Abstract: An apparatus for melting and refining a silica-based glass composition includes a vertical first reaction chamber having an input adjacent to a lower end for receiving glass-forming components. The glass-forming components are heated to elevated temperature during upward flow through the vertical first reaction chamber to form a glass precursor melt adjacent to an upper end of the vertical first reaction chamber. A vertical second reaction chamber has an input adjacent to an upper end and an output adjacent to a lower end for delivering glass melt. A cross passage connects the upper end of the vertical first reaction chamber to the upper end of the vertical second reaction chamber such that the precursor melt flows from the vertical first reaction chamber through the cross passage and then through the vertical second reaction chamber to homogenize the precursor melt.

Abstract: A precious metal structure which has an internal gas permeable membrane is described herein for a glass manufacturing vessel configured to have molten glass flow therein. The internal gas permeable membrane can be supplied with an atmosphere of gas (or gases) to control the flux of hydrogen into our out of the molten glass or otherwise improve the production of the molten glass. In this manner, the undesirable detrimental reactions that can occur at the interface of the molten glass and precious metal interface which can cause defects in the molten glass such as bubbles or solid inclusions can be stopped or at least substantially reduced.

Abstract: Delivery apparatus include an electrical circuit configured to heat a linear conduit and an elbow conduit. A first electrode can be mounted to an upstream portion of the linear conduit, a second electrode can be mounted downstream of the upstream portion, and a third electrode can be mounted to a curved segment of the elbow conduit within a footprint extension of a first passage of the linear conduit. In further examples, a delivery apparatus includes an electrical circuit with a first electrode mounted to an upstream portion of a linear conduit, a second electrode mounted to a downstream portion of the linear conduit, and a third electrode mounted to an elbow conduit. In still further examples, methods of heating molten glass include application of an electrical current such that neither a current flux through a linear conduit nor a current flux through an elbow conduit exceeds 8 amps/mm2.

Abstract: A glass melting furnace with a tank and a superstructure with a furnace crown and a total internal length (“Lg”), with a preheating zone for charging material and a combustion zone with burners. A single radiation wall is located between the preheating zone and the combustion zone such that the length of the preheating zone is between 15 and 35% of the total internal length and the length of the combustion zone is between 65 and 85% of the total internal length. The preheating zone is designed for use solely with preheating of the charging material within the furnace. The oxidation gas supply contains at least 85 volume percent oxygen and at least one outlet for the waste gases from the preheating zone is connected to the atmosphere without a heat exchanger.

Abstract: A molten glass supply apparatus including a plurality of stirring vessels (K1, K2) disposed adjacent to each other in the upstream and downstream direction along supply passage (4) for supply of molten glass having flowed out from melting furnace (2) as a molten glass supply source to forming device (3), in which among at least two agitation vessels (K1, K2) disposed adjacent to each other, at least one of upper portion and lower portion of upstream side stirring vessel (K1) is provided with an inflow opening (M1) while the other portion is provided with an outflow opening (N1), and an inflow opening (M2) and an outflow opening (N2) of the downstream side stirring vessel (K2) are provided so that upper and lower portions are the same as the upstream side stirring vessel (K1), and the outflow aperture (N1) of the upstream side stirring vessel (K1) is connected through a communicating passage (R1) to the inflow opening (M2) of the downstream side stirring vessel (K2) whose upper and lower portions are upside-do

Abstract: A front end for a glass forming operation comprises an open channel and at least one burner. The channel has at least one surface. The surface has at least one hole therein. The burner is oriented in the hole at an acute angle relative to the surface. In another embodiment of the invention, the channel has a top and a pair of sidewalls each having a surface. At least one hole is in at least one of the surfaces. The hole is at an acute angle relative to at least one surface. The burner is an oxygen-fired burner. In yet another embodiment of the invention, the top and sidewalls each have a super structure surface constructed of refractory material. The channel has an upstream end and a downstream end. At least one of the surfaces has a plurality of holes therein. The burners extend at an acute angle relative to at least one surface and in a plane extending between the upstream end and the downstream end and perpendicular to at least one surface. Oxygen-fired burners extend axially through corresponding holes.

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: A front end for a glass forming operation including an open channel and at least one burner. The channel surface has at least one burner port and a burner oriented in the burner port at an acute angle relative to the channel surface. The surface may be a top, side or end wall and the burner port is at an acute angle relative to the surface of the wall.

Abstract: A bushing including a tip plate having an orifice region including orifices to permit flow of a molten fiberizable material therethrough; a reservoir for supplying molten fiberizable material to the orifices; and a substantially planar perforated plate positioned within the reservoir generally parallel to and substantially coextensive with the orifice region of the tip plate, the perforated plate including a central region and a peripheral region surrounding the central region, each of the central region and the peripheral region of the perforated plate having a plurality of openings to permit flow of molten fiberizable material therethrough, wherein average head loss of molten material flowing through the central region of the perforated plate is greater than average head loss of molten material flowing through the peripheral region of the perforated plate.

Abstract: Apparatus for forming a cased glass stream having an inner core glass surrounded by an outer casing glass includes a first orifice for receiving core glass from a first source. A second orifice is vertically spaced beneath and aligned with the first orifice, and is surrounded by an annular chamber that communicates with the second orifice through the gap between the first and second orifices. A spout delivers casing glass from a second source through a tube to the annular chamber in such a way that glass flows by gravity from the first and second sources through the orifices to form the cased glass stream. A plurality of gas burners are disposed in the spout above the glass pool. The casing glass delivery spout is configured for improved heat transfer to, and improved heat retention within, the casing glass pool within the spout. Specifically, the glass pool surface area is enlarged, and the glass pool depth is reduced.

Abstract: A method and apparatus for making float glass, wherein the glass is stirred in the conditioning zone adjacent the entrance to the float canal so as to attenuate the glass across the entire width of the float canal.

Abstract: A glass melting furnace comprises a base structure (6) defining a melting chamber (8) an intermediate chamber (10), and a working chamber (12), in which chambers heaters are located. An opening (22) is provided into the melting chamber (8), through which batch material may be deposited on the body of molten glass in the melting chamber. Glass flows from the melting chamber (8) through an outlet (26) at a lower part thereof, which may open into the intermediate chamber (10), and flows over a wier (30) from the intermediate chamber (10) into the working chamber. Located in the outer walls of the working chamber are working outlets (34), through which blowing irons or the like tools may be entered, for a manual withdrawal of molten glass from the chamber (12).

Abstract: The device pursuant to the invention comprises means for agitation composed of at least one horizontal agitator formed from a series of essentially vertical loops extending over the entire width of the bath near the collar between the refining zone and the homogenization zone, with the horizontal agitator being moved by means that produce an elliptical motion in the horizontal plane.

Abstract: Stirring of glass of high optical quality is effected by initiating forming of the glass, such as by the float process, at relatively high temperatures immediately after the glass has been stirred. Preferably, during and/or following the stirring operation contact between the molten glass and ceramic refractories is minimized. This is preferably accomplished by providing a layer of molton metal (e.g., tin) on the bottom of the stirring chamber.

Abstract: The invention relates to a method for producing molten glass in a melting furnace 1 equipped with a tank containing a glass bath 3, where the ingredients of the glass are melted in a refining zone 10 and the molten glass flows into an adjacent conditioning zone 13.According to the invention, the current is driven to a passage 31, which is located at the common boundary of the refining zone 10 and the conditioning zone 13, this boundary or corset has a narrower width than that of the current, and the current is forced to go through the passage 31.Thus the homogeneity of the glass is increased at drawing off.

Abstract: A continuous tank-type glass melting furnace includes a melting zone into which raw materials are charged and reduced to a molten state. The molten glass then flows through a relatively narrow waist or conditioning area to refining and conditioning zones, and is then withdrawn as a continuous ribbon or sheet. Within the waist area there is provided a plurality of stirrers whose mixing and kneading action assist in homogenizing the glass as it flows through the restricted area. Each stirrer is connected to and driven by its own individual power unit so that the speed and direction of rotation of individual stirrers can be independently regulated and synchronized. Individual stirrers can also be removed and replaced with little or no interruption in operation of the remaining units.

Abstract: Method and apparatus is presented particularly suitable for blending and homogenizing a low viscosity molten additive into a relatively high viscosity host glass composition as it flows through a supply forehearth. The blending and homogenizing is performed by a rotating spiral stirrer operating within a mixing well simultaneously mixing and pumping the molten mixture therethrough. The spiral stirrer may be used separately or in concert with one or more spiral stirrers.

Abstract: Glass is melted in a furnace having a melting zone and one or more processing tanks adjacent to the melting zone. Molten glass flows from the melting zone to the processing tank through a passage. A portion of the molten glass is withdrawn from the top of the processing tank and is recirculated to the processing tank or to a separate refining zone. The furnace includes a melting section and at least one adjacent processing tank communicating with the melting section through a passage. A recirculating passage connects the top of the processing tank and the passage connecting the melting section and the processing tank. Additional means are provided to establish a recirculating flow of molten glass via the recirculating passage.

Abstract: A forehearth for feeding molten glass to a flow feeder, a set of blenders, and a set of homogenizers are spaced from each other along the length of the forehearth with three evenly spaced vertically positioned elongated plates located between the set of blenders and the set of homogenizers. The particular arrangement provides a system for eliminating, to a great extent, cords at the feeder.

Abstract: A glassmaking furnace having a melter and a refiner joined through a waist is provided with a plurality of glass stirrers positioned transversely across the intended path of glass flow through the waist. Each stirrer comprises two coaxial pipes, an inner pipe and an outer pipe, the outer pipe having a bent loop extension at one end, such that one end of the bent loop extension is in communication with the annular space between the pipes and the other end is in communication with the inner pipe. Each stirrer is provided with means for supplying a coolant to the pipes and means for rotating the stirrer in order to homogenize glass before it is fully refined by appropriate thermal conditioning in the refiner of the furnace.

Abstract: This invention relates to a fusion and casting machine for the preparation of glass buttons for analysis.The machine contains an assembly of several heaters which moves with a precession motion imparting agitation to the content of the molten materials. When the materials are fused, agitation stops, flame goes out, moulds which were intially above the crucibles move under the crucibles, and the crucibles turn over and transfer their content into the moulds where solidification takes place. Perfect glass buttons are produced: these are stable, homogeneous, flat, smooth, bubble-free and need no further processing before the anaylsis.

Abstract: In accordance with the method and apparatus of this invention, glass-forming materials are subjected to heat and agitation sufficient to form a molten glass having mostly dissolved glass-forming materials, mostly completed chemical reactions between the glass-forming materials and containing a high number of gaseous inclusions, and containing up to 50 volume percent entrapped gases. This glass appears foamy. The molten glass is transferred to a second chamber to complete melting of any unmelted sand grains remaining from the glass-forming materials, and completes the chemical reactions that remain incompleted, and to remove any remaining cords, and to reduce the foamy character of the melt to a dense molten glass which contains only small-sized gaseous inclusions.

Abstract: The present invention provides a method of melting glass, whereby in a glass melting furnace having electrodes positioned in a plurality of levels or planes the glass is melted in a vertical passage and thereafter discharged via an outlet passage at the bottom of the furnace, while the glass stream, after its upward flow, flows vertically downwards under mechanical agitation, thereafter to flow upwards for further processing or treatment. The glass stream may be additionally heated by electrical energy during its upward flow prior to the agitation.

Abstract: In a continuous, fuel-fired glass melting furnace, a pair of substantially horizontal, longitudinally extending electrodes are provided in the molten glass closely adjacent to the sides of the floating batch blanket for supplying electrically generated booster heat to the underside of the batch blanket. The electrodes extend a substantial distance into the melting zone of the furnace through the fill end wall. The electrodes also serve as physical barriers that prevent the batch blanket from drifting into contact with sidewalls of the furnace. The electrode arrangement boosts melting rates with efficient utilization of electrical energy, and avoids furnace wall erosion and unbalanced melting conditions.