Abstract: The invention relates to the employment of at least one oxygen-fuel burner in a particular manner in glass melting cross-fired regenerative furnaces. By operating oxygen-fuel burners positioned in particular places in a cross-fired regenerative furnace in an appropriate manner, the glass melting can be accomplished without disrupting the flame momentum of the air-fuel burners, thereby improvidng the efficiency of the glass melting and increasing the production of the glass products.

Abstract: The invention relates to a process for melting solid glass forming ingredients in a regenerative of recuperative furnace having an upstream melting zone and a downstream fining zone comprising:a) introducing said solid glass forming ingredients into said upstream melting zone;b) heating said solid glass forming ingredients so that an interface of solid glass forming ingredients and molten glass is formed;c) providing heat sufficient to maintain the molten glass in the molten state through said downstream fining zone and sufficient to melt said solid glass forming ingredients, wherein at least a part of said heat is provided by at least one flame from at least one oxygen-fuel burner located on the roof of said furnace, the position of said at least one oxygen-fuel burner on the roof being such that the tip of its flame is directed approximately at the interface of said solid glass forming ingredients and said molten glass in an angle ranging from about 25.degree. to about 90.degree.

Abstract: A continuous glass-melting tank furnace includes a melting compartment including a melting tank having a lower part, and a superstructure equipped with heaters for receiving and melting raw batch material. Additionally included is a separate refining compartment including a refining tank and a superstructure equipped with a further heater, the refining tank having a lower part and including a transverse sill which divides the refining tank into an upstream refining cell and a downstream refining cell, each of the upstream refining cell and the downstream refining cell having respective upstream ends and downstream ends, and the further heater being arranged to heat melt in the upstream refining cell for creating a spring zone located closer to the downstream end of the upstream refining cell and a circulation of melt in the upstream refining cell which feeds the spring zone.

Abstract: The invention provides a method and apparatus for equalizing the temperature of molten glass (2) over the cross-section of a stream thereof advancing through a refractory forehearth from a glass furnace to a glass working machine. To this end, cooling air is blown downwardly to strike the mid-line of the stream, and is then evacuated upwardly from locations on either side of the mid-line, in such manner that substantial side regions of the stream surface are preserved from cooling contact with the cooling air. Apparatus for this purpose comprises refractory blocks (4a, 4b) which can be assembled to form a forehearth superstructure or roof, the blocks having hollow formations which unite on assembly thereof to form feed (11) and return (12, 13) channels for the cooling air, as well as inlet (8) and exhaust (9, 10) ducts for directing it at the molten glass and recovering it thereafter.

Abstract: Concerning the manufacture of sheet glass by the float process using, as a glass melting and refining tank furnace, a common regenerative furnace having two oppositely arranged sets of burners which are periodically alternately operated with a temporary interruption of firing operation at each reversal of firing, the invention relates to the control of the rate of feed of molten glass from the tank furnace onto a molten metal bath through a canal provided with a control tweel which can be moved upward and downward. At each reversal of firing in the furnace the tweel is temporarily lifted so as to compensate for a decrease in the volumetric rate of flow of molten glass through the canal caused by the temporary interruption of firing operation.

Abstract: A plurality of conduit segments contact on another which run vertically and transversely to the direction in which molten glass is channelled. Each segment includes at least one trough section and at least one cover section, an insulation of individual formed bodies, and an external casing. The segments are coupled together on support beams and may have removable insulation at joints to facilitate inspection.

Abstract: A chamber (1) for the thermal treatment of objects comprises in its interior heating means (3, 4) and means (5) to support the objects (2) to be treated, the walls of this chamber comprising a thermal insulating lining, and a portion (30) of these walls being removable to provide access to the interior of the chamber. Substantially all the internal surface of the chamber (1) is lined with cast silica-base plates (13, 14, 15, 16, 17) disposed side by side, having a coefficient of thermal expansion near zero. Used particularly in plate glass tempering furnaces.

Abstract: In a glass melting furnace of the type that has a basin wherein a bath of molten glass is heated by a blanket of flame that extends over the molten bath, performance and productivity are enhanced by installing oxygen injection lances through holes that are drilled through walls of the furnace at tuck stone levels just above the top surface of the molten bath of glass in the furnace basin. The lances are thin walled tubes that each carry an adjustable flange for preventing unwanted convection and radiation through furnace wall holes that receive the lances.

Abstract: A furnace for fining molten glass is provided in which glass flows in a substantially vertical direction prior to exiting the furnace. As it flows vertically, the glass is allowed to cool. This cooling, in turn, allows the glass to be removed from the furnace through a narrow passageway without producing excessive wear of the passageway. Preferably, vertical flow of the molten glass at the exit end of the furnace is produced across the furnace's full width. In this way, the molten glass does not stagnate within the furnace and undesirable scums on the top surface of the glass are avoided. In certain preferred embodiments, the vertical flow is achieved by means of a trough which has sloped sides and which connects with and extends downward from the bottom surface of the furnace.

Abstract: A conduit for conducting molten glass in a glass making operation comprising an elongate superstructure, an elongate carriage, a plurality of refractory blocks assembled on the carriage to form a channel for conducting molten glass, and a plurality of rollers for supporting the carriage in the superstructure and allowing the carriage to be slid out of the superstructure for servicing. The conduit further comprises clamping members extending along the sides of the conduit roof, and support members on the superstructure which can be operated transversely inwardly to cause the clamping member to engage and support the roof so that the carriage can be removed from the superstructure independently of the roof.

Abstract: A forehearth for transport of molten glass, characterized in that cooling surfaces of a material having a high heat conductivity, particularly a metallic material, are disposed in the roof of the forehearth. The metallic material may be an iron-chromium-aluminum alloy having fifteen to thirty percent by weight of chromium, three to twelve percent by weight of aluminum, and a balance of essentially iron.

Abstract: Disclosed are an energy saving method for melting glass in and a glass melting furnace for the practice of the method.A charge is melted in a melting section, clarified in a clarifying section adjoining the melting section, and then homogenized in an adjoining homogenizing section of increased bath depth and drawn therefrom. The charge is fed in at the beginning of the melting section and energy is supplied underneath the charging end through electrodes. The melting energy input is generated by combustion by fossil fuel burners in the clarifying section. The burner flue gases flow over the melting section countercurrently to the charge and are exhausted close to the charge end. The surface of the melting section is swept by a flow coming from the clarifying section countercurrently to the charge.

Abstract: Roof of a working tank or of a glass melting furnace having a basin containing molten glass and covered by the radiation roof of highly refractory firebrick material, in which the roof is constructed with horizontal supporting elements in the form of straight arches (3) bearing the load of the roof (1) and spanning the tank at intervals, and with horizontal slabs (4) covering the open intervals between the supporting elements (3) and laid crosswise between the supporting elements (3).

Abstract: Wate asbestos is converted into a glass by maintaining within an electrical glass melting furnace a body of molten glass at a temperature above the decomposition temperature of asbestos; supplying asbestos to the furnace by a conveyor discharging above the body of molten glass so that the asbestos falls onto the molten glass and becomes decomposed and melted into glass; and withdrawing molten glass from the furnace at a temperature of at least 1000.degree. C. The asbestos is advantageously mixed with cullet and a melt accelerator and fed into the furnace by means of a screw mixer/conveyor. The furnace is advantageously operated at a pressure less than atmospheric pressure.

Abstract: In a method of making glass or the like, wherein the batch materials are liquefied in a distinct zone from the refiner, the liquefied material is heated in an intermediate stage before being fed to the refiner. In preferred embodiments the intermediate stage comprises one or more channels extending from the side of the refiner.

Abstract: Foaming of molten glass or the like as it enters a vacuum refining vessel is enhanced by altering the incoming stream so as to increase its surface area and/or retarding the passage of the stream through the vacuum headspace so as to increase its exposure to the vacuum.

Abstract: A furnace for cooling molten glass, which comprises a cooling tank for slowly cooling the molten glass while the average temperature of the molten glass is within a certain range extending below and above the temperature at which the speed of absorbing bubbles is highest, and cooling it rapidly when the average temperature of the molten glass is outside said range.

Abstract: A glass melting furnace includes a furnace body including for storing molten glass, an upstanding tank including a bottom member lying flush with the bottom wall of the furnace body and a rear wall remote from the furnace body, the upstanding tank communicating with the furnace body, a feeder disposed upwardly of the rear wall of the upstanding tank and communicating with the upstanding tank, and a drainage mechanism disposed in a corner defined between the rear wall and bottom member of the upstanding tank for draining out heterogeneous molten glass. The upstanding tank has a width smaller than the width of the furnace body. The drainage mechanism comprises a through hole having an inlet opening into the upstanding tank and an outlet opening at a rear surface of the rear wall, the through hole being tapered from the inlet toward the outlet.

Abstract: The glass melting tank for supplying a flat glass forming process has a melting zone for melting solid batch material and a refining zone with reduced return flow of glass. The base of the refining zone comprises a fusion cast refractory material comprising alumina, silica and between 31% and 43% by weight of zirconia. The refractory is conditioned by oxidation at at least 1450.degree. C. for 24 hours.

Abstract: An alcove for conducting molten glass to a plurality of forehearths for delivery to glassware forming equipment, comprising a series of zones with a trough extending through the zones and a barrel vault roof over the trough in each zone, the vault bearing on blocks at the top of the sides of the trough carrying burners, the vault having keystones formed to provide side channels over side portions of the stream of molten glass in the trough and a central channel over the central portion of the stream.

Abstract: A channel made from refractory elements is fabricated without gaps or expansion joints between the refractory elements by supporting the channel upon a movable carriage to accommodate the lengthwise expansion of the channel as the temperature of the channel is increased from room temperature to its operating temperature.

Abstract: A glass delivery system is disclosed which includes a molybdenum delivery pipe surrounded by molten glass and inductively heated by a water cooled induction heating coil surrounding the molybdenum pipe and spaced apart therefrom by means of refractory material.

Abstract: Device for improving the heating of a channel (2) for distribution of glass (1), said device including a cylindrical duct (6) connected at its upstream end to means (7) for feeding a premixture of air and fuel gas and whose downstream end (8) opens inside a cylindrical bore (9) in a refractory block (10) inserted in a wall (11) of the channel, said cylindrical bore (9) extending by means of a coaxial cylindrical duct (12), of smaller diameter than that of said bore, the cylindrical channel (6) being surrounded by a sealing ring (13) which covers the face of the cylindrical bore (9) in which said channel (6) is inserted.

Abstract: A lid construction for a heating vessel. Discrete insulating members are supported by water cooled pipes above the vessel. The cooling pipes fit into grooves along the vertical side walls of the insulating members. Each member has a support independent from the supports for the other members so that an individual member can be removed within having to remove additional members.

Abstract: Device for continuous manufacture of fined glass in which the flow of molten material is transferred from a melting compartment (1) to a fining compartment (2) by a submerged throat (8), the fining compartment (2) comprising a chute (14) carrying the material, in an overall ascending current, and delivering it to the conditioning station (3), in a surface current, heating means (16-19) distributed in the chute (14) bringing the material to the usual debubbling temperature.This device is advantageously combined with a cupola type electric melting furnace, particularly for producing glasses with very volatile ingredients.

Abstract: A glass melting furnace including a melting tank heated from above by burners and comprising a melting section as well as a refining and homogenizing section provided with electrodes for the supply of electrical energy; a dam which separates the melting section from the refining and homogenizing section and the upper edge of which is disposed below the surface of the (glass) melt bath; and an outlet for the glass disposed in the bottom portion of the refining and homogenizing section; wherein the bottom of the refining and homogenizing section is in a position deeper than the bottom of the melting section, and the electrodes are arranged in one or more planes (levels) of the refining section, the glass melting furnace being configured such that on the side of the refining section there is provided adjacent to the dam a bottom portion which is disposed at a level substantially above the bottom of the homogenizing section.

Abstract: A forehearth for molten glass having at least one cooling zone which includes a trough and a roof over the trough. A pair of spaced projections extending downwardly from the roof to define a central channel over the molten glass and side channels over the respective side portions of the molten glass. The roof has an area of reduced thickness in the portion over the central channel. An enclosed upper cooling channel extends longitudinally over the area of reduced thickness and has an inlet and an outlet spaced from the inlet, and heating means are provided for each side portion of the forehearth.

Abstract: Temperature conditioning of molten glass flowing from a melter to a glassware-forming machine is described. In addition to the attempt at conditioning the molten glass in the forehearth in the usual manner, in accordance with this invention, distribution channels leading from the throat of the molten glass supply to the forehearth are provided with conditioning apparatus. Most particularly, the conditioning apparatus is such that the conditioning temperatures at the opposite sides of the distribution channel may be varied. For example, at one side the interior of the distribution channel may be being heated while the opposite side is being cooled. It is also possible to heat one side to a greater degree than the other while heating both sides. Most particular, the burner construction is such that the burners may be utilized either to heat the interior of the distribution channel or to cool the same.

Abstract: A forehearth for a glass furnace includes a roof formed of a plurality of roof blocks designed to provide below the roof blocks a central longitudinal channel and side channels on each side of the central channel. An electric heating element is positioned in a bore in the roof blocks substantially directly above the side channels to permit radiation of heat to the glass surface above the side channels. The temperature of the molten glass utilizing the construction can be effectively uniformly controlled across its cross-section.

Abstract: A temperature control system for a forehearth, said forehearth for thermally conditioning molten glass to be fed to a glassware forming machine, and being divided into a plurality of zones. Each of the forehearth zones is provided with devices for monitoring the temperature of molten glass within the zone, and apparatus for selectively heating the glass. A microprocessor-based time sharing system controls the temperature of the plurality of zones, using adaptive control loops. Each zone is assigned a time period for monitoring temperature and taking appropriate corrective action. Temperature adjustments may be made independently zone-by-zone, or in cooperation, and other physical parameters may be taken into account such as glass viscosity or combustion pressure. Certain time-sharing periods may be associated with monitoring and displaying functions only.

Abstract: A method of producing a glass product requiring minimum fining wherein finely pulverized glass batch material is heated very rapidly in suspension in a hot gas stream to at least about its melting temperature in a heating chamber and directing it through a nozzle to impact on an impact surface in a separation chamber where the glass batch material is separated from the hot gas stream by adhering to the impact surface.Upon impact, the particles and/or molten material form a continuously flowing layer which flows over a flow surface as a molten layer into a pool of molten glass product in a collection zone. The melt flow over the flow surface is controlled to effect the immigration of gas therein to and then leave the exposed surface of the melt flow and simultaneously effect at least substantial reaction of the glass batch material before it reaches the collection zone.

Abstract: A process and installation for heating a channel in which flows a mass of molten glass toward one or more forming machines. The channel includes a vault which carries at least one group of oxyfuel burners connected to a source of oxygen and to a source of fuel gas, these burners being so oriented as to produce curtains of flames directed towards the longitudinal marginal zones of the surface of the stream of molten glass.

Abstract: When primary fuel for combustion is combined with an amount of oxygen in excess of the stoichiometric amount required for complete combustion, in the ports of a glassmaking furnace, additional fuel is injected into the melting chamber to consume at least a portion of the excess oxygen and reduce at least a portion of NO.sub.x present in the melting chamber, to thereby reduce or suppress NO.sub.x emissions from the furnace.

Abstract: In order to conserve fuel in an apparatus for manufacturing glass, a continuous glass-melting tank furnace is provided with a melting compartment, a refining compartment, and a shadow arch between the compartments. The shadow arch is constituted by a cover which extends from a shadow wall at the downstream end of the melting compartment to an end wall at the upstream end of the refining compartment. The melting and refining compartments communicate via a passage beneath the shadow wall at the downstream end of the melting compartment, and a sill is positioned between this shadow wall and the refining compartment. The top of this sill is at least as high as the top of the passage.

Abstract: The present invention proposes a novel apparatus and method for the manufacture of glass fibers utilizing a bushing confining a body of molten glass over an orifice plate which may or may not have depending tips. Interposed in the glass body is a plate or other device for reducing the pressure of the molten glass body over the orifice plate to a pressure no greater than atmospheric pressure. The orifices are of relatively large diameter incapable of imposing a substantial pressure drop on molten glass flowing therethrough. Each tip contains a pool of molten glass at no greater than atmospheric pressure and, during fiber attenuation, a forming cone is drawn from the pool in each tip. The cones are located in the tips, each cone is smaller than the surrounding tip and each cone is stabilized on the interior tip wall by an annular glass portion integral with the cone. The process is dripless, since upon fiber interruption at any given tip, the molten glass pool remains in the tip.

Abstract: A forehearth for the conveyance of molten glass has at least one cooling zone which includes a trough and a roof over the trough. A pair of spaced projections extend downwardly from the roof to define in the space below the roof a central channel over the central portion of the stream of molten glass and side channels over respective side portions of the stream of glass. The roof has at least one area of reduced thickness in the portion over the central channel. An enclosed upper cooling channel extends longitudinally of the forehearth over the area of reduced thickness and has an inlet and an outlet spaced longitudinally from the inlet. Heating means are provided for applying heat to each side portion of the stream of glass.

Abstract: In a glass melting furnace, the beneficial effects of passing molten glass streams through the intensified heating at the surface of the "spring zone" are enhanced by the use of bubblers. In one aspect, the rate of bubbling is greater near a side wall of the furnace than in the center immediately upstream of the spring zone so as to direct side portions of the throughput stream into the spring zone. In another aspect of the invention, the rising currents of the spring zone are enhanced by bubbling a stream entering the spring zone at a first elevation and then bubbling the same stream portion at a higher elevation.

Abstract: A conditioning section of a forehearth is disclosed with sidewall electrodes for Joule effect heating of glass positioned and connected to confine the current and Joule effect heating separately to the side portions of the molten glass flow path therein. Separate circuits, controls, temperature sensors and temperature set point control means are provided for the sidewall electrodes on each side. Glass temperature across the flow path is controlled and can be adjusted by separately controlling the flow of Joule effect current along each side of the flow path through manual or automatic, thermally actuated, controls for each side.

Abstract: A centerline cooled forehearth for conditioning molten glass, wherein the sides of the flow channel of the forehearth are provided with external sheets of insulation. The channel is covered by a roof having vertical vents therethrough along the centerline with the usual burner blocks and burners spaced along the sides of the upper edge of the channel. Flue blocks are positioned immediately above the burner blocks, and their lower surfaces extend toward the centerline of the channel a greater extent than the burners, thereby serving as reflectors for the heat from the burners along the side walls of the channel.

Abstract: A glass making furnace wherein the glass constituents are fed from a hopper (10) into a melting chamber (15). Molten glass flows into the chamber (16) for passage through a homogenizer (25) for shear mixing of the glass and elimination of bubbles therefrom. A flow modulating valve (50) regulates the rate of flow of the molten glass to an extrusion nozzle (93).

Abstract: A transverse-burner recuperative furnace for glass making, which comprises burner blocks of which the inner aperture, of generally elongate rectangular shape, exhibits a first portion of constant cross-section extending from the rear face of the burner block, and a second portion progressively flaring upwards and downwards to the front face of the burner block, such second portion exhibiting an angle of flare .alpha. of not more than 15.degree., and the cumulated total length of these apertures representing at least 0.65 times the distance between the extreme burner blocks.

Abstract: Forehearths for use in glass production comprise a refractory trough (52) for molten glass with an insulating roof thereover, means for heating glass in the trough and means for blowing cooling air across the inside of the roof surface; the forehearth being constructed of at least two sections (A, B and C) which have different insulating characteristics from each other. Preferably the forehearth roof is made up of prefabricated block members of refractory material lying side by side and each of which member spans across the trough. Different insulation is provided over the prefabricated block members to provide different insulating characteristics within sections of the forehearth. The invention also provides prefabricated members for use in the construction of the forehearth according to the present invention.

Abstract: A conventional glass tank furnace used in the manufacture of glass is provided with a system for recovering heat which inevitably escapes from the furnace roof or crown above the melting and refining tanks of the furnace. A heat recovery plenum means is mounted on top of the furnace roof or crown, and an air blower supplies cool air to the plenum means through a first duct means. The cool air directed to the plenum means cools the furnace crown and in the case of a suspended flat arch crown, the supporting steel work. The cool air in the plenum means is heated by heat escaping from the furnace crown, and thereafter is directed through second duct means to a main combustion air blower where the heated air from the plenum means is mixed with primary combustion air and directed to the furnace and to the furnace burners. Control means are provided to maintain the air in the plenum means at positive pressure so as to prevent air in the furnace from escaping through the furnace crown.

Abstract: The present invention embraces apparatus for the production of mineral fibers. A bushing for the manufacture of mineral fibers, such as glass fibers, comprises an orificed bottom wall for the passage of streams of molten mineral material therethrough for attenuation into fibers, upwardly extending sidewalls and an orificed member, positioned above the bottom wall and extending between the sidewells, for passage of the molten mineral material therethrough to the bottom wall. The ratio of the poiseuille resistance to flow of the orificed member to the poiseuille resistance to flow of the bottom wall is in the range of from about 0.5 to about 1.0.

Abstract: A container between the output of a melting furnace wherein the molten mass is also refined, such as for glass, and the ducts to a plurality of forming machines comprising a larger first zone and a plurality of smaller second zones corresponding to each forming machine, in which container the molten mass is controlled in temperature above and below its liquid level as it flows through the first and second zone toward a forming machine so that the cross-sectional area of the molten mass at the outlet duct from each second zone has substantially a uniform temperature.

Abstract: An apparatus and method is disclosed for cooling a molten stream of glass flowing in a firebrick hearth from an entrance end to an exit end of a glass furnace forehearth, the method comprising the steps of: cooling the bottom of the hearth which cools the molten glass by forcing air through ducts in the hearth bottom insulation; cooling each side of the hearth which cools the molten glass by forcing air through ducts along the side of the hearth.

Abstract: In order to provide mixing between the freshly melted glass and that already in a glass melting vessel for spinning glass fibre, the vessel has a lateral extension having inlets for glass beads or pellets. These fall into a reception trough and the freshly molten glass passes over a first weir to a second reception trough normally just below the level of the glass in the vessel. The glass from the trough passes over a second weir. In order to prevent a direct access to the draw bar in the aperture a further trough and weir are provided. The draw bar may have nipples which are largely embedded in the plate so as to delay the onset of cooling as the glass passes through the nipples. This reduces the required temperature of entry to the nipples and enables the use of lower grade materials, such as alloy steel or nickel chromium alloy, for the plate and nipples.

Abstract: A glass delivery system is disclosed having a glass conducting pipe enclosed within a refractory structure. The refractory structure is spaced about the pipe and defines a closed space for receiving therein a quantity of the glass. Heat input devices are located in the closed space for supplying heat to the pipe. The refractory structure may include heat exchange passages for circulation of a first heat exchange fluid therethrough. Means may be included for introducing a second gaseous fluid within the closed space between the refractory structure and the pipe for removing heat given up by the glass and under certain conditions the first fluid may act as an inert atmosphere or purge gas for protecting certain components of the system from deleterious ambience. The first heat exchange fluid removes a relatively greater portion of the heat energy given up by the glass than the second fluid.

Abstract: There has been provided a delivery system for conditioning molten thermo-plastic material, wherein a first pipe member, having an inlet at one end adapted to receive the material and an outlet at an opposite end for delivering the material therefrom at a desired homogeneity is coupled at its inlet end to a furnace. An insulated shell structure, having at least one fluid inlet and outlet therein, is located concentrically about the first pipe member and defines a closed insulated space thereabout. The shell is adapted to receive heat exchange fluid for circulation from the inlet to the outlet in said closed space for removing heat from the thermo-plastic material flowing through the pipe member. Means is provided for shielding inside surfaces of space between the shell and the pipe member from deleterious ambient including a purge fluid which may act alone as the heat exchange fluid.

Abstract: A skimmer for use in a throat of a melting furnace. The skimmer comprises a plate having a plurality of passages therein with the passages being through the plate from a first side to a second side. Adjacent passages are in communication with each other to form a continuous passage through the plate. A first means for blocking the ends of the passages on the first side of the plate and a second means for blocking the ends of the passages on the second side of the plate are attached to the plate. A first port means is in communication with one end of the continuous passage for connecting with a cooling inlet located outside of the furnace, and a second port means is in communication with the other end of the continuous passage for connecting with a cooling outlet located outside of the furnace.