Abstract: Heating apparatuses and methods for glass tubing manufacturing are disclosed. A heating apparatus for glass tubing manufacturing includes a bowl configured to receive molten glass and a plurality of heating elements thermally coupled to the bowl. The bowl has a bowl height and includes a tub portion configured to hold the molten glass, a bowl well extending beneath the tub portion, and an orifice at a distal end of the bowl well. The plurality of heating elements include a first heating element disposed at a first vertical location along the bowl height, a second heating element disposed at a second vertical location along the bowl height, wherein the first vertical location is vertically spaced apart from the second vertical location.

Abstract: A melter apparatus includes a floor, a ceiling, and a wall connecting the floor and ceiling at a perimeter of the floor and ceiling, a melting zone being defined by the floor, ceiling and wall, the melting zone having a feed inlet and a molten glass outlet positioned at opposing ends of the melting zone. Melter apparatus include an exit end having a melter exit structure for discharging turbulent molten glass formed by one or more submerged combustion burners, the melter exit structure fluidly and mechanically connecting the melter vessel to a molten glass conditioning channel. The melter exit structure includes a fluid-cooled transition channel configured to form a frozen glass layer or highly viscous glass layer, or combination thereof, on inner surfaces of the fluid-cooled transition channel and thus protect the melter exit structure from mechanical energy imparted from the melter vessel to the melter exit structure.

Abstract: A melter apparatus includes a floor, a ceiling, and a wall connecting the floor and ceiling at a perimeter of the floor and ceiling, a melting zone being defined by the floor, ceiling and wall, the melting zone having a feed inlet and a molten glass outlet positioned at opposing ends of the melting zone. Melter apparatus include an exit end having a melter exit structure for discharging turbulent molten glass formed by one or more submerged combustion burners, the melter exit structure fluidly and mechanically connecting the melter vessel to a molten glass conditioning channel. The melter exit structure includes a fluid-cooled transition channel configured to form a frozen glass layer or highly viscous glass layer, or combination thereof, on inner surfaces of the fluid-cooled transition channel and thus protect the melter exit structure from mechanical energy imparted from the melter vessel to the melter exit structure.

Abstract: A process and apparatus for removing molten glass from flow channels for the transport of production glass that are installed between a melting furnace and an extraction point for the production glass. The flow channel has a glass-resistant inner lining. A drainage unit for bottom glass is installed upstream of the extraction point for the production glass. In order to keep electrodes away from the molten glass, but still maintain a local and temporal influence on the temperature profile within the cross section, the inner lining, at least in the area of the drainage unit, is formed of a fusion cast electrically conductive material which has a drainage opening for the bottom glass with a drainage slit above it. At least two electrodes are installed on opposite sides of the flow channel and the drainage unit for the bottom glass.

Abstract: The present invention significantly modifies “The Overflow Process”. It includes a method and apparatus for measuring glass flow rate and maintaining a constant glass flow rate. It also embodies design features and methods that support and stress the forming apparatus in a manner such that the deformation that results from thermal creep is corrected, thus minimizing the effect of the thermal creep on the thickness variation of the glass sheet. The present invention also embodies design features that change the process from a single step (combined flow distribution and cooling) to a two step process; step one being flow distribution and step two being cooling.

Abstract: A method of forming a glass melt including heating a glass feed material in a first melting furnace to form a glass melt, flowing the glass melt into a second melting furnace through a refractory metal connecting tube, and further heating the glass melt in the second melting furnace. The refractory metal connecting tube is heated to prevent the molten glass from excessive cooling, and to ensure that the glass melt entering the second melting furnace is equal to or greater than the temperature of the glass melt in the second melting furnace. An apparatus for performing the method is also disclosed.

Abstract: A cooled discharge unit of an apparatuses for processing homogeneous/heterogeneous radioactive wastes with ion-exchange resins. The cooled discharge unit has a discharge pipe, a cooling jacket having a U-shaped form in cross section, a collector for feeding a coolant into the jacket, a discharge gate having a pipe, on one end of which is a cone-shaped tip and on the other end of which is a lid with an aperture.

Abstract: The invention relates to a skull pot (1) for melting, crystallizing or refining inorganic substances. Said pot comprises a pot wall (1.1), a pot bottom (1.2), an induction coil (2) which surrounds the pot wall (1.1) and by means of which high-frequency energy can be coupled into the content of the pot. The pot wall (1.1) is formed by a ring of metal pipes which can be connected to a cooling medium. Slits are embodied between adjacent metal pipes. The bottom (1.2) is provided with a discharge for the melt (3). A sleeve (4) is allocated to the discharge. The admission end (4.1) of the sleeve (4) protrudes far into the inner chamber of the skull pot (1) in such a way that, during use, the melt (3) can be withdrawn through the crystallized bottom layer (3.3) in a controlled manner without the danger of impairing quality.

Abstract: Apparatus for forming a cased glass stream having an inner core glass surrounded by an outer casing glass that includes a spout for delivering core glass from a first source through a first orifice. 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 a gap between the first and second orifices. A tube delivers casing glass from the outlet opening of a casing glass spout to the annular chamber in such a way that glass flows by gravity through the orifices from the first and second sources to form the cased glass stream. A hollow tube within the casing glass spout is positioned with respect to the spout outlet opening for metering flow of casing glass through the outlet opening and delivery tube to the annular chamber surrounding the orifices.

Abstract: Method of heating glass contacting surfaces, comprising heating the glass contacting surfaces to a predetermined operating temperature by combustion of a hydrocarbon fuel gas mixture which includes 90% by volume of MAPP gas and 10 percent by volume of propane. Another method blends the MAPP with air and/or natural gas. A novel hydrocarbon fuel gas mixture which includes 90% by volume of MAPP gas and 10% by volume of propane.

Abstract: The invention relates to a method for producing thin glass panes, especially glass panes with a thickness of below 1 mm, by drawing a thin glass strand vertically downwards. According to the inventive method, a glass melt is fed from a melting bath via a feed to the glass drawing tank that comprises a nozzle system with at least one slotted nozzle. The length and the diameter of the feed as well as the viscosity of the glass melt present in the feed determine the overall throughput. The throughput per length unit in the transverse direction to the glass strand (so-called line throughput) is adjusted via the geometry of the nozzle system and via the viscosity of the glass melt present in the nozzle system. These parameters are adjusted in such a manner that the glass, when leaving the nozzle system, does not wet the bottom of the slotted nozzle in the range of the tearoff edge.

Abstract: Apparatus for forming a cased glass stream having an inner core glass surrounded by an outer casing glass that includes a spout for delivering core glass from a first source through a first orifice. 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 a gap between the first and second orifices. A tube delivers casing glass from the outlet opening of a casing glass spout to the annular chamber in such a way that glass flows by gravity through the orifices from the first and second sources to form the cased glass stream. A hollow tube within the casing glass spout is positioned with respect to the spout outlet opening for metering flow of casing glass through the outlet opening and delivery tube to the annular chamber surrounding the orifices.

Abstract: High purity direct deposit vitrified silicon oxyfluoride glass suitable for use as a photomask substrates for photolithography applications in the VUV wavelength region below 190 nm is disclosed. The inventive direct deposit vitrified silicon oxyfluoride glass is transmissive at wavelengths around 157 nm, making it particularly useful as a photomask substrate at the 157 nm wavelength region. The inventive photomask substrate is a dry direct deposit vitrified silicon oxyfluoride glass which exhibits very high transmittance in the vacuum ultraviolet (VUV) wavelength region while maintaining the excellent thermal and physical properties generally associated with high purity fused silica. In addition to containing fluorine and having little or no OH content, the inventive direct deposit vitrified silicon oxyfluoride glass suitable for use as a photomask substrate at 157 nm is also characterized by having less than 1×1017 molecules/cm3 of molecular hydrogen and low chlorine levels.

Abstract: Apparatus to amalgamate a paste of vitreous material in the molten state with an additive material in the form of granules, scales, slivers or filaments, made of metal, of other types of glass or other material in order to obtain a vitreous compound. The apparatus comprises containing means (11) to contain the paste of vitreous material, mixing means (15) to convey the vitreous compound downwards, in its molten state, towards rolling means (12) to produce manufactured articles. The mixing means (15) comprise at least a first pair of mixing cylinders (19a, 19b) having the respective axes of rotation (20a, 20b) arranged substantially horizontal, parallel to each other and substantially parallel, or slightly inclined, with respect to the direction in which a rolling force is applied by said rolling means (12).

Abstract: A forehearth (20) for cooling glass from a melting furnace as it flows to a feeder bowl (28) from which it is discharged to a forming machine. The forehearth is in the form of an elongate, horizontally extending insulated trough (26) with a roof formed by a longitudinally extending series of roof block elements (30), each of which is of one-piece construction and extends completely across the width of the insulated trough. The downwardly facing surface of each roof block element is contoured to incorporate concave portions (30a, 30b) near the edges of the forehearth, a concave portion (30c) above the center of the forehearth and convex portions (30d, 30e) separating the center concave portion from the side concave portions to substantially impede heat transfer between the side concave portions and the center concave portion.

Abstract: The invention relates to the electric melting technique, in which the melting energy is dissipated in the bath of melted glass as a result of the Joule effect by means of electrodes which dip through the surface of the bath. According to the invention, the electrodes dip into a bath of melted glass which has a height h below 800 mm and a surface S such that the ratio h/S is lower than 0.5 m/m.sup.2. According to another aspect, the exchange surface between the electrodes and the bath is above 0.075 m.sup.2 /m.sup.3 of glass.The invention is used in the manufacture of glass-based products, such as insulating materials based on glass fiber.

Abstract: A method and apparatus for delivering a glass stream comprising a first inner layer and a second outer layer, comprising a generally vertical orifice, and delivering glass from a second source such that the glass from said second source provides an outer layer about the glass from the first source as it flows through said orifice. A resistance heated tube assembly is made of platinum or material having similar resistance heating properties and extends from a glass source to an orifice through which the glass flows from a glass source for the inner layer. The tube assembly includes a tube portion having an inlet end that communicates with the source for the outer layer and an outlet end that communicates with the source. The tube portion has an axis positioned at any angle ranging between the horizontal and vertical but preferably has an axis which is more vertical than horizontal. Flanges are secured to the ends of said tube portion, and the flanges are connected to an electric power supply.

Abstract: An insulating flow block having a plurality of bores extending therethrough to permit the flow of molten fiberizable material through the block, a bushing assembly having a bushing block with one or more bores extending through a peripheral region thereof to divert a portion of a supply of molten fiberizable material from a central region of the bushing block to the peripheral region of the bushing block, and a bushing positioned in general registry with the bore of the peripheral region of the bushing block to facilitate the flow of molten fiberizable material to a peripheral region of the bushing is disclosed.

Abstract: An apparatus for delivering a glass stream including a first inner layer and a second outer layer, including a generally vertical orifice, and delivering glass from a second source such that the glass from said second source provides an outer layer about the glass from the first source as it flows through the orifice. A resistance heated tube assembly is made of platinum or material having similar resistance heating properties and extends from a glass source to an orifice through which the glass flows from a glass source for the inner layer. The tube assembly includes a tube portion having an inlet end that communicates with the source for the outer layer and an outlet end that communicates with the source. The tube portion has an axis positioned at any angle ranging between the horizontal and vertical but preferably has an axis which is more vertical than horizontal. Flanges are secured to the ends of the tube portion, and the flanges are connected to an electric power supply.

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: Apparatus for forming a cased glass stream having an inner core glass surrounded by an outer casing glass includes a spout for receiving core glass from a first source and delivering such glass through a first orifice. 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 tube delivers casing glass from a second source 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. The core glass delivery spout includes a reservoir for receiving and holding the core glass, and having at least one lower opening of a first diameter. An orifice ring is positioned beneath the reservoir, and has at least one opening of second diameter less than the first diameter aligned with the first opening and forming the first orifice.

Abstract: A bushing assembly is provided which is adapted to be positioned beneath a forehearth (30) to receive a stream of molten glass flowing from the forehearth (30). The assembly comprises a glass receiving block (76), a bushing (50) and at least one cooling element (82). The receiving block (76) is positioned adjacent to the forehearth (30) to receive the stream of molten glass flowing from the forehearth (30). The receiving block (76) has an orifice (72) through which the molten glass passes. The bushing (50) receives the stream of molten glass from the glass receiving block and supplies a plurality streams of molten glass to be drawn into continuous glass fibers. The at least one cooling element (82) extends into the stream of molten glass and transfers energy in the form of heat away from the molten glass.

Abstract: A device for shaping rods, in particular, of a glassy material, by casting said material in a molten state in a mold, characterized by the fact that said mold comprises a) a cylindrical internal wall of a porous material and b) a means to inject a gas in this wall and cause it to come out of the wall on the side facing the glassy material accumulated in the mold, so as to constitute an interstitial flow of a film of gas that separates the glassy material from the inside wall of the mold.

Abstract: A tube assembly for use in a spout bowl assembly including a bowl for receiving molten glass having a central orifice closed by an orifice plate having one or more openings and a corresponding plurality of vertically reciprocating plungers associated with the orifice openings, the tube assembly comprising a tube mounted for rotation about a vertical axis. The tube includes a plurality of vent holes arranged horizontally around the tube, and a heat baffle including a cylindrical side wall and a bottom wall for closing the cylindrical side wall, an opening in the bottom wall for accommodating one or more reciprocating plungers. The bottom wall includes a downwardly projecting conical surface extending substantially around the bottom wall, and the heat baffle mounted so that the conical surface is horizontally adjacent the tube vent holes.

Abstract: An apparatus for continuously forming a glass-ceramic which melts raw materials and forms melted glass to a predetermined shape without cutting the melted glass and thereafter continuously crystallizes the formed glass to the glass-ceramic is provided.

Abstract: A feeder trough for transferring molten glass from a glass furnace to an object-forming station, the feeder trough comprising a channel at one of its ends to the furnace and at its other end to a bowl having at least one feeder orifice a sill which has, on its downstream face, a substantially vertical wall, occupies the entire width of the channel and has a thickness of approximately 4 to 10 cm and a height such that it allows a stream of glass approximately 8 to 10 cm thick to pass over it; and a heatable bottom drain provided upstream of the sill and practically adjoining the latter.

Abstract: In a method of and an apparatus for melting glass having high reducing activity when melted, a glass raw material charged into a melting vessel having a wall formed of platinum or alloy thereof is heated and melted. Oxygen gas is supplied to an outer surface of the melting vessel to raise oxygen partial pressure within an atmosphere surrounding the melting vessel. The oxygen gas is caused to penetrate through the wall of the melting vessel, thereby supplying the penentrated oxygen to a layer of the molten glass which is in contact with an inner surface of the wall of the melting vessel, so that the layer of the molten glass is formed into a protective glass layer rich in oxygen, for protecting the wall of the melting vessel from the molten glass.

Abstract: A method and means for producing mineral wool from coal slag is described wherein molten coal slag is transferred from a coal slag tank in an electrical generation plant. The molten coal slag is transferred to a fiberization apparatus and is heated during the transfer process to maintain the coal slag in a molten state. In the fiberization apparatus, the molten coal slag is subjected to compressed air streams which creates mineral wool fibers which are collected in a collection apparatus.

Abstract: A bottom tap of a glass melting furnace comprises a tap brick with a tap hole in which glass is frozen when the tap is not in operation and seals the tap. A tap gate of refractory and non-oxidizing metal is urged against the tap brick underneath the tap hole which is connected as an electrode to a counter-electrode situated in a glass bath. A tap chamber is situated underneath the tap gate, and a removable insulation is provided for the tap chamber.

Abstract: A straight line shear mechanism has rack driven shears which are operated by a pneumatic cylinder. The shear slides provide a barrier to infrared energy directed at the pneumatic cylinder. To cool the cylinder, a perforated cooling tube is connected to ambient air when the mechanism is operating and is connected to water when the mechanism is not operating.

Abstract: A mold cooling arrangement includes a plurality of closed bores vertically disposed in the mold between the molding surface and the mold exterior. A manifold positioned vertically above the mold communicates with the interior of each bore and a condenser is disposed vertically above and communicates with the manifold. The bores and manifold are at least partially filled with a liquid such as distilled water which partially evaporized during operation of the mold and the vapor rinse to the condenser is converted back to liquid and return by gravity to the manifold and mold bores.

Abstract: Improvements in devices for metering the flow of molten material such as glass include a catenary support structure, internal passageways in the bulbous valve body for directing molten material to the downstream side of the support arm or arms, and electrical isolation of the valve components from each other to recude electrolytic corrosion. An advantage of the invention is that use of precious metals such as platinum is avoided.

Abstract: According to the invention, ventilating air blown around and/or in the walls of a mould is cooled so as to maintain substantially constant, at least during predetermined periods of time, the temperature of the air around and/or in the walls of the mould, irrespective of the ambient 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: A spout assembly for use in feeding gobs of molten glass to a glassware forming machine which includes a spout bowl, a plurality of burner blocks on top of the spout bowl and a plurality of cover blocks on top of the burner blocks. Adjacent ends of both the root blocks and burner blocks form a junction which has a jog therein to provide a baffle effect to prevent heat loss. The cover blocks also have a projection extending downward therefrom that taper downward and inwardly toward the axis of the spout bowl.

Abstract: An apparatus for preventing the solidification and accumulation of material from the tapping jet in and on the tapping spout in the manufacture of mineral wool includes at least one oxy-fuel burner at the discharge section of the tapping spout to the spinning machine. The burner (13) is disposed at such a distance and directed such that the discharge section of the tapping spout and the first portion of the tapping jet departing from the spout are heated by the burner flame and the impulse of the burner flame is of such a size that the configuration and position of the jet will remain unaffected.

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 flat plate bushing is described which eliminates extensive precious metal use in drain and/or production bushings. The bushing utilizes a novel arrangement of insulation members and support plates that allow the bushing to be electrically heated and a novel method of connecting the bushing to a power source using the bushing face plate as the connection point is also shown.

Abstract: A flat plate bushing is described which eliminates extensive precious metal use in drain and/or production bushings. The bushing utilizes a novel arrangement of insulation members and support plates that allow the bushing to be electrically heated and a novel method of connecting the bushing to a power source using the bushing face plate as the connection point is also shown.

Abstract: When multiple gob feeders are used in which an enlarged tube is necessary to accommodate a row of plungers, a substantial surface area of glass is exposed to radiation or convection cooling and, to avoid excessive heat loss, a pair of heat baffles are used which extend downward into the tube at either side of the row of plungers. The baffles have lower portions which occupy a significant part of the space between the plungers and tube, and act as barriers against the movement of heat up through the space therebetween. The pair of baffles are so configured that they may be raised from the tube without requiring the removal of the plungers. Further, the baffles are supported in the tube by the tube support and therefore will be raised or lowered with the tube when it is adjusted.

Abstract: A method for tapping a furnace contains a tappable melt of silicon dioxide to be reduced to silicon with carbon, which comprises providing a graphite tap pipe on the furnace, and electrically heating the tap pipe to cause liquid silicon to flow out of the pipe, and a device for carrying out the method.

Abstract: A freeze valve for a molten glass discharging nozzle is disposed at the bottom of a glass melting furnace. The freeze valve has at least two sets of temperature control units provided around the nozzle and arranged in series in the longitudinal direction of the nozzle, and an ejector for ejecting a high-pressure gas disposed at the lower end of the nozzle and adapted to eject the high-pressure gas toward the axis of the nozzle. Each of the temperature control units includes heating and cooling means so as to heat and cool independently both the upper and lower portions of the nozzle.

Abstract: A method and apparatus for electrically melting solidified glass in difficult to reach regions of a glass melting furnace not readily accessible with fossil fuel heating means and, more particularly, to an electrode arrangement for electrically heating solidified glass in difficult to melt regions such as a submerged outlet throat between a furnace melter section and the riser through which the glass is supplied in production.

Abstract: A method and apparatus for periodically discharging batches of a glass melt from a ceramic glass melting furnace in which localized heating energy limitable in time is supplied to the glass melt by means of electrodes in the furnace, the furnace being provided at its bottom with an induction heatable outlet member of ceramic material presenting a vertically oriented outlet passage for discharge of such batches, the furnace being operated to cause the outlet passage to be closed by a plug of the glass when no discharge is to take place, in which such plug is melted for discharging a batch of the glass melt via the outlet passage by preheating the outlet member and the glass plug by induction heating up to a preheating temperature which is below the melting temperature of the glass and above which the rate of increase of the electrical conductivity of the glass plug as a function of increasing temperature is greater than that of the ceramic material of the outlet member, and then further heating the plug, while

Abstract: A fused silica glass tube (26) is extruded from a melt (21) in a chamber (11) pressurized with an inert gas. A shield is placed in close, spaced, relation to the melt (21) surface during the gas pressure extrusion process to substantially eliminate losses from the melt due to vaporization.

Abstract: A glass delivery system is disclosed having a central glass conducting pipe enclosed within a heat exchange structure. Heat shields reflect energy back to the pipe for reducing heat losses from the pipe and heaters are located about the pipe to add heat energy as required. Heaters which may be immersed in surrounding glass, are provided externally of the pipe at connections into and out of the pipe, and a bellows arrangement for accommodating expansion due to thermal cycling is provided in at least one of such connections. In a preferred embodiment, oxidizable refractory metals are used which may be protected from contamination by providing inert or reducing purging atmospheres or vacuum. Heat losses may also be regulated by atmospheric control of the purging atmosphere as well as control of a working fluid for the heat exchange structure. Means may be provided for shielding or insulating refractory components from intense radiation.

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. Flow control means is provided for regulating flow through the pipe. Means is further provided for isolating the flow control device from glass in the closed space to thereby avoid a bypass of said flow control device. A method for operating a glass delivery system is also disclosed.

Abstract: A method and apparatus for fiberizing molten mineral material of the type in which molten mineral material is supplied to a spinner and centrifuged by the spinner into mineral fibers, is characterized by fiberizing the molten mineral material at a temperature below the liquidus temperature of the molten mineral material.

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: A gate for casting molten material, including smelting basalt, in spin-casting molds. The gate includes a curved channel, and means for cooling the channel so as to attain a temperature required for mold spinning operations. The channel includes a main vertical section having a steep impact zone, a drawn-back inlet section and an inclined horizontal end section.