 27. The method according to any one of the preceding method claims, characterized in that a pelleted and / or coated batch ( 156 , 256 ) is introduced into the melt ( 40 ). 28. The method according to any one of the preceding method claims, characterized in that a mixture ( 156 ) is introduced into the melt ( 40 ), which releases a gas or gas bubbles ( 152 ) during melting. 29. The method according to any one of the preceding method claims, characterized in that the melt ( 40 ) is stirred for mixing or homogenization. 30. The method according to any one of the preceding method claims, characterized in that a self-dissolving stirrer ( 350 ') is introduced into the melt ( 40 ). 31. The method according to any one of the preceding method claims, characterized in that a gas or gas bubbles ( 52 ) are introduced into the melt for mixing or homogenizing. 32. Glass product or glass ceramic product, produced or producible by means of the device ( 1 , 101 , 201 , 301 ) according to one of the preceding device claims or according to the method according to one of the preceding method claims.