Abstract: A method of melting glass in a vortex reactor wherein first pulverized glass batch materials are entrained and preheated in a suspension preheater thereby creating a first gas-solids suspension. This first gas-solids suspension is thereafter mixed with a second gas-solids suspension comprised of additional glass batch material in a vortex reactor. The first gas-solids suspension and the second gas-solids suspension are introduced into the vortex reactor through at least one injector assembly. The stoichiometry and heat release in the vortex reactor are controlled by adjusting the oxidant/fuel ratio in the suspension preheater and the vortex reactor. The heated suspension particles are mixed and distributed to the walls of the vortex reactor by fluid mechanically induced centrifugal forces with glass forming reactions occurring along the vortex reactor walls. The formed glass is rapidly refined and homogenized along the vortex reactor walls in a thin layer under the influence of gas dynamic shear forces.

Abstract: A melting furnace is disclosed which heats by joule effect to supply molten material of uniform temperature at the floor of the melter. During formation of molten material, an essentially isothermal condition across a given horizontal plane of the body of molten material is established. Spaced apart opposed electrodes and controlled current flow establish these uniform temperatures and allow molten material to be formed directly from the melter without further processing.

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 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 rotary batch preheating kiln feeding batch materials to a batch liquefying vessel is separated from the liquefying vessel by a transition section including duct means to direct exhaust gas from the liquefying vessel to the interior of the rotary kiln at a location spaced from the discharge location of the kiln. The transition section also shields the rotary kiln from radiant heat from the liquefaction vessel.

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 forehearth supplied with molten glass from a tank furnace, with bottom passages overlying bushings for the extrusion of vitreous filaments, forms an elongate chamber whose sidewalls are penetrated by heating electrodes spaced apart in the longitudinal direction and arrayed in two relatively staggered tiers. The electrodes of the lower tier are more numerous in the vicinity of the bottom passages than between these passages. The heating effect of the electrodes can be supplemented by top burners disposed above the glass level.

Abstract: Removal of gas inclusions from a molten glass pool is enhanced by inserting a gas inclusion-permeable, refractory metallic or ceramic screen in the downstream flowing, upper portion of the pool, to diminish the glass flow rate adjacent the surface by viscous drag forces while permitting gas inclusions to rise through the screen to the surface of the molten glass pool to dissipate into the atmosphere therealong.

Abstract: The elongated burner is described which is capable of providing a ribbon of flame through which particulate material as small as 1 micron is uniformly dispersed and transported onto a rotating forming surface for formation of an ingot. In a preferred embodiment the burner is provided with a hollow interior defined by a cylindrical surface interrupted by a longitudinal groove in communication with a longitudinal discharge slot. The sides of the groove are sloped at an angle steeper than the angle of repose of the particulate material. In the preferred embodiment the exterior surface of the burner is likewise provided with a longitudinal groove in communication with the discharge slot and providing two surfaces angled toward each other and toward the path through which the discharged material travels.

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: Method and device for reducing NO.sub.x content in the waste gas generated in a glass melting furnace of side firing or end firing type equipped with a heat recovering device, comprising supplying hydrocarbons in a counter flow to that of the waste gas by combustion, or from the corners of the combustion chamber into the combustion chamber over the melt tank.

Abstract: A method and apparatus for melting low-cost raw materials such as blast furnace slag, basalt, feldspar or electrophos slag in the formation of high temperature mineral wool insulation. The low-cost mineral stock material is fed in particulate form continuously to a preheater in which it is elevated to a temperature range of between 1500.degree. F. and 2000.degree. F. by forcing hot combustion gases through a vertical column of the particulate stock material. Volatiles such as water and carbon dioxide are thus removed from the stock material. The preheated stock material is distributed to the top of an electric melting furnace which is essentially sealed from atmosphere. A substantially homogenous, low viscosity liquid glass melt is continuously discharged from the furnace.

Abstract: An improved glass melt tank (10) having a feeder (15) and a channel (14) which interconnects the tank and the feeder and in which is arranged a rotary, raisable and lowerable regulator (20, 21) which opens and closes the channel (14) so that the feeder (15) is supplied with molten glass from the tank (10) when a level sensing means (22) senses a lower level in the feeder, the supply of molten glass being caused to cease when an upper level is sensed. The regulator (20, 21) rotates continuously in order not to get stuck in setting glass and seals against a horizontal seat formed in the channel.

Abstract: A method of and apparatus for directing and regulating the flow of combustion air to opposite ends of the regenerators of a regenerative tank-type glass melting furnace so as to minimize localized overheating and more uniformly heat the checkerworks of the regenerators, thereby improving the operating efficiency and prolonging the useful life thereof. To accomplish these ends, a substantial portion of the combustion air supplied to the regenerators is delivered to their downstream ends while a lesser portion is supplied to their upstream ends by ducts which include valves for cycling and a damper for apportioning the amount of combustion air flowing to opposite ends of the regenerators.

Abstract: In an apparatus for conditioning a supply of molten thermoplastic material, preferably glass, a chamber in flow communication with the supply of glass is mounted for rotation about an axis. The chamber has a flow control surface having at least two regions, each uniquely oriented for influencing the flow of the molten glass therealong. In one region the glass experiences delayed flow to enable it to give up heat and in a region downstream of the first, the glass experiences accelerated flow to enable it to counteract changes in viscosity resulting from previous heat loss. The chamber is rotated so that a fresh supply of glass at an elevated temperature is deposited circumferentially on the flow control surface in order to moderate the influence of heat loss as the glass flows through the chamber.

Abstract: An apparatus for sealing between edge control machines and forming chamber sidewalls is disclosed. The invention comprises collar means mounted surrounding the barrel of the edge control machine, alignment means fastened to the edge control machine for maintaining the collar aligned with the barrel of the edge control machine, and a flexible sleeve between the collar and the forming chamber sidewall.

Abstract: The apparatus for manufacturing an ingot includes a rotatable housing with an inner surface defining an opening therethrough along the rotational axis of the housing. The housing is rotated about the rotational axis. The housing includes a layer of insulating material located between the inner and outer surfaces of the housing. Particulate material is deposited along the inner surface while the housing is rotating and the particulate material is heated above its melting temperature while the housing is rotating, the rotational movement holding the molten particulate material in place by centrifugal force on the inner surface for forming an ingot.

Abstract: Method and apparatus for forming glass fiber strand directly and continuously from raw batch glass-forming material, which includes means for continuously electrically melting raw batch, glass-forming materials, forehearth and fiber forming means for continuously receiving said melted glass, means for continuously attenuating said glass from said fiber forming means in the form of a multiplicity of fiberglass filaments, and means for converging and winding said filaments in the form of a fiberglass strand.

Abstract: A method of inclusion melting of glass with radioactive components and a furnace for carrying out the method. Radioactive components are fed in the form of an aqueous suspension or of a slurry into a furnace from above in combination with a mixture for the melt forming of glass, or the mixture for the melt forming being formed from the radioactive components. The molten mass of glass and radioactive components is heated by passing electrical current directly therethrough, wherein the mass flow takes place solely vertically from top to bottom.

Abstract: Substantially gas free raw materials are melted to form molten glass by urging a bed of particulate materials toward a resistance heating member. The solid materials are urged into close proximity with the resistance heater and, at most, a thin film of molten glass is maintained on the heater plate. The heater plate contains one or more passages through which the molten glass flows into a heated reservoir in which the glass achieves the requisite homogeneity.

Abstract: A method and apparatus are disclosed for heating molten glass in a forehearth of a glass furnace connected to a plurality of feeder conduits. An electrode is positioned at the inlet of the forehearth and another electrode is positioned at the inlet of at least one of the feeder conduits. As a stream of molten glass is directed from the inlet of the forehearth to the inlet of the feeder conduit, the electrodes are energized to produce an electric current flow between the electrodes and through the molten glass stream to heat the glass.

Abstract: The improvement in an apparatus for refining glass being fed along a channel wherein the molten glass is foamed throughout its thickness, the improvement involving an increase in the width of the channel at the location of foaming. Also, the channel is provided with submerged electrodes disposed on opposite sides of the channel adjacent the bottom for heating the molten mass to produce the foaming.

Abstract: In the manufacture of flat glass by feeding molten glass from the outlet end of a glass melting furnace to an exit channel which conducts the molten glass to forming apparatus, the furnace sole is inclined upwardly toward the exit channel in the vicinity of the furnace outlet end.

Abstract: A feeder conduit is disclosed for conveying molten glass from a forehearth of a glass furnace to a glass forming machine. The feeder conduit includes an elongated conduit which receives molten glass from the forehearth and delivers the molten glass to an inlet of a bowl-shaped container. The container has an orifice in its bottom for withdrawing the molten glass therefrom and a vertical cylinder disposed within the container and above the orifice. The cylinder and side wall of the container opposite the inlet of the container define a semi-annular channel therebetween and a first electrode is inserted in the molten glass upstream of said cylinder and a second electrode is inserted in the molten glass within the semi-annular channel. The first and second electrodes are offset from the centerline of the feeder conduit. As the molten glass flows through the inlet in the container, around the cylinder and through the semi-annular channel, an electric current passes between the electrodes to heat the molten glass.

Abstract: A delivery system is disclosed for pumping and pressurizing viscous fluid materials, such as molten glass. The pump comprises a rotating rotor which is located in a channel of the viscous fluid, such as in the forehearth of a glass melting furnace. In a glassmaking operation, the rotor uses the viscous drag of the molten glass against it to pump the molten glass from an open channel into a closed and pressurized channel where the pressurized molten glass may be, for example, extruded into glass filaments. The pumping system described also finds utility in pumping other viscous materials such as resins in fluid form.

Abstract: In the refining zone of a glass melting tank the molten glass is supported on a heat conducting base, such as molten tin, heat is removed from the glass through the base and the depth of glass, length of refining zone and temperature difference between the inlet and outlet of the zone are controlled so that the ratio of return flow to forward flow through the zone is between 1/6th and 1/2.

Abstract: A forehearth for a glass furnace includes a roof having a plurality of longitudinal ridges depending therefrom. These define a central longitudinal channel lengthwise of which a current of cooling air flows between inlet and outlet ports to cool the central, hottest portion of the stream of glass in the forehearth, and side channels which serve to reheat the side portions of the stream of glass. A plurality of longitudinally spaced electrodes are suspended from the portions of the roof over the side channels and are inserted in the molten glass to directly heat the side portions. Advantageously the electrodes in one side channel are energized in pairs independently of the electrodes in the other side channel. Preferably the electrode assemblies are mounted in apertures extending through the roof. Molybdenum electrodes with air cooled tubular holders encircled by refractory tubes and isolated from ambient air are described.

Abstract: Glass is melted in a furnace having a melting zone and one or more processing zones adjacent to the melting zone. A volume of molten glass is caused to flow from the melting zone to the processing zone in a volume which exceeds the volume of glass withdrawn from the processing zone. The excess volume of glass is returned to the melting zone 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 is provided between the processing tank and the melting section and additional means are provided to establish a circulating flow of molten glass via the recirculating passage.

Abstract: The apparatus is a rotatable resistance heating furnace including a rotatable cylindrical body portion having an interior space in the form of a truncated cone. The base of the truncated cone forms a discharge opening for rapid discharge of the amorphous silica. The furnace is provided with a resistance heating element which extends into the furnace interior through a top opening. In one embodiment a slidable filling tube is provided for charging the furnace during rotation thereof. The process utilizes the above-described apparatus and involves heating the crystalline silica to a temperature sufficient to convert it to the amorphous state, evacuating the furnace during the conversion to draw off by-product gases, and rotating the furnace to a speed sufficient to bring about a separation between the silica charge and the resistance heating element.

Abstract: A glass melting furnace in which glass can be heated by sources below its upper surface, as electrically by Joule effect, and by means above its upper surface, as by fossil fuel firing or by heat reflectors. A cold top melting mode is employed in the charging region of the furnace while the glass discharge region maintains an exposed molten, upper surface on the glass. In a disclosed embodiment a high crown over the charging region enables cold top melting and refining to be accomplished by Joule effect while flues and burner ports in that region are closed. A low crown, which may be adjustable in its height above the glass line, is provided over the discharge region to increase heating at the exposed, molten upper surface of the glass by reflection. Heating in the discharge region can be augmented by above surface heaters distributed across the crown. A flue in the discharge region carries gases from that region.

Abstract: A feeder for delivering streams of molten mineral material for attenuation into filaments having an electrically conductive bottom wall with orifices formed therein. The molten material in the feeder passes through the orifices and is delivered as streams for attenuation into fibers. Extending from the bottom wall, in a direction generally normal to the plane of the bottom wall, are electrically conductive side and end walls. Positioned within the feeder generally parallel to the plane of the bottom wall is a molten material conditioning means. On the exterior surface of each of the end walls there is a terminal for conducting electrical energy to the feeder to heat the walls and molten material conditioning means of the feeder and thereby condition the molten material in the feeder. Each of the terminals has an inner portion attached to the end walls at the location of the molten material conditioning means. The inner member is positioned so that it is generally parallel to the plane of the bottom wall.

Abstract: A glass melting furnace having a melting section and an adjacent refining section. The two sections are interconnected by a step or barrier which reduces the cross-sectional area of the furnace. The refining section has at least one plane of a plurality of electrodes immersed in the molten glass mass thru which energy is supplied to the molten glass mass. A refining zone is positioned below the region containing the electrodes from which refined glass is discharged thru an outlet therein.

Abstract: A horizontal glassmaking furnace adapted for melting glass batch materials by the application of heat to them from overhead flames within the furnace is provided with submerged electric heating electrodes in a region adjacent to where glass batch materials are charged to the furnace and, while overhead flames are reduced or eliminated above the glass batch materials in the vicinity of the electrodes, the glass batch materials are melted from below by action of the electrodes; overhead flames are maintained above exposed molten glass where the glass batch materials have already melted. Discharge of particulate batch materials from the furnace by action of overhead flames is substantially reduced while the thermal efficiency of the furnace is enhanced.

Abstract: A vertically elongated glassmaking furnace is provided with two groups of electrodes: one group is positioned in the upper portion of the furnace and is operated to melt glass batch and to establish an upward flow of hot glass along the center of the furnace; a second group is positioned in the lower portion of the furnace and operated to slow the downward flow of molten glass through the furnace, particularly near the walls of the furnace so that all the molten glass in the lower portion of the furnace flows uniformly downwardly to discharge at a rate sufficiently slow to insure the upward escape of seeds or bubbles from the discharged glass.

Abstract: A vertically elongated glassmaking furnace is provided with two groups of electrodes: one group comprises crossed pairs of electrodes positioned in the upper portion of the furnace and is operated to melt glass batch and to establish an upward flow of hot glass along the center of the furnace; a second group is positioned in the lower portion of the furnace and operated to slow the downward flow of molten glass through the furnace, particularly near the walls of the furnace so that all the molten glass in the lower portion of the furnace flows uniformly downwardly to discharge at a rate sufficiently slow to insure the upward escape of seeds or bubbles from the discharged glass. The crossed. pairs of electrodes are energized in such a way as to provide intersecting lines of current flow with the loci of intersection in the vicinity of the central vertical axis of the furnace.

Abstract: The proposed glass melting apparatus comprises a cooled cylindrical chamber having an upper portion and a lower portion connected by an intermediate member, the lower portion of the chamber having a greater diameter than the upper portion and housing a cooled hollow body, the bottom of said body facing upwards. Said body is arranged above the level of the molten glass and is intended to raise the hydrodynamic stability of the mass of molten glass.

Abstract: In the production of glass fibers by the use of a multi-tipped bushing arranged beneath an opening in the floor of a fore-hearth along which the molten glass flows, an apertured cover plate is disposed across the opening at or near its bottom and carries an upwardly extending duct connecting the aperture in the cover plate with a position in the fore-hearth above the floor and below the normal surface level of the glass, so that molten glass is supplied to the bushing from this position, where the glass is uninfluenced by cooling effects, and on its way thence to the bushing the glass can only contact the surface of the duct which is kept hot by the molten glass in the floor opening outside the duct. The risk of divitrified glass reaching the bushing and causing breakages is thereby much reduced.

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 glass melting furnace, a pair of substantially horizontally and longitudinally extending barrier rods are provided just beneath the surface of the molten glass closely adjacent to the sides of the floating batch blanket so as to maintain the batch blanket spaced from the sidewalls of the furnace.

Abstract: A method of removing undesirable gaseous inclusions also known as seeds and bubbles, from seed containing unrefined molten glass by introducing this unrefined molten glass into a rapidly rotating contained glass mass, subjecting the unrefined molten glass mass to centrifugal forces substantially greater than gravity and developing static pressure differences in the glass mass resulting in pressure gradients in the molten glass and causing the gaseous inclusions to migrate to areas of lower static pressure and to the atmosphere from the molten glass. The introduced stream of unrefined molten glass is directed by a plurality of diverters into many paths, downwardly and outwardly toward the chamber wall, to provide a favorable force on the entrapped inclusions to increase both number and sizes of inclusions removed from the molten glass, and delivering refined molten glass from the contained glass mass, having reduced numbers and sizes of gaseous inclusions.

Abstract: The specification describes a method for producing a glass flow of high homogeneity in a tank furnace in which a selected layer of refined glass underneath the surface layers and above the bottom layers is drawn off at a point spaced from the end wall of the tank towards which the glass flows and is supplied to the processing station. The surface layers and the glass layers lying underneath the selected layer are returned into the refining section of the tank at a point upstream from the point of removal of the selected layer. Recirculation of the surface layer is encouraged by proper location of surface heating means and/or cooling means in the refining section in the tank.