Abstract: An arrangement structure for bubbling apparatuses of a furnace, comprising bubbling apparatuses disposed in a melting pool (11) of a furnace. Each bubbling apparatus comprises a bubbling tank (8) and a bubbling tube (9). The bubbling tank (8) is provided at the bottom of the melting pool (11) and disposed in recessed fashion. The bubbling tube (9) is mounted in the bubbling tank (8). The structure can efficiently enhance the physical effect of a bubbling gas on molten glass and improve the quality and production efficiency of the molten glass.

Abstract: Hydrogen may permeate into an interior space of an article in response to molten glass being in contact with the outer surface of the article. The permeation may be restricted by having a fluid in a length of the interior space. The fluid may be in contact with the inner surface of the article, the fluid may fill at least about 33% of the volume of the length of the interior space, and the fluid may provide a predetermined partial pressure of hydrogen. Features may be provided for causing the fluid to flow within the interior space.

Abstract: A method to form quartz glass ingots of ultra low contamination and defect levels by firing a high-purity quartz form as the feedstock, wherein the quartz glass ingot is free-formed on a platen rotating concentrically with the feedstock quartz article.

Abstract: A bubbler base or base body for accepting a bubbler tube that has an externally threaded section at one end of the bubbler tube. The bubbler base of this invention can be used to quickly attach the bubbler base already connected to a bubbler tube, without the need to form an internally threaded bore within a bottom clamp plate which is also referred to as a cooling plate and is conventionally known in the molding tool industry. A conventional bubbler tube can be attached to the bubbler base rather than to the bottom clamp plate or the cooling plate. The bubbler base can have an overall spool shape. An O-ring can be used to seal the bubbler base with respect to the bottom clamp plate or the cooling plate.

Abstract: A furnace for melting batch materials, including, upstream in the direction of flow of the molten materials, a zone for introducing solid batch materials, and including a submerged burner and an overhead surface burner providing a flame that touches the surface of the glass at the point where the bubble from the submerged burner emerges. This association of an overhead, especially roof-mounted, burner and a submerged burner reduces the quantity of batch stones that may be sent toward the downstream end of the furnace.

Abstract: A chamber (101, 201), for holding molten glass (113, 202) having a free surface (114, 203), includes a bellows (4, 204), a sealing ring (10, 210), and a cover (30, 50, 230). The bellows is coupled to the chamber, and the sealing ring is coupled to the bellows. The sealing ring may include one or more various devices, associated with operation of the chamber, including: an atmosphere supply tube (14, 214), an electric lead (12), a pressure differential sensor (16, 216), a thermo couple, an oxygen sensor, and/or an auxiliary port (18). The sealing ring further includes an upper opening (21) having an inner diameter (22). The cover is removably coupled to the sealing ring and extends over the sealing-ring-upper-opening inner diameter, wherein the sealing ring is disposed between the cover and the chamber. The cover may include various separately removable sections (30, 32, 34, 35, 37, 50, 52, 54).

Abstract: A stirring system for molten glass having a stirring vessel and a stirrer; and a method for homogenizing glass melts. The stirrer has a shaft and at least one stirring element, and the stirring vessel has at least two baffles extending from an inner circumferential surface. The stirring element and baffles are formed in such a way that insertion of the stirrer into the stirring vessel requires at least one translatory movement of the stirrer in relation to the stirring vessel, at least one subsequent or simultaneous relative rotation of the stirrer in relation to the stirring vessel, and a further translatory movement of the stirrer in relation to the stirring vessel. In an operating state, the stirrer is rotatable in the stirring vessel.

Abstract: Device (20) for purifying a molten material such as silicon, comprising a chamber (21) comprising a crucible (2; 15) for storing a molten material and a heating device (4) for heating the molten material contained in the crucible, the chamber being equipped with a device (22) for greatly lowering the pressure in the chamber, characterized in that it comprises at least one evaporator (10; 10, 10?) placed inside the chamber to receive part of the molten material, such that this molten material has a large interface with low-pressure vapour present in the chamber (21) to promote and accelerate the purification of the molten material.

Abstract: An apparatus for crystallization of silicon includes a crucible for containing silicon, a heating and heat dissipating arrangement provided for melting the silicon contained in the crucible and for subsequently solidifying the molten silicon, and an electromagnetic stirring device provided for stirring the molten silicon in the crucible during the solidification of the molten silicon. A control arrangement is provided for controlling the heating and heat dissipating arrangement to solidify the molten silicon at a specified solidification rate and for controlling the electromagnetic stirring device to stir the molten silicon in response to the specified solidification rate of the molten silicon such that the ratio of a speed of the molten silicon and the specified solidification rate is above a first threshold value.

Abstract: An apparatus for crystallization of silicon includes a crucible for containing silicon, a heating and heat dissipating arrangement provided for melting the silicon contained in the crucible and for subsequently solidifying the molten silicon, and an electromagnetic stirring device provided for stirring the molten silicon in the crucible during the solidification of the molten silicon. A control arrangement is provided for controlling the heating and heat dissipating arrangement to solidify the molten silicon at a specified solidification rate and for controlling the electromagnetic stirring device to stir the molten silicon in response to the specified solidification rate of the molten silicon such that the ratio of a speed of the molten silicon and the specified solidification rate is above a first threshold value.

Abstract: A method of manufacturing glass comprises a stirring step in which molten glass MG is stirred. The stirring step comprises a first stirring step and a second stirring step. In the first stirring step, the molten glass MG is stirred while being directed upward from below in a first stirred tank 100a. In the second stirring step, the molten glass MG stirred in the first stirring step is stirred while being directed downward from above in a second stirred tank 100b. The first stirred tank 100a has a first discharge pipe 110a capable of discharging the molten glass MG from the bottom of a first chamber 101a. The second stirred tank 100b has a second discharge pipe 110b capable of discharging the molten glass MG from the liquid level LL of the molten glass MG in a second chamber 101b.

Abstract: In the formation of sheet material from molten glass, molten glass is formed in a melting furnace and transported through a precious metal delivery system to the forming apparatus. Disclosed herein is a method to mitigate carbon contamination of individual components of the precious metal delivery system prior to and/or during their use. The method involves positioning an oxygen generating material within portions of a precious metal component, and may comprise one or more heat treating steps of the component in an oxygen-containing atmosphere.

Abstract: The device for manufacturing glass, in which bubble formation on precious metal components is prevented, has a precious or refractory metal wall (12, 43) at least partially surrounding a glass melt from which the glass is made, a first electrode pair (20, 21) for measuring oxygen partial pressure at an interface between the glass melt and the wall to obtain an actual value, a second electrode pair (12, 43, 20) for measuring an oxygen partial pressure in the glass melt to obtain a set point value and a regulating system (39, 45) for adjusting the oxygen partial pressure at the interface according to a comparison between the actual value and the set point value, so that the oxygen partial pressure at the interface is within a safe range.

Abstract: A heat exchanger includes headers and tubes two ends of each of which are connected with and communicate the headers. Each of fins is disposed between adjacent tubes. An end cover is formed with a center hole and fixed to a proximal end of one of the headers. A distal end of a sleeve passes through the center hole to extend into the header, and a proximal end of the sleeve is held by a proximal end surface of the end cover. A first distribution-collection tube is fixed to the sleeve and defines an open proximal end and a closed distal end passing through the sleeve to extend into the header in which openings are formed along a longitudinal direction of the distribution-collection tube in a portion thereof extended into the header. A fixing nut is screwed onto the end cover to press the proximal end of the sleeve against the proximal end surface of the end cover.

Abstract: A molten glass delivery system is modified to match it with the overflow downdraw process. A substantial number of defects not removed by the finer are diverted to the unusable inlet and distal edges of the sheet. In one embodiment, the stirring device is relocated from the outlet to the inlet of the finer. In another embodiment, the basic shape of the finer is preferably changed from a cylindrical shape to a Double Apex (or Gull Wing) shaped cross-section, whereby the apexes of the finer contain the glass that will form the unusable inlet end of the glass sheet. The finer vent or vents are preferably located at these apexes such that any homogeneity defects caused by the vents are diverted to the unusable inlet end of the glass sheet. The finer cross-section has a high aspect ratio for increased fining efficiency as compared to a cylindrical finer.

Abstract: Stirring apparatuses for stirring molten glass are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. In one embodiment, an apparatus for stirring molten glass includes a cylinder comprising a bore. A stirrer may be disposed in the bore. The stirrer may include a platinum or platinum alloy shaft coaxial with the cylinder. A plurality of impellers may project radially from the shaft into close proximity of a wall of the cylinder. Each impeller may include an arcuate distal end portion farthest from the shaft. The distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy. The stirring apparatuses reduce metal loss from the refractory metal of the stirring apparatus.

Abstract: Apparatus, which is suitable for being surrounded by molten glass, the apparatus having a shank which has at least one at least partially seamless tube consisting of an oxide dispersion-strengthened PGM material, the shank having at least one thickened portion on which an actuating device is arranged.

Abstract: The invention relates to a device for homogenizing a glass melt in a melt receptacle, wherein at least one stirring device is disposed in a melt receptacle, which comprises a stirrer shaft and a plurality of stirrer blades, and wherein a gap (16) is formed between a wall region of the melt receptacle and the stirrer blades. According to the invention, the respective stirring device causes an axial feed action in an inner stirring region between the stirrer shaft and the stirrer blades in order to feed the melt in the stirring region along the stirrer shaft. A melt flow brought about by the axial feed action seals the gap against direct passage of the melt. According to the invention, a very high gap width can be achieved, thus preventing the abrasion of materials in the region of the marginal gap. This also reduces the complexity required for adjusting the device. According to the invention, a high level of homogenization can be achieved regardless of the entry point of the inhomogeneities.

Abstract: The device for homogenizing a glass melt has a melt receptacle and at least one stirring device arranged in the melt receptacle. Each stirring device consists of a stirrer shaft and stirrer blades extending toward an inside wall of the receptacle, which are configured to produce an axial feed of the glass melt in an inner stirring region between the stirrer shaft and front ends of the stirrer blades. The melt receptacle and the stirring device are configured so that a melt flow caused by the axial feed, which is opposite to the axial feed, seals a gap formed between the inside wall and the front ends of the stirrer blades, so that the glass melt cannot flow directly through the gap to a lower axial end of the inner stirring region. The invention also encompasses a method of homogenizing a glass melt.

Abstract: Stirring apparatuses for stirring molten glass are disclosed. The method includes stirring a molten glass with a stirrer comprising a layer containing at least about 50% iridium. An apparatus comprising an iridium-containing layer is also presented. In one embodiment, an apparatus for stirring molten glass includes a cylinder comprising a bore. A stirrer may be disposed in the bore. The stirrer may include a platinum or platinum alloy shaft coaxial with the cylinder. A plurality of impellers may project radially from the shaft into close proximity of a wall of the cylinder. Each impeller may include an arcuate distal end portion farthest from the shaft. The distal end portion of each impeller consists of iridium or an iridium alloy and the remainder of the impeller consists of platinum or a platinum alloy. The stirring apparatuses reduce metal loss from the refractory metal of the stirring apparatus.

Abstract: An apparatus for crystallization of silicon includes a crucible for containing silicon, a heating and heat dissipating arrangement provided for melting the silicon contained in the crucible and for subsequently solidifying the molten silicon, and an electromagnetic stirring device provided for stirring the molten silicon in the crucible during the solidification of the molten silicon. A control arrangement is provided for controlling the heating and heat dissipating arrangement to solidify the molten silicon at a specified solidification rate and for controlling the electromagnetic stirring device to stir the molten silicon in response to the specified solidification rate of the molten silicon such that the ratio of a speed of the molten silicon and the specified solidification rate is above a first threshold value.

Abstract: In the formation of sheet material from molten glass, molten glass is formed in a melting furnace and transported through a precious metal delivery system to the forming apparatus. Disclosed herein is a method to mitigate carbon contamination of individual components of the precious metal delivery system prior to and/or during their use. The method involves positioning an oxygen generating material within portions of a precious metal component, and may comprise one or more heat treating steps of the component in an oxygen-containing atmosphere.

Abstract: The present invention is directed toward a method of reducing contamination of a glass melt in a stirring apparatus by an oxide material. The oxide material, such as platinum oxide, may be volatilized by the high temperature of the glass melt, and then condense on the inside surfaces of a stirring vessel, particularly the stirrer shaft and surrounding surfaces of the stirring vessel cover. A build-up of condensed oxide material may then be dislodged and fall back into the glass melt. Accordingly, an apparatus and method is provided that includes a heating element disposed adjacent an annular gap between the stirring vessel cover and the stirrer shaft. The heating element heats a surface of the stirring vessel cover bounding the annular gap and prevents condensation of volatile oxides that may flow through the annular gap.

Abstract: A glass melting oven for producing a glass melt in a row arrangement, having a loading opening for raw glass materials, a melting region, a refining region, a constriction, a conditioning region and an overflow into a processing unit. To remove flaws from the melt that remain visible in the end product, a method includes the steps of a) arranging a refining bench between the melting region and the beginning of the refining region; b) arranging side burners and extraction openings for flue gases between the loading opening and the refining bench; c) delimiting the constriction at both ends by end walls that leave narrow flow cross-sections above the glass melt for flue gases; and d) cooling the glass melt inside the constriction. The glass melting oven is particularly suited for producing flat glass and panels for solar elements. The oxidants for the fuels may also be preheated.

Abstract: A glass manufacturing container includes a container body and an electron donor. The container body is made of a precious metal or an alloy containing a precious metal and has an inner surface to be brought into contact with molten glass and an outer surface kept from contact with molten glass. The electron donor is electrically connected to the outer surface of the container body. The electron donor is made of an electron donating material capable of donating electrons to the container body at operating temperatures.

Abstract: The present invention provides flake having a thickness up to 350 nm, the flake being made of basalt, ceramics, alumina, graphite, a metal, a metal oxide or a combination of any two or more thereof. Equipment for manufacturing such flake is also described as is a method for the manufacture of the flake. The equipment comprises a cup mounted for rotation and for receiving molten glass. The equipment further comprises either insulating means extending at least partially around said cup or means for heating the cup while it is rotating.

Abstract: In the apparatus for producing glass reduction of reduction-sensitive components in the glass melt is reduced or preferably is prevented during the melting and/or fining processes by introducing an oxidizing agent into the glass melt. The apparatus has a melt crucible, a fining vessel, and a device for conducting oxygen and/or ozone into the glass melt in the melt crucible and/or fining vessel, in order to suppress reduction of reduction-sensitive components of the glass melt. A preferred embodiment of the apparatus has a metallic skull crucible, which includes the melt crucible and/or the fining vessel. The apparatus preferably includes a homogenization unit connected to the fining vessel to receive glass melt from the fining vessel in order to further process the glass melt after refining.

Abstract: The apparatus (300) for feeding, homogenizing, and conditioning a high viscosity glass melt for manufacturing display glass has a stirring device (110, 406), an upstream connecting part (100, 400) that connects the stirring device (110, 406) to an upstream melting and/or refining unit, and a downstream connecting part (120, 420) that connects the stirring device (110, 406) to a downstream forming or shaping device. Wall material and base material of the first and connecting parts and the stirring device (110, 406) coming in contact with the glass melt are made from a zirconium-dioxide-containing fire-resistant material containing a large amount, preferably more than 85 wt. %, of zirconium dioxide. A method of operating the apparatus to make display glass is also described.

Abstract: The present invention is directed toward a method of reducing contamination of a glass melt by oxide particulates, such as particulates of platinum oxide, which may condense on the inside surfaces of a stir chamber, particularly the stir shaft, and fall back into the glass melt. The method includes causing a flow of gas through an annular space between the shaft and the chamber cover. In one embodiment, the flow of gas through the annular space is caused by drawing a vacuum in the chamber. An apparatus for practicing the method is also provided.

Abstract: Apparatus, which is suitable for being surrounded by molten glass, the apparatus having a shank which has at least one at least partially seamless tube consisting of an oxide dispersion-strengthened PGM material, the shank having at least one thickened portion on which an actuating device is arranged.

Abstract: A method of mixing a viscous liquid comprising flowing the viscous liquid through an aperture to form a stream that falls through a free space volume by gravity. The viscous liquid may be directed through any combination of apertures. The corresponding streams of viscous liquid may be allowed to undergo fluid buckling as the streams fall, with the streams spreading the inhomogeneities and then recombining with each other, thereby mixing the viscous liquid globally and locally. A jet of gas may be directed against the falling streams to intertwine the streams, thereby mixing the viscous liquid. Alternatively, the streams may be manipulated with an electromagnetic field to create intertwining.

Abstract: A charged glass raw material B is melted in a melting tank 10 by heating with a burner 31 and by heating with electrodes 12, to form molten glass G. Then, the molten glass G flows into a tank additionally provided as a noble gas dissolving tank 20 through a throat 40. The noble gas dissolving tank 20 is provided with a noble gas dissolving device 53, and the noble gas dissolving device 53 is provided with sixteen noble gas inlets 22 for introducing a helium or neon gas supplied to a hearth through heat resistant gas introduction tubes 21 into the noble gas dissolving tank 20. Bubbles of a helium gas A having a purity of 99% are blown out from the noble gas inlets 22 in volumes such that the bubbles have an average diameter of 80 mm or less in the molten glass G.

Abstract: A molten glass delivery system is modified to match it with the overflow downdraw process. A substantial number of defects not removed by the finer are diverted to the unusable inlet and distal edges of the sheet. In one embodiment, the stirring device is relocated from the outlet to the inlet of the finer. In another embodiment, the basic shape of the finer is preferably changed from a cylindrical shape to a Double Apex (or Gull Wing) shaped cross-section, whereby the apexes of the finer contain the glass that will form the unusable inlet end of the glass sheet. The finer vent or vents are preferably located at these apexes such that any homogeneity defects caused by the vents are diverted to the unusable inlet end of the glass sheet. The finer cross-section has a high aspect ratio for increased fining efficiency as compared to a cylindrical finer.

Abstract: The invention relates to a method and a device for homogenizing a glass melt using at least one stirring means which is respectively arranged in a stirring vessel having an inlet (4) and an outlet (5), the respective stirring means having a plurality of stirrer blades (11, 20, 21) arranged spaced apart from one another along a common stirrer shaft (10). According to the invention, the stirring means and/or the device is configured in such a way that a net conveying effect of the stirring means overall from the inlet to the outlet is substantially imperceptible. The conveying effect of the stirring means overall from the inlet (4) to the outlet (5) is caused by the positioning of the stirring blades (11, 20, 21), by the geometric shape thereof and/or by the angular position of the stirring blades in the circumferential direction of the stirrer shaft (10).

Abstract: The present invention relates to a molten glass stirrer having a spiral agitating blade with through openings on a blade surface, and to technique for rotating the molten glass stirrer that is soaked in molten glass. The through openings are preferably located in a radial direction with a shaft being a center, and preferably have an elongated rectangle or a boomerang shape. According to the present invention, molten glass flow is created three-dimensionally and spirally, and the molten glass flow is cut in a substantially vertical direction to the shaft, thereby homogenizing the molten glass and avoiding defects such as striae, and therefore, high quality glass products can be manufactured.

Abstract: Bubbles of uniform diameter of 0.5 to 4 cm of gas such as helium are formed and pass into liquid such as molten glass by accumulating a sufficient volume of gas through a flow restriction into a space upstream of the point of injection at a controlled flow rate.

Abstract: A method of controlling reaction paths of glass batch components added to a resident glass melt is provided, including the steps of providing a plurality of raw material batch components according to a batch recipe, selectively combining a portion of the batch components into a first combination material having a melting temperature in a range of 60 to 90% of a resident melt temperature (K) and a viscosity3 a melt viscosity/100, and selectively combining another portion of the batch components into a second combination material having a reaction temperature in a range of 60 to 100% of the resident melt temperature, the second combination material being capable of forming an intermediate compound via a solid state reaction before reacting with the glass melt. The first and second combination materials and any remaining batch components are mixed and introduced into a glass melter.

Abstract: A gas bubbler device provides enhanced recirculation of molten glass within a glass melter apparatus. The bubbler device includes a tube member disposed within a pool of molten glass contained in the melter. The tube member includes a lower opening through which the molten glass enters and upper slots disposed close to (above or below) the upper surface of the pool of molten glass and from which the glass exits. A gas (air) line is disposed within the tube member and extends longitudinally thereof. A gas bubble distribution device, which is located adjacent to the lower end of the tube member and is connected to the lower end of the gas line, releases gas through openings therein so as to produce gas bubbles of a desired size in the molten glass and in a distributed pattern across the tube member.

Abstract: The invention relates to a meltdown device for the production of high-UV transmittive glass types, comprising a meltdown tank for a melt bath a feed opening for the supplying or laying-in of highly pure raw material for the melt bath a draw-off opening for the drawing-off of material melted in the melt tank a cover arranged above the melt tank, in which the infeed opening to the melt tank is arranged above the melt bath in the region of the cover the draw-off opening is arranged in the zone of the bottom of the melt tank a heating arrangement. The heating arrangement comprises heating elements, in particular electrodes that are arranged on the melt tank in the zone of the melt bath, as well as an agitating arrangement for stirring of the melt bath and uniform intermixing and sub-mixing into the melt of material from the mixture lying on the melt surface.

Abstract: The level of precious-metal inclusions in glass products, e.g., glass substrates for liquid crystal displays, is reduced by stirring molten glass in a stir chamber (11) under conditions such that the magnitude of the shear stress ? on the chamber's wall (19) and on the surfaces of the stirrer (13) is reduced while at the same time, the Q•E product for the system is kept high, where Q is the flow of glass through the stirring system and E is the system's stirring effectiveness.

Abstract: A method for controlling the foam produced when a molten material encounters reduced pressure in a vacuum chamber includes passing the molten material through an aging zone in the vacuum chamber in which the molten material is allowed to drain from between the bubbles of the foam and then collapsing the bubbles of the drained foam.

Abstract: The subject of the invention is a process for manufacturing compounds based on one or more silicates of alkali metals, such as Na and K and/or alkaline earth metals such as Ca, Mg, and/or on rare earths, such as Ce, optionally in the form of mixed silicates which combine alkaline-earth metals, such a Ca, with the alkali metal(s) and the rare earth(s), by conversion of silica and of halides, especially of one or more chlorides, or sulfate or nitrate, of the said alkali metals and/or of the said rare earths and/or of the said alkaline-earth metals, such as NaCl, KCl or CeCl4. The heat needed for the conversion is supplied, at least partly, by one or more submerged burners.

Abstract: An apparatus for making glass in which a glass melt is refined in a vessel with oxygen is described. It includes a melt-containing vessel (10) having a refining region (3) for refinement of the glass melt and a noble metal member for producing oxygen in the melt. The noble metal member (40) has an outer side facing the glass melt and an inner side facing away from the glass melt washed with and acted on with oxygen. Oxygen-containing bubbles are vigorously generated on the outer side of the noble metal member facing the glass melt when the inner side is washed with the oxygen.

Abstract: A molten glass pump preferably includes one or more pumps which form either a single-stage apparatus or are combined in series to form a multi-stage apparatus. The exact configuration depends on the required process pressure and the required degree of glass homogenization. Examples of the invention include an auger pump and a mixing auger pump which have varying degrees of mixing action, as well as a homogenizing pump which provides some pumping action but is primarily a homogenizer. All three pumps preferably include a centerline flow recirculation feature which remixes inhomogeneous glass into the incoming glass stream. A counter-rotating sleeve, which straightens the glass flow exiting the apparatus and provides an additional flow recirculation path, is also preferably included.

Abstract: An apparatus for making glass in which a glass melt is refined in a vessel with oxygen is described. It includes a melt-containing vessel (10) having a refining region (3) for refinement of the glass melt and a noble metal member for producing oxygen in the melt. The noble metal member (40) has an outer side facing the glass melt and an inner side facing away from the glass melt washed with and acted on with oxygen. Oxygen-containing bubbles are vigorously generated on the outer side of the noble metal member facing the glass melt when the inner side is washed with the oxygen.

Abstract: A method of preparing an object with a radially-varying property is disclosed which includes the steps of providing a preform reactor including an outer container having a bottom, an inner container installed in the outer container, the inner container having a bottom, a rotating rod installed at a position in the outer container, and a sealing member for sealing the outer and inner containers at the bottoms thereof; filling the inner container with an inner material and a space between the inner container and the outer container with an outer material wherein the outer material has a different property from the inner material; removing the inner container; and rotating the rotating rod for laminar mixing of the inner and outer materials. An apparatus for carrying out the inventive method, and objects formed in accordance with the inventive method, are also disclosed.

Abstract: The invention pertains to a stirrer apparatus for glass melts. A stirring element and a stirrer shaft are provided, each comprised of a metal or a metal alloy having a high melting point temperature. A drive shaft for the stirring element comprises a different metallic material, for example an ODS alloy on the basis of iron or nickel. The junction between the stirrer shaft and the drive shaft is located approximately in the region in which the level of the surface of the glass melt is located during use. The end portion of the drive shaft or the end portion of the stirrer shaft, which can be covered by the melt during use, are isolated by a platinum casing.

Abstract: The invention relates to a meltdown device for the production of high-UV transmittive glass types, comprising

Abstract: The invention pertains to a stirrer apparatus for glass melts. A stirring element and a stirrer shaft are provided, each comprised of a metal or a metal alloy having a high melting point temperature. A drive shaft for the stirring element comprises a different metallic material, for example an ODS alloy on the basis of iron or nickel. The junction between the stirrer shaft and the drive shaft is located approximately in the region in which the level of the surface of the glass melt is located during use. The end portion of the drive shaft or the end portion of the stirrer shaft, which can be covered by the melt during use, are isolated by a platinum casing.

Abstract: In a glass melter, a precious metal insert is used to protect a gas bubbler from corrosion at the orifice of the bubbler through which gas is injected into the melt. The use of a precious refractory metal insert at the bubbler orifice prevents the attack of molten glass on the bubbler. The precious metal is chosen from the refractory group of metals and the platinum group of metals. Preferably the precious metal from the platinum group is platinum or one of its alloys or one of ruthenium, rhodium, palladium, osmium and iridium. The precious metal from the refractory group is preferably chromium.