Glass furnace

Abstract

The invention relates to a glass furnace (10, 10a, 10b, 10c, 110, 210, 310, 410) for completely electrically heating a glass melt (12) in a production operating state, having a side wall made of a refractory material, which laterally surrounds an inner furnace space (11, 111, 211, 311, 411), in which the glass melt (12) is arranged in the production operating state. In order to achieve a higher glass yield while simultaneously achieving a compact design and a high quality glass, the side wall has an inner wall section (15, 115, 215, 315, 415) and an outer wall section (16, 116, 216, 316, 416) arranged opposite the inner wall section, wherein a hot space side (15b, 115b, 215b, 315b) of the inner wall section (15, 115, 215, 315, 415) facing the inner furnace space and a hot space side (16b, 116b, 216b, 316b) of the outer wall section (16, 116, 216, 316, 416) facing the inner furnace space substantially have the shape of an inner lateral surface and an outer lateral surface of a hollow body having a continuous hollow space or a corresponding hollow body section, the hollow body being, for example, a hollow cylinder or a hollow prism, wherein the inner wall section (15, 115, 215, 315, 415) at least partially surrounds a continuous gap (19, 20, 119, 319, 419) corresponding to the hollow space. A system including two glass furnaces, a glass melting apparatus, and a method of manufacturing a glass furnace are also described.

Description

[0001] The invention relates to a glass melting furnace for the fully electrical heating of a glass melt in production operation, a glass melting plant and a method for producing a glass melting furnace.

[0002] A furnace (glass melting furnace) for producing a glass melt generally comprises a bottom and side walls surrounding the interior space of the furnace. In the production operation state, the glass melt is contained in the interior space of the furnace and is limited by the side walls in the lateral direction and by the bottom of the furnace at the bottom. The interior space of the furnace is also at least partially covered by a top cover to reduce the loss of heat energy and / or the release of exhaust gases and dust. In the interior space of the furnace, the glass melt flows from the melting zone in one direction to at least one outlet opening (through which the molten glass is discharged) during the melting process, and in the melting zone, a raw material mixture and cullet (if applicable) are supplied to the interior space of the furnace. The discharged molten glass can be used, for example, to make container glass, flat glass, rolled glass, glass fiber, glass fiber, household glass or industrial glass.

[0003] Glass melting furnaces for vitrifying fly ash or industrial waste as the main product of cement clinker are known from documents EP 0 019 645 A1, CN 110425881A, EP 0 118 580 A1 and DE 692 11 446 T2. This material is characterized by a steeper viscosity curve than glass. These documents describe glass melting furnaces that can be used specifically for this material, in which the molten material is discharged in the central region of the corresponding furnace by means of a corresponding overflow / siphon located in the central region.

[0004] So-called cold top furnaces usually include a layer of raw materials (raw material mixture and / or cullet) that has not yet melted, which is located on top of the glass melt and completely covers it. The temperature of this layer is significantly lower than the temperature of the glass melt, which is why it is called "cold". The "cold" covering has the known advantages of thermal insulation and serving as a resource-saving condensate collector. With cold top technology, the glass generally flows in a vertical direction (i.e. from top to bottom) and is discharged at the bottom or laterally from the bottom.

[0005] Fully electrically heated glass melting furnaces with a closed top furnace are known and are currently used in particular for smaller glass production (conveying capacity / melting capacity / tonnage) for good quality glass in the range of up to 250 tons of molten glass / day. From document US 3,520,979, a glass melting furnace with an electrically heated system is known, wherein the interior of the furnace has the shape of a complete hexagonal prism, wherein electrodes protrude from the side walls into the molten glass. The glass melting furnace shown in document DE 34 05 273 C2 also has the same shape as the interior of the furnace, wherein the electrodes in this version are designed as top electrodes. Document US 3,885,945 discloses an electrically heated cubic interior of a furnace with a horizontal flow direction of the molten glass. Today, glass melting furnaces with fully electrically heated operation are mainly operated according to the cold top principle, i.e. a "cold" raw material mixture and / or a cullet cover is arranged on the glass bath (Glasbad).

[0006] The importance of climate protection and the associated societal pressure on energy-intensive processes used in the glass industry are increasing. The processes currently available for obtaining renewable energy mainly generate electrical energy, which is the most useful form of direct energy use. By using electrical energy (for example in the form of heating with the aid of electrodes based on the Joule effect) to melt the glass directly, a high level of efficiency can be achieved. In contrast, for example, converting electrical energy generated by renewable energy into another energy carrier (for example hydrogen) and heating by burning this energy carrier would result in significantly greater energy consumption in the overall analysis. There is therefore a great deal of interest in increasing the use of direct electrical heating of glass furnaces, in particular for glass furnaces that are intended to achieve higher production rates.

[0007] Other factors that influence the further development of glass melting furnace technology are the required glass quality and the size of the glass melting furnace or the space available for the glass melting furnace in the production line, respectively. In many cases, the glass quality should be high, i.e. the bubble density in the final product should be less than 60 small bubbles per 100 grams of glass. On the other hand, the space available for the glass melting furnace is often limited. In addition, large aggregates are considered too demanding in terms of construction and operation for many applications.

[0008] Therefore, the object of the present invention is to provide a compact glass melting furnace which can be fully electrically heated in production operation, provides good glass quality and is suitable for higher glass production. In addition, the object is to provide a cost-effective and simple process for manufacturing such a glass melting furnace.

[0009] This object is achieved by a glass melting furnace having the features of claim 1 and a method for producing a glass melting furnace having the features of claim 16. This object is further achieved by a system having two glass melting furnaces comprising the features of claim 14 and a glass melting plant having the features of claim 15.

[0010] In particular, the above-mentioned purpose is achieved by a glass melting furnace for fully electrically heating a glass melt in a production operation state, the glass melting furnace comprising a side wall made of a refractory material, the side wall laterally surrounding an inner space of the furnace, wherein the glass melt is arranged in the inner space of the furnace in the production operation state, the surface of the side wall extends horizontally, wherein the side wall comprises an inner wall section and an outer wall section positioned opposite to the inner wall section, wherein the hot space side of the inner wall section facing the inner space of the furnace and the hot space side of the outer wall section facing the inner space of the furnace each basically have the shape of an inner shell surface and an outer shell surface of a hollow body, the hollow body having a through hollow space or a corresponding hollow body section, wherein the hollow body is, for example, a hollow cylinder or a hollow prism, wherein the inner wall section at least partially surrounds a through open space corresponding to the hollow space and extending in a vertical direction.

[0011] The glass melting furnace according to the invention comprises an inner space of the melting furnace, which is delimited below by a bottom and laterally by side walls, both of which are made of refractory material. The side walls comprise all side walls of the glass melting furnace, including any two intermediate walls (one intermediate wall may be arranged between the inner wall section and the outer wall section), if such intermediate walls are present. In the production operation state, the glass melt is contained in the inner space of the melting furnace. According to the invention, the hot space side of the inner wall section facing the glass melt and the hot space side of the outer wall section facing the glass melt substantially have the shape of the inner shell surface and the outer shell surface of a (completely surrounded) hollow body, which has a through hollow space extending in the vertical direction or (in the case of incomplete surrounding) a corresponding hollow body section. "Substantially" means that the two hot face sides may include recesses (for example, for side electrodes or top electrodes) and steps, which recesses and steps may not be taken into account when considering the general shape of these surfaces. Importantly, there is a through open space in the glass melting furnace, which extends in the vertical direction, is formed by the inner wall segments and is completely or partially surrounded by the inner wall segments. The term "through open space" means that the inner wall segments are connected to the bottom of the glass melting furnace, so that the inner wall segments limit the glass melt to the entire glass level depth in the inner space of the melting furnace in the direction of the open space, so that the open space passes through and extends beyond the entire glass melt. Therefore, the inner wall segments extend above the liquid level of the cold batch material surface, and therefore also extend above the glass melt liquid level. Therefore, the open space is not configured as an outlet. This is also derived from the above description, which explains that the inner wall segments laterally surround the inner space of the furnace. During the operation of the glass melting furnace (i.e., in the production operation state), the glass melt cannot enter the open space. Embodiments in which the open space is not completely surrounded by the inner wall segments but only partially surrounded relate to the circumference of the open space (i.e., as described below, the open space forms a hollow body segment) when the open space is observed in a substantially horizontal cross section (i.e., perpendicular to the longitudinal axis of the open space extending in a substantially vertical direction). In particular, "partially surrounded" does not refer to the height of the open space, but to its circumference. Thus, the open space can be completely or partially surrounded by the inner wall segments relative to its circumference. In the hollow body model for comparing the shape of the hot space side of the inner wall segments and the outer wall segments, the inner shell surface surrounds the hollow space of the hollow body, while the outer shell surface surrounds the hollow body laterally on the outside. The base and cover surfaces of the hollow body are not part of the shell surface. The open space corresponds to the hollow space of the reference hollow body, wherein the open space is smaller than the thickness of the inner wall segment. This means that, in the production operating state, the interior space of the furnace or the glass melt contained therein substantially assumes the shape of the corresponding hollow body or hollow body segment, wherein the specific design of the bottom and cover of the interior space of the furnace is not taken into account here. The inner space of the furnace surrounds the open space completely (if it is configured as a hollow body) or partially (if it is configured as a hollow body segment).The open space is preferably located in the central area of ​​the glass melting furnace (viewed in the horizontal direction) relative to the entire hollow body. The hollow body can be configured, for example, as a hollow cylinder or a hollow prism, wherein similar to the hollow cylinder, the hollow prism includes a recess as a hollow space, which preferably extends in the center of the prism and / or parallel to the axis of rotational symmetry. The hollow prism can be a triangle, a rectangle, a pentagon or a hollow prism with more than five outer sides. The axis of the hollow prism or hollow cylinder can extend in the vertical direction of the glass melting furnace. The inner wall section surrounds the open space, which is advantageously accessible to the technical equipment used on or in the glass melting furnace and the corresponding operators. The inner wall section forms a convex surface on its hot space side, while the outer wall section is configured as a concave surface on its hot space side. The two hot space sides can include a curved shape (i.e., the shape of a (partial) cylindrical surface) or be flat in multiple parts, i.e., can have the shape of a (partial) prismatic surface. The longitudinal axis of the glass melting furnace extending essentially in the vertical direction can extend parallel to the longitudinal axis of the open space, wherein the two axes can also lie one above the other.

[0012] Observed in a horizontal cross section, the interior space of the furnace has the shape of a ring or ring segment, whose inner and outer edges may be curved (i.e., as a circular or elliptical line) or angled. The horizontal width between the hot space side of the inner wall segment and the hot space side of the outer wall segment of the interior space of the furnace is also referred to as the ring width RB. The hot space side of the inner wall segment may or may not be concentric with the hot space side of the outer wall segment.

[0013] In the vertical direction, the interior space of the furnace has a predetermined height, wherein the height is measured from the bottom of the side wall to the upper edge. The height of the glass melt in the interior space of the furnace in the production operation state is also called the glass level depth. The glass level depth refers only to the height of the melt, not to the cold raw material mixture and / or the covering of cullet located above the melt. The glass level depth is a value assigned to the interior space of the glass melting furnace and does not usually correspond to the glass level depth in the feeder.

[0014] The bottom of the glass melting furnace or the inner space of the furnace can be an annular disk, i.e., have a through opening in the region of the open space, or be disk-shaped (without a through opening). In the case of a disk-shaped bottom, the open space can only be approached from above.

[0015] In an embodiment in which the interior space of the furnace comprises the shape of a hollow body segment (and correspondingly comprises a hot space side of an inner wall segment and a hot space side of an outer wall segment), the interior space of the furnace does not cover 360° when viewed along a horizontal cross section, but covers a smaller angle, but in one embodiment at least covers an angle of 120°. Therefore, the interior space of the furnace does not form a complete ring in a horizontal cross section, but only a partial ring segment. In this embodiment, the inner wall segments of the side walls do not completely surround the open space, but only partially surround the open space. This embodiment comprises an interior space of a melting furnace, which has a smaller volume than the interior space of a glass melting furnace, in which the interior space of the melting furnace has the shape of a completely enclosed hollow body, but otherwise has the same characteristics as explained above and below.

[0016] The cold space sides of the side walls of the glass melting furnace, each facing away from the interior space of the furnace (i.e. the cold space sides of the inner wall segments and outer wall segments and, if applicable, the intermediate walls) can extend substantially parallel to the corresponding hot space sides. The cold space sides can be at least partially or completely insulated.

[0017] The open space extending substantially in the vertical direction may have the shape of a cylinder or a prism, wherein the longitudinal axis of the open space extends parallel to the longitudinal axis of the interior space of the furnace or is inclined at a small angle of up to 30°. Preferably, the two longitudinal axes are identical. Preferably, the hollow body is a rotationally symmetrical hollow body, wherein rotational symmetry means that the hollow body is mapped onto itself by rotating around the longitudinal axis around certain predetermined angles. In one embodiment, the hollow body is a substantially straight hollow body, since a straight hollow body is less expensive in the realization of such a glass melting furnace.

[0018] By means of the novel shape of the interior space of the furnace of the hollow body or hollow body segment as described above, wherein the interior space of the furnace represents the space for melting the supplied raw material mixture and / or the supplied cullet and for refining the glass melt, the glass melting furnace can be scaled up to a higher glass production (up to 1,200 tons / day), wherein the glass melting furnace simultaneously takes a compact shape, which is easily accessible from the outside or from the inside via an open space. This shape is usually formed by fence elements made of refractory materials, which are adjacent to each other and / or placed on top of each other and fixed in place. The refractory material can be, for example, an inorganic, non-metallic material (ceramic, glass, glass ceramic, mineral fiber), and can include oxides, such as silicon oxide, aluminum oxide, magnesium oxide, calcium oxide, zirconium oxide, chromium oxide. In addition, carbon and silicon carbide can be used as components. For example, melt-cast AZS (aluminates, zirconates, silicates, and oxides of aluminum, zirconium and silicon) is used as material. In addition, the refractory material on the hot space side can include at least one coating, such as platinum or a platinum alloy.

[0019] In one embodiment, the glass melting furnace is configured to operate according to the cold top principle. This means that the raw material mixture and / or cullet is fed from above toward the surface of the glass melt, which surface is preferably completely covered. The glass melt is heated by means of electrodes which extend into the glass melt from above (top electrodes), laterally from inner and / or outer wall sections of the wall (side electrodes) and / or from the bottom.

[0020] The flow direction of the glass in the glass melting furnace according to the invention is generally from top to bottom (vertically), i.e. from the surface of the glass melt towards the bottom of the interior space of the furnace, wherein at least one outlet opening through which the molten glass is discharged is arranged in the bottom region or in the region of the outer wall section of the side wall close to the bottom of the interior space of the furnace. In one embodiment, in the bottom region (referred to as a submerged outlet, see for example according to Fig.10 , Fig.11 and Fig.12 ) or in the region of the outer wall section of the side wall (referred to as a straight outlet, see e.g. according to Fig. 9 and Fig.13 In an embodiment of the present invention, two or three outlet openings are arranged adjacent to or opposite to each other. If the outlet is located at the bottom of the inner space of the furnace as an immersed outlet, the at least one outlet opening is arranged near the outer wall segment. If the circular or square but essentially annular bottom of the glass melting furnace is divided into two (or three) segments in the radial direction (relative to the vertical axis extending in the open space) relative to the ring width RB, namely into one (or two) inner segments (inner ring segments) closest to the open space and an outer segment (outer ring segment) closest to the outer wall segment, then at least one outlet opening is particularly arranged in the outer segment, namely in the area of ​​the outermost third to the outermost half of the bottom. In one embodiment, the outlet opening is designed so that it starts in the outer segment of the bottom in the radial direction and extends to the outer wall segment. In the circumferential direction (perpendicular to the radial direction), the outlet opening may have, for example, a width of at least 200 mm and may be in the range of, for example, 250 mm to 1200 mm and may have a height of 200 mm to 900 mm (measured vertically from the bottom of the outlet opening or outlet upwards to the bottom of the glass furnace). The outlet opening in the region of the outer wall section may also have a width in the range between 250 mm and 1200 mm and a height of 200 mm to 900 mm (dimension in the vertical direction).

[0021] In the flow direction of the glass melt, each outlet opening then travels along a horizontal channel, a vertical riser (rising pipe) and a horizontal regulating pipe, the glass level of which corresponds to the glass level in the glass melting furnace. In the regulating pipe, the temperature of the glass melt is slowly reduced from the higher temperature of the glass melting furnace to the lower temperature required for processing the glass melt (usually in the range of 1050° C. to 1350° C.), while the glass melt flows in the regulating pipe in the direction of the corresponding processing device. The regulating pipe can have a width in the range of 250 mm to 3,000 mm, at least in cross section. The depth of the glass level in the area of ​​the regulating pipe can, for example, be in the range between 150 mm and 650 mm.

[0022] The term "in production operation" of a glass furnace means that the glass which is melted in the glass furnace and discharged through the at least one outlet opening is used to produce flat glass, insulating glass, fiberglass or special glass. This is to be distinguished from operation in which the glass production is slowly ramped up or down, for example before or after a maintenance phase.

[0023] In one embodiment, a glass melting furnace includes a plurality of electrodes for heating a glass melt in a production operation state, wherein a first group of electrodes of the plurality of electrodes extend into the glass melt in an area adjacent to an inner wall section, and a second group of electrodes of the plurality of electrodes extend into the glass melt in an area adjacent to an outer wall section. The first group of electrodes and / or the second group of electrodes can be designed as top electrodes. Alternatively or additionally, the electrodes can be configured as side electrodes extending from a side wall or bottom electrodes extending from a bottom. An advantage of this embodiment is that the distance between the electrodes is significantly smaller than the distance in a conventional glass melting furnace without an open space (in some cases only 1 / 4 to 1 / 3 of the conventional distance). By positioning the electrodes near the inner wall section surrounding the open space, the applied voltage can be reduced, thereby improving the safety of the glass melting furnace during operation. In addition, due to the new shape of the internal space of the furnace, the current difference existing on the surface of the glass melt relative to the raw material mixture and the cullet is smaller than that of a furnace having a furnace shape without an open space, which improves the glass quality.

[0024] In one embodiment, each electrode of the first group and / or the second group can be configured as a top electrode, so that in production operation, the electrode extends vertically into the glass melt, or extends obliquely from above (i.e. from the glass melt surface) at a small angle to the vertical (e.g., maximum 30°, preferably between 5° and 20°), and heats the glass melt from above. In one embodiment, the top electrode can additionally be configured so that the top electrode can be pivoted into and out of the interior space of the furnace. This makes it easy to replace or update any electrode. In this case, the electrodes arranged in / on the inner wall section of the side wall are accessible from the open space, and the electrodes arranged in / on the outer wall section of the side wall are accessible from the outside.

[0025] In one embodiment, the inner wall section and / or the outer wall section comprises at least one step and / or at least one recess on the corresponding hot space side. At least one recess in the inner wall section and / or the outer wall section of the side wall of the glass melting furnace can, for example, be provided for the arrangement of electrodes or the pivoting entry and / or exit of electrodes and is located in the area above the glass melt. The step can be designed so that it reduces or increases the ring width of the inner space of the furnace compared to above the step. The step can be provided due to the arrangement of fence elements made of refractory material on top of each other and can be used to arrange electrodes or influence the current in the glass melt.

[0026] In one embodiment, the diameter of the open space at least partially surrounded by the inner wall segment is at least 3 m, wherein the diameter is measured relative to the hot space side of the inner wall segment. In another embodiment, an entry and / or exit device is arranged in the open space, which device is configured to allow an operator to enter and / or exit the space in an upward and / or downward direction. Thus, the open space is large enough for an operator to work therein and to accommodate the above-mentioned entry and / or exit device (e.g., stairs, ladders, lifting platforms with guides, etc.). The entry and / or exit device is provided for occupational safety reasons so that an operator can quickly reach a safe place in the event of a problem.

[0027] In one embodiment, the interior space of the furnace is covered at the top by a rotating top plate, which basically comprises the shape of an annular disk or annular disk segment, and is preferably configured as a suspended rotating top plate. The use of a rotating top plate in the above-mentioned form makes it possible to simply cover the interior space of the furnace at the top, so that heat losses and the release of exhaust gases and / or dust can be avoided or reduced. At the same time, the rotating top plate configured to rotate through at least 90° allows the raw material mixture and / or broken glass to be easily and evenly fed into the glass melt in an easily controlled manner. Even in an embodiment in which the glass melting furnace includes an interior space volume of the furnace in the shape of a hollow body segment (i.e., not completely enclosed), the rotating top plate can also be designed as a complete annular disk to ensure that the interior space of the furnace is covered at any rotational position.

[0028] The outer wall section of the side wall of the glass melting furnace can be supported by an external steel structure arranged on the cold space side of the outer wall section. In one embodiment, the inner wall section can be additionally supported by an internal steel structure arranged on the cold space side of the inner wall section. The internal steel structure and the external steel structure support the side wall. In addition, the external steel structure and the internal steel structure (if applicable) can each include an annular track element on its top side. The corresponding track elements are used to support and guide the rotating top plate, wherein the rotating top plate includes at least two, preferably at least three corresponding wheels for each track, which roll along the corresponding track elements. The embodiment in which the track element is also arranged on the internal steel structure and at least two corresponding wheels are arranged on the rotating top plate has the following advantages: this provides additional support for the rotating top plate in the area of ​​the open space, so that the stability and safety of the rotating top plate are significantly improved.

[0029] In one embodiment, the glass melting furnace is sealed in the region of the outer wall sections and, for example, also in the region of the inner wall sections by means of a skirt (collar) which extends downwardly from the rotating top plate in the vertical direction and engages in a guide containing a sealing material, for example sand. The guide can be arranged on the top side of the outer steel structure and, in one embodiment, additionally on the top side of the inner steel structure, in each case in a substantially horizontal direction close to the corresponding rail element.

[0030] In one embodiment, the supply device and the rotating top plate are configured so that the raw material mixture and / or broken glass are supplied to the glass melting furnace through at least one corresponding opening in the rotating top plate. The supply can also be carried out, for example, by two or more openings arranged adjacently in the radial direction of the rotating top plate, which makes the raw material mixture and / or broken glass more evenly distributed on the surface of the glass melt. In another embodiment, at least two groups of openings positioned adjacently in the radial direction can be provided for supplying the raw material mixture and / or broken glass, which further makes the distribution uniform and optionally reduces the rotation angle required to rotate the rotating top plate. For example, the supply device can be configured so that at least one static storage container for the raw material mixture and / or broken glass is provided above the glass melting furnace, and the raw material mixture and / or broken glass are supplied from the storage container to the storage container movable with the rotating top plate at a properly coordinated time by means of a metering device. For example, when the movable storage container is located below the static storage container during the rotation of the rotating top plate, the raw material mixture and / or broken glass can be supplied in sufficient quantity. Alternatively, a flexible supply pipe may be provided, which connects the outlet of the metering device to the inlet of a storage container, which can be moved with the rotating top plate during its rotation. The raw material mixture and / or cullet is then further distributed to the openings in the rotating top plate from the storage container that can be moved with the rotating top plate by means of a further conveying and / or dosing device (e.g. a vibrating conveyor). If at least two groups of openings are provided, the openings in one group are arranged offset in the radial direction relative to the openings in the other group, so that the surface of the glass melt can be uniformly provided with the supplied raw material mixture / cullet.

[0031] In one embodiment, the glass melting furnace is provided with a plurality of electrodes for heating the glass melt, wherein the number of electrodes required for heating the glass melt in production operation and the power supply thereof are determined based on the melting and refining energy required for the predetermined glass output and the required glass quality. For this purpose, the current density (which should not exceed 1.5 A / cm2) on the surface of the corresponding electrode is 2 Up to 2A / cm 2 ) can be used as a boundary condition parameter. In addition, the current carrying capacity of the electrode holder system should not exceed about 3,600A.

[0032] Since the electrodes are arranged on the inner wall segments and the outer wall segments, the electrodes (e.g. rotating top electrodes) are for example positioned on at least two concentric circles or circular lines (as seen in a horizontal cross section) and are electrically connected to each other in a manner not exceeding a voltage of 500 V (for safety reasons) and a current of 3,600 A. The outer (larger) circle / line is located at a radial distance of 150 mm to 800 mm, typically 330 mm, from the inwardly facing hot space side of the outer wall segments, while the inner (smaller) circle / line is arranged at a distance of 120 mm to 800 mm, typically 330 mm, from the inwardly facing (i.e. towards the inner space of the furnace) hot space side of the inner wall segments.

[0033] For the energy supply of the electrodes, an energy supply device is provided which implements a circuit for uniform and symmetrical loading of the electrodes. A suitable circuit maps the arrangement of the pointers in the vector diagram to a geometrically similar arrangement of the electrodes in the corresponding new glass furnace. The number and arrangement of the pointers in the vector diagram results from the number and configuration of the transformers provided in the power supply. These can be designed in different circuits, for example:

[0034] Scott-T circuit - here the number of electrodes connected is a multiple of 4,

[0035] Interconnected three-phase system - here the number of connected poles is a multiple of three,

[0036] Open three-phase system – Here the number of poles connected is a multiple of 6.

[0037] The open three-phase system offers advantages in terms of lower stress on the melting electrodes and is therefore the preferred choice.

[0038] Particularly in open three-phase systems, further variations are possible in different connection modes of the primary side of the transformer, in particular, here both delta and star connections are possible. These connections can also be combined.

[0039] Furthermore, it is conceivable to divide the electrodes arranged in the inner space of the furnace into two or more sections of the inner space of the furnace. In this case, the electrodes of each section form their own heating circuit.

[0040] In a glass melting furnace comprising an interior space of the furnace having the shape of a hollow body segment, the energy supply of the electrodes is adjusted accordingly.

[0041] The above-mentioned object is also achieved by a system consisting of two of the above-mentioned glass melting furnaces, wherein the first glass melting furnace and the second glass melting furnace are positioned adjacent to each other so that the first glass melting furnace and the second glass melting furnace form a common open space, wherein, for example, the first glass melting furnace and the second glass melting furnace are configured so that glass melts with different compositions can be produced therein.

[0042] The above-described system has the advantages already described above with respect to (one) glass melting furnace. In addition, the system allows the simultaneous production of two different types of glass with relatively low space requirements. Alternatively, a glass melt having essentially the same composition can be produced in the two glass melting furnaces, and the produced glass melt can be brought together in the flow direction of the glass after being discharged through a corresponding outlet opening arranged in each glass melting furnace, and homogenized and further processed. It goes without saying that each of the two glass melting furnaces comprises an interior space of the furnace, which interior space has a mold corresponding to a segment of the above-described hollow body, i.e., for example, covering an angle of at least 120° in the horizontal direction, for example an angle between 120° and 160°. In terms of a horizontal cross section, the interior space of each glass melting furnace comprises an annular segment, wherein the other parameters of the glass melting furnaces can preferably be implemented similarly to a glass melting furnace in the form of a complete hollow body.

[0043] The two glass melting furnaces share the above-mentioned open space, which leads to excellent space utilization, wherein the inner wall section of the side wall of each glass melting furnace surrounds a part of the circumference of the open space. The two glass melting furnaces can be arranged adjacent to each other at the same height or arranged with an offset in the vertical direction. The two glass melting furnaces are arranged adjacent to each other at the same height, which means that their bottoms and / or side walls are arranged at substantially the same height in the horizontal direction. Alternatively, the two glass melting furnaces (e.g., their bottoms and / or side walls) can be arranged slightly offset from each other in the vertical direction. For example, the internal spaces of the furnaces of the two glass melting furnaces can have different heights.

[0044] The advantage of the above system is that the open space inside is accessible not only from above and below, but also through the space between two adjacently arranged glass furnaces.

[0045] Analogously to the embodiment with a single glass melting furnace, the two glass melting furnaces can be covered at the top by means of a rotating roof as described above. In this case, it is advantageous if at least one separate opening and a corresponding separate supply device for supplying a raw material mixture and / or cullet is provided for each of the two glass melting furnaces. This is particularly advantageous if glasses with different compositions are produced in the two glass melting furnaces.

[0046] The object of the present invention is also solved by a glass melting device, which comprises at least one glass melting furnace or system as described above, wherein the glass melting device also comprises a supply system for supplying a raw material mixture and / or cullet and an energy supply device for a plurality of electrodes, wherein the energy supply device is connected to each electrode. The glass melting device has the advantages of the glass melting furnace described above.

[0047] The above object is further solved by a method for manufacturing the above glass melting furnace, comprising the following steps:

[0048] Providing guardrail elements for the side walls of glass furnaces,

[0049] The fence element is arranged and fixed on or at the bottom of the glass melting furnace so that the side wall forms an inner wall section and an outer wall section positioned relative to the inner wall section, so that the hot space side of the inner wall section facing the inner space of the furnace and the hot space side of the outer wall section facing the inner space of the furnace basically have the shape of the inner shell surface and the outer shell surface of a hollow body or a corresponding hollow body section, the hollow body is, for example, a hollow cylinder or a hollow prism, and the inner wall section at least partially surrounds a through open space corresponding to the hollow space.

[0050] By means of the above method, the above glass melting furnace can be constructed in a simple and cost-effective manner. As mentioned above, the fence elements can be arranged adjacently and, if necessary, on top of each other. The fence elements are preferably fixed by means of the above inner and outer steel structures. The materials that can be used for the fence elements have also been indicated above.

[0051] As shown by the corresponding simulation, the above glass melting furnace is suitable for a glass production range of 150 tons / day to 1200 tons / day. Based on the simulation and various tests, the following parameters of the above glass melting furnace were also determined (see Figure 2a and Fig.10 ). The diameter of the outer wall section of the side wall relative to the hot space side (hereinafter referred to as the outer diameter DA) can be, for example, between 10m and 30m. The diameter of the hot space side of the inner wall section of the side wall (hereinafter referred to as the inner diameter DI) can be, for example, between 3m and 12m. The ring width RB can be, for example, between 2m and 10m. The glass liquid level depth T can be, for example, between 1.2m and 3.5m. Therefore, the internal space of the furnace (in the vertical direction) has a greater height. The melting surface area (the surface area of ​​the glass melt in the production operation state) can be, for example, between 100m 2 and 400m 2 between.

[0052] The novel glass melting furnace can be used for soda-lime glass, borosilicate glass, neutral glass or other types of glass.

[0053] The invention is explained below with reference to embodiments and with reference to the attached drawings.All features described and / or depicted represent the invention individually or in any combination, even independently of their grouping in the claims or their cross-references.

[0054] The following figure schematically shows:

[0055] Figure 1A perspective view of a first embodiment of a glass melting furnace is shown, partially cut away from the side,

[0056] Figure 2a , Figure 2b Shown according to Figure 1 Horizontal cross section of an embodiment ( Figure 2a ) and the vertical cross section of the inner wall segment ( Figure 2b ),

[0057] Figure 3 Shown according to Figure 1 A vertical cross-section of an embodiment of;

[0058] Figure 4 Shown according to Figure 1 Another perspective view of an embodiment of the invention partially cut away from the side,

[0059] Figure 5 Shown according to Figure 1 Another perspective view of an embodiment of the invention partially cut away from the side,

[0060] Figure 6 The top electrode is shown in two positions according to Figure 1 A vertical partial cross-section of an embodiment of;

[0061] Figure 7 shows a vertical cross section through the upper region of the side wall of a second embodiment of a glass melting furnace and through the rotating roof,

[0062] Figure 8 shows a vertical cross section of a third embodiment of a glass melting furnace,

[0063] Fig. 9 A perspective view of a fourth embodiment of a glass melting furnace is shown, partially cut away from the side,

[0064] Fig.10 Shown according to Fig. 9 A vertical cross-section of an embodiment of;

[0065] Fig.11 A perspective view of an embodiment of a system showing two glass melting furnaces viewed from the side without covers,

[0066] Fig.12 Shown is a side view of the case with a cover Figure 1 A system perspective,

[0067] Fig.13 shows a perspective view of a fifth embodiment of a glass melting furnace viewed from the side without a cover;

[0068] Fig.14A horizontal cross section of a sixth embodiment of a glass melting furnace is shown, illustrating the interconnection of the electrodes of this embodiment.

[0069] like Figures 1 to 6 The first embodiment of the glass melting furnace 10 is shown in Figure 1 , Figure 4 and Figure 5 1 is shown partially cut away so that the interior space 11 of the furnace is visible. Figure 2a As shown, the inner wall section 15 of the side wall and the outer wall section 16 of the side wall extend around the inner edge and the outer edge of the annular disk-shaped bottom 13, respectively, and are partially straight but approximately circular in shape. The interior space 11 of the furnace is covered at the top by a suspended rotating top plate 18. The inner wall section 15 of the side wall of the interior space 11 of the furnace surrounds a vertically extending through-open space 19, in which an entry and / or exit device for operators is arranged in the form of a spiral staircase 20. The electrode 17 extends into the glass melt 12 through the opening 15a in the inner wall section 15 and the opening 16a in the outer wall section 16, which can be Figure 3 , Figure 4 and Figure 5 From Figure 2 and Figure 3 It can also be seen that the glass melting furnace 10 also includes an outlet opening 13a in the region of the bottom 13, which outlet opening 13a has a width of, for example, 250 mm to 1200 mm and a height of, for example, 200 mm to 900 mm, through which the molten glass is discharged. The height is measured from the bottom of the outlet opening or channel to the top of the glass melting furnace 13. After the outlet opening 13a, the molten glass enters the channel 14a, the vertical pipe 14b and the regulating pipe 14c, where the glass melt is homogenized. The width of the regulating pipe 14c can be, for example, between 250 mm and 3,000 mm, and the regulating pipe 14c includes a glass level depth in the range between 150 mm and 650 mm, wherein the exemplary dimensions are related to the dimensions shown in the table below for variant 5. The homogenized glass melt can then be processed, for example, into container glass.

[0070] Regardless of the specific structure of the inner wall section 15 and the outer wall section 16 of the side wall, the bottom 13 and the rotating top plate 18, Figure 1 and Figures 3 to 6As can be seen in the figure, the interior space 11 of the furnace surrounded by the bottom 13, the inner wall section 15, the outer wall section 16 and the rotating top plate 18 has the shape of a hollow cylinder. The hot space side 15b of the inner wall section 15 facing the glass melt 12 or the interior space 11 of the furnace and the hot space side 16b of the outer wall section 16 facing the glass melt 12 or the inner wall section 16 basically have the shape of the inner shell surface and the outer shell surface of the hollow cylinder. The inner wall section 15 and the outer wall section 16 of the side wall are held by means of an inner steel structure and an outer steel structure, which will be explained in more detail using the second embodiment of the glass melting furnace. This is explained in detail in the figure. Figures 1 to 5 Not shown.

[0071] Each electrode 17 located on the inner wall section 15 of the wall extends through an opening 15a in the wall into the interior space of the furnace and from above into the glass melt 12. The electrodes 17 are similarly located on the outer wall section 16 of the wall. In this case, as Figure 6 As shown, each electrode 17 is configured so that it can be pivoted between a first position indicated by a solid line and a second position indicated by a dashed line. In the first position, the electrode 17 is in a working state, wherein the electrode supplies thermal energy to the glass melt 12 due to the Joule effect in a production operation state. In particular, Figure 2a And based on the parameters of the novel glass melting furnace given above, it can be seen that the distance between the opposing electrodes 17 of the inner wall segment 15 of the wall and the opposing electrodes 17 of the outer wall segment 16 is significantly smaller than the distance between the opposing electrodes of the outer wall segment 16, which is comparable to the distance between the electrodes in a conventional cylindrical or prismatic glass melting furnace (without open space). Therefore, the required voltage can be reduced and the flow in the glass melt and on the surface of the glass melt can be better controlled. In the operating state, each electrode is arranged relative to the vertical direction 17a (see Figure 3 ) are slightly inclined (e.g. at an angle α of 5° to 20°), which facilitates the pivoting of the electrodes in and out. Specifically, this embodiment comprises twelve electrodes 17 of the inner wall section 15 of the wall and twenty-four electrodes 17 of the outer wall section 16. The glass melting furnace of the first embodiment operates according to the cold top principle.

[0072] The rotating roof 18 (in the form of an annular disk and sealingly isolating the interior space 13 of the furnace at the top from heat losses, dust and exhaust gases, wherein the dust and exhaust gases are sucked into the filter system by a slight vacuum) comprises four openings 18a, which are located adjacently in the radial direction and through which the raw material mixture and / or cullet are supplied to the interior space 11 of the furnace, in particular to the surface of the glass melt 12. The rotating roof is configured as a suspended rotating roof and is rotatably fixed on its top side to a steel frame extending on the top side of the glass melting furnace 10.

[0073] The supply device comprises a stationary storage container 23 with a metering device. The stationary storage container 23 is connected to a storage container 24 via a flexible supply pipe 25, which connects the stationary storage container to the rotating top plate 18 when the rotating top plate 18 moves, and the raw material mixture and / or cullet are conveyed from the storage container 23 to the rotating storage container 24 in a quantitative manner from the flexible supply pipe 25 from the metering device. The raw material mixture and / or cullet enters a screw conveyor or a vibrating conveyor 27 from the first storage container 24 rotating with the rotating top plate 18, and is conveyed by the screw conveyor or the vibrating conveyor 27 via a further storage container 28 rotating in the same direction through a through opening 18a by means of a small vibrating conveyor into the interior space 11 of the furnace and onto the surface of the glass melt 12. The rotational movement of the rotating top plate 18 about the rotation axis extending approximately in the region of the spiral staircase 20 causes a (cold) layer of the raw material mixture and / or cullet to be continuously applied to the entire surface of the glass melt 12 located in the interior space 11 of the furnace. Two or more such supply devices can be distributed on the surface of the rotating top plate 18, wherein the rotating top plate also includes a group of additional openings 18a. Preferably, the additional openings 18a are arranged radially offset relative to the other openings to achieve a better distribution of the raw material mixture and / or cullet on the surface of the glass melt 12.

[0074] The spiral staircase 20 allows operators to safely enter and leave the open space 19. The spiral staircase 20 (which can also be designed as a ladder) is arranged in the center of the substantially cylindrical open space 19. The longitudinal axis of the spiral staircase can extend parallel to the longitudinal axis of the substantially cylindrical open space or coincide with the open space. Figure 6 In the process shown in FIG. 1 , in the open space 19 , an operator can pivot the electrode 17 arranged in the inner wall section 15 into or out for maintenance and / or replacement.

[0075] The inner wall section 15 and the outer wall section 16 consist of barrier elements which are arranged above and adjacent to each other. Figure 2b A vertical cross section of a lower row of wider cuboid fence elements 15c, a middle row of narrower cuboid fence elements 15d and an upper row of L-shaped fence elements 15e is shown. The outer wall section 16 is substantially similarly constructed. In the manufacture of the glass melting furnace 10, these fence elements 15c, 15d and 15e are arranged adjacent to or on top of each other as shown, attached to or in close proximity to the bottom 13 and held by a steel structure as described above.

[0076] The following design variants are shown based on a method similar to the first embodiment (see also Figure 2a and Fig.10) is a possible realization of the simulation of a glass melting furnace, wherein the dimensions are all measured relative to the corresponding hot space side. For the further embodiments explained below, such simulations can also be performed similarly.

[0077]

[0078]

[0079] According to the present invention, further scale-up of the glass melting furnace to a glass output of 1,200 tons per day can similarly be achieved by correspondingly increasing the inner diameter, outer diameter and ring width.

[0080] In the following, with the help of Figure 7 The second embodiment of the glass melting furnace 10a shown in the figure explains the construction of the glass melting furnace with respect to the steel structure in more detail. The inner wall section 15 includes an inner steel structure 35, and the outer wall section 16 includes an outer steel structure 36, which each holds and fixes the fence elements 15c, 15d and 15e. Circular guide rails 35a, 36a are respectively arranged on the upper end faces of the inner steel structure 35 and the outer steel structure 36, on which rollers 18c are guided so that the rotating top plate can rotate 360° in a first rotation direction and in the opposite rotation direction. The rollers 18c are connected to the steel structure 38 of the rotating top plate 18. In addition, the steel structure 38 of the rotating top plate 18 includes two annular sealing skirts 18d, which have sealing edges, wherein each sealing skirt 18d is guided in a sealing manner in a circular sealing groove 35b, 36b filled with sand. The sealing grooves 35b, 36b are arranged on the upper end faces of the inner wall section 15 or the outer wall section 16.

[0081] exist Figure 7 In the embodiment shown, three through-openings 18 a are arranged in the rotating top plate 18 , which three through-openings 18 a are used to feed the raw material mixture and / or cullet.

[0082] Figure 8 A third embodiment of a glass melting furnace 10b is shown, which is provided with two mutually opposite outlet openings 13a in the bottom 13 of the glass melting furnace. By using two outlet openings 13a, the glass production can be significantly increased.

[0083] Fig. 9 and Fig.10 The fourth embodiment of the glass melting furnace 10c shown comprises steps 45, 46 in the region of the inner wall section 15 and the outer wall section 16, respectively. The steps 45, 46 are configured for arranging side electrodes 47, wherein the step width b is at least 700 mm. The steps 45, 46 can have, for example, a height h of 1 m above the bottom 13. Heating by means of the side electrodes 47 represents an alternative heating option to heating by means of the top electrodes. Fig.10Also shown is a glass melt and a (cold) layer of raw material mixture and / or cullet 42 located on the glass melt. A rotating top plate 18 with an opening 18a for feeding raw materials is also depicted. Similar to the top electrode described above, the side electrode 47 extends into the glass melt 12 at a small angle (0° to 20°) inclined relative to the vertical direction. The side electrodes can also be replaced and maintained, and the side electrodes can be approached from the outside or from the open space 19. It should also be noted that the side electrodes 47 can be positioned closer together due to the central, vertically extending open space 19. This allows the required voltage to be reduced and the melting and refining process to be carried out in a more controlled manner. In addition, the electrodes are easily accessible from the outside or from the open space 19.

[0084] In the above-described embodiment, the inner wall section 15 is arranged concentrically in the outer wall section 16. A non-concentric arrangement is also conceivable.

[0085] Fig.13 Another embodiment of a completely encircling glass melting furnace 310 is shown, wherein the inner wall segment 315 and the outer wall segment are configured together to form an interior space 311 of the furnace, which has the shape of a hollow prism (more precisely: a 6-sided hollow prism). Therefore, the hot space sides 315b, 316b of the inner wall segment 315 and the outer wall segment 316 form the inner shell surface and the outer shell surface of the hollow prism. The glass melting furnace 310 also includes two opposite outlet openings 313a located in the outer wall segment, which are located directly above the bottom 313. The inner wall segment 315 completely surrounds the open space 319. The inner wall segment 315 and the outer wall segment 316 are each composed of 6 straight wall segments, wherein the inner wall segment 315 is concentrically arranged in the outer wall segment 316. The reference numerals used in the first to fourth embodiments are similarly used for this embodiment, but only increased by 300. Therefore, please also refer to the above explanation about the first embodiment. The glass melting furnace 310 may also include an annular rotating top plate with openings for feeding the raw material mixture / cullet (as in the first embodiment), however, for the sake of clarity, this is not shown here. The electrodes are depicted very schematically, and the glass melting furnace 310 includes twelve top electrodes mounted in pairs of two on the inner wall section 315 and twenty-four top electrodes also mounted in pairs of two on the outer wall section 316.

[0086] like Fig.144. As shown, the interconnection of the electrodes 417 is explained with reference to another embodiment of a glass melting furnace 410. The reference numerals used in the first to fourth embodiments are similarly used for this embodiment, however, only 400 is added. Therefore, reference is also made to the explanation of the first embodiment described above. This embodiment includes a hollow cylindrical interior space 411 of the furnace, which is laterally defined by an outer wall segment 416 and an inner wall segment 415 surrounding an open space 419. Six top electrodes 417 are located in the region adjacent to the inner wall segment 415, and twelve top electrodes 417 are located in the region adjacent to the outer wall segment 416.

[0087] In this embodiment, a power supply device (not shown) is provided, which includes three transformers, which supply power to a total of eighteen electrodes 417. The eighteen electrodes are divided into three groups of six electrodes each, and each group is assigned to a transformer, wherein an open three-phase system is used. The two transformers are connected in a triangle on the primary side (offset by 60°, the first triangle connection consists of Fig.14 The first transformer is shown in Figure 1 as a star connection (indicated by the dotted line in Figure 1 and the second delta connection is indicated by the dashed line), wherein the delta connections each include the opposite electrodes 417 of the inner wall segment 415 and the outer wall segment 416. In addition, one transformer is designed as a star connection (see the circuit marked by the dotted line), wherein the star connection only includes the electrodes arranged on the outer wall segment 416. Since the geometrical / mechanical arrangement of the electrodes in the glass melting furnace follows the position of the pointer in the electrical pointer diagram, this results in a uniform current load on all electrodes. In addition, since the distances between the connected electrodes / "heating partners" are not too long, this leads to manageable values ​​of the operating voltage / secondary voltage.

[0088] In order not to exceed the above limits on electrode current density and electrode current per top electrode, it is generally possible (i.e. also for other embodiments) to install two (rather than one) top electrodes positioned closely adjacent and electrically connected in parallel. This can double the number of electrodes of this embodiment to 36. The top electrodes closely adjacent to each other and connected in parallel together electrically form a kind of "virtual electrode".

[0089] Finally, in Fig.11 and Fig.12 1 shows an embodiment of a system including two glass melting furnaces 110, 210, which are arranged adjacent to each other in such a manner that they include a common open space 119. The electrodes arranged in the two glass melting furnaces 110, 210 are not shown, but are arranged on the inner wall sections and the outer wall sections in the same manner as in the above-described embodiment. The reference numerals used in the first to fourth embodiments are used in the same manner for this embodiment, however, only 100 and 200 are added, respectively. Please refer to the above description of the first embodiment.

[0090] The interior spaces 111, 211 of the furnaces are formed by respective bottoms 113, 213 and side walls, which consist of inner wall sections 115, 215, outer wall sections 116, 216 and intermediate wall sections 140, 240 located therebetween. An outlet opening 113a, 213a is located in the bottom 113, 213 of each glass melting furnace 110, 210, through which the molten glass is discharged. Between the two glass melting furnaces, a gap 142 is provided on both sides, through which an operator can enter the open space 119. The two interior spaces 111, 211 of the furnaces are closed at the top by a rotating top plate (in the shape of an annular disk). The rotating top plate 118 comprises two groups of four and five openings 118a, respectively, which are located adjacent to each other in the radial direction, and through which the raw material mixture and / or the cullet can be discharged in a manner similar to that of the rotating top plate 118. Figure 1 The electrodes are not shown here, but they can be designed in a manner similar to the above-described embodiments.

[0091] The interior spaces 111, 211 of the furnace are each in the shape of a hollow cylinder segment, which does not extend around the entire circumference of a complete hollow cylinder but only on a portion of the circumference. In other words, each interior space of the furnace covers an angular range β of, for example, about 150° in the horizontal direction. The hot space sides 115b, 215b of the inner wall segments 115, 215 facing the interior space 111, 211 of the furnace or facing the glass melt and the hot space sides 116b, 216b of the outer wall segments 116, 216 facing the interior space 111, 211 of the furnace or facing the glass melt are configured as inner side surface segments and outer side surface segments of a hollow cylinder.

[0092] The system of two glass melting furnaces arranged adjacent to the central open space 119 makes it possible to simultaneously manufacture glass products with different compositions. Accessibility to the inner wall sections 115, 215 of the respective glass melting furnaces 110, 210 is easily achieved via two gaps 142 connected to the inner open space 119. The two glass melting furnaces can also be used to produce glass of the same composition, in which case the discharged glass can be brought together in the flow direction after the outlet openings 113a, 213a.

[0093] The glass melting device according to the invention allows expansion to a glass output of up to 1,200 tons per day in production operation, wherein two glasses with different compositions can also be produced simultaneously. In order to better control the flow in the glass melt and reduce the distance, the electrodes can be introduced into the glass melt from above, from the side or from below at or through the inner wall section 15, 115, 215, 315 surrounding the open space 19, 119, 319 or at or through the outer wall section 16, 116, 216, 316 from above, from the side or from below. As a result, the required voltage can be reduced, thereby increasing the safety of the personnel operating the glass melting device.

Claims

1. A glass melting furnace (10, 10a, 10b, 10c, 110, 210, 310, 410) for fully electrically heating a glass melt (12) in a production operation state, the glass melting furnace having side walls made of refractory material, the side walls laterally surrounding an interior space (11, 111, 211, 311, 411) of the furnace, wherein: In a production operation state, the glass melt (12) is arranged in the interior space of the furnace, wherein the side wall comprises an inner wall section (15, 115, 215, 315, 415) and an outer wall section (16, 116, 216, 316, 416) located opposite to the inner wall section, wherein a hot space side (15b, 115b, 215b, 315b) of the inner wall section (15, 115, 215, 315, 415) facing the interior space of the furnace and a hot space side (15b, 115b, 215b, 315b) of the outer wall section (16, 116, 216, 316, 416) facing the interior space of the furnace The hot space side (16b, 116b, 216b, 316b) of the furnace (16, 216, 316, 416) facing the inner space of the furnace basically has the shape of an inner shell surface and an outer shell surface of a hollow body, the hollow body having a through hollow space or a corresponding hollow body segment, wherein the hollow body is, for example, a hollow cylinder or a hollow prism, wherein the inner segment (15, 115, 215, 315, 415) at least partially surrounds a through open space (19, 119, 319, 419) corresponding to the hollow space.

2. The glass melting furnace according to claim 1, characterized in that: The glass melting furnace comprises a plurality of electrodes (17, 47, 317, 417), wherein the plurality of electrodes (17, 47, 317, 417) heat the glass melt in a production operation state, wherein a first group of the plurality of electrodes extends into the glass melt (12) in an area adjacent to the inner wall section (15, 115, 215, 315, 415), and a second group of the plurality of electrodes extends into the glass melt (12) in an area adjacent to the outer wall section (16, 116, 216, 316, 416).

3. A glass melting furnace according to any one of the preceding claims, characterised in that The glass melting furnace is constructed such that it can be operated according to the cold top principle.

4. A glass melting furnace according to any one of the preceding claims, characterised in that The inner wall section and / or the outer wall section comprises at least one step (45, 46) and / or at least one recess (15a, 16a) on the respective hot space side.

5. Glass melting furnace according to any one of the preceding claims, characterized in that The open space (19, 119, 319, 419) at least partially surrounded by the inner wall section has a diameter of at least 3 m.

6. Glass melting furnace according to any one of the preceding claims, characterized in that An entry device and / or exit device (20) is arranged in the open space (19, 119, 319, 419) and is configured to allow an operator to enter and / or exit in an upward and / or downward direction.

7. A glass melting furnace according to any one of the preceding claims, characterised in that The angle (β) covered by the hollow body segment in the horizontal direction is at least 120°.

8. Glass melting furnace according to any one of the preceding claims, characterized in that The glass melting furnace comprises at least one outlet opening (13a, 113a, 213a, 313a), which is located in the area of ​​the bottom (13, 113, 213, 313) of the interior space of the furnace or in the area of ​​the outer wall section (16, 116, 216, 316) of the side wall near the bottom of the interior space of the furnace.

9. A glass melting furnace according to any one of the preceding claims, characterised in that The interior space of the furnace is covered at the top by a rotating roof (18, 118), which essentially has the shape of an annular disk or an annular disk segment and is preferably configured as a suspended rotating roof.

10. The glass melting furnace according to claim 8, characterized in that: The supply device and the rotating top plate (18, 118) are configured so that the raw material mixture and / or cullet are supplied into the glass melting furnace through at least one corresponding opening (18a, 118a) in the rotating top plate.

11. A glass melting furnace according to any one of the preceding claims, characterised in that Each electrode (17) in the first group and / or the second group is configured so that, in a production operation state, the electrode extends from above into the glass melt (12) vertically or at a small angle (α) to the vertical direction (17a) and heats the glass melt from above, and the electrode (17) is preferably configured so that the electrode (17) can pivot into and out of the interior space of the furnace.

12. A glass melting furnace according to any one of the preceding claims, characterised in that The glass melting furnace is provided with a plurality of electrodes (17, 47, 317, 417) for heating the glass melt, wherein the number of electrodes required for heating the glass melt and their energy supply under production operation are determined based on the melting and refining energy required for the predetermined glass output and the required glass quality.

13. A glass melting furnace according to any one of the preceding claims, characterised in that The inner wall section (15) is held by means of an inner steel structure (35) arranged on the cold space side of the inner wall section, and the outer wall section (16) is held by means of an outer steel structure (36) arranged on the cold space side of the outer wall section.

14. A system having two glass melting furnaces (110, 210) according to any one of the preceding claims, wherein the first glass melting furnace (110) and the second glass melting furnace (210) are positioned adjacent to each other so that the first glass melting furnace (110) and the second glass melting furnace (210) form a common open space (119), wherein preferably, the first glass melting furnace and the second glass melting furnace are configured so that glass melts with different compositions can be produced in the first glass melting furnace and the second glass melting furnace.

15. A glass melting device having at least one glass melting furnace (10, 10a, 10b, 10c, 110, 210, 310, 410) according to any one of claims 1 to 13 or having a system according to claim 14, wherein: The glass melting device further comprises a supply system for supplying a raw material mixture and / or cullet and an energy supply device for the plurality of electrodes, wherein the energy supply device is connected to each electrode.

16. A method for manufacturing a glass melting furnace (10, 10a, 10b, 10c, 110, 210, 310, 410) according to any one of claims 1 to 13, the method comprising the following steps: providing said side walls of said glass melting furnace with fence elements, The fence element is arranged and fixed on or at the bottom of the glass melting furnace so that the side wall forms an inner wall section (15, 115, 215, 315, 415) and an outer wall section (16, 116, 216, 316, 416) located opposite to the inner wall section, so that the hot space side (15b, 115b, 215b, 315b) of the inner wall section of the wall facing the inner space of the furnace and the outer wall section of the wall The hot space side (16b, 116b, 216b, 316b) of the inner space facing the furnace substantially has the shape of an inner shell surface and an outer shell surface of a hollow body having a through hollow space or a corresponding hollow body segment, the hollow body being, for example, a hollow cylinder or a hollow prism, and the inner wall segment (15, 115, 215) at least partially surrounds a through open space (19, 119, 319, 419) corresponding to the hollow space.

Images